rss_2.0Power Electronics and Drives FeedSciendo RSS Feed for Power Electronics and Drives Electronics and Drives Feed of BLDC Motor Drive with Single Hall Sensor Considering Angle Compensation<abstract> <title style='display:none'>Abstract</title> <p>The traditional brushless DC motor uses three position sensors to realise six-step reversing control of the motor. The application of three position sensors increases the cost, whereas the sensorless control method represented by the back electromotive force method has the problem of low control accuracy. Therefore, the present research proposes the method of six-step motor reversing control by using single sensor, corrects the motor running state by using the peak–peak difference of phase current in the control process, and resultantly achieves a good control effect. The experimental results prove the control and correction method.</p> </abstract>ARTICLEtrue Network-Based Optimisation of Sinusoidal PWM Controller for VSI-Driven BLDC Motor<abstract> <title style='display:none'>Abstract</title> <p>Although increasing the number of switches increases the switch losses, most designed controllers focus on controlling an inverter circuit with more than six switches. The paper aims to address this issue that arises in implementation of the voltage source inverter (VSI) for brushless DC (BLDC) motors. It optimises the sinusoidal pulse width modulation (PWM) controller, minimising total harmonic distortion (THD) while keeping the VSI’s circuit at six switches to avoid increased switching losses. This was achieved by applying an artificial neural network (ANN) to generate a signal, which combines with the already existing reference and carrier signals. The addition of the new signal to the existing signals contributed to generating more pulses compared with the conventional sinusoidal PWM. Simulink was used to design the system and analyse its performance with the conventional and neutral point clamped (NPC) VSI systems. Results indicated that the proposed system performs better when controlled with an LCC filter. Compared with the control experiments, its output waveform has the lowest THD value, which is 6.04%. The switching losses of all the systems were also computed. Results from the computation indicated that the proposed system is capable of reducing the switching losses by 0.6 kW compared with the NPC VSI brushless DC motor (BLDCM) system. BLDCM speed was tested across various conditions; the results are reported in Section 5.</p> </abstract>ARTICLEtrue Optimal Control for a Gas Compressor Actuated by a Five-Phase Induction Motor<abstract> <title style='display:none'>Abstract</title> <p>The article proposes a nonlinear optimal control method for the dynamic model of a gas centrifugal compressor being actuated by a five-phase induction motor (5-phase IM). To achieve high torque and high power in the functioning of gas compressors, 5-phase IM appear to be advantageous in comparison to three-phase synchronous or asynchronous electric machines. The dynamic model of the integrated compression system, which comprises the gas compressor and the 5-phase IM, is first written in a nonlinear and multivariable state-space form. It is proven that the electrically driven gas-compression system is differentially flat. Next, this system is approximately linearised around a temporary operating point that is recomputed at each sampling interval. The linearisation is based on first-order Taylor series expansion and uses the computation of the Jacobian matrices of the state-space model of the integrated system. For the linearised state-space description of the compressor and 5-phase IM, a stabilising optimal (H-infinity) feedback controller is designed. This controller achieves a solution to the nonlinear optimal control problem of the compressor and 5-phase IM system under model uncertainty and external perturbations. The feedback gains of the controller are computed by solving an algebraic Riccati equation at each iteration of the control method. Lyapunov analysis is used to demonstrate global stability for the control loop. Additionally, the H-infinity Kalman filter is used as a robust state estimator, which allows for implementing sensorless control for the gas compression system.</p> </abstract>ARTICLEtrue Current Sensor Fault-Tolerant Control of Induction Motor Drive with Online Neural Network-Based Rotor and Stator Resistance Estimation<abstract> <title style='display:none'>Abstract</title> <p>This article presents an active current sensor (CS) fault-tolerant control (FTC) strategy for induction motor (IM) drive with adaptation of rotor and stator resistances. The stator current estimator with online adaptation of resistance parameters was applied for the reconstruction of missing current signals. A model reference adaptive system (MRAS), based on a neural network (NN), was used to estimate the rotor resistance. Additionally, stator resistance estimation was applied based on ratio index. The use of such a solution allowed for a significant increase in the quality of stator current reconstruction, which is particularly important for the design of CS fault detection (FD) and compensation algorithms. A wide range of simulation studies have been carried out for different operating conditions of the IM drive. The results showed that applying rotor and stator resistance estimation can improve the quality of stator current estimation by up to approximately 95% under rated operating point. The study was carried out for nominal and low speeds, with two, one, and without healthy CS.