Implement Of Harmonics Dectection Instrument With DSP Based On Wavelet Transform

With the development of electricity and electric power industry , the power harmonic become more and more important. It is very constructive to get power harmonic parameter in time.In this paper, It study the power harmonic parameter arithmetic in difference . Through wavelet transform,the break time in the temporary state can be found and the fundamental current is separated from power current in Matlab. It research harmonic measure in particular and introduce the wavelet transform theory based on the instantaneous reative power, the simulation shows that through this method the total harmonic current in power system is achieved.On the same time, It design a new power harmonic detection system. The system is composed by MCU and DSP, It use chip AT89C51 made by Ateml, Using MCU to controll the system ; It use chip TMS320VC5402 made by TI, Using DSP to collect power data and process them with wavelet transform. It design and realize muticenter sampling and conversion circuit. The communication between A/D and DSP adopt the DSP of MCBSP, the communication between MCU and DSP adopt DSP of HPI. in the wavelet designing. It design MCU and DSP system software, using c and asm to realize power harmonic measure in CCS. It compare two kind of the realization method based on DSP, The convolution algorithm has decreased the error using wavelet transform to decompose and reconstruct the signal, the harmonic and reative current can be computed with the algorithm in CCS. Emulation and debugging having been in progress to the convolution algorithm and DSP system procedure in CCS, the system have realized the required function.The new system has strong data process ability. It also can be improved easily and get deal with human friendly. Especially if it connect with the SVG, it can give harmonic and reative current to the SVG So it is suitable to domestic market. It is sure to be applied widely.