Current Mode Control Research Articles

Design and Simulation of Supercapacitor Energy Storage System

STATCOMs are widely used to enhance power system stability. They can exchange reactive power with the power system, but they have limited ability to exchange real power because they don’t include energy storage devices. STATCOMs coupled with energy storage devices such as batteries have been introduced to improve their ability to exchange real power. However, batteries have a limitation in their maximum deliverable power because of the slow chemical process required to release their energy. The trend now is to use supercapacitor energy storage systems "SCESS" as energy storage for STATCOMS. Supercapacitors have lower energy storage but higher power exchanging capability compared to batteries. This paper presents the analysis, design, and control of a supercapacitor energy storage system (SCESS) for a STATCOM. A peak current mode controller is used to control the SCESS system. Simulation results of the SCESS system are presented which indicate excellent performance of the proposed SCESS system.

Nonlinear Control Structure of Grid Connected Modular Multilevel Converters

This paper implements nonlinear control structure based on Adaptive Fuzzy Sliding Mode (AFSM) Current Control and Unscented Kalman Filter (UKF) to estimate the capacitor voltages from the measurement of arm currents of Modular Multilevel Converter (MMC). UKF use nonlinear unscented transforms in the prediction step in order to preserve the stochastic characteristics of a nonlinear system. In order to design adaptive robust control strategy and nonlinear observer, mathematical model of MMC using rotating d-q theory has been used. Digital time-domain simulation studies are carried out in the Matlab/Simulink environment to verify the performance of the overall proposed control structure during different case studies.

Decoupled average model-based sliding mode current control of LC-filtered inverters in rotating frame

Recently, LC-filtered inverter has been a trendy research object towards the efficient exploitation and use of sustainable energy sources. The nested control scheme of the system includes a voltage control loop and a current one, which can be developed on the rotating frame. The conventional PI controller is employed for the outer loop voltage controller and it performs effectively. However, the PI current controller introduces delay to the system and overshoot occurs frequently due to the influence of nonlinear load. This paper proposes a novel method of decoupled average model-based sliding mode current control performing faster response and better tracking performance of the desired current. Besides, the comprehensive model of the nonlinear load is applied to examine the robustness of the proposed control scheme. This method is developed on the average model, fixed-frequency PWM can therefore be used to modulate the inverter. The novel method is compared with a conventional PI current controller. Offline simulation on MATLAB/Simulink and real-time simulation using Opal-RT experimental platform prove the advantages of the proposed current controller considering critical scenarios with the nonlinear load.

Design and Analysis of a Three-Phase Interleaved DC-DC Boost Converter with an Energy Storage System for a PV System

This paper describes a groundbreaking design of a three-phase interleaved boost converter for PV systems, leveraging parallel-connected conventional boost converters to reduce input current and output voltage ripple while improving the dynamic performance. A distinctive feature of this study is the direct connection of a Li-Ion battery to the DC link, which eliminates the need for an additional charging circuit, which is a departure from conventional approaches. Furthermore, the combination of an MPPT controller and a closed-loop fuzzy controller with a current control mode ensures accurate switching signal generation for all three phases. The meticulously tuned system exhibits a remarkably low ripple content in the output voltage, surpassing calculated values, and demonstrates a superior dynamic performance. The investigation extends to a comprehensive analysis of losses, encompassing inductor copper loss and semiconductor conduction loss. In all scenarios, the converter exhibits an efficiency exceeding 93%, highlighting its robust performance as an effective solution for PV systems.

A New Double-Switch SEPIC-Buck Topology for Renewable Energy Applications

In addition to their conventional use in electric motor drives, DC-DC converters have a variety of other uses, such as energy storage, energy conversion, cyber security systems, uninterruptible power supplies, and renewable energy systems. An innovative DC-DC converter is suggested in this article. Designing a new, high-gain DC-DC converter scheme known as a double-switch SEPIC-buck converter (DSSB) is possible after making some adjustments to the SEPIC converter that is currently known in accordance with accepted techniques. The output voltage magnitude of the proposed converter is either larger than or less than the input voltage magnitude and is the same sign as the input voltage. According to the theoretical and analytical study that has been supported by the real-world application, high voltage gain, low switching stress, and low inductor current ripple are the main characteristics of the proposed DSSB converter. The related small-signal model was also used to build the closed-loop system. The frequency response and output voltage behavior were investigated when the input source voltage abruptly changed as a step function. Based on the comparison study with other DC-DC converters, the DSSB converter outperforms currently known DC-DC converters such as Buck, SEPIC, Boost, Buck-Boost, and other SEPIC converter topologies in terms of voltage gain, harmonic content, normalized current ripple, dynamic performance, and efficiency. Additionally, the frequency response and control of the proposed converter using an alternate current (AC), small-signal, analysis-based, current-mode control technique are both provided. Thus, the DSSB is regarded as safe in overcurrent situations because of the small-signal analysis with the current control strategy. As a result of the verification of the proposed control technique, the resistance to changes in the DSSB parameters, improved dynamic performance, and higher control accuracy are further advantages of current-mode control based on small-signal analysis over other control approaches (PI controllers). Finally, the experimental and simulation results from Simplorer 7 and MATLAB/Simulink are used to validate the findings of the analytical and comparative investigation.

