Design Of The Operation And Control System Of The 320kV Forced Zero HVDC Circuit Breaker

In recent years, HVDC(high voltage direct current) technology has been emphasized and developed because of its distinctive advantages, while the fast breaking technology and the HVDC circuit breaker technology in high voltage and current situations have been the key problems which limit the development of the DC power grid. However, the studies of the HVDC circuit breaker are concentrated on the theoretical level all of the world, which are designing new circuit breaker topologies and verifying them through simulation and experiment. There are seldom studies about the test and control methods of the developed HVDC circuit breaker prototypes, which result in the HVDC circuit breakers cannot be used in engineering applications.To realize the engineering practicability of the 320 kV forced zero HVDC circuit breaker prototype, the operation and control system of it was designed in this paper. Firstly, the topology and principle of the circuit breaker was introduced in detail, on this basis, the components which should be controlled by the operation and control system were proposed. Meanwhile, the restrictions which effect the operation and control system during the control process were analyzed, upon which the objects should be monitored were proposed and the monitoring specifications were studied.Considering the controlling experience of AC circuit breakers and the particularity of DC circuit breakers, this paper proposed a design of separating the operation and control system into two levels, which are local control level and centralized control level. Then this paper designed the specific functions of the operation and control system, including the communication protocol between two levels, the operating mode of the system, the main functions and control flows of each level, etc. Thus there can be a relatively complete operation and control system of the forced zero HVDC circuit breaker.Finally, this paper designed a local level controller, the MCU of which is MSP430 of TI Corporation, and the peripheral design was according to the functional requirements of the local control level. The practicability and reliability of the controller was verified by the experiment aimed to proof the principle of the topology which was conducted on the unit prototype of the forced zero HVDC circuit breaker because the unit prototype operated successfully according to the command of the local level controller in the experiment all the time.