Performance Analysis of Solar PV array and Battery Integrated Unified Power Quality Conditioner for Microgrid Systems

 ABSTRACT:

In this work, a methodology for implementation of an automated transition of a solar PV array and battery integrated unified power quality conditioner (PV-BUPQC) between standalone and grid connected modes of operation is presented and analyzed. This system consists of a shunt and series active filters connected back to back with a common DC-link. The system addresses the issue of the integrating power quality improvement along with the generation of clean energy. Moreover, due to the automated transition, the critical loads have continuous power supply irrespective of grid availability. The key challenges addressed are implementation of automated transition in a PV-B-UPQC system with minimal disturbance to the local loads. The system operation is validated through experimentation under a number of dynamic conditions such as automated transition, supply voltage variations, unavailability of the grid, variation in solar power generation, load variation, etc., which are typically encountered in a modern distribution network.

KEYWORDS:

1.      Power quality

2.      Unified power quality conditioner

3.      Solar PV Generation

4.      Battery energy storage

5.      Automated transition

6.      Constant power generation

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

The design and performance of solar PV and battery integrated UPQC have been presented in this work. Due to the presence of energy storage in form of battery bank, the system operates in standalone mode of operation whenever grid is not available thus maintaining continuity of power supply to critical loads. Moreover, the system mitigates power fluctuations occurring in PV power generation due to weather conditions, thus enabling smooth power generation. This leads to increased stability of the overall system. The behavior of the system under steay state has been found satisfactory and the PCC currents meet the THD limits prescribed in the IEEE-519 standard.

The response of the PV-B-UPQC has been extensively evaluated under both standalone and grid connected modes of operation. The response of PV-B UPQC is found satisfactory under various conditions of irradiation variation, load unbalance and sags/swells in PCC voltage. Under all these disturbance conditions, the PV-B-UPQC is able to feed constant power into distribution network. The system automatically changes from the grid-tied operation to islanded operation and vice versa with minimal disturbance to the sensitive and critical load. The three wire PV-B-UPQC is suitable for the systems with operating with sensitive and critical load such as in data centers, hospitals, factories where uninterrupted power supply is of prime importance. The integration of battery and renewable energy, enables minimum dependence on the grid for power demand while the surplus PV power can support the grid by giving power to nearby loads at PCC.

REFERENCES:

[1] S. Singh, B. Singh, G. Bhuvaneswari, and V. Bist, “A power quality improved bridgeless converter-based computer power supply,” IEEE Transactions on Industry Applications, vol. 52, no. 5, pp. 4385–4394, Sep. 2016

[2] A. K. Giri, S. R. Arya, and R. Maurya, “Compensation of power quality problems in wind-based renewable energy system for small consumer as isolated loads,” IEEE Transactions on Industrial Electronics, vol. 66, no. 11, pp. 9023–9031, Nov. 2019.

[3] N. Saxena, I. Hussain, B. Singh, and A. L. Vyas, “Implementation of a grid-integrated pv-battery system for residential and electrical vehicle applications,” IEEE Transactions on Industrial Electronics, vol. 65, no. 8, pp. 6592–6601, Aug. 2018.

[4] S. Roy Ghatak, S. Sannigrahi, and P. Acharjee, “Multi-objective approach for strategic incorporation of solar energy source, battery storage system, and dstatcom in a smart grid environment,” IEEE Systems Journal, vol. 13, no. 3, pp. 3038–3049, Sep. 2019.

[5] K. K. Prasad, H. Myneni, and G. S. Kumar, “Power quality improvement and pv power injection by dstatcom with variable dc link voltage control from rsc-mlc,” IEEE Transactions on Sustainable Energy, vol. 10, no. 2, pp. 876–885, Apr. 2019.

Active Power Filter for Harmonic Mitigation of Power Quality Issues in Grid Integrated Photovoltaic Generation System

 ABSTRACT:

 

Single phase supply scheme tied with Photovoltaic arrangement (PV) employed on perturbed & observed (P&O) maximum energy point tracking technique with shunt active power filter allied to a rectifier feed R-L nonlinear load. The traditional Perturbed & Observed technique maximum energy point tracking topology is applied to attained maximum output power from Photovoltaic array(PVA), Proportional Integral conventional controller with phase detector (PD) phase locked loop (PLL) synchronization are executed to produce reference current. It provide at control unit of pulse width modulation topology( PWM) is utilized in inverter to get steady output voltage. Self supported DC bus PWM converter is regulated from PV array. In proposed architecture is minimized total harmonic pollution existing in supply current owing to power electronic load (PEL). Total current harmonic pollution (THDi) is compensated using dynamic filter shunt active power filter (SAPF) and power factor obtain better later than compensation. Hence, reactive power (KVAR) is delivered through system decrease and active power (KW) enhance. The suggested scheme has been implemented by way of MATLAB/SIMULINK 2015(a) environment.

