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Records with Subject: Process Control
Showing records 1 to 25 of 94. [First] Page: 1 2 3 4 Last
Real Time Hybrid Model Predictive Control for the Current Profile of the Tokamak à Configuration Variable (TCV)
Izaskun Garrido, Aitor J. Garrido, Stefano Coda, Hoang B. Le, Jean Marc Moret
January 7, 2019 (v1)
Keywords: fusion reactors, Model Predictive Control, multiloop control, plasma control
Plasma stability is one of the obstacles in the path to the successful operation of fusion devices. Numerical control-oriented codes as it is the case of the widely accepted RZIp may be used within Tokamak simulations. The novelty of this article relies in the hierarchical development of a dynamic control loop. It is based on a current profile Model Predictive Control (MPC) algorithm within a multiloop structure, where a MPC is developed at each step so as to improve the Proportional Integral Derivative (PID) global scheme. The inner control loop is composed of a PID-based controller that acts over the Multiple Input Multiple Output (MIMO) system resulting from the RZIp plasma model of the Tokamak à Configuration Variable (TCV). The coefficients of this PID controller are initially tuned using an eigenmode reduction over the passive structure model. The control action corresponding to the state of interest is then optimized in the outer MPC loop. For the sake of comparison, both the tr... [more]
A Photovoltaic-Based SEPIC Converter with Dual-Fuzzy Maximum Power Point Tracking for Optimal Buck and Boost Operations
Tanaselan Ramalu, Mohd Amran Mohd Radzi, Muhammad Ammirrul Atiqi Mohd Zainuri, Noor Izzri Abdul Wahab, Ribhan Zafira Abdul Rahman
January 7, 2019 (v1)
Keywords: fuzzy logic controller (FLC), maximum power point tracking (MPPT), photovoltaic (PV), single ended primary-inductor converter (SEPIC)
In this paper, a photovoltaic (PV)-based single ended primary-inductor converter (SEPIC) is developed with introduction of dual-fuzzy logic controller (FLC) maximum power point tracking (MPPT) algorithm. Separate FLC parts, for the first time used for MPPT, are configured for optimal operations of both buck and boost operations. During buck operation, a high overshoot voltage exists, and during boost operation, an undershoot voltage occurs, both during the initial rising period. Definitely, a single-FLC MPPT could not be able to minimize both problems, which on the other hand can be handled by the proposed MPPT algorithm. For evaluation purposes, buck operation has been conducted during high irradiance, while during low irradiance, boost operation has been conducted. The dual-FLC MPPT with SEPIC was simulated in MATLAB-Simulink, and further a laboratory prototype was implemented with a TMS320F28335 eZdsp board. Both simulation and experimental results and comparison analysis (with the... [more]
Comparative Analysis of Voltage Control in Battery Power Converters for Inverter-Based AC Microgrids
Woo-Kyu Chae, Jong-Nam Won, Hak-Ju Lee, Jae-Eon Kim, Jaehong Kim
January 7, 2019 (v1)
Keywords: battery, distributed generators (DGs), inverters, load sharing, microgrid, uninterruptable power supply (UPS)
A microgrid is a micro-power system composed of local distributed generators, energy storage systems, loads, and other components in a local power network. Because renewable energy sources show relatively large output power variation, the integration of distributed generators in a microgrid often requires the installation of a large-scale energy storage system. The energy storage system is connected to a local AC bus via the DC/AC converter with an output inductor-capacitor (LC) filter. The energy storage system power converters generally form the local AC bus voltage. This grid-forming operation requires fast and robust voltage control to properly maintain a stable energy flow and high power quality in the local AC bus. In this paper, two major voltage control schemes—double-loop control and direct voltage control—are analytically compared, and their effects on the power quality of the microgrid are illustrated. The dynamic performance is compared through simulations and experimental... [more]
Maximum Power Point Tracking Sensorless Control of an Axial-Flux Permanent Magnet Vernier Wind Power Generator
Xiang Luo, Shuangxia Niu
January 7, 2019 (v1)
