Development of Wind and Solar Based AC Microgrid with Power Quality Improvement for Local Nonlinear Load using MLMS

ABSTRACT:

 This work proposes a microgrid (μ-grid) integrating wind and solar photovoltaic (PV) resources, along with the battery energy storage (BES) to the three phase grid feeding the nonlinear load. The μ-grid disconcerted by probabilistic nonlinear time dependent parameters and their effects are compensated by cohesive controllers used for utility grid side voltage source converter (GVSC) and machine side VSC (MVSC). The switching controls and the reconfigurability of the μ-grid are addressed on imperative aspects of improving power quality (PQ), power reliability, nonlinear load compensation and economic utilization of resources. The nonlinear load compensation and PQ enhancement are achieved by executing modified version of the adaptive filtering technique including “momentum” based least mean square (MLMS) control technique, utilized for providing the switching control signals to the GVSC. It utilizes two preceding gradient weights for obtaining updated weight thereby improving the convergence rate and overcoming the limitation of conventional control of the same family. The MVSC acquires its switching signals from conventional vector control scheme and the encoderless estimation of speed and rotor position of the synchronous generator (SG) driven by wind turbine through back electromotive force control technique. The external environmental disturbances are overcome by utilizing perturb and observe (P&O) maximum power point (MPP) for wind optimal power extraction and adaptive P&O with variable perturbation step size for solar MPP estimation. Test results are obtained from the laboratory prototype under steady state and dynamic conditions including altering wind speed, intermittent solar insolation and variable load conditions. The PQ issues are addressed and investigated successfully.

KEYWORDS:

1.      Wind Power Generation

2.      Solar PV Power Generation

3.      AC Microgrid

4.      MLMS

5.      MPP and Power Quality

 SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

The proposed wind-solar AC microgrid has been designed and implemented to illustrate its improved PQ performance for local nonlinear load using MLMS adaptive control. The weight component and system performance using MLMS has been found with reduced oscillations. Effectiveness of the MLMS is realized through successful harmonic elimination, extraction of load current fundamental component with low static error and faster convergence rate. The wide range of wind speeds, solar insolation and load variations have been considered and the test results obtained from the prototype provide exceedingly well performance for the entire operational range. The grid current THD has been found well within the IEEE-519 harmonic standard. The proposed system has operated well under all the dynamic conditions as well as the power quality issues are mitigated satisfactorily.

 REFERENCES:

[1] R. Cuzner, “The socially responsible microgrid,” IEEE Electrif. Mag., vol. 6, no. 4, pp. 2-5, Dec. 2018.

[2] P. J. Chauhan, B. D. Reddy, S. Bhandari and S. K. Panda, “Battery energy storage for seamless transitions of wind generator in standalone microgrid,” IEEE Trans. Ind. Appl., vol. 55, no. 1, pp. 69-77, Jan.-Feb. 2019.

[3] M. Farhadi and O. Mohammed, “Energy storage technologies for high-power applications,” IEEE Trans. Ind. Appl., vol. 52, no. 3, pp. 1953-1961, May-June 2016.

[4] X. Hou, Y. Sun, J. Lu, X. Zhnag, L. H. Koh, M. Su and J. M. Guerrero, “Distributed hierarchical control of AC microgrid operating in grid-connected, islanded and their transition modes,” IEEE Access, vol. 6, pp. 77388-77401, 2018.

[5] S. Boudoudouh and M. Maaroufi, “Renewable energy sources integration and control in railway microgrid,” IEEE Trans. Ind. Appl., Early Access, 2019.

Detection of the faults in the photovoltaic array under normal and partial shading conditions

ABSTRACT:

This paper propounds a novel technique for detection of the faults in photovoltaic array by using Artificial Neural Network. By using a simulation model, the power variation under different faulty conditions such as open circuit fault, short circuit fault, and bridging fault are measured under normal and partial shading conditions. The simulated attributes are given to the Artificial Neural Network to predict the type of fault occurred in or between photovoltaic modules. Finally, three different training algorithms of Artificial Neural Network are compared for fault detection with help of mean square error as the performance parameter.

KEYWORDS:

1.      Fault detection

2.      Photovoltaic array

3.      Artificial neural network

4.      Open circuit fault

5.      Short circuit fault

6.      Bridging fault

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

In this paper, the fault detection method is proposed to detect the fault occurred in or between the PV modules. The performance of PV module has been investigated in this paper for different faults such as open circuit fault, short circuit fault and bridging fault under normal and partial shaded conditions. ANN is used to detect the faults occurred in or between PV modules under normal and partial shading conditions and it is tested with random inputs. Future work is to locating the fault in the large scale PV system.

