Investigation on cascade multilevel inverter with symmetric, asymmetric, hybrid and multi-cell configurations

ABSTRACT:  

In recent past, numerous multilevel architectures came into existence but in this background, cascaded multilevel invert er (CM LI) is the promising structure. This type of multilevel invert er s synthesizes a medium voltage output based on a series connection of power cells which use standard low-voltage component configurations. This characteristic allows one to achieve high-quality output voltage and current wave forms, however, when the number of levels increases switching components and the count of dc sources are also increased.

This issue became a key motivation for the present paper which is devoted to investigate different types of CM LI using less number of switching components and dc sources thus finally proposed a new version of Multi-cell based CM LI. In order to verify the proposed topology, MAT LAB – simulations and hardware verification are carried out and results are presented.

KEYWORDS:
  1. Cascade multilevel invert er
  2. Multi-cell
  3. Switching components
  4. High quality output voltages

 SOFTWARE: MAT LAB/SIM U LINK

 INVESTIGATION ON CASCADE MULTILEVEL INVERT ER:

Figure 1 (a) CH B multilevel invert er, (b) key waveform for seven-level invert er, (c) CH B multilevel invert er by employing single-phase transformers, (d) simulation verification of seven-level CH B multilevel invert er, (e) F  FT spectrum.

 

Figure 2 (a) Asymmetrical thirteen-level CH B invert er, (b) simulation verification of thirteen-level CH B multilevel invert er, (c) FF T spectrum.

 

Figure 3 (a) Asymmetrical CH B multilevel invert er, (b) output voltages of each H-bridge module, (c) twenty-seven level output voltage waveform, (d) F FT spectrum.

 

Figure 4 (a) Asymmetrical CH B multilevel invert er using sub-cells, (b) output voltage of sub-cells, (c) thirty-one level output voltage waveform, (d) FF T spectrum.

 

Figure 5 (a) Hybrid CH B multilevel invert er, (b) output voltage of each H-bridge and load voltage (nine-level) waveform, (c) FF T spectrum.

Figure 6 (a) Hybrid multilevel invert er using traditional invert er, (b) output voltage waveform, (c) FF T Spectrum.

 

Figure 7 The proposed multi-cell CM LI.

.Figure 8 (a) The proposed 25-level asymmetric multi-cell CM LI, (b) key wave forms.

Figure 9 (a) Output voltage of first H-bridge, (b) output voltage of second H-bridge, (c) resultant output voltage with 25-levels, (d) FF T spectrum.

 CONCLUSION:

 In this paper CM LI with sub-cells is proposed with less number of switches. To highlight the merits of proposed invert er, an in-depth investigation is carried out on symmetric, asymmetric and hybrid multilevel invert er s based on CH B top o log i es. Symmetric configuration has capacity to produce only limited number of levels in output voltage, On the counter side, symmetrical configuration can be operated in asymmetrical mode with different DC sources. However, asymmetrical configurations can produce higher number of output levels and thereby qualitative output wave forms could be generated.

Later,

hybrid CH B invert er s are also introduced, which utilizes single DC source for entire structure. Thus complexity and voltage balancing issues can be reduced. Finally proposed invert er is introduced with less number of switching components and able to produce qualitative output wave forms. To verify the proposed invert er adequate simulation is done with help of MAT LAB/sim u link. Later on, hardware variations are carried out in laboratory. Verification are quite impressive with greater number of levels in the output voltage and lower harmonic content in FF T spectrum s. Spectrum s indicate that, low order harmonics are drastically reduced. Thus power quality is significantly enhanced. Thus proposed invert er shows some promising attributes when compared with traditional CH B based architectures.

References

] B ab a e  E, Ali l u S, La a l i S. A new general topology for cascaded
multilevel invert er s with reduced number of components based on
developed H-bridge. IEEE Trans Ind Electron 2014;61(8):3932–9.
[2] Malinowski Mar i us z, Go p a k u mar K, Rodriguez Jose, P e´re z
Marcelo A. A survey on cascaded multilevel invert er s. IEEE
Trans Ind Electron 2010;57(7):2197–205.
[3] Wu J C, Wu K D, Jo u H L, Xi a o ST. Diode-clamped multi-level
power converter with a zero-sequence current loop for three-phase
three-wire hybrid power filter. Elsevier J Elect r Power S y  s t Res
2011;81(2):263–70.
[4] K ho u c ha Far id, Lag o  n M o u n a So um i a, K he l o i Ab d e l a z i z,
Ben b o u z d Mohamed E l Ha ch e mi. A comparison of symmetrical
and asymmetrical three-phase H-bridge multilevel invert-er for
DTC induction motor drives. IEEE Trans Energy Converse
2011;26(1):64–72.
[5] E bra him i J, Ba b a e i E, G h a r e h p e ti an GB. A new topology of
cascaded multilevel converters with reduced number of components for high-voltage applications. IEEE Trans Power Electron
2011;26(11):3119–30

