Analysis Of Solar Energy Embeded To Distribution Grid For Active & Reactive Power Supply To Grid

ABSTRACT:

This paper presents a system of grid connected photovoltaic (PV) to the monitoring point of maximum power (MPPT). The voltage source inverter (VSI) is connected between the dc output of photovoltaic system and ac grid. The control strategy applied is based on theory of instantaneous reactive power (p-q theory). According to this proposed PV system send active power to the grid at the same time the reactive power of load and harmonics will eliminate at change in both irradiation and load condition. During no sunlight system is available only reactive power and harmonic compensation. The applicability of our system tested in simulation in Matlab / Simulink.

KEYWORDS:

1.      Grid-connected PV system

2.      Instantaneous reactive power theory

3.      MPPT

4.      Reactive power compensation

5.      Power quality

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Proposed Grid Connected PV System

EXPECTED SIMULATION RESULTS:

Fig. 2. Active Power of load, PV system and grid

Fig. 3. Reactive Power of load, PV system and grid

Fig. 4. Current of Load, PV Inverter and Grid

                  

Fig. 5. Harmonic analysis with and without PV system

Fig. 6 Waveform of Grid Volatge and Current

CONCLUSION:

Photovoltaic power seems to be the favorable clean energy source of the future. So, to optimize its use we have proposed a direct coupling of PV system to the grid. From the results obtained, it is proven that by using the proposed system, Photovoltaic power can be efficiently extracted by solar cells and injected into the grid and compensating reactive power of the load all 24 h of the day. The proposed system also compensates the harmonics content of nonlinear load. Finally, and according to the obtained results we can consider the proposed system to be efficient solution to the growing demand of power at the present and in the future.

REFERENCES:

[1] Pandiarajan N, Ramaprabha R and RanganathMuthu. “Application of Circuit Model for Photovoltaic Energy Conversion System” INTERNATIONAL CONFERENCE’2010.

[2] Marcelo GradellaVillalva, Jonas Rafael Gazoli, Ernesto RuppertFilho, “Modeling And Circuit-based Simulation of Photovoltaic Arrays” 10^TH Brazilian Power Electronics Conference (COBEP), pp.1244-1254, 2009.

[3] SoerenBaekhoejKjaer, John K. Pedersen FredeBlaabjerg “A Review of Single-Phase Grid-Connected Inverters for Photovoltaic Modules” IEEE Transactions On Industry Applications, 41(5), pp.1292-1306, 2005.

[4] FredeBlaabjerg, ZheChen,SoerenBaekhoejKjaer, “Power Electronics as Efficient Interface in Dispersed Power Generation Systems” IEEE Transactions On Power Electronics, 19(5)1184-1194, 2004.

[5] D. Picault, B. Raison, and S. Bacha “Guidelines for evaluating grid connected PV system topologies”. IEEE International Conference on Industrial Technology1-5, 2009.

Reduction of Commutation Torque Ripple in a Brushless DC Motor Drive

ABSTRACT :

This paper describes the reduction in torque ripple due to phase commutation of brushless dc motors. With two-phase 120⁰ electrical conduction for the inverter connected to the conventional three-phase BLDC machine, the commutation torque ripple occurs at every 60 electrical degrees when a change over from one phase to another occurs. This effect increases the commutation time at higher speeds which increases the torque ripple. The torque ripple is reduced by changing the switching mode from 120⁰ to a dual switching mode with 120⁰ switching at lower speeds and 180⁰ electrical for the inverter at higher speeds.

KEYWORDS:

1.      Brushless dc motor

2.      Current commutation

3.      Torque ripple

4.      Electric vehicle

     SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

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

EXPECTED SIMULATION RESULTS:

Fig.2. (a) Relative torque ripple amplitude and (b) The duration of

commutation time

CONCLUSION:

This paper has presented an analytical study of torque ripple comparison due to commutation of phase currents in a brushless dc motor for both 1200 and 1800 conduction modes. The results have been validated by simulation and experimental verification. In three-phase switching mode at high speeds the torque ripple and losses are minimized and therefore the efficiency of the machine is increased. But the same cannot be achieved at low speed in this mode. On the other hand, the 1200 situation is exactly opposite. Thus a composite switching scheme is proposed for satisfactory operation of the machine at all speeds. The effectiveness of the method is validated by suitable experiments.

REFERENCES:

[1] T. Li, and G. Slemon, “Reduction of cogging torque in permanent magnet motors,” IEEE Trans. on Magnetics, vol.24, no.6, pp.2901-2903, Nov. 1988.

[2] R. Carlson, M. Lajoie-Mazenc, and J.C.D.S. Fagundes, “Analysis of torque ripple due to phase commutation in brushless DC machines,” IEEE Trans. Ind. Appl., vol.28, no.3, pp. 632-638, May/Jun. 1992.

[3] H. Tan, “Controllability analysis of torque ripple due to phase commutation in brushless DC motors,” in Proc. 5th int. conf. Elect. Mach. And Syst., Aug. 18-20, 2001, vol.2, pp. 1317-1322.