REFERENCES:

[1] Liqun Liu, Xiaoli Meng and Chunxia Liu, “ A review of maximum power point tracking methods of PV power system at a uniform and partial shading”, International Journal on Renewable and Sustainable Energy Reviews, Vol.53, pp.1500-1507,2016.

[2] Kashif Ishaque and Zainal Salam, “ A review of maximum power point tracking techniques of PV system for uniform insolation and partial shading condition”, International Journal on Renewable and Sustainable Energy Reviews, Vol.19, pp.475-488,2013.

[3] M. Sabbaghpur Arani and M.A Hejazi, “ The comprehensive study of electrical faults in PV array”, Journal of Electrical and Computer Engineering, Volume 2016.

[4] S.Saravan and N.Ramesh Babu, “Maximum power point tracking algorithms for the photovoltaic system- A review”, International Journal on Renewable and Sustainable Energy Reviews, Vol.57, pp.192-204, 2016.

[5] K.L.Lian, J.H.Jhang, and I.S.Tian, “ A maximum power point tracking method based on perturb-and-observe combined with particle swarm optimization”, IEEE Journal of Photovoltaic, Vol.4, No.2,pp.626-633,2014.

Design and Modelling of a CSC Converter with a variable DC link voltage to drive a Brushless DC Motor Drive

ABSTRACT:

The applications based on Brushless DC motors are rapidly increasing in both industrial and domestic applications. This paper concerns the design, modeling, and analysis of canonical switching cell converter(CSCC) fed brushless DC motor. CSCC converter is one of the advanced converter topology offering a variable DC link voltage enabling it to suit a multitude of applications. MATLAB/Simulink is used to design and simulate the converter circuits. The modeled converter is employed to drive a BLDC motor and analyzed for different load conditions (Torque) and different DC link voltages to ensure the adaptability of the converter topology to suit a multitude of applications and conclusions has been drawn based on the analysis

KEYWORDS:

1.      BLDC motor

2.      DC-DC converters

3.      Canonical switching Cell converter

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

The paper presents the design procedure of 500-watt CSCC with a variable output voltage (70 V – 200V), along with a performance analysis of BLDC motor fed by the designed CSCC. The analysis goes with testing of the motor for various DC link voltage and load torque. The static and dynamic performance of the machine is presented along with the IAE, ITAE and ripple factor. The analysis of canonical switching cell converter fed brushless DC drives shows that the CSCC would be a better choice of front end converter to feed BLDC drive to accompt it in multitude of applications.

REFERENCES:

[1] B. Singh and S. Singh, “Single-phase power factor controller topologies for permanent magnet brushless DC motor drives,” IET Power Electronics, vol.3, no.2, pp.147- 175, March 2010.

[2] Chang Liang Xia, Permanent Magnet Brushless DC Motor Drives and Controls, Wiley Press, Beijing, 2012.

[3] P. Pillay and R. Krishnan, “Modeling of permanent magnet motor drives,” IEEE Trans. Ind. Elect., vol.35, no.4, pp.537-541, Nov 1988.

[4] M. A. Rahman and P. Zhou, “Analysis of brushless permanent magnet synchronous motors,” IEEE Trans. Ind. Elect., vol.43, no.2, pp.256-267, Apr 1996.

[5] Xiaoyan Huang, A. Goodman, C. Gerada, Youtong Fang and Qinfen Lu,“A Single Sided Matrix Converter Drive for a Brushless DC Motor in Aerospace Applications,” IEEE Trans. Ind. Elect., vol.59, no.9, pp.3542-3552, Sept. 2012.5                                                                                                                                                                                                                                                                                                                                                 

 

Application of Artificial Neural Networks for Shunt APF Control

ABSTRACT:  

Artificial Neural Network (ANN) is becoming an attractive estimation and regression technique in many control applications due to its parallel computing nature and high learning capability. There has been a lot of effort in employing the ANN in shunt active power filter (APF) control applications. Adaptive Linear Neuron (ADALINE) and feed-forward Multilayer Neural Network (MNN) are the most commonly used ANN techniques to extract fundamental and/or harmonic components present in the non-linear currents. This paper aims to provide an in-depth understanding on realizing ADALINE and feed-forward MNN based control algorithms for shunt APF. A step-by-step procedure to implement these ANN based techniques, in Matlab/ Simulink environment, is provided. Furthermore, a detailed analysis on the performance, limitation and advantages of both methods is presented in the paper. The study is supported by conducting both simulation and experimental validations.

