Switching Losses Research Articles

A novel maximum power point tracking with hybrid control algorithm for automotive thermoelectric generator system.

To dynamically track the maximum power of an automotive thermoelectric generator (ATEG) system in real-time, this study introduces a novel maximum power point tracking (MPPT) algorithm that integrates Kalman filtering and fuzzy control. Employing a two-phase interleaved parallel DC-DC boost converter in the MPPT controller effectively reduces current ripple and switch loss. Results demonstrated a significant improvement in tracking time compared to the traditional incremental conductance algorithm, attributed to the elimination of high-frequency components in output power by the Kalman filter. The novel algorithm exhibits enhanced tracking stability through the application of fuzzy control. Ultimately, the tracking accuracy of the novel algorithm surpasses that of the incremental conductance algorithm by 5.2%, achieving an impressive 94.9%. This study, therefore, presents a valuable contribution to a novel MPPT algorithm for precisely and rapidly tracking the global maximum power points of the ATEG system throughout the entire vehicle driving cycle.

A Novel Virtual Space Vector Modulation With Optimized Neutral-Point Voltage Control Capability for Ten-Switch Three-Phase Three-Level Inverter

Ten-switch three-phase three-level inverter (TP-TLI) is receiving more attentions owing to the reduced system cost compared to traditional TP-TLIs. However, it still faces serious neutral-point voltage (NPV) balance problem. This article proposes a novel virtual space vector modulation (NVSVM) with optimized neutral-point voltage control (NPVC) capability. A set of virtual vectors are selected to generate zero NP current. By analyzing the vector synthesis principle over the full modulation areas, a new control degree, which is utilized to optimize the NPVC capability and reduce line voltage THD, is introduced. Besides, a dead time compensation method based on volt-second balance is also given to reduce the switching loss. The NVSVM not only improves the NPVC capability without dc offset and obvious ac oscillations in NPV under full range of modulation index and power factor (PF) conditions, but also reduces line voltage THD and the switching loss. Theoretical analysis shows that the available NP current for the proposed NVSVM is about 2.75 times greater at most than that for traditional VSVM. Simulation and experimental results are given to validate the effectiveness of the NVSVM and control strategies.

Optimal Decoupled Discontinuous Modulation for StatComs Based on the Cascaded H-Bridge Converter

Conventional discontinuous pulse width modulation (DPWM) strategies for cascaded H-bridge static compensators suffer from poor inter-phase capacitor voltage balance control during unbalanced grid voltage conditions. Specifically, the logic-based algorithm that calculates the zero-sequence voltage (ZSV) for discontinuous operation interacts with the closed-loop capacitor voltage control. This paper proposes an optimal DPWM strategy based on a finite-set optimization that chooses the best ZSV candidate that minimizes the control interactions while clamping a converter voltage. Furthermore, the effect of the different ZSV candidates on the switching loss is also considered within the optimization. Extensive experimental study is provided to demonstrate the effectiveness of the proposed approach.

Design of modified reference phase modulation based boost chopper fed fifteen level stepped DC link hybrid converter

A new fifteen-level stepped DC to AC hybrid converter is proposed for Solar Photovoltaic (SPV) applications. A boost chopper circuit is designed and interfaced with the fifteen-level hybrid converters specific to Electric Vehicles’ Brushless DC Motor (BLDC) drive systems. In chopper units, the output of solar panels is regulated and stepped up to obtain the nominal output voltage. In the stepped DC-link hybrid converter configuration, fifteen-level DC-link voltage is achieved by the series-operated DC-link modules with reduced electrical energy compression. From the comprehensive structure, it is anecdotal that the proposed topology has achieved minimum switching and power loss. Elimination of end passive components highlights the merits of the proposed hybrid systems. The reduction of controlled power semiconductor switches and gate-firing circuits has made the system more reliable than other hybrid converters. From the extensive analysis, the experimental setup has reported that 7% reduction in harmonics and a 54% reduction in controlled power switches than the existing fifteen-level converter topologies. Mitigation of power quality issues in the voltage profile of a fifteen-level multilevel hybrid converter is achieved through the implementation of dsPIC digital-controller-based gate triggering circuits.

