This paper deals with a single stage solar powered speed sensorless vector controlled induction motor drive for water pumping system which is superior to conventional motor drive in terms of reliability and cost. The speed is estimated through estimated stator flux. The proposed system includes solar PV (photovoltaic) array, a three-phase voltage source inverter (V SI) and a motor-pump assembly. An incremental and conductance (I&C) MPPT (maximum power point tracking) algorithm is used to harness maximum power from SPV array. The smooth starting of the motor is attained by vector control of an induction motor. The desired configuration is designed and simulated in MATLAB/ Simulink platform and the design, modeling and control of the system are validated through demonstration of simulation results.
- Speed Sensor-less Control
- Stator Field oriented Vector Control
- Solar Photovoltaic (PV)
- I&C MPPT Algorithm
- Induction Motor Drive (IMD)
- Water Pump
Fig. 1. Schemetic Diagram of Single Stage Solar Powered Induction Motor Drive
EXPECTED SIMULATION RESULTS:
Fig. 2 Starting and MPPT of Solar PV Fed System at IOOOW/m’
Fig. 3. Speed Estimation during Starting and MPPT of Solar PV Fed System at IOOOW/m’
Fig. 4. Smooth Starting of lnduction Motor Fed Water Pumping System at IOOOW/m’
Fig. 5: Performance of the Solar PV Panel during Decrease in Insolation from IOOOW/m’to 500W/m’
Fig. 6: Induction Motor Performance during Decrease in Insolation from IOOOW/m’ to 500W/m’
Fig. 7: Performance of the Solar PV Panel during Increase in Insolation from 500W/m’ to IOOOW/m’
Fig. 8: Induction Motor Performance of the System during Increase in Insolation from 500W/m’ to 1000W/m’
A single stage solar PV array fed speed sensor-Iess vector-controlled induction motor drive has been operated under various conditions and the steady-state and dynamic behavior has been found quite suitable for water pumping. The torque and stator tlux have been controlled independently. The motor is started smoothly. The reference speed is generated by stator flux oriented vector control scheme which has been proposed by controlling the voltage at DC bus and pwnp affinity law is used to regulate the speed of an induction motor. The SPV array has maintained peak power point during chan ging irradiance. This is achieved by using incremental and conductance (I&C) based MPPT algorithrn. The speed PI controller has controlled the motor stator currents and controlled the tlow rate of pwnp. Smooth and stable operation of IMD has been achieved with stable torque profile for wide range of speed control. Simulation results have displayed that the controller behavior is found satisfactory under steady state and dynamic condition of insolation change.
- Foster, M. Ghassemi and M. Cota, Solar energy: Renewable energy and the environment, CRC Press, Taylor and francis Group, Inc. 2010.
- Kolhe, J. C. Joshi and D. P. Kothari, “Performance analysis of a direct1y coupled photovoltaic water-pumping system”, IEEE Trans. on Energy Convers., vol. 19, no. 3, pp. 613-618, Sept. 2004.
- V. M. Caracas, G. D. C. Farias, L. F. M. Teixeira and L. A D. S. Ribeiro, “Implementation of a High-Efficiency, High-Lifetime, and Low-Cost Converter for an Autonomous Photovoltaic Water Pumping System”, IEEE Trans. Ind. Appl., vol. 50, no. I, pp. 631- 641, Jan.-Feb. 2014.
- Kumar and B. Singh, ” Buck-boost converter fed BLDC motor for solar PV array based water pumping “, IEEE Int. Conf Power Electron. Drives and Energy Sys. (PEDES), 2014.
- Zhang Songbai, Zheng Xu, Youchun Li and Yixin Ni, “Optimization of MPPT step size in stand-alone solar pumping systems”, IEEE Power Eng. Society Gen. Meeting, June 2006.