A Direct Redundancy approach to Fault Tolerant Control of BLDC Motor with a damaged Hall-effect Sensor

 ABSTRACT:

 Often for closed loop operation of a Brushless direct current (BLDC) motor, Hall-effect sensors are used and recently theirs been a number of papers discussing Fault Tolerant Control (FTC) of the BLDC motor for a defective Hall-effect sensor. However, so far direct redundancy based approach for FTC of BLDC motor for a position sensor fault is not presented. This paper, contributes a direct redundancy based method by utilizing redundant Hall-effect sensors for FTC of BLDC motor. Redundant Hall-effect sensors generate additional transitions resulting in faster fault detection. To verify the proposed idea, Matlab/Simulink model is developed and the simulation results are presented by programing a Matlab function block acting as a fault tolerant controller. Furthermore, the algorithm is implemented into the MicroLabBox for experimental validation and the results are discussed.

KEYWORDS:

1.      Brushless machines

2.      Fault Tolerant Control

3.      Hall-effect devices

4.      Position measurement

5.       Signal Reconstruction

6.      Redundancy

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

Transitions of the redundant Hall-effect sensors provide supplementary opportunities to detect faults within electrical 30° or in worst case in electrical 45° and therefore the proposed FTC method results in faster fault compensation times as the experimental results show that the compensation is done in less than electrical 30°. Compared to other FTC methods that use Fourier coefficients and FFT calculations, requiring high end digital signal processors, this method offers less complexity, improved compensation time, and reduces the computational costs, however, use of direct redundancy does increase the system cost slightly. And furthermore, in recent research, for constant speed operation of BLDC motor, the Hall-effect sensor transitions are assumed to be equally spaced, however, experiments showed that transitions are not equally spaced, which makes implementation of the FTC process more complicated. To name a few reasons, there can be misaligned Hall-effect sensors, or cogging torque. Since the redundant sensor method presented here only considers the Hall-effect sensor signals, in that matter, the method presented in this paper offers robustness and simplicity.

REFERENCES:

[1]. J. Chiasson, Modeling and High-Performance Control of Electric Machines, Wiley-Interscience, 2005.

[2]. A. Tashakori and M. Ektesabi, "A simple fault tolerant control system for hall effect sensors failure of BLDC motor," in IEEE ICIEA, Melbourne, 2013.

[3]. Q. Zhang and M. Feng, "Combined commutation optimisation strategy for brushless DC motors with misaligned hall sensors," IET Electric Power Applications, vol. 12, no. 3, 2017.

[4]. X. Song, J. Fang and B. Han, "High-precision rotor position detection for high-speed surface PMSM drive based on linear hall-effect sensors," IEEE Transactions on Power Electronics, vol. 31, no. 7, July 2016.

[5]. S.-Y. Kim, C. Choi, K. Lee and W. Lee, "An improved rotor position estimation with vector-tracking observer in PMSM drives with low-resolution hall-effect sensors," IEEE Transactions on Industrial Electronics, vol. 58, no. 9, 2011.

 

A Commutation Torque Ripple Suppression Strategy for Brushless DC Motor Based on Diode-Assisted Buck-Boost Inverter

 ABSTRACT:

 

Based on diode-assisted buck-boost inverter, this paper proposes a new commutation torque ripple suppression strategy for brushless DC motor (BLDCM). Four types of switching vectors are constructed, according to the working pattern of the diode-assisted inverter and the operation mode of the BLDCM. Moreover, the effects of switching vector combination on commutation torque ripple suppression and motor speed regulation are analyzed in the commutation and normal conduction periods, respectively. Based on this analysis, the duration of switching vectors within each modulation cycle is derived and the sequence of vectors is arranged at the same time in these two periods. The proposed method can effectively suppress the commutation torque ripple over the full speed range by unified switching vectors during the commutation period, without needing to switch control strategies according to the speed range. In addition, the increase of the voltage stress of switching devices in the inverter bridge can be avoided by designing the duration and sequence of switching vectors during the commutation and normal conduction periods. The effectiveness of the presented method is validated by the experimental results.

KEYWORDS:

1.      Brushless DC motor

2.      Commutation torque ripple reduction

3.      Diode-assisted buck-boost inverter

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

In this paper, a new commutation torque ripple suppression strategy is proposed based on the diode-assisted boost-buck inverter. This strategy has the following advantages:

1) The proposed method can effectively improve the utilization of DC supply voltage, and it is promising for the industrial applications supplied by low-voltage DC source such as fuel cell, lithium battery, and photovoltaic array.

