rss_2.0Power Electronics and Drives FeedSciendo RSS Feed for Power Electronics and Drives Electronics and Drives 's Cover Winding Fault Detection of Permanent Magnet Synchronous Motors Based on the Short-Time Fourier Transform<abstract><title style='display:none'>Abstract</title><p>In modern drive systems, the high-efficient permanent magnet synchronous motors (PMSMs) have become one of the most substantial components. Nevertheless, such machines are exposed to various types of faults. Hence, on-line condition monitoring and fault diagnosis of PMSMs have become necessary. One of the most common PMSM faults is the stator winding fault. Due to the destructive character of this failure, it is necessary to use fault diagnostic methods that allow fault detection at its early stage. The article presents the results of experimental studies obtained from fast Fourier transform (FFT) and short-time Fourier transform (STFT) analyses of the stator phase current, stator phase current envelope and stator phase current space vector module. The superiority of the proposed method over the classical approach based on the stator current analysis using FFT is highlighted. The proposed solution is experimentally verified under various motor operating conditions. The application of STFT analysis discussed so far in the literature has been limited to the fault diagnosis of induction motors and the narrow range of the analysed motor operating conditions. Moreover, there are no works in the field of motor diagnostics dealing with STFT analysis for stator windings based on the stator current envelope and the stator current space vector module.</p></abstract>ARTICLE2022-06-30T00:00:00.000+00:00Analysis of the Power Supply Influence on the Universal Motor<abstract><title style='display:none'>Abstract</title><p>Due to their advantageous properties, universal motors are widely used in various applications and can be operated with both AC and DC voltage. Between main advantages of universal motors are their high starting torque, very compact design and high operating speed. In terms of the wide use of the universal motor, we want to analyze the impact of DC and AC power supply on the universal motor in this article. As part of the analysis, measurements were made of the influence of the AC/DC supply on the speed, torque, efficiency and electromagnetic radiation of the motor. At the end of the paper, the results of measurements on a universal motor with DC and AC power supply are presented.</p></abstract>ARTICLE2022-05-31T00:00:00.000+00:00Three-level Vienna Rectifier with a Brushless and Permanent Magnetless Generator for Wind Energy Conversion Systems<abstract><title style='display:none'>Abstract</title><p>This paper proposes a system design and control technique for a newly developed brushless and permanent magnetless synchronous generator-based variable-speed wind energy generation system, transferring power to a constant voltage dc grid via a three-level Vienna rectifier (VR). The recently established generator named Brushless Induction excited Synchronous Generator (BINSYG) is a wound field synchronous generator (WFSG), whose excitation is developed by controlling an Induction Machine fitted to the same machine structure and sharing the same magnetic core. A new controller is proposed that ensures the stable operation of BINSYG for a wide variation of shaft speeds. VR achieves sinusoidal input current and can control the power factor at its input, which is particularly suitable for wind energy applications. The top and bottom capacitor voltages of the VR are balanced using redundant switching combinations. The system with its proposed control algorithm is modelled in MATLAB/Simulink for a 5 kW rated BINSYG feeding power to a 750 V dc grid. The steady-state and dynamic state simulation results are presented and the controller performance is verified for a wide range of wind speeds. Further, real-time results using the OPAL-RT testbed are presented for the same system to verify the effectiveness of the overall control strategy.