[4] Y. Murai, Y. Kawase, K. Ohashi, K. Nagatake and K. Okuyama, “Torque ripple improvement for brushless DC miniature motors,” IEEE Trans. Ind. Appl., vol.25, no.3, pp. 441-450, May/Jun. 1989.

[5] C.S. Berendsen, G. Champenois, and A. Bolopion, “Commutation strategies for brushless DC motors: Influence on instant torque,” IEEE Trans. Power Electron., vol.8, no.2, pp. 231-236, Apr.1993.

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.

Model and system simulation of Brushless DC motor based on SVPWM control

ABSTRACT:

According to the disadvantages as large torque ripple of square wave drive brushless DC motor control system, this paper adopted the sine wave drive the permanent magnet brushless DC motor control system based on the space vector pulse width modulation (SVPWM) control method. The simulation model of space vector pulse width modulation control method of the rotated speed of brushless DC motor and current double closed-loop control system is simulated and analyzed in MATLAB/SIMULINK. The simulation results have verified the reasonability and validity of the simulation model.

KEYWORDS:

1.      Brushless DC motor

2.      Modeling and simulation

3.       Space vector pulse width modulation (SVPWM)

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Figure 1 The overall system block diagram of BLDCM control system

EXPECTED SIMULATION RESULTS:

Figure 2 Speed information

Figure 3 Torque waveform

Figure 4 The motor stator three-phase current waveform

Figure 5 Phase A current use PWM and SVPWM control

 CONCLUSION:

In this paper, the SVPWM control of BLDCM simulation model is established based on the MATLAB/SIMULINK, and used the classic speed, current double closed-loop PI control algorithm. From the output waveform, it can be seen the system corresponding speed fast, quickly achieve steady state. Plus load torque at t=0.1s, the speed happen fell but return to equilibrium state at soon. Three phase stator current waveform as nearly as sine wave. The simulation results show that the SVPWM control of BLDCM has good static and dynamic characteristics.

REFERENCES:

[1]Wu Quan-li, Huang Hong-quan. Simulation study of penmanent maagnet brushless DC motor based on PWM control. Electrical switches, Vol.5 (2010), p. 39-41

[2]Ma Ruiqing, Deng Junjun. Research on characteristic of sinusoidal current driving method for

BLDCM with hall position sensor. Micro-motor, Vol.7 (2011), p. 59-61

[3]Wang Shuhong. A control strategy of PMDC brushless motor based on SVPWM. Automation

Expo, Vol.10 (2008), p. 66-68

[4]Qiu Jianqi. SVPWM control for torque ripple attenuation of PM brushless DC motors. Small and medium-sized motor. Vol.2 (2003), p. 27-28

[5]Boyang Hu.180-Degree Commutation System of Permanent Magnet Brushless DC Motor Drive Based on Speed and Current Control.2009 Sencond International Conference on Intelligent Computation Technology and Automation,Vol.2 (2009), p. 723-726

Hybrid converter topology for reducing torque ripple of BLDC motor

ABSTRACT

This study investigates the torque ripple performance of brushless DC (BLDC) motor drive system by integrating bothmodified single-ended primary inductor converter (SEPIC) and silicon carbide metal–oxide–semiconductor field-effect transistorbased three-level neutral-point-clamped (NPC) inverter. In BLDC motor, the high commutation torque ripple is an importantorigin of vibration, speed ripple and prevents the use of the BLDC motor drive system in high-performance and high-precisionapplications. For torque ripple reduction, the modified SEPIC converter is employed at the entrance of the three-level NPCinverter, which regulates the DC-link voltage according to the motor speed. Moreover, the three-level NPC inverter is employedas a second-stage converter to suppress current ripple for further torque ripple reduction. Finally, the performance of theproposed hybrid converter topology is verified by simulation and laboratory experimental results.

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

(a) Proposed converter topology

EXPECTED SIMULATION RESULTS

Fig. 2Phase current and torque waveforms

(a) Phase current and torque waveforms from simulation at 2500 rpm and 0.825 N m, (b) Phase current and torque waveforms from simulation at 2500 rpm and 0.825 N m, (c) Phase

current and torque waveforms from simulation at 6000 rpm and 0.825 N m, (d) Phase current and torque waveforms from simulation at 6000 rpm and 0.825 N m

CONCLUSION

A novel hybrid circuit topology has been proposed in this paperwhich is built by a modified SEPIC converter and a SiC-MOSFETbasedthree-level NPC converter for minimising torque ripple in aBLDC motor drive system. For efficient reduction of torque ripple,the first stage is the modified SEPIC converter that lifts the DClinkvoltage to the desired value based on the motor speedmeasurement. For further torque ripple reduction, the three-levelNPC inverter is employed as the second-stage converter tosuppress current ripple. Experimental results show that theproposed hybrid converter topology can suppress the torque rippleto 14.6% at the speed of 6000 rpm, commutation torque ripple isreduced substantially and produce smooth torque waveform thanthe BLDC motor driven by the two-level, three-level NPC, twolevelinverter with DC-link voltage control, and two-level inverterwith SEPIC converter and switch selection circuit topologies.

