Direct Torque Control of Induction Motors with Fuzzy Minimization Torque Ripple

Direct Torque Control of Induction Motors with Fuzzy Minimization Torque Ripple

ABSTRACT

Direct torque control (DTC) is a new method of induction motor control. The key issue of the DTC is the strategy of selecting proper stator voltage vectors to force stator flux and developed torque within a prescribed band. Due to the nature of hysteresis control adopted in DTC, there is no difference in control action between a larger torque error and a small one. It is better to divide the torque error into different intervals and give different control voltages for each of them. To deal with this issue a fuzzy controller has been introduced. But, because the number of rules is too high some problems arise and the speed of fuzzy reasoning will be affected. In this paper, a comparison between a new fuzzy direct-torque control (DTFC) with space vector modulation (SVM) is made. The principle and a tuning procedure of the fuzzy direct torque control scheme are discussed. The simulation results, which illustrate the performance of the proposed control scheme in comparison with the fuzzy hysteresis connected of DTC scheme are given.

KEYWORDS

1.      Induction machine

2.      Direct torque control

3.      Fuzzy logic

4.      Space vector modulation

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. A novel direct torque control scheme for ac motor drives (DTC) with fuzzy hysteresis and space vector modulation

CONCLUSION:

In this paper, a fuzzy direct torque control with space vector modulation is analyzed in comparison to fuzzy hysteresis connected of DTC. The results obtained by numerical simulation are given. In short, the advantages of proposed fuzzy direct torque control using space vector modulation technique in comparison with a fuzzy hysteresis of DTC are the following:

– Reduced torque and flux distortion;

– Constant switching frequency thanks to apply SVM;

– Fast torque response because of the use of fuzzy controller;

– Lower sampling time;

– No problems during Low-speed operation;

– No current and torque distortion caused by sector changes.

REFERENCES:

[1] Casadei, D., serra, G., Tani, A, «Performance analysis of a DTC control scheme for induction motor in the low speed range», in proceeding of EPE, (1997), p.3.700-3.704, Trondheim.

[2] Depenbrok. M, «Direct self-control (DSC) of inverter fed induction machine», In: IEEE Trans. On PE (1988), Vol. PE-3, No4, October 1988, p 420-429.

[3] A. Cataliotti, G. Poma: “A Fuzzy approach for easy and robust control of an induction motor”. EPE 97, pp 2.421-2.425, 1997.

[4] J. R G Schonfield,”Direct torque control-DTC", ABB Industrial Systems Ltd.

[5] Ned Gulley, J.-S. Roger Jang: Fuzzy Logic Toolbox for Use With Matlab". The Math Works inc, Natick, Mass, 1996.

Study On Speed Sensorless SVM-DTC System Of PMSM

Study On Speed Sensorless SVM-DTC System Of PMSM

ABSTRACT

A novel speed sensorless direct torque control system-SVM-DTC of permanent magnet synchronous motor (PMSM) based on SVM and MRAS is presented. In this paper the various components of the speed sensorless SVM-DTC and the principle of realization are discussed in detail. Finally the simulation results with the application of MATLAB/SIMULINK show that the speed identification algorithm is accurate and of robustness, moreover, the whole control system has good static and dynamic performances.

KEYWORDS:

1.      Permanent magnet synchronous motor (PMSM)

2.      Space Vector Modulation (SVM)

3.      Direct torque control (DTC)

4.      Model reference adaptive system (MRAS)

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig.1. Speed-sensor less SVM-DTC diagram.

CONCLUSION:

In this paper, the speed sensorless SVM-DTC system based on SVM and MRAS is presented and the control system has a clear control principle and structure. Simulation results show that the speed identification algorithm can estimate accurately the real speed and has robustness to varying of stator resistor. Moreover the speed sensorless SVM-DTC system has good static and dynamic performance.

REFERENCES:

[1] Yen-Shin Lai, Jian-Ho Chen..A New Approach to Direct Torque Control of Induction Motor Drives for Constant Inverter Switching Frequency and Torque Ripple Reduction[J],IEEE Transactions on Energy Conversion,2001,16(3),220-227

[2] Liang yan, Li Yongdong. The state of art of sensor-less vector control of PMSM[J]. Electric Drive,2003,33(4):4-9

[3] Young Sam Kim, Sang Kyoon Kim,Young Ahn Kwon.MRAS Based Sensorless Control of Permanent Magnet Synchronous Motor[C]. SICE Annual Conference, Fukui, Japan, 2003:1632-1637

[4] Li Yongdong. AC motor digital control system [M]. Beijing: Machine Press,2002

[5] Li Su. Direct Torque Control of Induction Motor[M]. Beijing: Machine Press,1999

A Non-Insulated Step-Up/Down DC-DC Converter with Wide Range Conversion

A Non-Insulated Step-Up/Down DC-DC Converter with Wide Range Conversion

ABSTRACT:

 In this paper an approach of a step-up/down dc-dc converter with wide range conversion called Boost²-Buck is presented. The proposed converter presents non pulsating input and output current. It has operations equivalent to a cascade converter consisting of two boost converter and one buck converter, but with the advantage of using single active switch. Mathematical analysis and experimental results are presented for converter operating with output power of 20W.