</p></abstract>ARTICLE2022-04-29T00:00:00.000+00:00A Hybrid Energy Storage System with Reconfigurability and Fast Equalisation<abstract><title style='display:none'>Abstract</title><p>With the rapid growth of electric vehicles (EVs) in recent years, the research on their energy storage systems (ESSs) has also shown great popularity. A traditional ESS normally has a fixed configuration and uses a single type of energy storage unit. However, this traditional design has some limitations, such as low flexibility and high requirements to unit consistency. To solve these problems, a new hybrid energy storage system is proposed in this paper. The proposed ESS hybridises multiple lithium-ion battery modules and one supercapacitor module. By controlling the states of switches inside the ESS topology, module level reconfiguration can be achieved. Further, a DC/DC converter is also included in the ESS topology, which is connected to the supercapacitor module and can be used to ensure correct ESS output voltage. Reconfiguration and active balancing algorithms are also given based on the proposed ESS topology. Situations with and without bypassing the lithium-ion battery modules are both discussed in the algorithms. The proposed hybrid ESS is finally verified with simulations. The system model is built in the Simulink/MATLAB environment. Simulation results show that the lithium-ion modules with a lower state of charge values have higher priorities to be connected in parallel. Reconfiguration actions are able to balance all lithium-ion battery modules within one Worldwide Harmonised Light-Duty Vehicle Test Cycle (WLTC) simulation cycle while maintaining ESS output voltage within a correct range. Furthermore, the proposed hybrid ESS control algorithms remain valid when one lithium-ion battery module is manually bypassed during simulation.</p></abstract>ARTICLE2022-04-29T00:00:00.000+00:00Charging and Discharging Strategies for Clustered Regional Energy Storage System<abstract><title style='display:none'>Abstract</title><p>With the massive expansion of decentralised renewable energy in electricity grid networks, the power supply system has been changed from centralised to decentralised one and from directional to bi-directional one. However, due to the regional energy structure difference in the power imbalance between electricity generation and consumption is becoming more and more serious. A grid-scale energy storage system (ESS) can be one solution to balance the local difference. In this paper, two charging/discharging strategies for the grid-scale ESS were proposed to decide when and with how much power to charge/discharge the ESS. In order to realise the two strategies, this paper focuses on the application of fuzzy logic control system. The proposed strategies aim to reduce the peak power generation, consumption and the grid fluctuation. In particular, this paper analysis the ratio between energy-capacity and rated power of ESS. The performance of the proposed strategies is evaluated from two aspects, the normalised power of ESS itself and the influence on the power grid. Simulation studies were carried out on the rule-based control systems with different energy-to-power (e2p) ratios, and the results show that the proposed charging strategy with combination of extreme situation of power imbalance and the rest capacity of ESS provides a smooth load curve for the regional power grid system while the external power exchange is reduced effectively.</p></abstract>ARTICLE2022-03-31T00:00:00.000+00:00Performance Evaluation of BB-QZSI-Based DSTATCOMUnder Dynamic Load Condition<abstract><title style='display:none'>Abstract</title><p>This paper presents the shunt compensation performance of quasi-Z-source inverter (QZSI) and back to back connected QZSIs (BB-QZSI) to address the power quality (PQ) issues in the three-phase three-wire power utility network (PUN). Generally, these PQ issues are poor voltage regulation, low power factor (PF), source current distortion, unbalanced voltage, etc. The proposed BBQZSI-based distribution static compensator (DSTATCOM) consists of two QZSIs with a common dc-link capacitor. Because the QZSI could achieve buck/boost conversion as well as DC to AC inversion in a single-stage and the back to back configuration decreases the system down time cost (if a fault occurs in one QZSI the other can continue the shunt compensation). Particularly, <italic>icos ϕ</italic> control algorithmcontrol algorithm is implemented to generate proper switching pulses for the switches of DSTATCOM. The effectiveness of the BB-QZSI is verified through simulation studies over QZSI using MATLAB/Simulink software satisfying the recommended grid code.</p></abstract>ARTICLE2022-03-31T00:00:00.000+00:00A Comprehensive Overview of the Impacting Factors on a Lithium-Ion-Battery’s Overall Efficiency<abstract><title style='display:none'>Abstract</title><p>This comprehensive overview of the impacting factors on lithium-ion-battery’s (LIB) overall efficiency presents the most relevant influencing factors on a battery’s performance. Dissected into their respective short-term and long-term influences, the working principles behind the efficiency influencing factors are presented. With a strong focus on battery characterisation, charge-profiles and battery management systems (BMSs), the authors present results of their own practical research with a detailed literary analysis, allowing a broad coverage of the complex topic. Finally, the authors present a principle model that indicates the interactions between the different involved components of the battery.