Three-phase power phase sequence detection method for invertion device

Abstract

The invention discloses a three-phase power phase sequence detection method for an invertion device. The method comprises the following steps: after a switch on an alternating current side is switched on, real-time voltage of a three-phase alternating current is collected; voltage quadrature axis component and frequency deviation are calculated through a phase locking algorithm based on the quadrature axis component; after a period of fixed phase locking, in a time range of a half power frequency period, whether the voltage quadrature axis component or the frequency deviation is larger than a preset detection threshold or not is judged, wherein if the voltage quadrature axis component or the frequency deviation is larger than the preset detection threshold for consecutive N times, phase sequence errors or default phase failures are determined in the three-phase alternating current; and whether effective values of all phase voltage of the three-phase alternating current are larger than a minimum voltage input value of an alternating current system under the fixed phase power frequency or not is judged, wherein if all phase voltage amplitude is normal, the phase sequence errors of the system alternating input voltage are determined, and a fault symbol is marked. According to the method, under a condition that no hardware circuit is added, a phase sequence relation of the three-phase alternating current can be detected conveniently by combination of an original phase locked loop algorithm, and the purpose of simple, accurate and reliable phase sequence detection is achieved.

Description

technical field [0001] The invention belongs to the field of power electronics, in particular to a three-phase electric phase sequence detection method. Background technique [0002] The phase sequence relationship of three-phase AC power has a crucial influence on the normal operation of many three-phase electrical equipment, so measuring instruments must be used in most cases to ensure the correct power supply phase sequence. For example, in the control algorithms of inverters and rectifiers, the definition of the phase sequence of three-phase power supplies involves a large number of mathematical transformations and PWM control outputs. If the input terminals of the three-phase power supply are wired incorrectly, the algorithm functions cannot be realized. Another example is machine tools, hoists and other AC traction power transmission equipment. The phase sequence of the power supply voltage determines the running direction of the transmission equipment. If the power su...

AI Technical Summary

Problems solved by technology

These two methods require additional hardware circuits, which increases the complexity of the system, and is susceptible to inaccurate voltage phase judgments caused by grid voltage harmonic interference, with poor reliability; Its dynamic response is slow

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