A multi-valve controlled saturable reactor and its harmonic optimization

2014 ◽  
Vol 33 (4) ◽  
pp. 1346-1365 ◽  
Author(s):  
Yifan Wang ◽  
Guozhu Chen
Keyword(s):  
Mathematical Model ◽  
Harmonic Analysis ◽  
Harmonic Distortion ◽  
Iron Core ◽  
Harmonic Suppression ◽  
Output Current ◽  
Harmonic Compensation ◽  
Content Type ◽  
Current Harmonics ◽  
The Mathematical Model

Purpose – As arc suppression coils (ASCs), magnetically controlled reactors (MCRs) are usually operated in the single-phase mode. Due to the lack of a third order harmonic compensation circuit, the current harmonics are high. The purpose of this paper is to propose a novel structure of MCR and a genetic algorithm (GA) to determine the parameters which will result in minimum total harmonics. Design/methodology/approach – This paper proposes the structure and the working principle of the multi-valve controlled saturable reactor (MCSR). There are several sorts of magnetic valves in the iron cores of the MCSR. The saturation degree of each magnetic valve is different when the same direct component of the magnetic flux is generated in the iron core, therefore current harmonics of different phases emerging, i.e. the total harmonics can be reduced. The magnetization characteristics and the mathematical model of the current harmonics of the MCSR are presented by introducing three parameters. The optimal values of the parameters that result in the smallest total harmonic distortion in the output current are calculated by a GA. Findings – The simulation and experimental results are coincident with the theoretical analyses, which prove the effectiveness of the proposed method on harmonic suppression. Practical implications – The method proposed in this paper can successfully reduce the current harmonics of the conventional MCR, including but not limited to the ASC. A prototype MCSR (540 kVA/10 kV) has been designed and constructed. Originality/value – In this paper, a MCSR is proposed. The mathematical model of the MCSR for harmonic analysis is developed. The optimal parameters that result in the smallest THD in the output current are calculated. The mathematical model can be also used for the harmonic analysis of conventional MCRs.

scholarly journals Mathematical modeling and harmonic analysis of SISFCL

2017 ◽  
Vol 36 (1) ◽  
pp. 258-270
Author(s):  
Debraj Sarkar ◽  
Debabrata Roy ◽  
Amalendu Bikash Choudhury ◽  
Sotoshi Yamada
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Harmonic Analysis ◽  
Voltage Drop ◽  
Element Model ◽  
Iron Core ◽  
Content Type ◽  
Hysteresis Characteristic ◽  
The Core ◽  
The Mathematical Model

Purpose A saturated iron core superconducting fault current limiter (SISFCL) has an important role to play in the present-day power system, providing effective protection against electrical faults and thus ensuring an uninterrupted supply of electricity to the consumers. Previous mathematical models developed to describe the SISFCL use a simple flux density-magnetic field intensity curve representing the ferromagnetic core. As the magnetic state of the core affects the efficient working of the device, this paper aims to present a novel approach in the mathematical modeling of the device with the inclusion of hysteresis. Design/methodology/approach The Jiles–Atherton’s hysteresis model is utilized to develop the mathematical model of the limiter. The model is numerically solved using MATLAB. To support the validity of model, finite element model (FEM) with similar specifications was simulated. Findings Response of the limiter based on the developed mathematical model is in close agreement with the FEM simulations. To illustrate the effect of the hysteresis, the responses are compared by using three different hysteresis characteristics. Harmonic analysis is performed and comparison is carried out utilizing fast Fourier transform and continuous wavelet transform. It is observed that the core with narrower hysteresis characteristic not only produces a better current suppression but also creates a higher voltage drop across the DC source. It also injects more harmonics in the system under fault condition. Originality/value Inclusion of hysteresis in the mathematical model presents a more realistic approach in the transient analysis of the device. The paper provides an essential insight into the effect of the core hysteresis characteristic on the device performance.

