HVDC Light Control Technology And Its Realization

HVDC Light is a new-type HVDC based on Voltage Sourced Converters (VSC) Technology. As using IGBT in VSC, the current will be cut off easily; also the pulse-width-modulation (PWM) technology can be used for passive inversion. As a result, supplying to passive load with HVDC Light has being come true. The VSC technology has many more superiorities, such as small cubage, strong function, decreasing filter device and simplifying conversation structure. For these reasons, this technology is named HVDC Light. Besides the superiorities of traditional HVDC, HVDC Light can be used for supplying to the isolated and distanced load, economically transmitting power to center load and connecting separated sources. Also, the control method of HVDC Light is much more flexible and multivariate. The voltage drop in the transmission line will be decreased and the voltage quality will be increased by using HVDC Light technology.In this paper, the control method and its application of HVDC Light will be mostly studied. Firstly, the steady and dynamic model of HVDC Light and the DQ model of VSC are established. Then the structure of control system and the basic control method are introduced for designing VSC controllers. The VSC controller is based on dual-close-loop control strategy. For validating the VSC controller, the MATLAB simulation models are established. It is demonstrated by simulation results that the controller is convenient, flexible and efficient; moreover, the power flow and the stability of HVDC Light system can be controlled easily, all the basic control method can be achieved by this controller. At last, the protection strategy of DC line and VSC is discussed.The HVDC Light experiment system including its physical model, parameter of main circuit, hardware and software is designed based the control theory. In this experiment system, the IGBT Intelligent-Power-Modulation (IPM) is used as conversation, and DSP TMS30LF2812A is used to achieve control arithmetic. Based these designs, the low voltage principle debug is working in this experiment system. The result shows that the scheme is efficient, and most target of the experiment has been achieved. At the same time, some questions are discovered, and the corresponding solving schemes are present for further research.