Photovoltaic Thermal Power Supply Based on Smart Grid Functioning Solar Electric System Network

Abstract

Integrated Smart Grid systems are developed to coordinate the production and consumption of electricity from a grid-connected solar power plant, providing power to a heat pump and hot water using hybrid solar collectors. The upper section of a two-section storage tank supplies hot water, while the lower section is a low-grade energy source for the heat pump. The integrated dynamic subsystem of the solar power system includes the following components: the grid, photovoltaic solar panels, hybrid solar collectors, a grid-connected inverter, a heat pump, a two-section storage tank, and a frequency converter. The power factor and local water temperature of the grid-connected solar power system are predicted by measuring the voltage of the hybrid solar collectors at the grid-connected inverter input, the voltage at the frequency converter output, and the current frequency. Advanced solutions for varying the power of the heat pump compressor motor and the circulation pump motor are implemented in accordance with changes in the thermal output of the storage tanks connected to the hybrid solar collectors. The power of the heat pump compressor motor and the circulating pump motor is regulated based on the specified voltage ratio at the grid-tie inverter input from the hybrid solar collectors and at the frequency converter output. The functional assessment of the solar power system power factor change when connecting the heat pump is in the range of 58–98%, when connecting the hot water supply, in the range of 63.74–98%, and the local water temperature in the range of 35–55°C. When the grid-tie inverter input voltage changes from 200 V to 600 V, the power transmitted to the grid increases in the range of 0.33 to 1, the power factor by 40%. Determining the final functional information allows for early decisions to be made about changing the operating mode of the heat pump compressor motor and the circulating motor to prevent peak loads on the power grid and maintain voltage in the distributed system.