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Recent advancements in renewable energy have made it possible to meet the load demand on the grid by utilizing smaller distributed renewable energy resources. However, advanced control techniques are required to eliminate the potential of instabilities caused due to load demand variation, as well as the power generation fluctuations by these renewable sources. Due to intermittent nature of renewable sources, a distributed average-based control is presented with a communication network within small-scale distributed grids with improved DC microgrid (MG) control resilience. Global reference set point is achieved using an average-based estimated correction term by utilizing the communication network structure to converge all the agent nodes to a common agreement. Any link failure or latencies in the communication network may disturb the load balance within generating and load agent nodes of the DC MG. The proposed distributed FIR based filter secondary control aims to improve the resilience of the DC MG control by achieving load sharing and voltage regulation, keeping the main conventional control system unaffected by communication link islanding. The effectiveness of the proposed control scheme is substantiated through a detailed study comparing it with existing conventional techniques by presenting mathematical model and experimental simulation results using MATLAB/Simpower tool.
Muhammad Umair Shahid; Muhammad Mansoor Khan; Khurram Hashmi; Muhammad Talib Faiz; Imad Hussain; Ji Liang; HouJun Tang. A distributed average-based enhanced resilient control for sustainable energy DC microgrids. Electric Power Systems Research 2020, 186, 106420 .
AMA StyleMuhammad Umair Shahid, Muhammad Mansoor Khan, Khurram Hashmi, Muhammad Talib Faiz, Imad Hussain, Ji Liang, HouJun Tang. A distributed average-based enhanced resilient control for sustainable energy DC microgrids. Electric Power Systems Research. 2020; 186 ():106420.
Chicago/Turabian StyleMuhammad Umair Shahid; Muhammad Mansoor Khan; Khurram Hashmi; Muhammad Talib Faiz; Imad Hussain; Ji Liang; HouJun Tang. 2020. "A distributed average-based enhanced resilient control for sustainable energy DC microgrids." Electric Power Systems Research 186, no. : 106420.
The cross-coupling effect between the induction coils of a multiple-receiver wireless power transfer (MRWPT) system severely weakens its overall performance. In this paper, a time-sharing control strategy for MRWPT systems is proposed to reduce the cross-coupling between receiver coils. An active-bridge rectifier is introduced to the receivers to replace the uncontrollable rectifier to achieve synchronization of the time-sharing control. The synchronization signal generated by an active-bridge rectifier can be directly used to realize the synchronization of time-sharing control and hence saved the traditional zero-crossing point detection circuits for time-sharing circuits. Moreover, the proposed time-sharing system has the advantages of both operating under a resistance-matching condition and providing target output voltage for each receiver. Furthermore, a voltage control strategy was developed to provide both high efficiency and a target output voltage for each receiver. Finally, the simulation and experimental results show that the time-sharing MRWPT system reduced the cross-coupling effect between the receiver coils, and the voltage control strategy provided both a high efficiency and a target output voltage for each receiver.
Weikun Cai; Dianguang Ma; Xiaoyang Lai; Khurram Hashmi; HouJun Tang; Junzhong Xu. Time-Sharing Control Strategy for Multiple-Receiver Wireless Power Transfer Systems. Energies 2020, 13, 599 .
AMA StyleWeikun Cai, Dianguang Ma, Xiaoyang Lai, Khurram Hashmi, HouJun Tang, Junzhong Xu. Time-Sharing Control Strategy for Multiple-Receiver Wireless Power Transfer Systems. Energies. 2020; 13 (3):599.
Chicago/Turabian StyleWeikun Cai; Dianguang Ma; Xiaoyang Lai; Khurram Hashmi; HouJun Tang; Junzhong Xu. 2020. "Time-Sharing Control Strategy for Multiple-Receiver Wireless Power Transfer Systems." Energies 13, no. 3: 599.
