PWM Strategies for VSIs: Analysis, Simulation with Python, Verification, and Practical Deployment on Modern Microcontrollers

Inhalt:
This paper presents PyPWM, a Python-based framework developed for the development, analysis, simulation, deployment, and verification of PWM strategies for Voltage Source Inverters (VSIs) on hardware platforms. PyPWM supports detailed waveform visualization, qualitative and quantitative calculations and comparative analysis. PyPWM can operate in three modes: (1) analysis, comparison, and tabulation of key parameters; (2) practical deployment by calculation of programmable timer values for embedded controllers and transferring them to a digital inverter board for rapid prototyping; and (3) serving as a data logger and validator when the embedded controller independently generates PWM through similar FW written in ‘C’. The framework is validated through simulations and experiments using common PWM strategies such as Sinusoidal PWM (SPWM), Third-Harmonic Injection PWM (THIPWM), Space Vector PWM (SVPWM), and Discontinuous PWMs (DPWM). Results include metrics like output voltage, load current modeling, Total Harmonic Distortion (THD), and the impact of dead-time and common- mode voltage (CMV) across various modulation indices and switching frequencies. Experimental validation was conducted on a 2-level VSI controlled by a 32-bit ARM Cortex M4 microcontroller with a CORDIC math unit, connected to the PC executing PyPWM via serial communication The results demonstrate the framework’s effectiveness in bridging theory and practice, accelerating the design process from simulation to real-time implementation.