PWM (pulse-width modulation) interlocking drive circuit

Abstract

The invention provides a PWM (pulse-width modulation) interlocking drive circuit which is stable and reliable, lower in drive power, long in service life and fast in switching speed and comprises a digital signal processor which can be used for generating a PWM signal, wherein the digital signal processor has N pairs of PWM signal outputs and each PWM signal is connected with each pair of upper and lower bridge arms of a MOSFET (metal-oxide-semiconductor field effect transistor) module. The digital signal processor which is fast in operational speed and has a PWM signal generator is adopted as a drive core, the duty cycle and the output frequency of the PWM can be programmed by software; and PWM pulses of the upper and lower bridge arms of the MOSFET module are controlled to adjust appropriate dead time, so that the condition that the upper and lower bridge arms of the MOSFET module are not conducted is ensured; and meanwhile, the PWM can be connected to the upper and lower bridge arms of the MOSFET module through an interlocking circuit, namely that the PWM signals are not simultaneously input to the upper and lower bridge arms of the MOSFET module from the aspect of circuit, and safety of the MOSFET module is ensured.

Description

technical field [0001] The invention relates to the technical field of motor drive, and specifically designs a PWM interlock drive circuit. Background technique [0002] As one of the power semiconductor devices with the most application prospects in the motor drive system, the performance of the MOSFET module determines whether the motor drive system can work safely and stably. In the electric vehicle motor drive system, the most frequently encountered problem is the damage of the MOSFET power module (hereinafter referred to as the MOS module). In order to solve this problem, technicians have done a lot of research work on MOS module drive protection. The research found that the main reason for module damage is that the module is burned due to direct short circuit caused by simultaneous conduction of the upper and lower bridge arms of the same phase. [0003] At present, the driving method of the module has been used in many mature applications. The most common one is that...

AI Technical Summary

Problems solved by technology

The disadvantage of this driving method is that due to the existence of MOSFET parasitic capacitance, the MOSFET cannot be turned off immediately, resulting in the simultaneous conduction of the upper and lower bridge arms, resulting in damage to the MOS module.

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