A Review of Interconnection Rules for Large-Scale Renewable Power Generation

Abstract

Around the world penetration levels of renewable-based power into power systems have been increasing rapidly over the last few years. In the year 2011, almost half of the estimated 208 GW of newly added electric capacity was reported from renewable-based generation. Wind and solar photovoltaic (PV) generators accounted for almost 40 % and 30 % of new renewable capacity, respectively, followed by hydropower. Besides rooftop and small-scale systems, the trend toward very large-scale wind farms and ground-mounted PV systems continued to play an important role. It is evident that renewable-based generation will be comparable to conventional power generation in the coming decades. Therefore, many transmission system operators (TSOs) and regulators around the world have come up with interconnection rules/codes to request these volatile renewable resource-based power plants to have more or less the same operating competence as conventional power plants. Depending on system characteristics and renewable penetration levels, the level of requirements imposed by these grid codes are getting more stringent over time to ensure the common aim of secured and reliable power system operation. This chapter presents a comprehensive study of the grid interconnection rules set by various TSOs and regulators for large renewable-based power plants. A brief discussion explaining the necessity of grid codes has been presented in the beginning, followed by a list of principal static and dynamic operation issues usually addressed in existing grid codes. A comparative study has then been carried out to compare various rules among grid codes around the globe. The study focuses on the primary concerns such as active and reactive power regulations under static operation, active and reactive power response during and after faults, and fault ride-through requirements imposed by the codes. A useful discussion on future trends for synchronizing diverse grid codes has also been presented. The contents of this chapter will be helpful for regulators as well as for renewable-based generator manufacturers to form better frameworks, which will ultimately result in secure system operation with increased penetration of large-scale renewable generation.