Power unit and solid-state transformer

Abstract

The present application provides a power unit and a solid-state transformer, which supplies power to a control module of the power unit through a first auxiliary power circuit and a second auxiliary power circuit, thereby improving the operational reliability of the power unit. The power unit may include a first auxiliary power circuit and a first power circuit, and the first power circuit includes an AC / AC power main circuit and a first control module. The AC / AC power main circuit is coupled to a power grid power supply system, and the AC / AC power main circuit is powered by the power grid power supply system. The input end of the first auxiliary power circuit is coupled to the bus of the AC / AC power main circuit, and the output end of the first auxiliary power circuit is coupled to the first control module. The first auxiliary power circuit adjusts the voltage of the bus of the AC / AC power main circuit to the DC voltage required by the first control module and outputs it to the first control module.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and more particularly, to a power unit and a solid-state transformer. Background Art

[0002] A solid-state transformer (SST), also known as an electronic power transformer (EPT), is a stationary electrical device that combines power electronics conversion technology with high-frequency power conversion technology based on the principle of electromagnetic induction to convert electrical energy of one power characteristic into electrical energy of another (e.g., achieving voltage conversion and energy transfer). Compared to conventional power transformers, SSTs are smaller, can maintain a stable output voltage, and can improve input-side power factor and current harmonics.

[0003] Solid-state transformers (SSTs), when applied to power systems, can improve power quality and stability, enable flexible power transmission, and enable real-time control of power flows in electricity markets. Therefore, SSTs have become a major research topic in power systems.

[0004] Since the power unit in the solid-state transformer SST includes a control module for realizing functions such as controlling and driving the power devices in the power unit, how to provide power to the control module becomes an urgent problem to be solved. Summary of the Invention

[0005] The embodiments of the present application provide a power unit and a solid-state transformer, which can supply power to a control module in the power unit, thereby improving the operational reliability of the control module.

[0006] In a first aspect, an embodiment of the present application provides a power unit, which may include a first auxiliary power supply circuit and a first power circuit, the first power circuit including an alternating current (AC) / alternating current AC power main circuit (referred to as AC / AC power main circuit for short) and a first control module coupled to the AC / AC power main circuit.

[0007] Optionally, the input end of the first auxiliary power supply circuit is coupled to the busbar of the AC / AC power main circuit, and the output end of the first auxiliary power supply circuit is coupled to the first control module; the AC / AC power main circuit includes an input end and an output end, and the input end of the AC / AC power main circuit is coupled to the power grid power supply system (which can be a distribution system or a transmission system).

[0008] Based on the above coupling relationship, the AC / AC power main circuit can be configured to: adjust the first voltage (which can be represented by V1) from the grid power supply system to a second voltage (which can be represented by V2) and output it through the output end of the AC / AC power main circuit (which can be output to the transformer (i.e., the first transformer) in the power unit).

[0009] Furthermore, the first control module can be configured to: detect the state of the AC / AC power main circuit and / or information of the AC / AC power main circuit, and drive the AC / AC power main circuit (can drive the switching tube in the AC / AC power main circuit) according to the state and / or information of the AC / AC power main circuit.

[0010] Furthermore, the first auxiliary power supply circuit can be configured to: convert the voltage of the bus of the AC / AC power main circuit (which can be expressed as V bus The first auxiliary power supply circuit (denoted by V3) is adjusted to a third voltage (denoted by V3) and output to the first control module (ie, the first auxiliary power supply circuit supplies power to the first control module). The third voltage V3 can be used to indicate the DC voltage required by the first control module.

[0011] It should be noted that the state of the AC / AC power main circuit may be the state (including on and off) of a switch (such as a transistor or an insulated gate bipolar transistor (IGBT)) in the AC / AC power main circuit. The information of the AC / AC power main circuit may include the input voltage, input current, output voltage, and / or output current of the AC / AC power main circuit.

[0012] The power unit provided in this application can reliably power the first control module in the first power circuit via the first auxiliary power circuit, thereby improving the operational reliability of the first control module. Furthermore, the power unit eliminates the need for separate isolation equipment, reducing the power supply cost of the first control module and shrinking the size of the power unit.

[0013] In one possible implementation, the power unit may further include a first transformer (such as a high-frequency transformer) and a second power circuit. The second power circuit may include an AC / DC (direct current, DC) power main circuit (referred to as an AC / DC power main circuit) and a second control module coupled to the AC / DC power main circuit. The AC / DC power main circuit may include an input end and an output end.

[0014] Optionally, the input end of the first transformer is coupled to the output end of the AC / AC power main circuit, and the output end of the first transformer is coupled to the input end of the AC / DC power main circuit.

[0015] Based on the above coupling relationship, the first transformer can be configured to adjust the second voltage V2 to a fourth voltage (which can be represented by V4) and output it to the AC / DC power main circuit. The fourth voltage V4 can be used to indicate the AC voltage required by the AC / DC power main circuit.

[0016] Furthermore, the AC / DC power main circuit is configured to rectify the fourth voltage V4 into a fifth voltage (which can be represented by V5) and output it through the output terminal of the AC / DC power main circuit (which can be output to the second auxiliary power supply circuit). The fifth voltage V5 can be used to indicate the DC voltage output by the AC / DC power main circuit.

[0017] Furthermore, the second control module may be configured to detect a state and / or information of the AC / DC power main circuit, and drive the AC / DC power main circuit based on the state and / or information of the AC / DC power main circuit.

[0018] For example, the state of the AC / DC power main circuit may be the state (including on and off) of a switch (such as a transistor or an IGBT) in the AC / DC power main circuit. The information of the AC / DC power main circuit may include the input voltage, input current, output voltage, and / or output current of the AC / DC power main circuit.

[0019] It should be noted that the voltage value of the first power circuit can be higher than the voltage value of the second power circuit. Since the input of the first power circuit is usually AC power from the power grid power supply system and the output of the first power circuit is also AC power, the first power circuit can be called an AC conversion circuit. In addition, the input of the first power circuit is usually high voltage (such as a voltage value of more than 35kV and less than 220kV) or medium voltage (such as a voltage value of more than 1kV and less than 35kV), so the first power circuit can also be called a high voltage power circuit or a medium voltage power circuit.

[0020] It should also be noted that since the output of the first power circuit is coupled to the input of the first transformer, and the output of the first transformer is coupled to the input of the second power circuit, it can be determined that the first transformer converts the high or medium voltage from the first power circuit into a low voltage (e.g., a voltage below 1 kV, also referred to as an AC voltage). Furthermore, the second power circuit converts the low voltage obtained by the first transformer into a DC voltage (this DC voltage is also a low voltage). Therefore, the second power circuit can be referred to as a low-voltage power circuit.

[0021] The present application implements the conversion and transmission from the input to the output of the power unit through the AC / AC power main circuit, the first transformer and the AC / DC power main circuit. At the same time, the first control module is used to implement the reliable driving of the switch tube in the AC / AC power main circuit, and the second control module is used to implement the reliable driving of the switch tube in the AC / DC power main circuit, thereby improving the reliability of the AC / DC power main circuit and the AC / AC power main circuit.

[0022] In one example, the first control module may include a first detection circuit, a first communication circuit, a first control circuit, and a first driving circuit.

[0023] Optionally, the input end of the above-mentioned first detection circuit can be coupled to the AC / AC power main circuit, the output end of the first detection circuit can be coupled to the input end of the first control circuit, the output end of the first control circuit can be coupled to the input end of the first drive circuit, the output end of the first drive circuit can be coupled to the AC / AC power main circuit, the first control circuit is also coupled to the first communication circuit, and the first communication circuit is coupled to the second control module.

[0024] Based on the above coupling relationship, we can further determine:

[0025] The first detection circuit may be used to detect a state and / or information of the AC / AC power main circuit.

[0026] The first control circuit may be configured to transmit a status and / or information of the AC / AC power main circuit to the first communication circuit.

[0027] The first communication circuit may be configured to transmit the status and / or information of the AC / AC power main circuit to the second control module, and transmit the status and / or information of the AC / AC power main circuit from the second control module to the first control circuit.

[0028] After the first communication circuit transmits the status and / or information of the AC / DC power main circuit and the status and / or information of the AC / AC power main circuit (that is, at least one of the status of the AC / DC power main circuit, the information of the AC / DC power main circuit, the status of the AC / AC power main circuit, and the information of the AC / AC power main circuit) to the first control circuit, the first control circuit can also be used to: send a first control command to the first drive circuit based on the status and / or information of the AC / DC power main circuit and the status and / or information of the AC / AC power main circuit.

[0029] The first driving circuit may be configured to drive the AC / AC power main circuit based on a first control command.

[0030] In the present application, the first control module can not only drive the switching tube in the AC / AC power main circuit based on the status and / or information of the AC / DC power main circuit and the status and / or information of the AC / AC power main circuit, but also transmit the status and / or information of the AC / AC power main circuit to the second control module, thereby providing a basis for the second control module to reliably drive the switching tube in the AC / DC power main circuit.

[0031] In another example, the second control module may include a second detection circuit, a second communication circuit, a second control circuit, and a second driving circuit.

[0032] Optionally, the input end of the second detection circuit can be coupled to the AC / DC power main circuit, the output end of the second detection circuit can be coupled to the input end of the second control circuit, the output end of the second control circuit can be coupled to the input end of the second drive circuit, the output end of the second drive circuit can be coupled to the AC / DC power main circuit, the second control circuit is also coupled to the second communication circuit, and the second communication circuit is coupled to the first communication circuit.

[0033] Based on the above coupling relationship, we can further determine:

[0034] The second detection circuit can be used to detect the status and / or information of the AC / DC power main circuit.

[0035] The second control circuit may be configured to transmit a status and / or information of the AC / DC power main circuit to the second communication circuit.

[0036] The second communication circuit may be configured to transmit the status and / or information of the AC / DC power main circuit to the first control module, and transmit the status and / or information of the AC / AC power main circuit from the first communication circuit to the second control circuit.

[0037] After the second communication circuit transmits the status and / or information of the AC / AC power main circuit and the status and / or information of the AC / DC power main circuit to the second control circuit, the second control circuit is further used to: send a second control command to the second drive circuit based on the status and / or information of the AC / AC power main circuit and the status and / or information of the AC / DC power main circuit (that is, at least one of the status of the AC / DC power main circuit, the information of the AC / DC power main circuit, the status of the AC / AC power main circuit, and the information of the AC / AC power main circuit).

[0038] The second driving circuit may be configured to drive the AC / DC power main circuit based on a second control command.

[0039] In the present application, the second control module can not only drive the switching tube in the AC / DC power main circuit based on the status and / or information of the AC / DC power main circuit and the status and / or information of the AC / AC power main circuit, but also transmit the status and / or information of the AC / DC power main circuit to the first control module, thereby providing a basis for the first control module to reliably drive the switching tube in the AC / AC power main circuit.

[0040] It is understandable that the first control module and the second control module need to communicate with each other, and that communication between the two is achieved through the first communication circuit and the second communication circuit. In addition, the first control circuit needs to issue the first control command to the first drive circuit based not only on the status and / or information of the AC / DC power main circuit detected by the second detection circuit, but also on the status and / or information of the AC / AC power main circuit detected by the first detection circuit of the first communication circuit.

[0041] Similar to the first control circuit, the second control circuit needs to issue the first control command to the first drive circuit based not only on the status and / or information of the AC / DC power main circuit detected by the second detection circuit, but also on the status and / or information of the AC / AC power main circuit detected by the first detection circuit of the first communication circuit.

[0042] That is to say, the first power circuit needs to control the switching tube in its own internal AC / AC power main circuit based on the state of the switching tube in its own internal AC / AC power main circuit and the information (voltage and or current) of the AC / AC power main circuit, as well as the state of the switching tube in the AC / DC power main circuit in the second power circuit and the information (voltage and or current) of the AC / DC power main circuit.

[0043] Similar to the first power circuit, the second power circuit needs to control the switching tube in its own internal AC / DC power main circuit based on the state of the switching tube in its own internal AC / DC power main circuit and the information (voltage and or current) of the AC / DC power main circuit, as well as the state of the switching tube in the AC / AC power main circuit in the first power circuit and the information (voltage and or current) of the AC / AC power main circuit.

[0044] In a possible implementation, the first auxiliary power supply circuit may include a first voltage conversion module and a first rectification module.

[0045] Optionally, the input end of the first voltage conversion module can be coupled to the bus of the power unit (one power unit includes a bus), the output end of the first voltage conversion module can be coupled to the input end of the first rectifier module, and the output end of the first rectifier module can be coupled to the first control module.

[0046] Based on the above coupling relationship, the first voltage conversion module can be configured to convert the voltage of the busbar of the power unit into a sixth voltage (which can be represented by V6) and output it to the first rectifier module. The sixth voltage V6 can be used to indicate the AC voltage output by the first voltage conversion module.

[0047] Furthermore, the first rectifier module may be configured to rectify the sixth voltage V6 into a third voltage V3 and output the third voltage V3 to the first control module, thereby providing power to the first control module.

[0048] It is understandable that, because the input of the power unit is medium voltage (AC power) and the output of the power unit is low voltage (DC power), and because the input end of the first auxiliary power supply circuit is coupled to the bus of the corresponding power unit, the first auxiliary power supply circuit can be referred to as a medium voltage auxiliary power supply circuit. Furthermore, because the first auxiliary power supply circuit supplies power to the first control module based on the voltage of the bus of the power unit, the first control module can also be referred to as a medium voltage control module.

[0049] The present application adjusts the bus voltage of the power unit to the voltage required by the first control module through the first voltage conversion module and the first rectifier module, thereby achieving reliable power supply for the first control module without the need to set up other separate isolation devices, thereby reducing the power supply cost of the first control module. Since the first auxiliary power supply circuit is located inside the power unit, the volume of the power unit is also reduced.

[0050] In a second aspect, the present application also provides a solid-state transformer, which may include a second auxiliary power supply circuit and a plurality of the above-mentioned power units.

[0051] Optionally, the input end of each of the plurality of power units is connected in series to form the input end of the solid-state transformer, and the output end of each of the plurality of power units is connected in parallel to form the output end of the solid-state transformer.

