Control Of Power Electronic Systems Research Articles

Evaluation of Different Methodologies for Wave Energy Conversion Systems Integration into the Power Grid Using Power Hardware-in-Loop Emulation

The ocean energy resources hold the promise of a sustainable solution within global efforts to diversify energy sources and mitigate climate change. Wave energy conversion (WEC) systems, as emerging technologies, offer adaptability and the potential to harness predictable wave energy. However, integration of WEC systems into a power grid brings challenges for system operators due to their nature of operation. Addressing these demands is a multilayered process that involves highly efficient power electronic devices, control systems, and efficient energy storage solutions. This paper specifically focuses on the methodologies of the grid integration of a specific wave energy conversion system—a point absorber developed by the company Sigma Energy. Proposed methodologies are experimentally tested using power hardware-in-loop (PHIL) emulation of a fully monitored and controlled small-scale microgrid equipped with a battery energy storage system (BESS), different emulators of loads, and distributed generators (DG).

Green Energy Storage Solutions: A Research

One of the key elements of decarbonizing global energy networks and integrating renewable energy sources is green energy storage technology. Energy Storage Systems (ESS), which store surplus produced electricity and make it available on demand, are essential for reducing fluctuations. Electromechanical, electromagnetic, thermodynamic, chemical and hybrid approaches have all been used in the development of energy storage technologies. A comprehensive list of current papers in the literature section is compiled to illustrate the range of advancements in this field. This paper reviews green energy storage systems, focusing on their primary uses. Power utilities will benefit from this thorough analysis of energy storage systems; the researchers choose the finest and newest energy storage technology based on its practicality and affordability. These days, several nations use energy storage systems to plan for future energy needs. Variations in solar radiation cause a solar photovoltaic generator to overproduce electricity. The implementation of a hybrid energy storage system would help to increase the reliability of solar-powered power generation. The microgrid is a crucial component of the smart grid network for solar installations. This study looks at the microgrid's energy storage system for photovoltaic systems. The topologies and storage system configurations of the microgrid are analyzed together with power electronic interference, control systems, and optimization of the energy storage system and renewable sources. a general technique for sizing the HESS of PV systems using design space as well as pinch analysis. HESS scales that link generator ratings to storage capacity are developed in the proper sizes by using pinch analysis to load and resources data.

Models for Stationary Noise Propagation in Multi-sampled PWM Power Electronic Control Systems With Decimation

Models for Stationary Noise Propagation in Multi-sampled PWM Power Electronic Control Systems With Decimation

Control of a lithium-ion battery interfacing input-voltage-controlled boost converter with virtual impedance compensation technique

Lithium-ion batteries are becoming increasingly popular for energy storage in various hybrid energy systems, hybrid ac/dc, micro-grid, e-mobility applications. However, due to the wide battery impedance range, the performance of lithium-ion battery interfacing dc-dc converter is affected, results in complicated task for design of this regulation. As the virtual impedance concept is increasingly used for the control of power electronic systems, this letter introduces virtual impedance into the Lithium-ion Battery interfacing boost converter controller, to reduce the impact of variable inner impedance. The proposed virtual-impedance based control structure, is derived with small-signal model of boost converter, and explained in detail in this letter. Finally, the performance of the strategy is verified on a lithium-ion battery pack equipped dc micro-grid.

Design and Evaluation of a Load Control System for Biomechanical Energy Harvesters and Energy-Removing Exoskeletons

Controlling the timing and magnitude of electricity production is a critical factor in reducing the metabolic cost of walking with an energy-removing exoskeleton. This article outlines a novel power electronic control system designed to apply a mechanical loading profile onto the user that extracts kinetic energy. This energy extraction assists the user's muscles, thereby providing metabolic assistance while simultaneously producing electrical power. This open-loop control system estimates the state of both the exoskeleton and the user's lower limbs and uses this estimation to identify and apply a desired knee flexion moment during the terminal swing phase. The control system was evaluated using human treadmill walking experiments and benchtop testing, which determined that the system could identify the user's stride period, ground contact timing, and the device's moment arm with high accuracy and precision. Furthermore, the system could apply the desired cable force within +2.6 and −2.3 N and the muscle-centric knee moment profile within +0.05 and −0.04 N·m. Through proper load control, a user would benefit from walking with an energy-removing exoskeleton, regardless of the need for portable power.