scholarly journals Composite Control Strategy of Output Current of LCL Photovoltaic Grid-Connected Inverter

2021 ◽  
Vol 2136 (1) ◽  
pp. 012015
Author(s):  
Shengqing Li ◽  
Xinluo Li ◽  
Qiang Wu ◽  
Xiafei Long
Keyword(s):  
Control Strategy ◽  
Block Diagram ◽  
Harmonic Distortion ◽  
Harmonic Suppression ◽  
Output Current ◽  
Control Block ◽  
Current Harmonics ◽  
Suppression Effect ◽  
Composite Control ◽  
Grid Connected Inverter

Abstract In order to further optimize the output current harmonic suppression effect of photovoltaic grid-connected inverters, a composite control strategy of LCL type photovoltaic grid-connected inverter output current is proposed. This strategy combines proportional complex integral (PCI) control and repetitive control (RC) in parallel, draws a composite control block diagram, introduces a transfer function, and designs PCI and RC control parameters. Prove that the compound control can reduce current harmonics, achieved the purpose of reducing the steady-state error of the fundamental frequency. And adopts a new PCI composite control strategy, which helps to save the cost of the control system. By building the MATLAB/Simulink simulation platform and establishing the PCI+RC composite control model of LCL photovoltaic grid-connected inverter, the comparison of the simulation results shows that compared with the PI+RC control strategy, the total harmonic distortion rate of the grid-connected current is reduced by 25.77. %, significantly improving the quality of grid-connected current.

Force tracking control of grinding end effector based on backstepping + PID

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shijie Dai ◽  
Shining Li ◽  
Wenbin Ji ◽  
Zhenlin Sun ◽  
Yufeng Zhao
Keyword(s):  
Mathematical Model ◽  
Linear System ◽  
Control Strategy ◽  
Grinding Force ◽  
Constant Force ◽  
End Effector ◽  
Content Type ◽  
Modeling And Analysis ◽  
The Mathematical Model ◽  
Automobile Wheel

Purpose This study aims to realize the constant force grinding of automobile wheel hub. Design/methodology/approach A force control strategy of backstepping + proportion integration differentiation (PID) is proposed. The grinding end effector is installed on the flange of the robot. The robot controls the position and posture of the grinding end actuator and the grinding end actuator controls the grinding force output. First, the modeling and analysis of the grinding end effector are carried out, and then the backstepping + PID method is adopted to control the grinding end effector to track the expected grinding force. Finally, the feasibility of the proposed method is verified by simulation and experiment. Findings The simulation and experimental results show that the backstepping + PID strategy can track the expected force quickly, and improve the dynamic response performance of the system and the quality of grinding and polishing of automobile wheel hub. Research limitations/implications The mathematical model is based on the pneumatic system and ideal gas, and ignores the influence of friction in the working process of the cylinder, so the mathematical model proposed in this study has certain limitations. A new control strategy is proposed, which is not only used to control the grinding force of automobile wheels, but also promotes the development of industrial control. Social implications The automatic constant force grinding of automobile wheel hub is realized, and the manpower is liberated. Originality/value First, the modeling and analysis of the grinding end effector are carried out, and then the backstepping + PID method is adopted to control the grinding end effector to track the expected grinding force. The nonlinear model of the system is controlled by backstepping method, and in the process, the linear system composed of errors is obtained, and then the linear system is controlled by PID to realize the combination of backstepping and PID control.

scholarly journals Grid-Connected Resonance Suppression Of Group-Series Photovoltaic Cluster Inverters Based On Hybrid Damping

2021 ◽  
Vol 2136 (1) ◽  
pp. 012020
Author(s):  
Shengqing Li ◽  
Zhijian Wang
Keyword(s):  
Harmonic Distortion ◽  
Current Loop ◽  
Output Current ◽  
Resonance Mechanism ◽  
Current Feedback ◽  
Parallel Voltage ◽  
The Mathematical Model ◽  
Parallel Current ◽  
Suppression Strategy ◽  
Hybrid Damping

