Three-phase three-wire phase voltage detection method

Abstract

The invention relates to a three-phase three-wire phase voltage detection method, which can accurately restore phase voltage effective value according to line voltage real-time collected data through the steps of wire-to-phase algorithm, phase lock and reference voltage construction, amplitude separation and amplitude reconstruction and the like. The method can realize phase voltage detection of an unbalanced three-phase three-wire system, and can even realize out-phase detection of the three-phase three-wire system; and the method is simple and practical and high in anti-interference performance, and can obtain phase sequence information of three-phase power quickly.

Description

technical field [0001] The invention relates to a phase voltage detection method, in particular to a three-phase three-wire phase voltage detection method. Background technique [0002] The grid voltage sampling of the grid-connected inverter adopts the line voltage sampling, and then uses the sampled line voltage as the value to determine the grid voltage response. This method can accurately respond to the grid when the three-phase voltage balance changes, but when When a single phase or two phases change, the actual sampled line voltage does not change linearly in accordance with the set phase voltage, so it does not meet the requirements of any phase specified in the standard. [0003] However, from a theoretical point of view, under the condition of unbalanced three-phase voltage input, due to the absence of the neutral line, the zero-sequence voltage in the sampled voltage data cannot be detected, so it is impossible to accurately recover the phase voltage from the thre...

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Problems solved by technology

[0002] The grid voltage sampling of the grid-connected inverter adopts the line voltage sampling, and then uses the sampled line voltage as the value to determine the grid voltage response. This method can accurately respond to the grid when the three-phase voltage balance changes, but when When a single phase or two phases change, the actual sampled line voltage does not change linearly in accordance with the set phase voltage, so it does not meet the requirements of any phase specified in the standard

[0003] However, from a theoretical point of view, under the condition of unbalanced three-phase voltage input, due to the absence of the neutral line, the zero-sequence voltage in the sampled voltage data cannot be detected, so it is impossible to accurately recover the phase voltage from the three-phase line voltage sampled data results. Voltage value

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