[0052] The input end of the second auxiliary power supply circuit can be coupled to the output end of the AC / DC power main circuit, and the output end of the second auxiliary power supply circuit is coupled to the second control module.

[0053] Based on the above coupling relationship, the second auxiliary power supply circuit can be configured to adjust the fifth voltage V5 to a seventh voltage (which can be represented by V7) and output it to the second control module (i.e., to power the second control module). The seventh voltage V7 can be used to indicate the DC voltage required by the second control module.

[0054] It should be noted that, since each power unit includes a first auxiliary power supply circuit, the number of first auxiliary power supply circuits is equal to the number of power units and the number of first control modules. Furthermore, since the input end of the first auxiliary power supply circuit in each power unit is coupled to the busbar of the corresponding power unit, and the output end of the first auxiliary power supply circuit in each power unit is coupled to the corresponding first control module, the first auxiliary power supply circuit has a distributed structure for the solid-state transformer.

[0055] It should also be noted that the second auxiliary power supply circuit supplies power to each second control module in the plurality of power units, so for the solid-state transformer, the second auxiliary power supply circuit is a centralized structure.

[0056] The present application realizes reliable power supply of the second control module in the second power circuit through the second auxiliary power supply circuit, and realizes physical isolation between the centralized second auxiliary power supply circuit and the distributed first auxiliary power supply circuit. There is no need to set up additional isolation equipment for the first auxiliary power supply circuit and the second auxiliary power supply circuit, which reduces the cost of the solid-state transformer and reduces the size of the solid-state transformer.

[0057] In a possible implementation, the second auxiliary power supply circuit may include a second transformer and a first auxiliary power supply module.

[0058] Optionally, the input end of the second transformer can be coupled to the grid power supply system, the output end of the second transformer can be coupled to the input end of the first auxiliary power supply module, the input end of the first auxiliary power supply module can also be coupled to the output end of the AC / DC power main circuit, and the output end of the first auxiliary power supply module can be coupled to the second control module.

[0059] Based on the above coupling relationship, the second transformer can be configured to adjust the first voltage V1 to an eighth voltage (which can be represented by V8) and output it to the first auxiliary power module (i.e., to supply power to the first auxiliary power module). The eighth voltage V8 can be used to indicate the AC voltage required by the first auxiliary power module.

[0060] Furthermore, the first auxiliary power supply module may be configured to adjust the fifth voltage V5 and the eighth voltage V8 into a seventh voltage V7 and output it to the second control module (ie, to supply power to the second control module).

[0061] It should be noted that the first voltage V1 can be high voltage AC or medium voltage AC, and the eighth voltage V8 can be low voltage AC. Therefore, the voltage value of the first voltage can be greater than the voltage value of the second voltage. In other words, the second transformer performs a voltage step-down function, i.e., the first voltage V1 (high voltage or medium voltage) from the power grid can be stepped down to the eighth voltage V8 (low voltage) via the second transformer.

[0062] It will be appreciated that regardless of whether the second transformer converts high-voltage AC power from the power grid into low-voltage AC power or converts medium-voltage AC power from the power grid into low-voltage AC power, the second transformer performs a voltage reduction function. The first auxiliary power module supplies power to the second control module based on the low-voltage AC power converted by the second transformer. Therefore, the second control module can also be referred to as a low-voltage control module.

[0063] It should also be noted that since the input voltage of the power unit can be medium voltage (alternating current) and the output voltage of the power unit can be low voltage (direct current), and because the input ends of the first auxiliary power supply module and the second auxiliary power supply module are respectively coupled with the output ends of the corresponding AC / DC power main circuit, the first auxiliary power supply module and the second auxiliary power supply module can be called low-voltage auxiliary power supply modules.

[0064] Optionally, the second transformer may be an industrial frequency transformer. The industrial frequency transformer can obtain a first voltage V1 (e.g., a line voltage) from the power grid and adjust the first voltage V1 to an eighth voltage V8, which is then provided to the first auxiliary power module. The industrial frequency transformer has low power and size, is low-cost, and can improve the reliability of the power unit.

[0065] Of course, in addition to being an industrial frequency transformer, the second transformer can also be other types of transformers, which is not limited in the embodiments of the present application.

[0066] The present application realizes reliable power supply of the second control module through the second transformer and the first auxiliary power supply module, thereby realizing reliable driving of the switch tube in the AC / DC power main circuit, thereby improving the reliability of the power unit.

[0067] In a possible implementation, the power unit provided in the present application may further include a fan for dissipating heat for the power unit, and the second auxiliary power supply circuit may further include at least one second auxiliary power supply module.

[0068] Optionally, the input end of each second auxiliary power supply module of the at least one second auxiliary power supply module can be coupled to the output end of the AC / DC power main circuit, and the output end of each second auxiliary power supply module can be coupled to the fan.

[0069] Based on the above coupling relationship, each second auxiliary power supply module can be configured to adjust the fifth voltage V5 to a ninth voltage (which can be represented by V9) and output it to the fan (i.e., power the fan). The ninth voltage V9 can be used to indicate the voltage required by the fan.

[0070] It can be understood that the second auxiliary power supply circuit can supply power to the fan while supplying power to the second control module, so that the fan can stably dissipate heat for the power unit.

[0071] It is also understandable that the power required by the second control module is lower than the power required by the fan. Therefore, the power of the first auxiliary power module supplying power to the second control module is lower, while the power of the second auxiliary power module supplying power to the fan is higher. In other words, the power of the second auxiliary power module is greater than that of the first auxiliary power module.

[0072] Illustratively, the output power of the second transformer may be greater than the output power of the first auxiliary power module, and the output power of the first auxiliary power module may be less than the output power of each of the second auxiliary power modules. For example, the output power of the first auxiliary power module may be 200 W, the output power of the second transformer may be 500 W, and the output power of the second auxiliary power modules may be 500 W or 600 W.

[0073] In this embodiment of the present application, the lower-power first auxiliary power module supplies power to the lower-power second control module of the power unit, while the lower-power second auxiliary power module supplies power to the fan (higher power). In other words, the power supply requirements of the high-power fan and the lower-power second control module are independently met by the second auxiliary power module and the first auxiliary power module.

[0074] Since the output voltage of the solid-state transformer has multiple voltage values ​​such as 400V and 800V, the second auxiliary power supply circuit provided in the present application can achieve matching of the input voltage of the second auxiliary power supply circuit with the output voltage of the solid-state transformer through multiple (such as two) second auxiliary power supply modules. The second auxiliary power supply circuit can reliably provide auxiliary power to the power unit according to the different output voltages of the solid-state transformer (that is, the second auxiliary power supply circuit can power the second control module according to the different output voltages of the power unit), thereby improving the stability of the solid-state transformer. At the same time, at least one second auxiliary power supply module in the second auxiliary power supply circuit can adjust the output voltage of the AC / DC power main circuit to the voltage required by the fan, that is, by realizing the power supply of the fan, the fan can stably dissipate heat for the power unit.

[0075] In an example, the input voltage of the first auxiliary power module may be 114V to 840V. The input voltage of the second auxiliary power module may be 400V.

[0076] In another example, when the second auxiliary power supply circuit includes a first auxiliary power supply circuit and two second auxiliary power supply modules, not only can the input voltage of the second auxiliary power supply circuit be achieved as 400V through the two second auxiliary power supply modules, but the input voltage of the second auxiliary power supply circuit can also be achieved as 800V through the two second auxiliary power supply modules.

[0077] It can be understood that the input of the second auxiliary power supply circuit in the present application (such as: the 800V wide range voltage composed of the 400V input voltages of the two second auxiliary power supply modules) and the output (such as the output voltage of the first auxiliary power supply module (that is, the DC voltage required by the second control module) and the output voltage of the second auxiliary power supply module (that is, the voltage required by the fan)) are divided into a wide voltage input range (that is, 800V voltage) and a small power requirement (corresponding to the second control module with smaller power) and a narrow voltage input range (that is, 400V voltage) and a large power requirement (corresponding to the fan with larger power). The second auxiliary power supply circuit can simultaneously power the second control module and the fan without the need to set up other power supplies and isolation equipment, which not only reduces the volume and cost of the second auxiliary power supply circuit, but also improves the reliability of the second auxiliary power supply circuit. Moreover, as long as the second auxiliary power supply circuit is connected to the power grid power supply system, the second control module can be powered by the second transformer and the first auxiliary power supply module, thereby expanding the scope of application of the second auxiliary power supply circuit.

[0078] In a possible implementation, each of the at least one second auxiliary power supply module may include a power factor correction module and a resonance module.

[0079] Optionally, the input end of the power factor correction module is coupled to the output end of the AC / DC power main circuit, the output end of the power factor correction module can be coupled to the input end of the resonance module, and the output end of the resonance module can be coupled to the fan.

[0080] Based on the above coupling relationship, the power factor correction module can be configured to: adjust the fifth voltage V5 to a tenth voltage (which can be expressed as V 10 denoted by ). Wherein, the tenth voltage V 10 Used to indicate the voltage required by the resonant module.

[0081] Furthermore, the resonance module can be configured to: 10 The voltage is converted into a ninth voltage V9 and output to the fan.

[0082] In a possible implementation, the first auxiliary power supply module may include a second rectifier module, a backflow prevention module, a second voltage conversion module, and a third rectifier module.

[0083] Optionally, the input end of the anti-backflow module can be coupled with the output end of the AC / DC power main circuit, the output end of the anti-backflow module can be coupled with the input end of the second rectifier module, the input end of the second rectifier module can also be coupled with the output end of the second transformer, the output end of the second rectifier module can be coupled with the input end of the second voltage conversion module, the output end of the second voltage conversion module can be coupled with the input end of the third rectifier module, and the output end of the third rectifier module can be coupled with the second control module (here it can be considered that the output end of the third rectifier module is coupled with the second detection circuit in the second control module).

[0084] Based on the above coupling relationship, the second rectifier module can be configured to: transform the fifth voltage V5 and the eighth voltage V8 into an eleventh voltage (which can be represented by V 11 ) and output to the second voltage conversion module. 11 It can be used to indicate the DC voltage output by the first rectifier module.

[0085] Furthermore, the anti-backflow module can be configured to: prevent the eleventh voltage V 11 Backflow to the AC / DC power main circuit.

[0086] Furthermore, the second voltage conversion module can be configured to: convert the eleventh voltage V 11 Processed into the twelfth voltage (can be used V 12 ) is output to the third rectifier module. 12 It can be used to indicate the AC voltage output by the second voltage conversion module.

[0087] Furthermore, the third rectifier module can be configured to: convert the twelfth voltage V 12 The seventh voltage V7 is converted into the seventh voltage and output to the second control module.

[0088] In a possible implementation, the aforementioned backflow prevention module may include a first switch tube (which plays a role in backflow prevention).

[0089] Exemplarily, the first switching transistor may be a diode, a triode, or a field effect transistor (which may be a junction field effect transistor or an insulated gate field effect transistor).

[0090] For example, when the first switching tube is a diode, the anode of the diode can be coupled to the output end of the AC / DC power main circuit, and the cathode of the diode can be coupled to the input end of the second rectifier module.

[0091] For another example, when the first switching tube is a transistor, the collector of the transistor can be coupled to the output end of the AC / DC power main circuit, and the emitter of the transistor can be coupled to the input end of the second rectifier module.

[0092] For another example, when the first switching tube is a field effect tube, the source of the field effect tube can be coupled to the output end of the AC / DC power main circuit, and the drain of the field effect tube can be coupled to the input end of the second rectifier module.

[0093] In one possible implementation, the first auxiliary power supply module can be redundant with the first auxiliary power supply module (low-voltage auxiliary power supply module) of the auxiliary power supply system in other solid-state transformers (it can also be said to be a backup for each other). When the transformer system includes only a single solid-state transformer (the solid-state transformer can include two second auxiliary power supply modules), the failure of any second auxiliary power supply module will not cause the second auxiliary power supply circuit to shut down, and the failed second auxiliary power supply module can be quickly replaced, thereby improving the stability of the second auxiliary power supply circuit and thus achieving reliable operation of the solid-state transformer. When the transformer system includes more than two solid-state transformers, the replacement of any second auxiliary power supply circuit will not cause the transformer system to shut down. The first auxiliary power supply module and the second auxiliary power supply module in the second auxiliary power supply circuit are respectively provided with hot-swap interfaces to support hot-swap. The second auxiliary power supply circuit provided in the present application can effectively improve the stability and maintenance speed of the transformer system.

[0094] It should be understood that the second aspect of this application is consistent with the technical solution of the first aspect of this application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation methods are similar, which will not be repeated. BRIEF DESCRIPTION OF THE DRAWINGS

[0095] Figure 1 The following is a schematic diagram showing the structure of the power unit PU in an embodiment of the present application;

[0096] Figure 2 The following is a schematic diagram showing the structure of the power unit PU in an embodiment of the present application;

[0097] Figure 3 It shows a schematic structural diagram of the first control module CM1 in an embodiment of the present application;

[0098] Figure 4 A schematic structural diagram of the second control module CM2 in an embodiment of the present application is shown;

[0099] Figure 5 The following is a schematic diagram showing the structure of the power unit PU in an embodiment of the present application;

[0100] Figure 6 The following is a schematic diagram showing the structure of a three-phase auxiliary power supply circuit of a power unit PU in an embodiment of the present application;

[0101] Figure 7 Schematic diagram of the structure of the first auxiliary power supply circuit A in an embodiment of the present application is shown;

[0102] Figure 8Schematic diagram of the structure of the first auxiliary power supply circuit A in an embodiment of the present application is shown;

[0103] Figure 9 Schematic diagram of the structure of the first auxiliary power supply circuit A in an embodiment of the present application is shown;

[0104] Figure 10 A schematic structural diagram of a solid-state transformer SST in an embodiment of the present application is shown;

[0105] Figure 11 A schematic structural diagram of a solid-state transformer SST in an embodiment of the present application is shown;

[0106] Figure 12 Schematic diagram of the structure of the second auxiliary power supply circuit B in an embodiment of the present application is shown;

[0107] Figure 13 Schematic diagram of the structure of the second auxiliary power supply circuit B in an embodiment of the present application is shown;

[0108] Figure 14 Schematic diagram of the structure of the second auxiliary power supply circuit B in an embodiment of the present application is shown;

[0109] Figure 15 A schematic structural diagram of the first auxiliary power supply module SSPM1 in an embodiment of the present application is shown;

[0110] Figure 16 A schematic structural diagram of the first auxiliary power supply module SSPM1 in an embodiment of the present application is shown;

[0111] Figure 17 A schematic structural diagram of the first auxiliary power supply module SSPM1 in an embodiment of the present application is shown;

[0112] Figure 18 A schematic structural diagram of the second auxiliary power supply module SSPM2 in an embodiment of the present application is shown;

[0113] Figure 19 A schematic structural diagram of the first auxiliary power supply module SSPM2 in an embodiment of the present application is shown;

[0114] Figure 20 A schematic structural diagram of the first auxiliary power supply module SSPM2 in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0115] The technical solution in this application will be described below with reference to the accompanying drawings.

