Magnetic Valve Controllable Reactor In Reactive Power Compensation

Firstly, the development history of reactor was introduced in this paper; the research achievements recently and the application of reactor were also mentioned in this paper. The basic theories of Magnetic-Valve Controllable Reactor (MVCR) were analyzed in chapter two. On the basis of state equations, the equal circuit equations were got, then using the software of MATLAB to construct emulate model. In chapter three, the characteristics of volt-ampere, control, harmonics and response were emulated, the curve of every characteristics were presented in this chapter. On the other hand, we analyzed the characteristics in the form of formulations. Then we compared two kinds of results to validate the veracity and validity of the model.On the basis of MATLAB emulation model, we discussed the methods of improving response-speed. From the point of hardware, increasing the tap-ratio of reactor, using direct current windings in addition or capacitance discharge were all in promotion. From the point of control strategy, we can use the way of increase conduction angle, but this method was just suit to conditions that the load wasn't full. In this paper a new kind method of increase tap-ratio was promoted, the DC control voltage becomes two times, while the range of conduction angle becomes 0~90 accordingly. This method has a perfect control characteristic, which was almost linearity. The disadvantage was that the active power consumed has a little increase, but not more than 10 percents. In the emulations of MATLAB, response time from zero to rating conditions was just 0.15s, the lower current of MVCR, the faster of the response speed.In chapter four, we also discussed the method of capacitance discharge to improve response speed. The problems of nonlinear inductance in control circuit, the optimal oscillation period and control strategy were all mentioned. The respond time can be condensed to 0.01 second by this way, so we can resolve the problem of low response speed of reactor thoroughly. But there were several problems need to resolve further more, such as the charge voltage is too high.In the last chapter, we applied the MVCR which response speed was improved to electrical railway; MVCR matched with fixed capacitance (FC) was used in reactive power compensation. In the aspects of compensation effects, response time, power factor and so on, we compared and analyzed the methods of promoted in chapter four. The results of emulation indicated the first compensation method can satisfy the demand in a certain extent, the last way can fully satisfy the demand, the dynamic compensation effects were ideal.