Design Of Power Electronic Converters Research Articles

Hybrid Data-Mechanism Modeling for Power Loss of a Boost Converter

Parameter design is the premise to ensure the optimal performance of power electronic converters, which depends on the accuracy of the established model. However, there is still many issues for improvements in modeling methods for the parameters design of power electronic converters. Due to the lack of key mechanism and the uncertainty of parameters, the existing modeling method shows poor accuracy or efficiency. In order to simplify the process and improve the accuracy of the existing modeling method, this paper proposes a hybrid data-mechanism modeling (HDMM) method for power loss of a typical power electronic converter, Boost converter, which is with UC3842 control chip. Based on the main loss from inductor, switch tube, diode and sampling resistance, the mechanism power loss modeling of Boost converter is built. Besides, the artificial neural network (ANN) is used to learn from the sampled data and train the data-driven model. To improve the accuracy of the mechanism model, the HDMM for power loss of Boost converter is established by modification of data-driven model with limited data. Through the proposed HDMM method, the mechanism modeling method and data-driven method are well combined and the HDMM has the advantage of high accuracy and strong generalization. In the end of this paper, feasibility and accuracy of the proposed HDMM method have been verified by hardware experiments.

Solar forecasting for a PV-battery powered DC system

The photovoltaic (PV) power generation sector has been growing rapidly as a result of the rising need for solar power and the advancement of PV technology. PV Power generation is affected by weather factors such as cloud cover, solar irradiation, temperature, breeze direction and speed, and the amount of rain or snow. As a result, a highly precise PV power predictor is essential to improve security and reliability in the face of financial penalties and ambiguity. Hence, this paper suggests a novel approach to improve the efficiency of PV-battery-powered DC systems by combining solar irradiance prediction using the Long Short-Term Memory (LSTM) algorithm with a power electronic converter design that incorporates a bidirectional port. The LSTM algorithm was employed to predict one week of solar data with a remarkable R2 score of 0.96. A steady-state analysis of the proposed Three-Port Converter (TPC) is performed for five different operating modes to guarantee optimal performance. The suggested system's prediction performance was tested using several error metrics such as Mean Absolute Error (MAE), Mean Square Error (MSE), and Root Mean Squared Error (RMSE), which were computed as 0.0318, 0.0027, and 0.0526, respectively. Results from the above error measures show that the suggested approach performs more effectively in estimating solar irradiance. The Adaptive Neural-Fuzzy Interface System (ANFIS) and Incremental Conductance (IC) algorithms are employed for Maximum Power Point Tracking (MPPT) and assessed against various atmospheric conditions. From the MATLAB simulation results, the tracking efficiency of the ANFIS-based MPPT technique is 99.97 %, which is superior to the IC-based MPPT technique. Furthermore, it proved that the suggested approach improves the efficiency of PV-battery-powered DC systems, which is more appropriate for real-world applications such as DC microgrids and Electric Vehicles.

Design Consideration of ZVS Single-Ended Parallel Resonant DC-DC Converter, Based on Application of Optimization Techniques

The paper presents the design of a single-ended transistor zero-voltage switch (ZVS) parallel resonant DC-DC converter. Due to the use of a resonant inverter in the structure of the DC-DC converter, it is characterized by high efficiency and improved performance. On the other hand, due to the specifics of the power circuit operation, in the work, it is proposed to find the values of some of the elements of the circuit of the electronic converter to be carried out based on the application of optimization. To solve this task, various tools available in Matlab/Simulink have been applied, as well as author’s programs specially developed for the purpose. The use of a hybrid method for the design of power electronic converters, which combines analytical and optimization approaches, is justified in cases where there is no adequate design procedure. With the increase in the complexity of the power topologies and their possible modes of operation, difficulties arise related to their design such as: assumptions and limitations in conducting the analysis and the corresponding methodologies based on this analysis; high order of the differential equations composing the mathematical models; need for highly qualified specialists in the field of design. The proposed approach does not negate the classical design methods based only on analytical ratios determined by analysis of power circuits, but complements and develops them with innovative ones based on the application of computational mathematics and information and communication technologies.