[0116] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0117] The terms "first," "second," and the like in the description, embodiments, claims, and drawings of this application are used solely for descriptive purposes and are not to be construed as indicating or implying relative importance or order. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions, such as, for example, inclusion of a series of steps or units. A method, system, product, or apparatus is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0118] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0119] With the development of power systems, power transformers have become a key component of power systems such as power plants and substations. Power transformers not only increase voltage to deliver electricity to users, but also reduce it to various operating voltages to meet demand. In short, power transformers can perform both voltage step-up and step-down operations. The transmission of electrical energy in power systems inevitably results in losses in both voltage and power. For a given power output, voltage loss is inversely proportional to voltage, while power loss is inversely proportional to the square of voltage. Using power transformers not only increases voltage but also reduces transmission losses.

[0120] Power transformers include conventional transformers and solid-state transformers (SSTs). Conventional transformers consist of two or more coil windings wound on a common iron core. The windings are connected by an alternating magnetic field and operate according to the principle of electromagnetic induction. When a conventional transformer is running at no load, it requires a large amount of reactive power. This reactive power needs to be supplied by the power supply system. The rated capacity of a conventional transformer should be selected according to the needs of the power load and should not be too large or too small. Solid-state transformers (SSTs) are stationary electrical devices that combine power electronics conversion technology with high-frequency power conversion technology based on the principle of electromagnetic induction to convert electrical energy of one power characteristic into electrical energy of another power characteristic (such as voltage conversion and energy transfer).

[0121] Due to their reliable operation and simple structure, conventional transformers have become a vital component of power grid power supply systems and are widely used. The main functions of conventional transformers are voltage level conversion and electrical isolation. However, conventional transformers are large, cannot maintain a stable output voltage, and have no ability to improve power quality. Compared with conventional power transformers, solid-state transformers (SSTs) are smaller, can maintain a stable output voltage, and can improve the power factor and current harmonics on the input side. When applied to power systems, SSTs can improve power quality and stability, enable flexible transmission methods, and enable real-time control of power flows in power markets. Therefore, SSTs have become a major research topic in power systems.

[0122] Since the power unit in the solid-state transformer SST includes a control module for realizing functions such as controlling and driving the power devices in the power unit, how to provide power to the control module becomes an urgent problem to be solved.

[0123] In order to solve the above problems, the embodiment of the present application provides a power unit, such as Figure 1 Reference Figure 1 The power unit (PU) may include a first auxiliary power circuit A and a first power circuit PC 1. The first power circuit PC1 may include an AC / AC power main circuit and a first control module CM 1 coupled to the AC / AC power main circuit.

[0124] from Figure 1 It can be seen that the input end of the first auxiliary power supply circuit A is connected to the AC / AC power main circuit (which can be the bus of the AC / AC power main circuit, Figure 1The output end of the first auxiliary power supply circuit A is coupled to the first control module CM1; the AC / AC power main circuit includes an input end and an output end. The input end of the AC / AC power main circuit can be coupled to the power supply system (PS, which can be a distribution system or a transmission system) of the power grid, and the output end of the AC / AC power main circuit can be coupled to the transformer in the power unit (i.e., the first transformer T

[0125] (transformer)1) coupling.

[0126] exist Figure 1 In terms of the coupling relationship shown, the AC / AC power main circuit can be configured to adjust the first voltage V1 from the grid power supply system PS to a second voltage V2 and output it through the output end of the AC / AC power main circuit (which can be output to the first transformer T1).

[0127] Furthermore, the first control module CM1 can be configured to: detect the state of the AC / AC power main circuit and / or information of the AC / AC power main circuit, and drive the AC / AC power main circuit (can drive the switching tube in the AC / AC power main circuit) according to the state and / or information of the AC / AC power main circuit.

[0128] Furthermore, the first auxiliary power supply circuit A can be configured to: convert the voltage V of the bus of the AC / AC power main circuit bus The third voltage V3 is adjusted to a third voltage V3 and output to the first control module CM1 (ie, the first auxiliary power circuit A supplies power to the first control module CM1). The third voltage V3 can be used to indicate the DC voltage required by the first control module CM1.

[0129] It should be noted that the state of the AC / AC power main circuit may be the state (including on and off) of a switch (such as a transistor or an IGBT) in the AC / AC power main circuit. The information of the AC / AC power main circuit may include the input voltage, input current, output voltage, and / or output current of the AC / AC power main circuit.

[0130] Since the first voltage V1 is typically an AC voltage, i.e., the input of the first power circuit PC1 is typically AC power, and the output of the first power circuit PC1 is also AC power, the first power circuit PC1 can be referred to as an AC conversion circuit. Furthermore, since the input of the first power circuit PC1 is typically high voltage or medium voltage, the first power circuit PC1 can also be referred to as a high voltage power circuit or a medium voltage power circuit.

[0131] The power unit PU provided in the embodiments of the present application can reliably power the first control module CM1 in the first power circuit PC1 via the first auxiliary power circuit A, thereby improving the operational reliability of the first control module CM1. Furthermore, the power unit PU eliminates the need for separate isolation equipment, reduces the power supply cost for the first control module CM1, and reduces the size of the power unit PU.

[0132] exist Figure 1 Based on this, the embodiments of the present application provide Figure 2 The power unit PU is shown. Figure 2 The power unit PU may further include a first transformer T(1) and a second power circuit PC2. The second power circuit PC2 may include an AC / DC power main circuit and a second control module CM2 coupled to the AC / DC power main circuit. The AC / DC power main circuit may include an input terminal and an output terminal.

[0133] Optionally, the input end of the first transformer T1 is coupled to the output end of the AC / AC power main circuit, and the output end of the first transformer T1 is coupled to the input end of the AC / DC power main circuit.

[0134] exist Figure 2 Based on the coupling relationship shown, the first transformer T1 can be configured to adjust the second voltage V2 to a fourth voltage V4 and output it to the AC / DC power main circuit. The fourth voltage V4 can be used to indicate the AC voltage required by the AC / DC power main circuit.

[0135] Furthermore, the AC / DC power main circuit is configured to rectify the fourth voltage V4 into a fifth voltage V5 and output it through an output terminal of the AC / DC power main circuit (which may be output to the second auxiliary power supply circuit B). The fifth voltage V5 may be used to indicate the DC voltage output by the AC / DC power main circuit.

[0136] Furthermore, the second control module CM2 may be configured to detect a state and / or information of the AC / DC power main circuit, and drive the AC / DC power main circuit based on the state and / or information of the AC / DC power main circuit.

[0137] Optionally, the first transformer T1 may be a high-frequency transformer or other types of transformers, which is not limited in the embodiment of the present application.

[0138] For example, the state of the AC / DC power main circuit may be the state (including on and off) of a switch (such as a transistor or an IGBT) in the AC / DC power main circuit. The information of the AC / DC power main circuit may include the input voltage, input current, output voltage, and / or output current of the AC / DC power main circuit.

[0139] It should be noted that the voltage value (also known as the voltage level) of the first power circuit PC1 can be higher than the voltage value of the second power circuit PC2. Since the input of the first power circuit PC1 is typically AC power from the power grid power supply system PS, and the output of the first power circuit PC1 is also AC power, the first power circuit PC1 can be referred to as an AC conversion circuit. In addition, the input of the first power circuit PC1 is typically high voltage (e.g., a voltage greater than 35 kV and less than 220 kV) or medium voltage (e.g., a voltage greater than 1 kV and less than 35 kV), so the first power circuit PC1 can also be referred to as a high-voltage power circuit or a medium-voltage power circuit.

[0140] It should also be noted that since the output of the first power circuit PC1 (i.e., the output of the AC / AC power main circuit within the first power circuit PC1) is coupled to the input of the first transformer T1 (i.e., the primary winding of the first transformer T1), and the output of the first transformer T1 (i.e., the secondary winding of the first transformer T1) is coupled to the input of the second power circuit PC2 (i.e., the input of the AC / DC power main circuit within the second power circuit PC2), it can be determined that the first transformer T1 converts the high or medium voltage from the first power circuit PC1 into a low voltage (e.g., a voltage below 1 kV, also referred to as an AC voltage). Furthermore, the second power circuit PC2 converts the low voltage converted by the first transformer T1 into a DC voltage (this DC voltage is also referred to as a low voltage). Therefore, the second power circuit PC2 can be referred to as a low-voltage power circuit.

[0141] The embodiment of the present application implements the conversion and transmission from the input to the output of the power unit through the AC / AC power main circuit, the first transformer T1, and the AC / DC power main circuit. At the same time, the first control module CM1 is used to implement the reliable driving of the switch tube in the AC / AC power main circuit, and the second control module CM2 is used to implement the reliable driving of the switch tube in the AC / DC power main circuit, thereby improving the reliability of the AC / DC power main circuit and the AC / AC power main circuit.

[0142] In one example, Figure 2 The first control module CM1 in the embodiment can be further described as follows Figure 3 Reference Figure 3 The first control module CM1 may include a first detection circuit 11 , a first communication circuit 12 , a first control circuit 13 and a first driving circuit 14 .

[0143] Optionally, the input end of the above-mentioned first detection circuit 11 can be coupled to the AC / AC power main circuit, the output end of the first detection circuit 11 can be coupled to the input end of the first control circuit 13, the output end of the first control circuit 13 can be coupled to the input end of the first drive circuit 14, the output end of the first drive circuit 14 can be coupled to the AC / AC power main circuit, the first control circuit 13 is also coupled to the first communication circuit 12, and the first communication circuit 12 is coupled to the second control module CM2 (which can be the second communication circuit 22 of the second control module CM2).

[0144] exist Figure 3 Based on the coupling relationship shown, it can be further determined that:

[0145] The first detection circuit 11 can be used to detect the status and / or information of the AC / AC power main circuit.

[0146] Furthermore, the state of the AC / DC power main circuit may include the state of the power switch tube in the AC / DC power main circuit (including the on state and the off state), and the information of the AC / DC power main circuit may include the current and voltage of the AC / DC power main circuit.

[0147] For example, a current transformer may be used to collect the current (input current and output current) of the AC / DC power main circuit, and a resistor voltage divider circuit may be used to collect the voltage (input voltage and output voltage) of the AC / DC power main circuit.

[0148] The first control circuit 13 may be configured to transmit a status and / or information of the AC / AC power main circuit to the first communication circuit 12 .

[0149] The first communication circuit 12 can be used to: transmit the status and / or information of the AC / AC power main circuit to the second control module CM2 (which can be the second communication circuit 22 of the second control module CM2), and transmit the status and / or information of the AC / AC power main circuit from the second control module CM2 (which can be the second communication circuit 22 of the second control module CM2) to the first control circuit 13.

[0150] It should be noted that, since the first power circuit PC1 includes the first control module CM1 and the AC / AC power main circuit (see above), and the second power circuit PC2 includes the second control module CM2 and the AC / DC power main circuit (see below), the first communication circuit 12 can transmit the status and / or information of the AC / AC power main circuit to the second control module CM2 (i.e., the second communication circuit 22 of the second control module CM2), and the second communication circuit 22 can transmit the status and / or information of the AC / DC power main circuit to the first control module CM1 (which can be the first communication circuit 12 of the first control module CM1).

[0151] After the first communication circuit 12 transmits the status and / or information of the AC / AC power main circuit and the status and / or information of the AC / DC power main circuit from the second communication circuit 22 (that is, at least one of the status of the AC / DC power main circuit, the information of the AC / DC power main circuit, the status of the AC / AC power main circuit, and the information of the AC / AC power main circuit) to the first control circuit 13, the first control circuit 13 can also be used to: perform a proportional-integral-derivative (PID) operation on the status and / or information of the AC / DC power main circuit and the status and / or information of the AC / AC power main circuit to obtain a first control command CC (control command) 1, and send the first control command CC1 to the first drive circuit 14.

[0152] The first control command CC1 may be a pulse width modulation wave (PWM wave), which may include a frequency and a duty cycle.

[0153] Optionally, the first control circuit 13 may determine the state of the switch in the AC / AC power main circuit by using the current and / or voltage of the AC / AC power main circuit detected by the first detection circuit 11 .

[0154] For example, if the current of the AC / AC power main circuit shows an upward trend, the first control circuit 13 can determine that the state of the power switch tube in the AC / AC power main circuit is the on state; conversely, if the current of the AC / AC power main circuit shows a downward trend, the first control circuit 13 can determine that the state of the power switch tube in the AC / AC power main circuit is the off state.

[0155] Furthermore, the first driving circuit 14 may be configured to drive the AC / AC power main circuit based on the first control command CC1 .

[0156] Optionally, the first drive circuit 14 can control the switching time (or on-time and off-time) of the power switch tube according to the frequency of the PWM wave and the duty cycle of the PWM wave, thereby realizing reliable driving of the AC / AC power main circuit and realizing the regulation of the voltage and current of the AC / AC power main circuit.

