Researh On Voltage And Reactive Power Control Stratage Based On The Saturation Characteristcs Of Transformer

With the development of renewable energy,construction of UHV power grid and the application of submarine cables, the most important issue is how to ensure the stability of the power system.Reactive power balance is the basis of power system stability.This requires the reactive power compensation device is more stable,more real-time,high reliability.This paper proposes a controllable magnetic reactive power compensation function of the saturation control transformer.The transformer not only can transmit active power, but also can conduct continually reactive power compensation as magnetically controlled reactor. This has important research value.This article proves the controllablity of transformer as the inductive reactive power source based on the saturation characteristics of transformer,used a DC power to control the transformer core saturation level. Refer the iron core electromagnetic characteristics, study on the basic principle of transformer magnetizing reactance control, and deduced the mathematical model of controllable excitation reactance.According to the harmonic content of the transformer magnetic saturation problem,splitting the primary side of the transformer iron core enables significantly reduce of the harmonic content.Refer the control method of magnetic control reactor combined with the power transformer output constraints,study the control method of the excitation reactance of the transformer, and then establish the mathematical model for the control of transformer magnetizing reactance. Design the control system of transformer excitation control, mainly includes the detection part, the excitation current control part and driving part, in order to to control the degree of saturation of the transformer according to the corresponding control strategy. Changing the reactance value in order to achieve continuous reactive power compensation.