Complex Power Electronic Systems Research Articles

Research on simultaneous switch and multiple switch processing methods

In the simulation of complex power electronic equipment containing multiple power electronic switches, it is often encountered that the same switch occurs several times in one step, or there are multiple switch actions in one step, that is, multiple switches. When the switching event occurs between two moments, because the voltage value can only be updated at the end of the simulation step, there is a cumulative error in the current obtained by the integration. In traditional electromagnetic transient simulation, the interpolation algorithm and its deformation are commonly used to solve this problem. However, due to the complexity of the conventional interpolation algorithm, it will seriously affect the efficiency in large-scale power grid simulation, and can only be applied to offline simulation, which cannot meet the needs of real-time simulation. In this paper, a method is presented to deal with synchronous switches and multiple switches, which can reliably solve the problem of synchronous switches and multiple switches encountered in real-time simulation of complex power electronic systems.

An Event-Driven Real-Time Simulation for Power Electronics Systems Based on Discrete Hybrid Time-Step Algorithm

Real-time (RT) hardware-in-the-loop (HIL) simulation aims to speed up the validation process for power electronic systems (PES). The complex PESs with high switching frequency constitute some of the most challenging applications in RT-HIL. Conventional RT-HIL relies on adding extra expensive computing hardware to achieve sub-microsecond step-size, reducing errors caused by unavoidable sampling delays. This paper proposes a CPU-based event-driven real-time (EDRT) simulation framework by improving the algorithm rather than using additional hardware. The framework consists of two parts: 1) the synchronous-cycle event detection (SCED) sampling method, which eliminates the delay error by detecting switching events; 2) the discrete hybrid time-step (DHT) numerical algorithm, which combines variable and fixed step-size simulation to improve the calculation efficiency and uses the ideal model to improve the modeling accuracy. The proposed framework is applied to a power electronic transformer (PET) with 24 switches and a 20 kHz switching frequency as a simulated case. Comparing the proposed simulation results with experimental results and other simulation results, the proposed EDRT framework can achieve the same numerical accuracy as the offline simulation but only requires 1/36 of the computation time. Furthermore, the hardware cost to achieve the same computational scale is reduced to 1/20 of the conventional HIL.

A Comparative Analysis of Computer-Aided Design Tools for Complex Power Electronics Systems

Companies working on semiconductors must currently assure the customers of not only the performance of the semiconductor device per se, but also its performance when it is implemented in a real board, therefore including the role of parasitic effects. It is therefore very important to evaluate, especially during the design phase, not only the single device, but the complete board and their mutual interactions. This consideration opens a new area of investigation in the field of electronic systems engineering. In the current literature, the problem of a software evaluation of parasitic dynamics and electromagnetic effects on printed boards is addressed from the point of view of researchers. Moreover, it is fundamental to have a complete view of the various tools that could be usefully adopted from the perspective of manufacturers. This is the main motivation of this technical note, which performs a comparative analysis of the most prominent software tools for printed circuit boards’ (PCBs) simulation. The main features, the key aspects, and the limitations of the software packages are analyzed in terms of the industrial design of power electronics devices, in order to ensure efficiency and fastness in the semiconductor market.

Guest Editorial: Special Section on Advanced Informatics for Energy Storage Systems in Electrified Vehicles and Smart Grids

E NERGY storage is a critical enabling technology for many complex mechatronic and power electronic systems, such as electrified vehicles, portable electronics, and smart grids. Unlocking its performance potential and reducing costs requires intelligent management systems, which are designed meticulously at the crossroads of multiple subjects, such as chemistry, materials, control theory, and electrical engineering. In addition to the benefits of improved efficiency and prolonged service life, advanced integration and management facilitate the storage of electrical energy from renewables, such as wind and solar energy, and accelerate a paradigm shift towards cleaner transport systems.

Avoiding instabilities in power electronic systems: toward an on‐chip implementation

The available controller chips for power electronic systems are used for specific transient and steady-state performances. In such systems, the parameter ranges for stable operation are delimited by slow-timescale as well as fast-timescale instabilities. The usual practice is to design the control loop based on the state-space averaging technique, which cannot predict the fast-timescale instabilities. In this study, the first attempt has been made to propose a new design of the controller chip that can suppress these instabilities, thus extending the stable operating range in the parameter space. For this, the authors make use of the Filippov method which can effectively predict both types of instabilities. In this approach, the stability of the system is obtained in terms of the state transition matrices across each subsystem and saltation matrices across each switching event. The basic idea is to exercise control over the saltation matrices to increase the stability margin of the periodic orbit. Since in the Filippov approach an increase in the number of switching events in a cycle does not increase the complexity of the analysis, the proposed controller chip will be particularly useful in complex power electronic systems such as interconnected converters, multi-input multi-output converters, resonant converters, micro-grids and so on.

Implementation of mathematical model of thermal behavior of electronic components for lifetime estimation based on multi-level simulation

Abstract The main purpose of the paper is the proposal of multi-level simulation, suited for the evaluation of the lifetime of critical electronic devices (electrolytic capacitors). The aim of this issue is to imagine about the expected operation of complex and expensive power electronic systems, when the failure of the most critical component occurs. For that reason, various operational conditions and various physical influences must be considered (e.g. mechanical, humidity, electrical, heat stress), where nonlinearities are naturally introduced. Verification of the proposal is given, whereby the life-time estimation of an electrolytic capacitor operated in a DC-DC converter during various operational conditions is shown. At this point electrical and heat stress is considered for lifetime influence. First, the current state in the field of mathematical modeling of the lifetime for electrolytic capacitors, considering main phenomena is introduced. Next, individual sub-models for multi-level simulation purposes are developed, including a thermal simulation model and electrical simulation model. Several complexities of individual models are mutually compared in order to evaluate their accuracy and suitability for further use. Proper simulation tools have been mutually linked and data transfer was secured, in order to have the possibility of investigation of a lifetime depend on the changes of various variables.