Keywords: axial flux permanent magnet machine, MPPT, sensorless control, SMO, vernier machine
Recently, Vernier permanent magnet (VPM) machines, one special case of magnetic flux-modulated (MFM) machines, benefiting from their compact, simple construction and low-speed/ high-torque characteristics, have been receiving increasing interest. In this paper, the Vernier structure is integrated with an axial-flux PM machine to obtain the magnetic gear effect and produce an improved torque density for direct-drive wind power generation application. Another advantage of the proposed machine is that the stator flux rotating speed can be relatively high when the shaft speed is low. With this benefit, sensorless control strategy can be easily implemented in a wide speed range. In this paper, an improved sliding mode observer (SMO) is proposed to estimate the rotor position and the speed of the proposed machine. With the estimated shaft speeds, the maximum power point tracking (MPPT) control strategy is applied to maximize the wind power extraction. The machine design and the sensorless MP... [more]
A High-Precision Control for a ZVT PWM Soft-Switching Inverter to Eliminate the Dead-Time Effect
Baoquan Kou, Hailin Zhang, He Zhang
January 7, 2019 (v1)
Keywords: auxiliary resonant snubber inverter (ARSI), dead-time effect, high precision, soft-switching, Zero-voltage-transition (ZVT)
Attributing to the advantages of high efficiency, low electromagnetic interference (EMI) noise and closest to the pulse-width-modulation (PWM) converter counterpart, zero-voltage-transition (ZVT) PWM soft-switching inverters are very suitable for high-performance applications. However, the conventional control algorithms intended for high efficiency generally results in voltage distortion. Thus, this paper, for the first time, proposes a high-precision control method to eliminate the dead-time effect through controlling the auxiliary current in the auxiliary resonant snubber inverter (ARSI), which is a typical ZVT PWM inverter. The dead-time effect of ARSI is analyzed, which is distinguished from hard-switching inverters. The proposed high-precision control is introduced based on the investigation of dead-time effect. A prototype was developed to verify the effectiveness of the proposed control. The experimental results shows that the total harmonic distortion (THD) of the output curre... [more]
Earliest Deadline Control of a Group of Heat Pumps with a Single Energy Source
Jiří Fink, Richard P. van Leeuwen
January 7, 2019 (v1)
Keywords: combined heat and power control, domestic hot water, floor heating, heat pump control, Model Predictive Control, Optimization, renewable energy integration, smart grids, smart control, thermal storage
In this paper, we develop and investigate the optimal control of a group of 104 heat pumps and a central Combined Heat and Power unit (CHP). The heat pumps supply space heating and domestic hot water to households. Each house has a buffer for domestic hot water and a floor heating system for space heating. Electricity for the heat pumps is generated by a central CHP unit, which also provides thermal energy to a district heating system. The paper reviews recent smart grid control approaches for central and distributed levels. An online algorithm is described based on the earliest deadline first theory that can be used on the aggregator level to control the CHP and to give signals to the heat pump controllers if they should start or should wait. The central controller requires only a limited amount of privacy-insensitive information from the heat pump controllers about their deadlines, which the heat pump controllers calculate for themselves by model predictions. In this way, a robust he... [more]
DC-Link Capacitor Voltage Regulation for Three-Phase Three-Level Inverter-Based Shunt Active Power Filter with Inverted Error Deviation Control
Yap Hoon, Mohd Amran Mohd Radzi, Mohd Khair Hassan, Nashiren Farzilah Mailah
January 7, 2019 (v1)
Keywords: active power filter, current harmonics, fuzzy logic controller (FLC), inverted error deviation (IED), multilevel power converter, power electronics, power quality
