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.

Modeling And Simulation For Voltage Sags/Swells Mitigation Using Dynamic Voltage Restorer (Dvr)

Modeling And Simulation For Voltage Sags/Swells Mitigation Using Dynamic Voltage Restorer (Dvr)

                                

ABSTRACT

This project describes the problem of voltage sags and swells and its severe impact on non linear loads or sensitive loads. The dynamic voltage restorer (DVR) has become popular as a cost effective solution for the protection of sensitive loads from voltage sags and swells. The control of the compensation voltages in DVR based on dqo algorithm is discussed. It first analyzes the power circuit of a DVR system in order to come up with appropriate control limitations and control targets for the compensation voltage control. The proposed control scheme is simple to design. Simulation results carried out by Matlab/Simulink verify the performance of the proposed method .

KEYWORDS

1.     DVR

2. Voltage sags
3. Voltage swells
4. Sensitive load

SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM

                                                    Figure 1: Schematic diagram of DVR

CONCLUSION:

The modeling and simulation of a DVR using MATLAB/SIMULINK has been presented. A control system based on dqo technique which is a scaled error of the between source side of the

DVR and its reference for sags/swell correction has been presented. The simulation shows that the DVR performance is satisfactory in mitigating voltage sags/swells.

REFERENCES:

[1] N.G. Hingorani, “Introducing Custom Power in IEEE Spectrum,” 32p, pp. 4l-48, 1995.

[2] IEEE Std. 1159 – 1995, “Recommended Practice for Monitoring Electric Power Quality”.

[3] P. Boonchiam and N. Mithulananthan, “Understanding of Dynamic Voltage Restorers through MATLAB Simulation,” Thammasat Int. J. Sc. Tech., Vol. 11, No. 3, July-Sept 2006.

[4] J. G. Nielsen, M. Newman, H. Nielsen,and F. Blaabjerg, “Control and testing of a dynamic voltage restorer (DVR) at medium voltage level,” IEEE Trans. Power Electron., vol. 19, no. 3,p.806, May 2004.

[5] A. Ghosh and G. Ledwich, “Power Quality Enhancement Using Custom Power Devices,” Kluwer Academic Publishers, 2002.

A Novel Control Method for Shunt Active Power Filters Using SVPWM

A Novel Control Method for Shunt Active Power Filters Using SVPWM

ABSTRACT

A novel control method for shunt active power filters using SVPWM is presented. In the proposed control method, The APF reference voltage vector is generated to instead of the reference current, and the desired APF output voltage is generated by space vector modulation. The control algorithm is simple and can be realized by a low cost controller. The active power filter based on the proposed method can eliminate harmonics, compensate reactive power and balance load asymmetry. A 10kVA laboratory prototype of APF is designed. This prototype adopts the voltage source inverter as the main power circuit and low cost DSP ADMC326 as control core. Simulation and experimental results proves the validity of the analysis and the feasibility of the APF with the proposed control method.

KEYWORDS

1.     Active power filter

2.     SVPWM

3.     DSP

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

 

Figure 1. Control block diagram of proposed active power filter

Figure 2.Configuration of an active power filter using a SVPWM

CONCLUSION:

In this paper, a novel simplified control method, which is suitable for digital control realization, for the active power filter using SVPWM is proposed. This method requires few sensors, and is simple in algorithm, fixed in switching frequency and able to compensate harmonics, reactive power and unbalance loads instantaneously. The performance of active power filters with this method in compensating harmonics is examined and proved to be excellent. The simple algorithm will be able to reduce the complexity of the control circuitry and cut the cost of the system.

REFERENCES:

[1] Singh.B, Al-Haddad.K, Chandra.A, “Review of active filters for power quality improvement”, IEEE Trans. Ind. Electron., (46), 5, Oct, 1999, pp. 960-971

[2] El-Habrouk. M, Darwish. M. K, Mehta. P, “Active power filters—A review,” Proc. IEE—Elect. Power Applicat., vol. 147, no. 5, Sept. 2000, pp. 403–413.

[3] Akagi, H., “New trends in active filters for power conditioning,” IEEE Trans. on Industry Applications, (32), 6, Nov-Dec, 1996, pp. 1312-1322

[4] Peng Fangzheng, “Application issues of active power filters,” IEEE Industry Applications Magazine, v 4, n 5, Sep-Oct, 1998, pp. 21-30

[5] Akagi.H, Kanazawa.Y, and Nabae.A, “Instantaneous reactive power compensators comprising switching device without energy storage components,” IEEE Trans. on Industry Applications, (20), 3, 1984, pp. 625-630.

A Versatile Control Scheme for a Dynamic Voltage Restorer for Power-Quality Improvement

ABSTRACT:

This paper presents a control system based on a repetitive controller to compensate for key power-quality disturbances, namely voltage sag, harmonic voltages, and voltage imbalances, using a dynamic voltage restorer (DVR). The control scheme deals with all three disturbances simultaneously within a bandwidth. The control structure is quite simple and yet very robust; it contains a feed forward term to improve the transient response and a feedback term to enable zero error in steady state. The well-developed graphical facilities available in PSCAD/EMTDC are used to carry out all modeling aspects of the repetitive controller and test system. Simulation results show that the control approach performs very effectively and yields excellent voltage regulation.