Abstract Grid-connected group-series photovoltaic cluster inverter system will cause resonance, which will adversely affect the system. To suppress grid-connected resonance, the mathematical model, resonance mechanism and resonance characteristics of the cluster inverters are analyzed, and a global resonance suppression strategy based on hybrid damping is proposed. In the current loop of the inverter, capacitive current feedback and parallel voltage proportional feed-forward are introduced as active dampers to reduce the harmonics of the parallel current. On this basis, RLC type second-order resonance suppression circuit is added as passive damping to suppress system resonance, so that the output current of the inverters can meet the grid-connected conditions when the cluster is connected to the grid. The simulation and experimental results show that the total harmonic distortion of the grid-connected current decreases from 10.54% to 1.97% after three series photovoltaic cluster inverters adopt this strategy, which effectively suppresses the grid-connected resonance.

Wind-driven land-yacht robot mathematical modeling and verification

2016 ◽  
Vol 43 (1) ◽  
pp. 77-90 ◽  
Author(s):  
Jiqing Chen ◽  
Shaorong Xie ◽  
Jun Luo ◽  
Hengyu Li
Keyword(s):  
Mathematical Model ◽  
Experimental Tests ◽  
Outer Planet ◽  
Mechanism Analysis ◽  
Content Type ◽  
The Antarctic ◽  
The Mathematical Model ◽  
The Given ◽  
Practical Implications ◽  
Wind Resources

Purpose – The purpose of this paper was to solve the shortage of carrying energy in probing robot and make full use of wind resources in the Antarctic expedition by designing a four-wheel land-yacht. Land-yacht is a new kind of mobile robot powered by the wind using a sail. The mathematical model and trajectory of the land-yacht are presented in this paper. Design/methodology/approach – The mechanism analysis method and experimental modeling method are used to establish a dual-input and dual-output mathematical model for the motion of land-yacht. First, the land-yacht’s model structure is obtained by using mechanism analysis. Then, the models of steering gear, servomotors and force of wing sail are analyzed and validated. Finally, the motion of land-yacht is simulated according to the mathematical model. Findings – The mathematical model is used to analyze linear motion and steering motion. Compared with the simulation results and the actual experimental tests, the feasibility and reliability of the proposed land-yacht modeling are verified. It can travel according to the given signal. Practical implications – This land-yacht can be used in the Antarctic, outer planet or for harsh environment exploration. Originality/value – A land-yacht is designed, and the contribution of this research is the development of a mathematical model for land-yacht robot. It provides a theoretical basis for analysis of the land-yacht’s motion.

Using Fintech in scaling up Islamic microfinance

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Salman Ahmed Shaikh
Keyword(s):  
Mathematical Model ◽  
Financial Services ◽  
Financial Support ◽  
Institutional Design ◽  
Supply Side ◽  
Empirical Estimation ◽  
Content Type ◽  
Funding Sources ◽  
Islamic Microfinance ◽  
The Mathematical Model

Purpose This study aims to propose a hybrid microfinance model that integrates various Islamic commercial and social finance institutions through Fintech for efficient and impactful results. The microfinance model caters to the financial and social intermediation needs through a set of financial services and non-financial support. Design/methodology/approach The study uses both a mathematical model and an empirical estimation using micro panel data to establish the core problem in microfinance operations. Conclusions from the mathematical model and estimated results in the empirical analysis are used to suggest an institutional design which embeds technology in the delivery of Islamic microfinance in an integrated structure. For screening and incentive conditions, the study gives illustration through numerical examples. Findings The mathematical model highlights the need for financial sustainability, outreach, scale and complementariness of non-financial factors such as commitment, repayment incentives and skills enhancement multiplier. In light of this, the proposed Islamic microfinance model is outlined to create synergies by integrating a diversity of funding sources through social savings and impact investments. The programme also blends financial services with non-financial support to ensure engagement and commitment on a long-term basis. It uses Fintech in various demand and supply-side operations to show how technology embeddedness can help in achieving cost efficiencies and extend outreach. Originality/value It is the first study in integrated institutional design in Islamic microfinance literature that embeds Fintech in both demand side and supply side operations comprehensively. The proposed model is conducive for enhancing outreach, scale and impact in the Islamic microfinancial services.