A new control technique known as inverted error deviation (IED) control is incorporated into the main DC-link capacitor voltage regulation algorithm of a three-level neutral-point diode clamped (NPC) inverter-based shunt active power filter (SAPF) to enhance its performance in overall DC-link voltage regulation so as to improve its harmonics mitigation performances. In the SAPF controller, DC-link capacitor voltage regulation algorithms with either the proportional-integral (PI) or fuzzy logic control (FLC) technique have played a significant role in maintaining a constant DC-link voltage across the DC-link capacitors. However, both techniques are mostly operated based on a direct voltage error manipulation approach which is insufficient to address the severe DC-link voltage deviation that occurs during dynamic-state conditions. As a result, the conventional algorithms perform poorly with large overshoot, undershoot, and slow response time. Therefore, the IED control technique is propo... [more]
Boost Pressure Control Strategy to Account for Transient Behavior and Pumping Losses in a Two-Stage Turbocharged Air Path Concept
Thivaharan Albin, Dennis Ritter, Norman Liberda, Dirk Abel
January 7, 2019 (v1)
Keywords: air path control, boost pressure control, internal combustion engines, two-stage turbocharging
Increasingly complex air path concepts are investigated to achieve a substantial reduction in fuel consumption while improving the vehicle dynamics. One promising technology is the two-stage turbocharging for gasoline engines, where a high pressure and a low pressure turbocharger are placed in series. For exploiting the high potential, a control concept has to be developed that allows for coordinated management of the two turbocharger stages. In this paper, the control strategy is investigated. Therefore, the effect of the actuated values on transient response and pumping losses is analyzed. Based on these findings, an optimization-based control algorithm is developed that allows taking both requirements into account. The developed new controller allows achieving a fast transient response, while at the same time reducing pumping losses in stationary operation.
Power Control Strategies of On-Road Charging for Electric Vehicles
Linlin Tan, Jinpeng Guo, Xueliang Huang, Han Liu, Changxin Yan, Wei Wang
January 7, 2019 (v1)
Keywords: magnetic resonant, on-road charging, power control strategies
On-road charging systems for electric vehicles (EVs) have shown revolutionary potential in extending driving range and reducing battery capacities. The optimal equivalent load resistances to maximize receiving power of each EV according to different EV amounts are investigated. This paper introduces a typical on-road charging system with a single transmitting coil and multiple receiving coils. The equivalent circuit models according to different numbers of EVs are built. Power control strategies with regard to a varying number of EVs are then presented. Specifically, self-adaptive source voltage based on primary current detection is utilized to charge EVs, while the source can support enough EVs by providing the rated power. Otherwise, the source voltage is regulated to its maximum value and the charging energy of each EV is suggested to be controlled by adjusting the individual driving speed. A remarkable feature of the power control strategies is that the charging power for each EV i... [more]
A Feed-Forward Control Realizing Fast Response for Three-Branch Interleaved DC-DC Converter in DC Microgrid
Haojie Wang, Minxiao Han, Wenli Yan, Guopeng Zhao, Josep M. Guerrero
January 7, 2019 (v1)
Keywords: DC micro-grid, feed-forward control, response speed, storage battery, three-branch interleaved DC-DC converter
It is a common practice for storage batteries to be connected to DC microgrid buses through DC-DC converters for voltage support on islanded operation mode. A feed-forward control based dual-loop constant voltage PI control for three-branch interleaved DC-DC converters (TIDC) is proposed for storage batteries in DC microgrids. The working principle of TIDC is analyzed, and the factors influencing the response rate based on the dual-loop constant voltage control for TIDC are discussed, and then the method of feed-forward control for TIDC is studied to improve the response rate for load changing. A prototype of the TIDC is developed and an experimental platform is built. The experiment results show that DC bus voltage sags or swells caused by load changing can be reduced and the time for voltage recovery can be decreased significantly with the proposed feed-forward control.