KEYWORDS:

1.      Shunt APF

2.      ANN

3.      ADALINE

4.      Feed-forward MNN

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

In this paper, two widely used ANN based shunt APF control strategies, namely the ADALINE and feed-forward MNN, are investigated. A simple step by step procedure is provided to implement each method in Matlab/Simulink environment. The ADALINE is trained online by the LMS algorithm, while the MNN is trained offline using the SCG backpropagation algorithm to extract the fundamental load active current magnitude. The performance of these ANN based shunt APF controllers is evaluated through detailed simulation and experimental studies. Based on the study conducted in this paper, it is observed that the ADALINE based control technique performs better than the feed-forward MNN. For untrained load scenario, the feed-forward MNN fails to extract the fundamental component, resulting in overcompensation from the dc link PI regulator. On contrary, the online adaptiveness of ADALINE makes it applicable to any load condition.

REFERENCES:

[1] P. Kanjiya, V. Khadkikar, and H. H. Zeineldin, “A Noniterative Optimized Algorithm for Shunt Active Power Filter Under Distorted and Unbalanced Supply Voltages,” IEEE Trans. Ind. Electron., vol.60, no.12, pp.5376,5390, Dec. 2013.

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

[3] M. Popescu, A. Bitoleanu, and V. Suru, “A DSP-Based Implementation of the p-q Theory in Active Power Filtering Under Nonideal Voltage Conditions,” IEEE Trans. Ind. Informat., vol.9, no.2, pp.880,889, May 2013.

[4] V. Silva, J. G. Pinto, J. Cabral, J. L. Afonso, and A. Tavares, “Real time digital control system for a single-phase shunt active power filter,” in Conf. Rec. INDIN, 2012, pp.869,874.

[5] A. Hamadi, S. Rahmani, K. Al-Haddad, “Digital Control of a Shunt Hybrid Power Filter Adopting a Nonlinear Control Approach,” IEEE Trans. Ind. Informat., vol.9, no.4, pp.2092,2104, Nov. 2013. 

Coordination of SMES, SFCL and Distributed Generation Units for Micro-Grid Stability Enhancement via Wireless Communications

ABSTRACT:

To enhance the stability of a micro-grid under fault conditions, this paper proposes the coordination control of a superconducting magnetic energy storage (SMES), an active superconducting fault current limiter (SFCL), and distributed generation units via wireless network communications. This coordination control can smoothly separate the micro-grid from the main network in case of severe or permanent faults, and assist the micro-grid to achieve the fault ride-through (FRT) operation if the fault is minor or temporary. Details on the modeling, control strategy, and network architecture are presented. Moreover, the simulation analysis of a 10 kV class micro-grid including the SMES, SFCL, and photovoltaic generation units is implemented in MATLAB. Concerning the performance evaluation of the coordination control, not only severe and minor faults, but also different communication delays are taken into account. The results confirm the effectiveness of the proposed coordination control.

KEYWORDS:

1.      Coordination control

2.      Distributed generation

3.      Micro-grid

4.      Superconducting fault current limiter (SFCL)

5.      Superconducting magnetic energy storage (SMES)

6.      Wireless communications

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

In order to improve the stability of a micro-grid under short-circuit faults, this paper proposes and investigates the coordination of a SMES unit, an active SFCL, and multiple distributed generation units via the wireless communications. The severe and minor faults are considered, and the impacts of the wireless communication delay on the coordination performance are also studied. The results well demonstrate the effectiveness of the proposed coordination control, and it can maintain the power balance, accelerate the load recovery, suppress the PCC fault current, and mitigate the voltage-frequency fluctuation. Thus, the micro-grid’s transient performance is able to be enhanced considerably, and further the technical advantages of the SMES, active SFCL, distributed generation units and wireless communications can be fully utilized.

In the near future, the improvement of the coordination control will be carried out from multiple aspects, such as the parameter optimizations of the SMES and the SFCL, the robustness advancement of the wireless network, the suitableness enhancement of the coordination control for a large micro-grid/test system including several DG resources and control structures. In addition, the current coordination control does not consider the effects of the load dynamics on the transient performance of the micro-grid, and it means that just two static power loads are used. On the one hand, with regard to the necessity of introducing the load dynamics, it may closely depend on whether the current coordination control of the SMES, active SFCL and distributed generation units is enough to stabilize the micro-grid under the fault conditions. On the other hand, if more electrical devices take part in the coordination control, an intelligent coordination method based on multi-agent system technology can be properly applied. Related research results will be reported in later articles.