KEYWORDS:

 

1.      Shunt Active Power Filter (SAPF)

2.      Photovoltaic Array (PVA)

3.      Proportional Integral controller

4.      Pulse width Modulated (PWM) Converter

5.      Maximum Power Point Tracking (P & O) Scheme

 

SOFTWARE: MATLAB/SIMULINK

 CONCLUSION:

In this research paper SAPF based on phase detector circuit (PLL) for unit vector generation with traditional PI controller is implemented. This controller regulates DC side voltage, reference current generated by PI conventional controller and positive progression predictor PLL synchronization unit. Hystersis band current control (HBCC) is employed to produce gate signal for voltage source inverter (VSI). The source current THD is abridged to fewer than 5% that is in accordance IEEE-519 standards for harmonic. Active power is improved by dynamic filtering using SAPF and decrease in reactive power consequently, power factor level is become finer.

REFERENCES:

[1] M. Singh, V. Khadkikar, A. Chandra, and R. K. Varma,“Grid Interconnection of Renewable Energy Sources at the Distribution Level With Power-Quality Improvement Features” IEEE Transactions on Power Delivery, vol. 26, no. 1, January 2011.

[2] S. Agrawal, Seemant Chorsiya, D.K Palwalia, “Hybrid Energy Management System design with Renewable Energy Sources (Fuel Cells, PV Cells and Wind Energy): A Review”, IJSET, vol. 6, no. 3, pp.174-177, 2018. DOI : 10.5958/2277 1581.2017.00104.8.

[3] M. G. Villalva, J. R. Gazoli and E. R. Filho, “Modeling and circuit based simulation of photovoltaic arrays”, Brazilian Power Electronics Conference, Bonito-Mato Grosso do Sul, pp. 1244-1254, 2009.

[4] S. Agrawal and D. K. Palwalia, “Analysis of standalone hybrid PVSOFC-  battery generation system based on shunt hybrid active power filter for harmonics mitigation.” IEEE Power India International Conference (PIICON) pp. 1-6, 2016.

[5] M. M. Hashempour, M. Savaghebi, J. C. Vasquez and J. M. Guerrero, “A Control Architecture to Coordinate Distributed Generators and Active Power Filters Coexisting in a Microgrid”, IEEE Transactions on Smart Grid, vol. 7, no. 5, pp. 2325-2336, Sept. 2016.

 

Compact Regenerative Braking Scheme for a PM BLDC Motor Driven Electric Two-Wheeler

ABSTRACT:

 Regenerative method of braking of an electric vehicle (EV) helps in efficient utilization of the battery power to increase the range of the vehicle. Methods described in literature for the regeneration use complex control algorithms to deal with the energy flow during the transition from the motoring mode to the regenerative braking mode of PM BLDC motor driven EV. In this paper, a simple method to control the power flow from the motor to the battery by changing the switching sequence given to the inverter used in the PM BLDC motor drive is presented. The newly presented method gives lower braking time and higher regeneration, and also does not necessitate any additional converters or ultra-capacitors.

KEYWORDS:

1.      Electric two wheeler

2.      Electric vehicle (EV)

3.       Hub motor

4.      Motor

5.      PM BLDC Motor

6.      Regenerative braking

 SOFTWARE: MATLAB/SIMULINK

 CONCLUSION:

The line back-EMF based regeneration method presented in this paper delivers far better performance than the mechanical braking in two-wheeler EVs also. Further, the presented method is the simplest one among the known regenerative methods in terms of the simplicity of the system, ease of implementation and also the higher braking torque developed. In this method, a noticeable power is fed back to the battery. The range of the EV is obviously increased.

 REFERENCES:

[1] J. W. Dixon, and M. E. Ortlizar, “Ultracapacitors + DC–DC Converters in Regenerative Braking System,” IEEE Aerospace andElectronic Systems magazine, Vol. 17, No. 8, pp. 16–21, August 2002.

[2] J. Cao, B. Cao, Z. Bai and W. Chen,” Energy regenerative Fuzzy Sliding mode Controller design for Ultra capacitor –Battery Hybrid Power Electric Vehicle,” Proceedings of the IEEE Int. Conf. on Mechatronics and Automation, , pp. 1570–1575, August 2007.