Mathematical model of one flexible transport category aircraft

2017 ◽  
Vol 89 (3) ◽  
pp. 384-396 ◽  
Author(s):  
Marcelo Santiago Sousa ◽  
Pedro Paglione ◽  
Roberto Gil Annes Silva ◽  
Flavio Luiz Cardoso-Ribeiro ◽  
Sebastião Simões Cunha
Keyword(s):  
Mathematical Model ◽  
Structural Dynamics ◽  
Degrees Of Freedom ◽  
Flight Dynamics ◽  
Content Type ◽  
Nonlinear Structural Dynamics ◽  
Nonlinear Structural ◽  
Structural Deformations ◽  
Dynamics Simulations ◽  
The Mathematical Model

Purpose The purpose of this paper is to present a mathematical model of one very flexible transport category airplane whose structural dynamics was modeled with the strain-based formulation. This model can be used for the analysis of couplings between the flight dynamics and structural dynamics. Design/methodology/approach The model was developed with the use of Hamiltonian mechanics and strain-based formulation. Nonlinear flight dynamics, nonlinear structural dynamics and inertial couplings are considered. Findings The mathematical model allows the analysis of effects of high structural deformations on airplane flight dynamics. Research limitations/implications The mathematical model has more than 60 degrees of freedom. The computational burden is too high, if compared to the traditional rigid body flight dynamics simulations. Practical implications The mathematical model presented in this work allows a detailed analysis of the couplings between flight dynamics and structural dynamics in very flexible airplanes. The better comprehension of these couplings will contribute to the development of flexible airplanes. Originality/value This work presents the application of nonlinear flight dynamics-nonlinear structural dynamics-strain-based formulation (NFNS_s) methodology to model the flight dynamics of one very flexible transport category airplane. This paper addresses also the way as the analysis of results obtained in nonlinear simulations can be made. Comparisons of the NFNS_s and nonlinear flight dynamics-linear structural dynamics methodologies are presented in this work.

scholarly journals PERANCANGAN INVERTER SATU FASA OFF-GRID MENGGUNAKAN DSPIC30F4011 DENGAN KONTROL ARUS METODE PROPORTIONAL RESONANT

TRANSIENT ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 753
Author(s):  
Segal Mancini Suroso ◽  
Iwan Setiawan ◽  
Bambang Winardi
Keyword(s):  
Power Plants ◽  
Harmonic Distortion ◽  
Current Control ◽  
System Response ◽  
Output Current ◽  
Current Output ◽  
Current Harmonics ◽  
Pv Systems ◽  
Bridge Type

The availability of fossil as fuel in conventional power plants is running low. This causes the use of renewable energy such as photovoltaic (PV) technology becomes very important. PV systems required inverters for converting DC voltage into AC voltage, where the quality of the inverter output current is very influential on the quality of power. Therefore, it is necessary to control the inverter current output which serves to improve the system response and minimize the current harmonics. In this research, a H-Bridge type of one phase Inverter is designed using 16-bit DSPIC30F4011 microcontroller with current control proportional resonant method. The inverter output current is fedback by the ACS712-05B current sensor. The test is carried out with the reference current range of 1 - 3 A on the load variation 7 Ω and 12 Ω. The test results show the actual current waveform of the inverter output is able to follow the reference current changes. Inductor value that not suitable and the effect of switching cause the ripple is still happening. The higher the output voltage of the inverter will result in the total current harmonic distortion becoming smaller.