For high-power single-transmitter single-receiver wireless power transfer (STSRWPT) systems, the coils suffer from high voltage and current stresses. With increased power requirements, the coils become bottlenecks for power flow. To increase the power level, multiple-transmitter multiple-receiver wireless power transfer (MTMRWPT) systems with parallel circuits are developed that reduce the voltage and current stresses on the coils and improve power-handling capability. Firstly, an improved current distribution (ICD) control strategy is developed to simultaneously achieve high transfer efficiency, balanced current distribution and constant output voltage. Secondly, it is further shown that the ICD control strategy has the advantage that the currents at the transmitter coils are balanced and it reduces the control complexity simultaneously. Thirdly, an asynchronous particle swarm optimization (APSO) algorithm is applied to the ICD control strategy to verify the feasibility of the proposed control strategy. Lastly, a two-transmitter two-receiver wireless power transfer (WPT) system based on the ICD control strategy is proved to obtain an efficiency of more than 89.1% and provides the target output voltage 20 V with balanced current distribution.
Weikun Cai; Xiaoyang Lai; Dianguang Ma; HouJun Tang; Khurram Hashmi; Junzhong Xu. Management of Multiple-Transmitter Multiple-Receiver Wireless Power Transfer Systems Using Improved Current Distribution Control Strategy. Electronics 2019, 8, 1160 .
AMA StyleWeikun Cai, Xiaoyang Lai, Dianguang Ma, HouJun Tang, Khurram Hashmi, Junzhong Xu. Management of Multiple-Transmitter Multiple-Receiver Wireless Power Transfer Systems Using Improved Current Distribution Control Strategy. Electronics. 2019; 8 (10):1160.
Chicago/Turabian StyleWeikun Cai; Xiaoyang Lai; Dianguang Ma; HouJun Tang; Khurram Hashmi; Junzhong Xu. 2019. "Management of Multiple-Transmitter Multiple-Receiver Wireless Power Transfer Systems Using Improved Current Distribution Control Strategy." Electronics 8, no. 10: 1160.
Autonomous, self-governing micro energy networks are a smart energy solution that satisfy the energy needs of isolated communities. Such smart micro networks usually comprise of several distributed semi-controllable power resources, storages and loads. Usually, the power generation sources draw their energy from renewable energy resources. Power electronics converters suitably condition the power to be transmitted and utilized. A sensory, control and communication layer ensures the integration of several network components to achieve stable network operation. Distributed power-sharing methods function at local processing and decision-making nodes across the energy network. The complete control scheme is a hierarchical structure divided into four control levels. Faults and latencies experienced at the communication network layer adversely affect the performance of the control scheme. This paper proposes a new and improved hierarchical, multi-agents-based control strategy for efficient power-sharing, voltage and frequency regulation between nodes during communication link latencies. A novel distributed averaging estimator is proposed to estimate power injected in the system at various nodes and thereby mitigate the effect of relayed information delays. The effectiveness of the proposed strategy is established comprehensively through mathematical modeling, analytical proofs, discrete-time small signal stability analysis, and MATLAB case study simulations.
Khurram Hashmi; Muhammad Mansoor Khan; Muhammad Umair Shahid; Arshad Nawaz; Asad Khan; Jia Jun; HouJun Tang. An energy sharing scheme based on distributed average value estimations for islanded AC microgrids. International Journal of Electrical Power & Energy Systems 2019, 116, 105587 .
AMA StyleKhurram Hashmi, Muhammad Mansoor Khan, Muhammad Umair Shahid, Arshad Nawaz, Asad Khan, Jia Jun, HouJun Tang. An energy sharing scheme based on distributed average value estimations for islanded AC microgrids. International Journal of Electrical Power & Energy Systems. 2019; 116 ():105587.
Chicago/Turabian StyleKhurram Hashmi; Muhammad Mansoor Khan; Muhammad Umair Shahid; Arshad Nawaz; Asad Khan; Jia Jun; HouJun Tang. 2019. "An energy sharing scheme based on distributed average value estimations for islanded AC microgrids." International Journal of Electrical Power & Energy Systems 116, no. : 105587.
