New Approach for Harmonic Mitigation in Single Phase Five-Level CHBMI with Fundamental Frequency Switching

ABSTRACT:

The main objective of this paper is to study and analyse the voltage output waveform of a multilevel invert  er, to suggest a new approach for harmonic mitigation improving the converter performance. These last type of converters represent a new technology in the field of DC/AC electrical energy conversion, presenting advantages respect to the traditional converters. In fact, the multilevel power converters present a low harmonic content and a high voltage level. The paper considers a five-level single-phase cascaded H-bridge invert er  (CHBMI) and fundamental frequency modulation techniques. The voltage waveform analysis has allowed to identify a working area of the converter where there are lowest values of the considered harmonic amplitude. The simulated behavior of the model of the converter, with the logic piloting gate signals, has been obtained  in Mat  lab-Sim u link environment.

 KEYWORDS:

  1. Multilevel Power Converter
  2. Soft switching
  3. Phase Shifted Voltage Cancellation
  4. CHBMI

 SOFTWARE: MAT LAB/SIM U LINK

 CIRCUIT DIAGRAM:

Fig. 1. Single-phase five-level CHBMI

EXPECTED SIMULATION RESULTS:

 

Fig. 2. Gate signals H-Bridge I with a=~=30°.

Fig. 3. Gate Signals H-Bridge 2 with a=~=30°.

Fig. 4. Voltage trend over time with a=~=30°.

CONCLUSION:

In this paper a fundamental switching modulation strategy for single-phase five-level CHBMI that mitigate low order harmonics is presented. The proposed method, through the control of the a and P parameters, allows the mitigation of third, fifth, seventh, ninth and eleventh harmonics. The values of the control parameters can be obtained without needs to solve a set of nonlinear transcendental equations. However, the fundamental harmonic amplitude can only be varied from 42% to 92% of 2 (V o  c*4 Y r r).

REFERENCES:

[I] K. Siva k u  m  a r, A. D a s, R. Ram c  h  an d, C. Patel, and K. Go p a  k u mar, A five-level invert  er scheme for a four-pole induction motor drive by feeding the identical voltage-profile winding from both sides, IEEE Trans. Ind. Electron., vol. 57, no. 8,pp. 2776-2784, Aug. 2010.

[2] M. Caruso e t a!., Design and experimental characterization of a low-cost, real-time, wireless AC monitoring system based on AT mega 328 P-PU micro controller, 2015 A E IT International Annual Conference (A E IT), Naples, 2015, pp. 1-6. do i: 1 O. 1109/ a E IT. 2015.7415267

[3] M. Caruso, R. Mice l i, P. Romano, G. Sc h e t t in o, C. Spat a r o and F. Viola, A low-cost, real-time monitoring system for P V plants based on AT mega 328 P-PU micro controller, 2015 IEEE International Telecommunications Energy Conference (IN TEL E C), Osaka, 2015, pp. 1-5. do i: 10.1109/INTL EC 2015. 7572270

[4] M. Caruso, V. Ce c c on  i, A. O. Di Tom mas o, and R. Rocha. A Rotor Flux and Speed Observer for Sensor less Single-Phase Induction Motor Applications. International Journal of Rotating Machinery, vol. 2012, no. 276906, p. 13,2012.

[5] M. Caruso, A O. Di Tom mas o, F. G end u so, R. Mic e l i and G. R. Gall u  z z o, A D S P-Based Resolver-To-Digital Converter for High-Performance Electrical Drive Applications, in IEEE Transactions on Industrial Electronics, vol. 63, no. 7, pp. 4042- 4051, July 2016.

A ZVS Grid-Connected Three-Phase Inverter

ABSTRACT:

A six-switch three-phase inverter is widely used in a high-power grid-connected system. However, the anti parallel diodes in the topology operate in the hard-switching state under the traditional control method causing severe switch loss and high electromagnetic interference problems. In order to solve the problem, this paper proposes a topology of the traditional six-switch three-phase inverter but with an additional switch and gave a new space vector modulation (SVM) scheme. In this way, the inverter can realize zero-voltage switching (ZVS) operation in all switching devices and suppress the reverse recovery current in all anti parallel diodes very well. And all the switches can operate at a fixed frequency with the new SVM scheme and have the same voltage stress as the dc-link voltage. In grid-connected application, the inverter can achieve ZVS in all the switches under the load with unity power factor or less. The aforementioned theory is verified in a 30-kW inverter prototype..

