Brake device and brake method of AC-DC-AC traction transmission system

Abstract

The invention provides an AC-side brake device and brake method of an AC-DC-AC traction transmission system. The AC-side brake device of the AC-DC-AC traction transmission system comprises a thyristorphase control rectifier, an inductor, a resistor, a DC voltage detection unit, a motor current detection unit and a controller. The method comprises the steps of connecting the thyristor phase control rectifier to a three-phase output end of an inversion module, and connecting the inductor and the resistor which are connected in series to an output end of the thyristor phase control rectifier; and sending a DC-side voltage and a motor current which are obtained by sampling to the controller, respectively outputting a pulse signal and a phase control angle signal to the inversion module and the thyristor phase control rectifier by the controller through a control algorithm, and controlling a three-phase AC motor to run by the inversion module. By the device and the method, a four-quadrantrectifier is not needed, breaking can be achieved at an AC side, and the AC motor is in a controllable brake state; and when the device is applied to a cascaded H-bridge traction transmission system,a brake unit is unnecessary to be additionally arranged at each H-bridge power unit, only the brake unit comprising the thyristor phase control rectifier, the inductor and the resistor is needed to beadditionally arranged at an input end of the motor, and energy consumption braking is simple and practical.

Description

technical field [0001] The invention relates to the field of motor transmission and power electronics technology, in particular to an energy consumption braking device and a braking method for an AC motor working under regenerative braking conditions in an AC / DC / AC traction drive system. Background technique [0002] AC-DC-AC traction drive systems are widely used in industries, such as steel, petroleum, textile, rail transit and other fields, and the power range of their applications is also very wide, ranging from several kilowatts to megawatts. The vast majority of AC-DC-AC traction drive systems use voltage-type converters. The main structure of the traction drive system is as follows: figure 1 shown. The primary side of the transformer 11 is connected to the power grid, and the secondary side is connected to the rectifier 12. The rectifier 12 converts the three-phase alternating current into direct current. The direct current side of the rectifier 12 is connected to th...

AI Technical Summary

Problems solved by technology

This braking method cannot guarantee the stable braking of the motor when it is connected to the main circuit and operates normally.

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