Patent Application
20250007270
Although conventional electromechanical circuit breakers have a proven record as effective and reliable devices for circuit protection, emerging power distribution technologies and architectures, such as DC microgrids, require improved interruption performance characteristics (e.g., faster switching speed). With the latest developments of advanced power semiconductor technologies, research and development in solid state circuit breakers have increasingly spurred. However, higher voltage withstand capability, higher efficiency, extremely fast turn-on, higher reliability, and cost-effectiveness are necessary attributes for the widespread adoption of solid state circuit breakers in the future power grid. North American Electric Reliability Corporation (NERC) and IEEE standards require distribution grid equipment to withstand 2× rated voltage to survive during normal or weather-related conditions (e.g., hurricanes, floods, lightning). Current systems have difficulty in meeting these requirements.
In one implementation, an apparatus includes a solid state circuit breaker to couple between a distribution grid network and a power conversion system. The solid state circuit breaker includes at least one switch circuit and a controller. The at least one switch circuit may include: a plurality of modules, each comprising: at least one bidirectional switch formed of a first bare die power transistor and a second bare die power transistor, the first bare die power transistor having a first terminal coupled to a first terminal of the second bare die power transistor; a surge protection device coupled in parallel with the bidirectional switch; a bypass switch coupled in parallel with the at least one bidirectional switch; and a voltage detector coupled to the at least one bidirectional switch to detect a voltage across the at least one bidirectional switch and output a first feedback signal. The controller is coupled to the plurality of modules, and is to receive the first feedback signal from the plurality of modules and control the bypass switch of at least one of the plurality of modules based at least in part on the first feedback signal from the at least one module.
In an embodiment, the first bare die power transistor is inverse series coupled with the second bare die power transistor. The plurality of modules may be coupled in series, and at least one of the plurality of modules comprises a redundant module.
In an embodiment, the plurality of modules each further comprises at least one temperature sensor to detect a temperature of the module and send a thermal feedback signal to the controller. The controller may be configured to control the bypass switch of at least one of the plurality of modules based at least in part on the thermal feedback signal from the at least one module.
In an embodiment, the first bare die power transistor and the second bare die power transistor are adapted to a circuit board. The apparatus may further comprise an enclosure having the plurality of modules. The apparatus may further comprise a dielectric fluid adapted within the enclosure, the dielectric fluid to provide cooling to the plurality of modules. The dielectric fluid may be at least one of mineral oil, vegetable oil, or silicone fluid.
In one embodiment, the apparatus further comprises a surge voltage blocker circuit coupled to the solid state circuit breaker, where the surge voltage blocker circuit is to provide lightning protection to the power conversion system. The at least one switch circuit may include a plurality of switch circuits to couple in series between the distribution grid network and the power conversion system. The apparatus may further comprise a system controller to receive health information from the plurality of switch circuits and to control at least one of the plurality of switch circuits based at least in part on at least some of the health information.
In another implementation, a system comprises: an enclosure; a plurality of first converters adapted within the enclosure to receive grid power at a distribution grid voltage and convert the distribution grid voltage to at least one second voltage, each of the plurality of first converters comprising a first plurality of solid state switches adapted on a circuit board as bare dies; at least one high frequency transformer adapted within the enclosure, the at least one high frequency transformer coupled to the plurality of first converters to receive the at least one second voltage; a plurality of second converters adapted within the enclosure and coupled to an output of the at least one high frequency transformer to receive the at least one second voltage and convert the at least one second voltage to at least to a third voltage; and a dielectric fluid adapted within the enclosure, the dielectric fluid to provide dielectric isolation. The plurality of first converters, the at least one high frequency transformer, and the plurality of second converters may be immersed within the dielectric fluid.
In an embodiment, each of the plurality of second converters comprises a second plurality of solid state switches adapted on the circuit board as bare dies. The first plurality of solid state switches may be adapted on the circuit board via conductive means. The conductive means may be at least one of solder bumps or bond wires. The dielectric fluid may provide insulation to at least the plurality of first converters.