KEYWORDS:

  1. Grid connected
  2. soft switching
  3. space vector modulation (SVM)
  4. three-phase inverter
  5. zero-voltage switching (ZVS)

 SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

 Fig. 1. ZVS three-phase inverter.

 EXPECTED SIMULATION RESULTS:

 

 Fig. 2. Inverter output current and grid voltage (10 ms/div): (a) φu = φi , (b), φuφi = π/6, (c) φuφi = π/6.

Fig. 3. CE voltage and current of S6 (IGBT on) (5 μs/div).

Fig. 4. CE voltage and current of S6 (diode on) (2.5 μs/div).

 

 Fig. 5. CE voltage and current of S7 (25 μs/div).

Fig. 6. CE voltage and current of S7 , ibus, and iLr (10 μs/div).

 

Fig. 7. VCc and iLr (50 μs/div).

Fig. 8. Efficiency curve.

CONCLUSION:

In order to speed up the market acceptance of EVs/HEVs, the capital cost in charging infrastructure needs to lower as much as possible. This paper has presented an improved asymmetric half-bridge converter-fed SRM drive to provide both driving and on-board DC and AC charging functions so that the reliance on off-board charging stations is reduced.  The main contributions of this paper are: (i) it combines the split converter topology with central tapped SRM windings to improve the system reliability. (ii) the developed control strategy enables the vehicle to be charged by both DC and AC power subject to availability of power sources. (iii) the battery energy balance strategy is developed to handle unequal SoC scenarios. Even through a voltage imbalance of up to 20% in the battery occurs, the impact on the driving performance is rather limited. (iv) the state-of-charge of the batteries is coordinated by the hysteresis control to optimize the battery performance; the THD of the grid-side current is 3.7% with a lower switching frequency.  It needs to point out that this is a proof-of-concept study based on a 150 W SRM and low-voltage power for simulation and experiments. In the further work, the test facility will be scaled up to 50 kW.

REFERENCES:

[1] B. K. Bose, “Global energy scenario and impact of power electronics in 21st Century,” IEEE Trans. Ind. Electron., vol. 60, no. 7, pp. 2638- 2651, Jul. 2013.

[2] J. de Santiago, H. Bernhoff, B. Ekergård, S. Eriksson, S. Ferhatovic, R. Waters, and M. Leijon, “Electrical motor drivelines in commercial all-electric vehicles: a review,” IEEE Trans. Veh. Technol., vol. 61, no. 2, pp. 475-484, Feb. 2012.

[3] A. Chiba, K. Kiyota, N. Hoshi, M. Takemoto, S. Ogasawara, “Development of a rare-earth-free SR motor with high torque density for hybrid vehicles,” IEEE Trans. Energy Convers., vol. 30, no. 1, pp.175-182, Mar. 2015.

[4] K. Kiyota, and A. Chiba, “Design of switched reluctance motor competitive to 60-Kw IPMSM in third-generation hybrid electric vehicle,” IEEE Trans. Ind. Appl., vol. 48, no. 6, pp. 2303-2309, Nov./Dec. 2012.

[5] S. E. Schulz, and K. M. Rahman, “High-performance digital PI current regulator for EV switched reluctance motor drives,” IEEE Trans. Ind. Appl., vol. 39, no. 4, pp. 1118-1126, Jul./Aug. 2003.

Soft-Switching Current-Fed Push–Pull Converter for 250-W AC Module Applications

 

ABSTRACT:

In this paper, a soft-switching single-inductor push– pull converter is proposed. A push–pull converter is suitable for low-voltage photovoltaic ac module systems, because the step-up ratio of the high-frequency transformer is high, and the number of primary-side switches is relatively small. However, the conventional push–pull converter does not have high efficiency because of high-switching losses due to hard switching and transformer losses (copper and iron losses) as a result of the high turn ratio of the transformer. In the proposed converter, primary-side switches are turned ON at the zero-voltage switching condition and turned OFF at the zero-current switching condition through parallel resonance between the secondary leakage inductance of the transformer and a resonant capacitor. The proposed push–pull converter decreases the switching loss using soft switching of the primary switches. In addition, the turn ratio of the transformer can be reduced by half using a voltage-doubler of secondary side. The theoretical analysis of the proposed converter is verified by simulation and experimental results.

