Simulation Research On Dynamic Reactive Power Compensation System

A lot of complex electric power load(electrical railways,rolling mill,coal mine hoist,etc)in the network consumes a large number of reactive power and produces harmonic.It increases the power loss and reduces electric energy utilization.So the thesis is finished with the support of 2013 Hubei Technology project “key technology research of quickly dynamic reactive power compensation under complex electric power load”.Three-phase fully-controlled rectifier bridge with resistance inductance load is selected as the research object.The whole dynamic reactive power compensation simulation system is developed by using Matlab/GUI.With the simulation system,the system characteristic,such as the reactive power characteristics,harmonic characteristic,harmonic elimination,impedance of the IGBT type variable reactor and reactive power compensation effect,are analyzed.What have done and achievements obtained are as follows:(1)The simulation model of the dynamic reactive power compensation system is set up.According to the function requirement of the simulation system,the dynamic reactive power compensation simulation system and its subsystem is developed using Matlab/GUI.The subsystems are the reactive power characteristics subsystem,harmonic characteristics subsystem,harmonic elimination subsystem,impedance characteristic subsystem and reactive power compensation effect subsystem respectively.(2)Reactive power characteristics and harmonic characteristic are analyzed.The reactive power variation rule is confirmed by adjusting the pulse phase angle a from 0 degree to 85 degree with every 5 degree increment in the research object.The simulation data provides the parameter basis for the reactive power compensation.Taking a=70 degree,the simulation data,such as the harmonic current and reactive power data,lays the foundation for the following study.(3)The dynamic reactive power compensation is normal running after the harmonic is eliminated.When a=70 degree,the simulation data of the harmonic elimination subsystem is analyzed,and the parameters,such as LC filter,the harmonic current and the system reactive power,are obtained.(4)The carrier frequency in the simulation study of reactive power effect is determined by analyzing the impedance characteristic of IGBT type variable reactor.The relationship between equivalent impedance value of the IGBT type variable reactor and modulation ratio at different carrier frequency is analyzed.The suitable carrier frequency range is obtained to be 1000 ≤ cf ≤ 4000.(5)The parameter optimization and the reactive power compensation effect of the dynamic reactive power compensation device are completed.In the reactive power compensation effect analysis subsystem,the optimal program is designed to determine the optimal parameter.Modulation ratio is determined to be 0.7 and the compensation capacitance value is 120μF.The effect of the dynamic reactive power compensation is obtained and the designed optimization parameter is verified to be scientific and validity.In conclusion,an entire simulation analysis system is constructed.The optimal program is designed to determine the optimal modulation ratio and compensation capacitance value.The research provides theoretical support for the development of dynamic reactive power compensation device.