Analysis and Implementation of a Novel Bidirectional DC–DC Converter

ABSTRACT:  

A novel bidirectional dc–dc converter is presented in this paper and its circuit configuration of the proposed converter is very simple. The proposed converter employs a coupled induct-or with same winding turns in the primary and secondary sides. In step-up mode, the primary and secondary winding s of the coupled induct-or are operated in parallel charge and series discharge to achieve high step-up voltage gain. In step-down mode, the primary and secondary winding s of the coupled induct-or are operated in series charge and parallel discharge to achieve high step-down voltage gain.

Proposed converter

Thus, the proposed converter has higher step-up and step-down voltage gains than the conventional bidirectional dc–dc boost/buck converter. Under same electric specifications for the proposed converter and the conventional bidirectional boost/buck converter, the average value of the switch current in the proposed converter is less than the conventional bidirectional boost/buck converter. The operating principle and steady-state analysis are discussed in detail. Finally, a 14/42-V prototype circuit is implemented to verify the performance for the automobile dual-battery system.

KEYWORDS:
  1. Bidirectional dc–dc converter
  2. Coupled induct-or
 SOFTWARE: MAT LAB/SIMULATION
 CIRCUIT DIAGRAM:

 

Fig. 1. Proposed bidirectional dc–dc converter.

 EXPECTED SIMULATION RESULTS:

 

 Fig. 2. Some experimental wave-forms of the proposed converter in step-up mode. (a) iL1, iL2, and iL, (b) iS1, iS2, and iS3. (c) vDS1, vDS2, and vDS3.

 

 Fig. 3. Dynamic response of the proposed converter in step-up mode for the output power variation between 20 and 200 W.

Fig. 4. Some experimental wave-forms of the proposed converter in step down mode. (a) iLL, iL1, and iL2, (b) iS3, iS1, and iS2. (c) vDS3, vDS1, and vDS2.

Fig. 5. Dynamic response of the proposed converter in step-down mode for the output power variation between 20 and 200 W.

CONCLUSION:

 This paper researches a novel bidirectional dc–dc converter. The circuit configuration of the proposed converter is very simple. The proposed converter has higher step-up and step-down voltage gains and lower average value of the switch current than the conventional bidirectional boost/buck converter. From the experimental results, it is see that the experimental wave-forms agree with the operating principle and steady-state analysis. At full-load condition, the measured efficiency is 92.7% in step-up mode and is 93.7% in step-down mode. Also, the measured efficiency is around 92.7%–96.2% in step-up mode and is around 93.7%–96.7% in step-down mode, which are higher than the conventional bidirectional boost/buck converter.

REFERENCES:

[1] M. B. Cam a r a, H. G u a lo us, F. Gust in, A. Berth on, and B. D a k yo, “DC/DC converter design for super capacitor and battery power management in hybrid vehicle applications—Polynomial control strategy,” IEEE Trans. Ind. Electron., vol. 57, no. 2, pp. 587–597, Feb. 2010.

[2] T. B h at t a char ya, V. S. G i r i, K. Mathew, and L. U man and, “Multi phase bidirectional fly back converter topology for hybrid electric vehicles,” IEEE Trans. Ind. Electron., vol. 56, no. 1, pp. 78–84, Jan. 2009.

[3] Z. Am j ad i and S. S. Williamson, “A novel control technique for a switched-capacitor-converter-based hybrid electric vehicle energy storage system,” IEEE Trans. Ind. Electron., vol. 57, no. 3, pp. 926–934, Mar. 2010.

[4] F. Z. Pen g, F. Zhang, and Z. Q i an, “A magnetic-less dc–dc converter for dual-voltage automotive systems,” IEEE Trans. Ind. App l., vol. 39, no. 2, pp. 511–518, Mar./Apr. 2003.

[5] A. Na sir i, Z. N i e, S. B. Be k i a r o v, and A. E mad i, “An on-line UPS system with power factor correction and electric isolation using BI F RED converter,” IEEE Trans. Ind. Electron., vol. 55, no. 2, pp. 722–730, Feb. 2008.