[0157] In the embodiment of the present application, the first control module CM1 can not only drive the switch tube in the AC / AC power main circuit based on the status and / or information of the AC / DC power main circuit and the status and / or information of the AC / AC power main circuit, but also transmit the status and / or information of the AC / AC power main circuit to the second control module CM2, thereby providing a basis for the second control module CM2 to reliably drive the switch tube in the AC / DC power main circuit.

[0158] In another example, Figure 2 The second control module CM2 in the embodiment can be further configured as follows: Figure 4 Reference Figure 4 The second control module CM2 may include a second detection circuit 21 , a second communication circuit 22 , a second control circuit 23 and a second driving circuit 24 .

[0159] Optionally, the input end of the second detection circuit 21 can be coupled to the AC / DC power main circuit, the output end of the second detection circuit 21 can be coupled to the input end of the second control circuit 23, the output end of the second control circuit 23 can be coupled to the input end of the second drive circuit 24, the output end of the second drive circuit 24 can be coupled to the AC / DC power main circuit, the second control circuit 23 is also coupled to the second communication circuit 22, and the second communication circuit 22 is coupled to the first communication circuit 11 of the first control module CM1.

[0160] exist Figure 4 Based on the coupling relationship shown, it can be further determined that:

[0161] The second detection circuit 21 can be used to detect the status and / or information of the AC / DC power main circuit.

[0162] Furthermore, the state of the AC / DC power main circuit may include the state of the power switch tube in the AC / DC power main circuit (including the on state and the off state), and the information of the AC / DC power main circuit may include the current and voltage of the AC / AC power main circuit.

[0163] For example, a current transformer may be used to collect the current (input current and output current) of the AC / DC power main circuit, and a resistor voltage divider circuit may be used to collect the voltage (input voltage and output voltage) of the AC / DC power main circuit.

[0164] The second control circuit 23 may be configured to transmit the status and / or information of the AC / DC power main circuit to the second communication circuit SC22 .

[0165] The second communication circuit 22 can be used to transmit the status and / or information of the AC / DC power main circuit to the first communication circuit 12 , and transmit the status and / or information of the AC / AC power main circuit from the first communication circuit 12 to the second control circuit 23 .

[0166] After the second communication circuit 22 transmits the status and / or information of the AC / DC power main circuit and the status and / or information of the AC / AC power main circuit from the first communication circuit 12 (that is, at least one of the status of the AC / DC power main circuit, the information of the AC / DC power main circuit, the status of the AC / AC power main circuit, and the information of the AC / AC power main circuit) to the second control circuit 23, the second control circuit 23 can also be used to: perform PID operation on the status and / or information of the AC / DC power main circuit and the status and / or information of the AC / AC power main circuit from the first communication circuit 12 to obtain a second control command CC2, and send the second control command CC2 to the second drive circuit 24.

[0167] Similar to the first control command CC1, the second control command CC2 may also be a PWM wave, which may include a frequency and a duty cycle.

[0168] Optionally, the second control circuit 23 may determine the state of the switch in the AC / DC power main circuit by using the current and / or voltage of the AC / DC power main circuit detected by the second detection circuit 21 .

[0169] For example, if the current of the AC / DC power main circuit shows an upward trend, the second control circuit 23 can determine that the state of the power switch tube in the AC / DC power main circuit is the on state; on the contrary, if the current of the AC / DC power main circuit shows a downward trend, the second control circuit 23 can determine that the state of the power switch tube in the AC / DC power main circuit is the off state.

[0170] Furthermore, the second driving circuit 24 may be configured to drive the AC / DC power main circuit based on the second control command CC2 .

[0171] Optionally, the second drive circuit 24 can control the switching time (or on-time and off-time) of the power switch tube according to the frequency of the PWM wave and the duty cycle of the PWM wave, thereby realizing reliable driving of the AC / DC power main circuit and realizing the regulation of the voltage and current of the AC / DC power main circuit.

[0172] In the present application, the second control module CM2 can not only drive the switch tube in the AC / AC power main circuit based on the status and / or information of the AC / DC power main circuit and the status and / or information of the AC / AC power main circuit, but also transmit the status and / or information of the AC / DC power main circuit to the first control module CM1, thereby providing a basis for the first control module CM1 to reliably drive the switch tube in the AC / AC power main circuit.

[0173] from Figure 3 、 Figure 4 As can be understood from the above description, the first communication circuit 11 is coupled not only to the first control circuit 13 but also to the second communication circuit 22. Furthermore, the second communication circuit 22 is coupled not only to the second control circuit 23 but also to the first communication circuit 11. Thus, communication between the first control module CM1 and the second control module CM2 is achieved via the first communication circuit 11 and the second communication circuit 22. In other words, the status and / or information of the AC / AC power main circuit in the first power circuit PC1 and the status and / or information of the AC / DC power main circuit in the second power circuit PC2 can be transmitted between the first power circuit PC1 and the second power circuit PC2 via the first communication circuit 11 and the second communication circuit 22.

[0174] In addition, the first control circuit 13 needs to issue the first control command CC1 to the first drive circuit 14 based not only on the status and / or information of the AC / AC power main circuit detected by the first detection circuit 11, but also on the status and / or information of the AC / DC power main circuit detected by the second detection circuit 21.

[0175] Similar to the first control circuit 13, the second control circuit 23 needs to issue the second control command CC2 to the second drive circuit 24 based not only on the status and / or information of the AC / DC power main circuit detected by the second detection circuit 21, but also on the status and / or information of the AC / AC power main circuit detected by the first detection circuit 11.

[0176] That is, the first power circuit PC1 needs to control the operation of the switches in its internal AC / AC power main circuit based on the state of the switches in its internal AC / AC power main circuit and the information (voltage and / or current) of the AC / AC power main circuit, as well as the state of the switches in the second power circuit PC2 and the information (voltage and / or current) of the AC / DC power main circuit. Similar to the first power circuit PC1, the second power circuit PC2 needs to control the operation of the switches in its internal AC / DC power main circuit based on the state of the switches in its internal AC / DC power main circuit and the information (voltage and / or current) of the AC / DC power main circuit, as well as the state of the switches in the first power circuit PC1 and the information (voltage and / or current) of the AC / AC power main circuit.

[0177] Based on the above Figures 1 to 4 , we can get Figure 5 The power unit PU shown. Of course, Figure 5 This is only an exemplary structural diagram of the power unit PU. The power unit PU may also adopt other structural forms, which is not limited in the embodiments of the present application.

[0178] Since the input voltage of the power unit PU is usually three-phase AC, in a possible implementation, reference Figure 6 , the three-phase auxiliary power supply circuit of the power unit PU (i.e. Figure 6 Each phase of PACK A, PACK B and PACK C (ie PACK A, PACK B or PACK C, taking PACK A as an example) may include N first auxiliary power circuits A (ie Figure 6 The first auxiliary power supply circuit A1 to the first auxiliary power supply circuit AN in the embodiment. Figure 6 V in bus1 To V busN are the bus voltages of power unit PU1 to power unit PUN, V 31 To V 3N are the output voltages of the first auxiliary power supply circuit A1 to the first auxiliary power supply circuit AN, respectively.

[0179] It should be noted that N can be 1. When N is 1, it indicates that the solid-state transformer SST includes only one power unit. The input end of each of the N first auxiliary power circuits A is coupled to the bus of the corresponding power unit (the first power circuit PM1 in a power unit includes a bus), and the output end of each of the N first auxiliary power circuits A is coupled to the first control module CM1 (i.e., Figure 6There are N first control modules CM1 in total, from the first control module CM1-1 to the first control module CM1-N. It should be noted that one power unit includes one first control module CM1).

[0180] For example, an input end of the first auxiliary power supply circuit A1 is coupled to the busbar of the power unit PU1 , and an output end of the first auxiliary power supply circuit A1 is coupled to the first control module CM1 - 1 of the power unit PU1 .

[0181] For another example, an input end of the first auxiliary power supply circuit A2 is coupled to the busbar of the power unit PU2, and an output end of the first auxiliary power supply circuit A2 is coupled to the first control module CM1-2 of the power unit PU2.

[0182] For another example, the input end of the first auxiliary power circuit AN is coupled to the busbar of the power unit PUN, and the output end of the first auxiliary power circuit A1 is coupled to the first control module CM1 -N of the power unit PUN.

[0183] based on Figure 6 The coupling relationship can be determined that the first auxiliary power supply circuit A1 in the N first auxiliary power supply circuits A is based on the bus voltage V of the bus bus1 from the power unit. bus1 Power is supplied to the first control module CM1-1 of the power unit, that is, the first auxiliary power supply circuit A1 converts the bus voltage V bus1 Adjust to the voltage required by the first control module CM1-1 (ie Figure 6 The third voltage V 31 , which can also be considered as the output voltage of the first auxiliary power supply circuit A1) and outputs it to the first control module CM1-1 to power the first control module CM1-1. Similar to the first auxiliary power supply circuit A1, the first auxiliary power supply circuit A2 to the first auxiliary power supply circuit AN respectively receive the bus voltage V from bus2 to busN. bus2 To V busN Power is supplied to the first control module CM1-2 to the first control module CM1-N of the power unit, that is, the first auxiliary power circuit A2 to the first auxiliary power circuit AN respectively transmit the bus voltage V bus2 To V busN Adjust to the voltage required by the first control module CM1-1 to the first control module CM1-N (ie Figure 6 The third voltage V 32 To the third voltage V 3N , which can also be considered as the output voltages of the first auxiliary power circuit A2 to the first auxiliary power circuit AN respectively) and output to the first control module CM1-1 to the first control module CM1-N.

[0184] It is understandable that, because the input voltage of the power unit is medium voltage (AC power) and the output voltage of the power unit is low voltage (DC power), and because the input end of the first auxiliary power supply circuit A is coupled to the bus of the corresponding power unit, the first auxiliary power supply circuit A can be referred to as a medium-voltage auxiliary power supply circuit. Furthermore, because the first auxiliary power supply circuit A adjusts the bus voltage to the voltage required by the first control module CM1 and provides it to the first control module CM1, thereby powering the first control module CM1, the first control module CM1 can also be referred to as a medium-voltage control module.

[0185] In addition, if Figure 6 As shown, PACK A, PACK B, and PACK C are each equipped with a power board (PB, also called a control board). The power board PB is equipped with a third control module CM3 (also called a PACK control module, which is used to implement detection, control, drive, and communication of the power main circuits (including the AC / DC power main circuit and the AC / AC power main circuit) of each of PACK A, PACK B, and PACK C) and fan 1 (used to dissipate heat from the AC / DC power main circuit and the AC / AC power main circuit).

[0186] Furthermore, the first auxiliary power supply circuit A may include a first voltage conversion module 31 and a first rectifier module 32, such as Figure 7 As shown. Among them, the input end of the first voltage conversion module 31 is connected to the busbar of the power unit ( Figure 7 The output end of the first voltage conversion module 31 is coupled to the input end of the first rectifier module 32, and the output end of the first rectifier module 31 is coupled to the first control module CM1.

[0187] Based on the above coupling relationship, it can be further determined that the first voltage conversion module 31 converts the bus voltage (AC voltage, i.e. Figure 7 V in bus , which can be V bus1 To V busN The first rectifier module 32 rectifies the converted voltage from the first voltage conversion module 31 to obtain the DC voltage required by the first control module CM1 (i.e. Figure 7 V3 in the figure can also be considered as the output voltage of the first auxiliary power supply circuit A), and the third voltage V3 is provided to the first control module CM1.

[0188] In one possible implementation, the first auxiliary power supply circuit A may adopt the following two topologies:

[0189] Structure 1: Figure 8As shown, the second conversion module 31 includes a third transformer T3 (including a primary winding T31, a primary winding T32, an iron core and a secondary winding T33, the primary winding T31 and the primary winding T32 are coupled to the secondary winding T33 through the iron core), a sixth switch tube ( Figure 8 Take the N-type metal-oxide-semiconductor transistor (NMOS tube) as an example, that is, Figure 8 NMOS8) and the seventh switch tube ( Figure 8 Take NMOS tube as an example, that is Figure 8 The first rectifier module 32 includes a rectifier tube (which plays a rectifying role, Figure 8 Taking diode D9 as an example) and capacitor C8 (plays the role of filtering and energy storage).

[0190] Further, refer to Figure 8 , capacitor C6 and capacitor C7 are both bus capacitors. The two ends of capacitor C6 are coupled to node K (node ​​K is also coupled to the positive terminal bus+ of the bus) and node L respectively, and the two ends of capacitor C7 are coupled to node M (node ​​M is also coupled to the negative terminal bus- of the bus. The voltage between the positive terminal bus+ and the negative terminal bus- is the bus voltage V bus , which can also be called the input voltage of the first auxiliary power supply circuit A) is coupled with node L, that is, capacitor C6 and capacitor C7 are coupled through node L. The like-name end of the primary winding T31 is coupled with node K, the opposite-name end of the primary winding T31 is coupled with the drain of NMOS8, and the source of NMOS8 is coupled with node N (node ​​N is also coupled with node L). The like-name end of the primary winding T32 is coupled with node N, the opposite-name end of the primary winding T32 is coupled with the drain of NMOS9, and the source of NMOS9 is coupled with node M. The opposite-name end of the secondary winding T33 is coupled with the anode of the diode D9, and the like-name end of the secondary winding T33 is coupled with node P. The cathode of the diode D9 and one end of the capacitor C8 are both coupled with node O, and the other end of the capacitor C8 is coupled with node P (the voltage between node P and node O is the output voltage of the first auxiliary power supply circuit A, that is, the third voltage V3). It can be achieved through Figure 8 The first auxiliary power supply circuit A shown in FIG. 1 obtains a third voltage V3, and the first auxiliary power supply circuit A provides the third voltage V3 to the first control module CM1 ( Figure 8 not shown).

[0191] In another possible implementation, the sixth switching tube and the seventh switching tube in the first voltage conversion module 31 may also be IGBTs.

[0192] Optionally, when the sixth switch tube is an IGBT, the collector of the IGBT is coupled to the opposite-name end of the primary winding T31 , and the emitter of the IGBT is coupled to the node N.

[0193] Optionally, when the seventh switch tube is an IGBT, the collector of the IGBT is coupled to the opposite-name end of the primary winding T32, and the emitter of the IGBT is coupled to the node M.

