Parallel inverter wireless carrier synchronization method and device, medium and computer equipment

Abstract

The invention relates to a parallel inverter wireless carrier synchronization method and device, a storage medium and computer equipment. The power grid three-phase voltage is sampled according to thesampling period of parallel inverters, and the power grid three-phase voltage instantaneous value under a three-phase static symmetric coordinate system is converted into the voltage signal of a two-phase vertical static coordinate system; the voltage signal of the two-phase vertical static coordinate system is converted into the voltage signal under two-phase synchronous rotation coordinates according to a preset inverter sine and cosine table; when the voltage signal under the two-phase synchronous rotation coordinates is not zero, proportional integral operation is performed according to the voltage signal under the two-phase synchronous rotation coordinates so as to obtain the sampling error; and the sampling period is updated according to the sampling error and the power grid three-phase voltage is sampled again. The error is gradually decreased through feedback adjustment and synchronous modulation and phase locking of each parallel inverter is completed without additional arrangement of the carrier synchronous signal line so that wireless carrier synchronization of each parallel inverter can be realized and the reliability of wireless parallel operation can be enhanced.

Description

technical field [0001] The invention relates to the technical field of power grids, in particular to a method, device, storage medium and computer equipment for carrier synchronization of parallel inverters. Background technique [0002] With the increase of electrical equipment and the improvement of power level requirements, the parallel connection of inverters is more and more widely used. The inverter parallel system makes the system power be reasonably allocated among the inverters according to their rated capacity, so that the circulating current between the inverters is suppressed. If there is a circulating current in the inverter parallel system, it will affect the reliable operation of the system. The circulating current is divided into power frequency circulating current, harmonic circulating current, DC circulating current, etc. These circulating currents are load-shared through the average current control method or virtual impedance control method, but there is ...

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Problems solved by technology

If there is a circulating current in the inverter parallel system, it will affect the reliable operation of the system

The circulating current is divided into power frequency circulating current, harmonic circulating current, DC circulating current, etc. These circulating currents are load-shared through the average current control method or virtual impedance control method, but there is another kind of circulating current in the parallel system called switch circulating current, that is, inverter The difference of the modulated carrier of the inverter module will also cause a certain degree of switching frequency ripple in the output current. This circulating current cannot be suppressed by the average current and virtual impedance, so the consistency of the modulated carrier of the inverter module must be solved

[0003] The carrier synchronization method of the traditional inverter parallel system is to add a carrier synchronization communication line between the parallel units to achieve carrier synchronization, but it increases the hardware cost and the risk of hardware failure, and it is based on the carrier synchronization communication line to achieve carrier synchronization. The effect of synchronization belongs to wired parallel machine, and it cannot realize wireless parallel machine carrier synchronization

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