Evaluation of aggregate models of plug-in electric vehicles for primary frequency control

Abstract

This paper summarises and evaluates in detail aggregate models of plug-in electric vehicles (PEVs) for primary frequency control (PFC) through dynamic simulations. A basic aggregate model of PEVs for PFC is introduced and then gradually developed in the following steps: 1) technical characteristics of PEVs are incorporated into the model; 2) technical characteristics of distribution networks are formulated and added; 3) a strategy is described to well-design the frequency-droop controller of PEVs for PFC. Moreover, from an economic point of view, a method is presented to assess the benefits which could result from PEVs for PFC. Four simulation scenarios are defined to evaluate the impact of: 1) different PEV's penetration levels; 2) PEV's operating modes and constraints; 3) power consumed in the network during the PFC; 4) well-designed frequency droop controller, on the frequency response following a contingency event. Simulation results show that aggregate PEVs have a great potential not only to improve the frequency response, while preserving the overall stability, but also to save some costs associated with PFC.