A Bidirectional Direct AC-AC Resonant SCC

A direct ac-ac resonant switched-capacitor converter (SCC) for both noninverting and inverting output voltages is proposed here, which is suitable for bidirectional power transmission including different applications such as dynamic voltage restorer (DVR), constant voltage regulator (CVR), and constant current regulator (CCR). Zero voltage switching (ZVS) and zero current switching (ZCS) operation conditions are easily realized for its power switches, which effectively reduce the switching losses, as well as the electromagnetic interference (EMI) noise. Consequently, high-frequency operation is possible, which improves the converter power density, in practice. Continuous voltage-gain, transformerless connection of the converter output port to the gird, no commutation problems without using extra components, and improving the electrical specifications are some other advantages of the given resonant SCC. The converter operation principles, its key waveforms and different operational states, its mathematical analysis and normalized state-plane trajectories, simulation results, as well as its design procedure, are also given here, in detail. To verify the given theoretical analyses and simulation results, a 500 W prototype converter for a 2 kW DVR with 220 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rms</sub> nominal output voltage has been implemented successfully, which realizes 96.55% efficiency at its rating power value.

An LLC resonant converter with wide output range fixed frequency PWM control for PEV charging applications

PurposeThis study aims to regarding the application of traditional pulse frequency modulation control full-bridge LLC resonant converters in wide output voltage fields such as on-board chargers, there are issues with wide frequency adjustment ranges and low conversion efficiency.Design/methodology/approachTo address these issues, this paper proposes a fixed-frequency pulse width modulation (PWM) control strategy for a full-bridge LLC resonant converter, which adjusts the gain by adjusting the duty cycle of the switches. In the full-bridge LLC converter, the two switches of the lower bridge arm are controlled by a fixed-frequency and fixed duty cycle, with their switching frequency equal to the resonant frequency, whereas the two switches of the upper bridge arm are controlled by a fixed-frequency PWM to adjust the output voltage. The operation modes of the converter are analyzed in detail, and a mathematical model of the converter is established. The gain characteristics of the converter under the fixed-frequency PWM control strategy are deeply analyzed, and the conditions for implementing zero-voltage switching (ZVS) soft switching in the converter are also analyzed in detail. The use of fixed-frequency PWM control simplifies the design of resonant parameters, and the fixed-frequency control is conducive to the design of magnetic components.FindingsAccording to the fixed-frequency PWM control strategy proposed in this paper, the correctness of the control strategy is verified through simulation and the development and testing of a 500-W experimental prototype. Test results show that the primary side switches of the converter achieve ZVS and the secondary side rectifier diodes achieve zero-current switching, effectively reducing the switching losses of the converter. In addition, the control strategy reduces the reactive circulating current of the converter, and the peak efficiency of the experimental prototype can reach 95.2%.Originality/valueThe feasibility of the fixed-frequency PWM control strategy was verified through experiments, which has significant implications for improving the efficiency of the converter and simplifying the design of resonant parameters and magnetic components in wide output voltage fields such as on-board chargers.

High step up DC–DC converter with low conduction losses and reduced switching losses

AbstractThis article presents a novel high step up converter based on the active switch inductor (ASL) technique for renewable energy source applications. The coupled inductor technique provides an opportunity to increase the gain. The proposed converter exploited the leakage inductors to provide zero current switching (ZCS) turn‐on for both switches. Therefore, there is no need for an auxiliary circuit, which simplifies the structure. Also, all diodes turn off under ZCS, which eliminates the reverse recovery problem and results in reduced switching losses. The energy of the leakage inductor is recycled, and the voltage spike on the switches is limited. In addition, all semiconductor voltage stresses are clamped below the output voltage. Hence, components with lower on‐resistance can be utilized to reduce conduction loss. Because of the reduction in power loss, the efficiency rises to 97.2% at 250 W output power. It also benefits from the current sharing of the interleaved structure. The operating principles, design considerations, and comparison to other topologies are discussed. To verify the effectiveness of the proposed converter, a prototype converter with 250 W of output power, 50 V of input voltage, 500 V of output voltage, and 100 kHz of switching frequency is implemented.

Aplikasi Peralatan Flexible AC transmission Systems (FACTS) Pada Sistem Tenaga Listrik

The power need of South Sulawesi community is increasingly in a row with technology development. At this time, with the lack of new generation and transmission facilities make voltage instability always occur. To relieve it, Flexible AC Transmission System (FACTS) is used, that is, Static Compensator (STATCOM) which its basic operating principles functions as a synchronous voltage source. This research aimed to find out voltage conditions and power systems losses of South Sulawesi before and after using STATCOM and determine location of STATCOM installation. This research was carried out in South Sulawesi region specially at PT. PLN (Ltd.) Business Unit of SULSELTRABAR. To determined location of STATCOM installation, Trial and Error Method is used where buses which have voltage exist near to voltage interval limit allowed, became a reference of STATCOM installation. The results shows that voltage condition before STATCOM installed, exist to voltage interval limit allowed, that is, 0.95 – 1.05 pu. However, voltage of Tonasa Tonasa, Bontoala, Pangkep70, and Tallo Lama buses exist near to voltage interval limit allowed. Based on simulation results, an exact STATCOM installation is on two buses, that is, Tonasa and Bontoala buses until voltage of mentioned four buses are improved and near to fundamental voltage, respectively. Power losses after STATCOM installed is increase because when it installed, there are conduction losses and switching losses at STATCOM

