CONTROL OF A DC-DC CONVERTER TO SUPPLY A CONSTANT CURRENT TO A PULSED LOAD

Abstract

There are provided systems and methods comprising, for a power supply which has an output electrically coupled to at least one pulsed load, generating a signal VOV informative of a voltage VOUT at the output of the power supply, generating a signal VIload informative of a current Iload required by the at least one pulsed load, wherein, for at least one given period of time, the current Iload comprises a series of pulses, generating a signal VIin informative of a current Iin at an input of the power supply, feeding the signal VOV, the signal VIload and the signal VIin to a controller of the power supply, and controlling, by the controller, the current Iin such that the signal VIin which is informative thereof, meets a predefined relationship with the signals VOV and VIload.

Description

PRIORITY

The patent application claims priority of IL293057, filed on May 16, 2022.

TECHNOLOGICAL FIELD

The invention is in the field of control of a power supply coupled to a pulsed load.

BACKGROUND

A pulsed load or switched load is a load which requires a large supply of power intermittently.

A power supply (such as a DC-DC converter) provides energy to the pulsed load. In order to mitigate the impact of the pulsating requirement of the pulsed load on the power supply, some prior art solutions use a plurality of intermediate converters (multi-stage converters) and heavy filters. These solutions are costly and not optimal in terms of efficiency.

References considered to be relevant as background to the presently disclosed subject matter are listed below (acknowledgement of the references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter):

• • U.S. Ser. No. 10/218,264;
  • U.S. Pat. No. 8,878,505;
  • U.S. Ser. No. 10/298,122; and
  • U.S. Ser. No. 10/056,830.

There is therefore a need to propose new systems and methods to control a power supply coupled to a pulsed load.

GENERAL DESCRIPTION

In accordance with certain aspects of the presently disclosed subject matter, there is provided a method comprising, for a power supply which has an output electrically coupled to at least one pulsed load: generating a signal V_OV informative of a voltage V_OUT at the output of the power supply, generating a signal V_Iload informative of a current I_load required by the at least one pulsed load, wherein, for at least one given period of time, the current I_load comprises a series of pulses, generating a signal V_Iin informative of a current I_in at an input of the power supply, feeding the signal V_OV, the signal V_Iload and the signal V_Iin to a controller of the power supply, and controlling, by the controller, the current I_in such that the signal V_Iin which is informative thereof, meets a predefined relationship with the signals V_OV and V_Iload.

In addition to the above features, the method according to this aspect of the presently disclosed subject matter can optionally comprise one or more of features (i) to (xviii) below, in any technically possible combination or permutation:

• • i. the amplitude of I_in is constant according to a stability criterion over at least part of the given period of time;
  • ii. said controlling of the current I_in by the controller according to the predefined relationship induces the power supply to generate, at its output, a current I_out which matches an average of I_load according to a matching criterion over at least part of the given period of time;
  • iii. the current I_out is constant according to a stability criterion over at least part of the given period of time;
  • iv. the voltage V_OUT is associated with an acceptable voltage range comprising a minimal acceptable value V_OUT,min and a maximal acceptable value V_OUT,max, wherein the signal V_OV is informative of whether the voltage V_OUT is within the acceptable voltage range;
  • v. the voltage V_OUT is within the acceptable voltage range, the signal V_OV remains within a different voltage range between a first value V_OV,1 and a second value V_OV,2;
  • vi. the second value V_OV,2 is determined for a maximal average current I_load required by the pulsed load during given conditions of operation, such that, according to said predefined relationship, V_Iin=V_Iload;
  • vii. when the voltage V_OUT is above the maximal acceptable value V_OUT,max, the signal V_OV is set equal to a first maximal value V_OV,max, larger than V_OV,2;
  • viii. the output of the power supply is electrically coupled to an output capacitor, wherein when an average value of the current I_load is increased, an amplitude of discharge of the output capacitor during a pulse of I_load is increased, and the signal V_OV is decreased;
  • ix. the output of the power supply is electrically coupled to an output capacitor, wherein when an average value of the current I_load is decreased, an amplitude of discharge of the output capacitor during a pulse of I_load is decreased, and the signal V_OV is increased;
  • x. the output of the power supply is electrically coupled to an output capacitor, wherein during periods of the given period of time in which I_load does not comprise pulses, I_out enables charging of the output capacitor;
  • xi. the current I_out which is used to charge the output capacitor, is constant according to a stability criterion over at least part of the given period of time;
  • xii. the output of the power supply is electrically coupled to an output capacitor, wherein, during at least one period of the given period of time in which a pulse of current I_load is required by the pulsed load, the power supply generates a current I_out and the output capacitor generates a current I_capacitor, wherein the sum of I_out and I_capacitor matches an amplitude of the pulse of current I_load required by the pulsed load according to a matching criterion;
  • xiii. an input voltage provided to the power supply is down-converted only once before it is fed, at the output of the power supply, to the pulsed load; xiv. the controller induces a decrease of an amplitude of I_in when an amplitude of V_OV increases;
  • xv. the controller induces an increase of an amplitude of I_in when an amplitude of V_OV decreases;
  • xvi. the controller induces an increase of an amplitude of I_in when an amplitude of V_Iload increases;
  • xvii. the controller induces a decrease of an amplitude of I_in when an amplitude of V_Iload decreases; and
  • xviii. the controller controls I_in using the predefined relationship k₁V_Iin+k₂V_OV−k₃V_Iload=V_ref, wherein k₁, k₂, and k₃ are positive parameters, and V_ref is a reference voltage of the controller.

In accordance with certain aspects of the presently disclosed subject matter, there is provided a system comprising a controller operative to control a power supply which has an output electrically coupled to at least one pulsed load, wherein the controller is operative to obtain a signal V_OV informative of a voltage V_OUT at the output of the power supply, obtain a signal V_Iload informative of a current I_load required by the at least one pulsed load, wherein, for at least one given period of time, the current I_load comprises a series of pulses, obtain a signal V_Iin informative of a current I_in at an input of the power supply, and control the current I_in such that the signal V_Iin which is informative thereof, meets a predefined relationship with the signals V_OV and V_Iload.

