Power Electronic Converter Topologies Research Articles

A Deep Reinforcement Learning Approach to DC-DC Power Electronic Converter Control with Practical Considerations

In recent years, there has been a growing interest in using model-free deep reinforcement learning (DRL)-based controllers as an alternative approach to improve the dynamic behavior, efficiency, and other aspects of DC–DC power electronic converters, which are traditionally controlled based on small signal models. These conventional controllers often fail to self-adapt to various uncertainties and disturbances. This paper presents a design methodology using proximal policy optimization (PPO), a widely recognized and efficient DRL algorithm, to make near-optimal decisions for real buck converters operating in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM) while handling resistive and inductive loads. Challenges associated with delays in real-time systems are identified. Key innovations include a chattering-reduction reward function, engineering of input features, and optimization of neural network architecture, which improve voltage regulation, ensure smoother operation, and optimize the computational cost of the neural network. The experimental and simulation results demonstrate the robustness and efficiency of the controller in real scenarios. The findings are believed to make significant contributions to the application of DRL controllers in real-time scenarios, providing guidelines and a starting point for designing controllers using the same method in this or other power electronic converter topologies.

Technical Review and Survey of Future Trends of Power Converters for Fast-Charging Stations of Electric Vehicles

The development and implementation of electric vehicles have significantly increased and are profoundly reshaping the automotive sector. However, long charging times, limited driving range, and difficulties as to suitable charger converter design are the main limitations of the adoption of EV technology. DC fast-chargers offer the best solution for mitigating the charging time problems of EVs. This paper provides an extensive review of the status of the technical development of fast-charging infrastructure architectures and standards, and a classification of fast-charging methods. Key power electronic converter topologies for fast-charging systems, with their advantages and comparisons, are also addressed.

Design and Development of High Frequency Inverter for Wireless Power Transfer Application

A number of power electronics converter topologies are implemented as Wireless Power Transfer (WPT) systems applications expand. In these applications, the optimal converter design is essential for handling the high power and frequency operation. In this paper, Simulation & Hardware development of High frequency Inverter with 90KHz frequency with Pulse Width Modulation switching strategy is presented. The inverter topology is simulated in 2021a version MATLAB/Simulink with R and RL loads and its conversion ability is proven through relevant waveforms. Simultaneously designed and developed prototype model of power rating 100watt with Mosfet as switches at output voltage of 230V with R load and analyse the output behaviour of voltage waveforms at various loads. The outcomes show effective enhancements for the proposed design.

Different Topologies of Electrical Machines, Storage Systems, and Power Electronic Converters and Their Control for Battery Electric Vehicles—A Technical Review

Electric vehicles (EVs) are emerging as an alternative transportation system owing to a reduction in depleting lubricates usage and greenhouse gas emissions. This paper presents a technical review of each and every sub-system and its feasible control of battery EV (BEV) propulsion units. The study includes the possible combination of electrical machines (EMs), storage system, and power electronic converters and their associated control strategies. The primary unit, i.e., EM, is the heart of the EV, which is used to drive the vehicle at the desired speed as well as to restore the regenerative braking (RB) energy that is generated to enhance the overall system reliability. To electrify the transportation sector, it is necessary to include new options of power electronic converter topologies and their associated control strategies for numerous reasons, which include extracting maximum power from sources in case the EV is powered from renewable energy resources, boosting the energy storage capability for longer electric range, managing power flow from the source to battery or battery to vehicle or vehicle to battery, and regulating the speed of the vehicle and braking control. Based on the survey, the suitable combination of sub-systems and their control for three and four-wheeler EVs are summarized in this paper.

