Novel Back EMF Zero Difference Point Detection Based Sensorless Technique for BLDC Motor

ABSTRACT:

In this paper a novel position sensorless scheme named Back EMF Zero Difference Point (ZDP) detection has been proposed for six-switch VSI converter fed permanent magnet BLDC motor. This technique is based on the comparison of back EMFs and detection of the points in the back EMF waveforms where they cross each other or in other words they are equal. Commutation point is achieved exactly at the same instant when the difference of back EMFs of any two phases becomes zero. The simulation study has been carried out for the proposed sensorless scheme. The proposed sensorless scheme has the excellent performance from zero to the extra high speed. The method needs no additional delay circuit as used for calculation of commutation point from back EMF ZCP and involves less calculation burden. The method is fault tolerant and accurate even in the case of noise in measurement (or estimation) of phase back EMFs. A nonzero threshold value proportional to input voltage (or reference speed) is used for overcoming the problem due to quantization and sampling for digital implementation. This method proves to be excellent substitute of hall sensing scheme as it also senses at zero speed.

KEYWORDS:

  1. BLDC motor
  2. Back EMF ZDP
  3. Commutation
  4. Sensorless control
  5. Zero difference point.

 SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig.1 VSI fed BLDC motor with indirect Back EMF detection scheme

EXPECTED SIMULATION RESULTS:

Fig.2. Phase Back EMF ZDPs, switching signals, counter output and triggering sequence signals.

Fig.3. Steady state operation at the low speed of 600 rpm.

Fig.4. performance of proposed sensorless scheme at 17000 rpm

Fig.5. Noise immune performance during steady state operation for reference speed of 17000rpm.

Fig.6. sensing fault occurs at 0.5 second in the measurement of phase-B back EMF.

Fig.7. speed increases when sensing fault occurs (here phase-B sensing fault

CONCLUSION:

In the proposed Back EMF Zero Difference Point (ZDP) detection method, the very first commutation signal is achieved at starting itself i.e. one step before the ZCP method, which proves the superiority of the method. The back EMF for the proposed scheme can be applied to various existing back EMF detection or estimation techniques. This technique is insensitive to the inherent noise in measurement (or estimation) of back EMF. This method does not need extra

Circuitry as needed for delay after ZCP for getting commutation point, thereby less computational complexity is involved. The speed (or input voltage) proportional threshold used for avoiding uncertainty in the zero difference of back EMF, sets its scope of wide usability in precise operation from zero to extra high speed. Operation at initial zero back EMF is the main strength of this method and it doesn’t necessitate separate starting techniques. Speed response at transient period is 0.15 ms faster than previous methods for identical motor parameters.

REFERENCES:

[1] M.V.Kesava Rao, Department of Electrical technology, IISc Bangalore, ‘‘Brush Contact Drops in DC machines’’, Accepted 25-6-1934, Bangalore Press.

[2] Y.S. Jeon, H.S. Mok, G.H. Choe, D.K. Kim, J.S. Ryu, “A New Simulation Model of BLDC Motor with Real Back EMF waveform”, 7 th workshop on Computers in power Electronics , 2000 (COMPEL 2000), page 217- 220.

[3] Padmaja yedmale, “Brushless DC (BLDC) Motor Fundamentals”, AN885, 2003 Microchip Technology.

[4] S. Tara , Syfullah Khan Md “Simulation of sensorless operation of BLDC motor based on the zero cross detection from the line voltage” International Journal of Advanced Research in Electrical Electronics and Instrumentation Engineering, vol 2, issue 12 , December 2013, ISSN 2320-3765.

[5] J. R. Frus and B. C. Kuo, “Closed-loop control of step motors using waveform detection,” in Proc. Int. Conf. Stepping Motors and Systems, Leeds, U.K., 1976, pp. 77–84.

 

A Novel Fuzzy Dynamic Observer for High Speed BLDC Motor

ABSTRACT:

In this paper, a high performance brushless DC (BLDC) motor drive based on a fuzzy dynamic observer (FDO) is investigated. The FDO acts on the motor current and its gains are corrected by estimating current, rotor position and speed by fuzzy logic control (FLC). FLC is correcting gain’s FDO via real time. A PI speed control was chosen due to its low processing time and fast control. In order to reduce the model complexity, the back-EMF is assumed as being trapezoidal in a simplified machine model. The presented drive has been simulated by the MATLAB/SIMULINK software on the high speed BLDC motor model. Simulation results show that the proposed drive is able to estimate the rotor position and speed with high precision when high speeds are considered. Simulation results also show the reliability, fast computation and excellent dynamic performance with using fuzzy logic for high speed BLDC motor.

