Advanced control methods for power electronics systems

The literature review explores the evolution and advancements in the implementation of latency-based solvers for real-time simulation of power electronic systems using field-programmable gate arrays (FPGAs).The journey begins with Dr. Johnson, who highlights the exceptional capability of FPGAs to outperform traditional general-purpose processors in floating-point throughput for power flow computations.[1] This foundational work sets the stage for subsequent research that delves deeper into the acceleration of various computational tasks using FPGA technology.As the field continues to mature, new methodologies and algorithms are developed to harness the full potential of FPGAs.These innovations aim to not only improve the performance of power electronic simulations, but also to enhance the flexibility and reconfigurability of the systems.Researchers are exploring novel approaches such as adaptive solvers, where the latency of the system dynamically adjusts based on the complexity of the simulation.[2] This adaptive nature allows for efficient resource allocation and utilization in real-time applications, leading to improved overall system performance.Furthermore, advancements in FPGA architecture and design techniques enable the integration of multiple solvers on a single chip, catering to the increasing demand for multi-domain simulations.This integration paves the way for seamless co-simulation of diverse power electronic systems, including converters, inverters, and motor drives.Additionally, the emergence of high-level synthesis tools simplifies the development process, making it more accessible to researchers and practitioners alike.[3] These tools enable the conversion of high-level hardware description languages into FPGA-specific designs, alleviating the need for manual low-level coding.Moreover, the availability of FPGA development boards and development kits provides a testing ground for prototype implementations, allowing researchers to evaluate their designs in a real-world scenario.[1] In conclusion, the literature review highlights the evolutionary journey of latency-based solvers for real-time power electronic simulations using FPGAs.From the initial groundbreaking work to the current state-of-the-art advancements, researchers have continuously pushed the boundaries to achieve higher performance and accuracy.With ongoing research and innovation, the field is poised for further growth and development, promising even more efficient and versatile solutions for real-time power electronic simulations.[4] [5] build on this foundation by addressing the parallelization of the sparse Matrix-Solve phase in SPICE applications.Their findings indicate that reduced-precision floating-point datapaths can significantly enhance performance, achieving speedups of 2-18 times over single-core microprocessor implementations.This article emphasizes the importance of exploiting parallelism and optimizing resource usage in FPGA designs.The authors present an FPGA-based framework that effectively tackles and addresses the inherent challenges associated with simulating intricate physical phenomena utilizing unstructured spatial discretization.This innovative and pioneering approach significantly enhances data locality and memory access patterns, thereby showcasing a remarkable and astonishing 90 times speedup as compared to high-performance microprocessors.[1] The demonstrated outcomes and results of this work serve to underscore and emphasize the critical significance of efficient and effective memory management when harnessing and leveraging the immense computational power offered by FPGAs.This research proves to be a groundbreaking and pivotal advancement in the field, with far-reaching implications and potential for further exploration and application in diverse areas of study.[6] Introduce FPGA-SPICE, which is a state-of-the-art simulation-based power estimation framework that perfectly integrates seamlessly with cutting-edge architecture exploration tools.

This paper describes a new algorithm for simulation of power electronic systems. Piecewise-linear (PWL) approximation is used to model nonlinear components, including switching devices, nonlinear reactive components, and nonlinear control circuitry. A representation of PWL elements is constructed such that a constant system matrix is obtained, regardless of the states of PWL elements. An efficient method for state determination is proposed, which is capable of resolving difficulties caused by discontinuous characteristics of PWL elements. The resulting simulation algorithm is quite general, requires no prior knowledge of the circuit operation, is void of convergence problems, and yields relatively short simulation times on desktop PC machines. >

Analysis of new converter topologies, large converters, multi-converter systems, line commutated converters and electrical drive systems requires an appropriate global simulation tool. Because the dynamic model of AC machines is very complex due to the nonlinearities of the system, it is necessary to simulate the whole system containing an AC machine. A user friendly simulator must be able to handle complex systems as such electrical drives by dividing them in small interconnected sub-systems (converter-machine-regulator) assembled in a modular structure. The interconnection of these sub-systems must be done in a simple manner, without additional programming, using a graphic interface. The aim of this paper is to present a new interactive power electronic systems simulation package SIMUSEC "SIMUlation des Systemes Electrotechniques en Commutation", developed in the SIMULINK environment. This package permits simulation of power converters feeding passive loads or electrical machines either in open loop or in closed loop configurations. It also permits simulation of interaction between the converter-machine setups and between converters in a multiconverter system in order to study the conducted emissions. The built-in functions and tool boxes of SIMULINK facilitate the design and the analysis of high performance AC drive systems using this package.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Fast time-domain simulation of power electronic systems by using waveform-relaxation methods is presented. Algorithms for circuit partitioning, time windowing, and simulation scheduling are developed. Practical implementation of the partitioning algorithm based on modal analysis is also discussed. Feasibility and advantages of applying these methods to power electronic systems are demonstrated by simulation results for a series resonant converter and a boost zero-voltage-transition PWM converter.