</p></abstract>ARTICLE2022-02-27T00:00:00.000+00:00Quantitative Reliability Evaluation of Silicon Carbide-Based Inverters for Multiphase Electric Drives for Electric Vehicles<abstract><title style='display:none'>Abstract</title><p>Reliability of power converter in the electric drivetrain of a vehicle can be a criterion for the comparison of various converter topologies, cooling system designs and control strategies. Therefore, reliability prediction is important for the design and control of vehicles. This paper presents an approach for quantitative evaluation of the reliability of converters for multiphase motor drives for electric vehicles (EVs) after considering the driving cycle. This paper provides a good background of reliability quantification so that it is easy to extend the presented approach to other applications. The models of subsystems have been selected to have excellent computational efficiency with good accuracy which is necessary for simulating long driving cycles. A simple vehicle model is used to obtain the traction motor torque demand for various points of the driving cycle. A multiphase interior permanent magnet synchronous motor has been used for traction motor. The operating voltage and currents of the motor are found using maximum torque per ampere (MTPA) control of IPMSM. The analytical loss calculation has been used to find the losses of switching devices of the converter. A thermal model of silicon carbide (SiC) MOSFET has been used to calculate junction temperature from the losses. The model developed here gives the failure rate and mean time between failures (MTBF) of switching devices of the inverter, which can be used to determine the failure rate. The model has been used to find the transition probabilities of a Markov model which can be used to quantify the reliability of converters of multiphase electric drives.</p></abstract>ARTICLE2022-02-27T00:00:00.000+00:00Extended Feedback Linearisation Control of Non-ideal DCDC Buck Converter in Continuous-conduction Mode<abstract><title style='display:none'>Abstract</title><p>This paper presents an extended form of Feedback Linearisation Control (FBLC), which is tested in a non-ideal buck converter in Continuous-conduction Mode (CCM). The FBLC is often used in power electronics to control a non-linear system, due to its advantageous properties. The application of the error integrator shows better steady-state and transient properties, such as a decrease of inrush current. The linearised system has been controlled by the pole placement and the technique is illustrated through an example and simulated via Matlab. The results have been compared by using a classical PID controller, allowing the benefits of FBLC to be highlighted.</p></abstract>ARTICLE2022-01-31T00:00:00.000+00:00A Bidirectional Buck-Boost Converter-Based Switching Ripple Communication Strategy for Intelligent Street Lighting Systems<abstract> <title style='display:none'>Abstract</title> <p>The light-emitting diode (LED) is an essential component of intelligent street lighting (ISL) systems. An efficient ISL system can not only reduce power consumption by planning LED illuminating time but also reduce maintenance costs through a high degree of automation. In this paper, a buck-boost converter is used to realise composite transmission of power and signals for an ISL system. The power is modulated by the pulse width modulation (PWM) approach, and the switching ripple generated in the PWM process is utilised as the carrier of the signals transmitted between the remote-control centre and the slave nodes. Moreover, the proposed model involves a ‘request to send (RTS)/confirm to send (CTS)’ mechanism to avoid signal conflicts. Compared with the conventional power line communication (PLC) approach, the proposed transmission scheme has the advantages of simple circuit structure and simple system wiring. Additionally, a simulation model built in MATLAB/Simulink proves the designed transmission method has strong anti-noise ability.