A wind power converter based on silicon carbide devices and a power module thereof

Abstract

The utility model discloses a wind power converter and power module based on silicon carbide device, the power module includes machine side power module, chopping module, DC bus capacitor cell and net side power module, wherein, the power device used for machine side power module and net side power module is SiC MOSFET, and the power device used for chopping module is IGBT. The wind power converter and power module based on silicon carbide device of the utility model, with SiC MOSFET as power device constructs machine side power module and net side power module of power module, can reduce power device use quantity, promote the power density of wind power converter, reduce the tower drum or cabin size of wind generating set, and then reduce the system cost of wind generating set, adopt IGBT as the power device of chopping module, give full play to the characteristics of IGBT low saturation voltage drop, can improve chopping module current utilization rate.

Description

Technical Field

[0001] This utility model relates to the field of wind power generation technology, and in particular to a wind power converter and its power module based on silicon carbide devices. Background Technology

[0002] As wind turbines continue to grow in size, the current capacity of onshore wind turbines has reached 10MW to 12MW, and the capacity of offshore wind turbines has exceeded 20MW. Consequently, the required single-unit capacity of wind power converters is also constantly increasing. For example... Figure 1 As shown, existing wind power converters include grid-side power modules, machine-side power modules, and chopper modules. These components all use IGBTs as power devices. Due to the current level of IGBT devices, multiple wind power converters need to be connected in parallel to meet the needs of large-scale wind turbine generator sets. This leads to an increase in the size of the tower or nacelle used to house the wind power converter in the wind turbine generator set, as well as an increase in load.

[0003] In summary, existing wind power converters suffer from problems such as a large number of power devices, low power density, large tower or nacelle size, and low current utilization of chopper modules. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a wind power converter and its power module based on silicon carbide devices, so as to solve the problems of large number of power devices, low power density, large tower or nacelle size and low current utilization of chopper modules in existing wind power converters.

[0005] The first aspect of this utility model provides a power module, including a machine-side power module, a chopper module, a DC bus capacitor bank, and a grid-side power module, wherein the power devices used in the machine-side power module and the grid-side power module are SiC MOSFETs, and the power devices used in the chopper module are IGBTs.

[0006] Preferably, the machine-side power module includes a machine-side converter and a first heat sink for cooling the machine-side converter, the chopper module is disposed inside the machine-side power module, and the machine-side converter and the chopper module share the first heat sink; the grid-side power module includes a grid-side converter and a second heat sink for cooling the grid-side converter.

[0007] Preferably, the machine-side power module includes a machine-side converter and a first heat sink for cooling the machine-side converter; the grid-side power module includes a grid-side converter and a second heat sink for cooling the grid-side converter, the chopper module is disposed inside the grid-side power module, and the grid-side converter and the chopper module share the second heat sink.

[0008] Preferably, the machine-side power module includes a machine-side converter and a first heat sink for cooling the machine-side converter; the grid-side power module includes a grid-side converter and a second heat sink for cooling the grid-side converter; and the chopper module is provided with a third heat sink.

[0009] Preferably, both the machine-side converter and the grid-side converter adopt a three-phase two-level topology.

[0010] Preferably, the machine-side power module includes a first machine-side converter, a second machine-side converter, and a third machine-side converter, all of which employ a single-phase two-level topology; the grid-side power module includes a first grid-side converter, a second grid-side converter, and a third grid-side converter, all of which employ a single-phase two-level topology.

[0011] Preferably, the machine-side power module further includes a first heat sink for cooling the first machine-side converter, a second heat sink for cooling the second machine-side converter, and a third heat sink for cooling the third machine-side converter; the grid-side power module further includes a fourth heat sink for cooling the first grid-side converter, a fifth heat sink for cooling the second grid-side converter, and a sixth heat sink for cooling the third grid-side converter; the chopper module is provided with a seventh heat sink.

[0012] Preferably, the machine-side power module includes a machine-side converter, which adopts a three-phase three-level topology; the grid-side power module includes one grid-side converter adopting a three-phase three-level topology or three grid-side converters adopting a single-phase three-level topology; the DC bus capacitor bank includes two sets of capacitor banks, one set of capacitor banks is connected to the positive bus and the bus midpoint, and the other set of capacitor banks is connected to the bus midpoint and the negative bus; the chopper module includes a first chopper module and a second chopper module, the first chopper module is connected to the positive bus and the bus midpoint, and the second chopper module is connected to the bus midpoint and the negative bus.