KEYWORDS:

  1. Current-fed push–pull converter
  2. Photovoltaic (PV) ac module
  3. Soft-switching

 SOFTWARE: MATLAB/SIMULINK

 CONTROL BLOCK DIAGRAM:

Fig. 1. Control block diagram of the dc–dc converter and dc–ac inverter using a microcontroller.

 EXPECTED SIMULATION RESULTS:

Fig. 2. (a) Carriers and a reference for PWM. (b) Waveforms of primary

switch S1 . (c) Waveforms of primary switch S2 .

Fig. 3. (a) Boost inductor current iLbst . (b) Resonant capacitor voltage vC r .

 Fig. 4. (a) Waveforms of tracking the MPP. (b) PWM according to MPPT. (c) Start flag of MPPT.

Fig. 5. Current and voltage waveforms of switch S1 according to ZVS and ZCS.

Fig. 6. Waveforms of resonant capacitor voltage and boost inductor current.

 CONCLUSION:

In this paper, the soft-switching single-inductor push–pull converter for PV ac module applications is proposed. Soft switching was confirmed at each part, and MPPT is performed for extracting the maximum power from the PV module. Switches of the primary side operate in the ZVS condition at turn-off and in the ZCS condition at turn-on. The proposed converter maintains a Vo of 400 V to provide ac 220 Vrms for dc–ac inverters. The maximum efficiency is 96.6%. These results were confirmed by simulation and verified by a 250-W experimental setup.

REFERENCES:

[1] S. B. Kjaer, J. K. Pedersen, and F. Blaabjerg, “A review of single-phase grid-connected inverters for photovoltaic modules,” IEEE Trans. Ind. Appl., vol. 41, no. 5, pp. 1292–1306, Sep. 2005.

[2] S. B. Kjaer, J. K. Pedersen, and F. Blaabjerg, “Power inverter topologies for photovoltaic modules: A review,” in Proc. IEEE. Ind. Appl. Conf., vol. 2, Oct. 2002, pp. 782–788.

[3] Y. Xue, L. Chang, S. B. Kjaer, J. Bordonau, and T. Shimizu, “Topologies of single-phase inverters for small distributed power generators: An overview,” IEEE Trans. Power Electron., vol. 19, no. 5, pp. 1305–1314, Sep. 2004.

[4] R. Gonzalez, J. Lopez, P. Sanchis, and L. Marroyo, “Transformerless inverter for single-phase photovoltaic systems,” IEEE. Trans. Power Electron., vol. 22, no. 2, pp. 693–697, Mar. 2007.

[5] T. Shimizu,K.Wada, andN.Nakamura, “Flyback-type single-phase utility interactive inverter with power pulsation decoupling on the DC input for an AC photovoltaic module system,” IEEE Trans. Power Electron.,, vol. 21, no. 5, pp. 1264–1272, Sep. 2006.

Full Soft-Switching High Step-Up Current-Fed DC-DC Converters with Reduced Conduction Losses

 

ABSTRACT:

Two variants of the full soft-switching high step-up DC-DC converter are proposed. The main advantage of the converters is the minimized conduction losses by the use of the four-quadrant switches and a specific control algorithm. Simulation was performed to verify the principle of operation and to estimate the losses.

 KEYWORDS:

  1. DC-DC power converters
  2. Photovoltaic systems
  3. Soft switching
  4. Step-up
  5. Isolated

 SOFTWARE: MATLAB/SIMULINK

 CIRCUIT DIAGRAM:

 

Fig. 1. Full soft-switching high step-up DC-DC converter

Fig. 2. Proposed converter topology with four four-quadrant switches.

EXPECTED SIMULATION RESULTS:

 Fig. 3. Simulated voltage and current waveforms of S1 (a), S2 (b), S7.1 (c), S5 (d) for the proposed converter topology with a single four-quadrant switch

CONCLUSION:

The proposed converters allow soft-switching of the both inverter and rectifier switches without any auxiliary passive elements and clamping circuits.

As seen from simulation results, the topology with a single four-quadrant switch has higher efficiency than the topology with four four-quadrant switches, but at the same time, it has few disadvantages that could affect the final choice of topology:

– Step-up factor is slightly lower than in the topology with four four-quadrant switches;

– The switching interval e (and the symmetrical interval in another half-period) must be of strictly right duration, which is equal to the time of current redistribution between switches S4 and S2. The shorter duration of this interval will result in high switching losses and, in extreme cases, can lead to damage of the switch S4. The significantly longer duration will result in current increase through the switch S2 and eventually may result in the boost inductor saturation.