[0194] In another possible implementation, the rectifier tube in the first rectifier module 32 may also be a field effect tube (which may be a junction field effect tube or an insulated gate field effect tube, taking an NMOS tube as an example). When the rectifier tube is an NMOS tube, the source of the NMOS tube is coupled to the opposite-name terminal of the secondary winding T33, and the drain of the NMOS tube is coupled to the node O.

[0195] Structure 2: Figure 9 As shown, the first voltage conversion module 31 includes a third transformer T3 (including a primary winding T31, a primary winding T32, an iron core and a secondary winding T33, the primary winding T31 and the primary winding T32 are coupled to the secondary winding T33 through the iron core), a sixth switch tube ( Figure 9 Take NMOS tube as an example, that is Figure 9 NMOS8) and the seventh switch tube ( Figure 9 Take NMOS tube as an example, that is Figure 9 The first rectifier module 32 includes a diode D9, a diode D10, an inductor L4 and a capacitor C8.

[0196] Further, refer to Figure 9 , capacitor C6 and capacitor C7 are both bus capacitors. The two ends of capacitor C6 are coupled to node K (node ​​K is also coupled to the positive terminal bus+ of the bus) and node L respectively, and the two ends of capacitor C7 are coupled to node M (node ​​M is also coupled to the negative terminal bus- of the bus. The voltage between the positive terminal bus+ and the negative terminal bus- is the bus voltage V bus , which may also be called the input voltage of the first auxiliary power supply circuit A) is coupled to node L, that is, capacitors C6 and C7 are coupled via node L. The same-name terminal of the primary winding T31 is coupled to node K, the opposite-name terminal of the primary winding T31 is coupled to the drain of NMOS 8, and the source of NMOS 8 is coupled to node N (node ​​N is also coupled to node L). The same-name terminal of the primary winding T32 is coupled to node N, the opposite-name terminal of the primary winding T32 is coupled to the drain of NMOS 9, and the source of NMOS 9 is coupled to node M. The opposite-name terminal of the secondary winding T33 is coupled to the anode of diode D9, and the same-name terminal of the secondary winding T33 is coupled to node P. The cathode of diode D9, one end of inductor L4, and the cathode of diode D10 are all coupled to node Q, the other end of inductor L4 and one end of capacitor C8 are all coupled to node O, and the other end of capacitor C8 and the anode of diode D10 are all coupled to node P (the voltage between node P and node O is the output voltage of the first auxiliary power supply circuit A, that is, the third voltage V3). Figure 9 The first auxiliary power supply circuit A shown in FIG. 1 obtains a third voltage V3, and the first auxiliary power supply circuit A provides the third voltage V3 to the first control module CM1 ( Figure 9 not shown).

[0197] In a possible implementation, the sixth switch tube and the seventh switch tube in the first voltage conversion module 31 may also be IGBTs.

[0198] Optionally, when the sixth switch tube is an IGBT, the collector of the IGBT is coupled to the opposite-name end of the primary winding T31 , and the emitter of the IGBT is coupled to the node N.

[0199] Optionally, when the seventh switch tube is an IGBT, the collector of the IGBT is coupled to the opposite-name end of the primary winding T32, and the emitter of the IGBT is coupled to the node M.

[0200] It should be noted that Figure 8 and Figure 9 Only two possible topologies of the first auxiliary power supply circuit are provided. Of course, the first voltage conversion module 31 may also adopt other topologies, which is not limited in the embodiment of the present application.

[0201] In the embodiment of the present application, the bus voltage of the power unit PU is adjusted to the voltage required by the first control module CM1 through the first voltage conversion module 31 and the first rectifier module 32, thereby achieving reliable power supply for the first control module CM1 without the need to set up other separate isolation devices, thereby reducing the power supply cost of the first control module CM1. Since the first auxiliary power supply circuit A is located inside the power unit, the volume of the power unit PU is also reduced.

[0202] The embodiment of the present application also provides a method comprising Figure 5 The solid-state transformer SST of the power unit shown is Figure 10 shown. Figure 10 V in in Represents the input voltage of the solid-state transformer SST (usually AC voltage), V out The solid-state transformer SST may include a second auxiliary power supply circuit B and N power units (i.e. Figure 10 The input terminals of the power units PU1, PU2, ..., and PUN are connected in series to form the input terminal of the solid-state transformer SST. The output terminals of the power units PU1, PU2, ..., and PUN are connected in parallel to form the output terminal of the solid-state transformer SST.

[0203] from Figure 10It can be seen that the input end of the second auxiliary power supply circuit B is coupled to the output end of the AC / DC power main circuit in each power unit PU, and the output end of the second auxiliary power supply circuit B is coupled to the second control module CM2.

[0204] It should be noted that Figure 10 FIG2 shows that the input end of the second auxiliary power supply circuit B is coupled to the output end of the AC / DC power main circuit in the power unit PU1, and the output end of the second auxiliary power supply circuit B is coupled to the second control module CM2 in the power unit PU1. The coupling relationship between the second auxiliary power supply circuit B and the AC / DC power main circuit and the second control module CM2 of other power units (i.e., power unit PU2 to power unit PUN) in the solid-state transformer SST is similar to FIG2. Figure 10 The coupling relationship shown in is the same, and the embodiments of the present application will not be described here.

[0205] exist Figure 10 Based on the above coupling relationship, the second auxiliary power supply circuit B can be configured to adjust the fifth voltage V5 (i.e., the DC voltage output by the AC / DC power main circuit) into a seventh voltage V7 and output it to the second control module CM2. The seventh voltage V7 can be used to indicate the DC voltage required by the second control module CM2 (which can also be considered the output voltage of the second auxiliary power supply circuit B).

[0206] In the embodiment of the present application, reliable power supply of the second control module CM2 in the second power circuit PC2 is achieved through the second auxiliary power supply circuit B, and physical isolation is achieved between the centralized second auxiliary power supply circuit B and the distributed first auxiliary power supply circuit A. There is no need to set up additional isolation equipment for the first auxiliary power supply circuit A and the second auxiliary power supply circuit B, thereby reducing the cost of the solid-state transformer SST and reducing the volume of the solid-state transformer SST.

[0207] like Figure 11 As shown, Figure 10 AC / AC power main circuit in Figure 11 The AC / AC power main circuit in the power supply unit may include a third AC / DC converter, a first DC / AC converter, and a second DC / AC converter. The first transformer T1 may include a high-frequency transformer T11 and a high-frequency transformer T12. Figure 10 The AC / DC power main circuit in Figure 11 The AC / DC power main circuit in the embodiment includes a first AC / DC converter and a second AC / DC converter.

[0208] Furthermore, the input terminal of the third AC / DC converter is connected to the power grid power supply system PS (embodied in Figure 11The output end of the third AC / DC converter is coupled through the bus (the bus is provided with a bus capacitor, i.e. Figure 11 The bus capacitor C11 and bus capacitor C12 in the first DC / AC converter are coupled to the input end of the first DC / AC converter and the input end of the second DC / AC converter. The output end of the first DC / AC converter is coupled to the primary winding of the high-frequency transformer T11 (i.e. Figure 11 The winding of the medium and high frequency transformer T11 close to the first DC / AC converter) is coupled, and the secondary winding of the high frequency transformer T11 (ie Figure 11 The winding of the medium / high frequency transformer T11 close to the first AC / DC converter is coupled to the input of the first AC / DC converter. Similarly, the output of the second DC / AC converter is coupled to the primary winding of the high frequency transformer T12 ( Figure 11 The secondary winding of the high frequency transformer T12 ( Figure 11 The winding of the medium / high frequency transformer T12 close to the second AC / DC converter is coupled to the input end of the second AC / DC converter.

[0209] It should be noted that Figure 11The positive DC terminal DC11+ and the negative DC terminal DC11- are the output terminals of the first AC / DC converter (i.e., the first AC / DC converter) in power unit PU1, and the positive DC terminal DC12+ and the negative DC terminal DC12- are the output terminals of the second AC / DC converter (i.e., the second AC / DC converter) in power unit PU1. The positive DC terminal DC21+ and the negative DC terminal DC21- are the output terminals of the first AC / DC converter in power unit PU2, and the positive DC terminal DC22+ and the negative DC terminal DC22- are the output terminals of the second AC / DC converter in power unit PU2. The positive DC terminal DCN1+ and the negative DC terminal DCN1- are the output terminals of the first AC / DC converter in power unit PUN, and the positive DC terminal DCN2+ and the negative DC terminal DCN2- are the output terminals of the second AC / DC converter in power unit PUN. Since the output terminals of the N power units are connected in parallel, the power unit PU1 is coupled to the positive DC terminal of the first AC / DC converter of each power unit PUN (i.e., the positive DC terminal DC11+ is coupled to the positive DC terminal DCN1+), and the power unit PU1 is coupled to the negative DC terminal of the first AC / DC converter of each power unit PUN (i.e., the negative DC terminal DC11- is coupled to the negative DC terminal DCN1-). Moreover, the power unit PU1 is coupled to the positive DC terminal of the second AC / DC converter of each power unit PUN (i.e., the positive DC terminal DC12+ is coupled to the positive DC terminal DCN2+), and the power unit PU1 is coupled to the negative DC terminal of the second AC / DC converter of each power unit PUN (i.e., the negative DC terminal DC12- is coupled to the negative DC terminal DCN2-). At the same time, multiple output terminals of the solid-state transformer SST are formed (e.g., Figure 11 The positive DC terminal DC1+, the negative DC terminal DC1-, the positive DC terminal DC2+, and the negative DC terminal DC2-).

[0210] from Figure 10 and Figure 11 It can be seen that the embodiment of the present application supplies power to the first control module CM1 through the first auxiliary power supply circuit A, and supplies power to the second control module CM2 through the second auxiliary power supply circuit B. The first auxiliary power supply circuit A is located inside the power unit PU, and physical isolation is achieved between the first auxiliary power supply circuit A and the second auxiliary power supply circuit B, thereby reducing the power supply cost of the first control module CM1 and the second control module CM2 in the solid-state transformer.

[0211] In one possible implementation, Figure 12 As shown, the second auxiliary power supply circuit B may include a second transformer T2 and a first auxiliary power supply module SSPM (subsidiary power supply module) 1.

[0212] from Figure 12As can be seen, the input of the second transformer T2 is coupled to the power grid PS, and the output of the second transformer T2 is coupled to the input of the first auxiliary power module SSPM1. The input of the first auxiliary power module SSPM1 is also coupled to the output of the AC / DC power main circuit of the power unit. The output of the first auxiliary power module SSPM1 is coupled to the second control module CM2 of the power unit.

[0213] Based on the above coupling relationship, it can be further determined that the second transformer T2 can be configured to adjust the first voltage V1 from the power grid system PS to an eighth voltage V8 (i.e., the AC voltage required by the first auxiliary power supply module SSPM1; the eighth voltage V8 is an AC voltage and can range from 144V to 264V) and output it to the auxiliary power supply module SSPM1. It should be noted that the voltage value of the first voltage V1 is greater than the voltage value of the eighth voltage V8. In other words, the second transformer T2 performs a voltage step-down function, i.e., the second transformer T2 can reduce the first voltage V1 from the power grid system to the second voltage V8.

[0214] It can also be determined that the first auxiliary power supply module SSPM1 can be configured to: adjust the eighth voltage V8 and the fifth voltage V5 from the AC / DC power main circuit into a seventh voltage V7 and output it to the second control module CM2 (that is, the first auxiliary power supply module SSPM1 supplies power to the first and second control modules CM2).

[0215] The second transformer T2 mentioned above may be an industrial frequency transformer or other types of transformers, which is not limited in the embodiment of the present application.

[0216] The embodiment of the present application realizes reliable power supply of the second control module CM2 through the second transformer T2 and the first auxiliary power supply module SSPM1, thereby realizing reliable driving of the switching tube in the AC / DC power main circuit, improving the reliability of the power unit PU, and further improving the operating stability of the solid-state transformer SST.

[0217] In a possible implementation, the power unit PU can be configured as a fan for heat dissipation in the power unit. On this basis, the second auxiliary power supply circuit B can also include at least one second auxiliary power supply module SSPM2 ( Figure 13 Take the second auxiliary power circuit B including two second auxiliary power modules SSPM2 (ie, the second auxiliary power module SSPM21 and the second auxiliary power module SSPM22) as an example for description. Figure 13 shown.

[0218] from Figure 13It can be seen that the input end of each second auxiliary power supply module in the second auxiliary power supply module SSPM2 is coupled to the output end of the AC / DC power main circuit, and the output end of each second auxiliary power supply module is coupled to the fan fan.

[0219] That is, the input end of the second auxiliary power supply module SSPM21 and the input end of the second auxiliary power supply module SSPM22 are respectively coupled to the output end of the AC / DC power main circuit, and the output end of the second auxiliary power supply module SSPM21 and the output end of the second auxiliary power supply module SSPM22 are coupled to the fan fan.

[0220] exist Figure 13 Based on the above coupling relationship, each second auxiliary power module in the second auxiliary power module SSPM2 can be configured to: adjust the fifth voltage V5 to a ninth voltage V9 (i.e., the voltage required by the fan fan, which can also be considered as the output voltage of each second auxiliary power module in the second auxiliary power module SSPM2) and output it to the fan fan (which can include Figure 6 and Figure 13 The fan fan1 in the solid-state transformer and the fan fan2 of the solid-state transformer SST (since the heat dissipation of the solid-state transformer SST is achieved through the fan set on the top of the solid-state transformer SST, the fan fan2 can be called the top outlet fan of the solid-state transformer SST)).

[0221] That is to say, the second auxiliary power module SSPM21 can adjust the fifth voltage V5 to the ninth voltage V9 and output it to the fan fan. Similar to the second auxiliary power module SSPM21, the second auxiliary power module SSPM22 can also adjust the fifth voltage V5 to the ninth voltage V9 and output it to the fan fan.

