A Demand Response Strategy in High Photovoltaic Penetration Power Systems Considering the Thermal Ramp Rate Limitation

In high photovoltaic (PV) penetration power systems, thermal units may be unable to cope with the large-scale power imbalance caused by PV reduction due to their ramp rate limitation. This paper formulates a demand response (DR) strategy to compensate for the timing imbalance between load demand and generation while avoiding high scheduling and operational expenses. First, the concept of the equivalent slope (ES) is proposed to measure the ramping speed of the net load curve and accurately quantify the DR aggregate power. Then, a DR strategy is proposed based on the ES and the thermal ramp rate limitation, in which the dynamic factor adjustment (DFA) increases the aggregate power by directly controlling the DR strategies, and the leading adjustment (LA) transfers part of the peak demand to other times when PV generation is abundant. Finally, simulation results verify the validity of the proposed strategy in maintaining the power balance while ensuring the comfort level of consumers.