Advances in Modeling and Suppression Methods of EMI in Power Electronic Converters of Third-Generation Semiconductor Devices

With the development of high-frequency, miniaturized, and lightweight power electronic devices, third-generation semiconductor devices are more and more used in the main circuits of power electronic converters. The electromagnetic interference (EMI) generated by their fast switching can affect the performance of power electronic converters. Therefore, it is necessary to investigate the modeling and suppression methods of conducted noise in power electronic converters of third-generation semiconductor devices. This paper describes the EMI sources and coupling paths of EMI in third-generation semiconductor devices used in power electronic converters. The modeling methods of EMI are summarized from the perspectives of power devices and coupling paths. The suppression methods of conducted noise are summarized by suppressing EMI sources and improving coupling path characteristics. This paper provides a reference for the electromagnetic compatibility design of power electronic converters for third-generation semiconductor devices.

Research on Topology and Parameter Design of a Novel Flexible On-Load Voltage Regulator

Traditional on-load tap charger (OLTC) transformer use mechanical switch or anti-parallel thyristor as on-load tap changers. By changing the position of the tap chargers, the transformation ratio is changed, so as to achieve discrete step voltage regulation function. In this paper a novel Flexible On-Load Voltage Regulator (Flexible OLVR) is proposed, which is integrated design of Power Electronic Converter (PEC) and OLTC transformer. The converter is set at the primary side of the transformer, and it could control the output voltage accurately to relize the stepless voltage regulation when there is grid voltage fluctuation. The topology and operating principle of 10kV/0.4kV Flexible OLVR are given in this paper. Secondly, the main parameter design criteria is discussed through a group of design examples. Finally, the feasibility of the scheme is verified by the simulation waveform.

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Dynamic Avalanche Limit and Current Filamentation Onset Limit in 4H-Silicon Carbide High-Voltage Diodes

Dynamic avalanche (DA) phenomena and current filament (CF) formation are two extreme conditions observed in high-power devices, setting the maximum limit on turn-on/off current capability and di/dt in silicon (Si)-based bipolar devices. The properties of the silicon carbide (SiC) material enable devices with increased resilience for DA and CF compared with Si counterparts, and thus the safe-operating-area (SOA) limits may be extended. In this study, the limit of DA and CF in SiC-based semiconductor structures are investigated by numerical technology computer-aided design (TCAD) simulations, for different current levels, di/dt, and temperatures for high-voltage devices (e.g., 20-kV class). DA is first indicated for di/dt beyond 105 kA/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{s}$ </tex-math></inline-formula> for current densities in the range of 50–1000 A/cm2, at 448 K. Similarly, stray-inductance-induced avalanche conditions are initiated above 33 kA/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{s}$ </tex-math></inline-formula> , while CF is initiated for di/dt starting from 83 kA/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{s}$ </tex-math></inline-formula> for current densities in the range of 8.3 kA/cm2. Moreover, the effects of the stray inductance in the main circuit loop are studied which may cause critical voltage transients during certain operating conditions. The outcome of the study may be useful to determine SOA limits and to be used as input for power electronic converter design and gate driver design for high-power electronic systems.

Multiobjective Optimization Based Framework for Early Stage Design of Modular Multilevel Converter for All-Electric Ship Application

The Medium Voltage DC (MVDC) architecture for All Electric Ships (AES) has the potential to provide superior features compared to traditional 60-HZ AC distribution systems in terms of power density, power quality, and system stability. The MVDC system introduces extensive use of power electronics equipment into the shipboard power system (SPS) design that brings complexity to the system design. These power electronics equipment connect the power sources and load centers to the MVDC bus and play a major role in handling system faults. This paper focuses on developing a framework to determine the volume and failure rate of a Modular Multilevel Converter (MMC) for early stage ship design. Two different methodologies (Taguchi method and a genetic algorithm) were used to determine the best design from a robust set of design options. Once the design parameters have been identified, the Taguchi method forms orthogonal array to explore and evaluate designs. At the end of the design cycle, it identifies the best parameters from a large set of design parameters to achieve lower volume and failure rate. These parameters are used as input to the optimization process. This helps to narrow out the number of inputs for optimization algorithm. The Nondominated Sorting Genetic Algorithm II (NSGA-II) has been integrated with converter design tool to minimize the volume and failure rate of MMC. The results show that the optimization algorithm coupled with Taguchi Method provides the lowest volume and failure rate for MMC. One of the goals of early-stage ship design is to develop preliminary design and evaluation of trade space to narrow it down. This paper is expected to aid early-stage ship design of power electronics converter design for MVDC systems in SPS.