[0222] At least one second auxiliary power supply module SSPM2 in the embodiment of the present application can adjust the output voltage of the AC / DC power main circuit to the voltage required by the fan fan, that is, by realizing the power supply of the fan fan, the fan fan can stably dissipate heat for the power unit PU.

[0223] In addition, each of the second auxiliary power modules SSPM2 (such as the second auxiliary power module SSPM21 and the second auxiliary power module SSPM22) also needs to be Figure 6 The third control module CM3 in PACK A is shown to be powered.

[0224] Since the output voltage of the solid-state transformer SST has multiple voltage values ​​such as 400V and 800V, the second auxiliary power supply circuit B provided in the embodiment of the present application can achieve matching of the input voltage of the second auxiliary power supply circuit B with the output voltage of the solid-state transformer SST through multiple (such as two) second auxiliary power supply modules SSPM2. The second auxiliary power supply circuit B can reliably provide auxiliary power to the power unit PU according to the different output voltages of the solid-state transformer SST (that is, the second auxiliary power supply circuit B can power the second control module CM2 according to the different output voltages of the power unit PU), thereby improving the stability of the solid-state transformer SST. At the same time, at least one second auxiliary power supply module SSPM2 in the second auxiliary power supply circuit B can adjust the output voltage of the AC / DC power main circuit to the voltage required by the fan fan, that is, by realizing the power supply of the fan fan, the fan fan can stably dissipate heat for the power unit PU.

[0225] It should be noted that, since the number of second auxiliary power supply modules in the second auxiliary power supply module can be equal to the number of AC / DC converters in the AC / DC power main circuit, the coupling relationship between the AC / DC power main circuit and the second auxiliary power supply circuit B is described in detail below, taking the AC / DC power main circuit including one AC / DC converter and the second auxiliary power supply circuit B including one second auxiliary power supply module as an example.

[0226] like Figure 14 As shown, the input of the second transformer T2 is coupled to the power grid system PS, and the output of the second transformer T2 is coupled to the input of the first auxiliary power module SSPM1. Thus, the second transformer T2 can be used to adjust the first voltage V1 from the power grid system PS to an eighth voltage V8 and output it to the first auxiliary power module SSPM1. In this embodiment of the present application, the volume of the second transformer T2 body is less than 305mm*475mm*190mm. The primary and secondary coils of the second transformer T2 are insulated by epoxy resin encapsulation.

[0227] The second transformer T2 receives a line voltage (i.e., the first voltage V1) from the power grid PS and provides an output voltage (i.e., the eighth voltage V8) exclusively to the first auxiliary power module SSPM1. The second transformer T2 has a low power consumption and size, resulting in low cost and improved reliability of the solid-state transformer SST.

[0228] refer to Figure 14The input end of the first auxiliary power supply module SSPM1 is coupled to the output end of the second transformer T2, the positive DC end DC11+ of the first AC / DC converter in the AC / DC power main circuit, and the negative DC end DC11- of the first AC / DC converter in the AC / DC power main circuit. The output end of the first auxiliary power supply module SSPM1 is coupled to the second control module CM2.

[0229] Therefore, it can be further determined that the first auxiliary power supply module SSPM1 is used to obtain the eighth voltage V8 from the second transformer T2 and obtain the DC voltage V from the positive DC terminal DC11+ of the first AC / DC converter. DC11+ and DC voltage V DC11- The first auxiliary power supply module SSPM1 obtains the second voltage V2 and the DC voltage V DC11+ and DC voltage V DC11- Based on this, the first auxiliary power module SSPM1 can adjust the voltage to the seventh voltage V7 (i.e., the output voltage of the first auxiliary power module SSPM1). The output terminal of the first auxiliary power module SSPM1 is coupled to the second control module CM2 to provide the seventh voltage V7 to the second control module CM2.

[0230] Continue to refer Figure 14 The input of the second auxiliary power module SSPM21 is coupled to the positive DC terminal DC11+ and the negative DC terminal DC11- of the first AC / DC converter, and the output of the second auxiliary power module SSPM21 is coupled to the fan fan. Similar to the second auxiliary power module SSPM21, the input of the second auxiliary power module SSPM22 is coupled to the positive DC terminal DC12+ and the negative DC terminal DC12- of the second AC / DC converter, and the output of the second auxiliary power module SSPM22 is coupled to the fan fan.

[0231] Therefore, it can be further determined that the second auxiliary power module SSPM21 is used to obtain the DC voltage V from the first AC / DC converter from the positive DC terminal DC11+ of the first AC / DC converter. DC11+ and obtains the DC voltage V from the first AC / DC converter from the negative DC terminal DC11- of the first AC / DC converter. DC11- The second auxiliary power module SSPM21 obtains the DC voltage V DC11+ and DC voltage V DC11- Based on this, the second auxiliary power module SSPM21 can convert the DC voltage V DC11+ and DC voltage V DC11-The second auxiliary power module SSPM22 is similar to the second auxiliary power module SSPM21, and is used to obtain the DC voltage V from the second AC / DC converter from the positive DC terminal DC12+ of the second AC / DC converter. DC12+ and obtains the DC voltage V from the second AC / DC converter from the negative DC terminal DC12- of the second AC / DC converter. DC12- The second auxiliary power module SSPM22 obtains the DC voltage V DC12+ and DC voltage V DC12- Based on this, the second auxiliary power module SSPM22 can convert the DC voltage V DC12+ and DC voltage V DC12- The ninth voltage V9 is adjusted to be output to the fan.

[0232] It should be noted that since the input voltage of the power unit can be medium voltage (AC power) and the output voltage of the power unit can be low voltage (DC power), and because the input ends of the first auxiliary power supply module SSPM1 and the second auxiliary power supply module SSPM2 can be coupled with the output ends of the corresponding power units, the first auxiliary power supply module SSPM1 and the second auxiliary power supply module SSPM2 can be called low-voltage auxiliary power supply modules.

[0233] In one example, Figure 13 and Figure 14 The output power of the second transformer T2 is relatively low, while the output power of the second auxiliary power module SSPM2 is relatively high. The output power of the second transformer T2 can be greater than the output power of the first auxiliary power module SSPM1, and the output power of the first auxiliary power module SSPM1 can be less than the output power of the second auxiliary power module SSPM2. For example, the output power of the first auxiliary power module SSPM1 can be 200W, the output power of the second transformer T2 can be 500W, and the output power of the second auxiliary power module SSPM2 can be 500W or 600W, etc.

[0234] In another example, Figure 14 The input voltage of the first auxiliary power module SSPM1 (which can be Figure 14 V8, V DC11+ and V DC11- ) can be 114V~840V. The input voltage of the second auxiliary power module SSPM21 (can be Figure 14 V in DC11+ and V DC11- ) can be 400V. The input voltage of the second auxiliary power module SSPM22 (can be Figure 14 V in DC12+ and V DC12-) can be 400V.

[0235] It should be noted that if Figure 14 The positive DC terminal DC11+ is connected to the positive DC terminal DC12+, and the negative DC terminal DC11- is connected to the negative DC terminal DC12-. Other connection relationships remain unchanged, and the input voltage of the second auxiliary power supply circuit B can be achieved to be 800V.

[0236] Therefore, the second auxiliary power supply circuit in the embodiment of the present application is compatible with 400V and 800V dual-output solid-state transformers SST, without the need to design a separate 400V or 800V auxiliary power supply circuit. The input voltage of the second auxiliary power supply circuit in the embodiment of the present application can be a variety of voltage levels (such as 400V and 800V), and the topology is simple and low-cost, thereby reducing the cost of the solid-state transformer SST. In addition, the input power supply of the second auxiliary power supply circuit in the embodiment of the present application does not rely on configurations other than battery or mains power, and can operate normally in battery or mains power scenarios.

[0237] Since the output voltage of the solid-state transformer is 400V and 800V, the second auxiliary power circuit in the embodiment of the present application can be Figure 14 The second auxiliary power supply module SSPM21 and the second auxiliary power supply module SSPM22 realize the matching of the input voltage of the second auxiliary power supply circuit and the output voltage of the solid-state transformer SST. The second auxiliary power supply circuit can reliably provide auxiliary power supply to the solid-state transformer SST (or the power unit PU) according to the different output voltages of the solid-state transformer SST, thereby improving the stability of the solid-state transformer SST (or the power unit PU).

[0238] It should be noted that when the input to the second auxiliary power circuit is established but the output of the power unit is not, the first auxiliary power module in the second auxiliary power circuit is operational, while all second auxiliary power modules in the second auxiliary power circuit are inoperative. When the input to the second auxiliary power circuit is established and the output of the power unit is also established, all auxiliary power modules (i.e., the first auxiliary power module and all second auxiliary power modules) are operational. In this case, the first auxiliary power module is powered by the output of the power unit.

[0239] In a transformer system composed of multiple solid-state transformers, the first auxiliary power module SSPM1 in one of the solid-state transformers can be redundant with the first auxiliary power modules in other solid-state transformers (it can also be said to be a backup for each other). When the transformer system only includes a single solid-state transformer SST (the solid-state transformer SST includes two second auxiliary power modules), the failure of any second auxiliary power module will not cause the first auxiliary power circuit to shut down, and the failed second auxiliary power module can be quickly replaced, thereby improving the stability of the power unit and thus achieving reliable operation of the solid-state transformer SST. When the transformer system includes more than two solid-state transformers SST, the replacement of any second auxiliary power module will not cause the transformer system to shut down. The first auxiliary power module and the second auxiliary power module in the first auxiliary power circuit are respectively provided with hot-swap interfaces to support hot-swap. The first auxiliary power circuit provided in the embodiment of the present application can effectively improve the stability and maintenance speed of the transformer system.

[0240] like Figure 15 As shown, the first auxiliary power supply module SSPM1 may include a second rectifier module 41 , a backflow prevention module 42 , a second voltage conversion module 43 and a third rectifier module 44 .

[0241] from Figure 15 It can be seen that the input end of the anti-backflow module 42 can be coupled with the output end of the AC / DC power main circuit (which can be an AC / DC converter in the AC / DC power main circuit), the output end of the anti-backflow module 42 can be coupled with the input end of the second rectifier module 41, the input end of the second rectifier module 41 can also be coupled with the second transformer T2, the output end of the second rectifier module 42 can be coupled with the input end of the second voltage conversion module 43, the output end of the second voltage conversion module 43 can be coupled with the input end of the third rectifier module 44, and the output end of the third rectifier module 44 can be coupled with the second control module CM2 (the output end of the third rectifier module 44 can be coupled with the second detection circuit 21 of the second control module CM2).

[0242] exist Figure 15 Based on the above coupling relationship, we can further determine:

[0243] The second rectifier module 41 can be configured to convert the fifth voltage V5 (i.e., the alternating current from the AC / DC converter in the AC / DC power main circuit) and the eighth voltage V8 (i.e., the output voltage of the second transformer T2) into an eleventh voltage V 11 (i.e., the DC voltage output by the second rectifier module 41 ) and outputs it to the second voltage conversion module 42 .

[0244] Optionally, the backflow prevention module 42 may be configured to: prevent the eleventh voltage V from the second rectifier module 41 from 11Backflow to the AC / DC power main circuit (which may be the AC / DC converter in the AC / DC power main circuit).

[0245] Optionally, the second voltage conversion module 43 may be configured to: convert the eleventh voltage V 11 Perform chopping and transform the voltage level (i.e. voltage value) (e.g., transform the voltage V 11 Step down the voltage) to obtain the twelfth voltage V 12 (ie, the AC voltage output by the second voltage conversion module 43), and the twelfth voltage V 12 Output to the third rectifier module 44.

[0246] Optionally, the third rectifier module 44 can be configured to: convert the twelfth voltage V 12 The seventh voltage V7 is obtained by rectification (ie, the DC voltage output by the third rectifier module 44 and also the DC voltage required by the second control module CM2 ), and the seventh voltage V7 is provided to the second control module CM2 .

[0247] Furthermore, the input end of the second rectifier module 41 is connected to the output end of the AC / DC converter in the AC / DC power main circuit (here, the AC / DC power main circuit includes two AC / DC converters (i.e. Figure 14 Taking the first AC / DC converter and the second AC / DC converter in FIG as an example, the output end of the AC / DC converter is reflected in Figure 16 The positive DC terminal DC11+ of the first AC / DC converter and the negative DC terminal DC12- of the second AC / DC converter are coupled, and at the same time, the input end of the second rectifier module 41 is connected to the output end ( Figure 16 The second transformer T2 is not shown in the figure. The output terminal of the second transformer T2 is Figure 16 The AC terminal AC1 (which can be AC+ or AC-) and the AC terminal AC2 (which can be AC- or AC+, corresponding to AC1) of the second rectifier module 41 are coupled. The output of the second rectifier module 41 is coupled to the input of the third rectifier module 44 via the second voltage conversion module 43. The output of the third rectifier module 44 is coupled to the second control module CM2.

[0248] In a possible implementation, the first auxiliary power module SSPM1 may have the following two topologies:

[0249] Structure 1: Figure 16 As shown, the anti-backflow module 42 may include a first switch tube (which plays a role in preventing backflow, Figure 16Taking diode D5 as an example). The second rectifier module 41 may include diode D1, diode D2, diode D3, diode D4 and capacitor C1 (capacitor C1 plays the role of rectification, filtering and energy storage). The second voltage conversion module 43 may include a fourth transformer T4 and a second switch tube ( Figure 16 Take NMOS tube as an example, that is Figure 16 NMOS2), wherein the fourth transformer T4 includes a primary winding T41 and a secondary winding T42 (it should be noted that the fourth transformer T4 also includes an iron core, and the primary winding T41 is coupled to the secondary winding T42 via the iron core). The third rectifier module 44 may include a rectifier tube (which plays a rectifying role, Figure 18 Taking diode D6 as an example) and capacitor C2 (playing the role of filtering and resistance and capacitance).

