Operation and Control of Off-Grid Systems

This chapter is concerned with the operation and control of off-grid systems in rural communities in developing countries. An important consideration is the charging and discharging of the battery bank. This chapter describes the three-stage battery charging process, consisting of bulk, absorption, and float stages. Battery discharge control based on low-voltage disconnection is detailed. Methods and models for analyzing the current and power flow in off-grid systems with multiple sources, charge controllers, diversion load controllers, and loads are presented. The frequency and voltage control of synchronized generator sets is presented. The chapter concludes by describing the algorithms used in maximum power point trackers for solar photovoltaic systems.