</p> </abstract>ARTICLE2021-12-22T00:00:00.000+00:00Sliding Mode Control of Hybrid Renewable Energy System Operating in Grid Connected and Stand-Alone Mode<abstract> <title style='display:none'>Abstract</title> <p>This paper studies innovative application of sliding mode control (SMC) for a Hybrid Renewable Energy System (HRES) in grid-connected and autonomous modes of operation. The considered HRES includes a photovoltaic (PV), wind turbine (WT) based on a Permanent Magnet Synchronous Generator (PMSG). The PV generator is coupled to the common DC bus via a DC/DC converter. The latter is controlled by an MPPT algorithm based on the Adaptive Perturbation and Observation Algorithm Method (APOAM) to search the optimum working of this source. A SMC is utilized to manage the PV voltage to achieve the Maximum Power Point (MPP) by altering the obligation duty cycle. The battery interfaced by a bidirectional buck-boost DC/DC converter can be charged or discharged depending on the production situation. On the one hand, the wind turbine conversion chain is equipped with a PMSG and a rectifier controlled to regulate the operating point of the wind turbine to its optimum value. During a Stand-Alone Mode (SAM) operation, the Voltage Source Converter (VSC) was used for controlling the output voltage in terms of amplitude and frequency delivered to the AC load. However, in Grid-Connected Mode (GCM) operation, the VSC was adapted to control the electrical parameters of the grid. To better appreciate the advantages of the proposed SMC approach, we have proposed a series of comparative tests with the conventional PI control in the operating modes GC and SA and under different scenarios. The proposed control strategy has undeniable advantages in terms of control performance and very low total harmonic distortion THD value compared with the conventional PI control. Finally, It is concluded that the proposed approach improves the quality and provides a stable operation of the HRES.</p> </abstract>ARTICLE2021-10-09T00:00:00.000+00:00A New 13-Level Switched-Capacitor Inverter with Reduced Device Count<abstract> <title style='display:none'>Abstract</title> <p>This paper proposed a new voltage-boosting 13-level switched-capacitor (SC) cost-effective inverter. The proposed topology comprises fourteen transistors, three capacitors and a single DC source to produce a 13-level staircase waveform. The capacitor voltage balancing problem is inherently solved by the series/parallel technique. Structural description, working principle, calculation of optimum values of capacitance and modulation scheme are briefly described. The comparative analyses with the existing SC multilevel inverter (MLI) in terms of voltage gain, blocking voltage, total standing voltage (TSV), component per level factor and cost function illustrate the merits of the proposed topology. Further, simulation and experimental results at different loading conditions verify the feasibility of the proposed topology.</p> </abstract>ARTICLE2021-07-05T00:00:00.000+00:00Effectiveness Analysis of Rolling Bearing Fault Detectors Based On Self-Organising Kohonen Neural Network – A Case Study of PMSM Drive<abstract> <title style='display:none'>Abstract</title> <p>Due to their many advantages, permanent magnet synchronous motors (PMSMs) are increasingly used in not only industrial drive systems but also electric and hybrid vehicle drives, aviation and other applications. Unfortunately, PMSMs are not free from damage that occurs during their operation. It is assumed that about 40% of the damage that occurs is related to rolling bearing damage. This article focuses on the use of Kohonen neural network (KNN) for rolling bearing damage detection in a PMSM drive system. The symptoms from the fast Fourier transform (FFT) and Envelope (ENV) Analysis of the mechanical vibration acceleration signal were analysed. The signal ENV was obtained by applying the Hilbert transform (HT). Two neural network functions are discussed: a detector and a classifier. The detector detected the damage and the classifier determined the type of damage to the rolling bearing (undamaged bearing, damaged rolling element, outer or inner race). The effectiveness of the analysed networks from the point of view of the applied signal processing method, map size, type of neighbourhood radius, distance function and the influence of input data normalisation are presented. The results are presented in the form of a confusion matrix, together with 2D and 3D maps of active neurons.