In addition to the above features, the system according to this aspect of the presently disclosed subject matter can optionally comprise one or more of features (xix) to (xxxviii) below, in any technically possible combination or permutation:

• • xix. the amplitude of I_in is constant according to a stability criterion over at least part of the given period of time;
  • xx. said control of the current I_in by the controller according to said predefined relationship induces the power supply to generate, at its output, a current I_out which matches an average of I_load according to a matching criterion over at least part of the given period of time;
  • xxi. the current I_out is constant according to a stability criterion over at least part of the given period of time.
  • xxii. the voltage V_OUT is associated with an acceptable voltage range comprising a minimal acceptable value V_OUT,min and a maximal acceptable value V_OUT,max, wherein the signal V_OV is informative of whether the voltage V_OUT is within the acceptable voltage range;
  • xxiii. the voltage V_OUT is within the acceptable voltage range, the signal V_OV remains within a different voltage range between a first value V_OV,1 and a second value V_OV,2.
  • xxiv. the second value V_OV,2 is determined for a maximal average current I_load required by the pulsed load during given conditions of operation, such that, according to said predefined relationship, V_Iin=V_Iload;
  • xxv. when the voltage V_OUT is above the maximal acceptable value V_OUT,max, the signal V_OV is set equal to a first maximal value V_OV,max, larger than V_OV,2;
  • xxvi. the system comprises an output capacitor electrically coupled to the output of the power supply, wherein when an average value of the current I_load is increased, an amplitude of discharge of the output capacitor during a pulse of I_load is increased, and the signal V_OV is decreased;
  • xxvii. the system comprises an output capacitor electrically coupled to the output of the power supply, wherein when an average value of the current I_load is decreased, an amplitude of discharge of the output capacitor during a pulse of I_load is decreased, and the signal V_OV is increased;
  • xxviii. the system comprises an output capacitor electrically coupled to the output of the power supply, wherein during periods of the given period of time in which I_load does not comprise pulses, I_out enables charging of the output capacitor;
  • xxix. the current I_out which is used to charge the output capacitor, is constant according to a stability criterion over at least part of the given period of time;
  • xxx. the system comprises an output capacitor electrically coupled to the output of the power supply, wherein, during at least one period of the given period of time in which a pulse of current I_load is required by the pulsed load, the power supply is operative to generate a current I_out and the output capacitor is operative to generate a current I_capacitor, wherein the sum of I_out and I_capacitor matches an amplitude of the pulse of current I_load required by the pulsed load according to a matching criterion;
  • xxxi. an input voltage provided to the power supply is down-converted only once before it is fed, at the output of the power supply, to the pulsed load;
  • xxxii. the controller is operative to induce a decrease of an amplitude of I_in when an amplitude of V_OV increases;
  • xxxiii. the controller is operative to induce an increase of an amplitude of I_in when an amplitude of V_OV decreases;
  • xxxiv. the controller is operative to induce an increase of an amplitude of I_in when an amplitude of V_Iload increases;
  • xxxv. the controller is operative to induce a decrease of an amplitude of I_in when an amplitude of V_load decreases.
  • xxxvi. the controller is operative to control I_in using the predefined relationship k₁V_Iin+k₂V_OV−k₃V_Iload=V_ref, wherein k₁, k₂, and k₃ are positive parameters, and V_ref is a reference voltage of the controller;
  • xxxvii. the system comprises the power supply; and
  • xxxviii. the system comprises the pulsed load.

According to some embodiments, the proposed solution provides control and architecture of a power supply connected to a pulsed load which enables high efficiency operation of the power supply.

According to some embodiments, the proposed solution provides a highly efficient power supply together with a reduction of the manufacturing costs.

According to some embodiments, the proposed solution prevents the pulsating requirement of a pulsed load from significantly impacting operation of the power supply.

According to some embodiments, the proposed solution enables usage of a single stage DC-DC converter to provide energy to a pulsed load.

According to some embodiments, the proposed solution does not require the use of heavy filters.

According to some embodiments, the proposed solution induces smooth behavior of the power supply, notwithstanding the pulsating requirement of the pulsed load.

According to some embodiments, the proposed solution provides efficient control of the power supply, even in the presence of high-frequency pulsed load(s).

According to some embodiments, the proposed solution provides control of the power supply which adapts quickly to changes in the load required by the pulsed load(s).

According to some embodiments, the proposed solution reduces the need for cooling of the system.

According to some embodiments, the proposed solution reduces the weight of the system.

According to some embodiments, the proposed solution proposes a system which is more reliable.

According to some embodiments, the proposed solution increases the MTBF (“Mean Time Between Failures”) of the system.

According to some embodiments, the proposed solution is operative even with high-voltage pulsed load.

According to some embodiments, the proposed solution provides a power supply with a low RMS current at its output (I_out).

According to some embodiments, the proposed solution does not require usage of a filter at the input of the power supply.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

FIG. 1A illustrates an architecture of a system operative to provide energy to a pulsed load;

FIG. 1B illustrates a non-limitative example of a current required by a pulsed load, which includes pulses of current;

FIG. 1C illustrates an embodiment of the architecture of the system of FIG. 1A;

FIG. 2 illustrates an embodiment of a method of controlling a power supply to provide energy to a pulsed load;

FIG. 3A illustrates an embodiment of a conversion of the current required by the pulsed load into a voltage signal informative thereof,

FIG. 3B illustrates an embodiment of an architecture enabling conversion of the current required by the pulsed load into a voltage signal informative thereof,

FIG. 3C illustrates a non-limitative example of the voltage signal informative of the current required by the pulsed load;

FIG. 3D illustrates another non-limitative example of the voltage signal informative of the current required by the pulsed load;