In yet another implementation, a power module includes: at least one circuit board; a plurality of low frequency (LF) bridge circuits adapted on the at least one circuit board, each of the plurality of LF bridge circuits comprising a first plurality of bare die power transistors adapted to the at least one circuit board to receive an incoming voltage and output a DC voltage; a plurality of DC buses adapted on the at least one circuit board, each of the plurality of DC buses coupled to receive the DC voltage from one of the plurality of LF bridge circuits; a plurality of high frequency (HF) bridge circuits adapted on the at least one circuit board, each of the plurality of HF bridge circuits comprising a second plurality of bare die power transistors adapted to the at least one circuit board, where each of the plurality of HF bridge circuits is coupled to one of the plurality of DC buses to receive the DC voltage and output a second voltage; and a first controller adapted on the at least one circuit board.
In one embodiment, the at least one circuit board comprises a first circuit board and a second circuit board, the first circuit board adapted in opposing relation to the second circuit board via at least one frame member, to form an enclosure for the power module. The power module may be adapted in an enclosure of a power conversion system, the enclosure comprising a dielectric fluid that is a cooling medium for the power conversion system. The at least one circuit board may be immersed in the cooling medium.
In various embodiments, an efficient and self-healing solid state circuit breaker is provided that may be used in connection with a variety of power conversion systems, including grid systems, microgrids, solar and wind systems, energy storage systems, electric vehicle (EV) charging systems, and so forth. This circuit breaker may be implemented in a modular configuration, with a given number of modular bidirectional switches provided to enable protection for different use cases. In addition, the circuit breaker can include optional lightning protection that can detect a surge voltage created by lightning strikes and shunt the solid state circuit breaker to ground to dissipate the lightning energy.
Referring now to
As shown, the source terminals of MOSFETs M1, M2 are coupled together. Each MOSFET M1, M2 has a gate terminal that is controlled by a gate drive signal issued from a corresponding gate driver 1141-4. The drain terminals of MOSFETs M1, M2 are respectively coupled to prior or successive BDSs 115. As further shown, MOSFET M1 of first switch module 1101 has a drain terminal coupled to an input node, and MOSFET M2 of fourth switch module 1104a drain terminal of MOSFET M2 of BDS 1154 coupled to an output node. As further shown, each BDS 115 includes parallel-connected diodes coupled between the drain and source terminals of each MOSFET M1, M2. Each BDS 114 also includes at least one temperature sensor such as temperature sensor 1131-4, which in an embodiment may be implemented as a thermistor.
Still with reference to
As further shown, a bypass switch 1301-4 (which may be implemented as an electromechanical relay) also couples in parallel with each corresponding BDS 115, controlled by a bypass control signal (BPC1-4) received from an IBDS controller 150 (described below). Also a voltage detector 1401-4 couples to each corresponding BDS 115 to detect a voltage and provide a feedback signal (FDBK1-4). In some cases, voltage detector 140 may further include filtering circuitry to filter the detected voltage in providing the feedback signal.
Still with reference to
Still referring to
As illustrated, controller 150 receives feedback information from switch modules 110, including the thermal and voltage feedback information described above. Based at least in part on this information, controller 150 may send bypass control signals (BP(1-4)C) to corresponding bypass switches 130 to cause a given bidirectional switch 115 to be bypassed.
In addition, controller 150 may communicate health information with other IBDSs of a given system (such as other IBDSs of a circuit breaker) and/or a system controller. To this end, as also shown in
IBDS controller 150 is configured to monitor the health and temperature of switch modules 110. During start-up, IBDS controller 150 executes a self-testing routine and if a failure is detected in any BDS, the failed BDS is bypassed by bypass switch 130. Hence, IBDS 100 has the capability of detecting failure and self-healing itself for reliable operation.
In one implementation, IBDS 100 is a modular 2800V switch circuit that is configured with built-up bare die SiC MOSFETs with integrated overvoltage and overcurrent protection. In one or more embodiments, IBDS 100 can withstand 20% temporary overvoltage or 3360V for a duration on the order of approximately one minute.