A design optimisation tool to minimise volume and failure rate of the modular multilevel converter and the thyristor-controlled rectifier

The unfolding of MVDC (Medium Voltage DC) systems has the prospects to enable the incorporation of power electronic converters with higher power density and reliability. A tool with an integrated design approach is required to minimise the overall system volume by identifying optimal components. In this paper, a component-level early-stage design tool has been developed to attain the minimum achievable volume and failure rate for MVDC power converters. The developed tool optimises the choice of semiconductor switching devices, required heatsink, and other passive components (including dc-link filters and inductors) to minimise failure rate and overall converter volume. The optimisation algorithm employs the non-dominated sorting genetic algorithm (NSGA-II) to evaluate designs based on developed fitness functions. The design tool demonstrates the trade-off when evaluating multiple converter topologies and helps make an informed decision. A comparative study between two converter topologies shows the outcomes in terms of targeted metrics (volume and failure rate). This tool is expected to benefit early-stage design to perform trade-off studies among power electronic converter topologies based on key metrics like volume and failure rate.

Lithium‐ionbattery and supercapacitor‐based hybrid energy storage system for electric vehicle applications: A review

Hybrid energy storage system (HESS) has emerged as the solution to achieve the desired performance of an electric vehicle (EV) by combining the appropriate features of different technologies. In recent years, lithium-ion battery (LIB) and a supercapacitor (SC)-based HESS (LIB-SC HESS) is gaining popularity owing to its prominent features. However, the implementation of optimal-sized HESS for EV applications is a challenging task due to the complex behavior of LIB and SC under different driving behaviors. Besides, the power electronics (PE) converter configurations and system-level optimizations, include component sizing (CS) and power-energy management strategy (PEMS), are essential for developing efficient HESS. Therefore, this paper reviews existing LIB-SC HESS, different possible combinations of CS and PEMS, generalized algorithm formulation, and algorithms used for both CS and PEMS. The current issues of LIB-SC HESS regarding the performance in EV applications, PE converters, and optimization algorithms are also analyzed. In addition, future recommendations for the development of efficient LIB-SC HESS are provided to inspire researchers for further studies. Highlights Lithium-ion battery (LIB) and supercapacitor (SC)-based hybrid energy storage system (LIB-SC HESS) suitable for EV applications is analyzed comprehensively. LIB-SC HESS configurations and suitable power electronics converter topologies with their comparison are provided. System-level optimization of LIB-SC HESS and generalized steps involved in implementing the optimization algorithm for component sizing (CS) and power-energy management strategy (PEMS) are discussed. A rigorous study on CS and PEMS is presented to develop efficient LIB-SC HESS. Current challenges and future recommendations for the development of LIB-SC HESS for EV applications are provided.

Recent Advances of Wind-Solar Hybrid Renewable Energy Systems for Power Generation: A Review

A hybrid renewable energy source (HRES) consists of two or more renewable energy sources, suchas wind turbines and photovoltaic systems, utilized together to provide increased system efficiency and improved stability in energy supply to a certain degree. The objective of this study is to present a comprehensive review of wind-solar HRES from the perspectives of power architectures, mathematical modeling, power electronic converter topologies, and design optimization algorithms. Since the uncertainty of HRES can be reduced further by including an energy storage system, this paper presents several hybrid energy storage system coupling technologies, highlighting their major advantages and disadvantages. Various HRES power converters and control strategies from the state-of-the-art have been discussed. Different types of energy source combinations, modeling, power converter architectures, sizing, and optimization techniques used in the existing HRES are reviewed in this work, which intends to serve as a comprehensive reference for researchers, engineers, and policymakers in this field. This article also discusses the technical challenges associated with HRES as well as the scope of future advances and research on HRES.

Power electronic converter topologies for switched reluctance motor towards torque ripple analysis

The power converter circuit plays a vital role in electric drives. The converters performance has a significant impact on the drive performance as well as cost. There are different motors applied in electric drives, this study primarily focused on torque ripple analysis of Switched Reluctance Motor (SRM) drive and its converter topologies. The SRM salient poles have the stator outer side and the rotor inner side, which is different from the other polyphase machines. Although there have been a number of converters for SRM drives through the years, each converter has its own set of benefits and drawbacks. The choice of a converter is dictated by the application, this article includes a comparative analysis of SRM converter topologies, two level converters branches and multi-level converters branches were discussed in detail with schematic diagram. Based on the survey it is found that an asymmetrical bridge converter best suits for Electric vehicle application due to its advantage of reducing fault tolerant, fast demagnetization and regenerative braking capability. This paper presents the study of 10 kW SRM Drive controlled by asymmetrical bridge converter, in three different phase modification mode such as 6/4, 8/6 and 10/8 using MATLAB simulation and the torque ripples are analysed for each case.