Unlocking The Potential of Gallium Nitride (Gan) For Third-Generation Semiconductors: Advantages, Applications, And Future Prospects

Wide-bandgap materials, exemplified by gallium nitride (GaN), are poised to elevate electronic performance to new heights. This paper is focus on the third-generation semiconductor which is considered as the most promising semiconductor. The first section will discuss the fundamentals of CMOS and HEMT, including their construction, operation, benefits, and properties. The two are next be compared, and it is revealed that although GaN has some limitations on its cost and manufacture, it also having higher energy gap, compact size, higher efficiency, lower switching losses. Meeting the increasingly rigorous requirements associated with high power and high-density applications requires the use of these advantages. Then, using examples from the aerospace, mobile phone chargers, and LiDAR fields, applications of GaN HEMTs are discussed. The issues and prospects for third generation semiconductors are finally went over. It shows significant potential for energy efficiency benefits in infrastructure, and it is intriguing to see how the new semiconductor generation develops in the next few years.

Velocity-Controlled Piezoelectric Switching Energy Harvesting Device

The main purpose of this paper is to design the interface circuit of the piezoelectric energy harvesting device which can be suitable for a resistive load o a capacitive load. The vibrating velocity is detected to control the active rectifier to make the power factor correction of the piezoelectric layers. However, there are switching losses in the active rectifier in practice. The dead time and an inductor are thus taken into consideration to minimum the switching loss. The proposed circuit can increase 4 times than typical interface circuit of the piezoelectric layer, and can increase the charging speed of the capacitive storage buffer as well.

Active balancing circuit for advanced lithium-ion batteries used in photovoltaic application

An approach to the analysis and design of a bidirectional DC power converter for the cell voltage balancing control of a series connected lithium-ion battery string is presented in this paper. The proposed Cell Balancing Circuit (CBC) is designed to transfer the energy from the fully charged battery cell to the weakest one using a switch mode power converter operation. This operation maintains cell batteries at the same State-Of-Charge (SOC) and voltage range. Unlike previous battery balancing circuits, the balancing method uses only one magnetic component, resulting small size system. Simulation and experimental results show that the proposed cell balancing method can not only enhance the bidirectional battery equalization performance, but can also reduce the switching loss during the equalization period. Experiment results are provided to verify the operating principle of the proposed balancing method. Specific conditions of experiments are used to reproduce photovoltaic operations

Model Predictive Virtual Flux Control Method for Low Switching Loss Performance in Three-Phase AC/DC Pulse-width-Modulated Converters

Three-phase AC/DC pulse-width-modulated (PWM) converters have been widely employed in various renewable energy systems and industrial applications, which require a high-efficiency power converter operation. This article proposes a technique to reduce switching loss in AC/DC converters by integrating a voltage vector preselection strategy to model predictive virtual flux control. The voltage vector preselection strategy preselects available voltage vectors corresponding to switching states that lead to minimum switching loss in the phase leg, which conducts the highest current. By using preselected voltage vectors, clamping intervals are generated at every fundamental period to maintain the present switching states of the power switches, resulting in the reduction in switching loss. Additionally, by using virtual flux control, the proposed approach can effectively be used under both ideal and distorted source voltage conditions. The proposed method is compared with the conventional model predictive current control and the conventional model predictive virtual flux control. Both a simulation and experiment are performed to validate the correctness and effectiveness of the proposed method, which has been found to decrease the switching loss of an AC/DC converter by up to 15% compared to conventional control schemes at a negligible increase in the input current total harmonic distortion and DC output voltage ripple.