Self-governed micro power networks are a promising solution for meeting the energy needs of isolated communities not having access to regular transmission networks. The control of such isolated networks requires regulation and “fair” sharing of several power generation and storage resources as well as efficient peer-to-peer coordination between power converters operating in the network. The regulation of key parameters as voltage, frequency and power sharing is to be ensured for the system to operate optimally. This paper proposes a new, de-centralized, and hierarchical control approach for power inverters in isolated micro networks with multi-layered controls, each addressing the regulation of key system parameters. The proposed scheme uses distributed quasi-averaging estimators at each participating node to achieve resilience towards disturbances caused by delayed transmission of measurement and control signals in the data acquisition and information exchange layer. Detailed system models are developed using MATLAB and Sim-power systems to test the effectiveness of the proposed scheme under varying control and network scenarios. The results of these studies are presented as pole zero evolutions, stability margins and case study wise simulations. The studies carried out verify the validity of the proposed control strategy for micro-distribution networks.
Khurram Hashmi; Muhammad Mansoor Khan; Jianming Xu; Muhammad Umair Shahid; Salman Habib; Muhammad Talib Faiz; HouJun Tang. A Quasi-Average Estimation Aided Hierarchical Control Scheme for Power Electronics-Based Islanded Microgrids. Electronics 2019, 8, 39 .
AMA StyleKhurram Hashmi, Muhammad Mansoor Khan, Jianming Xu, Muhammad Umair Shahid, Salman Habib, Muhammad Talib Faiz, HouJun Tang. A Quasi-Average Estimation Aided Hierarchical Control Scheme for Power Electronics-Based Islanded Microgrids. Electronics. 2019; 8 (1):39.
Chicago/Turabian StyleKhurram Hashmi; Muhammad Mansoor Khan; Jianming Xu; Muhammad Umair Shahid; Salman Habib; Muhammad Talib Faiz; HouJun Tang. 2019. "A Quasi-Average Estimation Aided Hierarchical Control Scheme for Power Electronics-Based Islanded Microgrids." Electronics 8, no. 1: 39.
The monitoring and control of renewable energy sources (RESs) based on DC (Direct Current) microgrids (DC MG) are gaining much consideration at this time. In comparison with the isolated individual control of converters in a microgrid, DC microgrids provide better voltage regulation and harmonized energy generation/consumption. To address the inherent vulnerability of communication links, robust methods have been proposed that improve the resilience of communication-based control. However, the failure of the communication links in microgrid control layers remains a considerable issue that may lead to one or more nodes being disconnected and operating as a communication island. Such types of communication islanding may cause the unpredictable behavior of the system and further destabilization may lead to a cascaded failure. This paper proposes a fast algorithm to detect and evaluate network connectivity based on the information stored at every node in the form of a look-up table. The control structure has been modified under communication islanding, and a communication connectivity observer is used at every node to detect and address power flow issues under communication islanding. The proposed method has been verified through mathematical analysis, simulation, and experimental results.
Muhammad Umair Shahid; Muhammad Mansoor Khan; Jianming Xu; Khurram Hashmi; Salman Habib; Muhammad Adnan Mumtaz; HouJun Tang. A Hierarchical Control Methodology for Renewable DC Microgrids Supporting a Variable Communication Network Health. Electronics 2018, 7, 418 .
AMA StyleMuhammad Umair Shahid, Muhammad Mansoor Khan, Jianming Xu, Khurram Hashmi, Salman Habib, Muhammad Adnan Mumtaz, HouJun Tang. A Hierarchical Control Methodology for Renewable DC Microgrids Supporting a Variable Communication Network Health. Electronics. 2018; 7 (12):418.
Chicago/Turabian StyleMuhammad Umair Shahid; Muhammad Mansoor Khan; Jianming Xu; Khurram Hashmi; Salman Habib; Muhammad Adnan Mumtaz; HouJun Tang. 2018. "A Hierarchical Control Methodology for Renewable DC Microgrids Supporting a Variable Communication Network Health." Electronics 7, no. 12: 418.