While four BDSs 110 are coupled in series in the embodiment of
For another embodiment, for a target of a continuous current of 250 amperes (A) and a peak current of 2500 A, a bare die SiC MOSFET available from Cree (CPM3-1700-R020E) may be used, with 10 of these MOSFETs paralleled for peak current handling. Although shown at this high level in the embodiment of
In a particular embodiment, a circuit breaker formed of multiple IBDS's can be configured to achieve desired target requirements. For example, in one embodiment, a circuit breaker can be implemented as a 20 kV modular, scalable, ultra-efficient, and mega-watts solid state circuit breaker with super-fast interruption capability in both medium voltage (MV) AC and DC grids, which may operate at voltages between approximately 1000V and 64 kilovolts (kV), and more typically between approximately 4000V and 34 kV. Such embodiment can withstand 2× rated voltage for 1 minute and can be equipped with optional shunt lightning protection.
Referring now to
Circuit breaker 200 is implemented with additional optional shunt protection via a shunt protection circuit 210. As illustrated, shunt protection circuit 210 may be implemented using another plurality of IBDSs, namely shunt IBDSs 100S1-100SN. In one embodiment, each shunt IBDS may be configured the same as IBDS 100 shown in
As further shown in
In one or more embodiments, circuit breaker 200 may be enclosed in a hermetically sealed container, and cooled by forced dielectric fluid for efficient heat removal, less variability of ambient temperature, and extending the life of the system. Although embodiments are not limited in this regard, in different implementations the dielectric fluid may be mineral oil, vegetable oil, silicone fluid, and/or combinations of two or more of these. In yet other implementations, other dielectric fluids such as castor oil, fluorocarbons, liquid nitrogen, liquid helium, and/or sulfur hexafluoride may be used.
In still other cases, other dielectric fluids may be used, such as transformer oils (mineral oil with additives), vegetable oils, engineered fluids (oils), gas-to-liquid (GTL) fluids such as Risella™ X 415 (which is rated at greater than 30 KV) or another immersion cooling fluid such as S3X (both available from Shell Corporation). And in other cases another single phase or two phase cooling liquid such as NOVEC™ or Fluorinert™ (both available from 3M Corporation) may be used. Although shown at this high level in the embodiment of
With an arrangement as in
Referring now to
As shown, method 300 may begin by receiving voltage and temperature feedback information from switch modules of the IBDS (block 310). This feedback information may be received in the controller, e.g., via communications from one or more temperature sensors and voltage detectors. Based at least in part on this feedback information, it may be determined whether a voltage or temperature of a given switch module exceeds a corresponding threshold (diamond 320). If not, no further operations occur and control passes back to block 310 for receipt of further feedback information.
Instead if it is determined that the feedback information indicates that such threshold has been exceeded, control passes to block 330. At block 330 the IBDS controller may send a bypass control signal to a corresponding bypass switch of the switch module. In response to this bypass control signal, the bypass switch causes bypass of the bidirectional switch, e.g., by closing a bypass path. As a result, the IBDS may continue to operate, albeit with fewer bidirectional switches available.
As further shown in
Referring now to
As shown, method 400 begins by receiving health information from at least one IBDS and input telemetry information (block 410). This health information may be sent by IBDS controllers at periodic intervals and/or on occurrence of a change in health status (e.g., an overtemperature or overvoltage event, a bypass of a bidirectional switch, a failure or so forth). This health information may be sent via fiber optic communication. In turn, the input telemetry information may include health information, temperature, over voltages, voltage unbalance across BDS's, and bypass status, and/or other information.
At block 420, the system controller analyzes the health information and input telemetry information. Based that least in part on this information, it may be determined whether an anomaly is detected (diamond 430). If not, no further operations occur and control passes back to block 410 for receipt of further health and/or telemetry information.