Arm‐current sensorless model predictive control for grid‐interfacing modular multilevel converter with reduced switching frequency

AbstractModel predictive control (MPC) emerges as an attractive alternative for the control of modular multilevel converters (MMCs) owing to its superior dynamic performance and ease of implementation. Nevertheless, conventional MPC's performance could be further improved by reducing dependence on weighting factors, switching frequency, and computational burden. To achieve these objectives, an arm‐current sensorless MPC is developed for a grid‐interfacing MMC in this article. The MPC is integrated with an arm‐current sensorless reduced switching frequency voltage balance algorithm that requires only switching vectors (where number of submodules per arm) to optimize the cost function. This method does not require knowledge of arm‐current direction to decide the charging and discharging state of the submodule capacitors. The developed control not only reduces the switching frequency of devices but also eliminates the need to sense the arm currents. As a result, it reduces the system's cost, complexity, computational burden, switching losses and provides a more reliable control method for MMCs with superior dynamic performance. Further, the effect of parameter mismatch on the developed MPC's dynamic performance and stability is studied. The developed MPC's effectiveness is validated through both simulation and experimental results and also compared with existing methods under different conditions.

Reduced stage three phase multisource hybrid converter for integration of PV and grid power

A three-phase-based Modified Dual Source Inverter has been proposed in this manuscript. The existing three-phase system is plagued with multistage power conversion, reducing its efficiency. The proposed converter can integrate two sources (AC and DC) simultaneously and supplies power to the three-phase load. It can switch its operation from the grid to grid-solar, solar to grid, as per the availability of the source. The inverter can operate as a three-phase DC to AC inverter, AC to AC inverter, and it can use grid and PV power directly with the help of a sino-squo-sino waveform. The system has been studied when switching from one mode to another. The system behavior has been analyzed on MATLAB SIMULINK and experimental setup. The proposed approach has been experimentally validated and operated using a TEXAS-based microcontroller (TMS320F28739d). The proposed method has reduced the THD to 4.32% when operated on solar and grid. The THD is 0.25% when operated on the grid power. The proposed system has also been compared based on components. It uses six IGBTs, One Mosfet and three Bidirectional switches.The reduced number of components reduces switching losses, which increases the system's efficacy and performance.

Simple Design Scheme for a 300 kW Modular NPC Inverter Using Thermal RC Network Analysis

This paper proposes a simple design scheme for a modular NPC inverter using thermal RC network analysis. The proposed design process is an efficient and straightforward approach to designing the heatsink for a 300 kW modular neutral-point-clamped inverter. The heatsink design plays a crucial role in achieving high power density of a power converter because the weight and size of the heatsink are primarily influenced by its type. The structure and dimensions of the heatsink are mainly determined based on the generated heat by losses of the power semiconductor switches. In this paper, a thermal RC network model was established using parameters from the power switch module and was applied to the simulation of the power converter. The thermal losses of the power semiconductor switches were calculated via this process, and the heatsink was designed according to the calculated thermal losses. The proposed design scheme was analyzed and compared with the thermal fluid dynamic model. To validate the feasibility of the proposed design process, The simulation results were compared with experimental results.

Novel Electric Propulsion System Analysis Method for Electric Vertical Takeoff and Landing Aircraft Conceptual Design

This paper proposes novel enhancements to the electric propulsion system analysis method for electric vertical takeoff and landing (eVTOL) aircraft conceptual design by considering the electrical characteristics of each electrical device in a more accurate manner. To this end, three modules for motor, inverter, and battery analysis are constructed using equivalent circuits and semi-empirical models. First, the motor analysis module is developed using equivalent circuit analysis with the operation control strategy for a permanent-magnet synchronous motor. Second, the inverter analysis module is built using average loss models for the switching and conduction losses. Third, the battery analysis module is improved using the near-linear discharge model to consider the voltage drop during operation. Moreover, additional modules, such as those for calculating the battery stack in series and parallel, as well as regression models for the motor and inverter performance parameters and consideration of the drive system type (direct or indirect, including a reduction gear), are implemented. A comparative study is presented from an analysis and design perspective while changing the drive system type (direct or indirect) and gear ratio, which highlights the importance of modeling electrical characteristics during eVTOL aircraft conceptual design.

A New Design and Embedded Implementation of a Low‐Cost Maximum Power Point Tracking Charge Controller for Stand‐Alone Photovoltaic Systems

This article presents a low‐cost maximum power point tracking (MPPT) charge controller designed to efficiently charge solar batteries using a simple and robust MPPT method, while providing protection against over‐currents and over‐voltages. The proposed MPPT approach utilizes a modified Incremental Conductance (INC) algorithm adapted to low‐cost embedded controllers, as it avoids all the mathematical division calculations typically used in the conventional INC algorithm. It also introduces a modified step size based only on photovoltaic (PV) power change to enhance tracking accuracy and convergence speed. Furthermore, to reduce the stress and switching losses of DC–DC converter, a feedback control with two proportional and integral (PI) compensators is also used to control both the PV voltage and to protect the battery from over‐currents using PV power limitation technique. Simulation results, carried out under MATLAB/Simulink, demonstrate the good performance of the proposed control scheme regarding any variations in atmospheric conditions, both for the MPPT control and for the battery charge control. Finally, a processor‐in‐the‐loop (PIL) test using a low‐cost Arduino MKR ZERO board is also performed to verify the hardware implementation of the proposed method. PIL results are in totally accordance with MATLAB/Simulink simulation results, which further proves the effectiveness of the proposed method.