Reliability and Cost-Oriented Analysis, Comparison and Selection of Multi-Level MVdc Converters

DC technology has gained considerable interest in the medium voltage applications due to the benefits over the AC counterpart. However, to utilize the full capacity of this development, the selection of a suitable power electronic converter topology is a key aspect. From the pool of voltage source converters (VSC's), it is unclear which topology is suitable for multi-megawatt applications at medium voltage dc (MVdc) levels. To address this, the paper proposes a selection guideline based on reliability and optimum redundancy levels of VSCs for MVdc applications. This will be combined with other functional factors such as operational efficiency and return-on-investment. Three candidate multi-level topologies namely three-level neutral point clamped converter (3L-NPC), modular multi-level converter (MMC) and cascaded 3L-NPC (which is being used for the first MVdc link in the U.K.) have been evaluated over two-level-VSC from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 10 kV to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 50 kV. Results show that with the increase of MVdc voltage level MMC shows better performance whereas at low MVdc voltage levels 3L-NPC is the prominent topology.

Analysis and Control of Current-Fed Integrated Dual-DC Boost Converter Topology

This article introduces a dual-input single-output dc–dc power electronic converter topology to interface two independent sources into a common output. The proposed converter is denoted as integrated dual-dc boost converter (IDDBC), and this topology provides step-up conversions for both inputs using three controllable switches. Due to its architecture, IDDBC can be adapted to provide uninterrupted power (realizing a dispatchable system) even if any one of the two input sources are unavailable or has significant output power variation. The steady-state analysis, modeling, and design of the converter are presented, and a pulsewidth-modulation control scheme is proposed. The closed-loop control system for the converter consists of voltage-mode control for output and current-mode control for one-source input current. The behavior of converter operation is validated through experimentation on a digital-signal-processor-based laboratory prototype.

Controller-Embeddable Probabilistic Real-Time Digital Twins for Power Electronic Converter Diagnostics

In this article, an approach is proposed for the online diagnostic analysis of power electronic converters utilizing real-time, probabilistic digital twinning. Under this approach, a digital twin (DT) of a power converter is defined as a real-time, probabilistic simulation model with stochastic (random) variables, developed using generalized polynomial chaos expansion. The DT models are partitioned in perspective of control layers for power converter subsystems in the approach, with emphasis on the application and converter control layers. Real-time executed solvers of these divided probabilistic DT models are embedded into power converter controllers running on field programmable gate array (FPGA) computing devices. Using a monitoring system, the real-time probabilistic DTs at each control layer and the corresponding physical twins of the power converter are compared by the controllers to determine if the power converter is operating within probable behavior. Knowing the large computational cost of probabilistic modeling, the resource usage and timing of real-time DT solvers on modern FPGAs is reported for common power electronic converter topologies, showing the approach is feasible and able to perform probabilistic real-time simulation of smaller power converters in perspective of application and converter control layers using $\leq 2\; \mu s$ time steps, with as low as $\text{70}\;{\rm ns}$ steps; while staying embeddable within FPGA-based controllers. To highlight the capabilities of the proposed approach, a case study is presented using a probabilistic DT in the application layer controller of a pair of converters to comparatively monitor their behavior and corresponding controller action under hardware-in-the-loop testing.

Extreme Fast Charging of Electric Vehicles: A Technology Overview

With the number of electric vehicles (EVs) on the rise, there is a need for an adequate charging infrastructure to serve these vehicles. The emerging extreme fast-charging (XFC) technology has the potential to provide a refueling experience similar to that of gasoline vehicles. In this article, we review the state-of-the-art EV charging infrastructure and focus on the XFC technology, which will be necessary to support the current and future EV refueling needs. We present the design considerations of the XFC stations and review the typical power electronics converter topologies suitable to deliver XFC. We consider the benefits of using the solid-state transformers (SSTs) in the XFC stations to replace the conventional line-frequency transformers and further provide a comprehensive review of the medium-voltage SST designs for the XFC application.