Investigation of thermal effects and lifetime estimation of electrolytic double layer capacitors during repeated charge and discharge cycles in dedicated application

The article is firstly focused on thermal analysis of electrolytic double layer capacitor (EDLC) operated at repeated cycles of charging and discharging. This process is mostly applied at switched mode power supplies (SMPS), where electrolytic capacitor within given period of operation acts as energy storage element (discharge period). Charging and discharging process of EDLC may cause additional heating, which consequently influences capacitor’s lifetime. This parameter (lifetime) is nowadays very important parameter of EDLC, because operational life of the most of complex power electronic systems is directly influenced by its most critical components, i.e., by electrolytic capacitors. In this paper, the theory necessary for capacitor analysis and analysis of heat transfer is presented. The particular aluminum electrolytic capacitor Nichicon is examined in the paper. The implementation of real model into COMSOL Multiphysics and consequent simulation settings are being described too. Based on the main parameters of target application, the simulation analysis is processed. These results are consequently verified by experimental measurements on a given sample of EDLC. Deviations between measured and simulated data are identified, and optimization steps for better accuracy are also given. Finally, the factors influencing the lifetime of electrolytic capacitors together with calculation of capacitor’s lifetime in power application are described. During lifetime estimation, heat transfer simulation modeling of capacitor is utilized. Presented approach offers acceleration of necessary variables identification, which are hardly to be identified with the use of measurements, e.g., capacitor’s core temperature. Thus, more accurate results regarding lifetime estimation can be achieved.

Simulation Based Teaching of Power Electronics

Simulation based approach to teach the Power Electronic course is proposed in this paper. The simulation tool is oriented towards Electrical and Electronics Engineering (EEE) students at the undergraduate level, enrolled in courses such as Power Electronics, Power Semiconductor drives or the like. The proposed teaching methodology is demonstrated by simulation example of a realistic converter system. The paper discusses the MATLAB/SIMULINK tool and the implementation of simulation for enhancing student learning ability of complex power electronic systems.

Ultralow Latency HIL Platform for Rapid Development of Complex Power Electronics Systems

Prototyping and verification of complex power electronics (PE) systems and control algorithms is a laborious and time-consuming process. Even when a low-power hardware model is assembled, it enables only a limited insight into the large number of operating points; changes in system parameters regularly demand hardware modifications and always there is the risk of hardware damage. The ultralow-latency Hardware-In-the-Loop (HIL) platform proposed in this paper combines the flexibility, accuracy, and ease of use of state-of-the-art-simulation packages, with the response speed of small power-hardware models. In this way, PE systems-optimization, code-development, and laboratory-testing can be combined into one step, which dramatically accelerates the pace of product prototyping. Low-power hardware-models also suffer from nonscalability, because some parameters such as electrical machine inertia cannot be properly scaled. However, HIL enables control prototyping that covers all operational conditions. In order to demonstrate HIL-based rapid development, the verification of an active damping algorithm for a permanent magnet synchronous generator (PMSG) cascade is performed. Two goals are set in this paper: to verify the developed HIL platform by means of comparison with a low-power hardware setup and then to emulate the real, high-power system in order to test the active damping algorithm.

Modeling and Simulation Five Level Inverter based UPFC System

paper deals with digital simulation of power system using five level inverter based UPFC to improve the power quality. The UPFC is capable of improving transient stability in a power system. It is the most complex power electronic system for controlling the power flow in an electrical power system. The real and reactive powers can be easily controlled in a power system with a UPFC. The circuit model is developed for UPFC using rectifier and inverter circuits. The control angle of the converters is varied to vary the real and reactive powers at the receiving end. The Matlab simulation results are presented to validate the model. KeywordsPower Quality, Statcom, Compensation and matlab simulink

Multi agent systems: An example of power system dynamic reconfiguration

The energy management in complex power electronic systems especially in case of limited power availability is challenging. In these systems generators, loads, energy storage devices and electrical power routers must be dynamically controlled and reco

Modelling and control of DC-DC converters

This tutorial article shows how the widely used analysis techniques of averaging and linearisation are applied to the buck or step-down DC-DC converter to obtain simple equations which may then be used for control design. Three common control methods are described. Their principal characteristics are illustrated using Matlab and the Simulink block diagram system along with experimental results. The analysis procedures described may be applied directly to other DC-DC converters and the principles may be extended to more complex power electronic systems.

Simulation of a non conventional high current low voltage power converter with EMTP

This paper presents, a novel, non-conventional 24-pulse converter for low-voltage high current applications based on a peculiar series connection of the primary zigzag windings. Simulation results confirmed experimental results and allowed second order phenomena to be taken into account. Even though EMTP software was not intended to simulate such a converter, it has been successfully used, showing to be a powerful simulation tool even in complex power-electronics systems.

Mathematical modelling of complex power electronic systems

In this paper, the topic of nonlinear difference equation modelling of complex power electronic systems is discussed. The concept of a Periodically Switched Coordinate System (PSCS) is proposed to simplify the analysis and design of the system. The nonlinear difference model can be obtained only under certain specified conditions, which are discussed in detail. The whole cyclic switch process is divided into three stages: nonperiodic, pseudo-periodic, and periodic. The nonlinear difference model can easily be obtained only after the non-periodic stage, and the eigenvalues of each linear state description can be expressed in terms of the parameters of the linear equation. The difficulty of the nonlinear difference modelling in the first stage is that the structure configuration changing modes depend on the initial condition and control vectors. The possibility of getting a model in the first stage is also discussed.