| It's very important to solve the problems of the power supplying system by getting many power parameters of high precision, low cost, portable and real time testing. Many researchers are now working hard on the testing of voltage's RMS ,current's RMS , electric power , reactive power , power coefficient ,and voltage's P-P value ,current's P-P value ,wave displaying and storing etc.This system's hardware design uses TMS320VC5402 as main controller that is a part of TI Company's 5000 serial DSP and is high quality and low prize. We use fast speed data memory and flash program memory extension in order to realize real time and high-speed digital signal process and system's program. In order to measure ac and dc current and voltage at the same time, this system uses resistance disport voltage method to sampling voltage and uses isolating amplifier to isolate and transmit signal. This system also use magnetism balance current mutual inductance sensor to get the sample of AC/DC current. In order to measure frequency accurately, on hardware circuit design a Smite variable threshold voltage comparer is used. LCD is used to show measured data and wave. Because the bus speed of LCD is low, flip-latch and interrupt is used to realize communication.Key arithmetic in system's software design is detailed in this paper. All arithmetic is based on data sampling, including square root of one cycle serial express virtual value of current and volt; square root of product of sequence of one cycle express the active power; The fft is used to harmonics analysis. The other difficult arithmetic is also used, including arithmetic of computing the power factor, arithmetic of computing frequency and so on.This system have reliable hardware and software support. It is proofed stable and reliable by practice. Measuring precision<0.3%, it can satisfy design demand, this system has every high application value.
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