Power Electronic Converter Configurations Integration with Hybrid Energy Sources – A Comprehensive Review for State-of the-Art in Research

The electricity demand is increasing day by day. On the other side, fossil fuels are depleting at a higher rate. The abundantly available renewable energy sources like solar, wind, and fuel cells are becoming popular sources of energy. But due to the intermittent availability of these renewable energy sources, two or more energy sources are integrated together. Power electronic converters are used for integrating different energy sources. Various power electronic converter (PEC) topologies have been proposed and analyzed in detail to control maximum power point, voltage, frequency, and harmonic distortions. Each of these configurations will differ in its topology and operating principle. The objective of this paper is to present a comprehensive review of various aspects of PEC configurations available for integration of renewable energy sources by systematization into three groups (AC shunt coupled, DC shunt coupled, and hybrid coupled systems). Emphasis is also given to coordination power control, maximum power point, and grid integration challenges related to the hybrid energy system. Furthermore, a general, system modeling of solar, wind, and grid integration is presented here to give an overall picture of a hybrid renewable energy system.

Technological Advancement in PMSG Based Wind Energy Conversion Systems: Issues and Challenges

Background: Since its beginning in 1980, wind energy generation has gained newer heights and emerged as the most promising renewable energy technology at present. Wind turbine rating has increased from few kW to MW and now multi-MW turbines are also available and in operation too. Introduction: Impact of wind turbines on the grid has significantly increased with increased penetration of wind power into the grid. In order to improve the performance characteristics of the wind turbines, and make them suitable for grid integration, more advanced generators, control schemes, and power converters are required. Latest wind energy market trends and research articles reflect the popularity and market capture of Permanent Magnet Synchronous Generator (PMSG) for wind turbine applications. Method: The present work is dedicated to important electrical aspects concerning PMSG based wind energy conversion system. Starting with the technological development of wind turbine, state-of-the-art PMS based wind turbine concepts with power electronic converter topologies are discussed. Result: A comprehensive analysis of converter topology, grid integration, integration issues, and future research and technology trends are presented.In addition steady state performance analysis of PMSG based wind turbine is presented depicting issues with different control schemes. Conclusion: The study presented in this paper envisages help to the researcher in this area by providing them clear insight of various power electronic interfaces, their control complexities and various issues of concern. In addition we are assure that steady state analysis presented in this paper will attract the newcomers in this field of research.

Solid-State Transformers for Distribution Systems–Part I: Technology and Construction

Solid-state transformers (SSTs) are an emerging technology that has been developed to improve the stability, reliability, and economic operation of distribution systems. These new transformers are composed of a medium ac voltage (MV) stage, a dc stage, and a low ac voltage (LV) stage. Passive and active dc links are used to construct the dc stage in SSTs in order to offer new functionalities, including hybrid (ac and dc) distribution, reactive power compensation, voltage/frequency regulation, power quality improvement, and distributed generation utilization. On one hand, a distribution SST has its ac stage connected to an MV level, which mandates specific power electronic converter (PEC) topologies, switching element capabilities, and filtering circuits. On the other hand, the dc-link stage has to provide isolation between the MV and LV levels, which requires the employment of isolated dc PECs. Part I of this work provides a review of SST designs and constructions (for deployment in distribution systems), in terms of the required technology, supported functionalities, and construction features.

