Real-Time Harmonic Component Decomposition for LV Grids Using Heterodyne Method With Adaptive Moving Average Filters

Abstract

To achieve climate-neutral society, distributed generation (DG) based on renewable energy sources (RESs) as well as electrical mobility and battery storages will penetrate electrical energy network at medium voltage (MV) and low voltage (LV) levels. Smart measurement systems with high dynamic performance are required in order to extend operational management and real-time control features to the distribution system operator (DSO) level. This paper presents a real-time harmonic component decomposition method that is based on a new combination of the heterodyne method and moving average filters (MAFs) implemented using adaptive windows with trapezoidal integration and interpolation. An optimized implementation structure for field programmable gate array (FPGA) is also given. Simulation results indicate that the method can accurately decompose harmonic components even at off-nominal grid frequency. The developed algorithm is implemented in an FPGA device and tested using emulated and real grid signals. It can decompose voltages and currents up to eight signals each up to the 50th harmonic at the sampling rate of 40 kHz. The achieved performance with the low computational requirements highlights its benefits in measurement and control in DSO level.