– The original topology and the topology with four four quadrant switches does not have the problem with the longer duration of this switching interval and so they have lower requirements to the control system in dynamic mode. This means that proposed converter with four four-quadrant switches allows robust soft-switching commutation, which is hard to achieve in galvanically isolated current-fed DCDC converters.

The main disadvantage of the topologies is the presence of four switches in series in the inverter stage on the path of the current flow during the energy transfer interval. This leads to the conduction losses higher than in the conventional phase shifted full-bridge topology. Nevertheless the switching losses are lower due to the introduced soft-switching. It means that switching frequency could be increased while maintaining the efficiency at acceptable level.

Future work will be devoted to the experimental verification of the proposed converters and further control algorithm optimization.

 REFERENCES:

[1] A. Blinov, D. Vinnikov, and V. Ivakhno, “Full soft-switching high stepup dc-dc converter for photovoltaic applications,” 2014 16th European Conference on Power Electronics and Applications (EPE’14-ECCE Europe), pp. 1–7, Aug 2014.

[2] Y. Sokol, Y. Goncharov, V. Ivakhno, V. Zamaruiev, B. Styslo, M. Mezheritskij, A. Blinov, and D. Vinnikov, “Using the separated commutation in two-stage dc/dc converter in order to reduce of the power semiconductor switches’ dynamic losses,” Energy Saving. Power Engineering. Energy Audit, 2014.

[3] A. Blinov, V. Ivakhno, V. Zamaruev, D. Vinnikov, and O. Husev, “Experimental verification of dc/dc converter with full-bridge active rectifier,” 38th Annual Conference on IEEE Industrial Electronics Society (IECON 2012), pp. 5179–5184 , Oct 2012.

[4] R.-Y. Chen, T.-J. Liang, J.-F. Chen, R.-L. Lin, and K.-C. Tseng, “Study and implementation of a current-fed full-bridge boost dc-dc converter with zero-current switching for high-voltage applications,” IEEE Transactions on Industry Applications, vol. 44, no. 4, pp. 1218–1226, July 2008.

[5] J.-F. Chen, R.-Y. Chen, and T.-J. Liang, “Study and implementation of a single-stage current-fed boost pfc converter with zcs for high voltage applications,” IEEE Transactions on Power Electronics, vol. 23, no. 1, pp. 379–386, Jan 2008.

Zero-Voltage Switching Galvanically Isolated Current-Fed Full-Bridge DC-DC Converter

ABSTRACT:

This paper presents a new soft-switching technique for the current-fed full-bridge DC-DC converter that enables zero voltage switching of the input side inverter switches. To achieve this, the secondary side voltage doubler rectifier has to be realized with active switches. Two control channels synchronous with the control signals of the inverter switches are added for driving those switches. Zero voltage switching achieved is assisted with the body diodes that conduct current during soft-switching transients as a result of the leakage inductance current shaping from the secondary side. Moreover, the converter does not suffer from voltage overshoots thanks to natural clamping from the secondary side. Theoretical predictions were verified with simulation.

KEYWORDS:

  1. Zero-voltage switching
  2. Current-fed DC-DC converter
  3. Full-bridge
  4. Soft-switching
  5. Switching` control method

 SOFTWARE: MATLAB/SIMULINK

 CIRCUIT DIAGRAM:

Fig. 1. Galvanically isolated full-bridge current-fed DC-DC converter with controlled output rectifier stage.

EXPECTED SIMULATION RESULTS:

 Fig. 2. Simulated current and voltage waveforms along with control signals of the input and output side switches.

Fig. 3. Experimental current and voltage waveforms.

CONCLUSION:

The novel ZVS technique intended for the galvanically isolated full-bridge current-fed DC-DC converter with the controlled output rectifier stage were presented. It enables full ZVS in the input side current-fed inverter assisted with the leakage inductance and body diodes. Moreover, partial ZCS is provided in the secondary side assisted with the leakage inductance. Simulation study corroborates the theoretical predictions made. Experimental prototype operation was quite similar to the simulation model created in PSIM. Nevertheless, the prototype features oscillations caused by parasitic elements of the circuit and reverse recovery of the body diodes the input side MOSFETs. Further research will be aimed towards derivation of design guidelines that take into account reverse recovery effect and, consequently, result in high efficiency and low parasitic oscillations.