KEYWORDS: 

  1. BLDC motor
  2. Fuzzy dynamic observer
  3. Fuzzy logic

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Block diagram of speed control of a three-phase BLDC motor.

EXPECTED SIMULATION RESULTS:

Fig. 2. Speed of rotor (N=30,000 rpm).

 Fig. 3. Back EMF three-phases (N=30,000 rpm).

Fig. 4. Total torque (N=30,000 rpm).

Fig. 5. Speed and estimated speed with FDO (N=30,000 rpm).

Fig. 6. Rotor position and estimated position with FDO (N=30,000 rpm).

Fig. 7. Speed estimated error with FDO (N=5,000 rpm, N=10,000 rpm and N=30,000 rpm).

CONCLUSION:

In this study, a fuzzy dynamic observer (FDO) scheme for a high speed BLDC motor drive is investigated. FDO micro gains are regulation by using fuzzy logic control (FLC) via real time. This approach has been simulated on a high speed BLDC motor nonlinear model. The FDO acts on the phase currents and also the micro gains will be quickly regulated real time according to error values by FLC. Also, the use of PI speed control accelerates the calculations of the rotor position estimation and speed. In this study, simulation results show that FDO are suitable for high speed BLDC motors and torque ripple is one of the indirect factors affecting the errors estimation. Nevertheless, these results show that the FDO is suitable for high speeds. In addition, as torque ripple is one of the main estimation error this parameter can be decrease by the torque ripple optimization.

 REFERENCES:

[1] Lei Hao, H. A. Toliat, “BLDC Motor Full-Speed Operating Using hybrid Sliding Mode Observer “Applied Power Electronics Conference and Exposition, APEC ’03. Eighteenth Annual IEEE, vol. 1, pp. 286 – 293, February 2003.

[2] S. M. M. Mirtalaei, J. S. Moghani, K. Malekian, B. Abdi, “A Novel Sensorless Control Strategy for BLDC Motor Drives Using a Fuzzy Logic-based Neural Network Observer “International Symposium on Power Electronics, Electrical Drives, Automation and Motion, SPEEDAM 2008. IEEE, vol. 1, pp. 1491 – 1496, July 2008.

[3] Li Qiang, W. Ruixia, “Study on Rotor Position Detection Error in Sensorless BLDC Motor Drives “5th International Conference Power Electronics and Motion Control, IPEMC 2006. IEEE, vol. 3, pp. 1-5, August 2006.

[4] J. Lee, S. Sathiakumar, Y. Shrivastava, “A novel speed and position estimation of the brushless DC motor at low speed “Power Engineering Conference, AUPEC 2008. IEEE, vol. 3, pp. 1-6, December 2008.

[5] M. Divandari. R. Brazamini, A. Dadpour, M. Jazaeri, “A Novel Dynamic Observer and Torque Ripple Minimization via Fuzzy Logic for SRM Drives “International Symposium on Industrial Electronics, ISIE 2009. IEEE, vol. 1, pp. 847 – 852, July 2009.

Single Stage Solar PV Fed Brushless DC Motor Driven Water Pump

 

ABSTRACT:

In order to optimize the solar photovoltaic (PV) generated power using a maximum power point tracking (MPPT) technique, a DC-DC conversion stage is usually required in solar PV fed water pumping which is driven by a brushless DC (BLDC) motor. This power conversion stage leads to an increased cost, size, complexity and reduced efficiency. As a unique solution, this work addresses a single stage solar PV energy conversion system feeding a BLDC motor-pump, which eliminates the DC-DC conversion stage. A simple control technique capable of operating the solar PV array at its peak power using a common voltage source inverter (VSI), is proposed for BLDC motor control. The proposed control eliminates the BLDC motor phase current sensors. No supplementary control is associated for the speed control of motor-pump and its soft start. The speed is controlled through the optimum power of solar PV array. The suitability of proposed system is manifested through its performance evaluation using MATLAB/Simulink based simulated results and experimental validation on a developed prototype, under the practical operating conditions.