Recently, wireless power transfer (WPT) systems with active receivers have been proposed for conduction loss reduction, bidirectional power transfer and efficiency improvement. However, the synchronization of WPT systems is complex in nature with the selection of high operating frequencies. Without proper synchronization, power oscillations appear and the system can become unstable. In this paper, a detailed analysis of different WPT systems is presented and the essence of the synchronization technique is derived as being composed of two functions: independent frequency locking and reference phase calibration. The voltage across the receiver-side compensation capacitor is divided and utilized for frequency locking, whereas the reference phase calibration is realized through software code. The proposed method is effective and easy to implement, with a lower overall cost due to its simplicity. The technique can work effectively at high frequency and withstand large variations of operating frequency, load and mutual inductance. In addition, it can address the synchronization problem of multiple active receiver WPT systems with and without cross coupling among the receiving coils. Theoretical analysis and experimental results validate the proposed technique.
Xin Liu; Nan Jin; Xijun Yang; Tianfeng Wang; Khurram Hashmi; HouJun Tang. A Novel Synchronization Technique for Wireless Power Transfer Systems. Electronics 2018, 7, 319 .
AMA StyleXin Liu, Nan Jin, Xijun Yang, Tianfeng Wang, Khurram Hashmi, HouJun Tang. A Novel Synchronization Technique for Wireless Power Transfer Systems. Electronics. 2018; 7 (11):319.
Chicago/Turabian StyleXin Liu; Nan Jin; Xijun Yang; Tianfeng Wang; Khurram Hashmi; HouJun Tang. 2018. "A Novel Synchronization Technique for Wireless Power Transfer Systems." Electronics 7, no. 11: 319.
Battery charging is a fundamental application of Wireless Power Transfer (WPT) systems that requires effective implementation of Constant Current (CC) and Constant Voltage (CV) power conduction modes. DC-DC converters used in WPT systems utilize large inductors and capacitors that increase the size and volume of the system in addition to causing higher DC losses. This work proposes a novel single-switch active rectifier for phase controlled WPT systems that is smaller in volume and weight as compared to conventional WPT topologies. The proposed method simplifies the control scheme using improved Digital Phase Control (DPC) and Analog Phase Control (APC) to realize the CC and CV power transfer modes. Furthermore, it prevents forward voltage losses in Silicon Carbide (SiC) switches and shoot through states with improved switching patterns. Simulation studies and experimental results are added to verify the effectiveness of the proposed methodology.
Xin Liu; Nan Jin; Xijun Yang; Khurram Hashmi; Dianguan Ma; HouJun Tang. A Novel Single-switch Phase Controlled Wireless Power Transfer System. Electronics 2018, 7, 281 .
AMA StyleXin Liu, Nan Jin, Xijun Yang, Khurram Hashmi, Dianguan Ma, HouJun Tang. A Novel Single-switch Phase Controlled Wireless Power Transfer System. Electronics. 2018; 7 (11):281.
Chicago/Turabian StyleXin Liu; Nan Jin; Xijun Yang; Khurram Hashmi; Dianguan Ma; HouJun Tang. 2018. "A Novel Single-switch Phase Controlled Wireless Power Transfer System." Electronics 7, no. 11: 281.
This paper presents a comparative analysis of a new topology based on an asymmetric hybrid modular multilevel converter (AHMMC) with recently proposed multilevel converter topologies. The analysis is based on various parameters for medium voltage-high power electric traction system. Among recently proposed topologies, few converters have been analysed through simulation results. In addition, the study investigates AHMMC converter which is a cascade arrangement of H-bridge with five-level cascaded converter module (FCCM) in more detail. The key features of the proposed AHMMC includes: reduced switch losses by minimizing the switching frequency as well as the components count, and improved power factor with minimum harmonic distortion. Extensive simulation results and low voltage laboratory prototype validates the working principle of the proposed converter topology. Furthermore, the paper concludes with the comparison factors evaluation of the discussed converter topologies for medium voltage traction applications.