FIG. 4 illustrates a non-limitative example of a voltage at the output of the power supply coupled to the pulsed load, and of a current required by the pulsed load;

FIG. 5 illustrates a non-limitative example of a voltage signal informative of the voltage at the output of the power supply;

FIG. 6 illustrates an embodiment of a conversion of the voltage at the output of the power supply into a voltage signal informative thereof;

FIG. 7 illustrates a non-limitative example of a voltage signal informative of the current at the input of the power supply;

FIG. 8 illustrates a non-limitative example of the current required by the pulsed load, of the DC current generated by the power supply and of the current generated by the output capacitor;

FIG. 9 illustrates an embodiment of a conversion of the current at the input of the power supply into a voltage signal informative thereof;

FIG. 10 illustrates an embodiment of a combination of various signals before their feeding to the controller of the power supply; and

FIG. 11 illustrates a non-limitative example of the current required by the pulsed load, of the DC current generated by the power supply, of the DC current at the input of the power supply, and of the current generated by the output capacitor.

DETAILED DESCRIPTION OF EMBODIMENTS

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the presently disclosed subject matter may be practiced without these specific details. In other instances, well-known methods have not been described in detail so as not to obscure the presently disclosed subject matter.

Attention is drawn to FIG. 1A, which illustrates a controlled power supply 100 electrically coupled to a pulsed load 101.

The power supply 100 is typically a DC/DC converter. For example, it can be a Buck Converter or a Boost Converter. According to some embodiments, the architecture as described in FIG. 1A (or in the other embodiments described hereinafter) enables to feed energy to the pulsed load 101 using a single power supply 100 (e.g., single DC/DC converter, or single Buck Converter, or single Boost converter). This corresponds to a “single stage” converter. In a single stage converter, the input voltage (see V_source in FIG. 1) provided to the power supply is down-converted only once (it is reduced to a lower voltage only once) before it is fed, at the output of the power supply (see V_OUT), to the pulsed load 101. The down-conversion is performed by the power supply 100.

The pulsed load 101 can include a single pulsed load, or a plurality of pulsed loads (in some embodiments, the plurality of pulsed loads can operate synchronously in time). Non-limitative examples of pulsed loads include e.g., a phased-array antenna (including a plurality of tiles), a radar, or other pulsed load applications.

The output 105 of the controlled power supply 100 is electrically coupled (connected) to the pulsed load 101 and to an output capacitor 110. The output capacitor 110 is itself electrically coupled to the pulsed load 101.

The power supply 100 receives energy from a power source (voltage source) 120. In some embodiments, the power source 120 includes a rectified phase of a 3-phase power line having a rectified line voltage. In some embodiments, the power source 120 includes an electrically connected bank of batteries configured to provide a required line voltage. This is however not limitative. The voltage provided by the power source 120 to the power supply 100 is noted V_source. V_source—which is generally a constant voltage (e.g., 320 V—this is however not limitative), and is a given input imposed by the electrical network.

FIG. 1A further illustrates a controller 103, which controls operation of the power supply 100. The controller 103 can be a Pulse Width Modulation (PWM) controller. This is however not limitative. Various signals are generated and fed to the input of the controller 103, which will be discussed hereinafter.

Attention is now drawn to FIG. 1B.

FIG. 1B depicts a non-limitative example of the current I_load, which is required by the pulsed load 101 for its operation over a given period of time (between 10 ms and 22 ms—the period of time between 0 ms and 10 ms can correspond e.g., to a transition period).

As visible in FIG. 1B, current I_load includes a series of pulses (also called bursts).

Note that the representation of FIG. 1B, in which a perfect square signal is depicted, is schematic, and the pulses of the current I_load may include a slope (caused by a non-zero rise time). The profile of I_load in the period of time represented in FIG. 1B corresponds to an alternance over time between:

• • pulses 111 of current intensity, and
  • periods of time which are free of pulses, in which the current intensity 112 is equal to zero (or nearly equal to zero).

According to some embodiments, the different pulses of the current intensity I_load are, at least during a given time frame, of the same amplitude (or substantially of the same amplitude). In the non-limitative example depicted in FIG. 1B, the amplitude of each of the pulses is equal to 170 A in a time frame between 10 ms and 22 ms.

In the non-limitative example of FIG. 1B, the duty cycle of the current intensity I_load is equal to 20% (this value is not limitative). The duty cycle corresponds to the ratio between the duration of the pulses and the total period of the waveform.

In the non-limitative example of FIG. 1B, the current intensity I_load has a frequency of 400 Hz (each pulse having a duration/width of 500 μs).

Attention is now drawn to FIG. 1C, which depicts an embodiment of the system of FIG. 1A.

In FIG. 1C, typical components of the power supply 100 are depicted. Note that the components of the power supply depicted in FIG. 1C are only examples. These components include an array 180 of one or more field-effect transistors (FET(s)), a transformer 181 and an inductor 182. Other components and/or additional components can be used as part of the power supply 100. In particular, components typically used in a Buck Converter or in a Boost Converter can be used.

The controller 130 is fed with a plurality of signals. As shown in FIG. 1C, a combiner 150 can perform operations on the plurality of signals. The output of the combiner 150 is fed to an input of the controller 130. Note that the combiner 150 can be part of the controller 130 or external to it.

Attention is now drawn to FIG. 2.

A signal (e.g., voltage signal), noted V_Iload, is generated (operation 200). V_Iload is informative of the current I_load required by the at least one pulsed load 101. In particular, V_Iload can be computed such that its amplitude is representative of the average current required by the at least one pulsed load 101 (in other words, V_Iload is informative of an average of I_load). The average current can be computed over a predetermined period of time, for example over one or more (repetitive) cycles, each cycle comprising a period of time including a peak of current intensity and a period of time in which the current intensity is substantially equal to zero (until the next peak of current intensity is reached).

