Search

CN-121984099-A - Power grid phase sequence determination method, device, controller and system of power converter

CN121984099ACN 121984099 ACN121984099 ACN 121984099ACN-121984099-A

Abstract

The application relates to a method, a device, a controller and a system for determining a power grid phase sequence of a power converter. The method comprises the steps of sending a first instruction to a target single-phase power converter when all the single-phase power converters are in a grid-connected state, obtaining alternating current bus messages corresponding to all the power grid phase sequences on an alternating current bus through an electric quantity sensor arranged on the alternating current bus corresponding to all the power grid phase sequences, and determining the power grid phase sequences corresponding to the target single-phase power converter based on the alternating current bus messages corresponding to all the power grid phase sequences. By adopting the method, the grid-connected starting efficiency of the single-phase power converter can be improved.

Inventors

  • WEI FENG

Assignees

  • 上海摩瓦新能源科技有限公司

Dates

Publication Date
20260505
Application Date
20260330

Claims (13)

  1. 1. A method for determining a grid phase sequence of a power converter, the method for determining a grid phase sequence corresponding to each single-phase power converter connected to a multiphase grid system, the method comprising: Transmitting a first instruction to a target single-phase power converter when all the single-phase power converters are in a grid-connected state, wherein the first instruction is used for instructing the corresponding single-phase power converter to output according to first power, and the target single-phase power converter is any one of the single-phase power converters which do not determine the phase sequence of a power grid; Acquiring alternating current bus messages corresponding to the phase sequences of the power grids respectively through electric quantity sensors arranged on the alternating current buses corresponding to the phase sequences of the power grids; And determining the power grid phase sequence corresponding to the target single-phase power converter based on the alternating current bus messages respectively corresponding to the power grid phase sequences.
  2. 2. The method of claim 1, wherein the first instruction is configured to instruct the corresponding single-phase power converter to decrease or increase the current output power by a preset power step, to obtain the first power, and output according to the first power; The determining the target phase sequence corresponding to the target single-phase power converter according to the alternating current bus messages respectively corresponding to the power grid phase sequences comprises the following steps: determining the phase sequence of the power grid, in which the alternating current bus message changes, from the phase sequences of the power grids; and determining the power grid phase sequence corresponding to the target single-phase power converter based on the power grid phase sequence of the alternating-current bus message.
  3. 3. The method according to claim 1, wherein the method further comprises: And sending a second instruction to the other single-phase power converters, wherein the second instruction is used for instructing the corresponding single-phase power converters to output according to second power, the second power is not equal to the first power, and the other single-phase power converters are single-phase power converters except for the target single-phase power converter in the single-phase power converters with the undetermined power grid phase sequence.
  4. 4. The method of claim 3, wherein the first power is greater than a power sum, the power sum being an accumulated value of a second power corresponding to the remaining single-phase power converters.
  5. 5. A method according to claim 3, wherein the number of single-phase power converters corresponding to each grid phase sequence is the same, and the first power is greater than the second power.
  6. 6. The method of claim 4 or 5, wherein the ac bus message includes ac bus power, wherein the determining the grid phase sequence corresponding to the target single-phase power converter based on the ac bus message corresponding to each of the grid phase sequences includes: Determining a power grid phase sequence with the maximum alternating current bus power from the power grid phase sequences; And determining the power grid phase sequence corresponding to the target single-phase power converter based on the power grid phase sequence with the maximum alternating-current bus power.
  7. 7. The method of claim 3, wherein the number of single-phase power converters corresponding to each grid phase sequence is the same, and wherein the first power is less than the second power.
  8. 8. The method of claim 7, wherein the ac bus message comprises ac bus power; the determining the grid phase sequence corresponding to the target single-phase power converter based on the alternating current bus messages respectively corresponding to the grid phase sequences comprises the following steps: determining a power grid phase sequence with minimum alternating current bus power from the power grid phase sequences; and determining the power grid phase sequence corresponding to the target single-phase power converter based on the power grid phase sequence with the minimum alternating-current bus power.
  9. 9. The method according to any one of claims 3-5, 7 and 8, further comprising: the second instruction is sent to a single-phase power converter for which the grid phase sequence has been determined.
  10. 10. The method of claim 1, wherein prior to said sending the first instruction to the target single-phase power converter, the method further comprises: And sending a third instruction to all the single-phase power converters, wherein the third instruction is used for instructing the corresponding single-phase power converters to output according to the third power.
  11. 11. A power grid phase sequence determining apparatus for power converters, the apparatus for determining a power grid phase sequence corresponding to each single-phase power converter connected to a multi-phase power grid system, the apparatus comprising: The control module is used for sending a first instruction to a target single-phase power converter when all the single-phase power converters are in a grid-connected state, wherein the first instruction is used for indicating the corresponding single-phase power converter to output according to first power, and the target single-phase power converter is any one of the single-phase power converters which do not determine the phase sequence of a power grid; the acquisition module is used for acquiring alternating current bus messages corresponding to the phase sequences of the power grids respectively through the electric quantity sensors arranged on the alternating current buses corresponding to the phase sequences of the power grids; And the determining module is used for determining the grid phase sequence corresponding to the target single-phase power converter based on the alternating current bus messages respectively corresponding to the grid phase sequences.
  12. 12. A controller comprising a memory storing a computer program and a processor implementing the steps of the method of any one of claims 1 to 10 when the computer program is executed.
  13. 13. The power system is characterized by comprising a plurality of single-phase power converters and a controller, wherein the controller is in communication connection with each single-phase power converter; the controller comprising a memory storing a computer program and a processor implementing the steps of the method of any of claims 1 to 10 when the computer program is executed.

