CN-121710511-B - Power supply switching control method and power supply switching device

CN121710511BCN 121710511 BCN121710511 BCN 121710511BCN-121710511-B

Abstract

The invention discloses a power supply switching control method and a power supply switching device. The method comprises the steps of monitoring a fault state of a power supply branch in a power supply switching device, determining a fault type of the power supply branch when the fault state is that the power supply branch breaks down, determining an execution strategy corresponding to the fault type, wherein the execution strategy comprises an execution sequence of turning off a power supply circuit and turning on a voltage compensation circuit, and sending a control instruction to the power supply switching device, wherein the control instruction carries the execution strategy to turn off the power supply circuit and the voltage compensation circuit according to the execution sequence, then turning on a standby circuit, and switching the power supply of a power inlet wire corresponding to the power supply circuit to the power supply of the power inlet wire corresponding to the standby circuit. The invention solves the technical problems that when the power supply is switched in the related technology, a unified switching strategy is generally adopted, different switching situations cannot be targeted, and untimely protection or switching fluctuation is easy to cause.

Inventors

CAI JING
YANG YAQI
ZHANG YING
WANG FANG
ZHAO BIN
WU PEIFEI
CHEN LONGLONG

Assignees

国网北京市电力公司
北京怀柔实验室
北京鼎诚鸿安科技发展有限公司

Dates

Publication Date: 20260508
Application Date: 20260214

Claims (9)

1. A power supply switching control method, characterized by comprising: The method comprises the steps of monitoring a fault state of a power supply branch circuit in a power supply switching device, wherein the power supply switching device comprises a plurality of switch circuits (101) and a voltage compensation circuit (201), the switch circuits (101) comprise a power supply circuit and a standby circuit, the voltage compensation circuit (201) comprises an energy storage unit, a rectifying and inverting unit and an injection type transformer, input ends of the switch circuits (101) are respectively and electrically connected with a corresponding power supply inlet wire (D1), output ends of the switch circuits (101) are connected in parallel and then electrically connected with a load end (D2), input ends of the rectifying and inverting unit are electrically connected with the energy storage unit, output ends of the rectifying and inverting unit are electrically connected with the input end of the injection type transformer, and output ends of the injection type transformer are connected with the output ends of the switch circuits (101) in parallel and then electrically connected with the load end (D2); determining the fault type of the power supply branch circuit when the fault state is that the power supply branch circuit fails; Determining an execution strategy corresponding to the fault type, wherein the execution strategy comprises an execution sequence of switching off the power supply circuit and switching on the voltage compensation circuit (201); sending a control instruction to the power supply switching device, wherein the control instruction carries the execution strategy so as to switch off the power supply circuit and switch on the voltage compensation circuit (201) according to the execution sequence, and then switch on the standby circuit to switch the power supply of a power supply inlet wire (D1) corresponding to the power supply circuit to the power supply inlet wire (D1) corresponding to the standby circuit; The method comprises the steps of determining an execution strategy corresponding to the fault type, wherein the execution strategy is determined to be a first strategy when the fault type is a voltage sag fault and/or a harmonic exceeding fault, the first strategy comprises an execution sequence of switching on the voltage compensation circuit (201) in advance of an execution sequence of switching off the power supply circuit so as to compensate sag voltage, and the second strategy is determined to be a second strategy when the fault type is a short-circuit fault, and the second strategy comprises an execution sequence of switching off the power supply circuit in advance of the execution sequence of switching on the voltage compensation circuit (201) so as to limit short-circuit current.
2. The method of claim 1, wherein determining an execution policy corresponding to the fault type comprises: determining a load demand voltage value and an output voltage value corresponding to the power supply circuit under the condition that an execution strategy is a first strategy, wherein the first strategy comprises the output voltage value corresponding to the voltage compensation circuit (201); Determining an instantaneous compensation voltage value according to the load demand voltage value and the output voltage value; Determining an output voltage value corresponding to the voltage compensation circuit (201) as the instantaneous compensation voltage value, so that the voltage compensation circuit (201) outputs the instantaneous compensation voltage value.
3. The method of claim 1, further comprising, prior to monitoring the power switching device for a fault condition of the power supply branch: Determining a load rated power corresponding to the load end, wherein the direct-current side voltage value of the energy storage unit, the maximum voltage sag value, the maximum sag duration time and the system rated voltage value of a power system, the direct-current side voltage is determined according to the unit parameters of the rectifying and inverting unit, and the power system comprises power switching equipment, a power end and the load end; Determining a first ratio of the maximum voltage dip value to a system rated voltage value and determining a first product of the load rated power and the maximum dip duration; determining a second product of the first product and the first ratio to obtain a single electrical energy required by the voltage compensation circuit (201) in a single voltage dip; determining the ratio of the preset multiple of the single electric energy to the square of the direct current side voltage value to obtain a direct current side capacitance value of the energy storage unit; and configuring the energy storage unit according to the direct current side capacitance value.
4. A method according to any one of claims 1 to 3, wherein the fault type comprises at least one of: determining that the fault type is a sag voltage fault under the condition that the phase voltage effective value of the power supply circuit is lower than a preset voltage threshold value; Under the condition that the voltage total harmonic distortion rate of the power supply circuit is higher than a preset proportion, determining that the fault type is a harmonic exceeding fault; And determining that the fault type is a short circuit fault in the case that the current amplitude of the power supply circuit is higher than a preset current threshold value.
5. The power supply switching device is characterized by comprising a plurality of switching circuits (101), a voltage compensation circuit (201) and a controller, wherein the voltage compensation circuit (201) comprises an energy storage unit, a rectifying inversion unit and an injection type transformer, The input ends of the switch circuits (101) are respectively and electrically connected with corresponding power supply inlet wires (D1), and the output ends of the switch circuits (101) are connected in parallel and then are electrically connected with a load end (D2); the input end of the rectification inversion unit is electrically connected with the energy storage unit, and the output end of the rectification inversion unit is electrically connected with the input end of the injection transformer; the output end of the injection transformer is electrically connected with the load end (D2) after being connected with the output ends of the switch circuits (101) in parallel; The controller is electrically connected with the switch circuits (101) and the voltage compensation circuit (201) respectively, and is used for integrating control programs corresponding to the power switching control method according to claim 1 so as to execute corresponding control when a power switching request is received.
6. The device according to claim 5, wherein the power switching device further comprises a parameter acquisition sensor, the acquisition end of the parameter acquisition sensor is electrically connected with the power supply circuit and the load end (D2) and is used for acquiring an output voltage value corresponding to the load demand voltage value and the power supply circuit, and the signal output end of the parameter acquisition sensor is electrically connected with the controller so as to transmit the acquired load demand voltage value and the output voltage value to the controller, so that the controller determines the instantaneous compensation voltage value.
7. An electronic device, comprising: A processor; a memory for storing the processor-executable instructions; Wherein the processor is configured to execute the instructions to implement the method of any one of claims 1 to 4.
8. A computer readable storage medium, characterized in that instructions in the computer readable storage medium, when executed by a processor of an electronic device, enable the electronic device to perform the method of any one of claims 1 to 4.
9. A computer program product comprising computer instructions which, when executed by a processor, implement the steps of the method of any one of claims 1 to 4.