FIGS. 3A and 3B depict a method which can be used to generate V_Iload. The method includes sampling I_load to obtain a voltage signal V₁. A sampler 329 can be used. The sampler 329 can include e.g., a current transformer, a resistance, etc. (this is not limitative).

The method further includes determining (operation 310) an average V₁ of the voltage signal V₁ over a predetermined period of time T. In some embodiments, the predetermined period of time T can be set as corresponding to the highest PRI (Pulse Repetition Interval) of the pulsed load 101. Indeed, according to some embodiments, the operator of the pulsed load 101 can provide the highest PRI under which the pulsed load 101 is expected to operate. As a consequence, T can be selected as equal to this value, or can be selected as higher than this value by a factor of e.g. 10% (this value is not limitative).

The average V₁ of V₁ can be determined using a standard module 331, which can include electrical components such as a resistor and a capacitor.

At the end of each period of time T, the average V₁ is provided (operation 320) to a sample and hold circuit 333. The sample and hold circuit 333 acts as a “memory”. The output of the sample and hold circuitry 333 can correspond to the signal V_Iload (operation 330).

The module 331 repetitively calculates the average of the signal V₁ over the period of time T, which is then transmitted to the sample and hold circuit 333.

In the most demanding operating conditions of the pulsed load 101, the amplitude of each peak of current I_load is maximal, the duration in time of each peak of current I_load is maximal, and the duty cycle of I_load is maximal. The most demanding operating conditions can correspond e.g., to a configuration in which the average current I_load required by this pulsed load 101 is maximal. Note that the data defining the most demanding operating conditions of the pulsed load 101 constitute a known input and are generally provided by the operator of the pulsed load 101.

Assume for example that the most demanding operating conditions of operation (worst case scenario) of the pulsed load 101 correspond to the parameters provided hereinafter: each peak of current intensity I_load is equal to 170 A, with a duration of 500 μs, the duty cycle is equal to 20%, and the PRI is equal to 2.5 msec (frequency of 400 Hz).

In this non-limitative example, under the most demanding operating conditions of operation, the voltage signal V_Iload which is obtained is a constant voltage equal to 6.8V, as visible in FIG. 3C. This value is not limitative and depends on the parameters chosen for the components used in the module 331 and in the sample and hold circuitry 333. Note that the representation of FIG. 3C (and FIG. 3D) is schematic and does not depict the time response that can be required to compute the signal V_Iload. Note that the conversion of I_load under the most demanding operations into a constant voltage V_Iload equal to 6.8V is arbitrary, and another value can be selected.

Assume that the pulsed load 101 currently operates under given conditions of operations for I_load (for example, the most demanding conditions of operation). As long as the pulsed load 101 does not deviate from these given conditions of operation, the value of V_Iload remains the same.

When the pulsed load 101 deviates from the given conditions of operation, the voltage signal V_Iload has a different value. For example, assume that the duty cycle of I_load is reduced by a factor of 2, from 20% to 10%. As a consequence, the voltage signal V_Iload is reduced by the same factor. For example (note that this example is not limitative), the voltage signal V_Iload is now a constant voltage equal to 3.4V (see FIG. 3D). Similarly, if the amplitude of the peaks of I_load is reduced from 170 A to 56 A (division by three) then the voltage signal V_Iload is a constant voltage equal e.g. to 2.26V (division by three). In other words, a linear relationship can be generated between the signal V_Iload and the current I_load.

Any change in the parameters defining I_load will therefore induce a change in V_Iload.

Reverting to FIG. 2, the method includes operation 210, in which a signal V_OV is generated. V_OV is an electrical signal (e.g., a voltage signal) informative of the voltage V_OUT at the output of the power supply 100 (that is to say, the voltage of the output capacitor 110—this is also the voltage at the input of the pulsed load 101).

According to some embodiments, it is desired to obtain a voltage V_OUT which remains within an acceptable voltage range. Indeed, the pulsed load 101 generally requires a constant voltage value. The acceptable voltage range is provided e.g., by the operator of the pulsed load 101, and is a given input. The acceptable voltage range includes a minimal acceptable value V_OUT,min and a maximal acceptable value V_OUT,max. For example, it is desired to have a voltage V_OUT which varies around a main value (e.g., 50V) with a predefined tolerance of variation around this main value (e.g., ±2V). In this case, the acceptable voltage range for V_OUT is [48V; 52V]. These values are not limitative.

The output capacitor 110 can be selected to meet the requirements of the pulsed load 101 under its most demanding operating conditions (which are, as mentioned above, known in advance): maximal allowed variation of the voltage V_OUT (e.g. ±2V), under maximal pulse width of I_load, maximal amplitude of load current I_load and maximal duty cycle.

For example, assume that the maximal amplitude of each peak of current I_load is equal to 170 A, the maximal duration in time of each peak of current I_load is 500 μs, and the maximal duty cycle of I_load is 20%. This implies that the maximal average value of the current I_load is 34 A.

As explained hereinafter, the power supply 100 is controlled to provide a DC current I_out (I_out is substantially constant according to a stability criterion) corresponding to the average of I_load, which, together with the current I_capacitor generated by the output capacitor 110, enable to feed to the pulsed load 101 the required current I_load.

In order to provide a current which matches the maximal peak of current (in this non limitative example, 170 A) periodically requested by the pulsed load 101, the output capacitor 110 (previously charged using a current I_load of 34 A) must provide a current I_capacitor of 170 A−34 A=136 A. As known in the art,

$I_{\mathrm{capacitor}}=C\frac{\mathrm{dV}}{\mathrm{dt}},$

with C the capacitance of the capacitor and dV the voltage variation. We therefore obtain:

$C=\frac{I_{\mathrm{capacitor}}\mathrm{dt}}{\mathrm{dV}}=\frac{\left(136A\right)\left(500\mu s\right)}{2V}=34\mathrm{mF}.$

These values are not limitative. This corresponds to the minimal capacitance required for the output capacitor 110, determined in the most demanding operating conditions of the pulsed load 101. Note that this is not limitative, and a larger capacitance can be used for the output capacitor 110.

