A novel real-time adaptive algorithm for harmonic detecting

This paper presents a novel adaptive harmonic detecting algorithm. For step change of load current, it can reduce the filter transient period to less than one fundamental cycle without affecting steady-state accuracy, and additional calculation is very little. The algorithm based on the analysis of transient behavior of adaptive weighting factors. It is proven that the expectation of weighting values converge exponentially with fixed time constant during transient period. The time constant is independent of system frequency and load current. So the steady-state weighting values can be estimated from the initiative variety of exponential curve. Simulation results verified theoretical analysis.