Permanent magnet synchronous motors (PMSMs) are known as highly efficient motors and are slowly replacing induction motors in diverse industries. PMSM systems are nonlinear and consist of ...time-varying parameters with high-order complex dynamics. High performance applications of PMSMs require their speed controllers to provide a fast response, precise tracking, small overshoot and strong disturbance rejection ability. Sliding mode control (SMC) is well known as a robust control method for systems with parameter variations and external disturbances. This paper investigates the current status of implementation of sliding mode control speed control of PMSMs. Our aim is to highlight various designs of sliding surface and composite controller designs with SMC implementation, which purpose is to improve controller’s robustness and/or to reduce SMC chattering. SMC enhancement using fractional order sliding surface design is elaborated and verified by simulation results presented. Remarkable features as well as disadvantages of previous works are summarized. Ideas on possible future works are also discussed, which emphasize on current gaps in this area of research.
This paper investigates speed regulation of permanent magnet synchronous motor (PMSM) system based on sliding mode control (SMC). Sliding mode control has been vastly applied for speed control of ...PMSM. However, continuous SMC enhancement studies are executed to improve the performance of conventional SMC in terms of tracking and disturbance rejection properties as well as to reduce chattering effects. By introducing fractional calculus in the sliding mode manifold, a novel fractional order sliding mode controller is proposed for the speed loop. The proposed fractional order sliding mode speed controller is designed with a sliding surface that consists of both fractional differentiation and integration. Stability of the proposed controller is proved using Lyapunov stability theorem. The simulation and experimental results show the superiorities of the proposed method in terms of faster convergence, better tracking precision and better anti-disturbance rejection properties. In addition, chattering effect of this enhanced SMC is smaller compared to those of conventional SMC. Last but not least, a comprehensive comparison table summarizes key performance indexes of the proposed controller with respect to conventional integer order controller.
The uses of grid-connected photovoltaic (PV) inverters are increasing day by day due to the scarcity of fossil fuels such as coal and gas. On the other hand, due to their superior efficiency, lower ...cost, smaller size, and lighter weight when compared to inverters with transformers, transformerless inverters for low-voltage single-phase grid-tied photovoltaic (PV) systems have recently attracted more interest. However, there are some specific challenges, especially leakage current issues, which must be adequately addressed to ensure the safety standards of the grid codes. A variety of topologies has been presented in the literature to eliminate the leakage current using the decoupling or clamping technique. However, choosing an appropriate topology after comparison is challenging because each topology has a unique set of parameters. In this paper, the authors have selected a common set of parameters and simulated all the selected eighteen well-known topologies in MATLAB/Simulink to fairly analyze and compare their common mode characteristics and other output parameters. In addition, the power loss distribution of every switch of each of the eighteen topologies was calculated and presented to better understand the insight of the topologies.
Growing electricity demand, the deployment of renewable energy sources and the widespread use of smart home appliances provide new opportunities for home energy management systems (HEMSs), which can ...be defined as systems that improve the overall energy production and consumption of residential buildings by controlling and scheduling the use of household equipment. By saving energy, reducing residential electricity costs, optimizing the utilization rate and reliability of utility companies' power systems, and reducing air pollution for society, HEMSs lead to an enhancement in the socioeconomic development of low-carbon economies. This review aims to systematically analyze and summarize the development trends and challenges of HEMSs in recent years. This paper reviews the development history of the HEMS architecture and discusses the characteristics of several major communication technologies in the current HEMS infrastructure. In addition, the common objectives and constraints related to scheduling optimization are classified, and several optimization methods in the literature, including various intelligent algorithms, have been introduced, compared, and critically analyzed. Furthermore, experimental studies and challenges in the real world are also summarized and recommendations are given. This paper reveals the trend from simple to complex in the architecture and functionality of HEMSs, discusses the challenges for future improvements in modeling and scheduling, and shows the development of various modeling and scheduling methods. Based on this review, researchers can gain a comprehensive understanding of current research trends in HEMSs and open up ideas for developing new modeling and scheduling approaches by gaining insight into the trade-offs between optimum solutions and computational complexity.
