Harmonic Energy Measurement Algorithm And Its FPGA Implementation

With the rapid development of power electronics technology, a large number of electrical equipment non-linear characteristics run into the power grid. Large amount of harmonics which appear in the power grid have caused the harmonic pollution in the power system, and they also seriously affect the accuracy of electrical energy measurement at the same time. The purpose of studying the harmonic energy measurement algorithm is to achieve the precise harmonic analysis, and the accurate measurement of the harmonic energy. It can provide a reliable basis for the scientific management of electrical energy.In this paper, harmonic energy measurement algorithms existing in domestic and international are introduced firstly. Windowed interpolation FFT algorithm and wavelet packet decomposition algorithms used frequently were researched. On this basis, a harmonic energy measurement algorithms based on dedicated digital filter have been put forward, which is more suitable for ASIC implementation.In this paper, a dedicated digital filter module was designed, which can meet the needs of the algorithm. The amount of computation and storage capacity of the algorithm were estimated, and was compared with the amount of computation and storage capacity of FFT algorithm Reactive energy measurement system design energy measure based on the Hilbert digital filter. The design of reactive energy measurement system is based on active measurement system, but it requires a Hilbert filter additionally. In this paper two Hilbert digital filter design methods were studied, and the corrugated cut Chebyshev method which has better effect was chosen to design the Hilbert digital filter. In MATLAB platform, dedicated digital filter module, Hilbert digital filter module, active energy measurement system and reactive energy measurement system simulation were simulated, and conclusions were get.In this paper Cyclone II series EP2C35F672C8target board of FPGA chips of Altera Corporation was chosen to implement the design. The way of the implementation of the dedicated digital filter module is that using DSP Builder to build a model in MATLAB platform and automatically generating the VHDL code. The way of the implementation of Hilbert digital filter module is that using the FIR IP core which provided by Altera Corporation FIR IP cores. The two modules are verified in hardware.Finally, achieve the harmonic energy measurement system on FPGA chips, and verify the system by using non-sinusoidal signals. Discuss and analyze the results, and find the sources of error and the methods used to improve the measurement accuracy.