Muhammad Ali; Muhammad Mansoor Khan; Jianming Xu; Muhammad Talib Faiz; Yaqoob Ali; Khurram Hashmi; HouJun Tang. Series Active Filter Design Based on Asymmetric Hybrid Modular Multilevel Converter for Traction System. Electronics 2018, 7, 134 .
AMA StyleMuhammad Ali, Muhammad Mansoor Khan, Jianming Xu, Muhammad Talib Faiz, Yaqoob Ali, Khurram Hashmi, HouJun Tang. Series Active Filter Design Based on Asymmetric Hybrid Modular Multilevel Converter for Traction System. Electronics. 2018; 7 (8):134.
Chicago/Turabian StyleMuhammad Ali; Muhammad Mansoor Khan; Jianming Xu; Muhammad Talib Faiz; Yaqoob Ali; Khurram Hashmi; HouJun Tang. 2018. "Series Active Filter Design Based on Asymmetric Hybrid Modular Multilevel Converter for Traction System." Electronics 7, no. 8: 134.
Microgrids (MGs) are composed of multiple distributed generators (DGs) interfaced to micronetwork through paralleled connected power inverters (PIs). Load sharing among multiple DG units is an important task for autonomous operation of microgrids. In order to realize satisfactory power sharing and voltage regulation between DG units, different voltage droop control strategies have been reported in the literature. In the medium voltage (MV) microgrids, power sharing, and voltage regulation often deteriorate due to dependence on nontrivial feeder impedances. The conventional control strategies are subject to steady-state active and reactive power-sharing errors along with system voltage and frequency deviations. Furthermore, complex microgrid configurations either in looped or meshed networks often make power balancing and voltage regulations more challenging. This paper presents an improved control strategy that can be extended for radial networks in order to enhance the accuracy of power sharing and voltage regulation. The proposed control strategy considers load voltage magnitude regulation as opposed the voltage regulation at inverters terminals. At the same time, a supervisory control loop is added to observe and correct system frequency deviations. This proposed method is aimed at replacing paralleled inverter control methods hitherto used. Simulation studies of the proposed scheme in comparison with the conventional control strategy in MATLAB/Simulink validate the effectiveness of the proposed strategy.
Muhammad Khan; Huawei Jiang; Khurram Hashmi; Muhammad Umair Shahid. An Improved Control Strategy for Three-Phase Power Inverters in Islanded AC Microgrids. Inventions 2018, 3, 47 .
AMA StyleMuhammad Khan, Huawei Jiang, Khurram Hashmi, Muhammad Umair Shahid. An Improved Control Strategy for Three-Phase Power Inverters in Islanded AC Microgrids. Inventions. 2018; 3 (3):47.
Chicago/Turabian StyleMuhammad Khan; Huawei Jiang; Khurram Hashmi; Muhammad Umair Shahid. 2018. "An Improved Control Strategy for Three-Phase Power Inverters in Islanded AC Microgrids." Inventions 3, no. 3: 47.
Improvements in control of renewable energy-based microgrids are a growing area of interest. A hierarchical control structure is popularly implemented to regulate key parameters such as power sharing between generation sources, system frequency and node voltages. A distributed control infrastructure is realized by means of a communication network that spans the micro-distribution grid. Measured and estimated values, as well as corrective signals are transmitted across this network to effect required system regulation. However, intermittent latencies and failures of component communication links may result in power imbalances between generation sources, deviations in node voltages and system frequency. This paper proposes a hierarchical control structure to regulate the operation of an islanded AC microgrid experiencing communication link failures. The proposed strategy aims to virtually sub-divide the microgrid into controllable “islands”. Thereafter, active power sharing, frequency and voltage restoration is achieved by competing converter systems through multi-agent consensus. The effectiveness of the proposed methodology has been verified through stability analyses using system wide mathematical small signal models and case study simulations in MATLAB, Simpower systems.
