Patent Application
20130162048
This application claims the priority of Korean Patent Application No. 10-2011-0140039 filed on Dec. 22, 2011, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a power module capable of suppressing a phenomenon in which an inrush current is generated during a hot swap, and a multi power supply apparatus having the same.
2. Description of the Related Art
Generally, various electronic apparatuses satisfying various needs of users have been variously implemented. These electronic apparatuses may use a power supply apparatus to supply operating power in order to implement various functions therein.
The power supply apparatus may generally adopt a switching mode power supply scheme due to advantages such as power conversion efficiency, miniaturization, and the like.
As this power supply apparatus, there may be a multi power supply apparatus having a plurality of power modules in order to supply large-capacity power to an electronic apparatus requiring the large-capacity power such as a server.
Referring to
Since a failure may be generated in this multi power supply apparatus, the power module may be individually replaced. In this case, a hot swap method of removing only the failed power module and inserting a new power module without entirely cutting power may be used, due to ease in performing maintenance, repairs, and upgrades.
However, in a case in which a single power module is hot-swapped while the multi power supply apparatus is operating, an excessive inrush current may be generated in the newly inserted power module, as shown in
Referring to
The reason why the inrush current is generated during a hot swap as described above is that output voltages of the plurality of power modules connected in parallel with each other do not coincide with each other. An excessive inrush current may cause hot swap failure or damage to an element of the power module due to an overcurrent.
An aspect of the present invention provides a power module capable of suppressing a phenomenon that an inrush current is generated by stopping soft switching and fixing a voltage command value when a voltage level of output power of a power module is higher than that of power applied to a load during a hot swap of the power module, and a multi power supply apparatus having the same.
According to an aspect of the present invention, there is provided a power module including: a DC/DC converting unit converting an input power into a preset DC power; an output controlling unit switched on or switched off according to a difference between a voltage level of the DC power of the DC/DC converting unit and a voltage level applied to a load end to control an output of the DC power; and a controlling unit starting a soft start operation of the DC/DC converting unit during a hot swap and stopping the soft start operation of the DC/DC converting unit when the output controlling unit is switched on.
According to another aspect of the present invention, there is provided a multi power supply apparatus including: a plurality of power modules connected in parallel with each other and supplying a preset power, each of the plurality of power modules including: a DC/DC converting unit converting an input power into a preset DC power; an output controlling unit switched on or switched off according to a difference between a voltage level of the DC power of the DC/DC converting unit and a voltage level applied to a load end to control an output of the DC power; and a controlling unit starting a soft start operation of the DC/DC converting unit during a hot swap in which the power module is replaced and stopping the soft start operation of the DC/DC converting unit when the output controlling unit is switched on.
The controlling unit may increase a voltage command value of the DC/DC converting unit while controlling the soft start operation and fix a corresponding voltage command value as a final voltage command value while controlling the stopping of the soft start operation.
The controlling unit may include an analog to digital converter converting a voltage level of the DC power, a current level of output power of the output controlling unit, and a current level of power transferred to a power coupling line in which the output power is coupled to another output power into respective digital signals; a switching controller controlling the soft start operation of the DC/DC converting unit based on the digital signals converted by the analog to digital converter; and an inrush current prevention controller controlling the switching controller to stop the soft start operation of the DC/DC converting unit when the output controlling unit is switched on or the voltage level of the DC power is higher than the voltage level applied to the load end.
The output controlling unit may include an output switch switched on or switched off according to a switching control signal to output the DC power of the DC/DC converting unit; and an output switching controller providing the switching control signal allowing the output switch to be switched on or switched off.
The power module may further include an electro-magnetic interference (EMI) filtering unit filtering EMI from AC power; a rectifying unit rectifying the filtered AC power; and a power factor compensating unit adjusting a phase difference between a voltage and a current of the rectified power to compensate for a power factor.
The DC/DC converting unit may include a switching unit switching the input power; a transforming unit including a transformer having a primary winding receiving the switched power and a secondary winding forming a preset turns ratio with regard to the primary winding to transform a voltage level; and a rectifying/stabilizing unit rectifying and stabilizing power from the transforming unit.
The switching unit may have a half-bridge, a full-bridge, or a push-full type switch structure.
The rectifying/stabilizing unit may include first and second synchronous rectifying elements respectively connected to both ends of the secondary winding of the transformer to rectify output power; and an inductor and a capacitor connected to a center tap of the secondary winding to stabilize the output power.
The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
Hereinafter, embodiments will be described in detail with reference to the accompanying drawings so that they can be easily practiced by those skilled in the art to which the present invention pertains.
However, detailed descriptions related to well-known functions or configurations will be ruled out in order not to unnecessarily obscure subject matters of the present invention.
In addition, like reference numerals will be used to describe elements having the same or similar functions throughout the accompanying drawings.
Throughout this specification, it will be understood that when an element is referred to as being “connected to another element, it can be directly connected to the other element or may be indirectly connected to the other element with element(s) interposed therebetween.
In addition, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising,” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.
Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
Referring to
Output powers of the first and N-th power modules may be combined to be output as a single power, and the first and N-th power modules may perform a hot swap function in which the power modules maybe replaced in a state in which power is applied to the multi power supply apparatus.