The exponential increase in the frequency and intensity of high impact low probability weather‐related events have pivoted the paradigm of research pertaining to power systems towards resilience. ...Power system is considered as a critical infrastructure, directly linked to the nation's economy, security and health. Therefore, recent researchers have proposed several techniques to enhance the resilience of power systems. In those techniques, critical loads have been considered independent in nature and different metrics have been proposed to evaluate the resilience of the network. To enhance the resiliency, this paper incorporated distributed generators in the distribution network and critical loads are modelled interdependently. Furthermore, a novel resilience metric is proposed in this paper to evaluate the resilience of a distribution system. The proposed model is formulated as a mixed integer second‐order cone programming problem and the efficacy of the proposed model is evaluated on IEEE 33‐ and 69‐bus systems. The competence of the proposed resilience metric is evaluated after comparison with existing resilience metrics.
In recent decades, flash floods have become more common because of climate change and are considered a substantial risk for many cities worldwide. This catastrophic natural hazard presents a ...significant threat to critical infrastructure in urban areas, particularly the power distribution system. As modern societies are much more dependent on electrical energy these days, it is essential and imperative to make existing distribution systems resilient against flash flooding. Although researchers in this area have proposed various algorithms to impart resilience to a distribution system, however, the focus in these works is on wind‐related events such as hurricanes, cyclones, and windstorms. Therefore, here, the spatiotemporal effects of a flash flood on the distribution system are modelled using a grid‐based hydrodynamic model. The evolving line faults are then included in the proposed resilience‐oriented time horizon‐based service restoration model that also considers dynamic load demand, heavy uncertainties related to renewable generation, and interdependence among critical loads. Finally, the resilience of the distribution system's response is assessed using an operational resilience metric. The efficacy of the proposed framework is evaluated on IEEE 33‐bus and 69‐bus systems and the results show that the model provides an efficient restoration solution despite increased complexity caused by varying conditions.
The spatiotemporal effects of a flash flood on the distribution system are modelled using a grid‐based hydrodynamic model. The evolving line faults are then included in the proposed resilience‐oriented time horizon‐based service restoration model that also considers dynamic load demand, heavy uncertainties related to renewable generation, and interdependence among critical loads. Finally, the resilience of the distribution system's response is assessed using an operational resilience metric.
Summary
Hybrid energy storage system (HESS) has emerged as the solution to achieve the desired performance of an electric vehicle (EV) by combining the appropriate features of different technologies. ...In recent years, lithium‐ion battery (LIB) and a supercapacitor (SC)‐based HESS (LIB‐SC HESS) is gaining popularity owing to its prominent features. However, the implementation of optimal‐sized HESS for EV applications is a challenging task due to the complex behavior of LIB and SC under different driving behaviors. Besides, the power electronics (PE) converter configurations and system‐level optimizations, include component sizing (CS) and power‐energy management strategy (PEMS), are essential for developing efficient HESS. Therefore, this paper reviews existing LIB‐SC HESS, different possible combinations of CS and PEMS, generalized algorithm formulation, and algorithms used for both CS and PEMS. The current issues of LIB‐SC HESS regarding the performance in EV applications, PE converters, and optimization algorithms are also analyzed. In addition, future recommendations for the development of efficient LIB‐SC HESS are provided to inspire researchers for further studies.
Highlights
Lithium‐ion battery (LIB) and supercapacitor (SC)‐based hybrid energy storage system (LIB‐SC HESS) suitable for EV applications is analyzed comprehensively.
LIB‐SC HESS configurations and suitable power electronics converter topologies with their comparison are provided.
System‐level optimization of LIB‐SC HESS and generalized steps involved in implementing the optimization algorithm for component sizing (CS) and power‐energy management strategy (PEMS) are discussed.
A rigorous study on CS and PEMS is presented to develop efficient LIB‐SC HESS.
Current challenges and future recommendations for the development of LIB‐SC HESS for EV applications are provided.