[0013] The second aspect of this utility model provides a wind power converter based on silicon carbide devices, which includes at least one power unit. The power unit is connected to a generator set on the generator side and to the power grid on the grid side through a transformer. The power unit includes a generator-side filter, a power module, a chopper resistor, and a grid-side filter. The power module adopts the power module provided in the first aspect of this utility model. The generator-side filter is connected to the AC side of the generator-side power module, and the grid-side filter is connected to the AC side of the grid-side power module. The chopper resistor is connected to the chopper module and the DC bus capacitor bank, respectively.

[0014] Preferably, the chopper resistor is disposed outside the power module.

[0015] The aforementioned wind power converters and their power modules based on silicon carbide devices, using SiC MOSFETs as power devices to construct the generator-side power modules and grid-side power modules, can reduce the number of power devices used, increase the power density of the wind power converter, reduce the size of the wind turbine tower or nacelle, and thus reduce the system cost of the wind turbine. Using IGBTs as power devices in the chopper module fully utilizes the low saturation voltage drop of IGBTs, which can improve the current utilization rate of the chopper module. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the system structure of a wind turbine generator set in the existing technology. Figure 2 This is a schematic diagram of the overall structure of the wind power converter based on silicon carbide devices according to this utility model. Figure 3 The circuit of the two-level topology power module in Embodiment 1 of this utility model Figure 1 ; Figure 4 The circuit of the two-level topology power module in Embodiment 2 of this utility model Figure 2 ; Figure 5 The circuit of the two-level topology power module in Embodiment 3 of this utility model Figure 3 ; Figure 6 The circuit of the two-level topology power module in Embodiment 4 of this utility model Figure 4 ; Figure 7 This is a circuit diagram of the three-level topology power module of Embodiment 5 of this utility model. Detailed Implementation

[0017] To enable those skilled in the art to more clearly understand the purpose, technical solution and advantages of this utility model, the present utility model will be further described below in conjunction with the accompanying drawings and embodiments.

[0018] This utility model provides a wind power converter and its power module based on silicon carbide devices. For example... Figure 2As shown, the wind power converter based on silicon carbide devices includes at least one power unit. When the at least one power unit is a single power unit, the generator side of the power unit is connected to a generator set, and the grid side of the power unit is connected to the power grid through a transformer. When the at least one power unit is two or more power units (such as power unit 1, power unit 2, ..., power unit n), the generator sets are connected in parallel on the generator side of the two or more power units, and the grid sides are connected in parallel on the grid side through a transformer.

[0019] The power unit includes a machine-side filter, a power module, a chopper resistor, and a grid-side filter. The power module adopts an integrated design, including a machine-side power module, a chopper module, a DC bus capacitor bank, and a grid-side power module. The power devices used in the machine-side power module and the grid-side power module are SiC MOSFETs, and the power devices used in the chopper module are IGBTs. The machine-side filter is connected to the AC side of the machine-side power module, and the grid-side filter is connected to the AC side of the grid-side power module. The chopper resistor is connected to both the chopper module and the DC bus capacitor bank.

[0020] This invention provides a wind power converter and its power module based on silicon carbide devices. Using SiC MOSFETs as power devices to construct the generator-side and grid-side power modules of the power module reduces the number of power devices used, increases the power density of the wind power converter, and reduces the size of the wind turbine tower or nacelle, thereby lowering the system cost of the wind turbine. Employing IGBTs as the power devices in the chopper module fully utilizes the low saturation voltage drop of IGBTs, improving the current utilization rate of the chopper module. Since the chopper resistor is a high-temperature heat source, placing it outside the power module reduces the impact of the high temperature generated during operation on other components of the power module.

[0021] Example 1: Figure 3 The circuit of a two-level topology power module is shown. Figure 1 In this embodiment, the power module adopts a two-level topology and is designed as an integrated unit. Figure 3 As shown, the power module includes a machine-side power module MSC1, a DC bus capacitor bank 40, and a grid-side power module LSC1; the machine-side power module MSC1 includes a machine-side converter 10, a chopper module 20, and a first heat sink 30, and the machine-side converter 10 and the chopper module 20 share the first heat sink 30 for heat dissipation; the grid-side power module LSC1 includes a grid-side converter 50 and a second heat sink 60 for heat dissipation of the grid-side converter 50.