[3] J. Cao and B. Cao,”Fuzzy-logic - Based Sliding Mode Controller Design for Position -Sensorless Electric vehicle,” IEEE Trans.Power Electron. vol. 24, no. 10, pp. 2368-- 2378, October 2009.

[4] M. Ye, Z. F. Bai, and B. Cao, “Robust H2/Infinity Control for Regenerative Braking of Electric Vehicles,” Proceedings of the IEEE Int. Conf. on Control and Automation, pp. 1366–1370, May/June 2007

[5] J. Cao, B. Cao, Z. Bai and P. Xu , ” Regenerative – Braking Sliding mode Control of Electric Vehicle based on Neural network Identification,” Proceedings of the IEEE Int. Conf. on Advanced Intelligent Mechatronics, pp. 1219–1224, July 2008.

Novel Single Stage Power Factor Corrected LED Driver Topology for Space Constrained Applications of Aircraft Exterior Lighting System

ABSTRACT:

 This paper proposes a novel converter topology based on a single stage LED driver with Power Factor Correction (PFC) which is optimized for weight, volume and cost, for space constrained environments such as Aerospace exterior lighting product. The proposed topology utilizes a single switch to harmonize the input current as well as control the intensity of lighting system. A typical Power Factor Pre-regulator (PFP) uses a bulk energy storage capacitor, which is subjected to wear out a higher altitudes due to low pressure conditions and freezes a negative temperatures, resulting in poor reliability converter for Aerospace applications. Unlike a regular Power Factor Pre-regulator (PFP), the proposed topology avoids the use of bulk energy storage capacitor which results in a fast transient response with enhanced reliability, reduced board real estate and weight. The proposed LED driver topology can control the LED current with both Buck and Boost mode of control, making it a good choice for applications with wide input voltage variation. A 110 W prototype based on proposed converter was built to verify the operation of proposed topology. The experimental results are in line with the predicted performance. The proposed converter is able to achieve a power factor of 0.988 with an input current THD of < 10%.

SOFTWARE: MATLAB/SIMULINK

 CONCLUSION:

This paper presents a novel LED driver topology, capable of input power factor correction, for space constrained applications, such as Aerospace exterior lighting product line. Due to the compact design of the proposed LED driver topology, it can be of great advantage for an integrated power supply solution for Aerospace exterior lighting product offerings. The proposed LED driver topology can control the LED current with both Buck and Boost mode of control, making it a good choice for applications with wide input voltage variation. The proposed LED driver topology has been verified by mathematical analysis, circuit simulation and performance has been demonstrated experimentally as well. The proposed LED driver topology promises an appreciable amount of savings in term of real estate, power loss, and heat sink requirements while enhancing the power density of the converter and its reliability. Typically, it’s the bulk output capacitor that wears out with pressure variation (wear out phenomenon accelerates at altitudes more than 8000m due to the reduced pressures); which can be avoided with the proposed topology. Depending upon the load (number of LEDs) and  input voltage; in order to protect LEDs, a reverse blocking diode may be required during the Buck operation. For Boost application, reverse blocking diode will not be required even with today’s technology. Authors have been granted a U.S. Patent 9363291 [8] against the propose novel LED driver topology.

REFERENCES:

[1] L. H. Dixon, "High Power Factor Preregulators for Off- Line Power Supplies," Unitrode Power Supply Design Seminar Manual SEM600, 1988. (Republished in subsequent Manuals)

[2] Spiazzi, G., and Mattavelli, P. (1994) “Design criteria for power factor preregulators based on SEPIC and Cuk converters in continuous conduction mode,” IEEE IAS Conference Record, 1994, 1084-1089.

[3] Z. Ye, F. Greenfeld, and Z. Liang, “Single-stage offline SEPIC converter with power factor correction to drive high brightness LEDs,” in Proc. IEEE Appl. Power Electron. Conf., 2009, pp. 546–553.

[4] C.Zhou and M.Jovanovic, "Design Trade-offs in Continuous Current-Mode Controlled Boost Power-Factor Correction Circuits", HFPC Cod. Proc., 1992, pp. 209-220

[5] L. H. Dixon, "Average Current Mode Control of Switching Power Supplies," Unitrode Power Supply Design Seminar Manual SEM700, 1990

 

The Study of Single-phase PWM Rectifier Based on PR Control Strategy

 ABSTRACT:

Synchronous PI controller is usually used to track current in three-phase PWM rectifier with zero steady-state error which is difficult to achieve in the single-phase system. A novel proportional-resonant (PR) control scheme for single-phase PWM rectifier is proposed in the paper. Compared with traditional PI control and current hystereis control (CHC) methods, the PR control structure is simple and can reduce control time delay significantly. The simulation results verify the feasibility of the proposed control scheme in the disturbance rejection. In addition, sinusoidal current zero static error control can be achieved without a coordinate transformation and the DC voltage can automatically adjust to changes of grid voltage, load value and frequency which contributes to energy conversion and bidirectional flow of electricity.