</p> </abstract>ARTICLEtrue of the Drive of the Electric Vehicle with Six-Phase Induction Motor<abstract> <title style='display:none'>Abstract</title> <p>The article presents the analysis of the drive system of the electric vehicle with a six-phase induction motor. The mathematical models of the six-phase induction motor and model reference adaptive system (MRAS<sup>F</sup>) estimator are presented, and the description of the voltage source inverter, space vector modulator and bidirectional buck–boost converter is shown. The direct field-oriented control (DFOC) system and the direct torque control with space vector modulation (DTC-SVM) system are analysed. Results of simulation studies of these control methods and comparative analysis are shown. The DTC-SVM method is selected as the method with the best properties, and a full model of the electric vehicle drive system is built using this method. The detailed description of the drive system of the electric vehicle with a six-phase induction motor and DTC-SVM control system and the results of simulation tests for this drive system are presented. The aim of the authors and an element of novelty is to develop and test a drive system for an electric vehicle with a six-phase induction motor, adaptive speed estimator and extensive space vector modulator.</p> </abstract>ARTICLEtrue FEA-Based Design and Performance Analysis for a Single-Phase PM Brushless DC Motor<abstract> <title style='display:none'>Abstract</title> <p>In the article, an approach to design a novel single-phase permanent magnet (PM) brushless DC (BLDC) motor, based on multi-step FEA numerical prototyping, is presented. The designing procedure is carried out by using a series of 2D finite element simulations, until the design for a best performing PM BLDC motor is obtained. The proposed novel motor topology is developed using a generic motor, and through several steps, asymmetrical stator poles are devised, where one pair is particularly shaped. Permanent magnets are also simultaneously shaped. The aim of this research study is to improve performance characteristics of the motor by more efficient utilisation of active materials during the manufacture of rotor poles and stator cores. The magnetic field distribution in the motor cross-section, along with several other relevant electromagnetic and electromechanical characteristics, are computed, presented in figures and charts and analysed. The cogging torque and static torque waveforms, as well as the distribution of flux density and the air-gap flux, flux linkage and the induced back-emf, are in the focus of the presented research study. The results show that the novel design topology reveals featured operating characteristics, providing a smooth overall performance of the PM BLDC motor.</p> </abstract>ARTICLEtrue of Output Voltage Ripple in Phase-Staggered Series-Connected Two-Quadrant Power Converters for Electromagnets in Particle Accelerators<abstract> <title style='display:none'>Abstract</title> <p>In booster synchrotron, fast-ramped power converters (FRPCs) are used for ramping up the magnetic field of electromagnets connected in series, at a fast rate, typically 1,000s of ampere per second. In large accelerators, the number of electromagnets is large. Therefore, during ramping, the peak value of driving voltage becomes prohibitively large considering the insulation requirement of the magnets and cables. The power converter is therefore developed by connecting a suitable number of smaller voltage rated modules in series. The series-connected modules are operated in phase-staggered mode to reduce the output voltage ripple or to reduce the filtering requirement to meet the prescribed ripple voltage. Since the filter component values predominantly decide the dynamic response, the achievable small-signal bandwidth of the control loop and hence the achievable tracking accuracy of the ramping output current are essentially governed by the filter components. To optimise the filter design, quantification of overall ripple voltage is crucial, that too under the most practical conditions considering non-ideal conditions. In this paper, estimation of overall ripple voltage is performed for series-connected two-quadrant power converters (TQPCs) operating in phase-staggering mode for ideal and non-ideal conditions. Simulation and experimental verification results are shown to be in good agreement with the analytical results.</p> </abstract>ARTICLEtrue Novel Feedback Linearisation Control of Flyback Converter<abstract> <title style='display:none'>Abstract</title> <p>This paper presents a novel approach for feedback linearisation in a continuous conduction mode (CCM) of the flyback converter. Due to the unstable zero dynamics, a flyback converter has highly non-linear behaviour. Flyback converters mostly use the indirect (current) control mechanism. In contrast, this paper shows a direct control of the output voltage of a flyback converter with feedback linearisation (a non-linear control method). In the designed controller, an error integrator is applied to improve the dynamic and steady-state behaviour of the controller. To design the feedback linearisation method, the state-space averaged model is determined. The converter and the proposed control are tested in a MatLab/Simulink environment, and the results are compared with other optimal controller methods. The results provide feedback about the efficiency and practical implementation of the proposed method.