REFERENCES

[1] Singh, B., Bist, V.: ‘An improved power quality bridgeless Cuk converter fedBLDC motor drive for air conditioning system’, IET Power Electron., 2013,6, (5), pp. 902–913

[2] Carlson, R., Lajoie-Mazenc, M., Fagundes, J.C.D.S.: ‘Analysis of torqueripple due to phase commutation in brushless dc machines’, IEEE Trans. Ind.Appl., 1992, 28, (3), pp. 632–638

[3] Lee, S.K., Kang, G.H., Hur, J., et al.: ‘Stator and rotor shape designs ofinterior permanent magnet type brushless DC motor for reducing torquefluctuation’, IEEE Trans. Magn., 2012, 48, pp. 4662–4665

[4] Seo, U.J., Chun, Y.D., Choi, J.H., et al.: ‘A technique of torque ripplereduction in interior permanent magnet synchronous motor’, IEEE Trans.Magn., 2011, 47, (10), pp. 3240–3243

[5] Murai, Y., Kawase, K., Ohashi, K., et al.: ‘Torque ripple improvement forbrushless DC miniature motors’, IEEE Trans. Ind. Appl., 1989, 25, (3), pp.441–450

High-performance multilevel inverter drive of brushless DC Motor

ABSTRACT:

The brushless DC (BLDC) motor has numerous applications in high-power systems; it is simple in construction, is cheap, requires less maintenance, has higher efficiency, and has high power in the output unit. The BLDC motor is driven by an inverter. This paper presents design and simulation for a three-phase three-level inverter to drive the BLDC motor. The multilevel inverter is driven by discrete three-phase pulse width modulation (DPWM) generator that forced-commuted the IGBT’s three-level converters using three bridges to vectored outputs 12- pulses with three levels. Using DPWM with a three-level inverter solves the problem of harmonic distortions and low electromagnetic interference. This topology can attract attention in high-power and high-performance voltage applications. It provides a three-phase voltage source with amplitude, phase, and frequency that are controllable. The proposed model is used with the PID controller to follow the reference speed signal designed by variable steps. The system design is simulated by using Matlab/Simulink. Satisfactory results and high performance of the control with steady state and transient response are obtained. The results of the proposed model are compared with the variable DC-link control. The results of the proposed model are more stable and reliable.

KEYWORDS:

1.      Brushless DC Motor

2.      Multilevel Inverter

3.      High-Performance Drive

4.      Pulse Width Modulation (PWM)

5.      Maltlab

6.      Simulink

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

Figure 1. BLDC motor with MLI driven with PID controller.

EXPECTED SIMULATION RESULTS:

Figure. 2. Output of three-phase three-level inverter with DPWM.

Figure 3. The sample from output of the DPWM

Figure 4. Analysis of response for the proposed MLI with PID controller of BLDC motor.

Fig. 5. Two outputs of controllers with proposed MLI and variable DC-link

CONCLUSION:

The proposed MLI performance analysis was successfully presented by using Matlab/Simulink software. The proposed topology can be easily extended to a higher-level inverter. The simulation results were sine waves and exhibited fewer ripples and low losses. This system would show its feasibility in practice. The vector control was described in adequate detail and was implemented with a three-level MLI. This method enabled the operation of the drive at zero direct axis stator current. Transient results were obtained when a DPWM was started from a standstill to a required speed. The performance of the vector control in achieving a fast reversal of PDPWM even at very high speed ranges is quite satisfactory. The performance of the proposed three-phase MLI was investigated and was found to be quite satisfactory. A comparison was made between the PID controller–based proposed model MLI and the controller with variable DC-link voltage. The results showed that the proposed model responded better in transient and steady states and was more reliability with high performance.

REFERENCES:

 [1] P. D. Kiran, M. Ramachandra, “Two-Level and Five-Level Inverter Fed BLDC Motor Drives”, International Journal of Electrical and Electronics Engineering Research, Vol. 3, Issue 3, pp 71-82, Aug 2013

[2] N. Karthika, A. Sangari, R. Umamaheswari , “Performance Analysis of Multi Level Inverter with DC Link Switches for Renewable Energy Resources”, International Journal of Innovative Technology and Exploring Engineering, Volume-2, Issue-6, pp 171-176, May 2013

[3] A. Jalilvand R. Noroozian M. Darabian, “Modeling and Control Of Multi-Level Inverter for Three-Phase Grid-Connected Photovoltaic Sources”, International Journal on Technical and Physical Problems of Engineering, Iss. 15, Vol. 5, No.2, pp 35-43, June 2013

[4] P. Karuppanan, K. Mahapatra, “PI, PID and Fuzzy Logic Controlled Cascaded Voltage Source Inverter Based Active Filter For Power Line Conditioners”, Wseas Transactions On Power Systems, Issue 4, Volume 6, pp 100-109, October 2011

[5] D. Balakrishnan, D. Shanmugam, K.Indiradevi, “Modified Multilevel Inverter Topology for Grid Connected PV Systems”, American Journal of Engineering Research, Vol. 02, Iss.10, pp-378-384, 2013