When an anomaly is detected, control passes to diamond 440 to determine whether the anomaly indicates that a lighting threshold has been exceeded. If so, control passes to block 460, where a shunt protection circuit is enabled and the IBDSs are disabled, thus directing the lightning surge to ground. Instead if the anomaly does not exceed the lightning threshold, control passes to block 450 where a bypass command is sent to at least one IBDS to cause it to be bypassed. Also, the system controller may cause a communication network to be reconfigured, to remove the bypassed IBDS. Understand while shown at this high level in
Embodiments may be incorporated into many different types of power conversion systems. Some examples include power conversion systems having configurable modules such as disclosed in U.S. Pat. No. 11,557,957, issued Jan. 17, 2023, the disclosure of which is hereby incorporated by reference in its entirety. Referring now to
As shown, circuit boards 510 are adapted in opposing relation via a pair of frame members 520. Frame members 520 may join to circuit boards 510 via a plurality of fasteners 525; of course the coupling may be made in other manners in other implementations. Frame members 520 may be formed of fiberglass, in an embodiment. Further, although
With this arrangement, the circuit boards and frame members form an enclosure for the power module. While termed an “enclosure,” understand that this enclosure is not fully closed. As such, when power module 500 is adapted into a hermetically sealed system enclosure, the electronic components, including the bare die switches (e.g., IGBTs, SiCs or other transistors), capacitors, integrated circuit packages and so forth may be immersed within and cooled by a dielectric fluid within the sealed system enclosure. In different embodiments, the dielectric fluid may be mineral or vegetable oils.
As shown, a bare die semiconductor switch 545 directly couples to a heat sink 540. In one or more embodiments, heat sink 540 may be a forged copper heat sink that is suitable for attaching bare dies. In certain implementations there may be some type of thermal interface material adapted therebetween. In turn, bare die switch 545 couples to circuit board 510 via contacts 546. In one embodiment, contacts 546 may be implemented as solder bumps and/or bond wires. Of course other contact mechanisms such as clips or compression springs also may be used.
In different implementations, a circuit board may house a given number of power stages. For example, in one embodiment each circuit board 510 may house 3 independent power stages (both low frequency and high frequency components and DC bus of the power stage, as well as a corresponding controller). In such embodiment, power module 500 may provide 6 independent power stages, by way of the inclusion of 2 independent circuit boards 510, each housing 3 independent power stages.
In the embodiment shown, each independent heat sink 540 may be associated with a given switch 545 (e.g., IGBT) of a stage. That is, in an embodiment an independent heat sink may be present for each bare die switch of the first stages and second stages. In a particular embodiment, there may be 24 individual heat sinks, each associated with one of the bare die switches.
Still with reference to
Referring now to
A surge voltage blocker circuit in accordance with an embodiment can be incorporated in many different system types, including a variety of power conversion systems such as EV charging systems, including those illustrated in
Referring now to
More specifically, embodiments may be used for use with distribution grid networks that provide power at medium voltage levels (e.g., between approximately 1000V and 35000V) and at a low frequency (e.g., 50 or 60 Hertz (Hz)). For ease of discussion, understand that the terms “grid,” “grid network” or “distribution grid network” are to be used interchangeably to refer to a power distribution system that provides medium voltage power at low frequency. With embodiments herein, an EV charging system such as charging system 600 may directly couple to a medium voltage distribution grid network (which may be an AC voltage grid or a DC voltage grid) without an intervening power transformer.
In this way, EV charging system 600 may directly receive incoming grid power with a grid voltage at a medium voltage level and a low frequency. As used herein, the terms “direct connection” and “direct coupling” with respect to an EV charging system mean that this system receives distribution grid power at a distribution grid network-provided grid voltage at a distribution grid network low frequency without presence of intervening components. Note that an EV charging system may couple to a grid network through circuitry including a solid state circuit breaker (possibly including an associated surge voltage blocker circuit) as described herein, and still be considered to be in a “direct coupling” with the grid network. Charging system 600 may be implemented as a modular facility. Still further as the need for a power transformer is avoided, EV charging system 600 may be implemented with a relatively small and low cost arrangement.
Still with reference to
Charging system 600 includes a grid-tie module 620. In embodiments herein, grid-tie module 620 may be configured to receive grid power at an incoming grid voltage (which may be an AC or DC voltage) and perform an initial conversion of the incoming grid voltage to a voltage that is at different magnitude and/or frequency. Depending on implementation, grid-tie module 620 may convert the incoming grid voltage to one or more DC or AC voltages at different magnitude or frequency. To this end, grid-tie module 620 interfaces with medium voltage AC or DC grid network 650 and utilizes power electronics converters to convert the AC or DC grid voltage to a voltage that is at different magnitude and/or frequency. Grid-tie module 620 may include multiple stages that may be isolated from each other. In other implementations, at least some of these stages may be cascaded together to increase voltage capabilities.