2) The commutation torque ripple over the full speed range can be suppressed effectively under the proposed method, without needing to switch control strategies according to the speed range.

3) By designing the duration and sequence of the large vector, small vector and zero vector, the increase of the voltage stress of switching devices in the inverter bridge can be avoided during the commutation and normal conduction periods.

4) Compared with the methods of adding a DC-DC converter, the proposed method can reduce the number of switches and passive devices, which is beneficial to reduce the cost of drive system.

REFERENCES:

[1] R. Krishnan, Permanent magnet synchronous and brushless DC motor drives[M]. CRC Press/Taylor & Francis, 2010.

[2] S. Chen, X. Zhou, G. Bai, K. Wang, et al, “Adaptive commutation error compensation strategy based on a flux linkage function for sensorless brushless DC motor drives in a wide speed range,” IEEE Trans. Power Electron., vol. 33, no. 5, pp. 3752–3764, May. 2018.

[3] A. Lee, C. Fan, and G. Chen, “Current integral method for fine commutation tuning of sensorless brushless DC motor,” IEEE Trans. Power Electron., vol. 32, no.12, pp. 9249–9266, Dec. 2017.

[4] Y. Shen and Z. Q. Zhu, “Investigation of permanent magnet brushless machines having unequal-magnet height pole,” IEEE Trans. Magn., vol. 48, no. 12, pp. 4815–4830, Dec. 2012.

[5] W. Jiang, Y. Liao, J. Wang, and Y. Xie, “Improved control of BLDCM considering commutation torque ripple and commutation time in full speed range,” IEEE Trans. Power Electron., vol. 33, no.5, pp. 4249–4260, May. 2018.

A Novel V2V Charging Method Addressing the Last Mile Connectivity

 ABSTRACT

One of the main drawbacks in adopting EV vehicles is the last mile connectivity issue. There is always a chance that the user/rider may get stranded without EV charge and no EV charging stations nearby. With the aim of solving such an exigency, this paper proposes a novel V2V charging technique which allows charge transfer between two EVs off the grid, and discusses its modes of operation. Non-isolated bidirectional DC-DC converters with average current control technique are simulated in a MATLAB/Simulink environment to verify and validate the efficiency and charging time for the proposed charging technique.

KEYWORDS

1.      V2V charging

2.      Bi-directional converter

3.      Pricing strategy

SOFTWARE: MATLAB/SIMULINK

CONCLUSION

A V2V charging scheme is proposed to synchronize the charging between two electric vehicles. This is particularly needed when an EV user is left stranded without battery charge and with no access to EV charging station. In this scenario, the proposed model allows another EV user to assist the stranded EV by charging from his EV thus solving last mile connectivity issues. The proposed model consists of a dual converter in the electric vehicle which enables fast DC charging or discharging. Extensive MATLAB simulation results on the model proves that the proposed work is capable of charging an EV from another under average current control method. The efficiency, SOC status and charging time for the proposed method is also analyzed. From the analysis it is evident that as the SOC difference increases the efficiency obtained also increases. To reduce the charging time and to enhance the efficiency average current control method is simulated and analyzed. The results obtained are presented and the results confirm the effectiveness of the proposed work. V2V energy transfers which were reported in the earlier literature uses the concept of connected ad-hoc networks present in parking lots etc., where the vehicles parked in the parking lot are used for energy transfer through a connected bus in the parking lot itself. The term ‘novel’ has been used here as the issue of EV being left stranded without battery charge and with no access to charging station is not addressed anywhere in the literature and also the technique of using cascaded bi-directional converters for charging one vehicle from the other vehicle adds novelty to the V2V energy transfer. Cascaded Bidirectional converters can even facilitate the charge transfer when the electric vehicles battery voltage levels are different, that’s why cascaded converters has been employed.

REFERENCES

[1] Markel, T., Saxena. S, Kahl. K, Pratt. R, "Multi-Lab EV Smart Grid Integration Requirements Study: Providing Guidance on Technology Development and Demonstration", National Renewable Energy Laboratory. Retrieved 2016-03-08, 2005.

[2] Liu, Wei-Shih, Jiann-Fuh Chen, Tsorng-Juu Liang, Ray-Lee Lin, and Ching-Hsiung Liu, “Analysis, design, and control of bidirectional cascaded configuration for a fuel cell hybrid power system," IEEE Transactions on Power Electronics 25,Vol. 6, 2010, pp no:- 1565-1575.