Dynamic Modeling, Design, and Simulation of a Combined PEM Fuel Cell and Ultracapacitor System for Stand-Alone Residential Applications

ABSTRACT:  

The available power generated from a fuel cell (F C) power plant may not be sufficient to meet sustained load demands, especially during peak demand or transient events encountered in stationary power plant applications. An ultracapacitor (U C) bank can supply a large burst of power, but it cannot store a significant amount of energy. The combined use of F C and U C has the potential for better energy efficiency, reducing the cost of F C technology, and improved fuel usage. In this paper, we present an F C that operates in parallel with a U C bank. A new dynamic model and design methodology for an F C- and U C based energy source for stand-alone residential applications has been developed. Simulation results are presented using MAT LAB, Simulation, and Sim Power Systems environments based on the mathematical and dynamic electrical models developed for the proposed system.

KEYWORDS:
  1. Combined system
  2. Dynamic modeling
  3. Fuel cell (F C)
  4. Proton exchange membrane fuel cell (PE M F C)
  5. Ultracapacitor (U C)
 SOFTWARE: MAT LAB/SIM U LINK
BLOCK DIAGRAM:

     Fig. 1. Combination of F C system and U C bank.

                Fig. 2. PCU and load connection diagram.

EXPECTED SIMULATION RESULTS:

 

Fig. 3. Real power of residential load.

Fig. 4. Variation of FC system output voltage according to load demand.

 Fig. 5. Variation of UC bank terminal voltage according to load demand.

 

Fig. 6. Variation of UC bank charging and discharging current according to load switching.

Fig. 7. Variation of ac output power.

 

 Fig. 8. Variation of ac load voltage.

 

Fig. 9. Variation of modulation index corresponding to load demand.

 

Fig. 10. Variation of ac voltage phase angle.

Fig. 11. Variation of FC system dc output power.

Fig. 12. Variation of hydrogen flow rate.

CONCLUSION:

 A UC-based storage system is designed for a PEMFC operated grid independent home to supply the extra power required during peak demand periods. The parallel combination of the FC system and UC bank exhibits good performance for the stand-alone residential applications during the steady-state, load-switching, and peak power demand. Without the UC bank, the FC system must supply this extra power, thereby increasing the size and cost of the FC system.

Results

The results corresponding to high peak load demand during short time periods are not shown in order to simulate more realistic load profile. The load profile was created by measuring data at 15-s sampling interval. However, the proposed model can be used for different load profiles consisting of different transients and short-time interruption. Also, it can be extended for use in many areas such as portable devices, heavy vehicles, and aerospace applications. The lifetime of an FC system can be increased if combined FC system and UC bank is used instead of a stand-alone FC system or a hybrid FC and standby battery system.

REFERENCES:

[1] L. Gao, Z. Jiang, and R. A. Dougal, “An actively controlled fuel cell/battery hybrid to meet pulsed power demands,” J. Power Sources, vol. 130, no. 1–2, pp. 202–207, May 2004.

[2] T. S. Key, H. E. Sitzlar, and T. D. Geist, “Fast response, load-matching hybrid fuel cell,” Final Tech. Prog. Rep., EPRI PEAC Corp., Knoxville,TN NREL/SR-560-32743, Jun. 2003.

[3] S. Buller, E. Karden, D. Kok, and R. W. De Doncker, “Modeling the dynamic behavior of supercapacitors using impedance spectroscopy,” IEEE Trans. Ind. Appl., vol. 38, no. 6, pp. 1622–1626, Nov. 2002.

[4] J. L. Duran-Gomez, P. N. Enjeti, and A. Von Jouanne, “An approach to achieve ride-through of an adjustable-speed drive with flyback converter modules powered by super capacitors,” IEEE Trans. Ind. Appl., vol. 38, no. 2, pp. 514–522, Mar.–Apr. 2002.

[5] A. Burke, “Ultracapacitors: Why, how, and where is the technology,” J. Power Sources, vol. 91, no. 1, pp. 37–50, Nov. 2000.

Analysis of Active and Reactive Power Control of a Stand-Alone PEM Fuel Cell Power Plant

ABSTRACT:

This paper presents analytical details of how active and reactive power output of a stand-alone proton-exchange-membrane (PE M) fuel cell power plant (F C PP) is controlled. This analysis is based on an integrated dynamic model of the entire power plant including the reformer. The validity of the analysis is verified when the model is used to predict the response of the power plant to: 1) computer-simulated step changes in the load active and reactive power demand and 2) actual active and reactive load profile of a single family residence. The response curves indicate the load-following characteristics of the model and the predicted changes in the analytical parameters predicated by the analysis.

 

KEYWORDS:

  1. Active power control
  2. Fuel cell
  3. Fuel cell model,
  4. PEM fuel cell
  5. Proton exchange membrane (PEM)
  6. Reactive power.

 

BLOCK DIAGRAM:

Fig. 1. FCPP, inverter and load connection diagram.