With the increasingly high level of system integration it is becoming necessary to model not only electronic behavior of systems, but also interfaces to real world applications and the detailed physical behavior of elements of the system in question. The emergence of standard languages such as VHDL-AMS has made it possible to now describe a variety of physical systems using a single design approach and simulate a complete system. Application areas where this is becoming increasingly important include mixed-signal electronics, electro-magnetic interfaces, integrated thermal modeling, electro-mechanical and mechanical systems (including MEMS), fluidics (including hydraulics and micro-fluidics), power electronics with digital control and sensors of various kinds. In this paper, we will show how the behavioral modeling of multiple energy domains is achieved using VHDL-AMS, demonstrating with the use of examples how the interactions between domains takes place, and provide an insight into design techniques for a variety of these disciplines. The basic framework is described, showing how standard packages can define a coherent basis for a wide range of models, and specific examples used to illustrate the practical details of such an approach. Examples such as integrated simulation of power electronics systems including electrical, magnetic and thermal effects, mixed-domain electronics and mechanical systems are presented to demonstrate the key concepts involved in multiple energy domain behavioral modeling.

Before manufacturing, designers of power electronic systems use more and more computer simulation. The reduced computing cost and precision of power component models are essential for the accurate simulation of the power electronic systems to predict their electrical behavior. The accurate simulations of power electronic systems are based on the one hand on the knowledge of power component design parameters not published by manufacturers and on the other hand on a very good description of the arrangement and position of devices including the electromagnetic compatibility (EMC) contributions. In this chapter, through a study considering an experimental circuit of a switching cell including a Thyristor under test controlled by a MOSFET transistor, it is checked that a simple wiring inductance as the circuit wiring representation is insufficient to obtain accurate simulation results. Therefore, a suitable wiring model of the switching cell circuit is developed taking into account the wiring parasitic inductances of the layout and the mutual effects between them. Then, using the accurate model of the switching cell circuit, a detailed extraction procedure of the Thyristor design parameters is developed. This extraction procedure is based on a comparative study between experimental and simulated results, considering the physics of component. Finally a good agreement is obtained between experimental and simulated results confirming the validity of the developed extraction procedure as well as the suitable wiring model of the switching cell circuit.

In the simulation of power electronics systems, for reasons of computing time and convergence, it may be necessary to use ideal components which generate ideal voltage switchings (steep edges). However, in reality, these voltage variations are far from ideal and to reproduce a voltage closer to reality, it is necessary to model these variations. This is especially important for the study of residual voltage obtained by simultaneous switching, which are present in PWM strategies developped to reduce the impact of the common-mode voltage generated by 3-phase inverters. This paper is focused on the required model accuracy, in order to take into account these residues obtained by the synchronization of switching voltages.

In this work we present a FPGA implementation of the Latency Insertion Method (LIM) to perform simulation of power electronics systems with high switching frequencies (e.g. SiC based power converter with ƒ sw = 100 − 200kHz). We describe how LIM is used to model a buck and a three phase AC/DC converter and how a FPGA solver based on this approach is implemented. Simulation test performed on a Virtex-7 are presented. All real-time simulations are performed with time steps of 40ns and smaller.

Electro-thermal simulation of power electronic systems

Power electronic systems exhibit different types of fast- and slow-scale instabilities which limit the stable operating range of the parameters. It has been shown that the stability of complex power electronic systems can be fruitfully investigated using the Filippov method, where the stability of the system is given by the eigenvalues of the monodromy matrix, which is a combination of the state transition matrices through each subsystem and those across the switching events, called saltation matrix. In this paper we show that the components of the saltation matrix can be used to change the stability status of the system, and propose three specific techniques, which can be used individually or together to extend the range of stability significantly. The performance of these techniques are shown using line and load disturbances.