Khurram Hashmi; Muhammad Mansoor Khan; Huawei Jiang; Muhammad Umair Shahid; Salman Habib; Muhammad Talib Faiz; HouJun Tang. A Virtual Micro-Islanding-Based Control Paradigm for Renewable Microgrids. Electronics 2018, 7, 105 .
AMA StyleKhurram Hashmi, Muhammad Mansoor Khan, Huawei Jiang, Muhammad Umair Shahid, Salman Habib, Muhammad Talib Faiz, HouJun Tang. A Virtual Micro-Islanding-Based Control Paradigm for Renewable Microgrids. Electronics. 2018; 7 (7):105.
Chicago/Turabian StyleKhurram Hashmi; Muhammad Mansoor Khan; Huawei Jiang; Muhammad Umair Shahid; Salman Habib; Muhammad Talib Faiz; HouJun Tang. 2018. "A Virtual Micro-Islanding-Based Control Paradigm for Renewable Microgrids." Electronics 7, no. 7: 105.
Communication-based distributed secondary control is extensively used in DC microgrids. Compared to centralized control, it can provide better voltage regulation and load sharing in microgrids. A conventional secondary control technique that converges the system to a common operating point is improved by using the control methodology to detect the communication link failure and stabilize the system operation during communication islanding. Recently, more robust control schemes have been proposed to improve resilience, but communication islanding has not been addressed at the secondary level control for which the system requires additional tertiary control. However, link failure is a possibility in the microgrid, so this paper proposes a control scheme at the secondary level to detect communication islanding. Communication islanding may lead the system to unpredictable behavior, which may cause the system to become unstable and may further lead to a cascading failure. The proposed control scheme sustains the stability and operation of a DC microgrid. Voltage and current observer works in a parallel manner with the proposed secondary control to achieve a correction term for global operating points. The proposed control scheme has been verified through analysis and simulation.
Muhammad Umair Shahid; Muhammad Mansoor Khan; Khurram Hashmi; Salman Habib; Huawei Jiang; HouJun Tang. A Control Methodology for Load Sharing System Restoration in Islanded DC Micro Grid with Faulty Communication Links. Electronics 2018, 7, 90 .
AMA StyleMuhammad Umair Shahid, Muhammad Mansoor Khan, Khurram Hashmi, Salman Habib, Huawei Jiang, HouJun Tang. A Control Methodology for Load Sharing System Restoration in Islanded DC Micro Grid with Faulty Communication Links. Electronics. 2018; 7 (6):90.
Chicago/Turabian StyleMuhammad Umair Shahid; Muhammad Mansoor Khan; Khurram Hashmi; Salman Habib; Huawei Jiang; HouJun Tang. 2018. "A Control Methodology for Load Sharing System Restoration in Islanded DC Micro Grid with Faulty Communication Links." Electronics 7, no. 6: 90.
In this paper, a generalized tri-state pulse width modulation method (GTSPWM), which decreases the common-mode voltage and current (CMV/CMC), is proposed for Silicon Carbide (SiC) based three-phase two-level voltage-source inverters (VSIs). Mathematical analysis, simulations, and experimental results show that GTSPWM has superior characteristics in terms of reduced switching losses, lesser output current harmonic distortion, reduced DC link current ripple, and lower common mode voltage (CMV). With the usage of SiC MOSFETs, the switching frequency of VSIs can be increased appreciably and the performance of proposed PWM method could be further improved.
Junzhong Xu; Yong Wang; Erlong Zhu; Khurram Hashmi; Xiaoyu Zha; Jingwen Han; HouJun Tang. Generalized tri-state PWM method based high frequency SiC three-phase inverter. 2018 IEEE Applied Power Electronics Conference and Exposition (APEC) 2018, 2465 -2470.
AMA StyleJunzhong Xu, Yong Wang, Erlong Zhu, Khurram Hashmi, Xiaoyu Zha, Jingwen Han, HouJun Tang. Generalized tri-state PWM method based high frequency SiC three-phase inverter. 2018 IEEE Applied Power Electronics Conference and Exposition (APEC). 2018; ():2465-2470.
