Inhibition method for starting impulse current in three-phase active rectifying circuit

Abstract

The invention discloses an inhibition method for starting impulse current in a three-phase active rectifying circuit. Each phase of series current limiting resistor and disconnecting switch of the three-phase active rectifying circuit are switched in a power grid, the current limiting resistors are connected with contactors in parallel; during normal operation, the contactors are closed for a bypass current limiting resistor; when the three-phase active rectifying circuit is started, the capacitor voltage on the direct current side reaches a set value, and the set value is greater than a single-phase power grid voltage peak; or, impulse current is generated. The phenomenon that the output current is uncontrollable caused by the facts that the boosting is limited when an uncontrolled rectification precharge manner is purely adopted and the output capacity of the device is limited; the voltage on the direct current side can be charged to a steady-state value required during operation accurately, and the voltage can be flexibly adjusted, and the voltage loop starting is facilitated.

Description

technical field [0001] The invention relates to the field of electric energy conversion, in particular to a method for suppressing the starting surge current of a three-phase active rectifier circuit. Background technique [0002] Traditional rectifiers are composed of uncontrolled diodes or semi-controlled thyristors, which generate distorted currents that cause grid pollution. At present, rectifiers often use fully-controlled power electronic devices combined with PWM modulation technology, which has the advantages of low harmonic content of grid-side input current and high power factor, and has become a research hotspot in the field of power electronics. In normal operation, the three-phase active rectifier circuit often adopts a double closed-loop control mode of the DC voltage outer loop and the inductor current inner loop. However, when starting, due to the low DC side voltage and the weak output capability of the AC side of the rectifier, a large inrush current will ...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the above-mentioned technical problems, the present invention provides a method for suppressing the start-up inrush current of a three-phase active rectifier circuit. This method raises the bus voltage on the DC side to the set value during normal operation before the device is started, fundamentally solving the problem of Inrush current problem

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