[0022] The machine-side converter 10 adopts a three-phase two-level topology and consists of six or a multiple of six SiC MOSFETs; the chopper module 20 includes an IGBT (one or more IGBTs connected in parallel) and a diode D1 (one or more diodes D1 connected in parallel). One end of the IGBT is connected to the negative bus, and the other end of the IGBT is connected to the anode of the diode D1. The cathode of the diode D1 is connected to the positive bus. One end of the chopper resistor Rcp is connected to the junction between the IGBT and the diode D1, and the other end of the chopper resistor Rcp is connected to the positive bus; the DC bus capacitor bank 40 includes one or more DC capacitors connected in parallel, which are connected between the positive bus and the negative bus; the grid-side converter 50 adopts a three-phase two-level topology and consists of six or a multiple of six SiC MOSFETs.

[0023] In this embodiment, the AC side voltage of the machine-side converter 10 and the grid-side converter 50 is 950V. The machine-side converter 10 and the grid-side converter 50 are constructed using 2300V / 2000A SiC MOSFET modules, wherein the SiC MOSFET module is a half-bridge structure comprising two SiC MOSFETs. In specific applications, such as in an 8.XMW application, an 8.XMW full-power wind power converter requires 18 SiC MOSFET modules for both the machine-side and grid-side converters; while a traditional 8.XMW full-power wind power converter requires 27 IGBT modules in the same package (including a half-bridge structure with two IGBTs) for both the machine-side and grid-side converters.

[0024] Comparison shows that, compared to traditional wind power converters, the wind power converter of this invention reduces the number of power devices used in the same package, increases power density, and thus reduces the size of the wind turbine tower or nacelle. Furthermore, in this embodiment, the turbine-side converter and the chopper module share a heat sink, which effectively utilizes the heat sink space and further increases the power density of the wind power converter.

[0025] Example 2: Figure 4 The circuit of a two-level topology power module is shown. Figure 2 In this embodiment, the power module adopts a two-level topology and is designed as an integrated unit. Figure 4 As shown, the power module includes a machine-side power module MSC1, a DC bus capacitor bank 40, and a grid-side power module LSC1; the machine-side power module MSC1 includes a machine-side converter 10 and a first heat sink 30 for cooling the machine-side converter 10; the grid-side power module LSC1 includes a grid-side converter 50, a chopper module 20, and a second heat sink 60, wherein the grid-side converter 50 and the chopper module 20 share the second heat sink 60 for cooling.

[0026] The machine-side converter 10 adopts a three-phase two-level topology and consists of six or a multiple of six SiC MOSFETs; the chopper module 20 includes an IGBT (one or more IGBTs connected in parallel) and a diode D1 (one or more diodes D1 connected in parallel). One end of the IGBT is connected to the negative bus, and the other end of the IGBT is connected to the anode of the diode D1. The cathode of the diode D1 is connected to the positive bus. One end of the chopper resistor Rcp is connected to the junction between the IGBT and the diode D1, and the other end of the chopper resistor Rcp is connected to the positive bus; the DC bus capacitor bank 40 includes one or more DC capacitors connected in parallel, which are connected between the positive bus and the negative bus; the grid-side converter 50 adopts a three-phase two-level topology and consists of six or a multiple of six SiC MOSFETs.

[0027] In this embodiment, the AC side voltage of the machine-side converter 10 and the grid-side converter 50 is 950V; the machine-side converter 10 and the grid-side converter 50 are constructed using a 2300V / 2000A SiC MOSFET module, wherein the SiC MOSFET module is a half-bridge structure including two SiC MOSFETs.

[0028] In this embodiment, the grid-side converter and the chopper module share a heat sink, which can effectively utilize the heat sink space and further improve the power density of the wind power converter.

[0029] Example 3: Figure 5 The circuit of a two-level topology power module is shown. Figure 3 In this embodiment, the power module adopts a two-level topology and is designed as an integrated unit. Figure 5 As shown, the power module includes a machine-side power module MSC1, a chopper module 20, a DC bus capacitor bank 40, and a grid-side power module LSC1; the machine-side power module MSC1 includes a machine-side converter 10 and a first heat sink 30 for cooling the machine-side converter 10; the grid-side power module LSC1 includes a grid-side converter 50 and a second heat sink 60 for cooling the grid-side converter 50; the chopper module 20 is provided with an independent third heat sink 203 for heat dissipation.