As visible in FIG. 4, the signal V_OUT includes a repetitive sequence of two main temporal phases.

In a first phase 400 corresponding to a time period in which there is a peak in the current I_load, there is a drop in the amplitude of V_OUT (in the non-limitative example of FIG. 4, a drop of around 2V is present). This is due to the fact that during a peak of current I_load, the output capacitor 110 generates a current I_capacitor which induces a drop in the voltage V_OUT of the output capacitor 110.

In a second phase 410 corresponding to a time period in which there is no peak in the signal I_load (in this time period the current I_load is substantially equal to zero), the signal V_OUT increases (until a new peak appears in the current I_load, and at that time there is again a drop in V_OUT). In the example of FIG. 4, an increase of 2V is present.

In the example of FIG. 4, the signal V_OUT remains in the acceptable voltage range ([48V; 52V] as defined e.g., by the operator of the pulsed load 101).

In order to ensure that the signal V_OUT remains in the acceptable voltage range, the signal V_OV can be used. As explained hereinafter, the signal V_OV is also used to enable the controller 103 to command the power supply 100 to request/generate a substantially constant current I_in, in order to obtain a substantially constant output current I_out, which is substantially equal to the average of the current I_load demanded by the pulsed load 101. This will be further described hereinafter.

As long as the signal V_OUT remains in the acceptable voltage range, it is converted into a signal V_OV which remains within a predefined voltage range [V_OV,1; V_OV,2]. V_OV,1 is generally selected as a small value, for example 0.5V. Note that this value is not limitative, and another value can be used.

In order to determine V_OV,2, the following computation can be performed.

As explained hereinafter, the controller 103 controls the power supply 100 using a predefined relationship (see Equation 2). Assume for example that the predefined relationship is (note that Equation 1 is an example of Equation 2):

V _{I in} +V _OV −V _{I load} =2*V_ref  Equation 1

V_ref is a reference voltage of the controller 130. Assume for example that V_ref=1.25. As explained hereinafter, V_Iin is an electrical signal (e.g., voltage signal) informative of the current I_in at the input of the power supply 100.

V_OV,2 can be selected such that, for V_OUT=V_OUT,max (for example 52V), V_Iin=V_Iload.

According to the relationship above, this implies that V_OV,2=2*V_ref=2.5V.

Once V_OV,1 and V_OV,2 have been selected, it can set that, for a value of V_OUT which is equal to 50V (corresponding to the middle of the acceptable voltage range), the value of V_OV is also located at the middle of the interval [V_OV,1; V_OV,2]. In the example provided above, a value of V_OUT equal to 50V corresponds therefore to a value of V_OV equal to 1.5V.

The conversion of V_OUT from the interval [V_OUT,min; V_OUT,max] (e.g. [48V; 52V]) to the interval [V_OV,1; V_OV,2] (e.g. [0.5V; 2.5V]) can be performed using different methods.

In some embodiments, a FPGA can be used. In some embodiments, this conversion can be performed using e.g., a differential amplifier and a resistance.

In some embodiments, in order to prevent the signal V_OV from having ripples as the signal V_OUT (when it varies by ±2V), a capacitor can be used to determine an average of the signal V_OV.

Note that in some embodiments, the signal V_OV is informative of an average of the value of V_OUT. When the average of V_OUT is equal to V_OUT,max, then V_OV is set equal to V_OV,2, when the average of V_OUT is equal to V_OUT,min, then V_OV is set equal to V_OV,1, and when the average of V_OUT is equal to

$\frac{V_{\mathrm{OUT},\min }+V_{\mathrm{OUT},\max }}{2}$

then V_OV is set equal to

$\frac{V_{\mathrm{OV},1}+V_{\mathrm{OV},2}}{2}.$

According to some embodiments, when the signal V_OUT is higher than the maximal acceptable value V_OUT,max (for example the signal V_OUT is larger 52V), the signal V_OV is set (see operation 610) as equal to a new value V_OV,max, which is (much) larger than V_OV,2.

As explained hereinafter with reference to Equation 3 (which describes the operation performed by the controller 130 in coordination with the combiner 150), this enables the controller to reduce I_in, and in turn, to bring back V_OUT to the acceptable voltage range.

This can be performed by using e.g., a diode. As long as the signal V_OUT is within the acceptable voltage range, the diode does not operate. When the signal V_OUT is higher than 52V, this diode starts to operate (and can induce charging of a capacitor, and therefore, induces an increase of V_OV). This induces the signal V_OV to reach the value of V_OV,max. Note that V_OV,max can be selected using Equation 3, such that, even under the highest load required by the pulsed load 101 (in which V_Iload=6.8V), the voltage V_Iin (and therefore the current I_in) is set to zero. Intuitively, this means that the power supply 100 should stop providing current to the pulsed load 101 in case the signal V_OUT is very high.

In the example of Equation 1, this yields the following equation (for V_Iin=0 and V_Iload 6.8V).

V _OV,max=2.5+6.8=9.3V

In some embodiments, when the signal V_OUT is lower than 48V (meaning that the signal V_OUT is smaller than the minimal acceptable value V_OUT,min), the signal V_OV can be set equal to a new smaller value V_OV,min (see operation 620), which is smaller than V_OV,1. For example, V_OV,min is equal to 0V. This can be performed by using e.g., a comparator. Intuitively, this means that the power supply 100 should provide maximal current to the pulsed load 101 in case the signal V_OUT is very small.

In the example of FIG. 4, since the average of the signal V_OUT is in the middle of the acceptable voltage range (50V), the signal V_OV depicted in FIG. 5 is substantially equal to 1.5V.

As shown in FIG. 2, another signal, hereinafter noted V_Iin (operation 220), is generated. V_Iin is an electrical signal (e.g. voltage signal) informative of the current I_in at the input of the power supply 100.