REFERENCES:

[1] Blaabjerg, F.; Zhe Chen; Kjaer, S.B., “Power electronics as efficient interface in dispersed power generation systems,” IEEE Transactions on Power Electronics, vol. 19, no. 5, pp. 1184-1194, Sept. 2004.

[2] Kouro, S.; Leon, J.I.; Vinnikov, D.; Franquelo, L.G., “Grid-Connected Photovoltaic Systems: An Overview of Recent Research and Emerging PV Converter Technology,” IEEE Industrial Electronics Magazine, vol. 9, no. 1, pp. 47-61, March 2015.

[3] Rathore, A.K.; Prasanna, U., “Comparison of soft-switching voltage-fed and current-fed bi-directional isolated Dc/Dc converters for fuel cell vehicles,” in Proc. ISIE’2012, pp. 252-257, 28-31 May 2012.

[4] Prasanna, U.R.; Rathore, A.K., “Extended Range ZVS Active-Clamped Current-Fed Full-Bridge Isolated DC/DC Converter for Fuel Cell Applications: Analysis, Design, and Experimental Results,” IEEE Transactions on Industrial Electronics, vol. 60, no. 7, pp. 2661-2672, July 2013.

[5] Iannello, C.; Shiguo Luo; Batarseh, I., “Small-signal and transient analysis of a full-bridge, zero-current-switched PWM converter using an average model,” IEEE Transactions on Power Electronics, vol.18, no.3, pp.793-801, May 2003.

Parasitics Assisted Soft-switching and Naturally Commutated Current-fed Bidirectional Push-pull Voltage Doubler  

 

ABSTRACT:

A snubberless current-fed push-pull dc/dc voltage doubler is proposed with zero voltage switching (ZVS) turn-on of low voltage current-fed devices by using the parasitic resonance between the drain-source capacitance of MOSFETs and the leakage inductance of the high frequency transformer. \Secondary modulation helps reduce switching losses further by obtaining zero current switching (ZCS) turn-off of primary devices and ZVS turn-on of secondary devices. Realizing ZCS of current-fed devices introduces natural zero current commutation and eliminates the traditional requirement of active-clamp or passive snubbers in current-fed topologies. Push-pull topology has low device and driver requirement. Voltage doubler offers 2x voltage gain reducing the device count by half on secondary that simplifies the transformer and control design and efficiently reduce the low frequency dc current harmonics. The proposed topology with novel modulation is suitable for interfacing energy storage and/or fuel cell stack with dc bus in FCVs or as frontend dc/dc converter in fuel cell inverters or connecting fuel cells to dc grid. Steady-state operation and analysis of proposed topology with proposed modulation has been studied. Design of a 1kW prototype is explained. Simulation results using PSIM 9.3 and experimental results of a 1 kW prototype have been demonstrated to verify the operation, proposed mathematical analysis, design, and the proposed claims.

 

 KEYWORDS:

  1. Current-fed converter
  2. Push-pull
  3. Natural commutation
  4. Soft-switching

 

SOFTWARE: MATLAB/SIMULINK

 

BLOCK DIAGRAM:

Fig.1. Architecture of a dc microgrid

 

Fig. 2. Architecture of a fuel cell car.

 

EXPECTED SIMULATION RESULTS:

      

Fig.3. Simulation results: (a) Gating signal of switch S1, current through switch S1, voltage across switch S1,(b) Gating signal of switch S2, current through switch S2, voltage across switch S2, (c) Current through boost inductor L, Current through series leakage inductance, Llk1, Current through series leakage inductance, Llk2, (d) Current through secondary devices S3 and S4, (e) Voltage Vab, output voltage Vo,Voltage across Llk1

 

Fig. 4. Experimental results: (a) Gating signal of switch S1, Vgs1, current through switch S1, Is1, drain-source voltage across switch S1, Vds1, (b) Current through boost inductor L, current through series leakage inductance, Llk1, (c) Current through secondary device S3, Is3, Gating pulse of S3, Vgs3, drain source voltage across switch S3, Vds3, (d) Voltage across leakage inductor Vlk1, voltage across transformer primary, Vab,

 

 CONCLUSION:

A truly snubberless current-fed push-pull dc/dc converter is proposed with zero current commutation and natural device voltage clamping. Push-pull configuration and voltage doubler circuit reduces the active device and driver count. It leads to a simple control design and implementation. Voltage doubler improves the gain by 2x and reduce transformer size. Traditionally, current-fed converters are hard-switching with device voltage spike at turn-off and require snubber circuits. In this paper, an innovative modulation is proposed to utilize circuit parasitics and introduce soft-switching of all devices. Zero current commutation and device voltage clamping are obtained without additional snubber making it a truly snubberless topology. The proposed modulation solves the classical problem in current-fed converters and makes a novel contribution. Furthermore, the proposed converter topology can efficiently eliminate the low frequency current ripples on the source (fuel cell stack) side. Low frequency dc current harmonics coming from power electronics have a negative impact on the lifetime and the performance of fuel cell power generation systems. The elimination of such low frequency current ripples may also simplify the control of fuel cell system ancillaries, such as air compressor. Thus, it is suitable for low voltage high current applications requiring high voltage gain, low ripple dc current, and precise operating point control. Major applications include interfacing energy storage with dc link in FCVs due to bidirectional nature and also as a front end dc-dc converter in case of fuel cell inverters. Switching losses are reduced significantly owing to soft-switching of all the devices. Synchronous rectification may be employed to obtain high efficiency. Steady state operation, analysis and circuit design have been explained in detail. Simulation results are presented to verify the concept and experimental results are demonstrated to show the performance and the claims.

 

REFERENCES:

[1] F. A. Farret, M. G. Simoes, “Integration of Alternative Sources of Energy,” 1st ed. New Jersey: Wiley, 2006.

[2] A. Khaligh and Z. Li, “Battery, ultracapacitor, fuel cell, and hybrid energy storage systems for electric, hybrid electric, fuel cell, and plugin hybrid electric vehicles: State of the art,” IEEE Trans. Veh. Technol., vol. 59, no. 6, pp. 2806–2814, Oct. 2009.

[3] A. Emadi and S. S. Williamson, “Fuel cell vehicles: Opportunities and challenges,” in Proc. IEEE Power Eng. Soc., 2004, pp. 1640–1645.

[4] K. Rajashekhara, “Power conversion and control strategies for fuel cell vehicles,” in Proc. IEEE Annu. Conf. Ind. Electron. Soc., 2003, pp. 2865– 2870.

[5] A. Emadi, S. S. Williamson, and A. Khaligh, “Power electronics intensive solutions for advanced electric, hybrid electric, and fuel cell vehicular power systems,” IEEE Trans. Power Electron., vol. 21, no. 3, pp. 567– 577, May 2006.

Full-Soft-Switching High Step-Up Bidirectional Isolated Current-Fed Push-Pull DC-DC Converter for Battery Energy Storage Applications

 

ABSTRACT

This paper presents a novel bidirectional current-fed push-pull DC-DC converter topology with galvanic isolation. The control algorithm proposed enables full-soft-switching of all transistors in a wide range of input voltage and power with no requirement for snubbers or resonant switching. The converter features an active voltage doubler rectifier controlled by the switching sequence synchronous to that of the input-side switches. As a result, full-soft-switching operation at a fixed switching frequency is achieved. Operation principle for the energy transfer in both directions is described, followed by verification with a 300 W experimental prototype. The converter has considerably higher voltage step-up performance than traditional current-fed converters Experimental results obtained are in good agreement with the theoretical steady-state analysis.

 

KEYWORDS

  1. Current-fed dc-dc converter
  2. Bidirectional converter
  3. Soft-switching
  4. ZVS
  5. ZCS
  6. Push-pull converter
  7. Switching control method

 

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM

Full-soft-switching CF push-pull converter proposed.

Fig. 1. Full-soft-switching CF push-pull converter proposed.

 

SIMULATION RESULTS

Simulation current and voltage waveforms of the switch S1.1.

Fig. 2. Simulation current and voltage waveforms of the switch S1.1.

Simulation current and voltage waveforms of the switch S1.2.

Fig. 3. Simulation current and voltage waveforms of the switch S1.2.

Simulation current and voltage waveforms of the switch S4.

Fig. 4. Simulation current and voltage waveforms of the switch S4.

CONCLUSION

A novel bidirectional current-fed push-pull converter with galvanic isolation was introduced. It features full-softswitching operation of all semiconductor components, while its DC voltage gain is higher than in traditional current-fed converters due to the utilization of the circulating energy for the input voltage step-up. As a result, it does not suffer from short intervals of energy transfer from the input side to the output side since at least half of the switching period is dedicated for this. Moreover, it does not require any clamping circuits, since the novel control algorithm features natural clamping of the switches at the current-fed side. Despite a relatively high number of semiconductor components, it shows the peak efficiency of 96.3%, which does not depend on the energy transfer direction for the corresponding operating point. Soft-switching operation with continuous current at the currentfed side makes the converter proposed suitable for residential battery energy storage systems. Further research will be directed towards experimental verification of the converter performance with a lithium iron phosphate battery.

