Drive circuit suitable for silicon controlled rectifier of rectifier circuit of frequency converter

Abstract

The invention provides a drive circuit suitable for a silicon controlled rectifier of a rectifier circuit of a frequency converter, and relates to the technical field of circuits. A silicon controlled rectifier control circuit can control the on and off of a diode according to the phase of an input alternating voltage, a control panel performs signal control on the silicon controlled rectifier control circuit through an SOFT control signal, and an R-phase circuit, an S-phase circuit and a T-phase circuit are is integrally controlled by the silicon controlled rectifier control circuit, so that a silicon controlled rectifier gate level receives pulse driving voltage before sine-wave voltage passes zero, and heating caused by great loss generated by wave generation at high reverse voltage is avoided; the silicon controlled rectifier control circuit is used for controlling the S-phase circuit, the R-phase circuit and the T-phase circuit, a rectification soft start loop is formed by adding a diode, and the silicon controlled rectifier controls the on and off of the diode according to the phase of the input AC voltage, so that the loss of the silicon controlled rectifier is reduced, the production and assembly process of the product is simplified, and the cost of the whole machine is reduced.

Description

technical field [0001] The invention relates to the field of circuit technology, in particular to a drive circuit suitable for a thyristor in a rectifier circuit of a frequency converter. Background technique [0002] Under normal circumstances, the power grid needs to provide voltage to the motor of the electrical equipment, so that the motor can drive the electrical equipment to work; but for example, when the lifting equipment is lowered, the lifting equipment will drive the motor to rotate under the action of inertia, etc., resulting in The regenerative electric energy is fed back to the grid. In occasions where the mechanical load is relatively heavy and the braking speed is required to be very fast, etc., the regenerative electric energy generated by the motor is large, which may cause damage to the power grid or electrical equipment. Therefore, the braking resistor can be controlled by the inverter control circuit to consume the regenerative power electrical energy. ...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the deficiencies of the prior art, the present invention provides a drive circuit suitable for the rectifier circuit of the frequency converter, which solves the problems caused by the long-term use of uncontrollable rectification diodes and DC contactors as the rectification soft-start circuit of the frequency converter. installation complexity

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