Frequency And Voltage Control In Distribution System With Higher Penetration Of PV/Battery System In Eritrea

The use of grid connected PV is growing, however, PV generation is intermittent. It can cause mismatch between the generated power and the power consumed which can lead to undesirable effect. This thesis aims to control output power of grid connected PV/battery system with focus on frequency and voltage control support in an isolated LV distribution system containing residential consumers.Based on basic theory of photovoltaic and standard data sheet, PV module has been implemented in Simulink and PV module characteristics have been studied. The PV/battery system is formed by connecting PV array to a common DC bus through boost DC-DC converter and the battery is connected to the DC bus through bidirectional DC-DC converter. DC-AC converter is used to connect the PV/battery system to the grid. The DC-DC converter is operated to track the maximum available PV power. The bidirectional converter manages the power flowing in to or out of the battery and also regulates DC-bus voltage. The DC-AC converter outputs ac voltage in synchronous with the grid voltage and allows decoupled control of active and reactive power injected to the grid. The validity of the models and control scheme is verified by simulation results.The dwelling demand of residential consumers is highly variable. The combined variability of PV generation and load demand in a network containing grid connected PV can lead to undesirable effect in the network. To prevent any undesirable effects in an electric network, the reference active and reactive powers should respond to the change in PV generation and local load demand. To achieve this goal, an algorithm is developed to calculate the reference active and reactive power using irradiance data and dwelling demand data of high time resolution. This reference values are used by the power controller to drive the inverter. The method is tested in a residential neighborhood containing720houses where some houses contain PV/battery system.