Design Methodology of Free-Positioning Nonoverlapping Wireless Charging for Consumer Electronics Based on Antiparallel Windings

Free positioning wireless charging for consumer electronics allows the devices to be charged at arbitrary positions and angles to improve user experience. However, a user-initiated sudden movement of the device during charging can cause hazards due to the abrupt variation of the coupling coefficient. To solve this issue, the coupling coefficient variation at different positions should be mitigated, which is also good for the design and high-efficiency operation of power electronics converters. This article proposes a design methodology to employ antiparallel windings to smooth the coupling coefficient variation over different positions by reducing the coupling coefficient at central positions and enhancing it at boundary positions. Two optimization methods are proposed: turn-by-turn optimization and winding-by-winding optimization. A design flow is offered. The hexagonal coil is compared with the square coil and proved to achieve better performance than the latter. An experimental prototype is implemented to validate the effectiveness of the proposed design methodology.

Magnetic Coupling Common Mode Conducted EMI Analysis and Improvement in a Boost Converter

Common mode (CM) electromagnetic interference (EMI) has been a difficult subject in electromagnetic compatibility (EMC) analysis and design of power converters for electric vehicles (EV) because of its complex formation mechanism and hidden propagation path. This paper studies a new mechanism of CM conducted emission caused by the leakage flux of a toroidal inductor in the main circuit of a boost DC/DC converter. The stray magnetic source and the CM inducted loops are firstly identified out by simulation analysis and experiments. Then a comprehensive conducted emission circuit model including magnetic coupling parameters is built to explain this CM EMI formation mechanism. Finally, several effective magnetic coupling suppression methods are proposed and verified, such as changing the installation angle of the inductor and the shape of the magnetic core. The research results are helpful to the EMC understanding and design of power electronic converters.

Stability Analysis and Performance Evaluation of a Multifunction Converter

This paper proposes a converter circuit topology that can perform two functions rather than only one function, normally used in the traditional design of Power electronic converters (PEC). Initially the operation of the proposed circuit in boost DC-DC positive or negative mode and inverting mode are outlined. This is followed by the development of a state-space model and extensive frequency-domain and pole-zero stability analyses for the boost mode that give information about the circuit elements requirements and controller design for it . The proposed converter is simulated using Matlab environment and its performance is evaluated using two control strategies to control the load voltage. The results show the good performance of the converter over a wide range of output voltages and converter capability to reverse the output signal performance and follow the reference values via a logic-based control scheme, which is one of the smart grid and micro grid application requirements.

Incorporating Power Electronic Converters Reliability Into Modern Power System Reliability Analysis

This article aims to incorporate the reliability model of power electronic converters into power system reliability analysis. The converter reliability has widely been explored in device- and converter-levels according to physics of failure analysis. However, optimal decision-making for design, planning, operation, and maintenance of power electronic converters require system-level reliability modeling of power electronic-based power systems. Therefore, this article proposes a procedure to evaluate the reliability of power electronic-based power systems from the device-level up to the system-level. Furthermore, the impact of converter failure rates including random chance and wear-out failures on power system performance in different applications such as wind turbine and electronic transmission lines is illustrated. Moreover, because of a high calculation burden raised by the physics of failure analysis for large-scale power electronic systems, this article explores the required accuracy for reliability modeling of converters in different applications. Numerical case studies are provided employing modified versions of the Roy Billinton Test System (RBTS). The analysis shows that the converter failures may affect the overall system performance depending on its application. Therefore, an accurate converter reliability model is, in some cases, required for reliability assessment and management in modern power systems.

