High Voltage Regenerative Converter and the Control of Its PWM Rectifier

Abstract

In this paper is presented the structure and working principle of the cascaded H-bridge multilevel converter with PWM rectifier and phase-shift transformer. Using the leak inductance as the filter reactor of the PWM rectifier can reducing the volume and cost of the converter; the phase-shift secondary side of the transformer can eliminate the current harmonics caused by the single power unit, restraining the grid side harmonic especially the low order harmonic. In the control scheme PLL is employed to track the grid voltage's phase and frequency. The PIR control strategy of the PWM rectifier is to maintain the DC-link voltage stable when feeding the singlephase inverter. In this paper is introduced the mathematic model of the PWM rectifier, its control method and the PIR current control strategy. The waveforms and their spectrums are analyzed through experiments on a prototype testbed. The experiment results verify that the converter can achieve the regenerative ability when operating in the accelerating and decelerating of electrical machines and have a great value in industrial applications.

Finite Control Set—Model Predictive Control with Non-Spread Spectrum and Reduced Switching Frequency Applied to Multi-Cell Rectifiers

“…To compute the phase shift angle α, a mathematical characterization is necessary for the transformer's secondary currents; thus, references of the input current waveforms of the AFE rectifiers will be obtained [15]. The characterization is performed only for phase a; however, it is valid for phases b and c.…”

“…The third modification to this topology is seen in [14], where it is proposed to cancel the low-frequency harmonics by generating a switching pattern and transformer phase shift, achieving an input current with 23rd and 25th harmonics. Finally, a modification made in the rectifier stage is the use of AFE rectifiers; the novelty is using a PIR controller to manipulate the input currents of these rectifiers [15]; despite this, the multipulse transformer is still needed. From the point of view of high-power rectifiers [16], a multicell rectifier with low switching frequency is presented, which seeks to be friendly to the electrical network.…”

Finite Control Set—Model Predictive Control with Non-Spread Spectrum and Reduced Switching Frequency Applied to Multi-Cell Rectifiers †

“…The third modification to this topology is seen in [14], where it is proposed to cancel the lowfrequency harmonics by generating a switching pattern and transformer phase shift, achieving an input current with 23rd and 25th harmonics. Finally, a modification made in the rectifier stage is the use of AFE rectifiers; the novelty is using a PIR controller to manipulate the input currents of these rectifiers [15]; despite this, the multipulse transformer is still needed. From the point of view of high-power rectifiers [16], a multicell rectifier with low switching frequency is presented, which seeks to be friendly to the electrical network.…”