Description

Power supply switching control method and power supply switching device Technical Field The invention relates to the field of power systems, in particular to a power supply switching control method and a power supply switching device. Background In an electric power system, a power supply switching device needs to cope with various faults such as short circuit, voltage sag, and the like of a power supply branch. However, in the related art, a unified switching strategy is generally adopted when the power supply is switched, which is easy to cause the problems of untimely protection or voltage fluctuation in the switching process, and the stable operation of the load is affected. In view of the above problems, no effective solution has been proposed at present. Disclosure of Invention The embodiment of the invention provides a power supply switching control method and a power supply switching device, which at least solve the technical problems that when power supplies are switched in the related technology, a unified switching strategy is generally adopted, different switching situations cannot be correspondingly dealt with, and protection is not timely or switching fluctuation is easy to cause. According to one aspect of the embodiment of the invention, a power supply switching control method is provided, which comprises monitoring a fault state of a power supply branch in a power supply switching device, wherein the power supply switching device comprises a plurality of switch circuits and a voltage compensation circuit, the switch circuits comprise a power supply circuit and a standby circuit, the voltage compensation circuit comprises an energy storage unit, a rectification inversion unit and an injection type transformer, input ends of the switch circuits are respectively and electrically connected with corresponding power supply inlet wires, output ends of the switch circuits are connected in parallel and are electrically connected with a load end, input ends of the rectification inversion unit are electrically connected with the energy storage unit, output ends of the rectification inversion unit are electrically connected with input ends of the injection type transformer, output ends of the injection type transformer are connected with output ends of the switch circuit in parallel and are electrically connected with the load end, under the condition that the fault state is that the power supply branch breaks down, execution strategies corresponding to the fault types are determined, the execution strategies corresponding to the fault types are respectively, the execution strategies are included, the power supply strategies are connected with the load end wires in parallel, the output ends of the switch-on strategy are connected with the input ends of the switch-off control circuit, and the power supply control circuit is carried by the standby circuit according to a power supply switching order, and the power supply control instructions are carried by the input wire switching strategy is carried by the standby circuit. Optionally, determining an execution strategy corresponding to the fault type comprises determining that the execution strategy is a first strategy when the fault type is a voltage sag fault and/or a harmonic exceeding fault, wherein the first strategy comprises an execution sequence of switching on the voltage compensation circuit before an execution sequence of switching off the power supply circuit to compensate sag voltage, and determining that the execution strategy is a second strategy when the fault type is a short circuit fault, wherein the second strategy comprises an execution sequence of switching off the power supply circuit before an execution sequence of switching on the voltage compensation circuit to limit short circuit current. Optionally, determining an execution strategy corresponding to the fault type includes determining an output voltage value corresponding to a load demand voltage value and the power supply circuit when the execution strategy is a first strategy, determining an instantaneous compensation voltage value according to the load demand voltage value and the output voltage value, and determining the output voltage value corresponding to the voltage compensation circuit as the instantaneous compensation voltage value so that the voltage compensation circuit outputs the instantaneous compensation voltage value. Optionally, before monitoring the fault state of the power supply branch in the power supply switching device, determining a direct current side voltage value of the energy storage unit, a maximum voltage sag value, a maximum sag duration time and a system rated voltage value of a power system, wherein the direct current side voltage is determined according to unit parameters of the rectifying and inverting unit, the power system is a system comprising the power supply switching device, a power supply end and the load end, determining a first ratio