KEYWORDS:

  1. MPPT
  2. Solar PV array
  3. BLDC motor
  4. Water pump
  5. VSI
  6. Soft starting
  7. Speed control

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

 

Fig.1 Proposed water pumping based on a single stage solar PV energy conversion system.

EXPECTED SIMULATION RESULTS:

 Fig.2 Steady state and starting performance of (a) PV array and (b) motor pump, of proposed system at 1 kW/m2.

Fig.3 Steady state and starting response of (a) PV array and (b) motor-pump, of proposed system at 200 W/m2.

Fig.4 Dynamic performance of (a) PV array and (b) BLDC motor Pump ,of Proposed  water pumping system.

Fig. 5 Responses of (a) PV array and (b) BLDC motor, under partial shading

CONCLUSION:

The proposed BLDC motor driven water pumping based on a single stage solar PV generation has been validated through a demonstration of its various steady state, starting and dynamic performances. The system has been simulated using the MATLAB toolboxes, and implemented on an experimental prototype. The topology of the proposed system has provided a DC-DC converter-less solution for PV fed brushless DC motor driven water pumping. Moreover, the motor phase current sensing elements have been eliminated, resulting in a simple and cost-effective drive. The other desired functions are the speed control without any additional circuit and a soft start of the motor-pump. A detailed comparative analysis of the proposed and the existing topologies has ultimately manifested the superiority of the proposed work.

REFERENCES:

[1] C. Jain and B. Singh, “An Adjustable DC Link Voltage Based Control of Multifunctional Grid Interfaced Solar PV System,” IEEE J. Emerg. Sel. Topics Power Electron., Early Access.

[2] A. A. A. Radwan and Y. A. R. I. Mohamed, “Power Synchronization Control for Grid-Connected Current-Source Inverter-Based Photovoltaic Systems,” IEEE Trans. Energy Convers., vol. 31, no. 3, pp. 1023-1036, Sept. 2016.

[3] P. Vithayasrichareon, G. Mills and I. F. MacGill, “Impact of Electric Vehicles and Solar PV on Future Generation Portfolio Investment,” IEEE Trans. Sustain. Energy, vol. 6, no. 3, pp. 899-908, July 2015.

[4] A. K. Mishra and B. Singh, “A single stage solar PV array based water pumping system using SRM drive,” IEEE Ind. Appl. Soc. Annu. Meeting, Portland, OR, 2016, pp. 1-8.

[5] S. Jain, A.K. Thopukara, R. Karampuri and V.T. Somasekhar, “A Single-Stage Photovoltaic System for a Dual-Inverter-Fed Open-End Winding Induction Motor Drive for Pumping Applications,” IEEE Trans. Power Electron., vol. 30, no. 9, pp. 4809 – 4818, Sept. 2015.

BLDC Motor Driven Solar PV Array Fed Water Pumping System Employing Zeta Converter

ABSTRACT:

This paper proposes a simple, cost effective and efficient brushless DC (BLDC) motor drive for solar photovoltaic (SPV) array fed water pumping system. A zeta converter is utilized in order to extract the maximum available power from the SPV array. The proposed control algorithm eliminates phase current sensors and adapts a fundamental frequency switching of the voltage source inverter (VSI), thus avoiding the power losses due to high frequency switching. No additional control or circuitry is used for speed control of the BLDC motor. The speed is controlled through a variable DC link voltage of VSI. An appropriate control of zeta converter through the incremental conductance maximum power point tracking (INC-MPPT) algorithm offers soft starting of the BLDC motor. The proposed water pumping system is designed and modeled such that the performance is not affected under dynamic conditions. The suitability of proposed system at practical operating conditions is demonstrated through simulation results using MATLAB/ Simulink followed by an experimental validation.

KEYWORDS:

  1. BLDC motor
  2. SPV array
  3. Water pump
  4. Zeta converter
  5. VSI
  6. INC-MPPT

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

 

Fig.1 Configuration of proposed SPV array-Zeta converter fed BLDC motor drive for water pumping system.

EXPECTED SIMULATION RESULTS:

 

Fig.2 Performances of the proposed SPV array based Zeta converter fed BLDC motor drive for water pumping system (a) SPV array variables, (b) Zeta converter variables, and (c) BLDC motor-pump variables.