[0250] Further, refer to Figure 16 , the anode of diode D5 is coupled to the positive DC terminal DC11+, and the cathode of diode D5 is coupled to node A. After diode D1 and diode D2 are connected in series, one end is coupled to node A and the other end is coupled to node B. Node B is coupled to the negative DC terminal DC12-. In addition, the connection point of diode D1 and diode D2 ( Figure 16 Node C in the figure is coupled to the AC terminal AC1. After diode D3 and diode D4 are connected in series, one end is coupled to node A and the other end is coupled to node B. In addition, the connection point of diode D3 and diode D4 ( Figure 16 Node D in the circuit is coupled to the AC terminal AC2. Both ends of the capacitor C1 are coupled to nodes A and B, respectively. Here, it can also be said that diode D1 is connected in series with diode D2 and diode D3 is connected in series with diode D4, and then connected in parallel with capacitor C1. The same-name end of the primary winding T31 is coupled to node A, and the opposite-name end of the primary winding T41 is coupled to the drain of NMOS1. The source of NMOS1 is coupled to node B. The anode of diode D6 is coupled to the opposite-name end of the secondary winding T42, the cathode of diode D6 is coupled to node E, the same-name end of the secondary winding T32 is coupled to node F, and both ends of capacitor C2 are coupled to nodes E and F, respectively. This can be achieved by Figure 16 The first auxiliary power module SSPM1 shown in FIG. 1 obtains the seventh voltage V7, and the first auxiliary power module SSPM1 provides the seventh voltage V7 to the second control module CM2 ( Figure 16 not shown).

[0251] It should be noted that due to Figure 16 The same-name terminal of the primary winding T41 is coupled to node A, the opposite-name terminal of the primary winding T41 is coupled to node B through NMOS2, and the opposite-name terminal of the secondary winding T42 is coupled to node E through diode D6, and the same-name terminal of the secondary winding T42 is coupled to node F, so Figure 16The first auxiliary power module SSPM1 shown is a flyback topology.

[0252] In a possible implementation, the first switch tube in the backflow prevention module 42 may also be a triode or a field effect tube (which may be a junction field effect tube or an insulated gate field effect tube, taking an NMOS tube as an example).

[0253] Optionally, when the first switching tube is a transistor, the collector of the transistor is coupled to the positive DC terminal DC11+, and the emitter of the transistor is coupled to the node A.

[0254] Optionally, the first switch tube is an NMOS tube (which can be understood as Figure 16 When the diode D5 in FIG1 is replaced by an NMOS transistor, the source of the NMOS transistor is coupled to the positive DC terminal DC11+, and the drain of the NMOS transistor is coupled to the node A. It should be noted that the anode of the body diode of the NMOS transistor faces the positive DC terminal DC11+, and the cathode of the body diode of the NMOS transistor faces the node A.

[0255] In another possible implementation, the second switch tube in the second voltage conversion module 43 may also be an IGBT. Figure 16 The NMOS1 in FIG4 is replaced by an IGBT. When the second switch tube is an IGBT, the collector of the IGBT is coupled to the opposite-name terminal of the primary winding T41, and the emitter of the IGBT is coupled to the node B.

[0256] In another possible implementation, the rectifier tube in the third rectifier module 44 may be a field effect tube (which may be a junction field effect tube or an insulated gate field effect tube, taking an NMOS tube as an example). When the rectifier tube is an NMOS tube, the source of the NMOS tube is coupled to the opposite-signal terminal of the secondary winding T42, and the drain of the NMOS tube is coupled to the node E.

[0257] Structure 2: Figure 17 As shown, the anti-backflow module 42 may include a first switch tube (which plays a role in preventing backflow, Figure 17 Taking diode D5 as an example). The second rectifier module 41 may include diode D1, diode D2, diode D3, diode D4 and capacitor C1 (capacitor C1 plays the role of rectification, filtering and resistance and capacitance). The second voltage conversion module 43 may include a fourth transformer T4 and a second switch tube ( Figure 17 Take NMOS tube as an example, that is Figure 19 The fourth transformer T4 includes a primary winding T41 and a secondary winding T42 (it should be noted that the fourth transformer T4 also includes an iron core, and the primary winding T41 is coupled to the secondary winding T42 via the iron core). The third rectifier module 44 may include a diode D6, a diode D7, an inductor L1, and a capacitor C2.

[0258] Further, refer to Figure 17 , the anode of diode D5 is coupled to the positive DC terminal DC11+, and the cathode of diode D5 is coupled to node A. After diode D1 and diode D2 are connected in series, one end is coupled to node A and the other end is coupled to node B. Node B is coupled to the negative DC terminal DC12-. In addition, the connection point of diode D1 and diode D2 ( Figure 17 Node C in the figure is coupled to the AC terminal AC1. After diode D3 and diode D4 are connected in series, one end is coupled to node A and the other end is coupled to node B. In addition, the connection point of diode D3 and diode D4 ( Figure 17 Node D in the circuit is coupled to the AC terminal AC2. The two ends of the capacitor C1 are coupled to the node A and the node B respectively. Here, it can also be said that the diode D1 is connected in series with the diode D2 and the diode D3 is connected in series with the diode D4, and then connected in parallel with the capacitor C1. The same-name end of the primary winding T41 is coupled to the node A, the opposite-name end of the primary winding T41 is coupled to the drain of NMOS1, and the source of NMOS1 is coupled to the node B. The anode of the diode D6 is coupled to the same-name end of the secondary winding T32, the cathode of the diode D6 is coupled to the node E, and the opposite-name end of the secondary winding T32 is coupled to the node F. The anode of the diode D7 is coupled to the node F, and the cathode of the diode D7 is coupled to the node E. The two ends of the inductor L1 are coupled to the node E and the node G respectively. The two ends of the capacitor C2 are coupled to the node G and the node F respectively. It can be achieved through Figure 17 The first auxiliary power module SSPM1 shown in FIG. 1 obtains the seventh voltage V7, and the first auxiliary power module SSPM1 provides the seventh voltage V7 to the second control module CM2 ( Figure 17 not shown).

[0259] It should be noted that due to Figure 17 The same-name terminal of the primary winding T41 is coupled to the node A, the opposite-name terminal of the primary winding T41 is coupled to the node B through NMOS2, and the same-name terminal of the secondary winding T42 is coupled to the node E through the diode D6, and the opposite-name terminal of the secondary winding T42 is coupled to the node F, so Figure 17 The first auxiliary power supply module SSPM1 shown is a forward topology structure.

[0260] In a possible implementation, the first switch tube in the backflow prevention module 42 may also be a triode or a field effect tube (which may be a junction field effect tube or an insulated gate field effect tube, taking an NMOS tube as an example).

[0261] Optionally, when the first switching tube is a transistor, the collector of the transistor is coupled to the positive DC terminal DC11+, and the emitter of the transistor is coupled to the node A.

[0262] Optionally, the first switch tube is an NMOS tube (which can be understood as Figure 17When the diode D5 in FIG1 is replaced by an NMOS transistor, the source of the NMOS transistor is coupled to the positive DC terminal DC11+, and the drain of the NMOS transistor is coupled to the node A. It should be noted that the anode of the body diode of the NMOS transistor faces the positive DC terminal DC11+, and the cathode of the body diode of the NMOS transistor faces the node A.

[0263] In another possible implementation, the second switch tube in the second voltage conversion module 43 may also be an IGBT. Figure 17 The NMOS1 in FIG4 is replaced by an IGBT. When the second switch tube is an IGBT, the collector of the IGBT is coupled to the opposite-name terminal of the primary winding T41, and the emitter of the IGBT is coupled to the node B.

[0264] It should be noted that Figure 16 and Figure 17 The anode of diode D1 and the cathode of diode D2 are both coupled to node C, the anode of diode D3 and the cathode of diode D4 are both coupled to node D, the cathode of diode D1 and the cathode of diode D3 are both coupled to node A, and the anode of diode D2 and the anode of diode D4 are both coupled to node B.

[0265] It should also be noted that Figure 16 and Figure 17 Only two possible topological structures of the first auxiliary power module SSPM1 are given. Of course, the first auxiliary power module SSPM1 may also adopt other topological structures, which is not limited in the embodiments of the present application.

[0266] like Figure 18 As shown, the second auxiliary power module SSPM2 (which can be the second auxiliary power module SSPM21 or the second auxiliary power module SSPM22, that is, when the second auxiliary power circuit B includes the second auxiliary power module SSPM21 and the second auxiliary power module SSPM22, a total of two second auxiliary power modules, the second auxiliary power module SSPM21 and the second auxiliary power module SSPM22 can both adopt Figure 18 The structure shown) may include a power factor correction module 51 and a resonance module 52.

[0267] Furthermore, the input end of the power factor correction module 51 is coupled to the output end of the AC / DC power main circuit (which can be an AC / DC converter in the AC / DC power main circuit), the output end of the power factor correction module 51 is coupled to the input end of the resonance module 52, and the output end of the resonance module 52 is coupled to the fan fan.

[0268] It should be noted that, since both the second auxiliary power supply module SSPM21 and the second auxiliary power supply module SSPM22 can be used Figure 18As shown in the structure, the output ends of the AC / DC converter can be the positive output end DC11+ and the negative output end DC11- of the first AC / DC converter coupled to the second auxiliary power module SSPM21, or the positive output end DC12+ and the negative output end DC12- of the second AC / DC converter coupled to the second auxiliary power module SSPM22.

[0269] In a possible implementation, the first auxiliary power supply module SSPM2 may adopt the following two topologies:

[0270] Structure 1: Figure 19 As shown, the power factor correction module 51 includes a diode D1, a diode D2, a diode D3, a diode D4, a capacitor C1, an inductor L2, a diode D8, a third switch tube ( Figure 19 Take NMOS tube as an example, that is Figure 19 The resonant module 52 includes a fourth switch tube ( Figure 19 Take NMOS tube as an example, that is Figure 19 NMOS4), the fifth switch tube ( Figure 19 Take NMOS tube as an example, that is Figure 19 NMOS5), inductor L3, capacitor C4, capacitor C5, fifth transformer T5 (plays a step-down role, including primary winding T51, iron core, secondary winding T52 and secondary winding T53, the primary winding T51 is coupled with the secondary winding T52 and the secondary winding T53 through the iron core), the first rectifier tube ( Figure 19 Take NMOS tube as an example, that is Figure 19 NMOS6) and the second rectifier ( Figure 19 Take NMOS tube as an example, that is Figure 19 NMOS7).

[0271] Further, refer to Figure 19 In the power factor correction module 51, the diode D1 and the diode D2 are connected in series, one end of which is coupled to the node A and the other end is coupled to the node B. In addition, the connection point of the diode D1 and the diode D2 ( Figure 19 Node C in the circuit is coupled to the positive DC terminal DC11+ (or the positive DC terminal DC12+). After diode D3 and diode D4 are connected in series, one end is coupled to node A and the other end is coupled to node B. In addition, the connection point of diode D3 and diode D4 ( Figure 19Node D in FIG1 is coupled to the negative DC terminal DC11- (or the negative DC terminal DC12-). The two ends of capacitor C1 are coupled to node A and node B, respectively. It can also be said that diode D1 is connected in series with diode D2, and diode D3 is connected in series with diode D4, and then connected in parallel with capacitor C1. The two ends of inductor L2 are coupled to node A and node G, respectively. The source of NMOS 3 and one end of capacitor C3 are coupled to node B, the drain of NMOS 3 is coupled to node G, the other end of capacitor C3 and the cathode of diode D8 are coupled to node H, and the anode of diode D8 is coupled to node G.

[0272] Go further and continue to refer to Figure 19 In the resonant module 52, the drain of NMOS4 and one end of the capacitor C4 are coupled to the node H, the source of NMOS4, one end of the inductor L3 and the drain of NMOS5 are coupled to the node I, the other end of the capacitor C4 and one end of the capacitor C5 are coupled to the node J, and the other end of the capacitor C5 and the source of NMOS5 are coupled to the node B. The same-name end of the primary winding T51 is coupled to the other end of the inductor L3, and the opposite-name end of the primary winding T51 is coupled to the node J. The same-name end of the secondary winding T52 is coupled to the drain of NMOS6, and the opposite-name end of the secondary winding T52 is coupled to the same-name end of the secondary winding T53, and both are coupled to the node E. The opposite-name and opposite-name ends of the secondary winding T53 are coupled to the drain of NMOS7, and the source of NMOS6 and the source of NMOS7 are coupled to the node F. It can be achieved by Figure 19 The second auxiliary power module SSPM2 shown in FIG. 1 obtains the ninth voltage V9, and the second auxiliary power module SSPM2 provides the ninth voltage V9 to the fan fan ( Figure 19 not shown).

[0273] In a possible implementation, the third switch tube, the fourth switch tube, and the fifth switch tube in the power factor correction module 51 may also be IGBTs.

[0274] Optionally, when the third switch tube is an IGBT, the collector of the IGBT is coupled to the node G, and the emitter of the IGBT is coupled to the node B.

[0275] Optionally, when the fourth switch tube is an IGBT, the collector of the IGBT is coupled to the node H, and the emitter of the IGBT is coupled to the node I.

[0276] Optionally, when the fifth switch tube is an IGBT, the collector of the IGBT is coupled to the node I, and the emitter of the IGBT is coupled to the node B.

[0277] In another possible implementation, the first rectifier tube and the second rectifier tube in the resonance module 52 may also be diodes.

[0278] Optionally, when the first rectifier tube is a diode, the anode of the diode is coupled to the node F, and the cathode of the diode is coupled to the same-name end of the secondary winding T52.

[0279] Optionally, when the second rectifier tube is a diode, the anode of the diode is coupled to the node F, and the cathode of the diode is coupled to the opposite-name end of the secondary winding T53.

[0280] Structure 2: Figure 20 As shown, the power factor correction module 51 includes a diode D1, a diode D2, a diode D3, a diode D4, a capacitor C1, an inductor L2, a diode D8, a third switch tube ( Figure 20 Take NMOS tube as an example, that is Figure 20 The resonant module 52 includes a fourth switch tube ( Figure 20 Take NMOS tube as an example, that is Figure 20 NMOS4), the fifth switch tube ( Figure 20 Take NMOS tube as an example, that is Figure 20 NMOS5), inductor L3, capacitor C5, fifth transformer T5 (plays a step-down role, including primary winding T51, iron core, secondary winding T52 and secondary winding T53, primary winding T221 is coupled with secondary winding T52 and secondary winding T53 through the iron core), first rectifier tube ( Figure 20 Take NMOS tube as an example, that is Figure 20 NMOS6) and the second rectifier ( Figure 20 Take NMOS tube as an example, that is Figure 20 NMOS7).