KEY WORDS:

1. Buck-Boost converters
2. converters

SOFTWARE: MATLAB/SIMULINK

  

CIRCUIT DIAGRAM:

                                                   

   Fig: 1 Schematic boost²-buck.

CONCLUSION:

The boost²-buck converter presented in this paper provides a wide range of dc conversion when compared with the conventional non-insulated dc-dc converters. This topology presents non pulsating input and output current. It has operations equivalent to a cascade converter consisting of two boost converter and one buck converter, but with the advantage of using single active switch. Consequently, when compared with a converter cascade, it is cheaper, less bulky and uses circuit control simpler. Through the experimental results is possible to prove the performance of the converter as well as the theoretical analysis presented.

  

REFERENCES:

[1] J. A. Morales-Saldaña, J. Leyva-Ramos, E. E. Carbajal-Gutiérrez, M. G. Ortiz-Lopez, “Average Current-Mode Control Scheme for a Quadratic Buck Converter with a Single Switch,” IEEE Trans. on Power Electronics, vol. 23, pp. 485–490, Jan. 2008.

[2] J. R. de Britto, A. E. Demian Jr., E. A. A. Coelho, L. C. de Freitas, V. J. Farias, J. B. Vieira Jr., “A Proposal of Led Lamp Driver for Universal Input Using Cuk Converter,” IEEE 39th Power Electronics Specialists Conference, Rhoedes, 2008.

[3] J. R. de Britto, A. E. Demian Jr., E. A. A. Coelho, L. C. de Freitas, V. J. Farias, J. B. Vieira Jr., “LED Lamp Driver Using a Converter with Wide Range Conversion Microcontroller-Based,” 34th Annual Conference of the IEEE Industrial Electronics Society (Accepted), Orlando, 2008.

[4] J. A. Morales-Saldaña, J. Leyva-Ramos, E. E. Carbajal-Gutiérrez, “Modeling of Switch-Mode DC-DC Cascade Converters,” IEEE Trans. on Aerospace and Electronic Systems, vol. 38, pp. 295–299, Jan. 2002.

[5] D. Maksimovic, S. Cuk, “Switching Converters with Wide DC Conversion Range,” IEEE Trans. on Power Electronics, vol. 6, pp. 151–157, Jan. 1991.

A Three-Level Full-Bridge Zero-Voltage Zero-Current Switching Converter With A Simplified Switching Scheme

ABSTRACT:

Multilevel dc–dc converters making use of high frequency transformers are suitable for integration in solid-state solutions for applications in electric power distribution systems. This paper presents a simplified switching scheme for three-level full-bridge dc–dc converters that enables zero-voltage and zero current switching of all the main power devices. It describes the main operational modes and design equations of the converter as well as provides simulation and experimental results to demonstrate the feasibility of the proposed ideas.

  

KEYWORDS:

1.      Distributed energy resources

2.      multilevel converters

3.      soft-switching converters

4.      three-level (3L) full bridge (FB)

5.      zero-voltage zero-current switching (ZVZCS)

SOFTWARE: MATLAB/SIMULINK

  

BLOCK DIAGRAM:

Fig.1. 3L FB ZVZCS converter. (a) Schematic

CONCLUSION:

This paper proposed a 3L ZVZCS converter with a simplified switching scheme for use in solid-state solutions. The converter was shown to have the advantages of soft switching and reduced voltage stresses across the devices, allowing higher voltage operation. The operation of the 3L FB ZVZCS converter was analyzed. Experimental results further demonstrated the feasibility of the proposed ideas. Future research would include designing a prototype to implement an active clamp to reset the current thus eliminating the series diodes and the losses associated with them. This would have the added benefit of reducing the spikes from the rectifier diodes when the dc voltage is applied during modes 1 and 6.

REFERENCES:

[1] F. Blaabjerg, Z. Chen, and S. B. Kjaer, “Power electronics as efficient interface in dispersed power generation systems,” IEEE Trans. Power Electron., vol. 19, no. 5, pp. 1184–1194, Sep. 2004.

