Tutorial “time averaging methods in PWM multilevel power converters analysis: Application to voltage quality evaluation and flying capacitors average voltage balancing dynamics”

• Time averaging is a powerful tool for multilevel converters analysis • Using time-averaging techniques, we obtained simple closed-form asymptotic voltage quality expressions for multilevel converters with an arbitrary number of levels and (odd) number of phases • Ripple voltage Normalized Mean Square criterion is related to iron core (eddy current) loss induced by power converter switching • Applied to FCC voltage balancing dynamics, time averaging methods delivered simple closed form expressions that reveal dependences on load parameters, switching frequency, capacitances, DC voltage command / AC modulation index, and modulation strategies • Time averaging methods are true analytical that stimulates engineering intuition and creativity and a good example is our simple elegant Flying Capacitor self-precharge solution - precharging capacitors using natural voltage balancing mechanism while keeping load current zero on average • Flying Capacitor Converter future research directions - accounting for other loss mechanisms (iron loss), improved (optimal) voltage balancing PWM strategies, generalization for 3- and multiphase converters and more