[0030] The machine-side converter 10 adopts a three-phase two-level topology and consists of six or a multiple of six SiC MOSFETs; the chopper module 20 includes an IGBT (one or more IGBTs connected in parallel) and a diode D1 (one or more diodes D1 connected in parallel). One end of the IGBT is connected to the negative bus, and the other end of the IGBT is connected to the anode of the diode D1. The cathode of the diode D1 is connected to the positive bus. One end of the chopper resistor Rcp is connected to the junction between the IGBT and the diode D1, and the other end of the chopper resistor Rcp is connected to the positive bus; the DC bus capacitor bank 40 includes one or more DC capacitors connected in parallel, which are connected between the positive bus and the negative bus; the grid-side converter 50 adopts a three-phase two-level topology and consists of six or a multiple of six SiC MOSFETs.

[0031] In this embodiment, the AC side voltage of the machine-side converter 10 and the grid-side converter 50 is 950V; the machine-side converter 10 and the grid-side converter 50 are constructed using a 2300V / 2000A SiC MOSFET module, wherein the SiC MOSFET module is a half-bridge structure including two SiC MOSFETs.

[0032] Example 4: Figure 6 The circuit of a two-level topology power module is shown. Figure 4 In this embodiment, the power module adopts a two-level topology and is designed as an integrated unit. Figure 6 As shown, the power module includes a machine-side power module MSC1, a chopper module 20, a DC bus capacitor bank 40, and a grid-side power module LSC1. The machine-side power module MSC1 includes a first machine-side converter 10, a second machine-side converter 11, and a third machine-side converter 12. The machine-side power module MSC1 also includes a first heat sink 102 for cooling the first machine-side converter 10, a second heat sink 112 for cooling the second machine-side converter 11, and a third heat sink 122 for cooling the third machine-side converter 12. The grid-side power module LSC1 includes a first grid-side converter 50, a second grid-side converter 51, and a third grid-side converter 52. The grid-side power module LSC1 also includes a fourth heat sink 502 for cooling the first grid-side converter 50, a fifth heat sink 512 for cooling the second grid-side converter 51, and a sixth heat sink 522 for cooling the third grid-side converter 52. The chopper module 20 is equipped with an independent seventh heat sink 203 for heat dissipation.

[0033] The first machine-side converter 10, the second machine-side converter 11, and the third machine-side converter 12 all adopt a single-phase two-level topology and are composed of two or more SiC MOSFETs. The chopper module 20 includes an IGBT (one or more IGBTs connected in parallel) and a diode D1 (one or more diodes D1 connected in parallel). One end of the IGBT is connected to the negative bus, and the other end of the IGBT is connected to the anode of the diode D1. The cathode of the diode D1 is connected to the positive bus. One end of the chopper resistor Rcp is connected to the junction between the IGBT and the diode D1, and the other end of the chopper resistor Rcp is connected to the positive bus. The DC bus capacitor bank 40 includes one or more DC capacitors connected in parallel and is connected between the positive bus and the negative bus. The first grid-side converter 50, the second grid-side converter 51, and the third grid-side converter 52 all adopt a single-phase two-level topology and are composed of two or more SiC MOSFETs.

[0034] In this embodiment, the AC side voltage of the machine-side converter 10 and the grid-side converter 50 is 950V; the machine-side converter 10 and the grid-side converter 50 are constructed using a 2300V / 2000A SiC MOSFET module, wherein the SiC MOSFET module is a half-bridge structure including two SiC MOSFETs.

[0035] In this embodiment, the chopper module 20 is set independently. In other embodiments, the chopper module 20 may also be integrated into the machine-side power module MSC1 or the grid-side power module LSC1.

[0036] Example 5: Figure 7 A circuit diagram of a three-level topology power module is shown. In this embodiment, the power module adopts a two-level topology and is designed as an integrated unit. Figure 7 As shown, the power module includes a machine-side power module MSC1, a chopper module 20, a DC bus capacitor bank 40, and a grid-side power module LSC1. The machine-side converter in the machine-side power module MSC1 adopts a three-phase three-level topology and is composed of eighteen or a multiple of eighteen SiC MOSFETs. The grid-side power module includes a grid-side converter, which also adopts a three-phase three-level topology and is composed of eighteen or a multiple of eighteen SiC MOSFETs. The DC bus capacitor bank 40 includes two sets of capacitor banks, each set including one or more parallel DC capacitors. One set of capacitor banks is connected to the positive bus and the bus midpoint, and the other set is connected to the bus midpoint and the negative bus. The chopper module includes chopper module 1 and chopper module 2. Chopper module 1 is connected to the positive bus and the bus midpoint, and chopper module 2 is connected to the bus midpoint and the negative bus.

[0037] In this embodiment, the chopper module 20 is set independently. In other embodiments, the chopper module 20 may also be integrated into the machine-side power module MSC1 or the grid-side power module LSC1.