Chicago/Turabian StyleJunzhong Xu; Yong Wang; Erlong Zhu; Khurram Hashmi; Xiaoyu Zha; Jingwen Han; HouJun Tang. 2018. "Generalized tri-state PWM method based high frequency SiC three-phase inverter." 2018 IEEE Applied Power Electronics Conference and Exposition (APEC) , no. : 2465-2470.
The impending environmental issues and growing concerns for global energy crises are driving the need for new opportunities and technologies that can meet significantly the higher demand of cleaner and sustainable energy systems. This necessitates the development of transportation and power generation systems. The deployment of electric vehicles (EVs) is considered as an emergent solution to meet the current and future energy crises and environmental issues. The electrification of transportation system is a promising approach to green the transportation systems and to reduce the issues of climate change. This paper inspects the present status, latest deployment and challenging issues in implementation of EVs infrastructural and charging systems in conjunction with several international standards and charging codes. In this study, the on-board and off-board categories of charging systems with unidirectional and bidirectional power flow are shown. Unidirectional charging offers hardware limitation and reduce interconnection issues. Bidirectional charging offers the fundamental feature of vehicle to grid technology. Cost issues and requirements for on-board energy storage systems are reduced with the accessibility of charging infrastructures Furthermore, an extensive analysis of international standards which are implemented for deployment of EVs are explained. Our study also compared and evaluated infrastructural and charging systems based on equipment, location and time of charging, cost, amount of power, impacts on the gird and other aspects.
Salman Habib; Muhammad Mansoor Khan; Jiang Huawei; Khurram Hashmi; Muhammad Talib Faiz; HouJun Tang. A study of implemented international standards and infrastructural system for electric vehicles. 2018 IEEE International Conference on Industrial Technology (ICIT) 2018, 1783 -1788.
AMA StyleSalman Habib, Muhammad Mansoor Khan, Jiang Huawei, Khurram Hashmi, Muhammad Talib Faiz, HouJun Tang. A study of implemented international standards and infrastructural system for electric vehicles. 2018 IEEE International Conference on Industrial Technology (ICIT). 2018; ():1783-1788.
Chicago/Turabian StyleSalman Habib; Muhammad Mansoor Khan; Jiang Huawei; Khurram Hashmi; Muhammad Talib Faiz; HouJun Tang. 2018. "A study of implemented international standards and infrastructural system for electric vehicles." 2018 IEEE International Conference on Industrial Technology (ICIT) , no. : 1783-1788.
The performance of zero ozone depletion potential refrigerants is investigated when retrofitted in R22 based air conditioning system. The options evaluated are R407C, R417A, R422D, R427A, and R438A. In order to arrive at most suitable alternative(s) to R22, energy and exergy performance of candidate refrigerants is carried out and compared against that of R22. The COP and exergy efficiencies showed that none of selected refrigerant is as efficient as R22 however their values suggests that each may be considered as potential substitute for retrofitting. Having comparable COP to others but low cooling capacity of R417A makes it less attractive. With comparatively reduced COP, lowest exergy efficiency and highest mass-flow rate, makes R422D the least desirable option. The R407C, R427A, and R438A emerged as most attractive substitutes. The lower discharge temperatures of substitutes will enhance the compressor life. Further, for substitutes there may be a possible change out of expansion valve.
Mian Saeed; Shafiq Qureshi; Khurram Hashmi; Muhammad Khan; Syed Danish. Performance assessment of alternate refrigerants for retrofitting R22 based air conditioning system. Thermal Science 2018, 22, 931 -941.
AMA StyleMian Saeed, Shafiq Qureshi, Khurram Hashmi, Muhammad Khan, Syed Danish. Performance assessment of alternate refrigerants for retrofitting R22 based air conditioning system. Thermal Science. 2018; 22 (2):931-941.
