Zero common-mode voltage modulation and input reactive power control method of direct matrix converter

Abstract

The invention provides a zero common-mode voltage and input reactive power control method of a direct matrix converter, not only provides a space vector modulation method of the zero common-mode voltage of the direct matrix converter, but also provides a control method for controlling input reactive power on the basis of the modulation strategy. According to the modulation method, a clockwise rotation vector and an anticlockwise rotation vector are adopted at the same time, and expressions of the duty ratios of the vectors are given. The modulation method can achieve zero common-mode voltage of the direct matrix converter, common-mode current is effectively restrained, the service life of a motor is facilitated to be prolonged, and electromagnetic interference to surrounding equipment is reduced. According to the degree of freedom of the duty ratio in the modulation strategy, a control method for simply realizing input reactive power is provided. In addition, the control method provided by the invention does not need complex sector judgment; and the control method is small in calculation amount and suitable for practical application.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and more specifically relates to a zero-common-mode voltage modulation and input reactive power control method of a direct matrix converter. Background technique [0002] The direct matrix converter has been a research hotspot in the field of power electronics in the past ten years. It has many excellent characteristics, such as bidirectional energy flow, sinusoidal input and output currents, controllable input power factor, and no need for intermediate large-capacity energy storage links. Therefore, it has a wide range of applications in the fields of motor drive and wind power generation. [0003] However, matrix converters generate high frequency, high du / dt common-mode voltages at the neutral point of the motor load during operation. The common-mode voltage excites the stray inductance and coupling capacitance in the system, generates a large common-mode current, and generates elec...

AI Technical Summary

Problems solved by technology

However, the conventional modulation method using the rotation vector needs to judge the sector, and there are problems such as complex calculation and uncontrollable input power factor.

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