Frequency measurement methods and impact in presence of frequency responsive loads and distributed energy resources

Frequency monitoring on the power system is used to balance load and generation, as load increases the frequency value decrease and as generation increases the frequency values increases. Under normal operation the frequency is maintained between 59.98Hz and 60.02Hz in a 60Hz system. Today the balance between load and generation is achieved by controlling generation only [1]. However, as more load control is being introduced to the power system, using the frequency value to turn on and off frequency responsive loads present a mechanism to provide regulation as well [2]. This method relies on local frequency measurement and local trigger set point. This paper illustrates the impact of frequency measurement on frequency responsive load application and on protection devices in presence of distributed generation.