Development of utility assisting controllers for solarised irrigation system

Abstract

Several initiatives were taken by the Government of India (GoI) to increase the solar energy generation and had set a target of installing 100 GW grid-connected, solar power projects by 2020. Due to the unreliability of the solarised system and limitations of energy storage systems, grid-connected PhotoVoltaic (PV) has its own advantage over the stand alone systems. Analysis of distribution voltage profile indicates its dependence on the loading of the house and can be slightly different for different utility companies. An attempt is made to develop the irrigation pump controller which will perform the switching while considering the PV generation availability, utility voltage conditions, water availability and other field conditions for irrigating paddy crop in clay loam soil. The low cost, microcontroller-less switching module being developed can perform the pump switching according to PV and water availability, utility voltage and soil moisture condition. In contrast, the microcontroller based system is more flexible and can operate the pump switching according to several sensing quantities like PV generation, trend of the utility voltage over a finite time, crop ripening input, water availability in the reservoir, soil moisture level and temperature and humidity condition in the field. This will ensure the automatic protection of the pump against under-voltage, overvoltage, frequent voltage fluctuations and dry running while assisting the utility grid throughout the day and thereby providing the basic requirements of demand response. Although the microcontroller-less switching system will be simpler and cheaper, the microcontroller based system will have greater versatility and reliability.