[2] J. D. Leeper and J. T. Barich, “Technology for distributed generation in a global market place,” in Proc. Amer. Power Conf., 1998, vol. 1, pt. 1, pp. 33–36.

[3] E. R. Ronan, S. D. Sudhoff, S. F. Glover, and D. L. Galloway, “A power electronic-based distribution transformer,” IEEE Trans. Power Del., vol. 17, no. 2, pp. 537–543, Apr. 2002.

[4] L. M. Tolbert and F. Z. Peng, “Multilevel converters as a utility interface for renewable energy systems,” in Proc. 2000 Power Eng. Soc. Summer Meeting, 2000, vol. 2, pt. 2, pp. 1271–1274.

[5] A. Nabae, I. Takahashi, and H. Akagi, “A new neutral point clamped PWM inverter,” IEEE Trans. Ind. Appl., vol. IA-17, no. 5, pp. 518–523, Sep./Oct. 1981.

A Modular Fuel Cell, Modular DC–DC Converter Concept for High Performance and Enhanced Reliability

ABSTRACT:

Fuel cell stacks produce a dc output with a 2:1 variation in output voltage from no-load to full-load. The output voltage of each fuel cell is about 0.4 V at full-load, and several of them are connected in series to construct a stack. An example 100 V fuel cells tack consists of 250 cells in series and to produce 300 V at full load requires 750 cells stacked in series. Since fuel cells actively convert the supplied fuel to electricity, each cell requires proper distribution of fuel, humidification, coupled with water/their mal management needs. With this added complexity, stacking more cells in series decreases the reliability of the system. For example, in the presence of bad or mal performing cell/cells in a stack, uneven heating coupled with variations in cell voltages may occur.

Continuous operation under these conditions may not be possible or the overall stack output power is severely limited. In this paper, a modular fuel cell powered by a modular dc–dc converter is proposed. The proposed concept electrically divides the fuel cell stack into various sections, each powered by a dc–dc converter. The proposed modular fuel cell powered by modular dc–dc converter eliminates many of these disadvantages, resulting in a fault tolerant system. A design example is presented for a 150-W, three-section fuel cell stack and dc–dc converter topology. Experimental results obtained on a 150-W, three-section proton exchange membrane (PEM) fuel cell stack powered by a modular dc–dc converter are discussed

KEYWORDS:

1.      DC–DC converters

2.      fuel cells

3.      Power conditioning renewable power

 SOFTWARE: MATLAB/SIMULINK

SCHEMATIC DIAGRAM:

  

                                  Fig: 1 Proposed modular fuel cell and modular dc–dc converter concept

CONCLUSION:

In this paper, a modular fuel cell stack and dc–dc converter concept has been presented. It has been shown that the standard fuel cell stack can be reconfigured into several sections with smaller cell count, each supplying an isolated power module in the dc–dc converter, resulting in a high-performance system. The proposed system has been shown to be fault tolerant and can continue to operate at a reduced power level under fuel cell or power module faults. Experimental results on a 12-V/150-W system demonstrate that under normal operation, the proposed system is capable of producing 10% additional power when compared to the traditional approach. In addition, experimental results also confirm the operation of the system under stack failure.

 REFERENCES:

[1] L. Palma and P. Enjeti, “A modular fuel cell, modular DC–DC converter concept,” Texas A& M University, College Station, TAMUS 2431 Invention disclosure, Sep. 2006.

[2] M. Ellis, M. Spakovsky, and D. Nelson, “Fuel cell systems: Efficient, flexible energy conversion for the 21st century,” Proc. IEEE, vol. 89, no. 12, pp. 1808–1818, Dec. 2001.

[3] R. Gopinath, K. Sangsun, H. Jae-Hong, P. N. Enjeti, M. B. Yeary, and J. W. Howze, “Development of a low cost fuel cell inverter system with DSP control,” IEEE Trans. Power Electron., vol. 19, no. 5, pp. 1256–1262, Sep. 2004.

[4] R.-J. Wai and R.-Y. Duan, “High-efficiency power conversion for low power fuel cell generation system,” IEEE Trans. Power Electron., vol. 20, no. 4, pp. 847–856, Jul. 2005.

[5] B. Bouneb, D. M. Grant, A. Cruden, and J. R.McDonald, “Grid connected inverter suitable for economic residential fuel cell operation,” in Proc. Eur. Conf. Power Electron. Appl., Sep. 11-14, 2005, p. 10.