Description

Power grid phase sequence determination method, device, controller and system of power converter Technical Field The application relates to the technical field of new energy, in particular to a method, a device, a controller and a system for determining a power grid phase sequence of a power converter. Background In a photovoltaic three-phase system, a plurality of single-phase power converters (e.g., micro-inverters) are respectively connected to a first phase circuit, a second phase circuit and a third phase circuit of a three-phase power grid system. In order to improve the power generation efficiency or balance the three-phase output, the power grid phase sequence of each single-phase power converter in the three-phase power grid system needs to be accurately determined, namely, which phase circuit each single-phase power converter is connected to is determined, so that the single-phase power converter corresponding to each phase circuit can be controlled independently. The method for determining the phase sequence of the power grid in the related art is to record the phase sequence of the single-phase power converter in a manual mode when the single-phase power converter is connected to a three-phase power grid, and configure the topological relation of the single-phase power converter in a gateway controller according to recorded data. However, the adoption of the method for determining the phase sequence of the power grid can result in poor starting efficiency of grid connection of each single-phase power converter. Disclosure of Invention In view of the foregoing, it is desirable to provide a method, apparatus, controller and system for determining a power grid phase sequence of a power converter that improves switching efficiency. In a first aspect, the present application provides a method for determining a phase sequence of a power converter, where the method is used for determining a phase sequence of a power network corresponding to each single-phase power converter connected to a multiphase power network system, and the method includes: Transmitting a first instruction to a target single-phase power converter when all the single-phase power converters are in a grid-connected state, wherein the first instruction is used for instructing the corresponding single-phase power converter to output according to first power, and the target single-phase power converter is any one of the single-phase power converters which do not determine the phase sequence of a power grid; Acquiring alternating current bus messages corresponding to the phase sequences of the power grids respectively through electric quantity sensors arranged on the alternating current buses corresponding to the phase sequences of the power grids; and determining the power grid phase sequence corresponding to the target single-phase power converter based on the alternating current bus messages respectively corresponding to the power grid phase sequences. In one embodiment, the first instruction is configured to instruct the corresponding single-phase power converter to decrease or increase the current output power by a preset power step, obtain a first power, and output according to the first power; determining a target phase sequence corresponding to the target single-phase power converter according to the alternating-current bus messages respectively corresponding to the power grid phase sequences, wherein the method comprises the following steps: Determining the phase sequence of the power grid, in which the alternating current bus message changes, from the phase sequences of the power grids; and determining the power grid phase sequence corresponding to the target single-phase power converter based on the power grid phase sequence of the alternating-current bus message. In one embodiment, the first power is greater than a sum of powers, the sum of powers being an accumulated value of the second powers corresponding to the remaining single-phase power converters. In one embodiment, the number of single-phase power converters corresponding to each grid phase sequence is the same, and the first power is greater than the second power. In one embodiment, the AC bus message comprises AC bus power, and the determining the grid phase sequence corresponding to the target single-phase power converter based on the AC bus message corresponding to each grid phase sequence comprises the following steps: determining a power grid phase sequence with the maximum alternating current bus power from the power grid phase sequences; and determining the power grid phase sequence corresponding to the target single-phase power converter based on the power grid phase sequence with the maximum alternating-current bus power. In one embodiment, the number of single-phase power converters corresponding to each grid phase sequence is the same, and the first power is smaller than the second power. In one embodiment, the ac bus message includes ac bus power; Determ