Hybrid filter for high-power converter systems

Abstract

This paper presents a digital hybrid filter which can be applied to power electronics control systems. The filter suppresses high-frequency noises while still providing a fast step response, its weighting algorithm is based on an open-loop criteria that analyses the discrepancy between an Infinite Impulse Response (IIR) and a Moving Average (MA) filter. The filter performance is compared to classical implementations through a step response and a Signal-to-Noise Ratio (SNR) analysis. The computational cost is also evaluated to verify its use on hard realtime systems. To evaluate the proposed filter, experiments were made on a microcontroller-based high-power frequency inverter with hard-time constraints, ensuring its applicability.