KEYWORDS:

1.      Dynamic voltage restorer (DVR)

2.      harmonic distortion

3.      power quality (PQ)

4.      repetitive control

5.      voltage sag

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Test system implemented in PSCAD/EMTDC.

CONCLUSION:

The use of dynamic voltage restorers in PQ-related applications is increasing. The most popular application has been on voltage sags amelioration but other voltage-squality phenomena may also benefit from its use, provided that more robust control schemes than the basic PI controller become available. A case in point is the so called repetitive controller proposed in this paper, which has a fast transient response and ensures zero error in steady state for any sinusoidal reference input and for any sinusoidal disturbance whose frequencies are an integer multiple of the fundamental frequency. To achieve this, the controller has been provided with a feed forward term and feedback term. The design has been carried out by studying the stability of the closed-loop system including possible modeling errors, resulting in a controller which possesses very good transient and steady-state performances for various kinds of disturbances.

A key feature of this control scheme is its simplicity; only one controller is required to eliminate three PQ disturbances, namely, voltage sags, harmonic voltages, and voltage imbalances. The controller can be implemented by using either a stationary reference frame or a rotating reference frame. In this paper, the highly developed graphical facilities available in PSCAD/EMTDC have been used very effectively to carry out all aspects of the system implementation. Comprehensive simulation results using a simple but realistic test system show that the repetitive controller and the DVR yield excellent voltage regulation, thus screening a sensitive load point from upstream PQ disturbances.

  

REFERENCES:

[1] M. H. J. Bollen, “What is power quality?,” Elect. Power Syst. Res., vol. 66, no. 1, pp. 5–14, July 2003.

[2] J. G. Nielsen and F. Blaabjerg, “A detailed comparison of system topologies for dynamic voltage restorers,” IEEE Trans. Ind. Appl., vol. 41, no. 5, pp. 1272–1280, Sep./Oct. 2005.

[3] V. K. Ramachandaramurthy, A. Arulampalam, C. Fitzer, C. Zhan, M. Barnes, and N. Jenkins, “Supervisory control of dynamic voltage restorers,” Proc. Inst. Elect. Eng., Gen., Transm. Distrib, vol. 151, no. 4, pp. 509–516, Jul. 2004.

[4] P. T. Nguyen and T. K. Saha, “Dynamic voltage restorer against balanced and unbalanced voltage sags: Modelling and simulation,” in Proc. IEEE Power Eng. Soc. General Meeting, Jun. 2004, vol. 1, pp. 639–644, IEEE.

[5] M. H. J. Bollen, Understanding Power Quality Problems: Voltage Sags and Interruptions.. Piscataway, NJ: IEEE Press, 2000.

Soft Computing Techniques for the Control of an Active Power Filter

ABSTRACT:

Non model-based controllers have been explored for the control of a shunt active power filter (APF) designed for harmonic and reactive current mitigation. In this paper, three soft computing techniques viz; fuzzy logic, neural network, and genetic algorithm are used to design alternative control schemes for switching the APF. The models for these control schemes are designed and simulated in MATLAB. A comparative study of the results obtained using these artificial-intelligence-based schemes is presented.

KEYWORDS:

1.      Active power filter (APF)

2.      fuzzy logic

3.      genetic algorithm (GA

4.      neural network

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig.1. Configuration of the APF.

CONCLUSION:

The overall aim of this paper was to consider methods of achieving better utilization and control of active power filters dealing with harmonic and reactive current compensation. Alternative schemes based on soft computing techniques have been proposed. Non model-based controllers designed around fuzzy logic, neural network, and genetic algorithms were applied to control the switching of the active power filter and were found to provide much better response under varying load and supply conditions.

REFERENCES:

[1] M. El-Habrouk, M. K. Darwish, and P. Mehta, “Active power filters: A review,” Proc. IEEE Electr. Power Appl., vol. 147, no. 5, pp. 403–412, Sep. 2000.

[2] B. Singh, K-Al-Haddad, and A. Chandra, “A review of active filters for power quality improvement,” IEEE Trans. Ind. Electron, vol. 46, no. 5, pp. 960–971, Oct. 1999.

[3] W. M. Grady,M. J. Sanotyj, and A. H. Noyola, “Survey of active power line conditioning methodologies,” IEEE Trans. Power Del., vol. 5, no. 3, pp. 1536–1542, Jul. 1990.

[4] H. L. Jou, J. C. Wu, and H. Y. Chu, “New single-phase active power filter,” Proc. Inst. Elect. Eng., Electr. Power Appl., vol. 141, no. 3, pp. 129–134, May 1994.

[5] K. Chaterjee, B. G. Fernandes, and G. K. Dubey, “An instantaneous reactive volt-ampere compensator and harmonic suppressor system,” IEEE Trans. Power Electron., vol. 14, no. 2, pp. 381–392, Mar. 1999.