Single Stage PV Array Fed Speed Sensorless Vector Control of Induction Motor Drive for Water Pumping

ABSTRACT:  

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. The speed is estimated through estimated stator flux. The proposed system includes solar photovoltaic (PV) array, a three-phase voltage source inverter (VSI) and a motor-pump assembly.

An incremental conductance (InC) based MPPT (Maximum Power Point Tracking) algorithm is used to harness maximum power from a PV 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 on an experimental prototype developed in the laboratory.

KEYWORDS:
  1. Speed Sensorless Control
  2. Stator Field-Oriented Vector Control
  3. Photovoltaic (PV)
  4. InC MPPT Algorithm
  5. Induction Motor Drive (IMD)
  6. Water Pump

 SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. PV fed induction motor drive configuration

 EXPECTED SIMULATION RESULTS:

Fig. 2. Starting and MPPT of PV array at 1000 W/m2

Fig. 3. Intermediate signals during starting at 1000 W/m2

(a)

(b)

Fig. 4. Simulation results during starting at 1000 W/m2 (a) Proposed drive (b) Waveforms showing sensed speed and estimated speed

Fig. 5. SPV array performance during decrease in insolation from 1000 W/m2 to 500 W/m2

(a)

 (b)

Fig. 6. Dynamic performance during irradiance decrement from 1000 W/m2 to 500 W/m2 (a) Proposed drive (b) Waveforms showing sensed speed and estimated speed

Fig. 7. PV array performance on increasing insolation from 500 W/m2 to 1000 W/m2

(a)

(b)

Fig. 8. Dynamic performance during irradiance decrement from 500 W/m2 to 1000 W/m2 (a) Proposed drive (b) Waveforms showing sensed speed and estimated speed

CONCLUSION:

 A single stage solar PV array fed speed sensorless vector-controlled induction motor drive has been operated subjected to different conditions and the steady state and dynamic behaviors have been found quite satisfactory and suitable for water pumping. The torque and stator flux, have been controlled independently. The motor is started smoothly. The reference speed is generated by DC link voltage controller controlling the voltage at DC link along with the speed estimated by the feed-forward term incorporating the pump affinity law. The power of PV array is maintained at maximum power point at the time of change in irradiance. This is achieved by using incremental-conductance based MPPT algorithm.

The speed PI controller has been used to control the q-axis current of the motor. Smooth operation of IMD is achieved with desired torque profile for wide range of speed control. Simulation results have displayed that the controller behavior is found satisfactory under steady state and dynamic conditions of insolation change. The suitability of the drive is also verified by experimental results under various conditions and has been found quite apt for water pumping.

REFERENCES:

[1] R. Foster, M. Ghassemi and M. Cota, Solar energy: Renewable energy and the environment, CRC Press, Taylor and francis Group, Inc. 2010.

[2] M. Kolhe, J. C. Joshi and D. P. Kothari, “Performance analysis of a directly coupled photovoltaic water-pumping system”, IEEE Trans. on Energy Convers., vol. 19, no. 3, pp. 613-618, Sept. 2004.

[3] J. 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. 1, pp. 631-641, Jan.-Feb. 2014.

[4] R. 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.

[5] 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.

Induction Motor Drive For PV Water PumpingWith Reduced Sensors

ABSTRACT:

 This study presents the reduced sensors based standalone solar photovoltaic (PV) energised water pumping. The system is configured to reduce both cost and complexity with simultaneous assurance of optimum power utilisation of PV array. The proposed system consists of an induction motor-operated water pump, controlled by modified direct torque control. The PV array is connected to the DC link through a DC–DC boost converter to provide maximum power point tracking (MPPT) control and DC-link voltage is maintained by a three-phase voltage-source inverter. The estimation of motor speed eliminates the use of tacho generator/encoder and makes the system cheaper and robust. Moreover, an attempt is made to reduce the number of current sensors and voltage sensors in the system. The proposed system constitutes only one current sensor and only one voltage sensor used for MPPT as well as for the phase voltage estimation and for the phase currents’ reconstruction. Parameters adaptation makes the system stable and insensitive toward parameters variation. Both simulation and experimental results on the developed prototype in the laboratory validate the suitability of proposed system.

