A three-phase phase sequence adaptive control method and system based on positive and negative identification

Abstract

The invention provides a positive and negative recognition based three-phase phase sequence self-adaptive control method and system. The positive and negative recognition based three-phase phase sequence self-adaptive control method includes steps of S1, judging whether valid values of three phase AC voltage of an A phase, a B phase and a C phase of a power grid are all in a normal range or not, proceeding to step S2 if the values are all in the normal range, or sending alarm signals if the values are not all in the normal range; S2, synthesizing a vector equivalently according to the three-phase AC voltage and obtaining the rotation angle of the synthesized vector; S3, judging whether the power grid voltage phase sequence is a negative sequence or not through the rotation angle of the synthesized vector, and exchanging a positive and negative sequence component calculation result obtained via the power grid voltage positive sequence if the power grid voltage phase is judged to be the negative sequence; S4, during reversal processing of the power grid voltage phase sequence, multiplexing a transformation formula of the power grid voltage positive sequence from a static coordinate system or a rotary coordinate system. According to the invention, a capturing circuit is not needed to add to a three-phase power electric device and power line distribution change and cost increase are saved, and phase sequence lock and control of the three-phase power electric device are realized.

Description

technical field [0001] The present invention relates to a three-phase phase sequence control method, in particular to a three-phase phase sequence adaptive control method based on positive and negative identification, and to a three-phase phase sequence adaptive control method based on positive and negative identification. Phase sequence adaptive control system. Background technique [0002] With the development of the power electronics industry, a large number of power electronic equipment such as SVG (static var compensator), APF (active filter), charging piles, and energy storage devices have been put into use in the three-phase power grid. Phase sequence automatic adaptive identification control has always been a difficult point in the industry. At present, the wiring of many three-phase systems has no markings, or the markings are unclear, and it is difficult to clearly analyze the phase sequence of the ABC three-phase. For some non-hot-swappable and hot-swappable dev...

AI Technical Summary

Problems solved by technology

Since the controller is generally based on the positive sequence control of the power grid, after the equipment reports a phase sequence fault, it needs to be rewired, which wastes a lot of manpower and material resources

[0003] That is to say, there are the following defects in the prior art: 1. The three-phase power electronic equipment uses its own detection device to detect phase sequence reversal, and alarm after detection of reverse connection. This requires manual rewiring, which is very cumbersome and wastes Human and material resources

2. The reversing device is added to the three-phase power electronic equipment, and any two phases can be exchanged to replace the manual wiring change. Although this can achieve the effect of replacing the manual rewiring, the added automatic reversing device increases virtually. In addition, connecting similar switching devices in series will also reduce system reliability

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