Harmonic reduction using a novel multipulse AC-DC converter

2018 ◽  
Vol 15 (4) ◽  
pp. 520-530 ◽  
Author(s):  
Rohollah Abdollahi
Keyword(s):  
Power Quality ◽  
Harmonic Distortion ◽  
Pulse Number ◽  
Main Concern ◽  
Content Type ◽  
Current Harmonics ◽  
Harmonic Reduction ◽  
Light Load ◽  
Simulation Results ◽  
The Cost

Purpose For direct torque controlled induction motor drives, an effective solution to eliminate harmonics is the use of multipulse alternating current (AC)-direct current (DC) converters. Many researchers have used different configurations based on 24- and 30-pulse rectifications for improved power quality. However, the total harmonic distortion (THD) of AC mains current with these topology is more than 4 per cent when operating at a light load. For mitigating the THD problems observed in the input currents, Abdollahi propose 40-, 72- and 88-pulse AC-DC converters, while the power quality enhancement was the main concern. It is known that by increasing the number of pulses further results in reduction in current harmonics, but this is accompanied by an increase in cost and complexity. In this context, the purpose of this paper is to design a new delta/hexagon transformer based 36-pulse AC-DC converter for harmonic reduction without increasing the cost and complexity. Design/methodology/approach The proposed converter consists of two paralleled 18-pulse AC-DC converters involving a nine-phase shifted uncontrolled diode bridges with an interphase transformer circuit. Findings In this paper, the proposed scheme is simulated by matrix laboratory (MATLAB)/SIMULINK considering different loading scenarios. The simulation results show that the proposed scheme improves the power quality indices and satisfies the The Institute of Electrical and Electronics Engineers (IEEE)-519 requirements at the point of common coupling. Also, a laboratory prototype is implemented using the proposed design, and the experimental results confirm the simulation results under different loading conditions. Originality/value The proposed solution is a tradeoff among the pulse number, the transformer platform, the complexity of the scheme and the cost. The proposed scheme has an optimized configuration in this regard.

Multi-objective TMA management optimization using the point merge system

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ramazan Kursat Cecen
Keyword(s):  
Mathematical Model ◽  
Mixed Integer ◽  
Optimization Approach ◽  
Multi Objective Optimization ◽  
Content Type ◽  
Multi Objective ◽  
First Come First Serve ◽  
Management Optimization ◽  
The Mathematical Model ◽  
Single Objective

Purpose The purpose of this study is to provide conflict-free operations in terminal manoeuvre areas (TMA) using the point merge system (PMS), airspeed reduction (ASR) and ground holding (GH) techniques. The objective is to minimize both total aircraft delay (TD) and the total number of the conflict resolution manoeuvres (CRM). Design/methodology/approach The mixed integer linear programming (MILP) is used for both single and multi-objective optimization approaches to solve aircraft sequencing and scheduling problem (ASSP). Compromise programming and ε-constraint methods were included in the methodology. The results of the single objective optimization approach results were compared with baseline results, which were obtained using the first come first serve approach, in terms of the total number of the CRM, TD, the number of aircraft using PMS manoeuvres, ASR manoeuvres, GH manoeuvres, departure time updates and on-time performance. Findings The proposed single-objective optimization approach reduced both the CRM and TD considerably. For the traffic flow rates of 15, 20 and 25 aircraft, the improvement of CRM was 53.08%, 41.12% and 32.6%, the enhancement of TD was 54.2%, 48.8% and 31.06% and the average number of Pareto-optimal solutions were 1.26, 2.22 and 3.87, respectively. The multi-objective optimization approach also exposed the relationship between the TD and the total number of CRM. Practical implications The proposed mathematical model can be implemented considering the objectives of air traffic controllers (ATCOs) and airlines operators. Also, the mathematical model is able to create conflict-free TMA operations and, therefore, it brings an opportunity for ATCOs to reduce frequency occupancy time. Originality/value The mathematical model presents the total number of CRM as an objective function in the ASSP using the MILP approach. The mathematical model integrates ATCOs’ and airline operators’ perspective together with new objective functions.

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