In particular embodiments herein, grid-tie module 620 may include power electronics-based converters to convert the incoming AC or DC grid voltage. As an example, grid-tie module 620 may include H-bridge power converters to receive the incoming grid voltage and perform a voltage/frequency conversion, e.g., to a DC voltage. In turn, grid-tie module 620 may further include a first stage of a DC-DC converter to convert the DC voltage to a high frequency AC voltage (e.g., a square wave voltage) at a given high frequency (e.g., between 5 kilohertz (kHz) and 100 kHz).
As further illustrated in
Still referring to
Continuing with the above discussion in which an AC voltage is output from transformer network 630, vehicle chargers 640 may include an AC-DC converter as well as a DC-DC converter to provide charging capability at a desired charging voltage and/or charging current.
As shown in
To effect control of EV charging system 600, at least one controller 650 may be present. In various embodiments, controller 650 may include one or more central processing units (CPUs) or systems on chip (SoCs), a dedicated microcontroller or other programmable hardware control circuit such as programmable logic. In one embodiment, controller 650 may form a distributed control architecture. In any case, controller 650 may be configured to execute instructions stored in one or more non-transitory storage media. Such instructions may cause controller 650 to automatically and dynamically control charging voltages and/or charging currents depending upon capabilities and requirements of charging stations 660 and/or connected EVs 665.
Controller 650 may be configured to control, in addition to one or more configurable charging modes, one or more generation and/or storage modes, in which energy stored in one or more batteries of an EV may be stored within a storage within or coupled to EV charging system 600 (such as one or more batteries (not shown for ease of illustration in
In still further implementations an EV charging system also may include capabilities to provide load power to a variety of AC loads, such as industrial facilities or so forth. In addition, the EV charging system may be configured to receive incoming energy, such as from one or more photovoltaic arrays or other solar panels and provide such energy, either for storage within the EV charging system, distribution to the grid and/or as charging power to connected EVs.
Referring now to
As illustrated in
Thus EV charging system 600 couples directly to a distribution network and provides a regulated fixed DC voltage to one or more dispensers 660. In one or more embodiments, dispensers 660 may receive a fixed DC voltage (e.g., at 1000V) and provide an appropriate charge voltage or charge current as requested by each EV 665. Note that dispensers 660 may provide electrical isolation between each EV 665. In other implementations, a charging system may include an integrated dispenser (not separately shown) to which a medium or heavy duty EV 665 may couple, such as for highway truck charging.
Yet other implementations are possible. Referring now to
As shown with regard to representative charging platform 6701, included is a DC/DC converter 672 to which a plurality of switches (SW #1-SW #m) may couple. As such, EV charger DC/DC converter 672 is shared among multiple EV dispensers 660. As illustrated, each switch couples to a corresponding dispenser 6601-m to which a given EV 665 (part of an EV fleet) may be coupled. EV charger DC/DC converter 672 may provide isolation and a charging voltage or charging current requested by EV 665
In this embodiment, charging system 602 may provide a low-cost solution for fleet EV charging. The configuration can charge m×n EVs (where m is the number of dispensers per platform, and n is the number of platforms) during off duty (e.g., overnight). In operation, switches SW can switch on dispensers 660 to charge EVs 665 in sequence. Using this configuration minimizes the required power rating of converters since the vehicles may charge in sequence. For example, charging system 602 can be rated at 900 kW that provides 600A at 1500V DC. The EV charger DC/DC converter 672 power rating can be 150 kW that can provide a maximum of 150 kW of power to EV 665 that is being charged by selection of a given switch SW
Furthermore a controller (e.g., a programmable logic controller) may control the charging functions of platforms 670 based on temperature of EV battery or state of charge to optimize the battery life and/or charging times. By switching the charging between EV's 665 of a platform based on temperature and/or state of charge, speed of charging in a platform increases and the life of the battery may be extended. Understand that variations and modifications of implementations of the embodiments described herein may lead to other fleet charging configurations.