CONCLUSION:

The SPV array-zeta converter fed VSI-BLDC motor-pump for water pumping has been proposed and its suitability has been demonstrated by simulated results using MATLAB/Simulink and its sim-power-system toolbox. First, the proposed system has been designed logically to fulfil the various desired objectives and then modelled and simulated to examine the various performances under starting, dynamic and steady state conditions. The performance evaluation has justified the combination of zeta converter and BLDC motor drive for SPV array based water pumping. The system under study availed the various desired functions such as MPP extraction of the SPV array, soft starting of the BLDC motor, fundamental frequency switching of the VSI resulting in a reduced switching losses, reduced stress on IGBT switch and the components of zeta converter by operating it in continuous conduction mode and stable operation. Moreover, the proposed system has operated successfully even under the minimum solar irradiance.

REFERENCES:

[1] M. Uno and A. Kukita, “Single-Switch Voltage Equalizer Using Multi- Stacked Buck-Boost Converters for Partially-Shaded Photovoltaic Modules,” IEEE Transactions on Power Electronics, no. 99, 2014.

[2] R. Arulmurugan and N. Suthanthiravanitha, “Model and Design of A Fuzzy-Based Hopfield NN Tracking Controller for Standalone PV Applications,” Electr. Power Syst. Res. (2014). Available: http://dx.doi.org/10.1016/j.epsr.2014.05.007

[3] S. Satapathy, K.M. Dash and B.C. Babu, “Variable Step Size MPPT Algorithm for Photo Voltaic Array Using Zeta Converter – A Comparative Analysis,” Students Conference on Engineering and Systems (SCES), pp.1-6, 12-14 April 2013.

[4] A. Trejos, C.A. Ramos-Paja and S. Serna, “Compensation of DC-Link Voltage Oscillations in Grid-Connected PV Systems Based on High Order DC/DC Converters,” IEEE International Symposium on Alternative Energies and Energy Quality (SIFAE), pp.1-6, 25-26 Oct. 2012.

[5] G. K. Dubey, Fundamentals of Electrical Drives, 2nd ed. New Delhi, India: Narosa Publishing House Pvt. Ltd., 2009.

A Comparative Study of Speed Control of D.C. Brushless Motor Using PI and Fuzzy Controller

 

ABSTRACT:

This paper presents an intelligent control architecture for a sensor based brushless DC motor. A BLDC motor is superior to a brushed DC motor, as it replaces the mechanical commutation unit with an electronic one; hence improving the dynamic characteristics, efficiency and reducing the noise level marginally. Conventionally a PI-controller is used for speed control purpose in many industrial BLDC motor drives. But the accuracy level obtained by the PI-controlled drive is insufficient for advanced sophisticated applications. So as a better choice, a fuzzy logic control technique is applied to this motor to achieve a greater accuracy in controlling the speed.

KEYWORDS:

  1. Intelligent control
  2. BLDC motor
  3. Dynamic characteristics
  4. Accuracy
  5. Fuzzy logic

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAMS:

Fig. 1. Block diagram for speed control of BLDCM using PI controller.

Fig. 2. Block diagram of a fuzzy logic controlled BLDC motor drive.

 EXPECTED SIMULATION RESULTS:

                  Fig. 3. Speed response of PI controlled BLDC motor drive(Nref=1500 r.p.m)

Fig. 4. Speed response of fuzzy logic controlled BLDC motor drive (Nref=1500 r.p.m)

Fig. 5. Speed response of PI controlled BLDC motor drive(transition from 1500 r.p.m to 1400 r.p.m)

                         Fig. 6. Speed response of fuzzy logic controlled BLDC motor drive (transition from 1500 r.p.m to 1400 r.p.m)

CONCLUSION:

In this paper we discussed the BLDC motor speed control using a fuzzy logic controller. A detailed analysis was done on fuzzification, fuzzy rules and defuzzification methods and lookup table was obtained by using fuzzy algorithm. The PI control scheme and fuzzy based PI scheme were simulated using MATLAB and compared. The dynamic response of speed in using FLC was better than only PI scheme. These results show that a PI based FLC technique is a better choice for BLDC motor drive and favors to widen its area of application in near future.

REFERENCES:

[1] Paul C. Krause, “Analysis of electric machinary”, McGraw-Hill, 1984.