Simulation Analysis of SVPWM Inverter Fed Induction Motor Drives

Simulation Analysis of SVPWM Inverter Fed Induction Motor Drives

ABSTRACT

In this paper represent the simulation analysis of space vector pulse width modulated(SVPWM) inverter fed Induction motor drives. The main objective of this paper is analysis of Induction motor with SVPWM fed inverter and harmonic analysis of voltages & current. for control of IM number of Pulse width modulation (PWM) schemes are used to for variable voltage and frequency supply. The most commonly used PWM schemes for three-phase voltage source inverters (VSI) are sinusoidal PWM (SPWM) and space vector PWM (SVPWM). There is an increasing trend of using space vector PWM (SVPWM) because of it reduces harmonic content in voltage, Increase fundamental output voltage by 15% & smooth control of IM. So, here present Modeling & Simulation of SVPWM inverter fed Induction motor drive in MATLAB/SIMULINK software. The results of Total Harmonic Distortion (THD), Fast Fourier Transform (FFT) of current are obtained in MATLAB/Simulink software.

KEYWORDS

1. Inverter

2. VSI

3. SPWM

4. SVPWM

5. IM drive

SOFTWARE: MATALB/SIMULINK

BLOCK DIAGRAM:

Figure 1.Simulation Block Diag. of SVPWM Three level inverter with IM load

 CONCLUSION:

The SVPWM Inverter fed induction motor drive Modeling & then simulation is done in MATLAB/SIMULINK 12. From simulation results of THD & FFT analysis concluded that SVPWM technique is better over all PWM techniques which gives less THD in Inverter current 4.89%., which under the permissible limit.

REFERENCES:

 [1] A. R. Bakhshai H. R. Saligheh Rad G. Joos, space vector modulation based on classification method in three-phase multi-level voltage source inverters, IEEE 2001

[2] Bimal K Bose, modern power electronics and ac drives © 2002 Prentice hall ptr.

[3] Dorin O. Neacsu, space vector modulation –An introduction tutorial at IECON2001 IEEE 2001

[4] Fei Wang, Senior Member, “Sine-Triangle versus Space-Vector Modulation for Three-Level PWM Voltage-Source Inverters”, IEEE transactions on industry applications, vol. 38, no. 2, March/April 2002. The 27th Annual Conference of the IEEE Industrial Electronics Society

[5] F. Wang, Senior, Sine-Triangle vs. space vector modulation for three-level voltage source inverters ,IEEE 2000

Matrix Converters: A Technology Review

Matrix Converters: A Technology Review

ABSTRACT

The matrix converter is an array of controlled semiconductor switches that connects directly the three-phase source to the three-phase load. This converter has several attractive features that have been investigated in the last two decades. In the last few years, an increase in research work has been observed, bringing this topology closer to the industrial application. This paper presents the state-of-the-art view in the development of this converter, starting with a brief historical review. An important part of the paper is dedicated to a discussion of the most important modulation and control strategies developed recently. Special attention is given to present modern methods developed to solve the commutation problem. Some new arrays of power bidirectional switches integrated in a single module are also presented. Finally, this paper includes some practical issues related to the practical application of this technology, like overvoltage protection, use of filters, and ride-through capability.

KEYWORDS

1.     AC–AC power conversion

2.      Converters

3.     Matrix converters.

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

                        Fig. 1. Simplified circuit of a 3 x 3 matrix converter

CONCLUSION:

After two decades of research effort, several modulation and control methods have been developed for the matrix converter, allowing the generation of sinusoidal input and output currents, operating with unity power factor using standard processors. The most important practical implementation problem in the matrix converter circuit, the commutation problem between two controlled bidirectional switches, has been solved with the development of highly intelligent multistep commutation strategies. The solution to this problem has been made possible by using powerful digital devices that are now readily available in the market.

 REFERENCES:

[1] L. Gyugi and B. Pelly, Static Power Frequency Changers: Theory, Performance and Applications. New York: Wiley, 1976.

[2] A. Brandt, “Der Netztaktumrichter,” Bull. ASE, vol. 62, no. 15, pp. 714–727, July 1971.

[3] W. Popov, “Der Direktumrichter mit zyklischer Steuerung,” Elektrie, vol. 29, no. 7, pp. 372–376, 1975.

[4] E. Stacey, “An unrestricted frequency changer employing force commutated thyristors,” in Proc. IEEE PESC’76, 1976, pp. 165–173.

[5] V. Jones and B. Bose, “A frequency step-up cycloconverter using power transistors in inverse-series mode,” Int. J. Electron., vol. 41, no. 6, pp. 573–587, 1976.