Pulse Width Modulation of Three Phase Inverters Based on Linear Programming

Abstract

Traditional three-phase voltage-source inverters supplied by constant dc-link voltage usually utilize the space vector PWM to achieve maximum output voltage. This paper deals with optimization of inverter leg voltages using linear programming method. System definition is based on the relationship between the known voltage vector, which is demanded by an upper control loop and the unknown leg voltages which enter the carrier-based PWM block as modulation signals. A slack variable is introduced to the system as minimization objective, defining border for all leg voltages. Optimization procedure minimizes leg voltage maxima, and thus, the maximum utilization of the dc-link voltage is ensured. The theoretical assumptions have been verified by simulations as well as by experiments on laboratory prototype.

Development and Performance Evaluation of Integrated Hybrid Power Module for Three-Phase Servo Motor Applications

“…If the modulation index is larger than 1, the PWM inverter will operate in the overmodulation region, and the output voltage will still be clamped to ±V dc /2, resulting in a substantial decrease in the output AC voltage quality and DC bus utilization. Today, despite computational complexity and intensity, SVPWM is a more preferred and ideal PWM scheme due to benefits, such as its capability in potentially having a greater output voltage without distortion of the waveforms of the line-to-line output voltage, its low harmonic content, and its fixed switching frequency [ 39 , 40 ]. In order to improve its computational complexity and inefficiency, a simpler and more computationally effective SVPWM scheme has been developed through injecting a triangular zero-sequence signal to the sinusoidal waveforms (SPWM) to create non-sinusoidal modulation waveforms.…”