Flexible load regulation and control framework based on three-port flexible multi-state switch

Abstract

The utility model discloses a flexible load regulation and control framework based on a three-port flexible multi-state switch. The flexible load regulation and control framework comprises the three-port flexible multi-state switch, a first power grid module, a second power grid module and a third power grid module, the first power grid module, the second power grid module and the third power grid module are electrically connected with one another through a three-port flexible multi-state switch; the three-port flexible multi-state switch at least comprises a state A, a state B, a state C and a state D; in the A state, the first power grid module, the second power grid module and the third power grid module are mutually independent; in the B state, one power grid module in the three power grid modules is independent, and the other two power grid modules are in bidirectional power flow transfer connection; in the C state, two power grid modules in the three power grid modules are connected with the other power grid module in a tidal current transfer mode; in the D state, one power grid module in the three power grid modules is connected with the other two power grid modules in a tidal current transfer mode; and the power flow regulation and control flexibility and flexible load power supply reliability of the power distribution network are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of flexible power distribution, in particular to flexible load control based on a three-port flexible multi-state switch. Background Art

[0002] The existing distributed power sources connected to the power grid bring certain technical challenges to the distribution network. The power electronic device of the flexible multi-state switch can replace the interconnecting switch in the distribution network to solve the corresponding problem in this technical challenge; the use of the flexible multi-state switch generally utilizes the flow control capability of FMSS to restore the load power supply, using a two-port FMSS, and does not involve a coordination and cooperation architecture between three or more ports; at the same time, the existing three-port flexible multi-state switch does not provide a flexible load control architecture for the three-port flexible multi-state switch and three or more power grids. There is no specific flow transfer state in the flexible load control architecture, and no flow path in the flow transfer is provided. Summary of the invention

[0003] Purpose of the invention: In order to overcome the deficiencies in the prior art, the utility model provides a flexible load control architecture based on a three-port flexible multi-state switch to achieve flexible interconnection of multiple regions, and realize multiple working mode states and flow transfer with a three-port flexible multi-state switch; improve the flexibility of distribution network flow control and the reliability of flexible load power supply.

[0004] Technical solution: To achieve the above-mentioned purpose, the flexible load control architecture based on the three-port flexible multi-state switch of the utility model includes a three-port flexible multi-state switch, a first power grid module, a second power grid module and a third power grid module; the first power grid module, the second power grid module and the third power grid module are electrically connected to each other through the three-port flexible multi-state switch; the three-port flexible multi-state switch includes at least state A, state B, state C and state D;

[0005] In state A of the three-port flexible multi-state switch, the first power grid module, the second power grid module and the third power grid module are independent of each other; in state B, one of the first power grid module, the second power grid module and the third power grid module is independent, and the other two power grid modules are bidirectionally connected for power flow transfer; in state C, two of the first power grid module, the second power grid module and the third power grid module are connected to the other power grid module for power flow transfer; in state D, one of the first power grid module, the second power grid module and the third power grid module is connected to the other two power grid modules for power flow transfer.

[0006] Furthermore, the three-port flexible multi-state switch includes a first converter, a second converter and a third converter; the first converter, the second converter and the third converter have the same structure, and the first converter, the second converter and the third converter are connected in parallel to the same Udc capacitor.

[0007] Furthermore, the first converter, the second converter and the third converter each include a first converter submodule, a second converter submodule, a third converter submodule, a C11 capacitor and a C12 capacitor; the first converter submodule, the second converter submodule and the third converter submodule have the same circuit structure.

[0008] Furthermore, the first converter submodule, the second converter submodule and the third converter submodule each include a first IGBT module, a second IGBT module, a third IGBT module and a fourth IGBT module; the emitter of the first IGBT module and the collector of the second IGBT module are electrically connected to the negative pole of diode a; the emitter of the third IGBT module and the collector of the fourth IGBT module are electrically connected to the positive pole of diode b; the positive pole of diode a and the negative pole of diode b are electrically connected.

