Bi-directional power flow alternating current-direct current transforming power supply in voltage-type alternating current-direct current-alternating current frequency converter

Abstract

The invention relates to a bi-directional power flow alternating current-direct current transforming power supply in a voltage-type alternating current-direct current-alternating current frequency converter, which has the technical characteristics that a basic circuit comprises a three-phase controlled bridge (CB), a three-phase line-incoming reactor X and a direct-current energy storage capacitor Cd, wherein the three-phase controlled bridge comprises six electronic switches, and each electronic switch in the three-phase controlled bridge comprises an insulated gate bipolar translator (IGBT) device or an integrated gate commutated thyristor (IGCT) device and an antiparallel fly-wheel diode. In the three-phase controllable bridge of the bi-directional power flow alternating current-direct current transforming power supply, the electronic switches adopt a control method synchronized with an alternating current line-incoming power supply instead of pulse width modulation and other closed-loop regulation. The bi-directional power flow alternating current-direct current transforming power supply has a simple controlling and debugging method and is safe and reliable to operate. A diode bridge (DB) can be added to satisfy the requirement that rectification power is more than feedback power. When the bi-directional power flow alternating current-direct current transforming power supply is applied, two sets or four sets of basic circuits can be connected in series / in parallel to work, forming 12 or 24 pulse wave rectification circuit to reduce harmonic wave.

Description

technical field [0001] The invention belongs to the technical field of voltage-type AC-DC-AC frequency conversion for motor control, and particularly relates to a bidirectional power flow AC-DC conversion power supply in a voltage-type AC-DC-AC frequency converter. Background technique [0002] Voltage-type AC-DC-AC inverters include two-level low-voltage inverters, neutral-point clamped three-level medium-voltage inverters, and H-bridge cascaded medium-voltage inverters, which have been widely used in the field of AC motor speed control transmission. Voltage type AC-DC-AC inverter usually consists of AC-DC conversion power supply and DC-AC inverter. When fast braking or placing a heavy object under a potential load, the motor is in the regenerative power generation state, and the mechanical kinetic energy or the potential energy of the heavy object will be converted into electrical energy by the motor and returned to the power supply. The voltage-type inverter allows bidir...

AI Technical Summary

Problems solved by technology

The main problems of this type of power supply are: high price (using IGBT or IGCT devices, large incoming reactance), troublesome control and debugging, which affect its application; If the frequency is low, the harmonics on the grid side will increase, and the effect will be compromised; in many applications, it is desired that the inverter power of the device is less than the rectification power, and this kind of power supply is difficult to achieve

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