This paper proposes a coordination control strategy participating in frequency control for the system interconnected by voltage source converter based high-voltage direct current (VSC-HVDC) inverter station and line commutated converter based high-voltage direct current (LCC-HVDC) rectifier station. The strategy includes active power and reactive power coordination control for VSC-HVDC and LCC-HVDC. The active power coordination control can improve the frequency stability of VSC-HVDC transmission network by reasonable switching additional frequency controllers. The reactive power coordination control can reduce the number of switching filters of LCC-HVDC and improve the voltage stability of power network during frequency regulation. Finally, an equivalent simplified model of practical grid is built in MATLAB/Simulink, and the effectiveness and adaptability of the additional frequency coordinated control strategy are verified by simulation.

VSC-HVDC;LCC-HVDC;frequency control;coordination control