 

EXPECTED SIMULATION RESULTS:

Fig. 2 Load step changes.

Fig. 3. FCPP output current.

Fig. 4. AC output voltage.

Fig. 5. Active output power.

Fig. 6. Reactive output power.

Fig.7 Output voltage phase angle.

Fig. 8. Hydrogen flow rate.

Fig. 9. AC output power.

Fig. 10. Active power of residential load.

Fig. 11. Reactive power of residential load.

Fig. 12 FCPP active power output.

Fig. 13. FCPP reactive power output.

                                                                                                                     CONCLUSION:

This paper introduces an integrated dynamic model for a fuel cell power plant. The proposed dynamic model includes a fuel cell model, a gas reformer model, and a power conditioning unit block. The model introduces a scenario to control active and reactive power output from the fuel cell power plant. The analysis is based on traditional methods used for the control of active and reactive power output of a synchronous generator. To test the proposed model, its active and reactive power outputs are compared with variations in load demand of a single family residence. The results obtained show a fast response of the fuel cell power plant to load changes and the effectiveness of the proposed control technique for active and reactive power output.

 

REFERENCES:

[1] M. A. Laughton, “Fuel cells,” Power Eng. J., vol. 16, no. 1, pp. 37–47, Feb. 2002.

[2] S. Um et al., “Computational fluid dynamics modeling of proton exchange membrane fuel cell,” J. Power Electrochem. Soc., vol. 147, no. 12, pp. 4485–4493, 2000.

[3] D. Singh et al., “A two-dimension analysis of mass transport in proton exchange membrane fuel cells,” Int. J. Eng. Sci., vol. 37, pp. 431–452, 1999.

[4] J. C. Amphlett et al., “A model predicting transient response of proton exchange membrane fuel cells,” J. Power Sources, vol. 61, pp. 183–188, 1996.

[5] J. Padulles et al., “An integrated SOFC plant dynamic model for power systems simulation,” J. Power Sources, vol. 86, pp. 495–500, 2000.

Control of Induction Motor Drive using Space Vector PWM

ABSTRACT:  

In this paper speed of acceptance engine is controlled, supply from three stage connect transformer because the variety in information Voltage or recurrence in turn both changes the speed of an taking in engine. Variable voltage and recurrence for Adjustable Speed Drives (AS D) is constantly acquires from a three-stage Voltage Source Invert er (V SI) also P WM strategies controls the Voltage and recurrence of transform er, so which is an imperative viewpoint in the use of AS D s.

P WM Techniques

A number of P WM techniques are there to obtain variable voltage and frequency supply such as P WM, SP WM, S VP WM and among the various modulation strategies, SVPWM is one of the most efficient techniques as it has better performance and output voltage is similar to sinusoidal. SVPWM the modulation index in linear region will also be high when compared to other.

 BLOCK DIAGRAM:

 Figure 1: AS D Block Diagram

 EXPECTED SIMULATION RESULTS:

 Figure 2: SP WM Pulses

Figure 3: Invert er o/p line voltages

Figure 4: Motor Speed and Electromagnetic torque.

Figure 5: SVPWM output gate pulses

                  Figure 6:Open Loop Drive Speed response with TL=0

Figure 7: Open Loop Drive Speed response with different TL

Figure 8: Sinusoidal PWM based open loop drive Load Current T H D

 CONCLUSION:

MAT LAB/Sim u link is used to carryout the simulation of “Control of Induction Motor Drive Using Space Vector P WM” for open loop as well as closed control by which the appropriate output results are obtained. The variation of speed of Induction Motor is observed by varying the load torque in open loop control and the table gives the results. Also observed that for the change in input speed commands the motor speed is settled down to its final value within 0.1 sec in closed loop model.

REFERENCES:

[1] Ab d e l fat ah K o l l i, Student Member, IEEE, Olivier Be t ho u x, Member, IEEE, A l e x a n d re D e Be r n a  r d in i s, Member, IEEE, Eric Lab our e, and G e r a rd Co q u e r y “Space-Vector P WM Control Synthesis for an H-Bridge Drive in Electric Vehicles” IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 62, NO. 6, JULY 2013. pp. 2241-2252.

[2]Mr. Sand e e p N Pan ch a l, Mr. Vi s h a l S She t h, Mr. A k s hay A P and ya “Simulation Analysis of S V P WM Invert er Fed Induction Motor Drives” International Journal of Emerging Trends in Electrical and Electronics (IJET E  E) Vol. 2, Issue. 4, April-2013. pp. 18-22 .

[3]H a o ran S hi, Wei X  u, Chen  g h u a F u and Y a o Yang. “Research on Three phase Voltage Type P  WM Rectifier System Based on S V P WM Control” Research Journal of Applied Sciences, Engineering and Technology 5(12): 3364-3371, 2013. pp. 3364-3371.