Chicago/Turabian StyleMian Saeed; Shafiq Qureshi; Khurram Hashmi; Muhammad Khan; Syed Danish. 2018. "Performance assessment of alternate refrigerants for retrofitting R22 based air conditioning system." Thermal Science 22, no. 2: 931-941.
The development of electric vehicles (EVs) is an emergent solution to green the transportation systems and to reduce the issues of climate change. This paper inspects the present status, latest deployment and challenging issues in implementation of EVs infrastructure, battery chargers, in conjunction with charging power levels. The performance criteria of batteries are not only based on charging infrastructure and the characteristics of chargers but also on battery design and its types for EVs. In this study, the on-board and off-board categories of charging systems with unidirectional and bidirectional power flow are shown. Unidirectional charging offers hardware limitation and reduce interconnection issues. Bidirectional charging offers the fundamental feature of vehicle to grid technology. Cost issues and requirements for on-board energy storage systems are reduced with the accessibility of charging infrastructures. In particular, three types of power levels, Level 1(Ease), Level 2 (primary) and Level 3 i.e. fast are enlightened. Furthermore, our study analyzed the infrastructure configurations and numerous power level chargers based on equipment, location, time of charging, cost, amount of power, impacts on the gird and other aspects.
Salman Habib; Muhammad Mansoor Khan; Khurram Hashmi; Muhammad Ali; HouJun Tang. A Comparative Study of Electric Vehicles Concerning Charging Infrastructure and Power Levels. 2017 International Conference on Frontiers of Information Technology (FIT) 2017, 327 -332.
AMA StyleSalman Habib, Muhammad Mansoor Khan, Khurram Hashmi, Muhammad Ali, HouJun Tang. A Comparative Study of Electric Vehicles Concerning Charging Infrastructure and Power Levels. 2017 International Conference on Frontiers of Information Technology (FIT). 2017; ():327-332.
Chicago/Turabian StyleSalman Habib; Muhammad Mansoor Khan; Khurram Hashmi; Muhammad Ali; HouJun Tang. 2017. "A Comparative Study of Electric Vehicles Concerning Charging Infrastructure and Power Levels." 2017 International Conference on Frontiers of Information Technology (FIT) , no. : 327-332.
Power sharing in islanded AC microgrids is a growing area of interest for researchers. Droop control methods are basic de-centralized methods of power sharing between power converter nodes in an islanded AC microgrid. However, these methods have certain drawbacks including the need for a secondary control layer to correct deviations in voltage and frequency caused by droop action in primary power sharing control loop. Alternatively, multiagent consensus based control methods utilize localized controls at each converter node such that all nodes work to reach a consensus upon required parameters through communication based sharing of measured values. However, using these methods, reactive power sharing is not satisfactorily achieved. Moreover, the control response tends to be slower and in-accurate. This paper proposes a distributed consensus based control scheme to ensure proportional sharing of both active and reactive power between distributed converters in an islanded AC microgrid, whilst also restoring voltage and frequency to their nominal values. Effectiveness of the proposed method has been verified through simulation studies in MATLAB Sim power systems.
Khurram Hashmi; Muhammad Mansoor Khan; Salman Habib; HouJun Tang. An Improved Control Scheme for Power Sharing between Distributed Power Converters in Islanded AC Microgrids. 2017 International Conference on Frontiers of Information Technology (FIT) 2017, 270 -275.
AMA StyleKhurram Hashmi, Muhammad Mansoor Khan, Salman Habib, HouJun Tang. An Improved Control Scheme for Power Sharing between Distributed Power Converters in Islanded AC Microgrids. 2017 International Conference on Frontiers of Information Technology (FIT). 2017; ():270-275.
Chicago/Turabian StyleKhurram Hashmi; Muhammad Mansoor Khan; Salman Habib; HouJun Tang. 2017. "An Improved Control Scheme for Power Sharing between Distributed Power Converters in Islanded AC Microgrids." 2017 International Conference on Frontiers of Information Technology (FIT) , no. : 270-275.