A Novel DFIG Damping Control for Power System with High Wind Power Penetration
Aiguo Tan, Xiangning Lin, Jinwen Sun, Ran Lyu, Zhengtian Li, Long Peng, Muhammad Shoaib Khalid
January 7, 2019 (v1)
Keywords: adaptive damping control, DFIG supplementary control, doubly fed induction generator (DFIG), power oscillation, small signal stability
Aiming at the fact that large-scale penetration of wind power will to some extent weaken the small signal stability of power systems, in this paper, the dynamic model of a doubly fed induction generator (DFIG) is established firstly, to analyze the impact of wind generation on power oscillation damping. Then, based on the conventional maximum power point tracking control of variable speed wind turbine, a supplementary control scheme is proposed to increase the damping of power system. To achieve best performance, parameters of the damping control are tuned by using a genetic algorithm. Results of eigenvalue analysis and simulations demonstrate the effectiveness of supplementary damping control with fixed wind speed. At last, due to the problem that fluctuation of output power of wind generators would cause the unstable performance of the DFIG damping controller above, a new algorithm that adapts to the wind variation is added to the supplementary damping control scheme. Results of the... [more]
Control of a Dual-Stator Flux-Modulated Motor for Electric Vehicles
Xinhua Guo, Shaozhe Wu, Weinong Fu, Yulong Liu, Yunchong Wang, Peihuang Zeng
January 7, 2019 (v1)
Keywords: decouple control, dual-stator, electric vehicles (EVs), flux-modulated, vector control (VC)
This paper presents the control strategies for a novel dual-stator flux-modulated (DSFM) motor for application in electric vehicles (EVs). The DSFM motor can be applied to EVs because of its simple winding structure, high reliability, and its use of two stators and rotating modulation steels in the air gap. Moreover, it outperforms conventional brushless doubly-fed machines in terms of control performance. Two stator-current-oriented vector controls with different excitation in the primary winding, direct and alternating current excitation, are designed, simulated, and evaluated on a custom-made DSFM prototype allowing the decoupled control of torque. The stable speed response and available current characteristics strongly validate the feasibility of the two control methods. Furthermore, the proposed control methods can be employed in other applications of flux-modulated motors.
Analysis and Controller Design of a Universal Bidirectional DC-DC Converter
Kou-Bin Liu, Chen-Yao Liu, Yi-Hua Liu, Yuan-Chen Chien, Bao-Sheng Wang, Yong-Seng Wong
January 7, 2019 (v1)
Keywords: adaptive phase-shift control, bidirectional buck–boost DC-DC converter, zero voltage switching
In this paper, first the operating principles of a non-isolated universal bidirectional DC-DC converter are studied and analyzed. The presented power converter is capable of operating in all power transferring directions in buck/boost modes. Zero voltage switching can be achieved for all the power switches through proper modulation strategy design, therefore, the presented converter can achieve high efficiency. To further improve the efficiency, the relationship between the phase-shift angle and the overall system efficiency is analyzed in detail, an adaptive phase-shift (APS) control method which determines the phase-shift value between gating signals according to the load level is then proposed. As the modulation strategy is a software-based solution, there is no requirement for additional circuits, therefore, it can be implemented easily and instability and noise susceptibility problems can be reduced. To validate the correctness and the effectiveness of the proposed method, a 300 W... [more]
Super-Twisting Differentiator-Based High Order Sliding Mode Voltage Control Design for DC-DC Buck Converters
Yigeng Huangfu, Shengrong Zhuo, Akshay Kumar Rathore, Elena Breaz, Babak Nahid-Mobarakeh, Fei Gao
January 7, 2019 (v1)
Keywords: DC-DC converter, high-order sliding mode, robust control, sensor-less
This paper aims to focus on the smooth output of DC-DC buck converters in wireless power transfer systems under input perturbations and load disturbances using the high-order sliding mode controller (HOSM) and HOSM with super-twisting differentiator (HOSM + STD). The proposed control approach needs only measurement of converter output voltage. Theoretical analysis and design procedures, as well as the super-twisting differentiator of the proposed controller are presented in detail with the prescribed convergence law of high-order sliding modes. Comparisons of both simulation and experimental results among conventional proportional-integral (PI) control, traditional sliding mode control (SMC), HOSM and HOSM + STD under various test conditions such as steady state, input voltage perturbations and output load disturbances, are presented and discussed. The results demonstrate and validate the effectiveness and robustness of the proposed control method.
