Wind Farm with HVDC Delivery in Inertial and Primary Frequency Response

Abstract

In this chapter, investigation of wind farms with line commutated converter (LCC) HVDC delivery in system frequency response participation is carried out. While LCC-based high power HVDC is a viable choice to deliver large-scale wind power, the consequent responsibility of such wind energy systems in frequency response should be assumed. A coordination control strategy for wind farms with HVDC delivery for participating in inertial response and primary frequency control is discussed in this chapter. The coordination philosophy is to feedback the grid frequency and its derivative and adjust the delivery power of the HVDC link according to the feedback signals. The feedback loop employing the derivative of the grid frequency aims to improve the inertial response while the feedback loop employing the grid frequency deviation introduces a droop at the rectifier control loop. When the grid frequency is too high or too low, active power flow through the HVDC link will be ramped down or up. In turn, the wind generation will increase or decrease the blade angles to reduce or increase the captured wind power through pitch control. A case study demonstrates the effectiveness of the inertial enhancement and frequency droop in HVDC control. Simulation results in TSAT are given.