Power Circuit Parameters Research Articles

Adaptive Sliding-Mode Controller for a Zeta Converter to Provide High-Frequency Transients in Battery Applications

Hybrid energy storage systems significantly impact the renewable energy sector due to their role in enhancing grid stability and managing its variability. However, implementing these systems requires advanced control strategies to ensure correct operation. This paper presents an algorithm for designing the power and control stages of a hybrid energy storage system formed by a battery, a supercapacitor, and a bidirectional Zeta converter. The control stage involves an adaptive sliding-mode controller co-designed with the power circuit parameters. The design algorithm ensures battery protection against high-frequency transients that reduce lifespan, and provides compatibility with low-cost microcontrollers. Moreover, the continuous output current of the Zeta converter does not introduce current harmonics to the battery, the microgrid, or the load. The proposed solution is validated through an application example using PSIM electrical simulation software (version 2024.0), demonstrating superior performance in comparison with a classical cascade PI structure.

Research on Super-Twisting Sliding Mode Voltage Regulation Control of Electric Spring

The traditional control of electric spring (ES) is too complex and lack of robustness, as well as the chattering phenomenon and control accuracy of traditional sliding mode control, a second-order terminal sliding mode control based on super twisting algorithm is proposed. In this paper, the phase plane method is used to establish the mathematical model of ES, solve the state space equation, and regard the AC power supply as a simplified error analysis. Then a second-order sliding mode controller is proposed. The controller parameters are solved to obtain the second-order sliding mode control rate, and the stability is verified. Finally, three groups of comparative simulation experiments were set up by Matlab/Simulink, and the effectiveness of the model was verified by considering the voltage mutation caused by the change of power supply and circuit parameters. Compared with the traditional control method, the proposed control strategy not only ensures the voltage stability, but also improves the control accuracy and the performance of suppressing sliding mode chattering, and has better dynamic response ability.

Active rectifier with a fixed modulation frequency and a vector control system in the mode of bidirectional energy flow

Goal. Creation of a vector control system with improved characteristics for an active rectifier-voltage source operating in the bidirectional energy flow mode with a with a fixed modulation frequency. Methodology. The physical prerequisites for the active rectifier - voltage source operation in the system of a medium-power frequency electric drive are considered. A vector control system with a fixed modulation frequency is constructed, the principles of forming the signals acting in it and the influence on its operation of the converter power circuit parameters and the power consumed by it are considered. Mathematical modeling of the converter with the developed control system in MATLAB/Simulink made it possible to verify the correctness of the operation of the power circuit and the control system. Results. A new structure of a vector control system operating with a fixed modulation frequency is proposed, and the performance characteristics of the circuit in a wide range of changes in the magnitude and sign of the output power are obtained. The advantages of the new control system over the existing ones are shown. Originality. The physical prerequisites for the functioning of the power scheme and the vector control system of the ARVS proposed by the authors with a fixed frequency of modulation, the principles of forming the signals operating within it are considered in detail. Practical significance. New structure of the vector control system operating with a fixed modulation frequency is proposed and the advantages of the new control system over the existing ones are shown.

Steady-State and transient assessments of integral back-stepping current controllers in high-voltage direct current transmission systems

In the last five decades, proportional-integral (PI) controller remains dominant in control of high-power converters in industrial and utility power systems despite its bandwidth, hence, the performance is coupled to power circuit parameters and degrades in parts of operating range. Consequently, further mitigation measures such as fine-tuning or loop reshaping might be needed. In contrast, integral back-stepping (IBS) decouples controller bandwidth and performance from the system parameters; hence, leads to consistent performance throughout the operating range and simplifies tuning of controllers with complex structures with multiple loops. Therefore, this paper investigates the suitability of IBS for implementation of inner current controllers of the voltage source converter (VSC)-based high-voltage direct current (HVDC) transmission systems. The paper presents step-by-step synthesis of back-stepping current controller and supporting theoretical bases, and assesses its performance against the conventional PI current controller. Theoretical analysis and discussions and comparative simulations reveal that the characteristics of IBS technique enjoys unique characteristics: decouples the controller gains from the converter parameters; restricts closed loop poles to real axis; and exhibits larger closed loop bandwidth than the PI counterpart. It has been shown that the gains of IBS current controllers are explicitly specified in terms of the desired natural frequency and damping ratio, which are advantageous compared to that of the PI equivalent, in which the closed loop bandwidth are limited by converter parameters. For ease of illustration of similarities and differences, only inner current controllers of the converter stations were designed using integral back-stepping technique and compared against PI equivalents. The outer control loops such as dc link voltage, active and reactive power controllers are designed based on proportional-integral controllers. MATLAB-SIMULINK models of the point-to-point VSC-HVDC system, in which the current controllers implemented using integral back-stepping and proportional-integral controllers (active/reactive power and DC link voltage controllers) have been developed and subsequently used for performance comparison. Results of the one-to-one comparison show that the integral back-stepping current controller can match and even outperform its proportional-integral equivalent during normal and abnormal conditions, including current limitation during ac faults. Selected experiments conducted on grid connected voltage source converter that employs IBS current controller have confirm its viability.