[0009] Furthermore, the anode of diode a of the first converter submodule, the anode of diode a of the second converter submodule and the anode of diode a of the third converter submodule are electrically connected to one end of capacitor C11 and capacitor C12; the collector of the first IGBT module of the first converter submodule, the collector of the first IGBT module of the second converter submodule and the collector of the first IGBT module of the third converter submodule are electrically connected to the other end of capacitor C11 and to one end of capacitor Udc; the emitter of the fourth IGBT module of the first converter submodule, the emitter of the fourth IGBT module of the second converter submodule and the emitter of the fourth IGBT module of the third converter submodule are electrically connected to the other end of capacitor C12 and to the other end of capacitor Udc.

[0010] Furthermore, the first power grid module is composed of a first upper power grid, a first flexible load and a first distributed power source; the three-phase power grid of the first upper power grid includes a W phase line, a V phase line and a U phase line; the W phase line is electrically connected to the emitter of the second IGBT module of the first converter submodule of the first converter; the V phase line is electrically connected to the emitter of the second IGBT module of the second converter submodule of the first converter; the U phase line is electrically connected to the emitter of the second IGBT module of the third converter submodule of the first converter.

[0011] Furthermore, the second power grid module is composed of a second upper power grid, a second flexible load and a second distributed power source; the three-phase power grid of the second upper power grid includes an A phase line, a B phase line and a C phase line; the A phase line is electrically connected to the emitter of the second IGBT module of the first converter submodule of the second converter; the B phase line is electrically connected to the emitter of the second IGBT module of the second converter submodule of the second converter; the C phase line is electrically connected to the emitter of the second IGBT module of the third converter submodule of the second converter.

[0012] Furthermore, the third power grid module is composed of a third upper-level power grid, a third flexible load and a third distributed power source; the three-phase power grid of the third upper-level power grid includes an X-phase line, a Y-phase line and a Z-phase line; the X-phase line is electrically connected to the emitter of the second IGBT module of the first converter submodule of the third converter; the Y-phase line is electrically connected to the emitter of the second IGBT module of the second converter submodule of the third converter; the Z-phase line is electrically connected to the emitter of the second IGBT module of the third converter submodule of the third converter.

[0013] Beneficial effects: The flexible load control architecture based on the three-port flexible multi-state switch of the utility model realizes flexible interconnection of multiple regions based on the flexible load control architecture of the three-port FMSS, and realizes multiple working mode states and flow transfer with the three-port flexible multi-state switch; and through multiple flow transfer working modes, reliable power supply for flexible loads in each region and high proportion of distributed power supply can be achieved; the flexibility of flow control of the distribution network and the reliability of power supply for flexible loads can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Attached Figure 1 Schematic diagram of the flexible load control architecture;

[0015] Attached Figure 2 Schematic diagram of flexible load control architecture based on three-port flexible multi-state switch;

[0016] Attached Figure 3 Three-port flexible multi-state switch circuit diagram;

[0017] Attached Figure 4 Schematic diagram of the inverter circuit;

[0018] Attached Figure 5 Schematic diagram of the A-state power flow of a three-port flexible multi-state switch;

[0019] Attached Figure 6 Schematic diagram of the B-state power flow of a three-port flexible multi-state switch;

[0020] Attached Figure 7 Schematic diagram of C-state power flow of a three-port flexible multi-state switch;

[0021] Attached Figure 8 Schematic diagram of the D-state power flow of a three-port flexible multi-state switch. DETAILED DESCRIPTION

[0022] The utility model is further described below in conjunction with the accompanying drawings.

[0023] As attached Figure 1 As shown, a flexible load control architecture based on a three-port flexible multi-state switch includes a three-port flexible multi-state switch 1, a first power grid module 2, a second power grid module 3 and a third power grid module 4; the first power grid module 2, the second power grid module 3 and the third power grid module 4 are electrically connected to each other through the three-port flexible multi-state switch 1; the three-port flexible multi-state switch 1 includes at least state A, state B, state C and state D;

[0024] In the three-port flexible multi-state switch 1, when in state A, the first grid module 2, the second grid module 3 and the third grid module 4 are independent of each other; in state B, one of the first grid module 2, the second grid module 3 and the third grid module 4 is independent, and the other two grid modules are connected for bidirectional power transfer; in state C, two of the first grid module 2, the second grid module 3 and the third grid module 4 are connected for power transfer to the other grid module; in state D, one of the first grid module 2, the second grid module 3 and the third grid module 4 is connected for power transfer to the other two grid modules.