Power electronics are used to minimize losses in converting the energy produced by the generator in a wind turbine, and to drive motors that control the pitch and yaw of the wind turbine to ensure maximum power extraction. The power electronic system is based on a series of three-phase pulse width modulated (PWM) power modules consisting of IGBT power switches and associated diodes that are soldered to a ceramic substrate and interconnected with wirebonds. The design of the packaging and cooling of the power electronics is crucial to enhancing the energy efficiency and the reliability of the electronics, which generate heat loads in the hundreds of watts/cm2, and are often placed in harsh and inaccessible offshore environments. Without adequate heat removal, the increase in device temperature will reduce the efficiency of power electronic devices leading to thermal runaway and eventual failure of the entire power electronic system. Furthermore, the increased temperatures can lead to failure of the packaging elements as well. This paper will provide an overview of the fundamental packaging level mechanisms that can cause failures in the power electronic system. These include wirebond and lead fatigue, die attach fatigue, substrate cracking, and lead bonding fatigue.

Power electronic systems have become a key component in the efficient generation, distribution, storage, and use of energy. This increasingly places power electronic systems in harsh environments under elevated stress conditions where, in many cases, their reliable operation is now mission critical. The semiconductor material conventionally used, silicon, possesses limited capability for high temperature applications due to its small bandgap. Power electronic components based on wide bandgap (WBG) semiconductors, such as SiC and GaN, can be operated reliably at higher temperatures. Furthermore, WBG devices have higher breakdown voltages and switching frequencies, rendering them more ideal switches and rectifiers for highefficiency as well as low-volume and low-weight systems. Yet, new packaging concepts are required to make use of the high temperature capability of power electronic systems based on WBG semiconductor devices. In this paper, a summary of the progress in the development and commercialization of wide bandgap power components and power electronic systems is given. The properties of SiC and GaN components are compared to those based on silicon. The shortcomings of conventional power electronic packaging technologies are analyzed, and alternatives introduced and compared. An overview of research is given on Transient Liquid Phase Sintering (TLPS), a promising interconnect technology for the manufacturing of WBG and high temperature power electronic systems. TLPS is a liquid-assisted sintering process during which a low melting temperature constituent melts, surrounds, and diffuses in a high melting temperature constituent. Intermetallic compounds with high melting temperatures are formed by liquid-solid diffusion. Interconnect systems can be processed at low temperatures but are capable of operating at the high melting temperatures of the intermetallic compound. Different process approaches are contrasted and material systems compared. Latest results of research on paste-based low temperature TLPS are presented. The pastes assessed are based on the Cu-Sn and Ni-Sn material systems. It is shown that joints formed by TLPS remain strong up to 600°C and exhibit softening temperatures far higher than conventional interconnect technologies. They show minimum creep and possess very limited voiding. The process does not require an inert or reducing atmosphere or vacuum and is compatible with standard reflow soldering equipment. It shows good wettability to common metallizations such as Cu, Ni, Ag, and ENIG. This attach technology shows the potential to enable reliable operation of wide bandgap power electronic systems under high stress conditions.

Power electronics, a pivotal field orchestrating electrical energy flow in the modern world, deals with efficient conversion, control, and management of electrical power across diverse applications. While its scope encompasses circuits for energy conversion, its challenges include transporting electrical energy over extended distances. Focusing on electrical‐to‐electrical conversions, the goal is minimal loss for delivering maximum power. The article explores the intricacies of power electronics, presenting key equations, and concepts. The current global power electronics market witnesses growth, driven by demand for energy‐efficient technologies, renewables integration, and the rise of electric vehicles. Future trends indicate continued growth, driven by renewable energy systems, and electric vehicles. Wide bandgap semiconductors, play a crucial role, with ultra‐wide bandgap semiconductors like diamond emerging as potential disruptors. A comparative analysis of semiconductor properties reveals diamond's unique attributes. Despite its challenges, diamond shows promise for power electronic applications, with ongoing research on components like Schottky diodes. Thermal considerations, substrate limitations, and dislocation challenges are discussed, emphasizing the need for advancements to harness the full potential of diamond in power electronics. Finally, some inputs about the importance of overcoming these challenges for the successful integration of diamond in power electronic systems are given.

Batteries in a fuel cell power system are essential to provide the additional load demands during the sharp load transients. This necessitates a power electronics system, which would control the energy flow between the fuel cell stack, the battery and the load during the transient and in the steady-state. In this paper, a cost-effective and efficient power electronic system is proposed for a fuel cell based hybrid power system based on a distributed power electronics topology. The system includes a hierarchical controlling architecture, in which the master control optimizes the control parameters of the individual subsystem controls, which in turn optimizes the performance and efficiency of the overall system while nullifying the effects of load transients on the fuel cell stack subsystem. The power electronics system concept is further experimentally validated using a four module bidirectional DC-DC converter with Nexa PEM stack.

Modeling and Verification of Dependable Electronic Power System Architecture