Robust Sliding-Mode Control Design for a Voltage Regulated Quadratic Boost Converter

Abstract

A robust controller design to obtain output voltage regulation in a quadratic boost converter with high DC-gain is discussed in this paper. The proposed controller has an inner loop based on sliding mode control whose sliding surface is defined for the input inductor current. The current reference value of the sliding surface is modified by a proportional-integral (PI) compensator in an outer loop which operates over the output voltage error. The stability of the two-loop controller is proved by using the Routh-Hurwitz criterion, which determines a region in the - plane where the closed loop system is always stable. The analysis of the sliding mode-based control loop is performed by means of the equivalent control method while the outer loop compensator is derived by means of the Nyquist- based Robust Loop Shaping approach with the M-constrained Integral Gain Maximization technique (RLS-MIGO). Robustness is analyzed in depth taking into account the parameter variation related with the operation of the converter in different equilibrium points. Simulations and experimental results are presented to validate the approach for a 20 - 100 W quadratic boost converter stepping-up a low DC voltage (15 – 25 V DC) to a 400 V DC level.

Index Terms

1.      Quadratic boost converter

2.      Robust loop shaping

3.      Sliding-mode control

 

Circuit Diagram:

Fig. 1. Quadratic boost circuit configurations: a) ON-state; and b) OFF-state.

Expected Simulation Results:

Fig. 2. Transient responses to output power step disturbances in the extreme values of the converter operational range

Fig. 3. Transient response to input voltage step disturbances in the extreme values of the converter operational range.

Fig. 4. Transient response to a voltage reference step change in the extreme values of the converter operational range.

Conclusions

A complete description of a robust controller design obtaining output voltage regulation in a high DC-gain quadratic boost converter involving a sliding-mode current loop has been presented in this paper. The results show that this control scheme has a satisfactory performance regulating the output voltage in its overall operational range of output power and input voltage. The stability of the complete system has been treated as local by using the Routh-Hurwitz test constraining a stability region in the - plane which has been subsequently used as a reference to synthesize the PI compensator using the RLS-MIGO method. The stability and robustness of the overall system has been tackled by considering the possible variations in the output load or in the input voltage as parametric uncertainty. Several MATLAB simulations have been used to verify the theoretical approach and the converter expected performance when coping with important disturbances in the uncertain parameters. Moreover, experimental results using simple electronic circuits are in good agreement with the theoretical predictions and simulation results. The experiments have validated not only the high DC-gain capability of the quadratic boost converter operating with a hysteresis- based current controller but also the regulator robustness , ensured by the application of the loop shaping method in the PI synthesis. It can be concluded that the RLS-MIGO method is compatible with the sliding-mode approach providing an efficient solution to synthesize the proposed two-loop controller for a high-order topology such as the quadratic boost converter. Future works with the same converter will be devoted to the study of its possible discontinuous and critical conduction modes together with the associated design of an appropriate controller.

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, Sept. 2004.

[2] Q Li and P Wolfs, “A review of the single phase photovoltaic module integrated converter topologies with three different DC link configurations," IEEE Trans. Power Electron., vol. 3, no. 3, pp. 1320-1333, May. 2008.

[3] S Lee, P Kim and S Choi, “High step-up soft-switched converters using voltage multiplier cells,” IEEE Trans. Power Electron., vol. 28, no. 7, pp. 3379-3387, Jul. 2013.

[4] A Stupar, T Friedli, J Miniböck and J W Kolar, “Towards a 99% Efficient Three-Phase Buck-Type PFC Rectifier for 400-V DC Distribution Systems,” IEEE Trans. Power Electron., vol. 27, no. 4, pp. 1732-1744, Apr. 2012.

 [5] Rockwell Automation, “Common DC bus: Selection guide,” Publication DRIVES-SG001B-EN-P. Sep. 2005

RENEWABLE ENERGY SOURCES INTEGRATION AND CONTROL IN RAILWAY MICROGRID

ABSTRACT

 The traffic rail increase implies an increase in the electric energy consumption. Hybridizing the railway substations with hybrid energy sources based on renewable energy sources and storage units connected to a DC bus may be a solution to contribute to the partial independence of energy producers in the sector of traffic rail. A smart controlis highly recommended in order to avoid disturbing the traffic or the energy quality of railway lines. This paper proposes a reversible, self-adaptive, autonomous and intelligent distributed generator connected to the catenary thanks to the DC bus distributed control by the multi-agent system. The results analysis has shown that the proposed control architecture can be a solution to face the issues related to the traffic railway issues.