[0025] As attached Figure 1-2 As shown, the three-port flexible multi-state switch 1 includes a first converter 5, a second converter 6 and a third converter 7; the first converter 5, the second converter 6 and the third converter 7 have the same structure, and the first converter 5, the second converter 6 and the third converter 7 are connected in parallel to the same Udc capacitor 8. The Udc capacitor 8 can play the role of voltage stabilization on the DC side. When the three-port flexible multi-state switch 1 starts to work, for example, the first grid module 2 and the second grid module 3 perform bidirectional power transfer, the electric power of the third grid module 4 is insufficient to meet the load. At this time, other grid modules are required to supply power, and the second grid module 3 is required to simultaneously transfer power to the first grid module 2 and the third grid module 4; when the IGBT module of the converter corresponding to the third grid module 4 is turned on, the second grid module 3 suddenly transfers power to the first grid module 2 and the third grid module 4 at the same time when transferring power to the first grid module 2. The voltage transferred to the first grid module 2 will be momentarily missing or fluctuating when the converter corresponding to the third grid module 4 is turned on. The Udc capacitor 8 releases the voltage at this time to stabilize the voltage transferred to the first grid module 2.

[0026] As attached Figure 3As shown, the first converter 5, the second converter 6 and the third converter 7 all include a first converter submodule 11, a second converter submodule 12, a third converter submodule 13, a C11 capacitor 14 and a C12 capacitor 15; the first converter submodule 11, the second converter submodule 12 and the third converter submodule 13 have the same circuit structure.

[0027] As attached Figure 3-4 As shown, the first converter submodule 11, the second converter submodule 12 and the third converter submodule 13 all include a first IGBT module 111, a second IGBT module 112, a third IGBT module 113 and a fourth IGBT module 114; the emitter of the first IGBT module 111 and the collector of the second IGBT module 112 are electrically connected to the cathode of diode a 115; the emitter of the third IGBT module 113 and the collector of the fourth IGBT module 114 are electrically connected to the anode of diode b 116; the anode of diode a 115 and the cathode of diode b 116 are electrically connected.

[0028] As attached Figure 3-4 As shown, the positive electrode of diode a of the first converter submodule 11, the positive electrode of diode a of the second converter submodule 12 and the positive electrode of diode a of the third converter submodule 13 are electrically connected to one end of the C11 capacitor 14 and the C12 capacitor 15; the collector of the first IGBT module of the first converter submodule 11, the collector of the first IGBT module of the second converter submodule 12 and the collector of the first IGBT module of the third converter submodule 13 are electrically connected to the other end of the C11 capacitor 14 and to one end of the Udc capacitor 8; the emitter of the fourth IGBT module of the first converter submodule 11, the emitter of the fourth IGBT module of the second converter submodule 12 and the emitter of the fourth IGBT module of the third converter submodule 13 are electrically connected to the other end of the C12 capacitor 15 and to the other end of the Udc capacitor 8.

[0029] The C11 capacitor 14 and the C12 capacitor 15 are three-level converters. The C11 capacitor 14 and the C12 capacitor 15 function as half-bridge voltage divider capacitors to ensure voltage stabilization and filtering of positive and negative voltages.

[0030] The IGBT module includes an IGBT and a diode, the collector of the IGBT is electrically connected to the negative electrode of the diode, and the emitter of the IGBT is electrically connected to the positive electrode of the diode. The gate of the IGBT module is connected to a controller that controls the IGBT module, and all IGBT modules are connected to the controller, so that the controller can control the state of the three-port flexible multi-state switch, that is, state A, state B, state C and state D.