 SOFTWARE: MATLAB/SIMULINK

 CIRCUIT DIAGRAM:

Fig. 1 circuit diagram (a) Proposed system,

EXPECTED SIMULATION RESULTS:

Fig. 2 Performance indices (a) PV array during starting to steady state at 1000 W/m2, (b) IMD indices at 1000 W/m2

 Fig. 3 Performance indices during insolation change 1000–500 W/m2

(a) PV array, (b) IMD indices 500–1000 W/m2, (c) PV array (d) IMD indices

Fig. 4 Adaptation mechanism

(a) Rs adaptation at rated speed and insolation, (b) τr Adaptation at rated speed and rated insolation

Fig. 5 Performance indices of the drive

(a) Starting at 1000 W/m2, (b) Starting at 500 W/m2, (c) Steady state at 1000 W/m2,

(d) Steady state at 500 W/m2

Fig. 6 Dynamic performance of the drive under variable insolation

(a) 1000–500 W/m2, (b) 500–1000 W/m2, (c) Intermediate speed signals at 1000–500

W/m2, (d) Intermediate speed signals at 500–1000 W/m2

Fig. 7 Intermediate signals in terms of

(a) Te* and Te at 1000–500 W/m2, (b) 500–1000 W/m2, (c) Reference stationary

components of flux and estimated flux at 1000–500 W/m2, (d) 500–1000 W/m2

Fig. 8 Reconstructed and measured current waveforms of phases a and b

at (a) Starting performance at 1000 W/m2, (b) 1000 W/m2, (c) 500 W/m2, (d) Boost

converter parameters at 1000 W/m2

CONCLUSION:

The modelling and simulation of the proposed system has been carried out in MATLAB/Simulink and its suitability is validated experimentally on a developed prototype in the laboratory. The system comprises of one voltage sensor and one current sensor, which are sufficient for the proper operation of the proposed system. The motor-drive system performs satisfactorily during starting at various insolations, steady-state, dynamic conditions represented by changing insolation. The speed estimation has been carried out by flux components in stationary frame of reference. The flux and torque are controlled separately. Therefore, successful observation of the proposed system with satisfactory performance has been achieved without the mechanical sensors. This topology improves the stability of the system. The stability of the system at rated condition toward stator resistance variation is shown by Nyquist stability curve and the stability toward the rotor-time constant perturbation is shown by Popov’s criteria. The DTC of an induction motor with fixed frequency switching technique reduces the torque ripple. The line voltages are estimated from this DC-link voltage. Moreover, the reconstruction of three-phase stator currents has been successfully carried out from DC-link current. Simulation results are well validated by test results. Owing to the virtues of simple structure, control, cost-effectiveness, fairly good efficiency and compactness, it is inferred that the suitability of the system can be judged by deploying it in the field.

REFERENCES:

[1] Masters, G.M.: ‘Renewable and efficient electric power systems’ (IEEE Press,Wiley and Sons, Inc., Hoboken, New Jersey, 2013), pp. 445–452

[2] Foster, R., Ghassemi, M., Cota, M.: ‘Solar energy: renewable energy and the environment’ (CRC Press, Taylor and Francis Group, Inc., Boca Raton, Florida, 2010)

[3] Parvathy, S., Vivek, A.: ‘A photovoltaic water pumping system with high efficiency and high lifetime’. Int. Conf. Advancements in Power and Energy (TAP Energy), Kollam, India, 24–26 June 2015, pp. 489–493

[4] Shafiullah, G.M., Amanullah, M.T., Shawkat Ali, A.B.M., et al.: ‘Smart grids: opportunities, developments and trends’ (Springer, London, UK, 2013)

[5] Sontake, V.C., Kalamkar, V.R.: ‘Solar photovoltaic water pumping system – a comprehensive review’, Renew. Sustain. Energy Rev., 2016, 59, pp. 1038– 1067

Single Stage SPV Array Fed Speed Sensorless Vector Control of Induction Motor Drive for Water Pumping

ABSTRACT:

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.

 

KEYWORDS:

  1. Speed Sensor-less Control
  2. Stator Field oriented Vector Control
  3. Solar Photovoltaic (PV)
  4. I&C MPPT Algorithm
  5. Induction Motor Drive (IMD)
  6. Water Pump

 

SOFTWARE: MATLAB/SIMULINK

 

BLOCK DIAGRAM:

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’

 

CONCLUSION:

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.

 

REFERENCES:

  • 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.