</p> </abstract>ARTICLEtrue Shift for Compensation of Dead-time Distortion in Pulse-width-modulated Voltage Source Inverter<abstract> <title style='display:none'>Abstract</title> <p>Accurate current polarity detection is a major issue for successful compensation of dead-time distortion in pulse-width-modulated (PWM) voltage source inverter. The present study is concerned with the concept of shift in current-zero-crossing due to dead-time distortion compensation that results in error in current polarity detection and thus causes a problem with regard to the successful continuation of compensation. The phenomenon is analysed in detail, along with its dependence on different factors. The proposed concept is validated in digital simulation and also through experimental verification. The study also recommends the possible correction to be incorporated in view of such zero-crossing shift for achieving proper compensation, especially in case of current-sensor-less compensation techniques.</p> </abstract>ARTICLEtrue Elimination for a Buck Converter Using the Multi-Objective Grey Wolf Optimiser<abstract> <title style='display:none'>Abstract</title> <p>A wide variety of nonlinear phenomena, such as bifurcation and chaos, have been observed in power electronics converters. Much research has been conducted on these behaviours in different converter topologies. The buck converter is known to exhibit chaotic behaviour in a wide parameter range, giving rise to unstable behaviours depending on the circuit parameters values. This paper investigates this bifurcation behaviour by varying the parameters of a voltage PI (Proportional Integral) controlled buck converter operating in continuous conduction mode, using a continuous-time model and constant frequency control signal. Furthermore, a novel and improved version of the PI compensation technique, designed using the multi-objective grey wolf optimiser (MOGWO), is proposed to stabilise the buck converter from chaotic state to periodic orbit.</p> </abstract>ARTICLEtrue of Mechanical Loads in Electric Drives – An Overview of Methods<abstract> <title style='display:none'>Abstract</title> <p>The aim of the presented paper is to introduce the reader to hardware-in-the-loop (HIL) simulation in electric drives, the motivation for its usage and its benefits. Basic information about HIL simulation in general and the connection to electric drives is followed by an explanation of the main principle of the dynamic emulation of mechanical loads for electric drives, which is a special case of HIL simulation. Next, the description of the three main methods of load emulation and their mathematical background are presented in the order of historical appearance: the emulation with compensator and tracking controller, the emulation based on non-linear control and the emulation with feed-forward compensation with the use of inverse dynamics.</p> </abstract>ARTICLEtrue FPGA-Based Controller for Three Phase Shunt Active Power Filter<abstract> <title style='display:none'>Abstract</title> <p>In this paper, a three-phase shunt active power filter (SAPF) controller with a fully digital implementation is presented. The main goal of this contribution is to implement a digital direct power control (DDPC) algorithm without phase-locked-loop (PLL) for SAPF. This algorithm is intended for power quality improvement and current harmonic elimination. The controller introduced in this paper is cost-effective, has a fast-dynamic response, and has a simple hardware implementation. In order to comply with the above specifications, a dedicated controller has been conceived and fully implemented within a field-programmable gate array (FPGA) device. This FPGA-based controller integrates the whole signal-processing functions needed to drive the SAPF, as well as an original method for sector identification. The intended controller provides the desired power references to select the optimal switching sequences. The switching orders follow the grid reference to drive the voltage source inverter (VSI), so the SAPF achieves good performances while ensuring balanced overall supply currents, unity power factor, and reduced harmonic load currents. The proposed digital implementation achieves a valuable compromise between fast dynamic response, minimum execution time, and reduced FPGA resources, through a simple hardware design implementation. The entire system is developed and simulated using VHDL and VHDL-AMS languages.</p> </abstract>ARTICLEtrue of SVC-Coupled Hybrid DSTATCOM using JLMS Algorithm for Enhancement of Power Quality<abstract> <title style='display:none'>Abstract</title> <p>This research study explains the design and performance of a Static VAR Compensator (SVC) coupled Hybrid Distribution Static Compensator (DSTATCOM) for low voltage power distribution system (PDS). A comparative analysisis done between Voltage Source Inverter (VSI)-based DSTATCOM and SVC Hybrid DSTATCOM using Jordan Least Mean Square (JLMS) algorithm to alleviate the shunt-related power quality (PQ) glitches. The specific design is obtained as compared to the existing neural network toolbox algorithm to improve the estimation speed and accuracy. The main objective is to extract the tuned weighted values of fundamental active and reactive power components of distorted load currents for the switching signal generation using an adaptive JLMS algorithm.Several functions of DSTATCOM and hybrid DSTATCOM using this JLMS controller are showcased for harmonics curtailment, power factor (p.f.) improvement, load balancing, voltage regulation, etc. Simulation results on an SVC Hybrid DSTATCOM have shown an acceptable level of performance under unbalanced loading situations. Finally, some comparative results are provided to validate the feasibility and effectiveness of the suggested topology.