FIG. 7 illustrates an example of the signal V_Iin.

A possible embodiment of a conversion of the current I_in into the signal V_Iin is described with reference to FIG. 9.

The method of FIG. 2 further comprises feeding (operation 230) the signal V_OV, the signal V_Iload and the signal V_Iin to the controller 130 of the power supply 100.

Based on these signals, the controller 130 controls the current I_in fed to the power supply 100. In particular, the controller 130 can control opening of one or more field-effect transistors (FET) of the power supply 100 to control the value of I_in. Note that this is not limitative and, in some embodiments, a phase shift controller or another adapted topology can be used.

The controller 130 controls the current I_in such that the signal V_Iin which is informative thereof, meets a predefined relationship with the signals V_OV and V_Iload (see e.g., Equation 3 recited hereinafter). As shown in FIGS. 1A and 1C, a closed loop control is implemented, in which the controller 130 receives as an input the signal V_Iin informative of the current I_in, and controls the current I_in.

Assume that the pulsed load 101 requests a series of current peaks with the same amplitude over a given period of time. After a transition time enabling the current I_in to reach the required value, the controller 130 enables the power supply 100 to request a current I_in for which the predefined relationship is met. Once the predefined relationship is met, the current I_in is a DC current. Since the power supply 100 receives a DC current I_in, it generates at its output a current I_out which is a DC current. Note that due to various factors (noise, etc.), even after a period of stabilization, the amplitude of I_in can vary slightly. According to some embodiments, the amplitude of I_in is constant according to a stability criterion over at least part of the given period of time. The stability criterion can define the maximal peak-to-peak variation which is acceptable for I_in. In some embodiments, the stability criterion defines that the variations in the amplitude of I_in are smaller than or equal to 5% or 10% of the average of I_in, when the system is not in a transition period. For example, the peak-to-peak variation is smaller than 400 mA (this is not limitative).

Similarly, even after a period of stabilization, the amplitude of I_out can vary slightly. According to some embodiments, the amplitude of I_out is constant according to a stability criterion over at least part of the given period of time. The stability criterion can define the maximal peak-to-peak variation which is acceptable for I_out. According to some embodiments, the stability criterion defines that the variations in the amplitude of I_out are smaller than or equal to 0.2. I_out, when the system is not in a transition period (I_out is the average value of I_out). For example, the peak-to-peak variation is smaller than 400 mA (this is not limitative).

The predefined relationship is calibrated to ensure that the DC current I_in has a value which induces generation of a current I_out at the output of the power supply 100 which matches an average of I_load according to a matching criterion over at least part of the given period of time.

The matching criterion can define the maximal acceptable error between I_out and the average of I_load (e.g., 5%—this is not limitative).

For example, assume that current I_load includes peaks of 170 A with a duty cycle of 20% over a given period of time. The average value of the current I_load is equal to 34 A (the most demanding conditions of operation of the pulsed load 101, as explained above). Therefore, the controller 103 needs to control the power supply 100 to request a current I_in, which induces generation of an output current I_out equal to 34 A. The relationship between I_in and I_out can be defined as follows (this is not limitative):

V _out I _out =εV _source I _in

ε is the efficiency of the power supply 100 which is known or can be estimated.

During a period of time (see reference 410 in FIG. 4) in which the pulsed load 101 does not require a peak of current (I_load is equal to zero, or close to zero), the output current I_out charges the output capacitor 110 (this occurs automatically since the pulsed load 101 does not require current in this period of time 410).

During a period of time (see reference 400 in FIG. 4) in which the pulsed load 101 requires a peak of current (I_load is equal to its maximal value), the output current I_out is fed to the pulsed load 101. In addition, since the output capacitor 110 has been previously charged (as explained above), the output capacitor 110 generates an output current I_capacitor. The sum of I_out and I_capacitor matches an amplitude of the pulse of current required by the pulsed load during a peak (according to a matching criterion defining the maximal acceptable error, e.g., 5%, this value being not limitative). In the example mentioned above, in which peaks of 170 A are required by the pulsed load 101 with a duty cycle of 20%, the value of I_capacitor is 136 A. This is illustrated in FIG. 8, in which peaks of the current of 136 A are depicted for I_capacitor. Note that FIG. 8 is schematic and does not represent noise or delays which can be caused by the time response of the system.

Attention is drawn to FIG. 9.

As explained above, the controller 130 controls I_in such that the signal V_Iin which is informative thereof, meets a predefined relationship with the signals V_OV and V_Iload. Assume that in this example, the predefined relationship is V_Iin+V_OV−V_Iload=2. V_ref.

When the pulsed load 101 operates in its most demanding operating conditions for the current I_load (in the non-limitative example used above, this corresponds to a configuration in which each peak of current intensity I_load is equal to 170 A with a duration of 500 μs, the duty cycle is 20%, and the voltage V_OUT varies between 48V and 52V), we have V_OV=1.5V and V_Iload=6.8V. As explained hereinafter, V_ref is a given parameter of the controller 130 (reference voltage) equal e.g., to 1.25V. As a consequence, in order to meet the predefined relationship when the pulsed load 101 operates in its most demanding operating conditions, the signal V_Iin must be equal to 7.8V (V_Iin=2.5+6.8−1.5=7.8V).

The relationship between I_in and I_out can be defined as follows (this is not limitative):

V _out I _out =εV _source I _in

ε is the efficiency of the power supply 100 which is known or can be estimated (for example, ε=0.94).

In the most demanding operating conditions for the current of the pulsed load, we therefore obtain:

$I_{\mathrm{in}}=\frac{V_{\mathrm{out}}{I}_{\mathrm{out}}}{\epsilon V_{\mathrm{source}}}=\frac{50*34}{0.94*320}=5.65A$

Therefore, in the most demanding operating conditions for the current of the pulsed load, the value of V_Iin (7.8V) must represent a current I_in of 5.65 A.