Design of a one kilowatt wireless charging system for electric vehicle in line with Bharath EV standards

Abstract Emerging technologies in an electric vehicle (EV) had greater advancement in the control, batteries and electric motors design. But safety and reliability are the major concerns when the consumer is dealing with a high voltage conductor for charging. The recurring of plugging in the switch for charging is an undeniable disadvantage. Therefore, to eliminate the human intervention in charging of a battery, wireless power transfer (WPT) will be the most effective methodology to charge the EV. This paper aims at building the prototype of 1 kW inductive WPT with high frequency supply with power converters. To design this system, standards of EV charging systems are incorporated; also, a suitable coil structure is identified for the given EV model as per the standards. The mismatch or misalignment of the receiver coil, air gap between receiver–transmitter (i.e., proximity) and compensation techniques are considered in this work. Efficient design of power electronic converter is implemented for both transmitter and receiver side. Both coil design model and the power electronic system are integrated to test the performance of proposed WPT technology.

Multi-objective Design and Optimization of Power Electronics Converters With Uncertainty Quantification—Part II: Model-Form Uncertainty

The second part of the multi-objective design and optimization with parametric and model-form uncertainty quantification (MDO with P&MF-UQ) is dedicated to incorporating MF-UQ into the MDO framework. MF-UQ is used to estimate the error due to modeling inaccuracies and to validate the mathematical models used in the MDO framework. In this approach, the sensitivity index introduced in the first part of the article is modified too so that it is a quantitative measure of system design robustness with regards to modeling inaccuracies as well as the manufacturing variability in the design of systems with multiple performance functions. The optimum design solution is finally realized by exploring the Pareto Front of the enhanced performance space, where the model-form error associated with each design is used to modify the estimated performance measures and the parametric sensitivity of each design point is considered to discern between cases and help identify the most parametrically robust of the Pareto-optimal design solutions. To demonstrate the benefits of incorporating uncertainty quantification analysis into the design optimization from a more practical standpoint, design of a robust high-efficiency high-power-density 1.25 kW Vienna-type rectifier is used as a case study to compare the theoretical analysis with a comprehensive experimental validation. It is shown that the final design selected using the MDO with P&MF-UQ reduces the design sensitivity and system loss by 33% and 5%, respectively, compared to the optimal design selected using the conventional MDO.

Control Design and Stability Analysis of Power Converters: The Discrete Generalized Bode Criterion

For the controller design and stability analysis of power electronic converters, the Bode stability criterion and its subsequent revisions are the most practical tools. However, even though the control of the power converter is usually implemented in a microprocessor, none of these methods is infallible when applied to a discrete system. This article therefore proposes a new stability criterion, named the Discrete Generalized Bode Criterion (DGBC). This method is based on the Nyquist criterion but developed from the open-loop Bode diagram, evaluated also at 0 Hz and at the Nyquist frequency. The proposed criterion combines the advantages of the Nyquist and Bode criteria, since it is always applicable and provides an interesting and useful tool for the controller design process. The method is applied to design an active damping control of an inverter with LCL filter, showing how the proposed criterion accurately predicts stability, in contrast to the existing Bode criteria. The theoretical analysis is validated through experimental results performed with a three-phase inverter and an LCL filter.

Analysis of the Usefulness Range of the Averaged Electrothermal Model of a Diode–Transistor Switch to Compute the Characteristics of the Boost Converter

In the design of modern power electronics converters, especially DC-DC converters, circuit-level computer simulations play an important role. This article analyses the accuracy of computations of the boost converter characteristics in the steady state using an electrothermal averaged model of a diode–transistor switch containing an Insulated Gate Bipolar Transistor (IGBT) and a rapid switching diode. This model has a form of a subcircuit for SPICE (Simulation Program with Integrated Circuit Emphasis). The influence of such factors as the switching frequency of the transistor, the duty cycle of the signal controlling the transistor, the input voltage, and the output current of the boost converter on the accuracy of computing the converter output voltage and junction temperature of the IGBT and the diode were analysed. The correctness of the computation results was verified experimentally. Based on the performed computations and measurements, the usefulness range of the model under consideration was determined, and a method of solving selected problems limiting the accuracy of computations of the characteristics of this converter was proposed.

