Automatic identification method for terminal phase sequence

Abstract

The invention discloses an automatic identification method for a terminal phase sequence. The method comprises the following steps that 1, a basic electrical parameter voltage value u and a current value I when a terminal stably works are collected; 2, collected voltage and current signals are subjected to frequency domain decomposition to obtain base wave amplitude frequency characteristics of voltage and current; 3, the phase angle of a time moment corresponding to voltage and current waveforms in a base wave is analyzed, and whether or not the voltage and current are in the same phase sequence. According to the method, the three phase of the current and voltage can be judged just through a phase angle difference, and the method has the advantages of being simple, economical, easy to apply and popularize and the like.

Description

technical field [0001] The invention belongs to the field of electrical engineering, in particular to an automatic identification method for a terminal phase sequence. Background technique [0002] When electrical equipment such as electric actuators, excavators, and three-phase motors need to be reconnected to the power supply due to maintenance or work site transfer, it is inevitable that the phase sequence will be reversed, so that it cannot work normally; for equipment that only allows one-way rotation Said that it may cause damage to its rotating components; due to the change of the phase sequence of the passenger elevator, the running direction is opposite to the predetermined direction, which may endanger the safety of life. The early phase sequence detection circuit is composed of capacitors and resistors. Although the structure is simple, the capacitance value is large, and the indication of the indicator light is required. Detection, some of the existing phase seq...

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Problems solved by technology

[0004] At present, there is no literature that proposes an accurate, effective, and fast method for automatic identification of terminal phase sequences, and there is no frequency domain decomposition based on the collected voltage and current signals to obtain the fundamental wave amplitude-frequency characteristics of voltage and current, and analyze the voltage and current in the fundamental wave. The phase angle at the corresponding time of the current waveform, if the absolute value of the fundamental wave phase angle difference at the corresponding time of the voltage and current is less than 0.05 (radian), it is judged to be the same phase sequence, otherwise it is not the same phase sequence

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