A single-cycle three-phase six-switch power factor correction pwm modulator

Abstract

The invention discloses a single-cycle three-phase six-switch power factor correction PWM modulator, comprising: an error amplifier, an integrator, a reset clock signal generator, a capacitive coupling DC blocking circuit, an inverting amplifier and a PWM modulation circuit; The two input terminals input the reference voltage and the sampling voltage respectively, the output terminal of the error amplifier is connected to the inverting input terminal of the integrator, the reset terminal of the integrator is connected to the output terminal of the reset clock signal generator, and the output terminal of the integrator is connected to the capacitive coupling isolation DC circuit, the output terminal of the capacitively coupled DC blocking circuit is connected to the inverting input terminal of the inverting amplifier, and the non-inverting input terminal of the inverting amplifier is grounded; the different input terminals of the PWM modulation circuit input the output voltage of the inverting amplifier, the three-phase input, and Reset the clock signal and output the PWM drive signal. In the present invention, the integral parameter τ of the integrator does not need to be strictly matched with the operating frequency, and at the same time, the influence of the temperature characteristics of components can be eliminated.

Description

technical field [0001] The invention belongs to the technical field of AC-DC converters of electric energy conversion devices, and more specifically relates to a single-cycle three-phase six-switch power factor correction PWM modulator. Background technique [0002] With the wide application of power electronic technology, the hazards of grid harmonic pollution have attracted more and more attention. The harmonics generated by equipment connected to the grid have greatly endangered the safety of the grid. Other equipment cannot work normally, or even cause equipment damage. These serious consequences force people to have higher and higher requirements for the total harmonic distortion (THD) of the input current of the power conversion device and the input power factor (PF). Therefore, the power factor correction of electrical equipment has always been a topic of great concern in the industry, and will definitely pay more and more attention in the future. In the power factor...

AI Technical Summary

Problems solved by technology

It is required to have a strict fixed relationship between the two, which means that a working frequency can only correspond to the integral parameter τ of a specific integrator. Once the working clock changes, the integral parameter of the integrator must change accordingly, otherwise it will Sawtooth wave is asymmetrical in positive and negative, or flat top occurs, resulting in large distortion

Because in practical application, the integral parameter of the integrator is determined by the integral resistance and the integral capacitance. Due to the temperature characteristics of the components, the operating frequency and the integral parameter will drift, and it is impossible to achieve a complete match.

And it is also necessary to fine-tune the maximum output of the integrator to be strictly equal to the input voltage of the integrator, so as to satisfy the restriction condition τ=0.5*T s , which is very cumbersome and time-consuming, so it will inevitably affect the effective application of the technology

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