A FEASIBILITY STUDY OF SOLAR PHOTOVOLTAIC POWER SMOOTHING USING FUZZY LOGIC APPROACH

Abstract

Penetration of Variable Renewable Energy (VRE) is a challenge for safe grid integration. The short-term variation of solar irradiance, which is initiated by moving clouds, causes fluctuations in Solar Photovoltaic (SPV) power generation and can jeopardize grid stability. The fluctuations in the output power of the SPV plants are the reason for the dynamic change of load flow in the interconnection area of the utility network. To assess the short-term variation of solar irradiance, 1-year time-series solar irradiance data have been collected from a Solar Irradiance Measurement Station; located at Chittagong University of Engineering and Technology (CUET), Chittagong, Bangladesh. The collected data from the case study site reveals that the short-term variation of solar irradiance is significant especially from April to September. Furthermore, a feasibility study of SPV power smoothing has been conducted using the Fuzzy Logic approach to identify the requirement of the Energy Storage System (ESS) as well as to minimize the solar ramp rate and ramp level. An 8 MWh ESS with an 8 MW power capacity has been identified as the capacity of the ESS support system for smoothing a 20 MWp solar plant. The daily support amount and the surplus amount have been calculated for solar power smoothing and that found identical in terms of energy and power. Although this feasibility study gives a directive on grid integration aspects before establishing a large utility-scale SPV plant, the actual scenarios may be slightly different due to the geographical dispersion, cloud enhancement and similar other effects.

Keywords

• solar irradiance
• variable renewable energy
• short-term variation
• solar power smoothing
• fuzzy logic
• feasibility study
• energy storage.