Reduced Sensor Based PV Array Fed Direct Torque Control Induction Motor Drive for Water Pumping

 ABSTRACT:

This paper aims at the design, control and implementation of a solar photovoltaic (PV) array fed speed sensorless direct torque control (DTC) of an induction motor drive (IMD) for water pumping in standalone as well as battery connected hybrid mode. This stator flux estimated by proposed flux observer, is used for speed estimation. A DC link current sensor is used to reconstruct the motor phase currents by modified active voltage vector. One voltage sensor for DC link voltage sensing and only one current sensor for DC link current sensing, are used in this system for standalone operation of the system. All other required quantities are estimated through these two sensed signals. The IMD is energized by a photovoltaic (PV) array, which is operated at maximum power point (MPP). A perturb and observe control algorithm with additional flow rate controller, is proposed for MPP, which tracks MPP throughout the operating range and provides the facility to control flow rate. The suitability of the system is judged through simulated results in MATLAB/Simulink as well as test results obtained on a prototype developed in the laboratory.

KEYWORDS:

1.      PV Array

2.      Single Stage System

3.      Perturb and Observe (P&O) Algorithm

4.      Direct Torque Control (DTC)

5.      Speed Sensorless

6.      Current Reconstruction

7.      Induction Motor

8.      Submersible Water Pump

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1 Scheme of proposed PV-battery system

EXPECTED SIMULATION RESULTS:

Fig. 2 Bode plot showing the frequency response of flux observer with the

conventional technique

                                                 (a)                                                                                         (b)

Fig. 3 Performance indices: (a) PV array during starting to steady-state at

1000W/m2 (b) IMD indices at 1000W/m2

(a)

(b)

                                             (c)                                                                                               (d)   

                                                                                     

  (e) 

     

                                                                                                        

(f)

Fig. 4 Performance indices during insolation change (a) PV array:1000W/m2-

500W/m2 (b) Induction motor drive:1000W/m2-500W/m2 (c) PV array:

500W/m2-1000W/m2 (d) Induction motor drive: 500W/m2-1000W/m2

(e) PV array:100W/m2-1000W/m2 (f) Induction motor drive:

100W/m2-1000W/m2

                                                               (a)                                                                          (b)

(c)

(d)

Fig. 5 Simulation results at rated insolation and (a) Rated flow rate (b) 80%

of rated flow rate (c) 60% of rated flow rate (d) 40% of rated flow rate

Fig. 6 Stator flux trajectory at rated condition of proposed system

                                                 (a)                                                                                (b)

                                                                                           (c)

Fig. 7 Performance parameters of hybrid system (a) PV parameters (S, Vdc,

Vpv, Ipv) (b) Battery indices (Vdc, SOC, Vbat, Ibat) (c) Motor indices

(a)

(b)

(c)

Fig. 8 Performance parameters during battery charging of hybrid system (a)

PV parameters (S, Vdc, Vpv, Ipv) (b) Battery indices (Vdc, SOC, Vbat, Ibat)

(c) Motor indices

Fig. 9 Starting performance of the drive: (a) 1000W/m2 (b) 500W/m2

CONCLUSION:

The proposed solar PV array fed water pumping system has been modeled and simulated in MATLAB/Simulink in standalone and PV array-battery connected modes, and its suitability is studied experimentally on a prototype in the laboratory. In standalone mode with PV array feeding water pump, the system comprises of one voltage sensor and one current sensor, which are sufficient for the proper operation of proposed system. Moreover, a P&O based MPPT with derating feature technique has been proposed to regulate the flow rate by controlling the PV array power, thereby enabling the user to operate the pump for any discharge and flow rate. The motordrive system performs satisfactorily during starting at various insolations, steady-state, dynamic conditions represented by changing insolation. The speed is estimated in stationary flux components by flux observer, which has been used for DC offset rejection as well as for the satisfactory operation at lower frequency. The flux and torque, are controlled separately. The direct torque control (DTC) is achieved with fixed frequency switching technique for reducing 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. In addition, a smooth changeover facility from DTC to scalar control has been provided to ensure the uninterrupted performance of the system even though the current sensor fails. The switching signals are generated by space vector modulation technique (SVM) to drive three phase VSI, which has offered less harmonics distortion (THD) in motor currents as compared with SPWM technique. Simulation results are well validated by experimental results. In the second mode, a successful implementation of bidirectional power flow between PV arraybattery connected systems has been achieved and its suitability has been checked at various conditions. Owing to the virtues of simple structure, control, cost-effectiveness, fairly good efficiency and compactness, it can be inferred that the suitability of the system can be judged by deploying it in the field.

REFERENCES:

[1] G. M. Masters, Renewable and efficient electric power systems, IEEE Press, Wiley and Sons, Inc. 2013, pp. 445-452.