Passivity-Based Design of Grid-Side Current-Controlled $LCL$-Type Grid-Connected Inverters

The frequency-domain passivity theory offers an effective way to assess the stability of inverters connecting to complex grid conditions, e.g., inductive grid, capacitive grid, and system comprising multiple inverters. In this article, an admittance model for the grid-side current-controlled $LCL$ -type inverter with capacitor voltage feedforward active damping (CVF-AD) is built to facilitate the passivity-based stability assessment and controller parameter design. Especially, it is found that if the antiresonance frequency of the inverter-side inductor and the filter capacitor is designed in a certain region, i.e., $(\text{0.66}f_c + \text{0.034}f_s, \text{0.22}f_s)$ , all frequencies’ passive output admittance of the inverter can be achieved via a modified CVF-AD scheme with simple digital implementation. Thanks to the proposed methods, the inverter can be connected to the grid regardless of the grid impedance, which means a robust plug-and-play functionality suitable for microgrid applications. In addition, the controller parameters are analytically designed; time-consuming iterations are, hence, avoided. The allowable tolerance of power circuit parameters for a valid controller parameter design is as high as 64% or more. The validity of the theoretical analysis and effectiveness of the proposed method are verified by using experimental results on a laboratory prototype.

Soft Switching of Full-Bridge DC-DC Buck Converter

The conventional Bidirectional Full-bridge dc -dc converter is inefficient and may not be practical for the low power applications. This paper specifies an efficient DC-DC Converter that avoids power losses by using soft switching techniques like Zero Voltage Switching and Zero Current switching. The soft switching of Bidirectional Full-bridge DC-DC Converter operates as a buck converter when the power is positive and as a boost converter when the power flow is negative. Applications of soft switching Bidirectional Full-bridge DC-DC Converter are uninterrupted power supplies (UPS), distribution Systems, battery charger circuits, telecom power supplies, computer power systems. Detailed analysis of the converter is carried out in buck mode to obtain relations between the power circuit parameters. Based on the analysis, control schemes are described to operate the converter. The proposed full bridge DC-DC converter is simulated in Buck mode using MATLAB /SIMULINK.

Design and Selection of Power Circuit and Control Parameters for DSTATCOM

This paper presents the proper design and selection of power circuit and control parameters of VSI based DSTATCOM for compensation of reactive power in a radial distribution systems, feeding power to crucial loads of an industrial, commercial and residential systems. The study of radial distribution system is analyzed in terms of electrical power system of institute, power consumption pattern and tariff related issues. Some conclusions were made to improve the system performance in terms of power factor and reduction in tariff. The DSTATCOM performance depends on the calculation of the reference source currents that generate the gating pulses of the VSI.

An Intelligent Wheelset Spinning Detection System in a Direct Current Traction Drive

A spinning detection method of a locomotive wheelset in a dc traction drive and its implementation on the basis of intelligent processing of measuring data of the drive control system is considered. An increase in the amplitudes of the low-frequency harmonics of the voltage sensor output signal on the locomotive power circuit elements is used as a sign of loss of motion stability of the wheelset due to reaching the threshold wheel–rail adhesion. For automatic multilevel identification of spinning modes, a random forest algorithm-based classifier is used. The results of the analysis of the control power circuit parameters preindicated by experts show the high sensitivity and accuracy of the proposed intelligent spinning detection system.

Output Characteristics and Circuit Modeling of Wiegand Sensor.

A fast magnetization reversal in a twisted FeCoV wire induces a pulse voltage in a pick-up coil wound around a wire. The Wiegand sensor is composed of this magnetic wire and the pick-up coil. As the output pulse voltage does not depend on a changing ratio of the applied magnetic field to switch the magnetization of the wire, the Wiegand sensor is used for to perform rotation and other detections. Recently, the Wiegand sensor has attracted significant attention as a power supply for battery-less operation of electric devices and for energy harvesting. In this study, we propose a concept of obtaining an intrinsic pulse voltage from the Wiegand sensor as its power source, and demonstrate its effectiveness in circuit simulation. The equivalent circuit for the Wiegand sensor is expressed by the intrinsic pulse voltage, internal resistance, and inductance of the pick-up coil. This voltage as a power source and circuit parameters are determined by MATLAB/Simulink simulation. The output voltage calculated using the equivalent circuit of the Wiegand sensor agrees with the experimentally measured results.