Coordinated Control of Wave Energy Converters Subject to Motion Constraints
Liguo Wang, Jens Engström, Mats Leijon, Jan Isberg
November 28, 2018 (v1)
Keywords: coordinated control, frequency domain, motion constraints, optimal damping, wave energy farm
In this paper, a generic coordinated control method for wave energy converters is proposed, and the constraints on motion amplitudes and the hydrodynamic interaction between converters are considered. The objective of the control problem is to maximize the energy converted from ocean waves, and this is achieved by coordinating the power take-off (PTO) damping of each wave energy converter in the frequency domain in each sea state. In a case study, a wave energy farm consisting of four converters based on the concept developed by Uppsala University is studied. In the solution, motion constraints, including constraints on the amplitudes of displacement and velocity, are included. Twelve months of sea states, based on measured wave data at the Lysekil test site on the Swedish west coast, are used in the simulation to evaluate the performance of the wave energy farm using the new method. Results from the new coordinated control method and traditional control method are compared, indicating... [more]
Study of the Injection Control Strategies of a Compression Ignition Free Piston Engine Linear Generator in a One-Stroke Starting Process
Huihua Feng, Yuyao Guo, Yu Song, Chendong Guo, Zhengxing Zuo
November 28, 2018 (v1)
Keywords: free piston engine, injection control strategies, linear motor
For a compression ignition (CI) free piston engine linear generator (FPLG), injection timing is one of the most important parameters that affect its performance, especially for the one-stroke starting operation mode. In this paper, two injection control strategies are proposed using piston position and velocity signals. It was found experimentally that the injection timing’s influence on the compression ratio, the peak in-cylinder gas pressure and the indicated work (IW) is different from that of traditional reciprocating CI engines. The maximum IW of the ignition starting cylinder, say left cylinder (LC) and the right cylinder (RC) are 132.7 J and 138.1 J, respectively. The thermal-dynamic model for simulating the working processes of the FPLG are built and verified by experimental results. The numerical simulation results show that the running instability and imbalance between LC and RC are the obvious characters when adopting the injection strategy of the velocity feedback. These co... [more]
Sliding Mode Variable Structure Control of a Bearingless Induction Motor Based on a Novel Reaching Law
Zebin Yang, Ling Wan, Xiaodong Sun, Fangli Li, Lin Chen
November 28, 2018 (v1)
Keywords: adaptive variable-rated reaching law, adaptive variable-rated sliding mode controller (ASMC), Bearingless Induction Motor (BIM), chattering, robustness
In order to improve the performance of the Bearingless Induction Motor (BIM) under large disturbances (such as parameter variations and load disturbances), an adaptive variable-rated sliding mode controller (ASMC) is designed to obtain better performance of the speed regulation system. Firstly, the L 1 norm of state variables is applied to the conventional exponential reaching law and an adaptive variable-rated exponential reaching law is proposed to reduce system chattering and improve bad convergence performance of the sliding mode variable structure. Secondly, an integral sliding-mode hyper plane is produced according to the speed error in speed regulation system of BIM. Current signal is extracted by the combination of the sliding-mode hyper plane, the electromagnetic torque and the equation of motion. Finally, the feedback speed can adjust operating state adaptively according to speed error and make system chattering-free moving. The simulation and experiment results sho... [more]
Dynamic Stall Control on the Wind Turbine Airfoil via a Co-Flow Jet
He-Yong Xu, Chen-Liang Qiao, Zheng-Yin Ye
November 28, 2018 (v1)
Keywords: co-flow jet, dynamic stall, flow control, numerical simulation, wind turbine
Dynamic stall control of a S809 airfoil is numerically investigated by implementing a co-flow jet (CFJ). The numerical methods of the solver are validated by comparing results with the baseline experiment as well as a NACA 6415-based CFJ experiment, showing good agreement in both static and dynamic characteristics. The CFJ airfoil with inactive jet is simulated to study the impact that the jet channel imposes upon the dynamic characteristics. It is shown that the presence of a long jet channel could cause a negative effect of decreasing lift and increasing drag, leading to fluctuating extreme loads in terms of drag and moment. The main focus of the present research is the investigation of the dynamic characteristics of the CFJ airfoil with three different jet momentum coefficients, which are compared with the baseline, giving encouraging results. Dynamic stall can be greatly suppressed, showing a very good control performance of significantly increased lift and reduced drag and moment.... [more]
Development of Near Optimal Rule-Based Control for Plug-In Hybrid Electric Vehicles Taking into Account Drivetrain Component Losses