INDEX TERMS

1.      Railway microgrid

2.      Braking and tracking energy

3.      Renewable energy sources

4.      Penalty costs

5.      Multi agent system

6.      Jade

7.       MacsimJX

8.      Matlab Simulink

BLOCK DIAGRAM:

Fig. 1. HSS architecture

 EXPECTED SIMULATION RESULTS:

Fig. 2. The considered driving cycle

Fig. 3. Resultant current from tracking and braking process

Fig.4. Current generated by RES

Fig. 5. Battery DC-DC converter output current

Fig. 6. The line current

Fig. 7. Battery SOC evolution

Fig. 8. Subscribed power gain

Fig. 9. Subscribed power exceeding removal

Fig. 10. Penalty cost removal

Fig. 11. DC bus voltage evolution

CONCLUSION

 

This paper deals the DEM by MAS in the railway microgrid with HSS based on HPGS to meet the limitations of rail transportation systems in terms of energy saving. The HPGS consists of a multi-source system with decentralized energy sources with different capacities and a different generation, therefore, judicious use and integration of each element were respected. Reducing the subscribed power, eliminating the voltage drop in the line due to the acceleration and leading to the subscribed power exceeding and avoiding the voltage rise due to the deceleration by consuming the total of the regenerative energy not recovered by the other trains in the line, remain the main issues that should be taking into account while hybridizing the substation without modifying the existing architecture. Thereby, this paper meets the mentioned limitations and constraints by designing reversible, active, intelligent, self-adaptive, and autonomous DG connected to the catenary thanks to the distributed DC bus voltage control by MAS. It was shown the ability of the proposed control to reduce the subscribed power and to omit the subscribed power overrun by the RES generation and the storage system which is represented by the battery. The penalty costs related to the subscribed power exceeding and the RES intermittence and also to the acceleration and deceleration were suppressed, thanks to the simultaneous control of the battery with the generation of the RES. The results also showed the stability and continuity of the system thanks to the effectiveness of the proposed control.

REFERENCES

[1] R.R.Pecharroman and al, “Riding the Rails to DC Power Efficiency: Energy efficiency in dc-electrified metropolitan railways”, IEEE Electrification Magazine, vol. 2, No.3, pp. 32 – 38 , 2014 [2] Boudoudouh Soukaina, and Mohammed Maâroufi. "Smart control in a DC railway by Multi Agent System (MAS)." In Electrical Systems for Aircraft, Railway, Ship Propulsion and Road Vehicles & International Transportation Electrification Conference (ESARS-ITEC), International Conference on, pp. 1-6. IEEE, 2016. [3] Hajizadeh, A., Golkar, M. A., "Intelligent power management strategy of hybrid distributed generation system", Elsevier, electrical Power and Energy systems, pp. 783-795, 2007 [4] H.Ibrahim and al “Integration of Wind Energy into Electricity Systems: Technical Challenges and Actual Solutions”, Energy proceedia, vol. 6, pp. 815_824, 2011 [5] B. Robyns and al, “Electricity production from renewables energies”, ISTE Wiley 2012.

 

Quasi Cascaded H-Bridge Five-Level Boost Inverter

ABSTRACT

Latterly, multilevel inverters have become more attractive for researchers due to low total harmonic distortion (THD) in the output voltage and low electromagnetic interference (EMI). This paper proposes a novel single-stage quasi-cascaded H-bridge five-level boost inverter (qCHB-FLBI). The proposed five-level inverter has the advantages over the cascaded H-bridge quasi-Z-source inverter (CHB-qZSI) in cutting down passive components. Consequently, size, cost, and weight of the proposed inverter are reduced. Additionally, the proposed qCHB-FLBI can work in the shoot-though state. A capacitor with low voltage rating is added to the proposed topology to remove an offset voltage of the output AC voltage when the input voltages of two modules are unbalanced. Besides, a simple PID controller is used to control the capacitor voltage of each module. This paper presents circuit analysis, the operating principles, and simulation results of the proposed qCHB-FLBI. A 1.2-Kva laboratory prototype was constructed based on a DSP TMS320F28335 to validate the operating principle of the proposed inverter.

INDEX TERMS

Cascaded H-bridge inverter, five-level inverter, quasi-Z-source inverter, boost inverter, shoot-through state

CONVENTIONAL DIAGRAM:

Fig. 1. Conventional CHB five-level inverters based on (a) DC-DC boost converter

EXPECTED SIMULATION RESULTS:

 

Fig. 2. Simulation results when Vdc1 = Vdc2 = 50 V. From top to bottom: (a) five-level output voltage, load and inductor currents, VC1, VC2, Vdc1 and Vdc2, (b) inductor currents, capacitor voltages, DC-link and diode Da1 voltages of module 1, DC-link and diode Da2 voltages of module 2, (c) harmonic spectrum of five-level output voltage, and (d) harmonic spectrum of load current

Fig. 3. Simulation results when Vdc1 = 50 V and Vdc2 = 60 V. From top to bottom: (a) five-level output voltage, load and inductor currents, VC1, VC2, Vdc1, Vdc2 and VCd, (b) five-level output voltage, inductor currents, capacitor voltages, DC-link and diode Da1 voltages of module 1, DC-link and diode Da2 voltages of module 2, (c) harmonic spectrum of five-level output voltage, and (d) harmonic spectrum of load current.

