An investigation on the power system stability of photovoltaic grid integrated system

Renewable energy (RE) is one of the leading industry blooming around the globe. The usage of renewable energy benefits the entire nation in all ways such the social, culture and environment. Besides that, the hike in the fossil fuel price in the market increase the demand in industry for the search of renewable energy as a conventional method to generate electricity. However, installation of solar photovoltaic (PV) for electricity generation might be not a good mitigation for the problem whereby some internal issues to be rectified and to be stabilized for the better power quality to be generated. Therefore, this paper study on voltage stability analysis on power grid with integrated solar PV system. The stability of voltage has to be taken care to avoid major problem occurrence such as voltage sag. Besides, the installation of PV can produce different PV penetrating rate which indirectly affects the voltage stability. This studies on the voltage stability problems integration of photovoltaic to IEEE-14 bus networks. In this research project NVSI used to find the weak bus for injection of three phase fault for fault analysis. The faulted bus was mitigated by using the photovoltaic system.

I. Introduction

Renewable energy is one of the leading industry blooming around the globe. In the gap of one decade, about 49% increase is noticed in the usage of renewable energy throughout the world [1]–[2]. According to the power utility company, Tenaga Nasional Berhad (TNB) of 2017, solar energy is considered one of the most promising renewable resources in Malaysia, and grid connected solar farms will be increasingly developed in the next 15 years. Recently, TNB has invested RM 350Millions for the first large scale solar (LSS) with capacity of 50MW to boost the generation capacity from 23.3 MW to 73.3 MW in 2018. Thus, it is crucial to investigate voltage stability within the grid when it is associated with PV generation. As far as voltage is concerned, it is one of the important parameters in a system which plays a major role in power plant and the voltage stability has to be taken care to avoid major problem occurrences. Due to the probabilistic in nature of PV generation and significant difference from conventional synchronous generators, a significant increase in solar generations in the grid may present technical challenges and major impacts on system stability. Various studies have been conducted to simulate and investigate the effects of solar power on power system stability [3]–[4]. In PV penetrating rate is one of the causes which can influence the voltage stability. The PV penetration will improve the stability performance of a power system [3]. PV will increase the real power and improves the reactive power of a particular power system [4]–[5]. Grid connected solar photovoltaic system is where the power system is being energized by the photovoltaic panels installed in particular buildings and the power source is supplied via utility grid. This paper study on the voltage stability problems after three phase fault was injected to the systems that incorporated solar power generations. The proposed algorithm is applied to IEEE-14 bus to assess voltage stability and compute voltage under fault condition. The numerical results show that the impact of PV integration on system voltage stability.