Hanho Son, Hyunsoo Kim
November 28, 2018 (v1)
Keywords: drivetrain component losses, dynamic programming (DP), mode control strategy, plug-in hybrid electric vehicle (PHEV)
A near-optimal rule-based mode control (RBC) strategy was proposed for a target plug-in hybrid electric vehicle (PHEV) taking into account the drivetrain losses. Individual loss models were developed for drivetrain components including the gears, planetary gear (PG), bearings, and oil pump, based on experimental data and mathematical governing equations. Also, a loss model for the power electronic system was constructed, including loss from the motor-generator while rotating in the unloaded state. To evaluate the effect of the drivetrain losses on the operating mode control strategy, backward simulations were performed using dynamic programming (DP). DP selects the operating mode, which provides the highest efficiency for given driving conditions. It was found that the operating mode selection changes when drivetrain losses are included, depending on driving conditions. An operating mode schedule was developed with respect to the wheel power and vehicle speed, and based on the operatin... [more]
A Novel Single Winding Structure and Closed Loop Control of the Suspension Force Vector of Bearingless Permanent Magnet Synchronous Motors
Huangqiu Zhu, Jianfei Yuan, Jintao Jv
November 27, 2018 (v1)
Keywords: bearingless permanent magnet synchronous motors (BPMSM), closed loop control of suspension force vector, finite element analysis (FEA), simulation and experiment, T-shaped single winding configuration
At present, because of their advantages of simple structure, low cost, low power consumption and high efficiency, single winding bearingless permanent magnet synchronous motors (SBPMSMs) have become one of the research hotspots in the bearingless technology field. However, a high motional-electromotive force (EMF) is generated by rotor rotation in the single winding, which already has side-effects on the normal suspension force current, and the suspension force response can be delayed. Because the method of double torque current inverse injection in the symmetrical winding allows the motional-EMFs of the corresponding phase windings to offset each other in the opposite direction, with no adverse effects on original performance, a T-shaped single winding configuration is proposed to realize precisely that effect. In this paper, the analytical expressions of the radial suspension force and torque are deduced and the motional-EMF and performance are analyzed by finite element method using... [more]
Experiments on the Performance of Small Horizontal Axis Wind Turbine with Passive Pitch Control by Disk Pulley
Yu-Jen Chen, Y. C. Shiah
November 27, 2018 (v1)
Keywords: blade element momentum theory, disk pulley, passive pitch control, small horizontal axis wind turbine
The present work is to design a passive pitch-control mechanism for small horizontal axis wind turbine (HAWT) to generate stable power at high wind speeds. The mechanism uses a disk pulley as an actuator to passively adjust the pitch angle of blades by centrifugal force. For this design, aerodynamic braking is caused by the adjustment of pitch angles at high wind speeds. As a marked advantage, this does not require mechanical brakes that would incur electrical burn-out and structural failure under high speed rotation. This can ensure the survival of blades and generator in sever operation environments. In this paper, the analysis uses blade element momentum theory (BEMT) to develop graphical user interface software to facilitate the performance assessment of the small-scale HAWT using passive pitch control (PPC). For verification, the HAWT system was tested in a full-scale wind tunnel for its aerodynamic performance. At low wind speeds, this system performed the same as usual, yet at h... [more]
The Study of Fuzzy Proportional Integral Controllers Based on Improved Particle Swarm Optimization for Permanent Magnet Direct Drive Wind Turbine Converters
Yancai Xiao, Tieling Zhang, Zeyu Ding, Chunya Li
November 27, 2018 (v1)
Keywords: converter, fuzzy PI controller, particle swarm optimization (PSO), permanent magnet direct drive (PMDD) wind turbine
In order to meet the requirements of high precision and fast response of permanent magnet direct drive (PMDD) wind turbines, this paper proposes a fuzzy proportional integral (PI) controller associated with a new control strategy for wind turbine converters. The purpose of the control strategy is to achieve the global optimization for the quantization factors, ke and kec, and scale factors, kup and kui, of the fuzzy PI controller by an improved particle swarm optimization (PSO) method. Thus the advantages of the rapidity of the improved PSO and the robustness of the fuzzy controller can be fully applied in the control process. By conducting simulations for 2 MW PMDD wind turbines with Matlab/Simulink, the performance of the fuzzy PI controller based on the improved PSO is demonstrated to be obviously better than that of the PI controller or the fuzzy PI controller without using the improved PSO under the situation when the wind speed changes suddenly.
