Phase shift control method and device for ePWM module and storage medium

Abstract

The invention provides a phase shift control method and device for an ePWM module and a storage medium. The ePWM module generates a first PWM signal and a second PWM signal, executes a first switchingoperation of a high-level signal and a low-level signal when the timer value of a timer is matched with a first comparison value, and executes a second switching operation of the high-level signal and the low-level signal when the timer value is matched with a timer period value. When a target phase set value is configured such that a phase difference is converted between a lag phase and a lead phase and when a previous phase set value of the timer is located in a first interval defined between an initial value and the first comparison value and the target phase set value is located in a second interval defined between the first comparison value and the timer period value, the second comparison value between the initial value of the timer and the previous phase set value is set so that the ePWM module executes a third switching operation of the high-level signal and the low-level signal, which is the same as the first switching operation, when the timer value is matched with the second comparison value.

Description

technical field [0001] The present disclosure relates to signal driving, and in particular to a phase shift control method, device and storage medium for an enhanced pulse width modulation (Enhanced Pulse Witdh Modulation, ePWM) module. Background technique [0002] The ePWM module used to generate PWM signals to drive electrical devices can succinctly implement a phase-shift control method such as PWM driving between bridges, where the phase shift includes lag phase shift and lead phase shift. Each complete PWM channel in the ePWM module consists of two PWM signal outputs, called PWMxA and PWMxB. The PWM signal of each channel establishes a synchronization mechanism through a synchronization signal. A major advantage of the ePWM module over ordinary PWM modules is that the phase difference between the PWM signals in each channel can be controlled by directly configuring the phase register, and the phase shift can be easily realized. [0003] However, the ePWM module is re...

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Problems solved by technology

[0003] However, the ePWM module is restricted by the phase shift mechanism when performing phase shift control. When the phase of the PWM signal crosses from a lagging phase to an advanced phase, or from an advanced phase to a lagging phase, there is a problem of waveform loss under certain circumstances.

Part of the waveform loss during phase shifting will cause the duty cycle of the PWM signal output to change, resulting in a DC bias in the periodically changing operating current, which will adversely affect the circuit components of the power device in particular.

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