Photovoltaic (PV) systems provide a reliable green energy solution by improving maximum power point tracking (MPPT) methods to achieve maximum power under various weather conditions. Among MPPT ...algorithms, the perturbation and observation (P&O) algorithm is widely used in PV systems due to its simple implementation. However, the algorithm has limitations in terms of tracking convergence speed, steady-state oscillation, and drift problem during sudden irradiance variations. This paper proposes a modified P&O algorithm for optimal MPPT under different weather conditions. A new strategy is used to control the duty cycle perturbation step size, which provides faster tracking convergence. The algorithm detects the attainment of the steady-state oscillation in a simple way and then stops the perturbation process. This eliminates the oscillation around the MPP. Moreover, the algorithm can detect the change in solar irradiance immediately and solve the drift problem without additional sensors. The proposed method was simulated using MATLAB/Simulink and then validated experimentally under different irradiances utilizing a boost converter with a 0.05 s sampling time. The experimental results showed that the proposed strategy could be successfully implemented, with an average tracking time of 0.5 s and an average steady-state efficiency of 99.8%. Moreover, the results showed that the proposed method was superior to the standard P&O algorithm, with a 50% improvement in tracking time. In this study, a real-time test was conducted to verify the effectiveness of the proposed algorithm under different solar irradiances and temperatures.
Modular multilevel converters (MMCs) are considered very promising converters due to their modularity structure and high reliability from fault-tolerant. A fault within a submodule (SM) is one of the ...main issues in half-bridge MMCs with substantial switching devices. In this paper, an adaptive carrier based phase disposition pulse width modulation (PDPWM) technique for MMCs, which uses only one carrier having flexibility with fault-tolerant capability, is presented. The energy-based control is also used in this study to regulate the balancing of SMs during and after a fault. In order to investigate the performance of the proposed method, a laboratory single-phase MMC prototype has been built by using four SMs to generate nine-level. The single-phase MMC prototype is tested by assuming one of the SMs in the failure condition. The result revealed that the proposed method had been successfully applied to the MMC prototype to control the upper and lower arm during the failure. In addition, the reference command will correct the fault according to the adaptive carrier and the computational burden is lesser since it only uses one single carrier.
This paper presents a single-objective function optimization method for the optimal sizing and cost of a hybrid energy storage system (HESS) that integrates lithium-ion batteries (LIB) and ...supercapacitors (SC) for electric vehicle (EV) applications. The study introduces a comprehensive framework for EV modeling, incorporating simulated EV data to enhance accuracy. A key achievement involves adapting the modified–WLTC driving cycle, iteratively employed in EV simulations to accurately capture the spectrum of power and energy profiles within the designated range, ensuring adherence to BMW-i3's top speed requisites. The proposed method's validity is established by comparing optimization results using Particle Swarm Optimization (PSO) and Firefly Algorithm (FA), indicating comparable HESS sizing and cost outcomes. Notably, the PSO algorithm demonstrates superior accuracy and computational efficiency. Through PSO, the optimal LIB-SC HESS weight is determined at 160 kg with an optimal cost of $27,660, while FA yields 161 kg and $28,270, surpassing LIB-Only EV models by approximately 21 % in improved sizing. This research significantly contributes by establishing a robust EV modeling paradigm, employing simulated data for optimization, and successfully implementing PSO to determine optimal HESS parameters, advancing the field of efficient EV energy storage and promoting cost-effective, sustainable electric transportation.
•This study presents a comprehensive framework of quasi-dynamic EV modelling , using BMW-i3 simulated parameters and a modified WLTC driving cycle to optimize the sizing and cost of LIB-SC HESS.•The optimization is achieved through a single-objective function using PSO and FA algorithms, with PSO demonstrating superior accuracy and computational efficiency.•Results show that PSO achieves an optimal LIB-SC HESS weight of 160 kg at $27,660, while FA yields 161 kg at $28,270.•Furthermore, the results demonstrate a significant 21 % improvement in LIB-SC HESS sizing over LIB-only EV models, contributing to more efficient and cost-effective EV solutions.