Grid and solar pv based water pumping using induction motor
Introduction:
Welcome to LMS Solution! In this blog post, we will explore the integration of a grid system with a solar PV-based water pumping system utilizing an induction motor. This hybrid system efficiently harnesses power from both the grid and solar PV to drive the water pump, ensuring reliable and sustainable operation.
Grid System:
The grid system comprises a single-phase grid with an amplitude of 230 volts RMS. A diode rectifier converts AC to DC, followed by an LC filter to smooth the DC output. To improve power factor and make the source current sinusoidal, a power factor correction converter is employed. This converter is controlled using a proportional-integral (PI) controller based on the phase-locked loop (PLL) approach.
The DC link voltage is compared with a reference voltage, and the error signal is processed by a PI controller to generate a reference current. This reference current, when multiplied by a sinusoidal waveform, rectifies the output, ensuring the source current is sinusoidal. The system is controlled by comparing this reference current with the actual source current.
Solar PV System: The solar panel has a rating of 210 watts, operating at 28.7 volts and 1.32 amps at the maximum power point. A boost converter, controlled by an incremental conductance Maximum Power Point Tracking (MPPT) algorithm, optimizes power extraction from the solar panel. The boosted output is then connected to the grid system.
Induction Motor Drive:
The induction motor, acting as a water pump, is a three-phase motor with its speed controlled by a field-oriented control (FOC) scheme. The FOC ensures the motor operates efficiently at a constant speed. The system has three modes of operation:
Mode 1: Solar PV supplies power, and the grid is off.
Mode 2: The grid supplies power to the motor, and solar PV is off.
Mode 3: Both solar PV and the grid supply power to the motor.
Simulation Results:
Mode 1 Operation: Solar PV powers the motor. Source current, PV power, and DC link voltage exhibit expected behaviors.
Mode 2 Operation: The grid powers the motor. Power factor improves, and the induction motor operates at a constant speed.
Mode 3 Operation: Both solar PV and the grid supply power. The system adapts to changes in irradiation levels.
Conclusion:
The grid interface to a solar PV-based water pumping system utilizing an induction motor demonstrates versatile operation in different modes. This hybrid approach ensures continuous water pumping by intelligently utilizing power from both solar and the grid, making it an efficient and sustainable solution.