Review of AC-DC power electronic converter topologies for power factor correction

&lt;p&gt;Increased harmonic content and low power factor in power systems caused by power converters have been of great concern. To overcome this, several converter topologies employing advanced semiconductor devices and control schemes have been proposed. The aim of this paper is to identify a low cost, small size, efficient and reliable ac to dc converter to meet the input performance index of uninterrupted power supply. In this paper, comparison between three converters namely AC-DC Cuk rectifier, Fly back converter &amp;amp; Interleaved SEPIC converter have been carried out. For the above converters both bridged and bridgeless topologies have been analysed. The working of all the three types of converter has been illustrated with relevant waveforms followed by the simulation results. Comparison of the three converters have been done based on the parameters namely Displacement Factor, Supply Power Factor&amp;amp; supply THD. The results are verified.&lt;/p&gt;

Power‐take‐off topology comparison for a wave energy converter

Wave Energy Converters (WECs) generally use a Mechanical Power-Take-Off (MPTO) involving hydraulics or gearing to optimise the extraction of energy from the incoming waves before converting it into electrical energy via a high speed rotating generator. This simplifies the design of the Electrical Power Conversion System (EPCS). Further, it facilitates the use of mechanical energy storage such as hydraulic accumulators to reduce the peaky nature of the power flow and allows the WEC resonant frequency to be tuned for maximum energy capture. This work compares two power electronic converter topologies for an Electrical PTO (EPTO). This EPTO is intended to replace the aforementioned MPTO and generator with a Permanent Magnet Linear Machine (PMLM) directly coupled to the WEC. The compared topologies comprise either a Current Source Converter (CSC) or a Voltage Source Converter (VSC) as the generator interface working in combination with a DC-DC converter and an Energy Storage System (ESS). The principle differences between the two topologies are explored and losses are evaluated in a modular EPCS working with a WEC. Wide-bandgap power electronic switches are assumed for both topologies over a range of switching frequencies. The evaluation concludes that the CSC topology is advantageous at higher switching frequencies.

Advanced Electric Vehicle Fast-Charging Technologies

Negative impacts from the dominant use of petroleum-based transportation have propelled the globe towards electrified transportation. With this thrust, many technological challenges are being encountered and addressed, one of which is the development and availability of fast-charging technologies. To compete with petroleum-based transportation, electric vehicle (EV) battery charging times need to decrease to the 5–10 min range. This paper provides a review of EV fast-charging technologies and the impacts on the battery systems, including heat management and associated limitations. In addition, the paper presents promising new approaches and opportunities for power electronic converter topologies and systems level research to advance the state-of-the-art in fast-charging.

A Fast and Stable Method for Modeling Generalized Nonlinearities in Power Electronic Circuit Simulation and Its Real-Time Implementation

Nonlinearities have been the major obstructions that limit the computational efficiency in power electronic circuit simulation for a long time. Yet there is no standard way for dealing with them. This paper presents a new method that makes the handling of nonlinearities fast and stable. In the proposed method, nonlinearities are transformed into a uniform representation—a constant resistor in parallel with a companion current source, thus making the system admittance matrix constant for fixed time-step simulation. To solve for the corresponding companion current source, nonlinearities are treated as either current or voltage sources and a diagonal time-varying matrix equation is developed. Three methods are proposed for solving the matrix equation—precomputed inversion or factorization, modified Gaussian elimination, and updating inverse using the Sherman–Morrison formula—that can fit different system sizes and applications. The proposed method is validated by two common power electronic converter topologies, both in offline and real-time simulation. Offline tests show that the proposed method achieved the same accuracy with the mature simulation software while being more than ten times faster. The same test cases are also implemented into field programmable gate arrays based real-time simulation experiments for verification.

Thermal stress reduction of quasi-Z source inverter drive by model predictive control

The quasi-Z source inverter (qZSI) is one of the most promising power electronics converter topologies suitable for traction applications. The thermal stress in power modules is one of the most important causes of their failure, which is not considered during the control of qZSI drive. Thus, this paper proposes a thermal stress reduction scheme for qZSI drive, which utilizes finite control set model predictive control. The cost function is designed by including terms of switching counts, number of cycles to failure and inverter constraints in addition to the currents and capacitor voltage. This allows one to achieve the minimum thermal stress for the best possible overall performance of qZSI drive. The approach is proved using simulation and experimental results.