[2] P.S. Bimbhra, “ Generalized Theory of Electrical Machines”, Khanna Publishers.

[3] P. Yedamale, Brushless DC (BLDC) Motor Fundamentals. Application Note 885, Microchip Technology Inc., Chandler, AZ,2003.

[4] Dutta, P.; Mahato, S.N., “Design of mathematical model and performance analysis of BLBLDC motor,” Control, Instrumentation, Energy and Communication (CIEC), 2014 International Conference on , vol., no., pp.457,461, Jan. 31 2014-Feb. 2 2014

[5] Ko, J.S.; Jae Gyu Hwang; Myung-Joong Youn, “Robust position control of BLDD motors using integral-proportional plus fuzzy logic controller,” Industrial Electronics, Control, and Instrumentation, 1993. Proceedings of the IECON ’93., International Conference on , vol., no., pp.213,218 vol.1, 15-19 Nov 1993

A Comparative Study of PI, Fuzzy and Hybrid PI Fuzzy Controller for Speed Control of Brushless DC Motor Drive

ABSTRACT: 

This paper presents the comparative study between PI, fuzzy and hybrid PI-Fuzzy controller for speed control of brushless dc (BLDC) motor. The control structure of the proposed drive system is described. The simulation results of the drive system for different operation modes are evaluated and compared. A fuzzy controller offers better speed response for start-up while PI controller has good compliance over variation of load torque but has slow settling response. Hybrid controller has an advantage of integrating a superiority of these two controllers for better control performances. Matlab/Simulink is used to carry out the simulation.

KEYWORDS:
1. PI
2. Fuzzy
3. Hybrid Controller
4. BLDC Motor
5. Speed Control

SOFTWARE: MATLAB/SIMULINK

SIMULINK DIAGRAM:

Figure 1: Simulation model BLDC motor drive

EXPECTED SIMULATION RESULTS:

Figure 2: PI controller

Figure 3: Fuzzy controller

Figure 4: Hybrid controller

Figure 5: Comparison of speed response

Figure 6: PI controller

Figure 7: Fuzzy controller

Figure 8: Hybrid controller

Figure 9: Comparison of speed response

CONCLUSION:
From simulation results, it was shown that PI controller maintained the steady state accuracy while the fuzzy controller performed well in the case of sufficiently large reference input changes with shorter settling time. The hybrid controller has integrated both fuzzy controller and PI controller. During the large speed error, the fuzzy controller will be selected by switch. When the speed error is less than 0.28 rpm, the PI controller will be selected to maintain the high steady-state accuracy. The simulation results showed that the hybrid controller has incorporated advantage of both fuzzy and PI controller. As a conclusion, the hybrid controller has improved the dynamic performance of BLDC motor.
REFERENCES:
[1] F. Farkas, A. Zakharov and S.Z. Varga, “Speed and position controller for dc drives using fuzzy logic”, Studies in Applied Electromagnetics and Mechanics (Vol. 16): Applied Electromagnetics and Computational Technology II, Amsterdam: IOS Press, 2000.
[2] Zulkifilie Ibrahim and Emil Levi, “A comparative analysis of fuzzy logic and pi speed control in high-performance ac drives using experimental approach”, IEEE Trans. on Industry Applications 38(5): pg 1210-1218, 2002.
[3] L.S. Xuefang, F. Morel, A.M. Llor, B. Allard, J.-M. Retif, “Implementation of hybrid control for motor drives”, IEEE Trans. Industrial Electronics, vol.38, No. 5, pp. 1210-1218, Sep. 2002.
[4] Krishnan R, Permanent magnet synchronous and brushless DC motor drives, Boca Raton: CRC Press, 2010
[5] Lini Mathew and Vivek Kumar Pandey, “Design and deelopment of fuzzy logic controller to control the speed of permanent magnet synchronous motor”, JEEER, vol. 3(3), pp. 52-61, March 2011.

Reducing Torque Ripple of Brushless DC Motor by Varying Input Voltage

 

ABSTRACT

This paper presents the method of reducing torque ripple of brushless direct current (BLDC) motor. In the BLDC motor, the torque ripple is decided by the back-electromotive force (EMF) and current waveform. If the back-EMF is constant in the conduction region of current, the torque ripple depends on the current ripple. The period of freewheeling region in the conduction region can be acquired by circuit analysis using the Laplace transformation and the torque ripple can be also reduced by varying input voltage to reduce the current ripple. The suggested method to reduce the torque ripple is confirmed by the dynamic simulation with the parameters of 500W BLDC motor.

