Three-phase electricity phase sequence judging method

Abstract

The present invention relates to a three-phase electricity phase sequence judging method for judging the three-phase electricity phase sequence on the basis of the voltage vector u-tilde(k) in the current period and the voltage vector u-tilde(k-1) in the previous period. The phase sequence judging method has the low computational complexity and is simple so as to greatly ease the burden of a processor and improve the phase sequence detection efficiency. The three-phase electricity phase sequence judging method can be widely used under severe operation conditions such as loss of phase and input of harmonic wave, is simple and useful, has the strong anti-jamming capability, and can rapidly acquire the phase sequence information of three-phase electricity.

Description

technical field [0001] The invention relates to the field of electricity, in particular to a three-phase electric phase sequence judgment method. Background technique [0002] In electronics, electric power, instrumentation, automatic control and power electronic equipment, it is often necessary to detect and judge the phase sequence of the three-phase AC power supply. If the phase sequence is wrong, it is necessary to form protection in time. Especially for equipment that only allows one-way rotation, if the phase sequence is wrong, it may cause damage to its rotating parts; for example, due to the change of the phase sequence of a passenger elevator, the running direction is opposite to the predetermined direction, which may endanger personal safety. Then it is necessary to take measures to detect the phase sequence. [0003] Early phase sequence detection is often composed of capacitors and resistors. Although the structure is simple, the capacitor value is large, the po...

AI Technical Summary

Problems solved by technology

The digital logic or single-chip microcomputer used in the existing phase sequence detection method has complex logic and is prone to misjudgment

[0004] In addition, the publication number is CN101320063B and the invention name is a three-phase AC phase sequence detection device and method, which needs to be calculated by angular frequency to determine the phase sequence direction of the three-phase AC power; the publication number is CN104459354A and the invention name is a three-phase AC power grid phase sequence detection The method and device need to calculate the amplitude of the positive sequence component of the three-phase voltage according to the two-phase rotation coordinates of the positive sequence component of the three-phase voltage, and calculate the positive sequence of the three-phase voltage according to the two-phase rotation coordinates of the negative sequence component of the three-phase voltage. The amplitude of the component; the calculation method is complicated by calculating the angular frequency or amplitude above, and the reliability of judging the phase sequence by this method is relatively low

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