Dsp-based Smart Meters

The measurement of the power of alternating current(AC) is mainly based on the power -convertor devised by analog multiplication unit or by digital multiplication unit in our country. The power–convertor with analog multiplication unit has a low precision and a poor stabilization, on the other hand, The power–convertor with digital multiplication unit has a high cost, but it does not mensurate the voltage , the current and the power of the AC at the same time. To satisfy even more the nicety, the precision the celerity and the Broad Band, we present a new theory and a new technology to contrive an intelligent power–convertor(IPC) based on DSP in order to overcome deficiency of the ammeter being used widely in our country. There are two CPU being used in this IPC, one of the CPU is TMS320VC5402 which carry out data processing, the other is Single Chip Micyoco which administers the IPC. Being used the technology of DSP, the IPC is not only a common intelligent apparatus(IA), but also it can do rapid multi-point sample and large numbers of real time. The IPC would restrain high harmonic widely. To sum up, our IPC has the merit of nine real-time, high measure precision and better anti-jamming and so on.The main work is included thereinafter three facet work:(1) The devised principle for intelligent apparatus and its excellenceFirstly, we discuss the devised principle of intelligent apparatus(IA) and its typical framework , secondly, the merit of the IA is discussed , finally, we discuss using the devised principle of the IA to the intelligent ammeter .(2) The realization of hardware and software for the intelligent ammeterThe function of the intelligent ammeter is analyzed and its devised framework is gained. The selection of kernel chip of circuit, the realization of prepositive circuit and the devise of data acquirement is discussed detailed. Moreover, the particular parameter of the kernel chip- TMS320VC5402 is given in our paper. The theory and the accomplishment of the FFT which is widely used in the analyze harmonic is discussed, moreover, we also discuss the window interpolation algorithm, the amended ideal sampling technology and the sampling PLL circuit. In the other hand, we revised the used algorithm and used the assembler of TMS320VC5402 to carry out the algorithm, we use the means of structure program to actualize the scanning program of key-press , the analyzing program of key-press and the controlling program of key-press.(3) error analyzing of The testWe expound the define and the sort of error and give the test reports and the error of our circuit , at the same time, the means of error compensated is brought forward based on the fundament of system error.The capability of our equipment satisfies our design through algorithm simulation, our equipment is able to measure the full harmonic of electric power, its precision grade is 0.05%. this is a new electric power meter which would be popularized.