Читать книгу Power Electronics-Enabled Autonomous Power Systems - Qing-Chang Zhong - Страница 42

Droop control plays an important role in PFR. The droop settings of individual participants specify the slope and the amount of the PFR. In a SYNDEM smart grid, VSMs associated with different types of suppliers and loads, according to their nature, can be configured with different droop coefficients addressing critical levels, economic benefits, frequency conditions, and other factors. For example, a wind generator may not be able to provide enough PFR for a low frequency condition but can easily provide PFR for a high frequency condition. It is normally not a problem to completely shut down heating, ventilation, and air conditioning (HVAC) systems for several minutes or to shift washing machine and dishwasher use by a couple of hours, even up to 24 h. For economic reasons, it is also possible to set a large droop, e.g. 10% for small frequency conditions and a small droop, e.g. 3%, for large frequency conditions. In this way, achieving the maximum PFR without significantly affecting the quality of service is possible in many cases. Moreover, shifting the peak load reduces the peak/normal load ratio and the PFR needed as well.