</p> </abstract>ARTICLE2021-07-23T00:00:00.000+00:00Selected Nature-Inspired Algorithms in Function of PM Synchronous Motor Cogging Torque Minimisation<abstract> <title style='display:none'>Abstract</title> <p>Both permanent magnet brushless DC motors and permanent magnet synchronous motors have attracted wide attention and are increasingly used in industrial high-performance applications in recent years. Those motors are known for their good electrical, magnetic and performance characteristics, but there is one parameter known as cogging torque that has a negative influence on the performance characteristics of the motor. This pulsating torque is generated as a result of the interaction between the stator teeth and the permanent magnets. The minimisation of the ripple of this torque in those permanent magnet motors is of great importance and is generally achieved by a special motor design which in the design process involves a variety of many geometrical motor parameters. In this research work, a novel approach will be introduced where two different nature-inspired algorithms, such as genetic algorithm (GA) and cuckoo search (CS) algorithm are used as an optimisation tool, in which the defined equation for the maximum value of the cogging torque is applied as an objective function. Therefore, a proper mathematical presentation of the maximum value of the cogging torque for the analysed synchronous motor is developed and implemented in the research work. For a detailed analysis of the three different motor models, the initial motor and the two optimised motor models are modelled and analysed using a finite element method approach. The cogging torque is analytically and numerically calculated and the results for all the models are presented.</p> </abstract>ARTICLE2021-11-15T00:00:00.000+00:00The Effect of Different Decision-Making Methods on Multi-Objective Optimisation of Predictive Torque Control Strategy<abstract> <title style='display:none'>Abstract</title> <p>Today, a clear trend in electrification process has emerged in all areas to cope with carbon emissions. For this purpose, the widespread use of electric cars and wind energy conversion systems has increased the attention and importance of electric machines. To overcome limitations in mature control techniques, model predictive control (MPC) strategies have been proposed. Of these strategies, predictive torque control (PTC) has been well accepted in the control of electric machines. However, it suffers from the selection of weighting factors in the cost function. In this paper, the weighting factor associated with the flux error term is optimised by the non-dominated sorting genetic algorithm (NSGA-II) algorithm through torque and flux errors. The NSGA-II algorithm generates a set of optimal solutions called Pareto front solutions, and a possible solution must be selected from among the Pareto front solutions for use in the PTC strategy. Unlike the current literature, three decision-making methods are applied to the Pareto front solutions and the weighting factors selected by each method are tested under different operating conditions in terms of torque ripples, flux ripples, cur-rent harmonics and average switching frequencies. Finally, a decision-making method is recommended.</p> </abstract>ARTICLE2021-12-17T00:00:00.000+00:00MATLAB modelling of double sided photovoltaic cell module<abstract> <title style='display:none'>Abstract</title> <p>In this paper, the equatorial coordinate system is taken as the celestial coordinates, the double-sided photovoltaic module irradiance model is established by using the MATLAB simulation software, and the double-sided photovoltaic module irradiance model is combined with the photovoltaic module model (Jianhui (2001)) to form the mathematical model of the real-time generation system of double-sided photovoltaic modules. The effectiveness of the simulation model was verified by building an experimental platform, and the output characteristics of the optimal line spacing between the double-sided p-v module and the single-sided p-v module were further tested and compared.</p> </abstract>ARTICLE2021-07-05T00:00:00.000+00:00Active Damping in Series Connected Power Modules with Continuous Output Voltage<abstract> <title style='display:none'>Abstract</title> <p>This paper presents a modular and scalable power electronics concept for motor control with continuous output voltage. In contrast to multilevel concepts, modules with continuous output voltage are connected in series. The continuous output voltage of each module is obtained by using gallium nitride (GaN) high electron motility transistor (HEMT)s as switches inside the modules with a switching frequency in the range between 500 kHz and 1 MHz. Due to this high switching frequency a LC filter is integrated into the module resulting in a continuous output voltage. A main topic of the paper is the active damping of this LC output filter for each module and the analysis of the series connection of the damping behaviour. The results are illustrated with simulations and measurements.