Steady-State Error Compensation for Reinforcement Learning-Based Control of Power Electronic Systems

Steady-State Error Compensation for Reinforcement Learning-Based Control of Power Electronic Systems

Design and Implementation of Three-Phase Smart Inverter of the Photovoltaic Power Generation Systems

The main purpose of this paper is to conduct design and implementation on three-phase smart inverters of the grid-connected photovoltaic system, which contains maximum power point tracking (MPPT) and smart inverter with real power and reactive power regulation for the photovoltaic module arrays (PVMA). Firstly, the piecewise linear electrical circuit simulation (PLECS) power electronic real-time control system was applied to construct the simulation and actual test environment for the three-phase mains parallel photovoltaic system, where the KC200GT photovoltaic module was used to form a 1600 W system for conducting the simulation. For enabling the PVMA to output the maximum power in terms of both insolation and ambient temperature, where the perturbation and observation (P&O) method was used for MPPT. Then, the voltage-power control technology was added to the grid-connected photovoltaic inverter. When the grid voltage p.u. value is between 1.0 and 1.03, the smart inverter starts voltage-power regulation, reducing the real power output to 1440 W, and absorbing the system’s reactive power to 774 VAr. The power factor of the grid system end is controlled to 0.9 (lagging), and the grid voltage is reduced to norminal value 220 V. If the grid voltage p.u. value is between 0.97 and 1.0, the smart inverter starts voltage-power regulation, controlling the output real power to 1440 W and the reactive power to the system to 774 VAr, so that the power factor of the system end is controlled to 0.9 (leading), and the grid voltage is increased to norminal value 220 V. Finally, the results from the simulation and actual test were used to demostrate the effectiveness of the regulation performance of the smart inverter.

Guest Editorial: Special issue from 9th IET Renewable Power Generation Conference

The 9th IET Renewable Power Generation Conference took place online in March 2021, having originally been intended to take place in Dublin, Ireland some months earlier. A major motivation for the conference was the recognition of the challenges and possibilities arising from increasing renewable shares in many countries, and the critical need for cost-effective, reliable, and robust solutions as part of the ongoing transformation of our power and energy systems. Despite the restrictions of the pandemic, approximately 70 papers were successfully presented at the conference across 15 oral and poster sessions, covering a wide range of themes including low inertia power systems, wind power plant modelling and control, renewable energy forecasting, distribution network operation and long-term planning, power system protection, electricity markets and system services etc. Subsequent to the conference, a number of the authors of the presented papers were invited to submit an extended version of their papers to a special issue of the IET RPG journal. Ultimately, after a thorough peer review process, 16 papers were accepted for the special issue, which have been grouped here under five main themes: electrical network operation and planning; power electronic converter control systems; flexibility/frequency support measures and electricity markets; power system security, protection and monitoring; and tidal stream energy.

Advanced Perspectives for Modeling Simulation and Control of Power Electronic Systems

Power electronic systems have become a major issue related to advancements in consumer and industrial electronics [...]

FPGA Implementation for Rapid Prototyping of High Performance Voltage Source Inverters

Field-programmable gate array (FPGA) is a powerful platform that can play an essential role in high-performance digital control of power electronics systems. However, the FPGA system’s design is quite different from that of a traditional microprocessor or a digital signal processor (DSP). Instead of sequential programming using high-level languages, such as C/C++, FPGA controller implementation requires a hardware description language (HDL) such as Verilog and VHDL, which requires extensive verification and optimization during the design process. This paper proposes a systematic FPGA design methodology with optimum resource utilization for rapid prototyping of high-performance power electronics applications to facilitate the widespread adoption of FPGA technology in power electronics. The FPGA controller design is concurrent with the power stage and utilizes high-level synthesis (HLS) tools and Simulink code generation toolbox. This paper covers the detailed design, implementation, and experimental validation of two specific applications, i.e., an active power filter (APF) and a motor emulator (ME), demonstrating the generalized features of the methodology. Employing fundamentally different control structures, both application examples achieve ultra-high current control bandwidth leveraging SiC MOSFETs switching at no less than 100 kHz.

Artificial Intelligence Techniques: How Can it Solve Problems in Power Electronics?: An Advancing Frontier

Artificial intelligence (AI) techniques have recently emerged as the powerful and advancing frontier in power electronics and their impact in the next generation of power electronics appears to be tremendous. The advent of AI has brought a challenge to the engineers specialized in power electronics which is already a complex, interdisciplinary and fast-moving technology. The AI provides very powerful tools for design, simulation, control, estimation, fault diagnostics, and fault-tolerant control of power electronic systems, which are particularly important in modern smart grid and renewable energy systems (RESs) in addition to its applications in traditional power electronics and motor drives area. A smart or intelligent grid is basically an advanced electric power grid of tomorrow using state-of-the-art technologies in power electronics, power systems, computers, communications, information, AI and cyber that will improve the system availability, reliability, power quality, energy efficiency, and security with optimum resource utilization and economical electricity to the consumers.

