SIMULINK based simulations of power electronic 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.

Advanced control methods for power electronics systems

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.

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.

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. >

Precise testing of rotating electrical machines is very vital for determining accurate machine parameters and performance confirmation at various operating conditions. Traditional machine testing methods are time consuming and prone to various errors. Moreover, this requires skilled operator to perform the test, note down the readings and to do desired calculations. This paper presents all in one test bench that can perform all the standard tests on basic direct current (dc) and alternating current (ac) machines. The data obtained from these tests is used to calculate the equivalent circuit parameters, efficiency and to plot the characteristic curves of the machines. Various important parameters of the coupled machines are displayed on a mimic diagram present on the graphical user interface (GUI). LabViewis a very convenient tool to integrate the hardware for signal acquisition and control, which is used here for developing the GUI and control logic for the complete system. The complete system enables us not only to test and plot different characteristics of the machine but also to control, monitor and protect it from remote location with fault diagnosis.

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.

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

This work presents simulation of a sun tracking system that was developed for a Point Focus Fresnel Collector (PFFC) installed at King Saud University. The tracker is dual axis with a concentration ratio of 160 and a small acceptance angle of 2 degrees, hence a precise tracking control is required. Two control schemes were developed and tested, the open loop and closed loop. A sun position algorithm was used for open loop control whereas a sun sensor was used for closed loop control. The control system were simulated using Matlab/Simulink. It was found that open loop tracking is simpler to implement and consumes less power but is also less accurate and tracking error accumulates over time. On the other hand, closed loop control is more complicated to implement, consumes more power is much more accurate than open loop control. So, it is recommended to use the closed loop controller for PFFC system. The individual components of the control system were modelled using generic Simulink models. The complete model was operated in both open loop and closed loop configurations. The results of the models were analysed to estimate the operating limits of the tracker.

This paper introduces control system design based softwares, SIMNON and MATLAB/SIMULINK, for power electronics system simulation. A complete power electronics system typically consists of a rectifier bridge along with its smoothing capacitor, an inverter, and a motor. The system components, featuring discrete or continuous, linear or nonlinear, are modeled in mathematical equations. Inverter control methods,such as pulse-width-modulation and hysteresis current control, are expressed in either computer algorithms or digital circuits. After describing component models and control methods, computer programs are then developed for complete systems simulation. Simulation results are mainly used for studying system performances, such as input and output current harmonics, torque ripples, and speed responses. Key computer programs and simulation results are demonstrated for educational purposes.

Multiphase machines are AC machines characterized by a stator winding composed of a generic number n of phases. In today’s electric drive and power generation technology, multiphase machines play an important role for the benefits they bring compared to traditional three-phase ones (Levi, 2008; Levi et al., 2007). Such benefits have been widely highlighted by existing literature (Levi et al., 2007) and are mainly related to: an increased fault tolerance; higher power ratings achieved through power segmentation; enhanced performance in terms of efficiency and torque ripple. The use of multiphase machines is spreading both in small-power safety-critical applications as well as in very high-power industrial drives (Tessarolo et al., 2010), in electric-propulsion drives (Castellan et al., 2007) and power generation systems (Sulligoi et al., 2010). Regardless of whether they are used as motors or generators, multiphase electrical machines are almost always connected to power electronics systems (inverters for motors, rectifiers for generators), which interface them to the electric grid (Sulligoi et al., 2010; Castellan et al. 2008). Therefore, if the dynamic behaviour of a multiphase machine is to be predicted through simulations in the design and development stage, it is essential to do this by means of system-level simulations, where not only the electric machine is included, but also the power electronics and control systems that interact with it. Such a system-level simulation approach makes it difficult to use Finite-Element (FE) methods due to the complexity of the domain to be modelled and to the well-known computational heaviness of time-stepping FE simulations. Conversely, lumped-parameter models, to be implemented in the Matlab/Simulink environment, may provide designers with a powerful mean of analysis and investigation, provided that all the system components to be studied are modelled with an adequate level of accuracy and completeness. As concerns power electronics systems usually interfaced to multiphase machines, whether operating as motors or generators, the Matlab/Simulink environment offers wide and complete libraries where the designer can find reliable pre-defined blocks (for electronic switches, snubbers, diodes, etc.) to be used in building the application-related apparatus models. The same pertains to control and regulation blocks, which can be built up directly based on their transfer functions and logics. A possible criticality can be encountered when it comes to build the multiphase machine model. In fact, no predefined blocks are presently available in the Matlab/Simulink environment for this purpose. On the other side, building a dedicated user-defined machine

This paper provides an overview of multilevel converter topologies for grid connected applications. Different converter topologies such as Diode Clamp Converter (DCC), Capacitor Clamp Converter (CCC) and Chain Link Converter (CLC) are considered and compared from different aspects such as component sizing, complexity, efficiency and reliability. Thanks to its modular structure, the CLC appears as the most attractive topology for high power and high voltage applications. Single-Star Bridge-Cell (SSBC), Single-Delta Bridge-cell (SDBC), Double-Star Bridge-Cell (DSBC) and Double-Star Chopper-Cell (DSCC) are four basic subset topologies of CLC. A comprehensive comparison of these subset topologies for the CLC is provided for the particular application of grid connected converters. The problem of operation under unbalance grid conditions and the ability of this converter topology to inject negative sequence into the grid are discussed. It will be shown that due to the lack of a common DC link between phases, this converter topology presents limited negative sequence injection capability when the phase legs are connected in delta, while in case of star connection voltage balancing between the different cells of the converter becomes problematic due to the uneven current distribution among phases. This represents the main limitation of this converter topology, especially when used for load balancing and active filter applications.

Sensorless current-mode (SCM) control of DC-DC converters is a feedforward open loop scheme, which is compared to peak current-mode (PCM) control. Small signal model simulations of each controller are validated by experimental results. SCM offers improvements over the line disturbance rejection of current-mode control without feedback or current sensing. SCM is demonstrated to be useful in both open loop and closed loop configurations, by exploiting its inherent reference tracking and line disturbance rejection. In contrast, PCM requires a high gain two-loop control for voltage regulation.