A Novel Multilevel Inverter Based on Switched DC Sources

ABSTRACT:  

This paper presents a multilevel invert er that has been conceptualized to reduce component count, particularly for a large number of output levels. It comprises floating input dc sources alternately connected in opposite polarities with one another through power switches whereas each input dc level appears in the stepped load voltage either individually or in additive combinations with other input levels. This approach results in reduced number of power switches as compared to classical to p o log i e s. A single-phase five-level invert er demonstrates the working principle of the proposed topology. The simulation investigates the topology and an exhaustive comparison of the proposed topology is made against the classical cascaded H-bridge topology.

 SOFTWARE: MAT LAB/SIM U LINK

 CIRCUIT DIAGRAM:

 

Fig. 1. Single-phase invert er based on the proposed topology with two input sources.

 EXPECTED SIMULATION RESULTS:

 

 Fig. 2. (a) Reference and carrier wave forms for the proposed scheme for a five-level output. (b) Aggregated signal “a(t).”

Fig. 3. Switching pulse pattern for the five-level invert er.

Fig. 4. Simulation results. (a) Five-level voltage output. (b) Harmonic spectrum of the load voltage.

Fig. 5. Simulation results. (a) Load current waveform with an R L load (R =

2 Ω and L = 2 m H). (b) Harmonic spectrum of the load current.

 

CONCLUSION:

As M LI s are gaining interest, efforts are being directed toward reducing the device count for increased number of output levels, therefore A novel topology for M LI s has been proposed in this paper to reduce the device count. The working principle of the proposed topology has been explained, and mathematical formulations corresponding to output voltage, source currents, voltage stresses on switches, and power losses have been developed. Simulation studies performed on a five-level invert er based on the proposed structure have been validated experimentally.

Comparison

Comparison of the proposed topology with conventional top o l o g i es reveals that the proposed topology significantly reduces the number of power switches and associated gate driver circuits. Analytical comparisons on the basis of losses and switch cost indicate that the proposed topology is highly competitive. The proposed topology can be effectively employed for applications where isolated dc sources are available. The advantage of the reduction in the device count, however, imposes two limitations: 1) requirement of isolated dc sources as is the case with the C H B topology and 2) curtailed modular it y  and fault-tolerant capabilities as compared to the C H B topology.

REFERENCES

[1]S. K o u r o, M. Malinowski, K. Go pa k u m a r, J. P o u, L. Fran q u e lo, B. Wu, J. Rodriguez, M. Perez, and J. Leon, “Recent advances and industrial
applications of multilevel converters,” IEEE Trans. Ind. Electron., vol. 57,
no. 8, pp. 2553–2580, Aug. 2010.
[2] G. But i c chi, E. Loren z an i, and G. France s chin i, “A five-level single-phase
grid-connected converter for renewable distributed systems,” IEEE Trans.
Ind. Electron., vol. 60, no. 3, pp. 906–918, Mar. 2013.

[3] J. Rodriguez, J.-S. La i, and F. Z h en g Peng, “Multilevel invert er s: A survey
of top o log i es, controls, applications,” IEEE Trans. Ind. Electron., vol. 49,
no. 4, pp. 724–738, Aug. 2002.
[4] S. De, D. Banerjee, K. Siva Kumar, K. Gopakumar, R. Ramchand, and
C. Patel, “Multilevel inverters for low-power application,” IET Power
Electronics, vol. 4, no. 4, pp. 384–392, Apr. 2011.
[5] M. Malinowski, K. Gopakumar, J. Rodriguez, and M. A. Pérez, “A survey
on cascaded multilevel inverters,” IEEE Trans. Ind. Electron., vol. 57,
no. 7, pp. 2197–2206, Jul. 2010

Electric Spring for Voltage and Power Stability and Power Factor Correction

ABSTRACT:  

Electric Spring (ES), a new smart grid technology, has earlier been used for providing voltage and power stability in a weakly regulated/stand-alone renewable energy source powered grid. It has been proposed as a demand side management technique to provide voltage and power regulation. In this paper, a new control scheme is presented for the implementation of the
electric spring, in conjunction with non-critical building loads like electric heaters, refrigerators and central air conditioning system. This control scheme would be able to provide power factor correction of the system, voltage support, and power balance for the critical loads, such as the building’s security system, in addition to the existing characteristics of electric spring of voltage and power stability. The proposed control scheme is compared with original ES’s control scheme where only reactive-power is injected. The improvised control scheme opens new avenues for the utilization of the electric spring to a greater extent by providing voltage and power stability and enhancing the power quality in the renewable energy powered microgrids

