Phase angle acquisition method and system

Abstract

A phase angle acquisition method and system. The method comprises the following steps: collecting a first-phase input voltage and a second-phase input voltage in a three-phase input voltage of a three-phase controllable rectification system; according to the first-phase input voltage and the second-phase input voltage respectively collected at two successive sampling moments, recognizing a phase sequence of the three-phase input voltage; when the phase sequence of the three-phase input voltage is a positive phase sequence, according to a first correlation between a voltage vector phase angle and the three-phase input voltage, acquiring a voltage vector phase angle θ(k) ＝ θ0 + ω*ΔT; and when the phase sequence of the three-phase input voltage is a negative phase sequence, according to a second correlation between the voltage vector phase angle and the three-phase voltage, acquiring a voltage vector phase angle θ(k) ＝ -θ0 - ω*ΔT. A voltage vector phase angle acquired thereby can be directly applied to a system control program, there is no need to perform fault-phase protection, and there is no requirement for the wiring of an input power voltage. The present invention effectively solves the problem that an existing phase angle acquisition method has relatively low intelligence, is inconvenient to apply and has low error-tolerant rate.

Description

technical field [0001] The invention relates to the field of three-phase controllable rectification, in particular to a phase angle acquisition method and system. Background technique [0002] In a three-phase controllable rectification or three-phase PFC (Power Factor Correction, power factor correction) system, in order to make the input current and input voltage in phase, most of the implementation methods, such as: dq decoupling double closed-loop control, sliding mode voltage The phase angle of the input supply voltage vector is required for control and hybrid nonlinear control, etc., so obtaining the phase angle of the input supply voltage is critical. [0003] Due to the phase sequence of the input power supply, there are two phase sequence relationships, one is UVW positive phase sequence (see figure 1 ), namely: e u =E m cosθ, e v =E m cos(θ-120°), e w =E m cos(θ-240°), e u is the phase u voltage of the input power supply voltage, e v is the v-phase voltage...

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Problems solved by technology

[0004] Based on this, it is necessary to provide a phase angle acquisition method and system for the problems of low intelligence, inconvenient application, and low error tolerance rate of the existing phase angle acquisition methods

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