KEYWORDS

  1. BLDC motor
  2. Current ripple
  3. Torque ripple
  4. Varying input voltage

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

Fig. 1. PWM inverter and equivalent circuit of BLDC motor

EXPECTED SIMULATION RESULTS

Fig. 2. Back-EMF of 500 W BLDC motor at 6660 rpm.

Fig. 3. Current waveform of 500 W BLDC motor at 6660 rpm. (a) Experimental data. (b) Simulation data.

Fig. 4. Current and torque waveform in simulation. (a) Constant input voltage.

(b) Various input voltage..

 

CONCLUSION

This paper presents the method of reducing torque ripple of the BLDC motor by varying the input voltage after circuit analysis using the Laplace transformation. In the simulation confirmed by experiment, the torque ripple is reduced to 10%. The 500WBLDC motor used for simulation and experiment dose not have a trapezoidal back-EMF waveform but a sinusoidal back-EMF waveform. So the torque ripple is not reduced conspicuously, although the current ripple is reduced conspicuously, and produced torque ripple waveform is similar to the back-EMF waveform of 500 W BLDC motor.

REFERENCES

[1] J.-G. Lee, C.-S. Park, J.-J. Lee, G. H. Lee, H.-I. Cho, and J.-P. Hong, “Characteristic analysis of brushless motor condering drive type,” KIEE, pp. 589–591, Jul. 2002.

[2] T.-H. Kim and M. Ehsani, “Sensorless control of the BLDC motor from near-zero to high speeds,” IEEE Power Electron., vol. 19, no. 5, pp. 1635–1645, Nov. 2004.

[3] J. R. Hendershot Jr. and T. Miller, “Design of brushless permanent magnet motor,” in Oxford Magna Physics, 1st ed., 1994.

[4] P. Pillay and R. Krishnan, “Modeling, simulation, and analysis a permanent magnet brushless dc motor drive,” in Conf. Rec. 1987 IEEE IAS Annu. Meeting, San Diego, CA, Oct. 1–5, 1989, pp. 7–14.

[5] R. Carlson, M. Lajoie-Mazenc, and J. C. dos Fagundes, “Analsys of torque ripple due to phase commutation in brushless dc machines,” IEEE Trans. Ind. Appl., vol. 28, no. 3, pp. 632–638.

A New Approach to Sensorless Control Method for Brushless DC Motors

ABSTRACT:

This paper proposes a new position sensorless drive for brushless DC (BLDC) motors. Typical sensorless control methods such as the scheme with the back-EMF detection method show high performance only at a high speed range because the magnitude of the back-EMF is dependent upon the rotor speed. This paper presents a new solution that estimates the rotor position by using an unknown input observer over a full speed range. In the proposed method, a trapezoidal back-EMF is modelled as an unknown input and the proposed unknown input observer estimating a line-to-line back-EMF in real time makes it possible to detect the rotor position. In particular, this observer has high performance at a low speed range in that the information of a rotor position is calculated independently of the rotor speed without an additional circuit or complicated operation process. Simulations and experiments have been carried out for the verification of the proposed control scheme.

KEYWORDS:

  1. BLDC motor
  2. Full speed range
  3. Sensorless control
  4. Unknown input observer

 SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Overall structure of the proposed sensorless drive system.

EXPECTED SIMULATION RESULTS:

 Fig. 2. Response waveforms at under step change of load torque. (Speed reference: 50 rpm, Load: 0.2 → 0.5 Nm).

 

Fig. 3. Response waveforms under step change of load torque. (Speed reference: 1650 rpm, Load: 0.75 → 1.5 Nm).

 

Fig. 4. Response waveforms under step change of speed reference. (Load: 0.75 Nm, Speed reference: 50 → 1650 → 50 rpm).

CONCLUSION:

This paper presented a new approach to the sensorless control of the BLDC motor drives using the unknown input observer. This observer can be obtained effectively by using the equation of augmented system and an estimated line-to-line back- EMF that is modelled as an unknown input. As a result, the actual rotor position as well as the machine speed can be estimated strictly even in the transient state from the estimated line-to-line back-EMF.