 BLOCK DIAGRAM:

Fig. 1. Electric Spring in a circuit

EXPECTED SIMULATION RESULTS:

Fig. 2. Over-voltage, Conventional ES: Power Factor of system (ES turned on at t = 0.5 sec)

Fig. 3. Over-voltage, Conventional ES: Active and Reactive power across critical load, non-critical load, and electric spring (ES turned on at t=0.5 sec)

Fig. 4 Under-voltage, Conventional ES: RMS Line voltage, ES Voltage, and Non-Critical load voltage (ES turned on at t=0.5 sec)

Fig. 5. Under-voltage, Conventional ES: Power Factor of system (ES turned on at t = 0.5 sec)

Fig. 6. Under-voltage, Conventional ES: Active and Reactive power across critical load, non-critical load, and electric spring (ES turned on at t=0.5 sec)

Fig. 7. Over-voltage, Improvised ES: RMS Line voltage, ES Voltage, and Non-Critical load voltage (ES turned on at t=0.5 sec)

Fig. 8. Over-voltage, Improvised ES: Power Factor of system (ES turned on at t = 0.5 sec)

CONCLUSION

In this paper as well as earlier literature s, the Electric Spring
was demonstrated as an ingenious solution to the problem of
voltage and power instability associated with renewable energy
powered grids. Further in this paper, by the implementation of
the proposed improvised control scheme it was demonstrated
that the improvised Electric Spring (a) maintained line voltage
to reference voltage of 230 Volt, (b) maintained constant
power to the critical load and (c) improved overall power
factor of the system compared to the conventional ES. Also,
the proposed ‘input-voltage-input-current’ control scheme is
compared to the conventional ‘input-voltage’ control. It was
shown, through simulation and hardware-in-loop emulation,
that using a single device voltage and power regulation and
power quality improvement can be achieved.

Control Scheme

It was also shown that the improvised control scheme has merit over the conventional ES with only reactive power injection.
Also, it is proposed that electric spring could be embedded
in future home appliances. If many non-critical loads in the
buildings are equipped with ES, they could provide a reliable
and effective solution to voltage and power stability and in sit u
power factor correction in a renewable energy powered
micro-grids. It would be a unique demand side management
(D S M) solution which could be implemented without any
reliance on information and communication technologies.

REFERENCES

[1] S. Y. Hui, C. K. Lee, and F. F. Wu, “Electric springs – a new smart
grid technology,” IEEE Transactions on Smart Grid, vol. 3, no. 3, pp.
1552–1561, Sept 2012.
[2] S. Hui, C. Lee, and F. WU, “Power control circuit and
method for stabilizing a power supply,” 2012. [Online]. Available:
http://www.google.com/patents/US20120080420
[3] C. K. Lee, N. R. Ch a u d h u r i, B. Ch a u d h u r i, and S. Y. R. Hui, “Droop
control of distributed electric springs for stabilizing future power grid,”
IEEE Transactions on Smart Grid, vol. 4, no. 3, pp. 1558–1566, Sept
2013.
[4] C. K. Lee, B. Ch a u d h u r i, and S. Y. Hui, “Hardware and control
implementation of electric springs for stabilizing future smart grid with
intermittent renewable energy sources,” IEEE Journal of Emerging and
Selected Topics in Power Electronics, vol. 1, no. 1, pp. 18–27, March
2013.
[5] C. K. Lee, K. L. Che n g, and W. M. N g, “Load characterization of electric
spring,” in 2013 IEEE Energy Conversion Congress and Exposition, Sept
2013, pp. 4665–4670.

Control of a Three-Phase Hybrid Converter for a PV Charging Station

ABSTRACT:  

Hybrid Boost converter (H BC) has been proposed to supplant a dc/dc support converter and a dc/air conditioning converter to decrease transformation stages and exchanging misfortune. In this paper, control of a three-stage H BC in a P V charging station is structured and tried. This H BC interfaces a P V framework, a dc framework with a hybrid plugin electrical vehicles (HP E V s) and a three-stage air conditioning network. The control of the H BC is intended to acknowledge most maximum power point tracking (MP PT) for P V, dc transport voltage direction, and air conditioning voltage or receptive power control. A proving ground with power hardware exchanging subtleties is worked in MAT LAB/Sim Power systems for approval. Reproduction results show the possibility of the structured control design. At last, lab exploratory testing is directed to show H BC’s control execution.

 BLOCK DIAGRAM:

Fig. 1. Topology of the three-phase H BC-based P V charging station.

EXPECTED SIMULATION RESULTS:

 

 Fig. 2. Performance of a modified I C-PI MP PT algorithm when solar

irradiance variation is applied.