An Automated Semi–symbolic State Equation Generation Method for Simulation of Power Electronic Systems

Computer-aided analysis is playing an important role in the design and control of power electronic systems. A discrete-state event-driven (DSED) framework with state-space modeling has been proposed recently for accurate and efficient off-line simulation. Nevertheless, automated equation formulation for arbitrary circuits is also required to develop the DSED framework toward general simulation software. However, the traditional state equation generation method is very time-consuming, especially for large-scale systems due to the variable topologies brought by switching events. In this article, an automated semi-symbolic state equation generation method is proposed. Based on the switching function modeling of basic switching legs, an explicit function from switching states to state equation matrices is given, which reduces the computational cost without sacrificing any accuracy. The operating and topological characteristics of power electronics systems are utilized for further optimization. The proposed method greatly increases the simulation efficiency of power electronic systems, especially for large-scale systems. Two cases of the 2 MW 4-port solid-state transformers with different system scales are simulated with the proposed method under the DSED framework. About 700-fold and 1200-fold acceleration is achieved compared with one fast-speed commercial software, where the proposed method contributes 50-fold and 110-fold acceleration in the two cases, respectively.

Minimization of Network Induced Jitter Impact on FPGA-Based Control Systems for Power Electronics through Forward Error Correction

In modular distributed architectures, the adoption of a communication method that is at the same time robust and has a low and predictable latency is of utmost importance in order to support the required system dynamics. The aim of this paper is to evaluate the consequences of the random jitter on machine drives distributed control, caused by the messages’ re-transmission in case of an error in the received data. To achieve this goal, two different Forward Error Correction (FEC) techniques are introduced in the chosen protocol, so that the recipient of the message can correct random errors without the need of any additional round trip delays needed to request and obtain a re-transmission. Experimentally validated simulations are used to evaluate the impact of random network derived jitter on a real world closed loop control system for distributed power electronic converters.

Supervised Imitation Learning of Finite-Set Model Predictive Control Systems for Power Electronics

In the past years, finite-set model predictive control (FS-MPC) has received a lot of attention in the power electronics field. Due to very simple inclusion of the control objectives and straightforward design, it has been adopted in a lot of different converter topologies. However, computational burden often imposes limitations in the control implementation if multistep predictions are deployed or/and if multilevel converters with many possible switching states are used. To remove these limitations, we propose to imitate the predictive controller. It is important to highlight that the imitator is not intended to improve the dynamic or steady-state performance of the original FS-MPC algorithm. In contrast, its key role is to keep approximately the same performance while at the same time reducing the computational burden. Our proposed imitator is an artificial neural network trained offline using data labeled by the original FS-MPC algorithm. Since the computational burden of the imitator is not correlated with the complexity of the FS-MPC algorithm it emulates, implementation of much more complex predictive controllers is made possible without prior limitations. The proposed method is validated experimentally on a stand-alone converter configuration and the results confirm a good match between the imitator and the predictive controller performance. Simulation models of both controllers are provided in the supplementary files for three different prediction horizons.

Model Predictive Control of Power Electronic Systems: Methods, Results, and Challenges

Model predictive control (MPC) has established itself as a promising control methodology in power electronics. This survey paper highlights the most relevant MPC techniques for power electronic systems. These can be classified into two major groups, namely, MPC without modulator, referred to as direct MPC, and MPC with a subsequent modulation stage, known as indirect MPC. Design choices, and parameters that affect the system performance, closed-loop stability, and controller robustness are discussed. Moreover, solvers, and control platforms that can be employed for the real-time implementation of MPC algorithms are presented. Finally, the MPC schemes in question are assessed, among others, in terms of design, and computational complexity, along with their performance, and applicability depending on the power electronic system at hand.

Fuzzy Logic-Based Pulse Density Modulation Scheme for Mitigating Uncertainties in AC–AC Resonant Converter Aided Induction Heating System

Induction heating (IH) applications aided by power electronic control system have become very attractive in the recent past. The power electronics circuits succumb to severe switching loss, lower power density if proper switching methodology is not adhered. A state of uncertainty is indispensable in IH application as the power required by the load varies depending upon the nature of work piece. This uncertain issue makes the selection of the control algorithm and controller very vital. The mundane controllers may not be compatible to combat the uncertainties and leads to exhibit dynamic problems say transients, peak overshoot and poor response. Henceforth, the IH system requires a superlative converter topology and control scheme in order to have reduced switching loss and to improve the system performance there by negating the uncertainties. Here, in this work, a direct AC–AC boost resonant converter fed by pulse density modulation (PDM) is realized in a single stage mode. A fuzzy logic-based PDM control technique improves the efficiency and provides the versatile power control with reduced time domain specifications for dynamic changes in load. The proposed system has been studied using MATLAB/SIMULINK and validated using a hardware prototype employing dsPIC30F4011 microcontroller. The results reveal that efficient control over power can be accomplished by varying the density of the switching pulses, and thereby the efficiency is enhanced even with reduced component count. Also, the single-stage conversion is effective than its two-stage counterpart.