[0031] As attached Figure 3 As shown, the first power grid module 2 is composed of a first upper power grid 21, a first flexible load 22 and a first distributed power source 23; the three-phase power grid of the first upper power grid 21 includes a W phase line 24, a V phase line 25 and a U phase line 26; the W phase line 24 is electrically connected to the emitter of the second IGBT module of the first converter submodule of the first converter 5; the V phase line 25 is electrically connected to the emitter of the second IGBT module of the second converter submodule of the first converter 5; the U phase line 26 is electrically connected to the emitter of the second IGBT module of the third converter submodule of the first converter 5.

[0032] The distributed power source may be a distributed renewable energy source, such as a solar panel or wind power generation; the distributed power source may supply power to the flexible load, and the upper-level power grid may supply power to the flexible load at the same time.

[0033] As attached Figure 3 As shown, the second power grid module 3 is composed of a second upper power grid 31, a second flexible load 32 and a second distributed power source 33; the three-phase power grid of the second upper power grid 31 includes an A phase line 34, a B phase line 35 and a C phase line 36; the A phase line 34 is electrically connected to the emitter of the second IGBT module of the first converter submodule of the second converter 6; the B phase line 35 is electrically connected to the emitter of the second IGBT module of the second converter submodule of the second converter 6; the C phase line 36 is electrically connected to the emitter of the second IGBT module of the third converter submodule of the second converter 6.

[0034] As attached Figure 3 As shown, the third power grid module 4 is composed of a third upper power grid 41, a third flexible load 42 and a third distributed power source 43; the three-phase power grid of the third upper power grid 41 includes an X-phase line 44, a Y-phase line 45 and a Z-phase line 46; the X-phase line 44 is electrically connected to the emitter of the second IGBT module of the first converter submodule of the third converter 7; the Y-phase line 45 is electrically connected to the emitter of the second IGBT module of the second converter submodule of the third converter 7; the Z-phase line 46 is electrically connected to the emitter of the second IGBT module of the third converter submodule of the third converter 7.

[0035] Example

[0036] When the controller controls the three-port flexible multi-state switch 1 to be in state A, the first grid module 2, the second grid module 3 and the third grid module 4 are independent of each other, and each grid module supplies power to its own flexible load, that is, the FMSS does not work; Figure 5 As shown, the first grid module 2, the second grid module 3 and the third grid module 4 are respectively area 1, area 2 and area 3; the three-port flexible multi-state switch 1 does not work, that is, the three ports in the three-port flexible multi-state 1 do not work, and the controller that controls the on and off of the IGBT module controls the IGBT modules in the converters corresponding to the three ports to turn off all of them, so as to realize regional self-supply, and the flexible loads in the region are powered by the distributed power sources in each region, and the surplus power is connected to the grid or supported by the upper power grid; the power flow path is as shown in the attached figure Figure 5 shown.

[0037] When the controller controls the three-port flexible multi-state switch 1 to be in state B, one of the first grid module 2, the second grid module 3 and the third grid module 4 is independent, and the other two grid modules are connected for bidirectional power flow transfer; Figure 6 As shown, when the power required by the load of the third grid module 4 is large, the electric power in the grid of the third grid module 4 is insufficient to meet the load demand, or the upper grid of the third grid module 4 fails and cannot supply power to the load, then the excess electric power of a grid module is needed to meet the load, so the excess electric power flow of a grid module needs to be transferred to the third grid module; one port of the three-port flexible multi-state switch 1 is not working, that is, the controller controls the IGBT module in the converter corresponding to the port to be turned off, and the area corresponding to the port is powered by a distributed power source or an upper grid, and the surplus power is connected to the grid or supported by the upper grid, that is, the first grid module is self-supplied; the other two of the three-port flexible multi-state switch 1 The two ports work to form a two-port back-to-back converter. The controller controls the IGBT modules in the two ports to turn on or off as needed, and the two busbars are bidirectionally transferred through the two ports; area 2 transfers power to area 3, and areas 2 and 3 can have or not have support from the upper power grid at the same time, that is, the second power grid module not only supplies power to the load of the second power grid module, but the second power grid module also transfers power to the third power grid module through the three-port flexible multi-state switch; similarly, the third power grid module not only supplies power to the load of the third power grid module, but also transfers power to the second power grid module; similarly, area 2 can be self-supplied, and area 1 and area 3 can be bidirectionally transferred; area 3 can be self-supplied, and area 1 and area 2 can be bidirectionally transferred; the flow path of the flow transfer is shown in the attached figure. Figure 6 shown.