Fig. 3. Performance of the dc voltage control in the vector control. The solid lines represent the system responses when the dc voltage control is enabled. The dashed lines represent the system responses when the dc voltage control is disabled.

Fig. 4. Performance of a proposed vector control to supply or absorb reactive power independently.

Fig. 5. Power management of P V charging station.

Fig. 6. D st, Md and M q for case 4.

Fig. 7. System performance under 70% grid’s voltage drop.

 CONCLUSION:

Control of three-stage H BC in a P  V charging station is proposed in this paper. The three-stage H BC can spare exchanging misfortune by joining a dc/dc sponsor and a dc/air conditioning converter into a solitary converter structure. Another control for the three-stage H BC is intended to accomplish MP PT, dc voltage direction and responsive power following. The MPPT control uses altered gradual conductance-PI based MPPT strategy. The dc voltage direction and responsive power following are acknowledged utilizing vector control.

Five contextual investigations are led in PC reenactment to exhibit the execution of MPPT, dc voltage controller, responsive power following and in general power the board of the PV charging station. Trial results check the task of the PHEV charging station utilizing HBC topology. The reproduction and trial results show the adequacy and vigor of the proposed control for PV charging station to keep up nonstop dc control supply utilizing both PV power and air conditioning framework control.

REFERENCES

[1]A. Khaligh and S. Dusmez, “Comprehensive topological analysis of conductive
and inductive charging solutions for plug-in electric vehicles,”
IEEE Transactions on Vehicular Technology, vol. 61, no. 8, pp. 3475–
3489, 2012.
[2] T. Anegawa, “Development of quick charging system for electric vehicle,”
Tokyo Electric Power Company, 2010.
[3] F. Musavi, M. Edington, W. Eberle, and W. G. Dunford, “Evaluation
and efficiency comparison of front end ac-dc plug-in hybrid charger
topologies,” IEEE Transactions on Smart grid, vol. 3, no. 1, pp. 413–
421, 2012.
[4] M. Yilmaz and P. T. Krein, “Review of battery charger topologies,
charging power levels, and infrastructure for plug-in electric and hybrid
vehicles,” IEEE Transactions on Power Electronics, vol. 28, no. 5, pp.
2151–2169, May 2013.
[5] G. Gamboa, C. Hamilton, R. Kerley, S. Elmes, A. Arias, J. Shen, and
I. Batarseh, “Control strategy of a multi-port, grid connected, direct-dc
pv charging station for plug-in electric vehicles,” in Energy Conversion
Congress and Exposition (ECCE), 2010 IEEE. IEEE, 2010, pp. 1173–
1177.

Design of an Efficient Dynamic Voltage Restorer for Compensating Voltage Sags, Swells, and Phase Jumps

ABSTRACT:  

This paper presents a novel design of a dynamic voltage restorer (DVR) which mitigate voltage sags, swell and phase jumps by injecting minimum active power in system and provides the constant power at load side without any disturbance. The design of this compensating device presented here includes the combination of P WM-based control scheme, d q 0 transformation and PI controller in control part of its circuitry, which enables it to minimize the power rating and to response promptly to voltage quality problems faced by today’s electrical power industries.

An

immense knowledge of power electronics was applied in order to design and model of a complete test system solely for analyzing and studying the response of this efficient DVR. In order to realize this control scheme of DVR MAT LAB/SIM U LINK atmosphere was used. The results of proposed design of DVR’s control scheme are compared with the results of existing classical DVR which clearly demonstrate the successful compensation of voltage quality problems by injecting minimum active power.

BLOCK DIAGRAM:

 

 Fig.1. Block Diagram of DVR

 EXPECTED SIMULATION RESULTS:

 

Fig.2.Source Voltage with Sag of 0.5 p.u.

Fig.3.Load Voltage after Compensation through proposed DVR

Fig.4. Load Voltage after Compensation through classical DVR

Fig.5. Voltage injected by proposed DVR as response of Sag

Fig.6.Source Voltage with Swell of 1.5 p.u.

Fig.7. Load Voltage after compensation through proposed DVR

Fig.8. Load Voltage after Compensation through classical DVR

Fig.9. Voltage injected by DVR as response of Swell

Fig.10. .Load Voltage after Compensation of Phase jump

Fig.11. d q 0 form of difference voltage obtained by proposed DVR

Fig.12. d q 0 form of difference voltage obtained by classical DVR

CONCLUSION:

As the world is moving towards modernization, the most essential need that it has is of an efficient and reliable power of excellent quality. Nowadays, more and more sophisticated devices are being introduced, and their sensitivity is  dependent upon the quality of input power. Because even a slight disturbance in power quality, such as Voltage sags, voltage swells, and harmonics, which lasts in tens of milliseconds, can result in a huge loss because of the failure of end use equipment s. For catering such voltage quality problems an efficient DVR is proposed in this paper with the capability of mitigating voltage sags, swells, and phase jumps by injecting minimum active power hence decreasing the VA rating of DVR.