In the architecture of FIG. 9, the current I_in is fed to a current sensor 900. The parameters of the current sensor 900 are selected to ensure that for an input current I_in of 5.65 A, a voltage V_Iin of 7.8V is generated.

In some embodiments, the current I_in is fed to a current sensor which divides the current by a known constant factor, and the output is multiplied by a fixed gain G (to be determined), in order to obtain V_Iin. The gain G is therefore determined such that, for an input current I_in of 5.65 A, the value of V_Iin is equal to 7.8V.

Note that there is a linear relationship between I_in and V_Iin.

Attention is now drawn to FIG. 10.

As mentioned above, the controller 130 controls I_in, in order to ensure that a predefined relationship is met between V_Iin, V_OV and V_Iload.

According to some embodiments, the predefined relationship is defined as follows:

k ₁ V _{I in} +k ₂ V _OV −k ₃ V _{I load} =V _ref  Equation 3

In this relationship, k₁, k₂, and k₃ are positive parameters. In a non-limitative example, k₁=k₂=k₂=½. V_ref is a reference voltage of the controller 130 (this is a given parameter of the parameter—each controller 130 having his own reference voltage).

The relationship provided above is not limitative.

The controller 130 tries to modify V_Iin (by modifying I_in taken by the power supply 100 from the power source 120) in order to have the relationship which is met. Note that V_OV and V_Iload are measured, and V_ref is a predefined constant of the controller 130. The generation of the signals V_OV, V_Iload and V_Iin has been described above.

Assume that the predefined relationship is met, and that the load (current) taken by the pulsed load 101 is decreased. For example, the amplitude of the pulses of I_load is decreased, and/or the duty cycle of the pulses of I_load is decreased and/or the width of each pulse of the current I_load is decreased, etc.

As a consequence, the output capacitor 110 will be less discharged during a pulse of current taken by the pulsed load 101 (since there is a linear relationship between the current and the voltage in a capacitor). For example, if the output capacitor 110 formerly discharged from 52V to 48V during a pulse of I_load, it is now discharged from 52V to 50V.

Therefore, the variations in the voltage V_OUT at the output capacitor 110 will have a smaller amplitude (e.g., with an amplitude smaller than 2V). The average of the voltage V_OUT is increased. The value of the signal V_OV will therefore increase. In some cases, the value of V_OUT may reach a value which is above the maximal acceptable value V_OUT,max.

Since V_ref is fixed, in order to maintain the relationship of Equation 3 as true, the controller 130 needs to decrease also the amplitude V_Iin, by decreasing I_in. Since I_in is decreased, I_out at the output of the power supply 100 is decreased, thereby complying with the decrease in I_load. When the predefined relationship is met, the power supply 100 generates, at its output, a current I_out which is equal (or substantially equal) to the new average value of I_load. Indeed, the predefined relationship has been defined for the most demanding conditions of operation, and, in view of its linearity, adapts to other conditions of operation of the pulsed load 101.

Similarly, assume that the predefined relationship is met, and that the load (current) taken by the pulsed load 101 is increased. For example, the amplitude of the pulses of I_load is increased, and/or the duty cycle of the pulses of I_load is increased, and/or the width of each pulse of the current I_load is decreased, etc.

As a consequence, the output capacitor 110 will be more discharged during a pulse of current taken by the pulsed load 101 (since there is a linear relationship between the current and the voltage in a capacitor). For example, if the output capacitor 110 used to be discharged from 52V to 48V during a pulse of I_load, it is now discharged from 52V to 46V.

Therefore, the average value of the voltage V_OUT at the output capacitor 110 is decreased. In some cases, the value of V_OUT may reach a value which is below the minimal acceptable value V_OUT,min. The value of the signal V_OV will therefore decrease. Since V_ref is fixed, in order to maintain the relationship of Equation 3 as true, the controller 130 needs to increase also the amplitude V_Iin, by increasing I_in. Since I_in is increased, I_out at the output of the power supply 100 is increased, thereby complying with the increase in I_load. When the predefined relationship is met, the power supply 100 generates, at its output, a current I_out which is equal (or substantially equal) to the new average value of I_load.

A non-limitative example is provided with reference to FIG. 11.

Assume that the current I_load previously included peaks of 170 A, which have now been reduced to 85 A. The duty cycle remains equal to 20%. This corresponds to an average current I_load of 17A. The other parameters of the pulsed load 101 remain the same. As a consequence, V_Iload decreases from 6.8V to 3.4V. The output capacitor 110 is less discharged, and its average voltage V_OUT increases to around 51V (with variations of ±1V around the average value 51V). Therefore, the signal V_OV also increases. According to Equation 3, this induces the controller 130 to decrease I_in until the relationship is met (the process is iterative until the relationship is met). In particular, the value of V_Iin decreases from its original value 7.8V to a new value 3.9V. This corresponds to a value of I_in=2.82 A, which enables to generate an output current

$I_{\mathrm{out}}=\frac{\epsilon V_{\mathrm{source}}{I}_{\mathrm{in}}}{V_{\mathrm{out}}}=\frac{0.94*320*2.82}{51}=16.63A,$

which matches substantially the average value (17 A) of the current I_load, as requested.

I_out charges the output capacitor 110 during the periods of time in which there is no peak of current. When the pulsed load 101 requires a peak of current, the output capacitor 110 provides peaks of current of around I_capacitor=68 A (since the output capacitor 110 is charged with a current which is divided by two with respect to the most demanding operating conditions of the pulsed load 101, in which I_out=34 A and I_capacitor=136 A).

Assume now that the current I_load previously included peaks of 85A, which have now been increased to 100 A (average of I_load is therefore 20 A). The other parameters of the pulsed load 101 remain the same. As a consequence, V_Iload increases from 3.4V to around 4V. The output capacitor 110 is more discharged, and its average voltage V_OUT decreases to around 50V (with variations of ±2V around the average value 50V) The signal V_OV decreases such that V_Iin reaches its new value.