Design and Simulation of Three Level Neutral Point Clamped Inverter Fed Induction Motor Drive

The objective of the project is to obtain some proficiency in building converters to control speed of medium voltage induction motors. The thesis covers summary of literature surveyed, selection of a topology of converter for design, design of a 3-Level NPC inverter power circuit and FOC parameters. The entire system has been simulated using PSIM software for verification of design. Results obtained are presented. Results prove that the understanding of the student (author) is satisfactory. A low voltage 10kW squirrel cage induction motor has been chosen as the load to converter for design and simulation. Future work may be design of complete control circuits implementing FOC, building complete hardware and testing the small motor chosen.

Study on volt-ampere characteristics of spark discharge for transistor resistor pulse power of EDM

Electrical discharge machining (EDM) is widely used in aerospace industry and difficult-to-machine materials field. But the research on machining mechanism is insufficient and it has become a bottleneck of restricting its further development. In this paper, spark discharge self-sustaining conditions, the effects of pulse power circuit parameters on gap volt-ampere characteristics of EDM, formation of maintaining voltage of spark discharge, frequency and amplitude fluctuation of high-frequency components of maintaining voltage, and stability of spark discharge state are studied. Forming process of maintaining voltage of spark discharge is analyzed through discharge main circuit structure of transistor resistor pulse power. Influence of current-limiting resistor on maintaining voltage of spark discharge is also studied. The effect law of current-limiting resistor on oscillation frequency of maintaining voltage of spark discharge is obtained through spectrum analysis of maintaining voltage of spark discharge by methods of fast Fourier transform (FFT). Gap spark discharge control system is established through discharge circuit model of transistor resistor pulse power and the gap of EDM is replaced by spark discharge gap equivalent form. Input of the control system is the voltage of pulse power and its output is the gap voltage. Influence of current-limiting resistor on stability and response speed of the system is analyzed. The above research is important for revealing the mechanism of EDM, maintaining the stability of spark discharge, and guiding the design of pulse power and selection of processing parameters.

Двухканальный драйвер силовых ключей с параллельным резонансом в цепи затвора

The well-known scheme of a one-channel power switch driver with parallel resonance in gate circuit (PRD) is considered and its merits and demerits in comparison with the standard drivers are given. A new type of PRD drivers for control of FETs, combined and composite transistors is proposed and described. The proposed driver performs opposite-phase control of two MOSFETs with induced channels and can be used in advanced static converters of a megahertz frequency range. The two-channel PRD driver has a number of advantages over the previously proposed driver schemes. In comparison with traditional drivers it allows significantly smaller gating losses and a higher switching frequency to be achieved. In comparison with quasi-resonant circuits, the two-channel PRD opens the possibility to have a considerably lower power and cost of the semiconductor amplifier. In comparison with one- channel drivers better performance characteristics and more stable operation were obtained owing to the use of a resonant-circuit three-winding coil and mutual compensation of the nonlinearity of the transistors’ input capacitances. The above-mentioned nonlinearity is compensated due to the transistor input capacities being connected in coupled resonant circuits in an opposite-phase manner. As a result, a close to a sine wave shape of the gate voltage is obtained. The duty cycle for each switch is a little bit smaller than 0.5. The use of the proposed scheme guarantees that a dead interval of time is secured between the opening instants of switches controlled by a single driver and that the system will have high noise immunity. On the other hand, the two-channel PRD driver has certain shortcomings: it features a fixed duty cycle, a comparatively long switching time, and a noticeable influence of the power circuit parameters on the system operation. In view of these circumstances, it is recommended to use PRD drivers in megahertz frequency range resonance converters with phase and discrete control modes. The functional diagram of a bridge converter with phase control and two-channel PRD drivers is presented, and recommendations on selecting its elements are given. The proposed drivers are supposed to be used mainly for constructing compact converters with a high specific power for portable devices and for electric vehicles.

Methods for Controlling Autonomous DC Systemson the Basis of Switching by Capacitors

The article demonstrates methods for constructing pulse-amplitude (PAM) and pulse-width (PWM) controlled DC systems on the basis of switched-capacitor structures. Represented is the optimal structure of the system of DC electrical power interchanges (SEI), which excludes the use of additional elements. Proposed are the algorithms for controlling SEI transistor keys and their regulating characteristics. Studied are the features of their work and obtained are the equations for calculating the power circuit parameters.