Referring now to
However in this embodiment, system 700 includes at least one DC-AC load converter 735 to provide AC power to a facility 770. As further shown, system 700 also includes a solar converter 738 that may couple to a solar photovoltaic panel 780. In this way, incoming solar energy can be provided to grid network 750, to EV charging stations 760 and/or stored in an energy storage (such as a battery system of system 700 (not shown for ease of illustration in
As described above, different configurations of EV charging systems are possible. Referring now to
Incoming grid power is received, after coupling through a solid state circuit breaker (and possibly a surge voltage blocker circuit) as described herein, at a given grid voltage via input nodes 805a, 805b. Although embodiments are not limited in this regard, in
The incoming voltage is provided to a plurality of input stages, each of which may include multiple H-bridge converters. More specifically, a plurality of input stages 8101-810n are shown that are cascaded together. Each input stage may include a grid-side converter 8121-n (shown as an AC-DC converter). In turn each grid-side converter 812 couples to a DC-AC converter 8141-814n of a given DC-DC converter 8151-815n. Thus each grid-side converter 812 receives an incoming grid AC voltage and converts it to a DC voltage, e.g., at the same or different voltage magnitude. While embodiments may typically implement converters 812 and 814 that are symmetric, it is also possible for there to be asymmetric configurations across power stages.
In an embodiment, each grid-side converter 812 may be implemented as an H-bridge converter including low voltage or medium voltage switches, e.g., SiC devices (which may be implemented as bare dies as described above). In other embodiments, each grid-side converter 812 may be formed as a multi-level rectifier. The resulting DC voltages are in turn provided to corresponding DC-AC converters 814 that act as an input stage of an isolated DC-DC converter 815. In embodiments, converters 814 may be implemented as H-bridge converters to receive the DC voltage and convert it to a high frequency AC voltage, e.g., operating at a frequency of up to 100 kHz. While a square wave implementation is shown in
The high frequency voltage output from converters 814 may be provided to a corresponding primary winding of a transformer 820, namely a high frequency transformer. While shown in
In any event, the galvanically isolated outputs at the secondary windings of transformer 820 may be provided to a plurality of output stages 8301-830o. As such each output stage 830 includes an AC-DC converter 8321-832o (of a DC-DC converter 815). Thereafter, the output DC voltage may be further adjusted in magnitude in corresponding load-side converters 8351-835o (and 8351-835o).
As illustrated, output stages 830 thus include a given output stage (namely stage 832) of a DC-DC converter 815 and a load-side converter 835. As shown in
For example, in other cases a modular high frequency transformer may be used. Referring now to
Incoming grid power is received, after coupling through a solid state circuit breaker (and possibly a surge voltage blocker circuit) as described herein, at a given grid voltage via input nodes 905a, 905b. The incoming voltage is provided to a plurality of input stages, each of which may include multiple H-bridge converters. More specifically, a plurality of power converter stages 9101-910n are shown. Each stage 910 may include a grid-side converter 9121-n (shown as an AC-DC converter) and a DC-AC converter 9141-914n of a given DC-DC converter 9151-915n. Via independent transformers of DC-DC converters 915, a resulting electrically isolated DC voltage is provided to an AC-DC converter 9321-932n and thereafter to a load-side converter 9341-934n. In one embodiment, each load-side converter 9341-934n may provide a voltage to the load, e.g., connected electric vehicles. However here note that potentially different amounts of load-side converters 934 may be cascaded to provide a given DC voltage to a load (e.g., EV charging station). As one example, a first set of load-side converters 9341-934j may provide a first charging voltage of approximately 1500 volts via output nodes 945a,b. And a second set of load-side converters 934j+1-934n may provide a second charging voltage of approximately 900 volts via output nodes 945c,d.
Referring now to
In this implementation, output stages are implemented as port rectifiers 10301-1030m. As shown, each port rectifier 1030 includes at least one AC-DC converter (e.g., AC-DC converters 10321-1032m). As illustrated in
As described, a circuit breaker in accordance with an embodiment is a modular, cost-effective, highly reliable, and ultra-efficient solid state circuit breaker with super-fast interruption capability that can be used in both medium voltage AC and DC power grids, while withstanding 2× rated voltage for at least a minute.
Through using redundant sections, highly reliable bare die SiC MOSFET's, and an innovative cooling mechanism, a solid state breaker in accordance with an embodiment possesses very high reliability that well exceeds a reliability target of greater than 30,000 operating cycles.
While the present disclosure has been described with respect to a limited number of implementations, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations.