</p> </abstract>ARTICLE2021-12-30T00:00:00.000+00:00Grid-Tied Neutral Point Clamped based Centralised Photovoltaic Inverter with Improved DC Link Voltage Balancing and Harmonic Minimisation Control<abstract> <title style='display:none'>Abstract</title> <p>This paper proposes an improved space vector pulse width modulation (SVPWM) based DC link voltage balancing control of a three-phase three-level neutral point clamped (NPC) centralised inverter supplying the generated power from photo voltaic (PV) array to a three-phase utility grid. Two possible schemes have been developed based on the power conversion stage between PV array and the utility grid namely, two-stage (three-level boost converter three-phase three-level NPC inverter) and single-stage (three-phase three-level NPC inverter alone). The comparison between these two schemes has been thoroughly discussed in terms of the control strategies employed, power loss analysis and efficiency. The performance of the centralised inverter under different modes of operation has been investigated by developing the required control strategies for smooth operation. Using the proposed control strategy, the centralised inverter can be operated as a static synchronous compensator (STATCOM) during night time, if needed. The power loss incurred in the power-electronic converters has been analysed for constant and also for variable ambient temperature. The effectiveness of the centralised inverter as an active filter (AF) has also been verified when a three-phase non-linear load is considered in the system.</p> </abstract>ARTICLE2021-11-15T00:00:00.000+00:00Artificial Neural Network-Based Gain-Scheduled State Feedback Speed Controller for Synchronous Reluctance Motor<abstract> <title style='display:none'>Abstract</title> <p>This paper focuses on designing a gain-scheduled (G-S) state feedback controller (SFC) for synchronous reluctance motor (SynRM) speed control with non-linear inductance characteristics. The augmented model of the drive with additional state variables is introduced to assure precise control of selected state variables (i.e. angular speed and <italic>d</italic>-axis current). Optimal, non-constant coefficients of the controller are calculated using a linear-quadratic optimisation method. Non-constant coefficients are approximated using an artificial neural network (ANN) to assure superior accuracy and relatively low usage of resources during implementation. To the best of our knowledge, this is the first time when ANN-based gain-scheduled state feedback controller (G-S SFC) is applied for speed control of SynRM. Based on numerous simulation tests, including a comparison with a signum-based SFC, it is shown that the proposed solution assures good dynamical behaviour of SynRM drive and robustness against <italic>q</italic>-axis inductance, the moment of inertia and viscous friction fluctuations.</p> </abstract>ARTICLE2021-12-17T00:00:00.000+00:00Investigation on Control Strategies for a Single-Phase Photovoltaic Inverter Using PSCAD/EMTDC Software<abstract> <title style='display:none'>Abstract</title> <p>In the last decades, electric power produced through photovoltaic conversion has been increasing because of the need to reduce fossil fuel burning. Recently, photovoltaic systems have become more competitive and their role in the renewable energies market share is steadily gaining in importance. Improvements in the power electronics employed in the DC/AC conversion are topics of interest in the quest for more efficient and eventually reduced-cost inverters. The goal of this paper is to perform an investigation of control strategies and propose a topology for a single-phase DC/AC converter for photovoltaic arrays using the simulation software Power System Computer Aided Design/ Electromagnetic Transient Design and Control (PSCAD/EMTDC). The circuit proposed in this paper employs an isolating transformer to a grid-connected photovoltaic inverter. The control strategy proposed uses the instantaneous reactive power theory (p–q theory) and phase-locked loop (PLL). The p-q theory uses two virtual axes in the Park Transformation, which provide to the control system a good dynamic response, accuracy, and decoupling between the control and power system. Computer simulations using the electromagnetic transient software PSCAD show the efficiency of the proposed strategy for a single-phase inverter. The control strategy and topology are quite simple and easy to implement in the future using a Digital Signal Processor (DSP). The results provide insights into new power electronics solutions, which can improve the efficiency and efficacy of the current available in DC/AC converters for photovoltaic systems.</p> </abstract>ARTICLE2021-07-23T00:00:00.000+00:00en-us-1