The novel sensorless method using an unknown input observer can

  • be achieved without additional circuits.
  • estimate a rotor speed in real time for precise control.
  • make a precise commutation pulse even in transient state as well as in steady state.
  • detect the rotor position effectively over a full speed range, especially at a low speed range.
  • calculate commutation function with a noise insensitive.
  • be easily realized for industry application by simple control algorithm.

The simulation and experimental results successfully confirmed the validity of the developed sensorless drive technique using the commutation function.

REFERENCES:

[1] N. Matsui, “Sensorless PM brushless DC motor drives,” IEEE Trans. on Industrial Electronics, vol. 43, no. 2, pp. 300-308, 1996.

[2] K. Xin, Q. Zhan, and J. Luo, “A new simple sensorless control method for switched reluctance motor drives,” KIEE J. Electr. Eng. Technol., vol. 1, no. 1, pp. 52-57, 2006.

[3] S. Ogasawara and H. Akagi, “An approach to position sensorless drive for brushless DC motors,” IEEE Trans. on Industry Applications, vol. 27, no. 5, pp. 928-933, 1991.

[4] J. C. Moreira, “Indirect sensing for rotor flux position of permanent magnet AC motors operating over a wide speed range,” IEEE Trans. on Industry Applications, vol. 32, no. 6, pp. 1394-1401, 1996.

[5] J. X. Shen, Z. Q. Zhu, and D. Howe, “Sensorless flux-weakening control of permanent-magnet brushless machines using third harmonic back EMF,” IEEE Trans. on Industry Applications, vol. 40, no. 6, pp. 1629-1636, 2004.

Solar PV Array Fed Brushless DC Motor Driven Water Pump

 

ABSTRACT:

 This work deals with the utilization of solar photovoltaic (SPV) energy in the brushless DC (BLDC) motor driven water pump. A DC-DC boost converter, used as an intermediate power conditioning unit plays a vital role in efficiency enhancement of SPV array and soft starting of the BLDC motor with proper control. The speed control of BLDC motor is performed by PWM (Pulse Width Modulation) control of the voltage source inverter (VSI) using DC link voltage regulator. No additional control or current sensing element is required for speed control. The behavior of proposed pumping system is demonstrated by evaluating its various performances through MATLAB/simulink based simulation study.

KEYWORDS:

  1. Solar PV
  2. BLDC motor
  3. Boost converter
  4. Soft starting
  5. PWM
  6. VSI
  7. Speed control

 SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig.1 Configuration of PV array fed BLDC motor-pump.

 EXPECTED SIMULATION RESULTS:

 

Fig.2 Starting and steady state performances of solar PV array

Fig.3 Starting and steady state performance of boost DC-DC converter

Fig.4 Starting and steady state performance of brushless DC motor-pump

Fig.5 Dynamic performance of solar PV array.

Fig.6 Dynamic performance of boost DC-DC converter

Fig.7 Dynamic performance of brushless DC motor – pump

CONCLUSION:

The SPV Array fed boost converter based BLDC motor driven water pump has been proposed and its suitability has been demonstrated by analyzing its various performance indices using MATLAB based simulation study. A simple, efficient and economical method for speed control of BLDC motor has been suggested, which has offered absolute elimination of current sensing elements. The proper selection of SPV array has made the boost converter capable of tracking MPP irrespective of weather conditions. An optimum design of the boost converter has been presented. The safe starting of brushless DC motor has been achieved without any additional control. The desired performance of proposed system even at 20% of standard solar irradiance has justified its suitability for solar PV based water pumping.

REFERENCES:

[1] R. Kumar and B. Singh, “Solar PV array fed Cuk converter-VSI controlled BLDC motor drive for water pumping,” 6th IEEE Power India Int. Conf. (PIICON), 5-7 Dec. 2014, pp. 1-7.

[2] M. A. Elgendy, B. Zahawi and D. J. Atkinson, “Assessment of the Incremental Conductance Maximum Power Point Tracking Algorithm,” IEEE Trans. Sustain. Energy, vol.4, no.1, pp.108-117, Jan. 2013.

[3] J.V. Mapurunga Caracas, G. De Carvalho Farias, L.F. Moreira Teixeira and L.A. De Souza 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] N. Mohan, T. M. Undeland and W. P. Robbins, Power Electronics: Converters, Applications and Design, 3rd ed. New Delhi, India: John Wiley & Sons Inc., 2010.