Novel Highly Efficient/Compact Automotive PCB Winding Inductors Based on the Compensating Air-Gap Fringing Field Concept

The design of power electronic converters is subject to extreme cost pressure, especially in the automotive sector. Consequently, each component needs to be optimized regarding material and manufacturing cost. The latter is especially important for magnetic components, as the expensive wire-wrapping process has a significant impact on the overall production costs. In this article, a new inductor concept is proposed, where the winding is directly integrated into the printed circuit board (PCB), while at the same time the usually large high-frequency conduction losses are mitigated. This is achieved by using the fringing field around a single air gap or several (distributed) air gaps for compensating the adverse magnetic skin and proximity fields within the winding. Consequently, low ac to dc resistance ratios are achieved and the required copper cross-section of the winding can effectively be reduced. Furthermore, a thermal model for the printed circuit board winding is derived, which allows for designing PCB windings close to the thermal limit, and therefore inductors with very high power densities are obtained. Finally, the findings of this article are verified by experimental measurements and a simplified design sequence is described.

Multi-objective Design and Optimization of Power Electronics Converters With Uncertainty Quantification—Part I: Parametric Uncertainty

This article presents a robust multi-objective design and optimization approach with parametric and model-form uncertainty quantification (MDO with P&MF-UQ). The first part of the article focuses on incorporating parametric uncertainty quantification (P-UQ) into the MDO framework, where a sensitivity index is defined as a quantitative measure of system design robustness with regards to manufacturing variability in the design of systems with multiple performance functions. To demonstrate the benefits of incorporating P-UQ analysis into the design optimization framework, this article presents the design and optimization of a robust high-efficiency high-power-density 1.25 kW Vienna-type rectifier. The optimum design solution is realized by exploring the Pareto Front of the enhanced performance space where the parametric sensitivity of each design point is considered to discern between cases and help identify the most parametrically-robust of the Pareto-optimal design solutions. It is shown that the design sensitivity is reduced by 39% when the optimum design is selected using MDO with P-UQ rather than the conventional MDO.

Analytical model of a resonator for PCB-embedded power conversion

This study proposes a comprehensive analytical model of the magnetism, electrostatics, and loss mechanisms of a simple and economical structure with a printed circuit board-embedded magnetic component (coil, high leakage transformer, or resonator) for electric power conversion in the range 1 W–100 W. The predictions of this model are compared to finite element simulations. A good match is obtained over a wide bandwidth (up to at least 10 MHz). The model is adapted to predict the electrical characteristics of the device used as a monolithic series-LC tank, with a resonant frequency in the MHz range. A prototype is built to prove the applicability of the model, which is intended for the design and optimisation of power electronics converters.

Fault-Tolerant SRM Drive with a Diagnosis Method Based on the Entropy Feature Approach

The power electronic converter design is essential for the operation of the switched reluctance motor (SRM). Thus, a fault-tolerant power converter is fundamental to ensure high reliability and extend the drive operation. To achieve fault tolerance, fault detection and diagnosis methods are critical in order to identify, as soon as possible, the failure mode of the drive. To provide such capability, it is proposed in this paper a new fault-tolerant power converter scheme combined with a fault detection method regarding the most common power semiconductors failures in SRM drives. The fast and reliable proposed diagnosis method is based on the entropy theory. Based on this theory, normalized indexes (diagnostic variables) are created, which are independent from the load and speed of the motor. Through this method, it is possible to identify the faulty leg, as well as the type of power semiconductor fault. To test and evaluate the proposed solution several laboratory experiments were carried out using a 2 kW four-phase 8 / 6 SRM.