Averaged model of a buck DC–DC converter for single-loop description of current-mode control

Averaged model of a buck DC–DC converter for single-loop description of current-mode control

Improving the Control Strategy of the DVR Compensator Based on an Adaptive Notch Filter with an Optimized PD Controller Using the IGWO Algorithm

One of the objectives of electrical distribution networks is to provide customers with access to high‐quality electricity. Because any disruptions in these systems result in voltage disorders, different devices are employed to offset these disruptions on consumers who are more susceptible. One of the most important and contemporary pieces of equipment that is connected in series with the network is dynamic voltage restoration (DVR), which shields delicate loads from network voltage issues by injecting the proper voltage. This article presents a DVR control scheme optimized with improved grey wolf optimization (IGWO) that uses a proportional derivative (PD) controller and adaptive notch filter (ANF). The output LC filter’s resistance has been removed, and the control system has actively engaged in oscillation damping in order to accelerate dynamic responsiveness and lower system losses. The major component of the voltage, which comprises its frequency, amplitude, and phase, is extracted using ANF. The capacitor current of the output filter in this structure is fed back to the control system and from the current mode control in the inner loop to boost stability. Owing to the occasionally complex dynamic behavior in distribution networks, particularly during a fault, the system’s frequency response has been altered and response speed has been accelerated using the PD controller. This kind of controller is distinguished by its accurate functioning in the presence of frequency deviations and its swifter dynamic reaction in the face of voltage swell and sag. In order to improve the THD and voltage sag indicators of the sensitive load, the PD coefficients were adjusted using the IGWO algorithm. As a consequence, the simulation results demonstrated that the suggested controller performed better than traditional controllers.

Multiple-Mode Current Control for a Hybrid-Excitation Axial Flux Switching Permanent Magnet Motor Considering Driving Cycles

This paper proposes a multiple mode current (MMC) control for hybrid-excitation axial flux switching permanent magnet (HE-AFSPM) motors considering driving cycles. To satisfy the diverse and compound control demands in multiple operating condition of EVs, the model predictive control is adopted, and multiple current vector prediction method including <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> -axis current, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">q</i> -axis current, and DC excitation current is proposed to optimize current assignment ratio, enhance the dynamic performance, and improve motor efficiency. An online optimization method considering four operating conditions in two speed domains is demonstrated, where the different current assignment function and constraint is applied in each operating condition, and the optimal assignment currents are obtained effectively by the Lagrange multiplier method online in real time. Finally, to verify the feasibility of the multiple-mode control method, a prototype motor is built and tested. And, the motor performances in the different driving modes are investigated in detail. The experimental results reveal that the proposed control method can offer an effective control for the HE-AFSPM motor, where multi-mode operations are indispensable.

Experimental Variable Band Hybrid Current Mode Control for High Power High Frequency Inverter in Electro Surgical Applications

Experimental Variable Band Hybrid Current Mode Control for High Power High Frequency Inverter in Electro Surgical Applications

Artificial Intelligence-Enhanced Peak Current Mode Control for Enhanced Power Regulation in High Power High Frequency Electrosurgical Generators

Artificial Intelligence-Enhanced Peak Current Mode Control for Enhanced Power Regulation in High Power High Frequency Electrosurgical Generators

Optimal Tuning of Current Mode Controllers by Mapping to State-Feedback with Integral for Fuel Cell Integrated Boost Converter

Optimal Tuning of Current Mode Controllers by Mapping to State-Feedback with Integral for Fuel Cell Integrated Boost Converter

Comparative Study of the Normalized-Error-Based Control and Traditional Current-Mode Control for a Sixth-Order Boost Converter

Comparative Study of the Normalized-Error-Based Control and Traditional Current-Mode Control for a Sixth-Order Boost Converter

Current-mode PID controllers employing commercially available active components

This work describes two current-mode (CM) PID controllers using only two commercially active components, namely, current feedback operational amplifier (CFOA), and four passive components, i.e. two capacitors and two resistors. They have appropriate output and input impedance values, allowing them to be utilized in cascade connections without requiring a buffer circuit. Since all capacitors are grounded, it is suitable for integrated circuit (IC) technology. Moreover, the controllers can be easily modified to operate in voltage-mode (VM), transimpedance-mode (TIM), and transadmittance-mode (TAM) PID controllers. Using 0.18 µm CMOS parameters and the PSPICE program, the proposed circuits are simulated to verify the theoretical behavior. To demonstrate the viability of the circuits, experimental tests using commercially available AD844 integrated circuits are performed. The suggested PID circuits are alsoexperimental tested in a closed-loop system as an example.