CONCLUSION

A New Single-Phase Single-Stage CHB Five-Level Inverter With Boost Voltage Ability Has Been Proposed In This Paper. The Proposed Inverter Has The Following Main Features As: Five-Level Output Voltage, Reduction In Number Of Passive Components And Shoot-Through Immunity. With The Simple PID Controller, A Constant Capacitor Voltage Can Be Achieved With An Excellent Transient Performance Which Enhances The Rejection Of Disturbance, Including The Input Voltage And Load Current Variations. Also, Circuit Analysis And PWM Control Strategy For The Proposed System Are Shown. Simulation And Experimental Results Are Shown To Verify The Validity Of The Proposed Qchb-FLBI.

REFERENCES

[1] S. Kouro, M. Malinowski, K. Gopakumar, J. Pou, L. G. Franquelo, B. Wu, J. Rodriguez, M. A. Pérez, and J. I. Leon, “Recent advances and industrial applications of multilevel converters,” IEEE Trans. Ind. Electron., vol. 57, no. 8, pp. 2553– 2580, Aug. 2010.

[2] 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, July 2010.

[3] G. Farivar, B. Hredzak, and V. G. Agelidis, “A DC-side sensorless cascaded H-bridge multilevel converter-based photovoltaic system,” IEEE Trans. Ind. Electron., vol. 63, no. 7, pp. 4233–4241, July 2016.

[4] J. Chavarría, D. Biel, F. Guinjoan, C. Meza, and J. J. Negroni, “Energy-balance control of PV cascaded multilevel grid-connected inverters under level-shifted and phase-shifted PWMs,” IEEE Trans. Ind. Electron., vol. 60, no. 1, pp. 98–111, Jan. 2013.

[5] M. Coppola, F. D. Napoli, P. Guerriero, D. Iannuzzi, S. Daliento, and A. D. Pizzo, “An FPGA-based advanced control strategy of a grid-tied PV CHB inverter,” IEEE Trans. Power Electron, vol. 31, no. 1, pp. 806–816, Jan. 2016.

Quadratic boost converter with low-output voltage ripple

Abstract

This study proposes a non-isolated quadratic boost converter (QBC) that features a low-output-voltage ripple with respect to traditional QBCs. This advantage is in contrast with other topologies that require a higher amount of stored energy by capacitors to achieve the same output-voltage ripple specification. This benefit permits to design a compact converter, since the size of capacitors is proportional to their energy storage rating. Moreover, the proposed transformerless topology is suitable for applications that require high-voltage gains as in the case of renewable energy applications. The main properties of the converter are corroborated as well as its advantages by providing mathematical models, analytical waveforms and experiments.

Block Diagram:

 

Fig. 1  Traditional QBC

(a) Single switch QBC, quadratic boost converter [8–12], (b) Emerging QBC with

reduced energy stored, reduced energy-stored quadratic boost converter in [14, 15]

 

Expected Simulation Results:

Fig. 2  Experimental waveforms

(a) Currents through inductors and voltages across switches S1 and S2, (b) Output voltage and voltages across capacitors C1 and C2 with respect to the PWM signal, (c) Output voltage and voltages across capacitors C1 and C2 in AC mode, with respect to the PWM signal of switch with Vg = 90 V and D = 0.4

Fig. 3  Experimental waveforms

(a) Currents through inductors and voltages across switches S1 and S2, (b) Output voltage and voltages across capacitors C1 and C2 with respect to the PWM signal, (c) Output voltage and voltages across capacitors C1 and C2 in AC mode, with respect to the PWM signal of switch with Vg = 62 V and D = 0.5

 

Fig. 4  Experimental waveforms

(a)     Currents through inductors and voltages across switches S1 and S2, (b) Output voltage and voltages across capacitors C1 and C2 with respect to the PWM signal, (c) Output voltage and voltages across capacitors C1 and C2 in AC mode, with respect to the PWM signal of switch with Vg = 40 V and D = 0.6

Conclusions

 

In this paper, a novel quadratic dc–dc converter topology is presented. The main advantages of the proposed topology are: (i) the voltage gain is quadratic type, which enables the converter to work in a wide input voltage range within a reduced range of duty cycle. (ii) A voltage ripple cancelling technique can be applied to the output voltage, and then for the same energy stored in capacitors, the output-voltage ripple is smaller than existing topologies; this allows using smaller capacitors for the same voltage ripple specification. Several tests were performed over the full operation range, defined with a realistic example. Experimental results showed that the proposed converter produces a lower voltage ripple in the full operation range compared with traditional topologies. The previous propositions are demonstrated using analytical formulations and waveforms as well as by experimental results.