[0038] When the controller controls the three-port flexible multi-state switch 1 to be in the C state, two of the first grid module 2, the second grid module 3 and the third grid module 4 are connected to the power flow transfer of another grid module; Figure 7 As shown, when the load of the third grid module 4 requires a larger power, the electric power in the grid of the third grid module 4 is insufficient to meet the load demand, or the upper grid of the third grid module 4 cannot supply power to the flexible load, the excess electric power of one grid module cannot meet the load, and two grid modules are required to meet the load of the third grid module 4. Therefore, the excess electric power flow of the other two grid modules needs to be transferred to the third grid module 4; the multi-area transfer single-area working mode, two of the areas transfer the power flow to another area through the three-port flexible multi-state switch 1, and the three ports are all working, and the control The controller controls the on and off of the IGBT modules of the three ports according to the situation of power transfer from two areas to another area; it transfers power to area three for area one and area two, that is, the first power grid module supplies power to the load of the first power grid module, and at the same time, the first power grid module transfers power to the third power grid module through the three-port flexible multi-state switch power, and the second power grid module supplies power to the load of the second power grid module, and at the same time, the second power grid module transfers power to the third power grid module through the three-port flexible multi-state switch power; similarly, area one and area three can transfer power to area two, or area two and area three can transfer power to area one; the power flow path of power transfer is shown in the attached figure. Figure 7 shown.

[0039] When the controller controls the three-port flexible multi-state switch 1 to be in the D state, one of the first grid module 2, the second grid module 3 and the third grid module 4 transfers power to the other two grid modules, and the three ports are all working. The controller controls the on and off of the IGBT modules of the three ports according to the power transfer from one area to the other two areas; as shown in the attached figure Figure 8 As shown, when the electric power required by the first grid module 2 and the third grid module 4 is greater, the upper grid and distributed power supply of the grid module itself are insufficient to supply the load, or the upper grid of the first grid module 2 and the third grid module 4 fails and cannot supply power to their respective loads, another grid module is required to transfer power, and the second grid module 3 is required to transfer power to the two grid modules; single-area transfer multi-area working mode, one of the areas transfers power to the other two areas through the three-port flexible multi-state switch 1; area two transfers power to area one and area three, that is, the second grid module not only supplies power to the load of the second grid module, etc., the second grid module also transfers power to the first grid module and the third grid module through the three-port flexible multi-state switch; similarly, area one can transfer power to area two and area three, or area three can transfer power to area one and area two; the power flow path of power transfer is shown in the attached figure Figure 8 shown.

[0040] The above is only a description of the preferred embodiment of the present invention. Ordinary technicians in this technical field can make several modifications and optimizations based on the above disclosure without departing from the above basic principles. These improvements and optimizations should be regarded as the understood protection scope of the present invention.

Claims

1. A flexible load control architecture based on a three-port flexible multi-state switch, characterized by: The invention comprises a three-port flexible multi-state switch (1), a first power grid module (2), a second power grid module (3) and a third power grid module (4); the first power grid module (2), the second power grid module (3) and the third power grid module (4) are electrically connected to each other via the three-port flexible multi-state switch (1); the three-port flexible multi-state switch (1) comprises at least an A state, a B state, a C state and a D state; In the three-port flexible multi-state switch (1), in state A, the first power grid module (2), the second power grid module (3) and the third power grid module (4) are independent of each other; in state B, one of the first power grid module (2), the second power grid module (3) and the third power grid module (4) is independent, and the other two power grid modules are bidirectionally connected for power flow transfer; in state C, two of the first power grid module (2), the second power grid module (3) and the third power grid module (4) are connected for power flow transfer to the other power grid module; in state D, one of the first power grid module (2), the second power grid module (3) and the third power grid module (4) is connected for power flow transfer to the other two power grid modules.

2. According to claim 1, the flexible load control architecture based on the three-port flexible multi-state switch is characterized in that: The three-port flexible multi-state switch (1) comprises a first converter (5), a second converter (6) and a third converter (7); the first converter (5), the second converter (6) and the third converter (7) have the same structure, and the first converter (5), the second converter (6) and the third converter (7) are connected in parallel to the same Udc capacitor (8).