 

REFERENCES

  1. Blaabjerg, and D.M. Ionel, “Renewable Energy Devices and Systems – State-of-the-Art Technology, Research and Development, Challenges and Future Trends,” Electric Power Components and Systems, vol.43, no.12, pp.1319-1328, 2015.
  2. C, Heymans, S, B. Walker, S. B. Young, M. Fowler, “Economic analysis of second use electric vehicle batteries for residential energy storage and load-levelling,” Energy Policy, vol. 71, pp. 22-30, Aug. 2014.
  3. Weniger, T. Tjaden, V. Quaschning, “Sizing of Residential PV Battery Systems,” Energy Procedia, vol. 46, pp. 78-87,2014.
  4. J. Chiang, K. T. Chang and C. Y. Yen, “Residential photovoltaic energy storage system,” IEEE Trans. Ind. Electron., vol. 45, no. 3, pp. 385-394, Jun 1998.
  5. X. Chen, H. B. Gooi and M. Q. Wang, “Sizing of Energy Storage for Microgrids,” IEEE Trans. Smart Grid, vol. 3, no. 1, pp. 142-151, 2012.

Full-Soft-Switching High Step-Up Bidirectional Isolated Current-Fed Push-Pull DC-DC Converter for Battery Energy Storage Applications

ABSTRACT:

This paper presents a novel bidirectional current fed push-pull DC-DC converter topology with galvanic isolation. The control algorithm proposed enables full-soft-switching of all transistors in a wide range of input voltage and power with no requirement for snubbers or resonant switching. The converter features an active voltage doubler rectifier controlled by the switching sequence synchronous to that of the input-side switches. As a result, full-soft-switching operation at a fixed switching frequency is achieved. Operation principle for the energy transfer in both directions is described, followed by verification with a 300 W experimental prototype. The converter has considerably higher voltage step-up performance than traditional current-fed converters Experimental results obtained are in good agreement with the theoretical steady-state analysis.

KEYWORDS:

  1. Current-fed dc-dc converter
  2. Bidirectional converter
  3. Soft-switching
  4. ZVS
  5. ZCS
  6. Push-pull converter
  7. Switching control method
  8. Naturally clamped

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

image001

Fig. 1. Full-soft-swithicng CF push-pull converter proposed.

EXPECTED SIMULATION RESULTS:
image002

Fig. 2. Experimental current and voltage waveforms of the switch S1.1

image003

Fig. 3. Experimental current and voltage waveforms of the switch S1.2.

image004

Fig. 4. Experimental current and voltage waveforms of the switch S4.

CONCLUSION:

A novel bidirectional current-fed push-pull converter with galvanic isolation was introduced. It features full-soft switching operation of all semiconductor components, while its DC voltage gain is higher than in traditional current-fed converters due to the utilization of the circulating energy for the input voltage step-up. As a result, it does not suffer from short intervals of energy transfer from the input side to the output side since at least half of the switching period is dedicated for this. Moreover, it does not require any clamping circuits, since the novel control algorithm features natural clamping of the switches at the current-fed side. Despite a relatively high number of semiconductor components, it shows the peak efficiency of 96.3%, which does not depend on the energy transfer direction for the corresponding operating point. Soft-switching operation with continuous current at the current fed side makes the converter proposed suitable for residential battery energy storage systems. Further research will be directed towards experimental verification of the converter performance with a lithium iron phosphate battery.

REFERENCES:

[1] F. Blaabjerg, and D.M. Ionel, “Renewable Energy Devices and Systems – State-of-the-Art Technology, Research and Development, Challenges and Future Trends,” Electric Power Components and Systems, vol.43, no.12, pp.1319-1328, 2015.

[2] C, Heymans, S, B. Walker, S. B. Young, M. Fowler, “Economic analysis of second use electric vehicle batteries for residential energy storage and load-levelling,” Energy Policy, vol. 71, pp. 22-30, Aug. 2014.

[3] J. Weniger, T. Tjaden, V. Quaschning, “Sizing of Residential PV Battery Systems,” Energy Procedia, vol. 46, pp. 78-87,2014.

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