KEYWORDS:

1.      Single-phase rectifiers

2.      CHC control

3.      PR-based control

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

From the above conducted studies, one can conclude that PR-based Control strategy for single-phase PWM rectifier presents better steady-state and can successfully achieve accurate regulation with fast dynamic response with minimum harmonic distortions. The simulation results show that sinusoidal current zero static error control can be achieved without a coordinate transformation and the DC voltage could automatically adjust to changes of grid voltage, load value and frequency which contributes to energy conversion and bidirectional flow of electricity. The control algorithm is easy to be realized while the robustness and power quality is improved. The highlight of paper lies in applying PR regulator to the adjustment of sinusoidal AC current zero static error , building the system model of single-phase PWM rectifier in MATLAB/Simulink with CHC and PR control scheme respectively and giving proper comparisons to some degree.

 REFERENCES:

[1] Song H.S, Nam K, Instantaneous Phase-angle Estimation Algorithm Under Unbalanced Voltage-sag Condition, IEEE Proc Generation, Transmission, and Distribution, Vol.147, No.6, 409-415, 2000.

[2] Zmood D.N, Holmes D.G, Stationary Frame Current Regulation of PWM Inverters with Zero Steady-state Error, IEEE Transactions on Power Electronics, Vol.18, No.3, 814-822, 2003.

[3] Yuan X, Merk W, Stemmler H, Stationary-frame Generalized Integrators for Current Control of Active Power Filters with Zero Steady-state Error for Current Harmonics of Concern Under Unbalance and Distorted Operating Conditions, IEEE Trans on Industry Applications, Vol.38, No.2, 523-532, 2002.

 [4] ZHAO Qinglin, GUO Xiaoqiang, WU Weiyang, Research on Control Strategy for Single-phase Grid-connected Inverter, Proceedings of the CSEE, 60-64, 2007.

 [5] JIANG Jun-feng, LIU Hui-jin, CHEN Yun-ping, A Novel Double Hystersis Current Control Method of Active Power Filter with Voltage Space Vector. Proceedings of the CSEE, Vol.24, No.10, 82-86, 2004.

Sensor-Less Five-Level Packed U-Cell (PUC5) Inverter Operating in Stand-Alone and Grid-Connected Modes

ABSTRACT:

 In this paper a new mode of operation has been introduced for Packed U-Cell (PUC) inverter. A sensor-less voltage control based on redundant switching states is designed for the PUC5 inverter which is integrated into switching process. The sensor-less voltage control is in charge of fixing the DC capacitor voltage at half of the DC source value results in generating symmetric five-level voltage waveform at the output with low harmonic distortion. The sensor-less voltage regulator reduces the complexity of the control system which makes the proposed converter appealing for industrial applications. An external current controller has been applied for grid-connected application of the introduced sensor-less PUC5 to inject active and reactive power from inverter to the grid with arbitrary power factor while the PUC auxiliary DC bus is regulated only by sensor-less controller combined with new switching pattern. Experimental results obtained in stand-alone and grid-connected operating modes of proposed PUC5 inverter prove the fast response and good dynamic performance of the designed sensorless voltage control in balancing the DC capacitor voltage at desired level.

KEYWORDS:

1.      Multilevel Inverter

2.      Packed U-Cell

3.      Sensor-Less Voltage Regulator

4.      PUC5

5.      5-Level Inverter

6.      Power Quality

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

The PUC5 inverter has been proposed in this paper while the capacitor voltage is balanced without involving any external controller and voltage feedback sensors. The proposed sensor-less voltage controller has been integrated into switching technique to work as open-loop system with reliable results. Moreover, another controller has been designed for the PUC5 inverter to work as unity power factor grid-connected inverter. Low harmonics components in both voltage and current waveforms generated by PUC5, no need to bulky output filters, reliable and good dynamic performance in variable conditions (including change in DC source, load, power amount injected to the grid), requiring no voltage/current sensor in stand-alone mode, low manufacturing costs and miniaturized package due to using less components and etc are interesting advantages of the introduced PUC5 topology which have been proved by experimental results in both stand-alone and grid-connected modes. The presented PUC5 inverter can be a challenging candidate for conventional photovoltaic application inverters.