A Novel Neural Network Vector Control for Single-Phase Grid-Connected Converters with L, LC and LCL Filters
Xingang Fu, Shuhui Li
November 27, 2018 (v1)
Keywords: decoupled vector control, dynamic programming, Levenberg–Marquardt (LM) algorithm, neural network (NN) vector control, single-phase grid-connected converter (GCC)
This paper investigates a novel recurrent neural network (NN)-based vector control approach for single-phase grid-connected converters (GCCs) with L (inductor), LC (inductor-capacitor) and LCL (inductor-capacitor-inductor) filters and provides their comparison study with the conventional standard vector control method. A single neural network controller replaces two current-loop PI controllers, and the NN training approximates the optimal control for the single-phase GCC system. The Levenberg⁻Marquardt (LM) algorithm was used to train the NN controller based on the complete system equations without any decoupling policies. The proposed NN approach can solve the decoupling problem associated with the conventional vector control methods for L, LC and LCL-filter-based single-phase GCCs. Both simulation study and hardware experiments demonstrate that the neural network vector controller shows much more improved performance than that of conventional vector controllers, including faster resp... [more]
A New Approach of Modeling an Ultra-Super-Critical Power Plant for Performance Improvement
Guolian Hou, Yu Yang, Zhuo Jiang, Quan Li, Jianhua Zhang
November 27, 2018 (v1)
Keywords: coordinated control system, Modelling, performance improvement, T-S fuzzy model, ultra super-critical power plant
A suitable model of coordinated control system (CCS) with high accuracy and simple structure is essential for the design of advanced controllers which can improve the efficiency of the ultra-super-critical (USC) power plant. Therefore, with the demand of plant performance improvement, an improved T-S fuzzy model identification approach is proposed in this paper. Firstly, the improved entropy cluster algorithm is applied to identify the premise parameters which can automatically determine the cluster numbers and initial cluster centers by introducing the concept of a decision-making constant and threshold. Then, the learning algorithm is used to modify the initial cluster center and a new structure of concluding part is discussed, the incremental data around the cluster center is used to identify the local linear model through a weighted recursive least-square algorithm. Finally, the proposed approach is employed to model the CCS of a 1000 MW USC one-through boiler power plant by using... [more]
Analysis of a Battery Management System (BMS) Control Strategy for Vibration Aged Nickel Manganese Cobalt Oxide (NMC) Lithium-Ion 18650 Battery Cells
Thomas Bruen, James Michael Hooper, James Marco, Miguel Gama, Gael Henri Chouchelamane
November 27, 2018 (v1)
Keywords: battery management system (BMS), electric vehicle (EV), hybrid electric vehicle (HEV), Li-ion battery ageing, vehicle vibration
Electric vehicle (EV) manufacturers are using cylindrical format cells as part of the vehicle’s rechargeable energy storage system (RESS). In a recent study focused at determining the ageing behavior of 2.2 Ah Nickel Manganese Cobalt Oxide (NMC) Lithium-Ion 18650 battery cells, significant increases in the ohmic resistance (RO) were observed post vibration testing. Typically a reduction in capacity was also noted. The vibration was representative of an automotive service life of 100,000 miles of European and North American customer operation. This paper presents a study which defines the effect that the change in electrical properties of vibration aged 18650 NMC cells can have on the control strategy employed by the battery management system (BMS) of a hybrid electric vehicle (HEV). It also proposes various cell balancing strategies to manage these changes in electrical properties. Subsequently this study recommends that EV manufacturers conduct vibration testing as part of their cell... [more]
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