Efficiency and PF Improving Techniques with a Digital Control for Totem-Pole Bridgeless CRM Boost PFC Converters

A totem-pole bridgeless boost converter is one of the most promising topologies for the power factor correction (PFC) stage in high-power applications due to its high efficiency and small number of components. However, due to the totem-pole structure of the field-effect transistor (FET), very high switching loss occurs via the reverse recovery current of the body diode. To solve these problems, critical mode (CRM) control is a good solution to achieve the valley switching technique. With valley switching of CRM control, the switching loss decreases drastically with decreasing turn-on voltage. But, although the CRM control enables valley switching, it is hard to make an exact valley switching control with general zero-voltage detection circuits. In addition, when a frequency limitation scheme is applied to prevent a very high frequency, the switch can operate with hard switching at the boundary of the frequency limitation. Furthermore, the CRM boost PFC has a low PF and high total harmonic distortion (THD) under light-load conditions due to the large negative current resulting from resonance between the inductor and parasitic capacitance. It becomes worse at near-zero input voltage since the resonance current becomes larger near zero-input voltage. Therefore, in this paper, a totem-pole bridgeless boost PFC converter with high efficiency, high PF, and low THD is developed using TMS320F28377 by Texas Instruments. Based on the basic digital structure of the totem-pole bridgeless converter, the proposed controls help with exact valley switching, PF and THD improvement, and frequency limitation. The prototype converter is verified using 90–264 VAC input voltages and 450 V/3.3 kW output specifications.

Voltage Equalization of Series Energy Storage Unit Based on LC Resonant Circuit

In energy storage systems, multiple energy storage monomers are usually connected in series to obtain higher voltages, but the inconsistency of the voltage of each energy storage monomer will reduce the utilization of the storage unit. To address this problem, this article proposes a method for equalizing the voltage of series energy storage units based on LC resonant circuit. The equalization circuit consists of a switch array and an LC resonant converter, which can achieve energy transfer between any monomer and continuous multi‐monomer, and realize zero‐current conduction of the switch. The equalization circuit does not have a large number of magnetic components, and for each additional energy storage monomer, the circuit only needs to add a pair of switches, which has the advantages of high flexibility and expandability. Finally, the equalization simulation experiments are conducted on the Matlab/Simulink platform for the energy storage unit composed of four series‐connected energy storage monomers. The experimental results show that under static equalization, the voltage reaches equalization in about 25 min and the equalization efficiency reaches 96.64%, which greatly reduces the switching loss, improves the equalization speed and efficiency, and verifies the feasibility and effectiveness of the method.

Hybrid MGWO- CSO optimized high gain Relift Luo converter for PV based grid tied PMBLDC drive system

Permanent Magnet Brushless Direct Current (PMBLDC) motor has become one of the most important motors in high performance drive systems, for industrial uses especially for electric vehicle (EV) applications to minimize their torque and current ripples. This work proposes a PV based high gain DC-DC converter for uninterruptible constant power supply to the PMBLDC drive application. PMBLDC drive with Hall Effect sensorsis used to make the variable speed operation due to its controllability. In this work, a Relift Luo converter is utilized because of its negligible ripple in output DC voltage, high voltage gain and reduced switching losses. To regulate this converter, PI controller is implemented and to tune the parameters of the controller, Hybrid Crow Search -Modified Grey Wolf Optimization (MGWO-CSO) techniqueis implemented. The surplus energy from PV is transferred to grid through Single phase Voltage Source Inverter (1 φVSI) after generatingadequate power to PMBLDC motor. When there is no power in Photovoltaic (PV)cell during night time, stored energy in grid gives supply to the PMBLDC motor. The motor is effectively controlled by the PI controller along with the hysteresis controller. Furthermore, the developed work is executed in MATLAB/Simulink to foreshow its effectiveness. As a consequence, the proposed work accomplished low THD value of 1.34, high efficiency of 98.2% with reduced switching lossescompared to the conventional techniques.