3. The flexible load control architecture based on the three-port flexible multi-state switch according to claim 2 is characterized in that: The first converter (5), the second converter (6) and the third converter (7) all comprise a first converter submodule (11), a second converter submodule (12), a third converter submodule (13), a C11 capacitor (14) and a C12 capacitor (15); the first converter submodule (11), the second converter submodule (12) and the third converter submodule (13) have the same circuit structure.

4. The flexible load control architecture based on the three-port flexible multi-state switch according to claim 3 is characterized in that: The first converter submodule (11), the second converter submodule (12) and the third converter submodule (13) all comprise a first IGBT module (111), a second IGBT module (112), a third IGBT module (113) and a fourth IGBT module (114); the emitter of the first IGBT module (111) and the collector of the second IGBT module (112) are electrically connected to the negative electrode of diode a (115); the emitter of the third IGBT module (113) and the collector of the fourth IGBT module (114) are electrically connected to the positive electrode of diode b (116); the positive electrode of diode a (115) and the negative electrode of diode b (116) are electrically connected.

5. The flexible load control architecture based on a three-port flexible multi-state switch according to claim 4 is characterized in that: The anode of the diode a of the first converter submodule (11), the anode of the diode a of the second converter submodule (12) and the anode of the diode a of the third converter submodule (13) are electrically connected to one end of the C11 capacitor (14) and the C12 capacitor (15); the collector of the first IGBT module of the first converter submodule (11), the collector of the first IGBT module of the second converter submodule (12) and the collector of the first IGBT module of the third converter submodule (13) are electrically connected to the other end of the C11 capacitor (14) and to one end of the Udc capacitor (8); the emitter of the fourth IGBT module of the first converter submodule (11), the emitter of the fourth IGBT module of the second converter submodule (12) and the emitter of the fourth IGBT module of the third converter submodule (13) are electrically connected to the other end of the C12 capacitor (15) and to the other end of the Udc capacitor (8).

6. The flexible load control architecture based on a three-port flexible multi-state switch according to claim 1 is characterized in that: The first power grid module (2) is composed of a first upper power grid (21), a first flexible load (22) and a first distributed power source (23); the three-phase power grid of the first upper power grid (21) includes a W phase line (24), a V phase line (25) and a U phase line (26); the W phase line (24) is electrically connected to the emitter of the second IGBT module of the first converter submodule of the first converter (5); the V phase line (25) is electrically connected to the emitter of the second IGBT module of the second converter submodule of the first converter (5); and the U phase line (26) is electrically connected to the emitter of the second IGBT module of the third converter submodule of the first converter (5).

7. The flexible load control architecture based on a three-port flexible multi-state switch according to claim 1 is characterized in that: The second power grid module (3) is composed of a second upper power grid (31), a second flexible load (32) and a second distributed power source (33); the three-phase power grid of the second upper power grid (31) includes an A phase line (34), a B phase line (35) and a C phase line (36); the A phase line (34) is electrically connected to the emitter of the second IGBT module of the first converter submodule of the second converter (6); the B phase line (35) is electrically connected to the emitter of the second IGBT module of the second converter submodule of the second converter (6); and the C phase line (36) is electrically connected to the emitter of the second IGBT module of the third converter submodule of the second converter (6).

8. The flexible load control architecture based on a three-port flexible multi-state switch according to claim 1 is characterized in that: The third power grid module (4) is composed of a third upper power grid (41), a third flexible load (42) and a third distributed power source (43); the three-phase power grid of the third upper power grid (41) includes an X-phase line (44), a Y-phase line (45) and a Z-phase line (46); the X-phase line (44) is electrically connected to the emitter of the second IGBT module of the first converter submodule of the third converter (7); the Y-phase line (45) is electrically connected to the emitter of the second IGBT module of the second converter submodule of the third converter (7); and the Z-phase line (46) is electrically connected to the emitter of the second IGBT module of the third converter submodule of the third converter (7).

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