 REFERENCES:

 [1] Jae-young Yoon, Seung-ryul Lee, and In-tae Hwang, “A Quantitative Analysis on Future World Marketability of HTS Power Industry,” IEEE Trans. Smart Grid, vol. 4, no. 1, pp. 433–436, Feb. 2013.

[2] Jianwei Li, Qingqing Yang, Francis. Robinson, Fei Liang, Min Zhang, and Weijia Yuan, “Design and test of a new droop control algorithm for a SMES/battery hybrid energy storage system,” Energy, vol. 118, pp. 1110–1122, Jan. 2017.

[3] Meng Song, et al., “100 kJ/50 kW HTS SMES for Micro-Grid,” IEEE Trans. Appl. Superconduct., vol. 25, no. 3, June 2015, Art. ID. 5700506.

[4] Thai-Thanh Nguyen, et al., “Applying Model Predictive Control to SMES System in Microgrids for Eddy Current Losses Reduction,” IEEE Trans. Appl. Superconduct., vol. 26, no. 4, June 2016, Art. ID. 5400405.

[5] Lei Chen, et al., “Comparison of Superconducting Fault Current Limiter and Dynamic Voltage Restorer for LVRT Improvement of High Penetration Micro-Grid,” IEEE Trans. Appl. Superconduct., vol. 27, no. 4, June 2017, Art. ID. 3800607.

 

Control strategy of PMSG based wind energy conversion system under strong wind conditions

 ABSTRACT:

This paper presents a control approach for the Permanent Magnet Synchronous Generator (PMSG) based Wind Energy Conversion Systems (WECS) under a wide range of wind speeds. Generally, most of the wind turbines are turned-off and disconnected from the power grid, in case wind velocity is gone over 25 m/s. It may cause wind power supply shortage from wind farms. This research introduces a pitch angle controller as well as a rotational speed control system so that the PMSG based WECS can generate power if the wind speeds are above 25 m/s. The proposed method reduces the mechanical stress of the wind turbine by preferential reducing of the rotational speed rather than the mechanical torque during strong wind condition. As a result, the chance of turning-off the is reduced compared to the conventional control system because the PMSG based WECS can temporarily tolerate the wind speed up to 35 m/s. A 2 MW WECS with the electrical and mechanical characteristics is modeled in the MATLAB/Sim Power Systems® to verify the proposed research.

KEYWORDS:

1.      WECS

2.      PMSG

3.      Pitch angle control

4.      Strong wind conditions

SOFTWARE: MATLAB/SIMULINK

 CONCLUSION:

This paper describes a control method for the PMSG based WECS under strong wind conditions. Conventional control method is compared with the proposed control method considering same conditions and system parameters. In the MPPT control area, both conventional and proposed systems have shown similar performances. When the wind turbine is controlled at the rated power, the power fluctuation occurs with the conventional method. This is because, it is controlled by only the pitch angle control system with some delays. In the proposed method, both pitch angle and rotational speed control methods are designed for the wide-windrange of wind velocity. As a result, the output power is controlled with high accuracy by using the proposed method. In addition, the proposed method preferentially reduces the rotational speed rather than the mechanical torque in order to reduce the power coefficient and the centrifugal force during the strong wind conditions. For this reason, the allowable condition of power generation can temporarily reach up to the wind speed of 35 m/s. Therefore, it can be said that the PMSG based WECS with the proposed control method can avoid a sudden cut-off from the power grid during strong wind conditions as well as can continue to generate power in the typhoon prone area. However, if the wind speed goes above the 35 m/s the wind turbine needs to be shut down. In doing so it will give some time to bring appropriate load-frequency control action rather than sudden generation curtailment.

REFERENCES:

Aho, J., Buckspan, A., Laks, J., Fleming, P., Jeong, Y., Dunne, F., . . . . . . Johnson, K. (2012). A tutorial of wind turbine control for supporting grid frequency through active power control. 2012 American Control Conference (ACC). (pp. 3120–3131). https:// doi.org/10.1109/ACC.2012.6315180.

Ajami, A., Alizadeh, R., & Elmi, M. (2016). Design and control of a grid tied 6-switch converter for two independent low power wind energy resources based on pmsgs with mppt capability. Renewable Energy, 87(Part 1), 532–543. https://doi.org/10.  1016/j.renene.2015.10.031.

Bonfiglio, A., Delfino, F., Invernizzi, M., & Procopio, R. (2017). Modeling and maximum power point tracking control of wind generating units equipped with permanent magnet synchronous generators in presence of losses. Energies, 10(1), https://doi. org/10.3390/en10010102.