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

[3] S. Parvathy and A. Vivek, “A photovoltaic water pumping system with high efficiency and high lifetime,” Int. Conf. Advancements in Power and Energy (TAP Energy), pp.489-493, 24-26 June 2015.

[4] G. M. Shafiullah, M. T. Amanullah, A. B. M. Shawkat Ali, P. Wolfs, and M. T. Arif, Smart Grids: Opportunities, Developments and Trends. London, U.K.: Springer, 2013.

[5] Vimal Chand Sontake and Vilas R. Kalamkar, “Solar photovoltaic water pumping system - A comprehensive review,” Renewable and Sustainable Energy Reviews, vol. 59, pp. 1038-1067, June 2016.

Solar PV Array Fed Direct Torque Controlled Induction Motor Drive for Water Pumping

 ABSTRACT:

This paper deals with the solar photovoltaic (PV) array fed direct torque controlled (DTC) induction motor drive for water pumping system. To extract maximum power from the solar PV array, a DC-DC boost converter is employed. The soft starting of a three-phase induction motor is achieved by controlling the DC-DC boost converter through the incremental conductance maximum power point tracking (MPPT) technique. The induction motor is well matched to drive a type water pump due to its load characteristics. It is well suited to the MPPT of the solar PV array. By using DTC technique, an induction motor exhibits homogeneous or even better response than the DC motor drive. The proposed system is designed and its performance is simulated in MATLAB/Simulink platform. Simulated results are demonstrated to validate the design and control of the proposed system.

KEYWORDS:

1.      Solar Photovoltaic (PV)

2.      Direct Torque Control (DTC)

3.      MPPT Control

4.      Induction Motor

5.      Water Pump

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

Fig.l Schematic diagram of proposed system configuration

 EXPECTED SIMULATION RESULTS:

Fig.2 Steady state performance of proposed system

Fig.3 Starting performance of proposed system

Fig.4 Performance of the system at decrease in insolations

Fig.5 Performance of the system at increase in insolations

CONCLUSION:

It has been demonstrated that the solar PV array fed DTC controlled induction motor drive has been found quite suitable for water pumping. A new method for reference speed generation for DTC scheme has been proposed by controlling the voltage at DC bus and pump affinity law has been used to control the speed of an induction motor. Solar PV array has been operated at maximum power during varying atmospheric conditions. This is achieved by using incremental conductance based MPPT algorithm. The speed PI controller has controlled the motor stator current and controlled the flow rate of pump. Simulation results have demonstrated that the performance of the controller has been found satisfactory under steady state as well as dynamic conditions.

REFERENCES:

[I] R. Foster, M. Ghassemi and M. Cota, Solar energy: Renewable energy and the environment, CRC Press, Taylor and francis Group, Inc. 20 I O.

[2] S. Jain, Thopukara, AK. Karampur and V.T. Somasekhar, "A SingleStage Photovoltaic System for a Dual-Inverter-Fed Open-End Winding Induction Motor Drive for Pumping Applications," iEEE Trans. On Power Electro.. vo1.30, no.9, pp.4809-4818, Sept. 2015.

[3] M. A Razzak, A S. K. Chowdhury and K. M. A Salam, "Induction motor drive system using Push-Pull converter and three-phase SPWM inverter fed from solar photovoltaic panel," international Conference on 2014 Power and Energy Systems: Towards Sustainable Energy, 13- 15 March 2014.

[4] J.V. Caracas Mapurunga, G. Farias Carvalho De, L. F. Moreira Teixeira, L.A Ribeiro De Souza, "Implementation of a HighEfficiency, High-Lifetime, and Low-Cost Converter for an Autonomous Photovoltaic Water Pumping System," iEEE Trans. On ind. Appl., vo1.50, no.!, pp.631-641, Jan.-Feb. 2014.

Sizing and Simulation of an Energy Sufficient Stand-alone PV Pumping System

ABSTRACT:

In this paper, methods for sizing of PV pumping systems and the simulation of (DTC) Direct Torque Control of induction motor that is used for piloting a water pump supplied by a photovoltaic generator are presented. The sizing of the PV pumping system is based on the calculation of the water needs, the required hydraulic energy and the estimation of available solar power. The best sizing of the PV pumping system may further help in reducing its cost and optimize its efficiency. The proposed system includes a solar panel, a DC/DC converter with MPPT control, a voltage inverter with pulse width modulation (PWM). The Pump is driven by a Three Phase Induction Motor. In order to control the water flow in the pump, Direct torque control of induction machine is used. The simulations are carried out in Matlab/Simulink.

