The Calculation And Analysis Of Reactive Power For Power Grid With Power Electronic Devices

In AC circuit, because inductor and capacitor elements leaded into, power factor appears and then produces active power,reactive power and apparent power. Reactive power is regarded as energy conversion between power source and load. But with the wide application of power electronic load, the definition of reactive power has not simply been regarded as energy conversion between power source and load.The article through to the introduction of research status on the circuit reactive power in the domestic and foreign, and using the existing theory by power analysis and calculation, understanding the advantages and disadvantages of the existing theory, provides a theoretical basis for follow-up study. Through to the sinusoidal AC circuit reactive power case presentation, provides contrast to the study of power electronic load circuit reactive power. Changing the tradition mode, use the voltage and the current effective value and equivalent circuit method to simplify the circuit analysis course, put forward power electronic load conditions of power net reactive power definition and relation expressions, and carries on the corresponding engineering calculation.The article mainly includes the follow aspect1. Introduce the different of sinusoidal AC circuit and nonlinear load circuit in reactive power definition, introduce the basic ideas and the advantages and disadvantages of the existing theory.2. Provide a new definition for circuit power, that consist of three power form in the circuit: apparent power, active power and reactive power, through analyze single phase power electronic load circuit, providing power definition based on the effective value and forming power expression.3. Use several classic reactive power theory and new definition to analyse the power of the typical power electronic devices circuit, calculation and comparison, and compare these theory.4. Using experiments to prove the new theory, then forming a conclusion.