The Development Of Motor Testing Instrument Based On DSP

Test is one of the important links in electric machines'producing and using. It is necessary to employ advanced technologies and measures to ensure high quality .With its hardware resources and speed limit, the conventional testing instrument only gains a small quantity of hits each cycle, so its precision isn't high. The conventional testing instrument cannot get these parameters such as harmonics and sequence component because of algorithmic restrict, which limits its application domain. Digital Signal Processor has rich hardware resources, which simplifies the design of hardware circuits. And DSP can implement fast math operation to digital signals, its operation capability has an advantage over the common processors. These math operations involve not only the simple plus, minus, and multiplication operation but also the function of signal analysis such as Fast Fourier Transform (FFT) and Discrete Cosine Transform (DCT). The motor testing instrument introduced in this dissertation is based on Digital Signal Processor TMS320F2812. TMS320F2812 can realize the simultaneous sampling to the voltage and the current in phase of motor. External Interface of TMS320F2812 can access up to 1M total memory. The programmable wait-state, chip-select and programmable strobe timing enables convenient interface to color LCD. Rich hardware resources and efficient analysis capability of TMS320F2812 can solve the problems about the bad real time performances, low precision and no harmonics analysis in the common instruments. This instrument is designed to measure, compute and analyse the triphase voltages and currents, without mechanical characteristic, temperature, noise and magnetic field etc. The dissertation specifies the compute principle of the parameters including AC frequency, voltage, current, active power, power factor and harmonics component, and so on. Then the hardware and software design of the testing instrument based on TMS320F2812 are provided. The design of LCD interface circuit provides a successful example for TMS320F2812 External Interface application. The instrument has passed the experimental validation. Experiment results show this testing instrument can not only measure and count the parameters including AC voltage, current, power, power factor and so on, but also implement harmonics analysis and display the waveforms. TMS320F2812-based testing instrument for motor's parameters realizes higher precision, high real time performance and efficient harmonics analysis, so it provides a effective solution for motor testing.