KEYWORDS:

1.      MPPT

2.      DTC

3.      PV pumping

4.      Photovoltaic

5.      Three phase induction motor

6.      Induction machine (IM)

7.      Voltage inverter

8.      Pulse width modulation (PWM)

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. System block diagram

 EXPECTED SIMULATION RESULTS:

Fig. 2. Band hysteresis of flux

Fig. 3. Statoric Flux evolution

Fig. 4. Electromagnetic Torque

Fig. 5. Stator current dq Axis

Fig. 6. The motor speed

CONCLUSION:

In this paper, a case study of stand-alone PV pumping system designed for irrigation needs in a remote site in Tunisia. The sizing method for the structure was presented. MPPT technique was used to optimize the power delivered by the photovoltaic module. Direct torque control technique served to control the induction machine speed and therefore the flow of the centrifugal pump. The paper presented the system block diagram, the MPPT control algorithm, the DTC block diagram and design. The main objective of this work is to maximize savings in energy consumption by ensuring that pipelines and networks are sized and designed accurately. The use of DTC technique ensures better efficiency of the motor. The experimental results are satisfactory and suggest that the proposed solution can be a reliable option to overcome the lack of electricity at remote locations and rural areas. More reliability test and studies needs to be performed to guarantee its robustness, efficiency and cost effectiveness.

REFERENCES:

[1] “Solar resource maps for Tunisia”, Solargis S.R.O Slovakia, Maps.

[2] Chaabane. M, Ben Djemaa. A. and Kossentini, “A daily and hourly global irradiations in Tunisia extracted from Meteosat Wedax images”, Solar Energy, vol. 57, issue 6, pp. 449-457.

[3] Information obtained from the direction of the bureau of organic farming, CRDA Tozeur.

[4] T. Augustyn. “Energy efficiency and savings in pumping systems, The holistic approach”, Energy Efficiency Convention (SAEEC), 2012 Southern African.

[5] Jim McGovern, “Technical Note: Friction Factor Diagrams for Pipe Flow”, Dublin Institute of Technology, 2011.

PV-Battery Powered Direct Torque ControlledSwitched Reluctance Motor Drive

ABSTRACT:

Categorized as one of the renewable energies, Photo- Voltaic system has a great potential compared to its counterparts of renewable energies. This paper deals with the design of a Photovoltaic (PV)-Battery fed Switched Reluctance Motor(SRM). The system mainly composed of a PV module, boost converter, rechargeable battery, bidirectional converter, asymmetric bridge converter, SRM and system controllers. The main problems of SRM are high torque ripple, acoustic noise and vibration problems. In order to reduce these problems, a new direct torque control of 3.5 kW 8/6 SRM is proposed, which is simple and can be implemented with low cost processor. It can be seen from the simulation results that this scheme has well regulated the torque output of the motor with in hysteresis band. The proposed system assures its suitability for solar applications like solar vehicles, solar water pumping system and floor mills in hilly and isolated areas.

KEYWORDS:

1.      PV module

2.      Switched reluctance motor

3.      Direct torque control

4.      Battery energy storage system

SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Figure 1. (a)PV-Battery fed Induction Motor drive (b) PV-Battery Switched Reluctance Motor drive

 EXPECTED SIMULATION RESULTS:

Figure 2. Variation of PV output voltage and current due variation in solar

Radiation

Figure 3. Control of flux vector with in hysteresis band

Figure 4. Flux trajectory in d-q plane

Figure 5. Current waveform of different phases

Figure 6. Control of torque in hysteresis band

Figure 7. Flux waveform of different phases

CONCLUSION:

The proposed scheme reduces dc link voltage there by reducing capacitor size and insulation level. A single stage conversion is also possible without the use of boost converter. The advantage of using asymmetric bridge converter is freedom to control individual phase independently and no shoot through fault. Torque ripple in the SRM can be eliminated by Direct Torque Control technique. The results indicate that DTC of SRM can directly regulate the torque output of the motor within a hysteresis band.

 REFERENCES:

[1] Jewell W.T and Ramkumar R “The history of utility –interactive photovoltaic generation”,IEEE/PES procedings ,Vol 30 pp1-5,Feb 1988.

[2] J. Applebaum J and Sarma M.S;“The operation of permanent magnet dc motors powered by a common source of solar cells,.” IEEE Trans. On EC., ,Vol. 4, pp.635-641, dec 1989 .

[3] Putta Swamy C L, Singh Bhim and Singh B P; “Dynamic performance of permanent magnet brushless DC powered by a PV array for water pumping,. ”Journel of Solar materials and Solar cells, ,Vol. 36, No.2 pp.187-200,1995

[4] Bhat S.R, Pittet A and Sonade B S; “Performance optimization ofinduction motor pump system using photovoltaic source,.”IEEE Transon Industrial Applications., ,Vol. 23, No 6 pp.955-1000, Nov/Dec 1987.

[5] Daud, and M. Mahmoud; “Solar Power Induction Motor Drive WaterPump Operating on a Desert Well, Simulation and Field Test”,,.” IEEE Trans.on Renewable Energy, ,Vol. 30, pp.701-714,2005.