Wind Farms With HVDC Delivery in Load Frequency Control

This letter develops a coordination control strategy for wind farms with line commutated converter (LCC) based HVDC delivery to participate in load frequency control. The coordination philosophy is to let the HVDC rectifier sense the grid frequency. If the grid frequency is too high or too low, active power flow through the HVDC link will be ramped down or up by introducing a droop at the rectifier control loop. In turn, wind generation will increase or decrease the blade angles to reduce or increase the captured wind power. This will be done by wind generation pitch controllers. A case study demonstrates the effect of the frequency droop in HVDC control. Simulation results in TSAT are given.