The controller 130 increases I_in until the relationship is met, which means that value of V_Iin increases from its previous value 3.9V to a new value 4.56V.

This corresponds to a value of I_in=3.30 A, which generates an output current

$I_{\mathrm{out}}=\frac{\epsilon V_{\mathrm{source}}{I}_{\mathrm{in}}}{V_{\mathrm{out}}}=\frac{0.94*320*3.3}{50}=19.8A,$

which matches substantially the average value (20 A) of the current I_load, as requested.

I_out charges the output capacitor 110 during the periods of time in which there is no peak of current. When the pulsed load 101 requires a peak of current, the output capacitor 110 provides peaks of current of around I_capacitor=80 A.

It is to be noted that the various features described in the various embodiments may be combined according to all possible technical combinations.

It is to be understood that the invention is not limited in its application to the details set forth in the description contained herein or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Hence, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for designing other structures, methods, and systems for carrying out the several purposes of the presently disclosed subject matter.

Those skilled in the art will readily appreciate that various modifications and changes can be applied to the embodiments of the invention as hereinbefore described without departing from its scope, defined in and by the appended claims.

Claims

1. A system comprising a controller operative to control a power supply which has an output electrically coupled to at least one pulsed load, wherein the controller is operative to: obtain a signal VOV informative of a voltage VOUT at the output of the power supply,obtain a signal VIload informative of a current Iload required by the at least one pulsed load, wherein, for at least one given period of time, the current Iload comprises a series of pulses,obtain a signal VIin informative of a current Iin at an input of the power supply, andcontrol the current Iin such that the signal VIin which is informative thereof, meets a predefined relationship with the signals VOV and VIload.

2. The system of claim 1, wherein the amplitude of Iin is constant according to a stability criterion over at least part of the given period of time.

3. The system of claim 1, wherein said control of the current Iin by the controller according to said predefined relationship induces the power supply to generate, at its output, a current Iout which matches an average of Iload according to a matching criterion over at least part of the given period of time.

4. The system of claim 3, wherein the current Iout is constant according to a stability criterion over at least part of the given period of time.

5. The system of claim 1, wherein the voltage VOUT is associated with an acceptable voltage range comprising a minimal acceptable value VOUT,min and a maximal acceptable value VOUT,max, wherein the signal VOV is informative of whether the voltage VOUT is within the acceptable voltage range.

6. The system of claim 5, wherein, when the voltage VOUT is within the acceptable voltage range, the signal VOV remains within a different voltage range between a first value VOV,1 and a second value VOV,2.

7. The system of claim 5, wherein the second value VOV,2 is determined for a maximal average current Iload required by the pulsed load during given conditions of operation, such that, according to said predefined relationship, VIin=VIload.

8. The system of claim 5, wherein, when the voltage VOUT is above the maximal acceptable value VOUT,max, the signal VOV is set equal to a first maximal value VOV,max, larger than VOV,2.

9. The system of claim 1, comprising an output capacitor electrically coupled to the output of the power supply, wherein when an average value of the current Iload is increased, an amplitude of discharge of the output capacitor during a pulse of Iload is increased, and the signal VOV is decreased.

10. The system of claim 1, comprising an output capacitor electrically coupled to the output of the power supply, wherein when an average value of the current Iload is decreased, an amplitude of discharge of the output capacitor during a pulse of Iload is decreased, and the signal VOV is increased.

11. The system of claim 1, comprising an output capacitor electrically coupled to the output of the power supply, wherein during periods of the given period of time in which Iload does not comprise pulses, a current Iout provided by the power supply enables charging of the output capacitor.

12. The system of claim 11, wherein the current Iout which is used to charge the output capacitor, is constant according to a stability criterion over at least part of the given period of time.

13. The system of claim 1, comprising an output capacitor electrically coupled to the output of the power supply, wherein, during at least one period of the given period of time in which a pulse of current Iload is required by the pulsed load, the power supply is operative to generate a current Iout and the output capacitor is operative to generate a current Icapacitor, wherein the sum of Iout and Icapacitor matches an amplitude of the pulse of current Iload required by the pulsed load according to a matching criterion.

14. The system of claim 1, wherein an input voltage provided to the power supply is down-converted only once before it is fed, at the output of the power supply, to the pulsed load.

15. The system of claim 1, wherein, according to the predefined relationship, at least one of (i), (ii), (iii) or (iv) is met: (i) the controller is operative to induce a decrease of an amplitude of Iin when an amplitude of VOV increases;(ii) the controller is operative to induce an increase of an amplitude of Iin when an amplitude of VOV decreases;(iii) the controller is operative to induce an increase of an amplitude of Iin when an amplitude of VIload increases; or(iv) the controller is operative to induce a decrease of an amplitude of Iin when an amplitude of VIload decreases.

16. The system of claim 1, wherein the controller is operative to control Iin using the predefined relationship: k1VIin+k2VOV−k3VIload=Vref

17. The system of claim 1, further comprising at least one of the power supply or the pulsed load.

18. A method comprising, for a power supply which has an output electrically coupled to at least one pulsed load: generating a signal VOV informative of a voltage VOUT at the output of the power supply,generating a signal VIload informative of a current Iload required by the at least one pulsed load, wherein, for at least one given period of time, the current Iload comprises a series of pulses,generating a signal VIin informative of a current Iin at an input of the power supply,feeding the signal VOV, the signal VIload and the signal VIin to a controller of the power supply, andcontrolling, by the controller, the current Iin such that the signal VIin which is informative thereof, meets a predefined relationship with the signals VOV and VIload.

19. The method of claim 18, wherein the amplitude of Iin is constant according to a stability criterion over at least part of the given period of time.

20. The method of claim 18, wherein said controlling of the current Iin by the controller according to the predefined relationship induces the power supply to generate, at its output, a current Iout which matches an average of Iload according to a matching criterion over at least part of the given period of time.