Three-level half-bridge drive circuit and converter

Abstract

The present invention provides a three-level half-bridge driving circuit and a converter, comprising a system control unit and a half-bridge module, wherein the half-bridge module includes a signal processing unit, an isolation amplifying unit and a switch unit; the system control unit is used to generate the half-bridge module The required two-channel PWM signals; the processing unit is used for signal distribution according to the two-channel PWM signals to output four-channel half-bridge PWM signals; the isolation amplifier unit is used for controlling according to the four-channel half-bridge PWM signals The switch unit is turned on; when the signal processing unit detects the fault signal of the half-bridge module, it generates a four-way half-bridge PWM turn-off signal according to the fault signal and the two-way PWM signal, and the isolation and amplification unit is also used to The four-way half-bridge pulse width modulation turn-off signal controls the switch unit to turn off. The three-level half-bridge driving circuit and the converter provided by the invention can quickly respond to the fault of the half-bridge module and perform fault blocking, and have high reliability.

Description

technical field [0001] The invention relates to the technical field of energy supply, in particular to a three-level half-bridge drive circuit and a converter. Background technique [0002] The three-level circuit topology is developed from the two-level topology. Each phase of the neutral point clamped type (Neutral Point Clamped, referred to as NPC) is composed of four power switching devices and two power diodes connected in series. Three levels including 0 level. Compared with the two-level topology, the three-level topology can withstand only half of the two-level voltage, and has the advantages of low harmonics, low loss, and high efficiency. It has been used in the field of industrial and rail transit power electronic converter technology be applied and developed. However, due to the increased number of power switching devices to be controlled and the specific switching timing requirements, the control signal transmission, detection and processing are more complicat...

AI Technical Summary

Problems solved by technology

However, due to the large number of power switching devices that need to be controlled and the specific switching timing requirements, the control signal transmission, detection and processing are more complicated than the two-level topology.

[0003] In the prior art, each half-bridge unit of each phase receives four pulse width modulation (PulseWidth Modulation, PWM) signals from the system control unit. Due to its complicated wiring, the four pulse width modulation (Pulse Width Modulation, PWM) signals are susceptible to interference

Moreover, after the failure of a single-phase half-bridge unit in a multi-phase converter, the blockade of other half-bridge units needs to be completed by the system control unit, resulting in a long delay in the fault protection blockade, which is likely to cause failure of other half-bridge units. The flexibility and versatility of phase-half-bridge units in parallel and multi-cascaded half-bridge units are poor in circuit topology applications

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