The Research And Development Of Power Interruption Generator Based On VSC

The power interruption generator based on voltage source converter (VSC-IG) is an important instrument for researching power quality theory and testing compensation device. VSC-IG can not only generate many kinds of interruption voltage waveforms flexibly in theory, but also reduce the harmonics pollution to the grid. VSC-IG has practical significance on studying power quality problem.In this paper, the main circuit topology and basic principles of VSC-IG are discussed. The VSC-IG's operation principle and energy flow is introduced according to the ideal switching function of power transistor. The mathematical models of VSC-IG are established in at three-phase static abc coordinate system and dq's, whose characteristics are analyzed. The main circuit parameters are determined according to the target of power transfer capability, harmonic suppression, and dynamic response capability, which make use of mathematical analysis of circuit topology and the equivalent circuit as tools.For the stabilization of the DC side voltage, the power injected to VSC-IG from grid is controlled. The DC side voltage controller is divided into super stratum and underlying. Super stratum controller realizes the decoupling of dq-current by the theory of feedback linearization control method in the nonlinear differential geometry based on the direct current control method. A PI controller parameters setting method considering resistance parameters is proposed to optimize the controller's dynamic performance. The interruption voltage waves are generated, using SPWM rule sampling method as the underlying control strategy. Through ordering interruption function as modulated wave, the corresponding interruption voltage waveforms are got. A simulation model is build by using PSCAD / EMTDC platform, and the simulation study is carried out.In this paper, VSC-IG device is designed and implemented by making use of 30kW back to back converter physical device hardware platform in dynamic simulation lab. The hardware structure of device is introduced. The software based on DSP2812 digital controller is developed, and a set of human-computer interaction communication software is designed, both of which are applied to the VSC-IG successfully. The VSC-IG in this paper can generate many kinds of interruption voltage waveform steadily, and combined to the grid basically. The experimental results are good. The Main circuit structure and control strategy of VSC-IG are approved rightly, and the function of digital controller is also verified, which makes a basis for further research on power quality problems.