Research on Coordinated Control Strategy of ITER Power Supplies and Reactive Power Compensation System

The stable operation of the ITER power supply is inseparable from the optimal control of the reactive power compensation (RPC, consisting of thyristor controlled reactor and turned filters) system. However, the traditional RPC control scheme with high latency can no longer meet the actual reactive power demand from the load side under the severe working conditions of the plasma control system. A new control law has been proposed and analyzed for RPC system based on the Lyapunov's theory by designing a Lyapunov function, which derivative is always negatively definite globally. With the help of the Lyapunov's asymptotic stability analysis, a new controller, which called Q Lyapunov-function-based control (QLC), has been designed to realize good dynamic performance comparing to the existed solutions. The simulation results show that the reactive power consumption of the grid side controlled by QLC has been greatly reduced during the transient change of the reactive power generated by the loads. Hence, the AC busbar voltage will have strong robustness. Moreover, it is also shown that the RPC system can be stabilized globally for handling severe signal disturbances.