[3] Akshya, S., Anjali Ravindran, A. Sakthi Srinidhi, Subham Panda, and Anu G. Kumar, "Grid integration for electric vehicle and photovoltaic panel for a smart home." 2017 International Conference on Circuit, Power and Computing Technologies (ICCPCT), pp. 1-8, 2017.

[4] Nagar, Ishan, M. Rajesh, and P. V. Manitha, “A low cost energy usage recording and billing system for electric vehicle,” International Conference on Inventive Communication and Computational Technologies (ICICCT), pp. 382-384, 2017.

[5] Rajalakshmi, B., U. Soumya, and Anu G. Kumar. “Vehicle to grid bidirectional energy transfer: Grid synchronization using Hysteresis Current Control”, International Conference on Circuit, Power and Computing Technologies (ICCPCT), pp. 1-6, 2017.

Wind Energy Fed UPQC System for Power Quality Improvement

 ABSTRACT

The extensive use of non-linear loads in domestic, industrial and commercial services origin harmonic complications. Harmonics make malfunctions in profound equipment, voltage drop across the network, conductor heat increases and overvoltage through resonance. All these problems can be remunerated by using Unified Power Quality Controller (UPQC) and the operation of UPQC depends upon the available voltage across capacitor present in dc link. If the capacitor voltage is maintained constant then it gives satisfactory performance. The proposed research is basically on designing of Wind energy fed to the dc link capacitor of UPQC so as to maintain proper voltage across it and operate the UPQC for power quality analysis. The proposed technique is the grouping of shunt and series Active Power Filter (APF) to form UPQC which is fed wind energy system and connected to grid for better response in the output. In this paper, the simulation model of series APF, shunt APF, UPQC and Wind energy with UPQC are design in Matlab. The proposed Wind energy-UPQC is design in Matlab simulation for reduction of voltage sag, swell, harmonics in load current and compensation of active and reactive power.

KEYWORDS

1.      Harmonics

2.      Power quality

3.      Unified power quality conditioner

      Wind energy

SOFTWARE: MATLAB/SIMULINK

 CONCLUSION

The advantage of wind energy system is to retain a constant voltage of 600 volts across the DC-Link capacitor. In this work the wind energy with boost converter output is 600V and simulation of wind energy-UPQC maintains constant voltage of 600V when Sag, Swell and Interruption occur. It also reduces the harmonics content to 2.33% if any nonlinear load is associated as shown in Figure 19. Hence the proposed scheme can regulate active and reactive power injection to the grid and compensate voltage sag and swell in addition to the other usual operation of UPQC effectible as the voltage across the dc link capacitor is maintained constant. Figure 20 shows DC link voltage.

REFERENCES

[1] Carrasco JM, Franquelo LG, Bialasiewicz JT, Galván E, PortilloGuisado RC, Prats MM, León JI, Moreno-Alfonso N. Power-electronic systems for the grid integration of renewable energy sources: A survey. IEEE Transactions on industrial electronics. 2006; 53(4): 1002-1016.

[2] Samal S, Hota PK. Power Quality Improvement by Solar Photo-voltaic/Wind Energy Integrated System Using Unified Power Quality Conditioner. International Journal of Power Electronics and Drive Systems (IJPEDS). 2017; 8(3): 1424.

[3] Samal S, Hota PK. Power Quality Improvement by Solar Photo-voltaic/Fuel Cell Integrated System Using Unified Power Quality Conditioner. International Journal of Renewable Energy Research (IJRER). 2017; 7(4): 2075-84.

[4] Samal S, Hota PK. Design and analysis of solar PV-fuel cell and wind energy based microgrid system for power quality improvement. Cogent Engineering. 2017; 4(1): 1402453.

[5] Basu M, Das SP, Dubey GK. Comparative evaluation of two models of UPQC for suitable interface to enhance power quality. Electric Power Systems Research. 2007; 77(7): 821-830.

 

Fuzzy Sliding Mode Control for Photovoltaic System

 ABSTRACT

In this study, a fuzzy sliding mode control (FSMC) based maximum power point tracking strategy has been applied for photovoltaic (PV) system. The key idea of the proposed technique is to combine the performances of the fuzzy logic and the sliding mode control in order to improve the generated power for a given set of climatic conditions. Different from traditional sliding mode control, the developed FSMC integrates two parts. The first part uses a fuzzy logic controller with two inputs and 25 rules as an equivalent controller while the second part is designed for an online adjusting of the switching controller’s gain using a fuzzy tuner with one input and one output. Simulation results showed the effectiveness of the proposed approach achieving maximum power point. The fuzzy sliding mode (FSM) controller takes less time to track the maximum power point, reduced the oscillation around the operating point and also removed the chattering phenomena that could lead to decrease the efficiency of the photovoltaic system.