</p> </abstract>ARTICLEtrue of the Stator Current Prediction Capabilities in Induction Motor Drive Using the LSTM Network<abstract> <title style='display:none'>Abstract</title> <p>In modern areas of knowledge related to electric drive automation, there is often a need to predict the state variables of the drive system state variables, such as phase current and voltage, electromagnetic torque, stator and rotor flux, and others. This need arises mainly from the use of predictive control algorithms but also from the need to monitor the state of the drive to diagnose possible faults that have not yet occurred but may occur in the future. This paper presents a method for predicting stator phase current signals using a network composed of long-short-term memory units, allowing the simultaneous prediction of two signals. The developed network was trained on a set of current signals generated by software. Its operation was verified by simulation tests in a direct rotor flux-oriented control (DRFOC) structure for an induction motor drive in the Matlab/Simulink environment. An important property of this method is the possibility of obtaining a filtering action on the output of the network, whose intensity can be controlled by varying the sampling frequency of the training signals.</p> </abstract>ARTICLEtrue Estimation MRAS and Identification of Stator Winding Phase Fault Detection of the PMSG in Wind Energy Based on the Sliding Mode Control<abstract> <title style='display:none'>Abstract</title> <p>This paper proposes a method for the diagnosis of stator inter-turn short-circuit fault for permanent magnet synchronous generators (PMSG). Inter-turn short-circuit currents are among the most critical in PMSG. For safety considerations, a fast detection is required when a fault occurs. This approach uses the parameter estimation of the per-phase stator resistance in closed-loop control of variable speed of wind energy conversion system (WECS). In the presence of an incipient short-circuit fault, the estimation of the resistance of the stator in the d-q reference frame does not make it possible to give the exact information. To solve this problem, a novel fault diagnosis scheme is proposed using parameter estimation of the per-phase stator resistance. The per-phase stator resistance of PMSG is estimated using the MRAS algorithm technique in real time. Based on a faulty PMSG model expressed in Park’s reference frame, the number of short-circuited turns is estimated using MRAS. Fault diagnosis is on line detected by analysing the estimated stator resistance of each phase according to the fault condition. The proposed fault diagnosis scheme is implemented without any extra devices. Moreover, the information on the estimated parameters can be used to improve the control performance. The simulation results demonstrate that the proposed method can estimate the faulty phase.</p> </abstract>ARTICLEtrue Vibrations Analysis in Direct Drive Using CWT with Complex Morlet Wavelet<abstract> <title style='display:none'>Abstract</title> <p>Modern industrial process and household equipment more often use direct drives. According to European policy, Industry 4.0 and new Industry 5.0 need to undertake the effort required to ensure a sustainable, human-centric, and resilient European industry. One of the main problems of rotating machines is mechanical vibrations that can limit the lifetime of the final product or the machine in which they are applied. Therefore, analysis of vibration in electrical drives is crucial for appropriate maintenance of the machine. The present article undertakes an analysis of vibration measured at the laboratory stand with multiple dominant frequencies in the range 50–500 Hz. The fast Fourier transform (FFT) gives information about the frequency component without its time localisation. While the solution made available by the short-time Fourier transform (STFT) is able to overcome the problem of FFT, it still has limitations, particularly in terms of there being a lacuna in time and frequency localisation; accordingly, the need is felt for other methods that can give a good localisation in time and frequency. In the article, the continuous wavelet transform (CWT) was investigated, which requires selection of the wavelet function (kernel of transformation). The complex Morlet wavelet was selected with description of its central frequency and bandwidth. CWT and STFT time-frequency localisation capabilities were compared to investigate data registered from the direct-drive laboratory stand. CWT gives better frequency localisation than STFT even for the same frequency resolution. Vibration frequencies with near-locations were separated in CWT and STFT joined them into one wide pick. To ensure a good extraction of frequency features in electric drive systems, the author, based on analysing the results of the present study, recommends that CWT with complex Morlet wavelet be used instead of STFT.