Proportional Derivative and Proportional Integral Derivative Controllers for Frequency Support of a Wind Turbine Generator in a Diesel Generation Mix

Abstract

The levelized cost of electricity production is highly dependent on the cost of fuel oil on the world market. In order to reduce the dependency on the fuel oil, many countries are adopting an energy transition towards distributed generation. Distributed generation can be described as various means of generating electricity at or near where it will be used. Such generating mode can be a solar PV system, wind turbine generator and other renewable energy sources. However, it entails lots of challenges as it uses power electronics devices as the power grid interface, which causes a reduction in the system inertia and at the same time affecting the frequency, thereby affecting the stability. To enhance this stability, appropriate control measures need to be adopted. This paper brings forward a novel approach for frequency control support of a wind turbine generator (WTG) in a diesel generation mix. The novelty of this research paper explained on the concurrent application of a Proportional derivative (PD) and a Proportional Integral Derivative (PID) for speed and frequency control in a WTG. The analysis of this experimental research was carried out through the modelling of the rate of change of frequency (RoCoF) using MATLAB / Simulink software. The results showed that the use of these controllers in presence of WTG provide frequency support to the system as the frequency varied within the acceptable limit of ±0.5Hz. Additionally, this experimental research work also proved that the use of speed / governor control in form of the PID improved the RoCoF and provided an enhancement in the stability of the test system. Finally, this paper confirmed that the integration of WTG to the grid required the use of appropriate control algorithm for an efficient exploitation of this kind of renewable energy source.