Fast three-phase rectification missing phase detection and normal phase tracking method

Abstract

The invention discloses a fast three-phase rectification missing phase detection and normal phase tracking method. The method includes the following steps that: rectangular pulse signals of line voltage of three phases of supply voltage are obtained; the phase position of the rising edge of each phase is detected; whether the actual phase position of the rising edge of each phase is consistent with a corresponding actual phase position is judged, if the actual phase position of the rising edge of each phase is inconsistent with a corresponding actual phase position, a phase missing fault alarm is emitted; and finally, detected rising edges or the widths of phase intervals of any two phases of which the electric levels are identical are compared, so that phases of which the phase positions are identical can be obtained, and therefore, a missing phase can be identified. According to the fast three-phase rectification missing phase detection and normal phase tracking method of the invention, whether a phase missing fault occurs can be judged through judging whether phase positions at power supply voltage electric level signal change time points are normal; the missing phase is identified according to power supply voltage electric level change situations after phase missing; and a phase tracking counter is adopted, after the phase missing fault occurs, signals of phases which work normally are selected automatically as input, and therefore, the phase position of power supply voltage can be tracked normally before and after phase missing and in a phase missing process, and therefore, accuracy at rectification pulse control time points under normal and fault conditions can be ensured.

Description

technical field [0001] The invention relates to the field of rectification detection, in particular to a fast three-phase rectification phase loss detection and normal phase tracking method. Background technique [0002] In industrial production, the system block diagram of three-phase full-wave full-control rectification is as follows: figure 1 as shown, figure 1 It is a system block diagram of three-phase full-wave full-control rectification; the three-phase alternating current U, V, W passes through the protection and switching part, the rectification part, and then connects to the load. When a certain phase of the protection and switching part fails, the input rectification part will no longer be a complete three-phase power supply, and the subsequent rectification and load control strategies need to be changed in time to adapt to this change from normal power supply to phase-loss power supply. The principle of the three-phase full-wave full-control rectifier circuit i...

AI Technical Summary

Problems solved by technology

Taking the phase loss in interval 0 as an example, obviously, the phase difference from the fault occurrence point to the falling edge M is greater than 60°, so the phase loss determination delay time is greater than T / 6

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