</p> </abstract>ARTICLEtrue Model Predictive Control of a Single-Phase Multilevel T-type Converter for a Photovoltaic Grid Connected System under Failure Conditions<abstract> <title style='display:none'>Abstract</title> <p>The article presents two contributions: the first is an optimised control structure for photovoltaic grid connected systems (PVGCSs). The power chain is composed of two cascaded power converters, namely, a boost converter and a five-level T-type multilevel converter. Traditionally, each power converter is controlled by a separate mode control (SMC) from the other, which is computationally intensive since each converter requires its own control system, which is not practical. The suggested control, called integrated finite set model predictive control (IFS-MPC), allows controlling cascaded converters at the same time in one stage, instead of controlling them separately. Consequently, the overall implementation system is widely reduced. The second contribution of the article is a modified IFS-MPC called modified integrated finite set-model predictive control (M-IFS-MPC), which ensures the correct functioning of the grid-tied PV system under certain faults in converter components. Indeed, when one of the DC-link capacitors fails or when one of the auxiliary switches breaks down, by selecting an appropriate choice of the DC-link capacitors’ voltage reference, the proposed design allows a normal operation without intervention on the power circuit.</p> </abstract>ARTICLEtrue Comparative Study of Grid-Following and Grid-Forming Control Schemes in Power Electronic-Based Power Systems<abstract> <title style='display:none'>Abstract</title> <p>Along with de-carbonisation, the penetration of power electronic converters has increased, and the power system has become a power electronic-based power system. In such a situation, the stability of the power system faces great challenges. In the event of a large disturbance, the power grid will lack the ability to maintain a stable voltage and frequency. In order to improve the stability of the power grid, the traditional grid-following (GFL) control is needed to be converted to the grid-forming (GFM) control. This paper analyses the control schemes of the GFL and GFM converters by investigating their state-space models, and the eigenvalue trajectories of both control schemes are shown to analyse the stability of the systems. Moreover, a case study is exemplified to compare the performance of the two control strategies while responding to frequency disturbances. Finally, a time-domain simulation model of a 15 kW grid-connected converter is built in Matlab/Simulink to benchmark the performance of the GFL and GFM converters under different working conditions. The result reveals that the GFL converter may encounter some instabilities when applied in power electronic-based systems, while the GFM converter is more suitable for the weak power grid.</p> </abstract>ARTICLEtrue Time Reduction with 2.5D FEM Analysis for Axial Flux Machines<abstract> <title style='display:none'>Abstract</title> <p>In this paper, an approach for a two-and-half-dimensional (2.5D) finite element method (FEM)-based analysis, or quasi-three-dimensional (3D) FEM analysis, of an axial flux machine is discussed. By cutting the 3D model laterally and thereby creating cylindrical surface cuts, the 3D model can be split into several cylindrical surfaces. Transforming those cylindrical cuts into planes leads to a layer-based two-dimensional (2D) model with different radii for each layer. By integrating over all lateral surface cuts, the results for the entire axial flux machine can be determined. In comparison to the simulation of a full 3D FEM model, the simulation of the proposed 2.5D model is much faster. To validate the approach, the two main types of axial flux machines are simulated with both 3D-FEM-based model and 2.5D-FEM-based approach, and the results are presented in this paper.</p> </abstract>ARTICLEtrue DSTATCOM for PQ Improvement: A Deep-Learning Approach<abstract> <title style='display:none'>Abstract</title> <p>With the rapid advancement of the technology, deep learning supported voltage source converter (VSC)-based distributed static compensator (DSTATCOM) for power quality (PQ) improvement has attracted significant interest due to its high accuracy. In this paper, six subnets are structured for the proposed deep learning approach (DL-Approach) algorithm by using its own mathematical equations. Three subnets for active and the other three for reactive weight components are used to extract the fundamental component of the load current. These updated weights are utilised for the generation of the reference source currents for VSC. Hysteresis current controllers (HCCs) are employed in each phase in which generated switching signal patterns need to be carried out from both predicted reference source current and actual source current. As a result, the proposed technique achieves better dynamic performance, less computation burden and better estimation speed. Consequently, the results were obtained for different loading conditions using MATLAB/Simulink software. Finally, the feasibility was effective as per the benchmark of IEEE guidelines in response to harmonics curtailment, power factor (p.f) improvement, load balancing and voltage regulation.</p> </abstract>ARTICLEtrue