Power electronics system modeling and simulation

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.

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>

In this paper, an implementation of a space vector modulation (SVM) based hysteresis current controller (HCC) for the control of a three-phase high power factor rectifier is proposed. The SVM-based HCC scheme is designed, simulated and implemented. The technique combines the best features of the SVM and HCC techniques. The controller determines a set of state space vectors from a region detector and then applies a space vector selected according to HCC. A set of space vectors in a region, including the zero space vector for a reduced number of switchings, is determined from the output signals of three comparators with a hysteresis band a little larger than that of the main HCC. A simple experimental implementation is proposed and the simulation and experimental results of the SVM-based HCC are discussed in the paper.

This paper introduces a new method of modeling microcontroller-based systems in a non-real-time electromagnetic transient (EMT) simulation. Presently, power electronic control system simulation relies chiefly on either simplified control block models in a non-real-time simulator or real-time hardware-in-loop simulation. Migrating control block models from the simulated design to actual microcontroller hardware requires significant additional effort. Real-time hardware-in-loop simulation requires complex interfacing using costly real-time hardware. The method described in this paper replaces control system blocks in non-real-time simulation with actual microcontroller code. The method enables both software-in-loop simulation and processor-in-loop co-simulation, eliminates the drawbacks of the simulation methods described above, and allows direct optimization of the actual controller hardware. The method is demonstrated by simulations of a three-phase ac motor controller in both software-and processor-in-loop configurations. The simulations are verified by laboratory results obtained using the tuned microcontroller hardware to implement a control system for a 3-phase ac motor.

In order to overcome the shortcomings of traditional AC-DC-AC electrical driving systems, a dual-PWM method for the three-level voltage source converter to drive an induction motor (IM) is proposed in this chapter. In the rectifier part, this chapter presents the inner current-loop and the outer voltage-loop control strategy based on voltage space vector (SVPWM); in the inverter part, this chapter proposes the current-loop and the speed-loop control strategy based on SVPWM and rotor flux oriented. By applying the dual-PWM method, the system can get unity input power factor, minimize both input and output current harmonics, achieve bidirectional flow of energy, and enhance dynamic performance of the speed control. At last, both simulation and experimental results verify the feasibility and usefulness of this control method.

Permanent Magnet Synchronous Motors (PMSMs) are extensively employed in various applications, including electric vehicles, industrial machinery, and precision motion control systems, owing to their high efficiency, power density, and excellent controllability. The performance of these motors is strongly influenced by several design parameters, notably the slots-per-pole-per-phase ratio, stator winding configuration, permanent magnet arrangement, and slot opening width. This study investigates the impact of each of these parameters on key motor performance metrics, such as output torque and torque ripple. In this study, the effects of each parameter on output torque and torque ripple are examined individually and in combination. Simulation results demonstrate that appropriate optimization of these factors can significantly enhance the motor's electromagnetic performance. Based on these findings, an improved motor structure is proposed, and its performance is compared to that of the initial design.

System simulation in power electronics is characterized by a large number of different circuit elements. One can generally distinguish between passive and active components, any kind of switch (i.e. power semiconductors), control elements and electrical machine. The behaviour of these elements is defined by different time constants. A PWM drive can operate with a fundamental frequency of some kilohertz feeding an electrical drive with a time-constant of some seconds. This high ratio shows that a large number of simulation steps must be carried out in order to obtain useful information. Both the large number of elements acting in parallel and the large number of switching transients during the simulation make it necessary to take a close look at computer simulation models with respect to accuracy and speed. The primary objective is to find models which allow fast system simulation.

In the traditional direct torque control (DTC) of induction motor, the low order harmonic component of stator current is very large when the motor is running at low speed. It leads to high torque ripple of motor in low speed. To solve this problem, a new control method has been proposed in this paper. Base on the traditional DTC method, electromagnetic torque and flux models have been analyzed. To further improve the torque response and reduce the torque ripple, fuzzy logic concept has been introduced into the flux model. The method of dynamic adjustment of the torque hysteresis amplitude is proposed. In this model, fuzzy variables are the speed and stator current error. Through the rationalization of fuzzy classification, the choice of voltage space vector is optimized. The results of simulation and experiment show that the method can not only improve the speed of torque response, and the problem of torque ripple can be effectively solved. In the whole speed range, the performance of dynamic and static is better than that of the conventional DTC.

This study performed reliability-based robust design optimization (RBRDO) of stator and rotor shape of the IPM type electric motor to reduce the torque ripple considering uncertainties. A metamodel based on the design of experiments results, which was calculated by using 2-D electromagnetic finite element analysis, was used to calculate manufacturing uncertainties and material property distribution. As a result, the mean torque ripple of the optimum electric motor design was reduced by 56.4 % and the robustness was increased by 61.8 % compared with the initial design. The RBRDO design was compared with the designs of deterministic design optimization and reliability-based design optimization, and it was shown that, by using the RBRDO method, the optimum IPMSM can be designed to satisfying not only the minimum torque ripple but also the robustness and the reliability of output torque and torque ripple.