KEYWORDS

1.      DC-DC converter

2.      Fuzzy sliding mode control

3.      photovoltaic system

4.      MPPT

5.      Solar energy

SOFTWARE: MATLAB/SIMULINK

 CONCLUSION

In this paper, a fuzzy sliding mode controller based MPPT technique was developed and tested. The proposed controller is designed by combining the fuzzy logic and sliding mode control to guarantee the stability and the tracking performance and also to avoid the drawbacks of the traditional SM and FL controllers. A Matlab/Simulink based simulation of a stand-alone PV system under varying climatic conditions and two levels of load was carried out to validate the proposed controller. Simulation results demonstrate that the designed FSMC-MPPT exhibits good responses as it successfully and accurately achieved the maximum power point with a significantly higher performance than the P&O, SM and FLC strategies. The proposed approach provides a feasible approach to control PV power systems.

REFERENCES

[1] Dounis, A.I., Kofinas, P., Alafodimos, C., &Tseles, D. (2013). Adaptive fuzzy gain scheduling PID controller for maximum power point tracking of photovoltaic system. Renewable energy, 60, 202-214.

[2] Bhatnagar, P., & Nema, R.K. (2013). Maximum power point tracking control techniques: State-of-the-art in photovoltaic applications. Renewable and Sustainable Energy Reviews, 23, 224-241.

[3] Farhat, M., Barambones, O., & Sbita, L. (2015). Efficiency optimization of a DSP-based standalone PV system using a stable single input fuzzy logic controller. Renewable and Sustainable Energy Reviews, 49, 907-920.

[4] Kalashani, Mostafa Barzegar et Farsadi, Murtaza. New Structure for Photovoltaic Systems with Maximum Power Point Tracking Ability. International Journal of Power Electronics and Drive Systems, 2014, vol. 4, no 4, p. 489.

[5] Liu, F., Kang, Y., Zhang, Y., & Duan, S. (2008, June). Comparison of P&O and hill climbing MPPT methods for grid-connected PV converter. In Industrial Electronics and Applications, 2008. ICIEA 2008. 3rd IEEE Conference on (pp. 804-807). IEEE.

A modified PV-wind-PEMFCS-based hybrid UPQC system with combined DVR/STATCOM operation by harmonic compensation

ABSTRACT

This paper describes an improved Flexible Alternating Current Transmission System (FACTS)-based custom power controller with dynamic voltage restorer (DVR), static compensator (STATCOM) and unified power quality conditioner (UPQC) topology. The proposed controller can feed the power to grid and proficiently moderate the power quality problems like sag, swell, flicker, voltage interruption, reactive and active power compensation and voltage disturbances with harmonic problems to make sure power quality in the distribution system. The proposed configuration utilizes the Distributed generations (DGs), e.g. Photovoltaic (PV), wind and proton exchange membrane fuel cell stack connected to the micro-grid for realilazisation of DVR, STATCOM and UPQC operation with reduced filtering requirements. Space vector pulse width modulation -based hybrid cascade bottom leg multilevel inverter has been used for this purpose. The proposed topology has been simulated using MATLAB/Simulink and validated experimentally on a practical system. It is shown that the UPQC performs significantly better than the DVR and STATCOM for the improvement of different power quality issues.

KEYWORDS

1.      Hybrid cascade bottom leg multilevel inverter

2.      Dynamic voltage restorer

3.      Static compensator

4.      Unified power quality conditioner

5.      Space vector pulse width modulation

6.      Proton exchange membrane fuel cell stack

7.      Power quality

SOFTWARE: MATLAB/SIMULINK

CONCLUSION

This paper investigates the combined renewable sources of PV-wind-PEMFCS-DVR, PV-wind-PEMFCSSTATCOM and PV-wind-PEMFCS-UPQC system for the purpose of simultaneous compensation and active power injection. This proposed method is capable to compensate network power quality issues and mitigate their effects on sensitive loads in distribution power systems. The simulation and hardware outcomes specify the capability of custom power device in mitigating the voltage variation and harmonic polluting loads. The output voltage harmonics is reduced by SVPWM switching for the operation of DVR, STATCOM or UPQC modes. The proposed system also decreases the overall voltage THD in the micro-grid, decreases the total system loss, improves the dc link voltage, increases the effecting speed, solves the loss of commutation, minimizes the harmonics and optimizes the highfrequency switching problems. The proposed method is simple and can be easily implemented with the help of already available drive compatible hardware.