Instantaneous Phase Voltage Sensing in PWM Voltage-Source Inverters

The output voltage of power electronic converters is a very important quantity for dynamic control of power electronic systems. In electrical drives without electromechanical position or speed sensor, the terminal reference voltage is used to obtain the rotor position. Dead-time effects and semiconductor voltage drop lead to distortion in the actual output voltage and degrade the control performance when the back electromotive force magnitude is low. Thus, for stable low-speed operation, output voltage sensing becomes necessary. Due to the switching nature of power electronic systems, this is not a trivial task, especially when instantaneous measurement of the terminal voltage is required. In this paper, an instantaneous switching-period average voltage sensing technique is proposed that utilizes a combined approach of oversampling and filtering. Based on the theoretical analysis of the sampling- and filter-induced measurement distortion, a general solution for an optimal filter design is derived. The additional sensing circuit is integrated into the low-side gate driver of the converter outputs. This paper includes details about the hardware implementation and extensive verification measurements.

A Novel Power Control Technique for Series Resonant Inverter-Fed Induction Heating System with Fuzzy-Aided Digital Pulse Density Modulation Scheme

The research on Induction heating aided by power electronic control system is so vivacious in recent past. The selection of switching techniques remains to be the bottleneck for power engineering research as inappropriate selection may result in relentless switching loss, conduction loss, high current ripple, and lower power density. Therefore, modern design emphasizes multi-output resonant inverters, which not only have high efficiency but also facilitate resonant switching. This work proposes a single-stage ac–ac dual half-bridge series resonant inverter, with reduced number of switching devices. The proposed converter is controlled with fuzzy logic-aided digital pulse density modulation technique which aids in power control task. This intelligent power control scheme improves the system efficiency with less time-domain specifications. The simulation of the work is realized in MATLAB/Simulink arena, and hardware circuits are validated using dsPIC30F4011 microcontroller. The results reveal that the proposed schemes are highly viable and effective for the rendered application.

Logic-Based Methods for Intelligent Fault Diagnosis and Recovery in Power Electronics

This paper presents generalized logic-based methods for intelligent fault diagnosis in power electronic converters based on correlation between faults and basic measurements. Fault recovery is then applied based on this correlation by using necessary signals and quantities from existing measurements. The main purpose of the proposed fault diagnosis methods is for power electronic systems to survive from fault conditions that could occur in various components, to cope with the notion of a smart grid and extend their lifetime. The proposed methods are online, i.e., real-time or near-real-time, and can be applied to any power electronic system. Existing intelligent control of power electronic systems along with various short- and open-circuit faults in major power electronic components are reviewed. Two methods are established to diagnose faults and engage redundancy for fault recovery with one method using combinational logic and another using fuzzy logic. In both methods, two quantities are observed for each of the measured signals: 1) the signal's average value and 2) the signal's RMS value. Total harmonic distortion is also used in some simulations but is not required in experimental implementation. A systematic methodology to reduce the number of measured quantities while maintaining effective diagnosis is introduced. A solar PV microinverter in standalone mode is used as an example testing platform for the proposed methods. A simulation model is experimentally validated and the effect of each fault on different voltage and current measurements are observed, then both methods are tested in simulation and hardware. Results show the ability of both methods to diagnose several faults in the inverter's power stage along with their ability to engage redundancy for fault recovery.

Guest Editorial Special Issue on Distributed Generation

The addition of a more distributed generation in the electrical grid is poised to rapidly improve the sustainability of electric power generation and energy security, while reducing cost. The electrical grid is an aging century-old large infrastructure mainly based on large (GW) electrical central power stations that have slow dynamics. Grid integration of distributed generators requires advanced power electronic conversion and control systems to successfully incorporate energy sources and storage systems with high efficiency, power quality, and reliability. The emerging adoption of distributed grid-connected converters brings unprecedented new capabilities and opportunities to support the electrical grid and increase the flexibility of distribution systems (existing ac and forthcoming dc). Future and novel technologies involved in the advancement of renewable and CO2 neutral distributed generation will include work in the areas of topologies, modulation, controllers, energy storage, and power quality, among other technical solutions to enable high penetration and reliable operation. As well, new innovations foresee the use of power converters to provide new ancillary functions for grid support and adopt evolving standards and grid codes.