A novel cat swarm optimization‐based fuzzy PI controller for improving dynamic response of converter

AbstractNowadays, the use of fuel cells in various applications has become very widespread. Some of their most important applications are in electric vehicles (EVs) and local off‐grid power systems. An EV works as an electric motor that burns a mixture of fuel and gases to generate electricity. One of the challenges with fuel cells is the slow dynamic response to load power changes. In the past few decades, the modeling and control of DC‐DC converters have undergone extensive research and development. However, the error, settling time, and peak overshoot performance are not reduced by the robust nonlinear controller and current mode controller. To overcome these problems, quantile regressive extreme seeking cat swarm optimized Mamdani fuzzy PI controller (QRESCSO‐MFPIC) approach is developed. The goal of the QRESCSO‐MFPIC approach is to reduce the integral time absolute error (ITAE) for tuning the fuzzy PI controller. Initializing the fuzzy PI controller parameter is an input in the QRESCSO‐MFPIC approach. For every parameter value, the fitness function is determined and quantile regression analysis is carried out. The efficiency of the QRESCSO‐MFPIC approach is measured by evaluating the settling time and peak overshoot. Tuning of the PI controller is carried out with cat swarm optimization (CSO) and particle swarm optimization (PSO) based on the objective function of ITAE. The result analysis shows that the QRESCSO‐MFPIC approach improves the efficiency of an optimized Fuzzy PI controller compared to the existing methods. Peak overshoot reduction and settling time are improved through the QRESCSO‐MFPIC approach than the proportional integral particle swarm optimization controller (PI‐PSO).

A bridgeless configured asymmetrical alternating current–direct current converter‐based isolated single‐stage electric vehicle battery charger with supply side power factor enhancement

AbstractAn approach is presented to employ two different types of converters in bridgeless configuration for supply side power factor enhancement of the system. The isolated single‐stage electric vehicle battery charger uses two different converters in a bridgeless configuration to extract the advantages of both converters for supply‐side power factor enhancement. For the negative and positive semi‐cycles of the supply voltage, the power factor‐enhanced asymmetrical alternating current–direct current converter utilises a fourth order single‐ended primary‐inductor converter and a second order buck‐boost converter, respectively. The use of single‐ended primary‐inductor converter and buck‐boost converter in bridgeless configuration reduces the net order of the system with respect to conventional bridgeless‐single‐ended primary‐inductor converter schemes. The buck‐boost converter also needs the supply‐side filter to eradicate the unwanted harmonics in the supply current which increases the order of the system. The usage of both converters presents many benefits like input inductance of the single‐ended primary‐inductor converter can be utilised as a filtering element with a capacitor for the buck‐boost converter. The anti‐parallel diode conduction operation of both switches facilitates the elimination of extra reverse feed diodes (generally used in bridgeless schemes). The single‐stage charger itself comes with the benefit of elimination of extra stages and thus the losses associated with it. The presented charger also witnesses the elimination of the rectifier due to usage of bridgeless configuration. The isolated single‐stage electric vehicle battery charger is also garnished with electrical isolation which adds to the safety standard of the system. To attain power factor enhancement, the asymmetrical alternating current–direct current converter functions in discontinuous current conduction mode in the present work. The elimination of extra‐stages (with respect to two stage charger), a filter, a rectifier, two extra reverse‐feeding diodes, one voltage sensor, one current sensor (with respect to continuous current conduction mode), and electrical isolation not only makes the system compact and safer but also makes the system cheaper. Elaborated mathematical modelling and stability analysis of the presented alternating current–direct current converter using a pole‐zero map and bode plot have been included in the article. The prototype and MATLAB/Simulink model of isolated single‐stage electric vehicle battery charger system with discontinuous current conduction mode control has been built and results of both prototype and MATLAB/Simulink are deployed to verify isolated single‐stage electric vehicle battery charger system's performance during dynamic and steady‐state conditions.