A kind of Direct Torque Control System based on ADRC and SVPWM for asynchronous motor is designed. For the purpose of restraining the ripple of electro-magnetic torque and flux linkage, SVPWM is used in the system as an improvement. At the same time, PI controller is replaced by ADRC controller to overcome its disadvantages. Simulation of SVM-DTC system based on ADRC is realized. Simulation results have shown that the system can restrain the ripple of electro-magnetic torque and flux linkage effectively. It also has a good resistance to disturbance caused by the change of load torque.

In an electrohydraulic total artificial heart developed at the National Cardiovascular Center (Osaka, Japan), two blood pumps are pushed alternatively by means of the bidirectional motion of a brushless DC motor for pump systole and diastole. Improvement in the dynamic response of the motor is very important to obtain better pump performance; this was accomplished by using power electronic simulation. For the motor to have the desired dynamic response, it must be commutated properly and the damping ratio (zeta), which represents transient characteristics of the motor, must lie between 0.4 and 0.8. Consequently, all satisfactory specifications with respect to power consumption must be obtained. Based on the simulated results, the design criteria were determined and the precise controller designed to reduce torque ripple and motor vibration, and determine motor stop time at every direction change. In in vitro tests, evaluation of the controller and dynamic response of the motor was justified in terms of zeta, power consumption, and motor stop time. The results indicated that the power consumption of the controller and the input power of the motor were decreased by 1.2 and 2.5 W at zeta = 0.6, respectively, compared to the previous system. An acceptable dynamic response of the motor, necessary for the reduction of torque ripple and motor vibration, was obtained between zeta = 0.5 and zeta = 0.7, with an increase in system efficiency from 10% to 12%. The motor stop time required for stable motor reoperation was determined to be over 10 msec, for a savings in power consumption of approximately 1.5 W. Therefore, the improved dynamic response of the motor can contribute to the stability and reliability of the pump.

Reactive current compensation is a method to improve the load power factor by locally supplying the reactive current requirement of the load using shunt compensators. Current controller of shunt compensators is usually designed using conventional PI controllers, in spite of the improved dynamic performance offered by hysteresis controllers. Conventional hysteresis current controller brings up different issues like variable switching frequency, non-optimal switching etc. Because of these issues, hysteresis current controllers are generally not preferred by the researchers even though it is easy to implement. This paper proposes a constant switching frequency hysteresis current controller for shunt compensators. Simulation results are presented to validate the effectiveness of proposed controller.

Power electronics systems are non-linear systems, which consume more reactive power and also the loads they feed are mostly inductive loads which leads to a poor power factor. Various compensation techniques are available to bring the power factor nearer to unity. In this paper, a novel compensator is proposed, where in-phase and quadrature components of the supply current are vector-controlled. Implementation of this compensator in a power electronic system operating with a very poor power factor (and hence high THD), shows that the system then draws a leading current. A conventional power electronic system, A conventional power electronic system with one of the traditional static VAR compensators and the conventional power electronic system incorporated with the proposed compensator are simulated and the simulation results are obtained. It is shown that the proposed method offers only 0.7% THD, which also implies that the power factor is improved.

As the transportation sector is promoting electric vehicle technology, the demand for high torque machine is increasing. For high performance the electrical machine drives needs to be operated above 400V DC bus. At high voltage the low inductance property of brushless DC (BLDC) motor can cause high torque ripple which is unsuitable for drive operation. In this paper, a new multiband hysteresis current controller (MHCC) for minimizing the torque ripple in a three level brushless DC motor drive is presented. Hysteresis controller are widely used for their good dynamic response, ease of implementation and overload current protection. Hysteresis current control is well established for two level inverters. In this paper, a three level inverter with MHCC is implemented for improving the current tracking and to reduce the torque ripple. The simulation results thus obtained in MATLAB/Simulink environment is encouraging. In depth analysis to evaluate the performance of the proposed current control strategy is also presented.

In this paper, an optimal basic speed controller for switched reluctance motor (SRM) based on Elitist-Mutated Multi-Objective Particle Swarm Optimization (EM-MOPSO) with good accuracies, and performances is presented. The control mechanism is composed of a Proportion-Integration (PI) speed controller and a hysteresis current controller. Because of nonlinear characteristics of a SRM, EM-MOPSO is used to tune coefficients of PI speed controller, turn on and turn off angles along with maximum value of the phase current by applying a multi-objective function, including both Integrals Squared Error (ISE) of speed and torque ripple. This EM-MOPSO based controller simulated in SIMULINK/MATLAB software for a four phases, 4-kw SRM. The performances of the EM-MOPSO and PSO algorithm in tuning the controller parameters are compared with each other. Simulation results show that the EM-MOPSO based controller can better improve SRM performance such as torque ripple, dynamic response and copper losses.