Cader, C., Bertheau, P., Blechinger, P., Huyskens, H., & Breyer, C. (2016). Global cost advantages of autonomous solar-battery-diesel systems compared to diesel-only systems. Energy for Sustainable Development, 31(Supplement C), 14–23. https:// doi.org/10.1016/j.esd.2015.12.007.

Chen, J., & Song, Y. (2016). Dynamic loads of variable-speed wind energy conversion system. IEEE Transactions on Industrial Electronics, 63(1), 178–188. https://doi.org/ 10.1109/TIE.2015.2464181

Control and energy management of a large scale grid-connected PV system for power quality improvement

 ABSTRACT:

Power quality is highlighted as an important parameter in modern power systems. Moreover, grid-connected photovoltaic power plants are increasing significantly in size and capacity. Elsewhere, due to the progressive integration of nonlinear loads in the grid, the principal role of a Solar Energy Conversion System (SECS) is not only to capture the maximum power from solar but, also to ensure some ancillary services and improve the quality of power. This paper presents a novel strategy dedicated to improve the management of active power generation, reactive power compensation and power quality of a SECS, while guaranteeing the possibility of exploiting the full capacity of the Power Conditioning System (PCS) and the PhotoVoltaic System (PVS). The proposed control algorithm is applied to a large scale PVS connected to the grid through a cascade of a DC-DC converter and a PWM inverter. This control strategy manages the SECS function’s priorities, between main active power generation, reactive power compensation and active filtering in such a way to guarantee a smooth and stable DC voltage and ensure a sinusoidal grid current. Top priority is given to the active power production over power quality improvement. Then, priority is given to reactive power compensation over mitigation of current harmonics absorbed by the non-linear load connected to the Point of Common Coupling (PCC). Moreover, the whole system upper limits of active and reactive powers have been determined in the (PQ) power plane on the basis of PVS available power, converters rated power and DC bus voltage smoothness and stability. Finally, a control procedure dedicated to the calculation of the inverter current commands is proposed in order to exploit the full capacity of the SECS and respect the determined power limits. Simulation results confirm the effectiveness and the performance of this control strategy and prove that the SECS can operate at its full power whilst the power quality can be improved by reactive power compensation and active filtering.

KEYWORDS:

1.      Power decoupled control

2.      Harmonic currents

3.      Power quality

4.      Active filtering

5.      Reactive power compensation

6.      SECS full power exploitation

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

In this paper, a novel strategy has been proposed to manage and improve the power quality of a grid connected large scale PVS. More accurately, fuzzy logic controllers have been used to guarantee a decoupled control of active and reactive powers injected into the grid. The PWM inverter is controlled in such a way to manage between active power production and power quality improvement without exceeding the whole system power capacity. The proposed priority control block gives top priority to active power production, then reactive power compensation and finally active filtering. The power capability of the whole system has been delimited in the (PQ) power plane (on the basis of the PVS available power, the power electronics converters rated power and the DC bus voltage smoothness and stability) and fully exploited without over-rating, by the calculation of an appropriate portion of current commands in order to ensure a better active filtering quality and keep the inverter current under its limit value corresponding to the whole system power capacity. Simulation results show the effectiveness and the performance of the proposed approach in terms of power generation, reactive power compensation and active filtering.

REFERENCES:

Ahmad, Z., Singh, S.N., 2018. Improved modulation strategy for single phase grid connected transformerless PV inverter topologies with reactive power generation capability. Sol. Energy 153, 356–375.

Aboudrar, I., El Hani, S., Mediouni, H., Bennis, N., Echchaachouai, A., 2017. Hybrid algorithm and active filtering dedicated to the optimization and the improvement of photovoltaic system connected to grid energy quality. Int. J. Renw. Energy Res. 7 (2), 894–900.

Arul Murugan, S., Anbarasan, A., 2014. Harmonics elimination in grid connected single phase PV inverter. In: Int. Conference on Engineering Technology and Science, Tamilnadu, India, 10–11 February 2014, (3) 1, pp. 1474–1480.

Albarracin, R., Alonso, M., 2013. Photovoltaic reactive power limits. In: 2013 12th IEEE Int. Conference Environ. Electr. Eng. Wroclaw, Poland, 5–8 May 2013, pp. 13–18.

Bhole, N., Shah Dr, P.J., 2017. Enhancement of power quality in grid connected photovoltaic system using predictive current control technique. Int. J. Rece. Innova. Trends in Compu. Communi 5 (7), 549–553.