References

 

[1] Lessa Tofoli, F., de Castro Pereira, D., de Paula, W.J., et al.: ‘Survey on nonisolated high-voltage step-up dc–dc topologies based on the boost converter’, IET Power Electron, 2015, 8, (10), pp. 2044–2057

 

	[2] Erickson, R.W., Maksimovic, D.: ‘Fundamentals of power electronics’ (Springer, New York, USA, 2001, 2nd edn.) [3] Rosas-Caro, J.C., Ramirez, J.M., Peng, F.Z., et al.: ‘A DC–DC multilevel boost converter’, IET Power Electron, 2010, 3, (1), pp. 129–137 [4] Gandomkar, A., Parastar, A., Seok, J.: ‘High-power multilevel step-up DC/DC converter for offshore wind energy systems’, IEEE Trans. Ind. Electron., 2016, 63, (12), pp. 7574–7585 [5] Rosas-Caro, J.C., Mancilla-David, F., Mayo-Maldonado, J.C., et al.: ‘A                   transformerless high-gain boost converter with input current ripple cancelation at a selectable duty cycle’, IEEE Trans. Ind. Electron., 2013, 60, (10), pp. 4492–4499

 

Power Factor Improvement in Modified Bridgeless Landsman Converter Fed EV Battery Charger

Abstract

 This work deals with the design and implementation of a new charger for battery operated electric vehicle (BEV) with power factor improvement at the frontend. In the proposed configuration, the conventional diode converter at the source end of existing electric vehicle (EV) battery charger, is eliminated with modified Landsman power factor correction (PFC) converter. The PFC converter is cascaded to a flyback isolated converter, which yields the EV battery control to charge it, first in constant current mode then switching to constant voltage mode. The proposed PFC converter is controlled using single sensed entity to achieve the robust regulation of DC-link voltage as well as to ensure the unity power factor operation. The proposed topology offers improved power quality, low device stress, low input and output current ripple with low input current harmonics when compared to the conventional one. Moreover, to demonstrate the conformity of proposed charger to an IEC 61000-3-2 standard, a prototype is built and tested to charge a 48V EV battery of 100Ah capacity, under transients in input voltage. The performance of the charger is found satisfactory for all the cases.

Keywords

1.      Battery Operated Electric Vehicle

2.      Battery Charger

3.      Power Factor Improvement

4.      Modified Landsman Converter

5.      Power Quality

Conclusion

An improved EV charger with modified BL Landsman converter followed by a flyback converter has been proposed, analyzed, and validated in this work to charge an EV battery with inherent PF Correction. The design and control of the proposed EV charger in DCM mode have offered the advantage of reduced number of sensors at the output. Moreover, the proposed BL converter has reduced the input and output current ripples due to inductors both in input and output of the converter. A prototype has been developed and operation of the charger has been verified by the experimental results under steady state and sudden fluctuations in input voltage. The results from the hardware validation show that the performance of proposed charger is found satisfactory for improved power quality based charging of EV battery. Moreover, the input current THD is reduced as low as 4.3% to meet the recommended IEC 61000-3-2 standard guidelines for power quality. Therefore, proposed BL converter fed charger aims at cost effective, reliable and suitable option to replace the conventional lossy and inefficient EV battery charger

References

[1] Wencong Su, Habiballah Eichi, Wente Zeng and Mo-Yuen Chow, “A survey on the electrification of transportation in a smart grid environment,” IEEE Transactions Industrial Informatics, vol. 8, no. 1, pp. 1-10, Feb. 2012.

[2] Ching Chuen Chan, “The state of the art of electric, hybrid, and fuel cell vehicles,” Proc. IEEE, vol. 95, no. 4, pp. 704–718, Apr. 2007

[3] Kaushik Rajashekara, “Present status and future trends in electric vehicle propulsion technologies,” IEEE J. Emerg. Sel. Topics Power Electronics., vol. 1, no. 1, pp. 3–10, Mar. 2013.

[4] Juan C. Gomez and Medhat M. Morcos, “Impact of EV battery chargers on the power quality of distribution systems,” IEEE Transactions Power Del., vol. 18, no. 3, pp. 975–981, Jul. 2003.

[5] Luca Solero, “Nonconventional on-board charger for electric vehicle propulsion batteries,” IEEE Transactions Vehicular Technology, vol. 50, no. 1, pp. 144-149, Jan 2001