Implementation of control signals of a three-phase inverter in real time using a unified PWM

Melnikov Dmitry Vladimirovich, Petrovichev Maksim Aleksandrovich

The article describes a voltage modulation method for high-efficiency voltage generation in a three-phase inverter powered by DC voltage. Considering the method of generating the voltage of the inverter, which consists of six power devices connected in parallel with a reverse diode, it can be found that the output voltage of the inverter is determined by the different voltages between each arm of the inverter and the duration of time during which different voltage is maintained. With optimal use of this time and duration of the strobing pulse, the task of voltage modulation can be greatly simplified, since the output voltage of the inverter is directly synthesized by the "effective time". In the proposed method of wide pulse modulation (PWM), the actual gating time for each arm of the inverter is calculated instantly and simply using the "effective time" displacement algorithm. In addition, by using a single degree of freedom that allows you to move the "effective time" to any location within the sampling interval, various carrier-based PWM strategies can be easily implemented without hardware modification. Consequently, almost instantly, the way the proposed scheme works can be changed to any carrier-based PWM strategy, such as sinusoidal PWM, space-vector PWM, and intermittent modulation schemes.

Keywords:control, signal, algorithm, pulse, pulse width modulation, inverter, reference voltage, gating, microcontroller.