[5] M. H. Rashid, Power Electronics Handbook: Devices, Circuits, and Applications,” 3rd ed. Oxford, UK: Elsevier Inc., 2011.

 

Analysis of PFC Cuk and PFC Sepic Converter Based Intelligent Controller Fed BLDC Motor Drive

ABSTRACT

This paper deals with a highly reliable electrical drive utilizing the Brushless DC Motor (BLDC). The motor is fed by Voltage source Inverter (VSI) with a dc-dc converter power factor correction circuit (PFC) as the VSI’s predecessor. The Performance of two dc-dc converters (cuk and sepic as PFC) are analyzed and the results are discussed to arrive at the best suited converter. Fuzzy Logic Controller is used as the Intelligent Controller for the BLDC motor. Reliable, low cost arrangement is thus provided to achieve unity power factor and speed regulation with accuracy. The drive has been simulated using the MATLAB/Simulink environment and the performance has been studied. 

KEYWORDS:

  1. Brushless DC Motor (BLDC)
  2. Power Quality (PQ)
  3. Power factor correction (PFC)
  4. Cuk converter
  5. Sepic converter
  6. Fuzzy logic controller (FLC).

SOFTWARE: MATLAB/SIMULINK 

BLOCK  DIAGRAM:

 Block diagram

PFC Cuk PFC Sepic converter Fed BLDC Motor

Fig. 1. Block diagram

SIMULINK MODEL DIAGRAMS:

PFC cuk fed BLDC

PFC Cuk PFC Sepic converter Fed BLDC Motor

Fig. 2. PFC cuk fed BLDC

 PFC Sepic fed BLDC

Fig. 3. PFC Sepic fed BLDC

EXPECTED SIMULATION RESULTS:

 Input power factor

PFC Cuk PFC Sepic converter Fed BLDC Motor

 

Fig. 4. Input power factor

Cuk Converter Efficiency

PFC Cuk PFC Sepic converter Fed BLDC Motor

Fig. 5. Cuk Converter Efficiency

Motor Speed

PFC Cuk PFC Sepic converter Fed BLDC Motor

Fig. 6. Motor Speed

Input power factor

Fig. 7. Input power factor

Sepic Converter Efficiency

PFC Cuk PFC Sepic converter Fed BLDC Motor

Fig. 8. Sepic Converter Efficiency

Motor Speed

PFC Cuk PFC Sepic converter Fed BLDC Motor

Fig. 9. Motor Speed

CONCLUSION

The power factor correction has been successfully implemented using the cuk and sepic converter. It shows a much improved result as it not only provides better power quality, but also the converter removes the necessity to smooth out the dc output from ripples. The fuzzy logic controller widely increases application range of the motor by increasing the reliability. The motor is presently used in areas such as aerospace, aircraft and mining applications because of the enhanced reliability that the motor offers. This is further enhanced by the usage of FLC and the PFC converters. The FLC is used to control the motor speed and the cuk or sepic converter is used for the power factor improvement. It is found that the sepic converter is found to provide better power quality. The Analysis has been done for Continuous conduction in the sepic and cuk converters as both are not capable of self PFC.

REFERENCES

  1.  Shanmugasundram, K. Muhammad Zakariah and N. Yadaiah, “Implementation and Performance Analysis of Digital Controllers for Brushless DC Motor Drives,” IEEE/ASME Trans. Mechatronics, vol. 19, no. 1, Feb. 2014.
  2. Kenjo and S. Nagamori, Permanent Magnet Brushless DC Motors.Oxford, U.K.: Clarendon Press, 1985.
  3. Sanjeev Singh and Bhim Singh, “A Voltage-Controlled PFC Cuk Converter-Based PMBLDCM Drive for Air-Conditioners,” IEEE Trans. Ind. Appl. 48, no. 2, Mar. /Apr. 2012.
  4. Vashist Bist and Bhim Singh, “PFC CUK Converter-Fed BLDC Motor Drive,” IEEE Trans. Power Electron., vol. 30, no 2, Feb. 2015.
  5. “Limits for harmonic current emissions (equipment input current16 A per phase),” International Standard IEC 61000-3-2, 2000