Evaluation and optimization of multi-channel pulsed discharge plasma system for soil remediation

Pulsed discharge plasma is a rapid and high-efficient option for organic pollutants contaminated soil remediation. In order to optimize the coupling of pulsed power supply and plasma reactor, and enhance pollutant removal in soil by pulsed discharge plasma, power circuit parameters and reactor configuration such as adjustable trim capacitance, discharge needle number, and discharge voltage were optimized with respect to energy input, power source efficiency, pollutant degradation, process efficiency, and energy yield. p-Nitrophenol (PNP) was chosen as the model pollutant in soil. The experimental results showed that 90.7% of PNP were degraded under the conditions of adjustable trim capacitance 200 pF, discharge needle number 19, and discharge voltage 18.0 kV, with power source efficiency of 62.5%. The increase of adjustable trim capacitance was beneficial for PNP degradation and process efficiency, but not for power source efficiency and energy yield. Higher PNP degradation efficiency was obtained as more discharge needle numbers were employed, as well as for the power source efficiency and energy yield. Increasing discharge voltage benefited PNP degradation, but went against energy yield. The power source efficiency increased firstly with discharge voltage, and then decreased with further increasing discharge voltage. Furthermore, PNP mineralization was also analyzed.

Modeling, Design and Simulation of Multilevel Inverter Based Active Power Filter

This paper presents mathematical modeling, design and simulation of a three-phase MLI based APF for compensation of current harmonics present in a high voltage system. A PI controller is designed to control DC link voltage. Complete design methodology for the selection of power and control circuit parameters is developed. The simulation results show that MLI based APF eliminates harmonics in high voltage system.

전력설비의 안정한 운용을 위한 3상 능동전력필터의 강인한 내부모델제어

A new simple control method for active power filter, which can realize the complete compensation of harmonics is proposed. In the proposed scheme, a model-based digital current control strategy is presented. The proposed control system is designed and implemented in a form referred to as internal model control structure. This method provides a convenient way for parameterizing the controller in term of the nominal system model, including time-delays. As a result, the resulting controller parameters are directly set based on the power circuit parameters, which make tuning of the controllers straightforward task. In the proposed control algorithm, overshoots and oscillations due to the computation time delay is prevented by explicit incorporating of the delay in the controller transfer function. In addition, a new compensating current reference generator employing resonance model implemented by a DSP(Digital Signal Processor) is introduced. Resonance model has an infinite gain at resonant frequency, and it exhibits a band-pass filter. Consequently, the difference between the instantaneous load current and the output of this model is the current reference signal for the harmonic compensation.

Research on the Bi-directional DC-DC Conversion Characterization of Ultra -capacitor Energy Storage System

To ensure the stability of load voltage, a bi-directional DC-DC converter is usually required in the power buffer application of the ultra-capacitor energy storage system. In this paper, non-isolated Buck-Boost bi-directional DC-DC converter is analyzed to improve the terminal voltage performances. In the light of the requirements of constant terminal voltage when positive and negative bi-directional power flows, the optimal design of power circuit and control parameters increases the operation stability of the whole ultra-capacitor energy storage system. Furthermore, it decreases the fluctuation of load voltage and raises the utilization rate of ultra-capacitors’ energy reserve.

On the analysis of electric arc process stability in plasma systems of ignition with allowance for GTE combustion chamber parameters

An approach to the analysis of electric arc process stability in plasma systems of ignition is considered depending on the ignition system power circuit parameters, speed of plasma-generating air, and combustion chamber inlet pressure. Also solved is the problem on determination of the calculated value of the maximum admissible speed of plasma-generating air that corresponds to the critical regime of stable arcing in plasma spark plug at the GTE start.

Cooperative Control of Active Power Filters in Power Systems without Mutual Communication

The procedure for calculating controller parameters of the APFs implemented into a multibus industrial power system for harmonic voltage mitigation is presented. The node-voltage-detection control strategy is applied and the basic controller parameters are found under the condition that the demanded THD factors at the buses where the APFs are placed will be obtained. A cooperative control of several APFs without mutual communication is proposed, simulated, and experimentally verified. By tuning the controller gains without considering the power circuit parameters, all APFs used tend to share harmonic load currents approximately equally regardless of the operation modes of the nonlinear loads in different parts of the power system.

경두개 자기자극장치의 치료자극 펄스

In this study, I presented power control unit with potential use in the magnetic stimulation of biological systems. The effect of the magnetic stimulation depends on the geometry and orientation of the induced electric field as well as on the current pulse waveform delivered by the stimulator coil. TMS is achieved from the outside of the head using pulses of electromagnetic field that induce an electric field in the brain. There are numerous possibities in the applications TMS, such as diagnosis and therapy through the brain stimulation. These factors are very important to define the equipment requirements and characteristics in that the topology of the power supply and the size and geometry of the coil. The proposed solution is the generation of current pulses with variable amplitude and duration, according to a user defined input. Another solution is the topology that uses elements to store and transfer energy from the power source to the load. In addition to proposed topology, an adequate control strategy and right set of the power circuit parameters made possible to obtain unipolar waves and bipolar waves.