Delay Margin Computation for Load Frequency Control System With Plug-in Electric Vehicles

Impact of load sharing schemes on the stability delay margins computed by Rekasius substitution method in load frequency control system with electric vehicles aggregator

“…8 It should be mentioned here that only communication delays from EVs aggregators to EVs are considered in this study because the delays observed in the transmission of regulation signal from ISO to the conventional generators are less significant. [7][8][9][10][11] The primary reason for this assumption is that ISOs usually deploy the communication link between conventional generators and ISOs, independently. Also, communication delay requirements of the link are ensured by the ISOs themselves.…”

“…Step 2: The modified characteristic equation is obtained using Equation (10). The coefficients of the 15 th -order polynomial are presented in Appendix B for the selected parameters.…”

“…6,7 Despite the fact that the dynamic performance can be improved by integrating EVs into the LFC systems, the delays caused by the integration of EVs can rigorously affect the dynamics and stability of these systems. [8][9][10][11] The response time to the regulation command by Independent System Operator (ISO) is imperative in frequency regulation service. Normally, ISO transmits the commands every 2-6 seconds to the aggregator.…”

“…19 The frequency sweeping test was applied to the delay margin computation of a single-area LFC-EVs system. 10 The existing studies clearly show that the frequencydomain direct methods accurately determine stability delay margins of electrical power systems with communication time delays. However, the main disadvantage of these methods is that they can be used for only constant delay cases.…”

“…11 Stability delay margins in single-area LFC system having plugged-in EVs were determined by a combination of the binary iteration algorithm and frequency sweeping test by Khalil and Peng. 10 The frequency sweeping test also computes exact delay margin results. However, the selection of the frequency range for the sweeping test requires undesired computational effort.…”