[0038] In this embodiment, the grid-side converter of the grid-side power module LSC1 adopts a three-phase three-level topology; in other embodiments, the grid-side power module LSC1 may also include three grid-side converters, which adopt a single-phase three-level topology and are composed of six or a multiple of six SiC MOSFETs.

[0039] In summary, the wind power converter and its power module based on silicon carbide devices provided by this utility model, which uses SiCMOSFETs as power devices to construct the machine-side power module and grid-side power module of the power module, can reduce the number of power devices used, increase the power density of the wind power converter, reduce the size of the wind turbine tower or nacelle, and thus reduce the system cost of the wind turbine. Using IGBTs as power devices for the chopper module fully utilizes the low saturation voltage drop of IGBTs, which can improve the current utilization rate of the chopper module. The chopper resistor is a high-temperature heat source. Placing the chopper resistor outside the power module can reduce the impact of the high temperature generated by the chopper resistor during operation on other components of the power module.

[0040] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Those skilled in the art can make various equivalent changes and improvements based on the above embodiments. All equivalent changes or modifications made within the scope of the claims should fall within the protection scope of the present utility model.

Claims

1. A power module, characterized in that: It includes a machine-side power module, a chopper module, a DC bus capacitor bank, and a grid-side power module. The power devices used in the machine-side power module and the grid-side power module are SiCMOSFETs, and the power devices used in the chopper module are IGBTs.

2. The power module as described in claim 1, characterized in that: The machine-side power module includes a machine-side converter and a first heat sink for cooling the machine-side converter. The chopper module is disposed inside the machine-side power module, and the machine-side converter and the chopper module share the first heat sink. The grid-side power module includes a grid-side converter and a second heat sink for cooling the grid-side converter.

3. The power module as described in claim 1, characterized in that: The machine-side power module includes a machine-side converter and a first heat sink for cooling the machine-side converter; the grid-side power module includes a grid-side converter and a second heat sink for cooling the grid-side converter, and the chopper module is disposed inside the grid-side power module, and the grid-side converter and the chopper module share the second heat sink.

4. The power module as described in claim 1, characterized in that: The machine-side power module includes a machine-side converter and a first heat sink for cooling the machine-side converter; the grid-side power module includes a grid-side converter and a second heat sink for cooling the grid-side converter; the chopper module is provided with a third heat sink.

5. The power module as described in any one of claims 2-4, characterized in that: Both the machine-side converter and the grid-side converter adopt a three-phase two-level topology.

6. The power module as described in claim 1, characterized in that: The machine-side power module includes a first machine-side converter, a second machine-side converter, and a third machine-side converter, all of which adopt a single-phase two-level topology. The grid-side power module includes a first grid-side converter, a second grid-side converter, and a third grid-side converter, all of which adopt a single-phase two-level topology.

7. The power module as described in claim 6, characterized in that: The machine-side power module further includes a first heat sink for cooling the first machine-side converter, a second heat sink for cooling the second machine-side converter, and a third heat sink for cooling the third machine-side converter; the grid-side power module further includes a fourth heat sink for cooling the first grid-side converter, a fifth heat sink for cooling the second grid-side converter, and a sixth heat sink for cooling the third grid-side converter; the chopper module is provided with a seventh heat sink.

8. The power module as described in claim 1, characterized in that: The machine-side power module includes a machine-side converter, which adopts a three-phase three-level topology; the grid-side power module includes one grid-side converter adopting a three-phase three-level topology or three grid-side converters adopting a single-phase three-level topology; the DC bus capacitor bank includes two sets of capacitor banks, one set of capacitor banks is connected to the positive bus and the bus midpoint, and the other set of capacitor banks is connected to the bus midpoint and the negative bus; the chopper module includes a first chopper module and a second chopper module, the first chopper module is connected to the positive bus and the bus midpoint, and the second chopper module is connected to the bus midpoint and the negative bus.

9. A wind power converter based on silicon carbide devices, characterized in that: The system includes at least one power unit, wherein the power unit is connected to a generator set on the generator side and to the power grid on the grid side via a transformer; the power unit includes a generator-side filter, a power module, a chopper resistor, and a grid-side filter; the power module is the power module as described in any one of claims 1-8; the generator-side filter is connected to the AC side of the generator-side power module; the grid-side filter is connected to the AC side of the grid-side power module; and the chopper resistor is connected to the chopper module and the DC bus capacitor bank, respectively.

10. The wind power converter based on silicon carbide devices as described in claim 9, characterized in that: The chopper resistor is located outside the power module.

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