REFERENCES:

[1] H. Abu-Rub, M. Malinowski, and K. Al-Haddad, Power electronics for renewable energy systems, transportation and industrial applications: John Wiley & Sons, 2014.

[2] L. G. Franquelo, J. Rodriguez, J. I. Leon, S. Kouro, R. Portillo, and M. A. M. Prats, "The age of multilevel converters arrives," IEEE Ind. Electron. Mag., vol. 2, no. 2, pp. 28-39, 2008.

 [3] C. Cecati, F. Ciancetta, and P. Siano, "A multilevel inverter for photovoltaic systems with fuzzy logic control," IEEE Trans. Ind. Electron., vol. 57, no. 12, pp. 4115-4125, 2010.

 [4] M. Seyedmahmoudian, S. Mekhilef, R. Rahmani, R. Yusof, and E. T. Renani, "Analytical modeling of partially shaded photovoltaic systems," Energies, vol. 6, no. 1, pp. 128-144, 2013. [5] H. Mortazavi, H. Mehrjerdi, M. Saad, S. Lefebvre, D. Asber, and L. Lenoir, "A Monitoring Technique for Reversed Power Flow Detection With High PV Penetration Level," IEEE Trans. Smart Grid, vol. 6, no. 5, pp. 2221-2232, 2015.

 

Real-Time Implementation of a Packed U-Cell Seven-Level Inverter with Low Switching Frequency Voltage Regulator

ABSTRACT:

 

In this paper a new cascaded nonlinear controller has been designed and implemented on the packed U-Cell (PUC) seven-level inverter. Proposed controller has been designed based on a simplified model of PUC inverter and consists of a voltage controller as outer loop and a current controller as inner loop. The outer loop regulates the PUC inverter capacitor voltage as the second DC bus. The inner loop is in charge of controlling the flowing current which is also used to charge and discharge that capacitor. The main goal of the whole system is to keep the DC capacitor voltage at a certain level results in generating a smooth and quasi-sine-wave 7-level voltage waveform at the output of the inverter with low switching frequency. The proposed controller performance is verified through experimental tests. Practical results prove the good dynamic performance of the controller in fixing the PUC capacitor voltage for various and variable load conditions and yet generating low harmonic 7-level voltage waveform to deliver power to the loads. Operation as an uninterruptible power supply (UPS) or AC loads interface for photovoltaic energy conversion applications is targeted.

KEYWORDS:

1.      Packed U-Cell

2.      Multilevel Inverter

3.      Voltage Balancing

4.      Nonlinear Controller

5.      Renewable energy conversion

 SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

In this paper a new cascaded nonlinear controller has been designed for 7-level PUC inverter based on the simple model derived by multilevel inverter topology concept. Experimental results showed appropriate dynamic performance of the proposed controller in stand-alone mode as UPS, renewable energy conversion system or motor drive applications. Different changes in the load and DC bus voltage have been made intentionally during the tests to challenge the controller

reaction in tracking the voltage and current references. Proposed controller demonstrated satisfying performance in fixing the capacitor voltage of the PUC inverter, generating seven-level voltage with low harmonic content at the output of the PUC inverter and ensures low switching frequency operation of those switches. By applying the designed controller on the 7-level PUC inverter it can be promised to have a multilevel converter with maximum voltage levels while using less active switches and DC sources aims at manufacturing a low-cost converter with high efficiency, low switching frequency, low power losses and also low harmonic contents without using any additional bulky filters

REFERENCES:

[1] H. Abu-Rub, M. Malinowski, and K. Al-Haddad, Power electronics for renewable energy systems, transportation and industrial applications: John Wiley & Sons, 2014.

[2] J. M. Carrasco, L. G. Franquelo, J. T. Bialasiewicz, E. Galván, R. P. Guisado, M. A. Prats, et al., "Power-electronic systems for the grid integration of renewable energy sources: A survey," IEEE Trans. Ind. Electron., vol. 53, no. 4, pp. 1002-1016, 2006.

[3] M. Mobarrez, M. G. Kashani, G. Chavan, and S. Bhattacharya, "A Novel Control Approach for Protection of Multi-Terminal VSC based HVDC Transmission System against DC Faults," in ECCE 2015- Energy Conversion Congress & Exposition, Canada, 2015, pp. 4208- 4213.

[4] B. Singh, A. Chandra, and K. Al-Haddad, Power Quality: Problems and Mitigation Techniques: John Wiley & Sons, 2014.

[5] 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, 1999