Development Of New Reactive Power (harmonic) Sensor

This project realizes the ultimate objective is making use of the complex theory of the instantaneous reactive power, the AC signal sampling technique, the digital signal processing, for designing low-cost product, so the majority users can accept the product.After the RMS of voltage and current, the phase angle in the early and the phase difference was extended for instantaneous value, we can build up a unified theory of mathematical description about the instantaneous reactive power and the traditional power, for revealing the relationship between the two. Three-phase circuits instantaneous reactive power theory relating to the above was extended to the concept of transient value, which let active and reactive power to be extended amount of instantaneous, it was natural expansion of the traditional three-phase power circuit's theories. And the traditional theory of power was a special case of instantaneous reactive power theory when the three-phase circuit was steady-state.Digital filter performance and computing requirements are often contradictory, because of the development of low-cost requirements, we use long-integer computing, do not use floating-point operations, in order to use the ARM7 core to achieve. It need extremely high performance for algorithm. The method of verification is very important, a tool often can not meet our requirements. We were using matlab, C language, and excel on all aspects of the algorithm verification, and the result is reliable and satisfactory.The author has used the ARM+ADC architecture in this project, completes all hardware circuit's design, and mainly devotes to the following several aspect work: 1) high speed ARM+ADC architecture design and application; 2) high speed, highly effective theory algorithm research about theory of the instantaneous reactive power.Prototype isolate and acquire three-phase voltage and current in three-phase unit, by bus RS485 output measured three-phase AC active energy (polar), reactive energy (polar), active power (polar), reactive power (polar), apparent power, power factor (polar), frequency, the RMS of voltage and current, 1-19 harmonics of three-phase voltage and current ,The positive sequence, negative sequence, zero-sequence value of the voltage and current, with three-phase PWM output reactive power and harmonic currents.Prototype has passed the voltage isolation tests, high and low temperature tests, aging tests, as well as electricity for a long time, are not unusual. In the prototype reliability, safety meet the design requirements. Experience can be normal Certification, to meet the requirements of use.