Economic and operational advantages provided by REGs for distribution systems include the following: power
balance during peak demand, decreased occurrence of power interruptions and system outages, reduction in
investment and operational costs due to flexible capacity and installation, as well as decreased dependence on
imported fossil fuel [2]. Despite these advantages, the increasing use of scattered and time-varying hybrid REGs can
result in a bidirectional power flow, which may either improve or worsen power quality, protection and stability.
These effects, especially with high penetration of REGs heavily rely on the characteristics of each installation and
specifications of the distribution system. Therefore, a distribution system must be continually monitored for
satisfactory levels of power quality [3]. Electric vehicle (EV) technology and electric vehicle charging stations
(EVCS) are rapidly being developed to reduce oil dependence and minimize greenhouse gas emissions. The
influence of EV and future EVCS on system performance highly depends on the charging scenario and the ability of
power utilities to deliver the required power to EVCS regardless of loading conditions. This dependence is due to
the time variability of electricity use by EVs [4].
Accurate assessment of the possible impacts of large grid-connected REGs and EVCSs on network performance
before installation is crucial. Performing such analysis is important so as to allow power utilities to become
efficiently equipped to solve potential operational issues caused by REGs and EVCSs. Numerous studies have
focused on steady-state modelling as well as the analysis of a single REG and its impacts on the system [5].
However, studies on the effects of high penetration REGs on dynamic operation and control of the system before
real-time implementation have scarcely been reported. This paper aims to analyze accurately the dynamic effects of
high penetration hybrid REGs and EVCSs on the power quality performance of distribution systems. To address the
practical aspects, the required data on weather conditions, EVCS loading conditions, and REG modelling were
obtained from the Malaysian Meteorological Department [6]. The REG data were obtained from various power
system manufacturers such as SunPower, Sanyo, General Electric, and FuelCell Energy. Simulations using the
MATLAB/Simulink software were conducted on a modified radial 16-bus test system installed with distributed
EVS, WT, PV, and FC units to study the effects of hybrid REGs and EVSs on system performance under various
weather and loading conditions.