A first power module 100 among the first and N-th power modules will be described by way of example.
The power module 100 may include an electro-magnetic interference (EMI) filtering unit 110, a rectifying unit 120, a power factor compensating unit 130, a DC/DC converting unit 140, an output controlling unit 150, and a controlling unit 160.
The EMI filtering unit 110 may filter electromagnetic interference (EMI) from AC power.
The rectifying unit 120 may rectify the AC power filtered by the EMI filtering unit 110.
The power factor compensating unit 130 may adjust a phase difference between voltage and current of the power rectified from the rectifying unit 120 to compensate for a power factor.
The DC/DC converting unit 140 may switch input power from the power factor compensating unit 130 to convert the input power into a preset DC power.
The output controlling unit 150 may be switched on or switched off according to a difference between a voltage level of the DC power from the DC/DC converting unit 140 and a voltage level applied to a load end to thereby control an output of the DC power.
The controlling unit 160 may control a power conversion operation of the DC/DC converting unit 140. Particularly, the controlling unit 160 may start a soft start operation of the DC/DC converting unit 140 during a hot swap and stop the soft start operation of the DC/DC converting unit 140 when the output controlling unit 150 is switched on.
Referring to
The switching unit 141 may include a plurality of switches to switch input power VS and may have, for example, a full-bridge type switch structure in which it includes first and second switches QA and QB connected in series with each other between both ends of an input power terminal to which the input power Vs is applied and third and fourth switches Qc and QD connected in series with each other between both ends of the input power terminal and connected in parallel with the first and second switches QA and QB as shown in
The transforming unit 142 may include a transformer. The transformer may have a primary winding Np having both ends respectively connected to a connection point between the first and second switches QA and QB and a connection point between the third and fourth switches Qc and QD and receiving the power switched from the switching unit 141, and a secondary winding NS forming a preset turns ratio with regard to the primary winding NP to transform a voltage level of the switched power. In addition, the transformer may include a leakage inductance component Llkg, and the secondary winding NS may have a center tap.
The rectifying/stabilizing unit 143 may include first and second synchronous rectifying elements SRA and SRB respectively connected to both ends of the secondary winding NS and an inductor LO and a capacitor CO connected to the center tap of the secondary winding NS.
The first and second synchronous rectifying elements SRA and SRB may be synchronized with switching of the switching unit 141 and may be alternately switched to rectify power output from the secondary winding NS.
The inductor LO and the capacitor CO may stabilize the power rectified by the first and second rectifying elements SRA and SRB to output the DC power.
The output controlling unit 150 may include an output switch QOR and an output switching controller CON.
The output switch QOR may be switched on or switched off according to a switching control signal to perform a control to output or block the DC power from the DC/DC converting unit 140.
The output switching controller CON may provide a switching control signal controlling the switching on or the switching off of the output switch QOR and control the output switch QOR so as to be switched on when a voltage level of the DC power of the DC/DC converting unit 140 is higher than that of a load end.
The controlling unit 160 may include an analog to digital converter 161, a switching controller 162, and an inrush current prevention controller 163.
The analog to digital converter 161 may convert a voltage level Vo of the DC power of the DC/DC converting unit 140, a current level IO of the output power of the output controlling unit 150, and a current level ILS of power transferred to a power coupling line in which the output power is coupled to another output power into digital signals.
Detected voltage VO[k] of the DC power, detected current IO[k] of the output power, and detected current ILS[k] of the power coupling line may be transferred to the switching controller 162.
The switching controller 162 may control the switching of the switching unit 141 and the switching of the first and second synchronous rectifying elements SRA and SRB based on the detected voltage VO[k] of the DC power, the detected current IO[k] of the output power, and the detected current ILS[k] of the power coupling line.
In addition, the switching controller 162 may control a soft start operation of the switching unit 141 based on the detected voltage VO[k] of the DC power, the detected current IO[k] of the output power, and the detected current ILS[k] of the power coupling line (S1). That is, the switching controller 162 may control a switching degree of the switching unit 141 according to a voltage command value VREF[k] during the hot swap at which the power module is replaced, thereby allowing a voltage level of the DC power of the DC/DC converting unit 140 to be in accordance with the voltage command value, and stepwise increase the voltage command value to control the voltage level of the DC power so as to slowly rise (S3).
In the case in which the voltage level of the DC power of the DC/DC converting unit 140 is higher than that of the load end or the output switching controller CON provides the switching control signal allowing the output switch QOR to be switched on (S2), the inrush current prevention controller 163 may fix a voltage command value in that case as a final voltage command value and then transfer the fixed voltage command value to the switching controller 162, and the switching controller 162 may stop the soft start operation of the switching unit 141 accordingly (S4).
Referring to
However, referring to
Contrary to
As set forth above, according to embodiments of the present invention, when a voltage level of output power of a power module is higher than that of power applied to a load during a hot swap of the power module, soft switching is stopped and a voltage command value is fixed to thereby prevent the generation of an inrush current.
While the present invention has been shown and described in connection with the embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2011-0140039 | Dec 2011 | KR | national |