REFERENCES

[1] Kadri R, Andrer H, Gaubert J-P, et al. Modeling of the photovoltaic cell circuit parameters for optimum connection model and real-time emulator with partial shadow conditions. Energy. 2012 Jun;42(1):57–67. Available from: https://doi.org/10.1016/j.energy.2011. 10.018

[2] Bouilouta A, Mellit A, Kalogirou SA. New MPPT method for stand-alone photovoltaic systems operating under partially shaded conditions. Energy. 2013;55:1172–1185.

[3] Rahim KNA, Ping HW, Selvaraj J. Photovoltaic module modeling using simulink/matlab. Procedia Environ Sci. 2013;17:537–546.

[4] Dali M, Belhadj J, Roboam X. Hybrid solar-wind system with battery storage operating in grid-connected and standalone mode: control and energy managementexperimental investigation. Energy. 2010;35:2587– 2595.

[5] Bollen M. Understanding power quality problems: voltage sag and interruptions. New York: IEEE Press; 1999.

The Fastest MPPT Tracking Algorithm for a PV array fed BLDC Motor Driven Air Conditioning system

 ABSTRACT:

The fastest and novel adaptive voltage reference MPPT tracking algorithm for PV cluster sustained BLDC drive for aerating and cooling application is proposed in this paper. The fastest maximum power point tracking (MPPT) algorithm tracks the power instantaneously if there is any change in the solar irradiation. Low cost and energy efficiency is achieved by removing the conventional DC/DC boost converter stage which reduces the switching losses and further reduces the overall cost of the system thereby minimizing the power conversion stages. The proposed quickest MPPT algorithm for BLDC motor driven PV array fed air conditioning system is designed and modelled such that the performance is not affected even under the dynamic conditions. The proposed system is validated by simulation studies.

KEYWORDS:

1.      Instantaneous

2.      Low cost

3.      Efficient

4.      MPPT

5.      BLDC

6.      Air conditioner compressor

 SOFTWARE: MATLAB/SIMULINK

 CONCLUSION:

In this study, a novel adaptive constant voltage reference MPPT technique was proposed to extort maximum power from solar panels and simultaneously uses PV voltage and current deviations to track the Maximum power point of a PV array under varying irradiance conditions has been presented in this paper. The fastest MPPT algorithm is simulated and discussed to extract maximum power from solar panels without using DC-DC converters thereby reducing switching losses which in turn increasesr efficiency and reduces the cost for PV array fed BLDC Motor driven air conditioning system. The MATLAB simulation results effectively exhibit that, the proposed adaptive constant voltage MPPT algorithm works fine and shows good dynamic and steady state performance.

REFERENCES:

[1] Rodrigo A. Gonzalez, Marcelo A. Perez, Hugues Renaudineau and Freddy Flores-Bahamonde, “Fast Maximum Power Point Tracking Algorithm based on Switching Signals Modification,” IEEE International Conference on Compatibility, Power Electronics and Power Engineering (CPE-POWERENG), pp. 448-453, 4-6 April 2017.

[2] Hassan Fathabadi, “Novel fast dynamic MPPT (maximum power point tracking) technique with the capability of very high accurate power tracking,”Elsevier journal Energy., Vol. 94, pp. 466-475, Jan. 2016.

[3] E. Mamarelis, G. Petrone and G. Spagnuolo, “Capacitor Peak Current Control for MPPT Photovoltaic Applications,” 39th Annual Conference of the IEEE Industrial Electronics Society, pp. 3347–3352, Nov 2013.

[4] Arash Kalantari , A.Rahmati and A.Abrishamifar, “A Faster Maximum Power Point Tracker Using Peak Current Control,” IEEE Symposium on Industrial Electronics and Applications, pp. 117–122, October 4-6, 2009.

[5] Neil S. D'Souza, Luiz A. C. Lopes, and Xuejun Liu, “Peak Current Control Based Maximum Power Point Trackers For Faster Transient Responses,” Canadian Conference on Electrical and Computer Engineering on 7-10 May 2006.