Modeling and design of a photovoltaic‐fed single‐ended primary‐inductor converter for maximum power point tracking with current mode control

SummaryIn this work, the control of a Single‐Ended Primary‐Inductor Converter (SEPIC) supplied from a photovoltaic energy source and linked at its output to a DC current sink is addressed. The system is used for maximum power point tracking under varying environmental conditions. A strategy based on two loops of control is considered. A peak current mode controller is used for the inner loop, and a Proportional‐Integral (PI) controller is used for the outer voltage loop. Then, a comprehensive time‐domain and frequency‐domain modeling of the inner loop is theoretically addressed and then verified by the switched model of the system implemented in PSIM© software. The obtained results show that the system exhibits accurate tracking of the desired PV voltage while guaranteeing a fast maximum power point tracking under sudden changes in the environmental conditions. The mathematical modeling, design procedures, and the numerical simulations are validated using experimental results obtained from a laboratory prototype.

Robust and efficient control strategy for single-phase two-stage PV grid-tied system with improved power quality

In the last couple of decades, the integration of photovoltaic (PV) systems with the utility grid has gained significant attention due to its potential to harness renewable energy and contribute to sustainable power generation. However, the integration of the PV system into the grid leads to issues related to power quality and system stability under varying solar irradiation, dc offset, and distorted grid conditions. Therefore, this paper focus on the robust and efficient control of a single-phase, two-stage PV grid-tied system to improve power quality and stable system operation under abnormal grid conditions. These objectives can be achieved using the synchronization method, dc link voltage control, and grid current control. The hybrid PLL is proposed in this paper for synchronization and to mitigate the effect of dc offset and lower-order harmonics in the estimated phase and frequency. Further, the sliding mode voltage controller and integral sliding mode current controller are proposed for dc link voltage regulation and grid current tracking. The stability of voltage and current control loops is analyzed using the Lyapunov stability theory. Furthermore, the proposed schemes are validated using MATLAB simulation and experimental analysis. The proposed approach outperforms conventional methods and exhibits better disturbance rejection capability under both dynamic and steady-state conditions, making it a robust and efficient control strategy for grid-tied systems.

A Nonlinear Multimode Controller for Seamless off-Grid of Energy Storage Inverter Under Unintentional Islanding

A nonlinear multimode controller (NMC) is proposed to achieve the whole process seamless off-grid of energy storage inverter (ESI) from the grid-connected state of current control mode (CCM) to the islanded state of voltage control mode (VCM) under unintentional islanding. Based on the presented design idea of intelligent equivalent substitution, NMC is composed of multimode voltage controller (MVC), multimode power compensator (MPC) and multimode current controller (MCC). MVC can control load voltage in islanding and maintain manipulated variables of load current in other modes. MPC can compensate the power flowing into grid and help inner loop reference value achieve the smooth drop, and also compensate for load current variation during grid-connection. MCC can track the given current during grid-connection and make MPC quickly obtain the compensation of load power variation. The reference values of inner loop are logically split into the output of MVC, MPC and MCC, so that the manipulated variables can be combined nonlinearly to achieve seamless off-grid of ESI under unintentional islanding. This paper also analyzes the ESI stability with NMC during the off-grid process, and analyzes the relationship between manipulated variables by simulations. Finally, the correctness and effectiveness of proposed NMC are verified by experiments.

Generation of an Electron Beam in a Source with a Plasma Emitter in the Combined Current Control Mode

Generation of an Electron Beam in a Source with a Plasma Emitter in the Combined Current Control Mode

Performance Analysis of Switched Reluctance Motor by Using Closed Loop Current Control Technique

This paper presents the performance analysis of an 6/4 3-phase switched reluctance motor in terms of current, flux, torque and speed. When the speed of the motor is low the current rises quickly. If the speed is large the increase in current is low. In low-speed region, the current can be controlled by using chop/hysteresis current control mode. In this mode a voltage of +Vdc and -Vdc is applied in such way the current is limited to a band. The bands can design around the reference value of current. The upper and lower bands can be designed based on the reference current. After the base speed we have to maintain current, current can’t increase quickly because speed becomes large, so in this region instead of keeping current constant the power is to be considered constant. When the speed is large this mode is not preferable. So still we have to maintain the power current has to build up, so we switch little earlier that angle is called advance angle. Angle by which voltage application is advanced that angle is the advance angle. The advance angle control can be used in such way that the current increase will happen in the lower inductance region only. The advancing of angle can be increased up to certain angles only i.e up to the lower value of inductance minimum point. The simulation has been carried out for 6/4 3-phase switched reluctance motor using MATLAB/ Simulink by applying closed loop current control technique. The detailed control of SRM for different speed modes has been carried out and the analysis of results demonstrated.