[0281] Further, refer to Figure 20 In the power factor correction module 51, the diode D1 and the diode D2 are connected in series, one end of which is coupled to the node A and the other end is coupled to the node B. In addition, the connection point of the diode D1 and the diode D2 ( Figure 20 Node C in the circuit is coupled to the positive DC terminal DC11+ (or the positive DC terminal DC12+). After diode D3 and diode D4 are connected in series, one end is coupled to node A and the other end is coupled to node B. In addition, the connection point of diode D3 and diode D4 ( Figure 20 Node D in FIG1 is coupled to the negative DC terminal DC11- (or the negative DC terminal DC12-). The two ends of capacitor C1 are coupled to node A and node B, respectively. It can also be said that diode D1 is connected in series with diode D2, and diode D3 is connected in series with diode D4, and then connected in parallel with capacitor C1. The two ends of inductor L2 are coupled to node A and node G, respectively. The source of NMOS 3 and one end of capacitor C3 are coupled to node B, the drain of NMOS 3 is coupled to node G, the other end of capacitor C3 and the cathode of diode D8 are coupled to node H, and the anode of diode D8 is coupled to node G.

[0282] Go further and continue to refer to Figure 20 In the resonant module 52, the drain of NMOS4 is coupled to the node H, the source of NMOS4, one end of the inductor L3 and the drain of NMOS5 are coupled to the node I, and the source of NMOS5 is coupled to the node B. The same-name terminal of the primary winding T41 is coupled to the other end of the inductor L3, and the opposite-name terminal of the primary winding T51 is coupled to the node B through the capacitor C5. The same-name terminal of the secondary winding T52 is coupled to the drain of NMOS6, and the opposite-name terminal of the secondary winding T52 is coupled to the same-name terminal of the secondary winding T53, and both are coupled to the node E. The opposite-name and opposite-name terminals of the secondary winding T53 are coupled to the drain of NMOS7, and the source of NMOS6 and the source of NMOS7 are coupled to the node F. It can be achieved by Figure 20 The second auxiliary power module SSPM2 shown in FIG. 1 obtains the ninth voltage V9, and the second auxiliary power module SSPM2 provides the ninth voltage V9 to the fan fan ( Figure 20 not shown).

[0283] In a possible implementation, the third switch tube, the fourth switch tube, and the fifth switch tube in the power factor correction module 51 may also be IGBTs.

[0284] Optionally, when the third switch tube is an IGBT, the collector of the IGBT is coupled to the node G, and the emitter of the IGBT is coupled to the node B.

[0285] Optionally, when the fourth switch tube is an IGBT, the collector of the IGBT is coupled to the node H, and the emitter of the IGBT is coupled to the node I.

[0286] Optionally, when the fifth switch tube is an IGBT, the collector of the IGBT is coupled to the node I, and the emitter of the IGBT is coupled to the node B.

[0287] In another possible implementation, the first rectifier tube and the second rectifier tube in the resonance module 52 may also be diodes.

[0288] Optionally, when the first rectifier tube is a diode, the anode of the diode is coupled to the node F, and the cathode of the diode is coupled to the same-name end of the secondary winding T52.

[0289] Optionally, when the second rectifier tube is a diode, the anode of the diode is coupled to the node F, and the cathode of the diode is coupled to the opposite-name end of the secondary winding T53.

[0290] It should be noted that Figure 19 and Figure 20The anode of diode D1 and the cathode of diode D2 are both coupled to node C, the anode of diode D3 and the cathode of diode D4 are both coupled to node D, the cathode of diode D1 and the cathode of diode D3 are both coupled to node A, and the anode of diode D2 and the anode of diode D4 are both coupled to node B.

[0291] It should also be noted that Figure 19 and Figure 20 Only two possible topologies of the second auxiliary power module SSPM21 and the second auxiliary power module SSPM22 are given. Of course, the second auxiliary power module SSPM21 and the second auxiliary power module SSPM22 can also adopt other topologies, which are not limited in the embodiments of the present application.

[0292] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0293] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0294] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0295] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0296] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0297] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0298] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0299] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A solid-state transformer, characterized in that: comprising a second auxiliary power supply circuit and a plurality of power units; Each of the power units includes a first auxiliary power supply circuit, a first power circuit, a first transformer, and a second power circuit. The first power circuit includes an AC / AC power main circuit and a first control module coupled to the AC / AC power main circuit. The second power circuit includes an AC / DC power main circuit and a second control module coupled to the AC / DC power main circuit. The AC / DC power main circuit includes an input terminal and an output terminal. The input end of the first auxiliary power supply circuit is coupled to the busbar of the AC / AC power main circuit, and the output end of the first auxiliary power supply circuit is coupled to the first control module; the AC / AC power main circuit includes an input end and an output end, and the input end of the AC / AC power main circuit is coupled to the power grid power supply system; The input end of the first transformer is coupled to the output end of the AC / AC power main circuit, and the output end of the first transformer is coupled to the input end of the AC / DC power main circuit; The AC / AC power main circuit is configured to: adjust a first voltage from the grid power supply system to a second voltage and output it through an output terminal of the AC / AC power main circuit; The first control module is configured to: detect the state and / or information of the AC / AC power main circuit, and drive the AC / AC power main circuit according to the state and / or information of the AC / AC power main circuit; The first auxiliary power supply circuit is configured to: adjust the voltage of the bus of the AC / AC power main circuit to a third voltage and output it to the first control module, wherein the third voltage is used to indicate the DC voltage required by the first control module; The first transformer is configured to: adjust the second voltage into a fourth voltage and output it to the AC / DC power main circuit, wherein the fourth voltage is used to indicate the AC voltage required by the AC / DC power main circuit; The AC / DC power main circuit is configured to: rectify the fourth voltage into a fifth voltage and output the fifth voltage through the output terminal of the AC / DC power main circuit, wherein the fifth voltage is used to indicate the DC voltage output by the AC / DC power main circuit; The second control module is configured to: detect the state and / or information of the AC / DC power main circuit, and drive the AC / DC power main circuit based on the state and / or information of the AC / DC power main circuit; The input end of each power unit of the plurality of power units is connected in series to form the input end of the solid-state transformer; The output end of each power unit of the plurality of power units is connected in parallel to form the output end of the solid-state transformer; An input end of the second auxiliary power supply circuit is coupled to an output end of the AC / DC power main circuit of each power unit, and an output end of the second auxiliary power supply circuit is coupled to the second control module of each power unit; The second auxiliary power supply circuit is configured to: adjust the fifth voltage into a seventh voltage and output the seventh voltage to the second control module, wherein the seventh voltage is used to indicate a DC voltage required by the second control module; Wherein, the second auxiliary power supply circuit includes a second transformer and a first auxiliary power supply module; The input end of the second transformer is coupled to the power grid power supply system, the output end of the second transformer is coupled to the input end of the first auxiliary power module, the input end of the first auxiliary power module is also coupled to the output end of the AC / DC power main circuit, and the output end of the first auxiliary power module is coupled to the second control module; The second transformer is configured to: adjust the first voltage to an eighth voltage and output it to the first auxiliary power supply module, wherein the eighth voltage is used to indicate an AC voltage required by the first auxiliary power supply module; The first auxiliary power supply module is configured to: adjust the fifth voltage and the eighth voltage into a seventh voltage and output it to the second control module to supply power to the second control module; When the input of the second auxiliary power supply circuit is established and the output of the power unit is not established, the first auxiliary power supply module is powered by the output end of the second transformer; when the input of the second auxiliary power supply circuit is established and the output of the power unit is established, the first auxiliary power supply module is powered by the output end of the AC / DC power main circuit.

2. The solid-state transformer according to claim 1, wherein: The power unit further includes a fan, and the second auxiliary power supply circuit further includes at least one second auxiliary power supply module; An input end of each of the at least one second auxiliary power supply module is coupled to an output end of the AC / DC power main circuit, and an output end of each of the second auxiliary power supply modules is coupled to the fan; Each of the second auxiliary power modules is configured to adjust the fifth voltage to a ninth voltage and output it to the fan, where the ninth voltage is used to indicate a voltage required by the fan.

3. The solid-state transformer according to claim 2, wherein: The output power of the second transformer is greater than the output power of the first auxiliary power module; The output power of the first auxiliary power module is less than the output power of each of the second auxiliary power modules.

4. The solid-state transformer according to claim 2 or 3, characterized in that: Each of the second auxiliary power supply modules includes a power factor correction module and a resonance module; The input end of the power factor correction module is coupled to the output end of the AC / DC power main circuit, the output end of the power factor correction module is coupled to the input end of the resonance module, and the output end of the resonance module is coupled to the fan; The power factor correction module is configured to: adjust the fifth voltage to a tenth voltage, where the tenth voltage is used to indicate a voltage required by the resonance module; The resonance module is configured to convert the tenth voltage into the ninth voltage and output the ninth voltage to the fan.

5. The solid-state transformer according to any one of claims 1 to 4, characterized in that: The first auxiliary power supply module includes a second rectifier module, an anti-backflow module, a second voltage conversion module and a third rectifier module; The input end of the backflow prevention module is coupled to the output end of the AC / DC power main circuit, the output end of the backflow prevention module is coupled to the input end of the second rectifier module, the input end of the second rectifier module is also coupled to the output end of the second transformer, the output end of the second rectifier module is coupled to the input end of the second voltage conversion module, the output end of the second voltage conversion module is coupled to the input end of the third rectifier module, and the output end of the third rectifier module is coupled to the second control module; The second rectifier module is configured to: convert the fifth voltage and the eighth voltage into an eleventh voltage and output the eleventh voltage to the second voltage conversion module, wherein the eleventh voltage is used to indicate the DC voltage output by the first rectifier module; The anti-backflow module is configured to: prevent the eleventh voltage from backflowing into the AC / DC power main circuit; The second voltage conversion module is configured to: process the eleventh voltage into a twelfth voltage and output it to the third rectifier module, wherein the twelfth voltage is used to indicate the AC voltage output by the second voltage conversion module; The third rectifier module is configured to convert the twelfth voltage into the seventh voltage and output it to the second control module.

6. The solid-state transformer according to claim 5, wherein: The backflow prevention module includes a first switch tube.

7. The solid-state transformer according to claim 6, wherein: The first switch tube is a diode, a triode or a field effect tube; When the first switch tube is a diode, the anode of the diode is coupled to the output end of the AC / DC power main circuit, and the cathode of the diode is coupled to the input end of the second rectifier module; When the first switching tube is a triode, the collector of the triode is coupled to the output end of the AC / DC power main circuit, and the emitter of the triode is coupled to the input end of the second rectifier module; When the first switching tube is a field effect tube, the source of the field effect tube is coupled to the output end of the AC / DC power main circuit, and the drain of the field effect tube is coupled to the input end of the second rectifier module.

8. The solid-state transformer according to claim 1, wherein: The first control module includes a first detection circuit, a first communication circuit, a first control circuit and a first driving circuit; The input end of the first detection circuit is coupled to the AC / AC power main circuit, the output end of the first detection circuit is coupled to the input end of the first control circuit, the output end of the first control circuit is coupled to the input end of the first drive circuit, the output end of the first drive circuit is coupled to the AC / AC power main circuit, the first control circuit is further coupled to the first communication circuit, and the first communication circuit is coupled to the second control module; The first detection circuit is used to: detect the state and / or information of the AC / AC power main circuit; The first control circuit is used to: transmit the status and / or information of the AC / AC power main circuit to the first communication circuit; The first communication circuit is configured to transmit the status and / or information of the AC / AC power main circuit to the second control module, and transmit the status and / or information of the AC / DC power main circuit from the second control module to the first control circuit; The first control circuit is further configured to: send a first control command to the first drive circuit based on the state and / or information of the AC / AC power main circuit and the state and / or information of the AC / DC power main circuit; The first driving circuit is configured to drive the AC / AC power main circuit based on the first control command.

9. The solid-state transformer according to claim 8, characterized in that The second control module includes a second detection circuit, a second communication circuit, a second control circuit and a second drive circuit; An input end of the second detection circuit is coupled to the AC / DC power main circuit, an output end of the second detection circuit is coupled to an input end of the second control circuit, an output end of the second control circuit is coupled to an input end of the second drive circuit, an output end of the second drive circuit is coupled to the AC / DC power main circuit, the second control circuit is further coupled to the second communication circuit, and the second communication circuit is coupled to the first communication circuit; The second detection circuit is used to: detect the state and / or information of the AC / DC power main circuit; The second control circuit is used to: transmit the state and / or information of the AC / DC power main circuit to the first communication circuit; The second communication circuit is configured to: transmit the state and / or information of the AC / DC power main circuit to the first communication circuit, and transmit the state and / or information of the AC / DC power main circuit from the first communication circuit to the second control circuit; The second control circuit is further configured to: send a second control command to the second drive circuit based on the state and / or information of the AC / DC power main circuit and the state and / or information of the AC / AC power main circuit; The second driving circuit is configured to drive the AC / DC power main circuit based on the second control command.

10. The solid-state transformer according to any one of claims 1 to 9, characterized in that: The first auxiliary power supply circuit includes a first voltage conversion module and a first rectifier module; The input end of the first voltage conversion module is coupled to the busbar of the power unit, the output end of the first voltage conversion module is coupled to the input end of the first rectifier module, and the output end of the first rectifier module is coupled to the first control module; The first voltage conversion module is configured to: convert the voltage of the busbar of the power unit into a sixth voltage and output it to the first rectifier module, wherein the sixth voltage is used to indicate the AC voltage output by the first voltage conversion module; The first rectifier module is configured to rectify the sixth voltage into the third voltage and output it to the first control module to supply power to the first control module.

11. The solid-state transformer according to any one of claims 1 to 10, characterized in that: The voltage value of the first power circuit is higher than the voltage value of the second power circuit.

Images