REFERENCES

[1] K u m  a r, R. A nil, G. Siva K u mar, B. K a l y an K u mar, and Ma he sh K. Mi s h  R a. “Compensation of voltage sags and harmonics with phase jumps through DVR with minimum VA rating using Particle Swarm Optimization.” In Nature & Biologically Inspired Computing, 2009. NaBIC 2009. World Congress on, pp. 1361-1366. IEEE, 2009.
[2] Song song, Chen, Wang Jian wei, Ga o Wei, and Hu Xiaoguang. “Research and design of dynamic voltage restorer.” In Industrial Informatics (INDIN), 2012 10th IEEE International Conference on, pp. 408-412. IEEE, 2012.
[3] A. Bendre, D. Divan, W. Kranz, and W. E. Brumsickle, “Are Voltage Sags Destroying Equipment?,” IEEE Industry Applications Magazine, vol. 12, pp. 12-21, July-August 2006.

 

An Enhanced Voltage Sag Compensation Scheme for Dynamic Voltage Restorer

ABSTRACT:  

This paper deals with improving the voltage quality of sensitive loads from voltage sags using dynamic voltage restorer (DVR). The higher active power requirement associated with voltage phase jump compensation has caused a substantial rise in size and cost of dc link energy storage system of DVR. The existing control strategies either mitigate the phase jump or improve the utilization of dc link energy by (i) reducing the amplitude of injected voltage, or (ii) optimizing the dc bus energy support.

IN

this paper, an enhanced sag compensation strategy is proposed that mitigates the phase jump in the load voltage while improving the overall sag compensation time. An analytical study shows that the proposed method significantly increases the DVR sag support time (more than 50%) compared with the existing phase jump compensation methods. This enhancement can also be seen as a considerable reduction in dc link capacitor size for new installation. The performance of proposed method is evaluated using simulation study and finally, verified experimentally on a scaled lab prototype.

CIRCUIT DIAGRAM:

 

 Fig. 1 Basic DVR based system configuration.

 EXPECTED SIMULATION RESULTS:

 

Fig. 2. Simulation results for the proposed sag compensation method for 50% sag depth. (a) PC C voltage, (b) load voltage, (c) DVR voltage, (d) DVR active and reactive power, and (e) dc link voltage.

Fig. 3. Simulation results for the proposed sag compensation method for 23% sag depth. (a) PC C voltage, (b) load voltage, (c) DVR voltage, (d) DVR active and reactive power, and (e) dc link voltage.

 CONCLUSION:

This paper proposed an enhanced sag compensation scheme for capacitor supported DVR. The proposed strategy improves the voltage quality of sensitive loads by protecting them against the grid voltage sags involving the phase jump. It also increases compensation time by operating in minimum active power mode through a controlled transition once the phase jump is compensated. To illustrate the effectiveness of the proposed method an analytical comparison is carried out with the existing phase jump compensation schemes. It is shown that compensation time can be extended from 10 to 25 cycles (considering pr e sag injection as the reference method) for the designed limit of 50% sag depth with 450 phase jump. Further extension in compensation time can be achieved for intermediate sag depths.

MATLAB/SIMULINK

extended compensation time is seen as considerable reduction in dc link capacitor size (for the studied case more than 50%) for the new installation. MAT LAB/Sim u link software evaluated the effectiveness of the proposed method through extensive simulations and validated on a scaled lab prototype experimentally. The experimental results demonstrate the feasibility of the proposed phase jump compensation method for practical applications.

REFERENCES

[1] J.A. Martinez and J.M. Ar n ed o, “Voltage sag studies in distribution
networks- part I: System modeling,” IEEE Trans. Power Del., vol.
21,no. 3, pp. 338–345, Jul. 2006.
[2] J.G. Nielsen, F. Bl a ab j e r g and N. Mo h  an, “Control strategies for
dynamic voltage restorer, compensating voltage sags with phase jump,”
in Proc. IEEE AP EC, 2001, pp. 1267–1273.
[3] J.D. Li, S.S. Choi, and D.M. Vi l a t h g a m u w a, “Impact of voltage phase
jump on loads and its mitigation,” in Proc. 4th Int. Power Electron.
Motion Control Conf., Xian, China, Aug. 14–16, 2004, vol. 3, pp. 1762–
176.