Motor Windings Research Articles

Control Method that Reduces the High Harmonic in the Overmodulation Drive of the Dual Winding Motor during Voltage Supply Unbalance

Control Method that Reduces the High Harmonic in the Overmodulation Drive of the Dual Winding Motor during Voltage Supply Unbalance

Determining an additional diagnostic parameter for improving the accuracy of assessment of the condition of stator windings in an induction motor

This paper has proposed and substantiated the application of an additional diagnostic parameter for assessing the state of stator windings of induction motors during operation. The dependences of the values of phase shifts between phase currents and phase voltages have been obtained. These dependences showed that when an inter-turn short circuit occurs in the stator windings, the phase shifts are the same for all phases of the motor. That has made it possible to obtain the dependence of the change in phase shift on the change in the engine shaft rotation frequency. This study's result has established the dependence of the rates of change of the phase angle on the engine shaft rotation frequency for both one and two damaged phases with varying degrees of damage. When analyzing these dependences, it was found that with an increase in the number of damaged phases of the electric motor, the linear section of the dependences decreases. In addition, with an increase in the degree of phase damage, the angle of inclination of the linear sections of the characteristics decreases. That has made it possible to determine an additional parameter for diagnosing the place and degree of an inter-turn short circuit of the windings in an induction motor with a squirrel-cage rotor. The values of the additional parameter, termed by this paper's authors as a "phase criterion" can be used to assess the condition and degree of damage to the stator winding of induction motors. The values of the phase criteria for various types of damage were: when phase A is damaged by 90 %, ξ=0.634, (deg)2/(rpm)2; when phase A is damaged by 80 %, ξ=0.393, (deg)2/(rpm)2; when phase A is damaged by 80 % and phase B is damaged by 90 %, ξ=0.25, (deg)2/(rpm)2; when phase A is damaged by 80 % and phase B is damaged by 90 %, ξ=0.173, (deg)2/(rpm)2. The results of this research could be used to select an effective method for diagnosing an inter-turn short circuit in the stator winding when building a diagnostic system for induction motors as part of drives of transport equipment

ROBOT APUNG PEMBERI PAKAN IKAN KOLAM AIR TAWAR BERBASIS ARDUINO

The need for fish is increasing every year. Because it is increasing every year, fish farming must be increased in line with the use of improved fish farming technology. So that it requires an adequate technological structure and mechanization. Based on this background, the arduino-based floating robot for feeding freshwater pond fish is designed to be able to apply technology that is useful in feeding farmed fish.
 The arduino based floating robot fish feeding freshwater fish pond using Arduino Mega 2560 as its microcontroller, 4 Sharp 2Y0A21 sensors that function to detect pond walls, RTC functions as a timer so that it can feed fish according to the time set on the tool, LCD functions as the information viewer of the tool, the L298N motor driver controls the DC motor and the servo motor functions as the opening or closing of the food valve on the appliance.
 In the test, the arduino based floating robot fish feeding freshwater fish pond is able to float in water and can feed fish based on the time available on the tool. The Sharp 2Y0A21 sensor as a pool wall detector has a distance reading in the range of 1 millimeter to 10 centimeter. The robot can avoid the pool wall with a span of 3 - 7 seconds, this is influenced, among others, by surging water, wind, sensor response, and DC motors.

Operation of propeller motors composed of ship electric propulsion systems with semiconductor converters

The calculations of transient processes in ship electric propulsion systems (EPS) with semiconductor converters (SC) show that when the inverter transistors are locked, overvoltage occurs that may break through the insulation of propeller motors (PM). A feature of this overvoltage is its short duration and large value. Pulsed overvoltage of small duration and the EPS value of dozens or more kilovolts may occur in the circuits of the inverter supplying the PM winding. The main cause of overvoltage is the EPS self-induction resulting from rapid current reduction in circuits with inductances, including in motor windings, when the inverter transistors are locked. The paper presents the results of mathematical modeling of the processes arising when the inverter transistors functioning as part of the frequency converter are locked. The results of the analysis confirmed the possibility of overvoltage on the PM winding, which should be taken into account when designing the EPS and selecting equipment.

Torque Ripple Reduction for Permanent Magnet Motor using New Configuration for Concentrated Windings

This paper presents a new configuration for the concentrated windings of permanent magnet motors in order to reduce the torque ripple. There are limited choices for the concentrated windings in conventional permanent magnet motors when selecting the numbers of poles and slots, which results in winding factors for harmonics that cannot be zero and the corresponding torque ripple remains. Unlike conventional concentrated-winding motor, whose teeth are all wound with one coil, the proposed concentrated-winding motor has some teeth with multiple coils wound around. The number of turns for each coil can be optimized to reduce its winding factors for harmonics to nearly zero so that the corresponding torque ripple could be significantly reduced. Prototypes of the conventional and proposed motors were constructed, and the experimental results are compared. Simulation and experimental results confirm the torque reduction effect of the proposed concentrated-winding motor.

Design and Experimental Investigations of Shape and Attitude Carding System for the Wires of Micro Coreless Motor Winding.

The shape and attitude (S&A) of the electrode wire are important characteristics of micro coreless motor winding. The purpose of this paper is to present the design of a robotic micro-manipulation system for micro wire carding with arbitrary S&A, which can be used as the pretreatment system for wire micro-gripper systems. The system is based on the principle of flexible carding, and uses nylon, bristle, nanometer-silk and wool as materials for the brushing micro-manipulator. The trajectory of the brushing micro-manipulator is designed, and the S&A of the electrode wires are straightened through the combined motion mode of horizontal and vertical brushing micro-manipulators. The experimental results show that the material of the brushing micro-manipulator has a great impact on the carding quality. Nanometer-silk material is more suitable for horizontal brushing micro-manipulators, and wool material is more suitable for vertical brushing micro-manipulators. The geometric dimension of the brushing micro-manipulator also affects the carding quality. When the diameter is in the range of 1 mm, the carding effect of the horizontal brushing micro-manipulator with a length of 4.9–8 mm is better. The system can realize the automatic carding of flexible electrode wires with arbitrary S&A, and it will not damage the structure of wires in the process.

Improved Voltage Boundary With Model-Based Control Algorithm for Increased Torque in the Field Weakening Region of Induction Machines

At high speed, electric vehicles (EVs) have limited torque when powered by an induction machine (IM). In IM, the high-speed region is called field weakening, and the region is known for torque limitation. This article proposes a control method that increases the torque without applying discontinuous-modulation techniques, which is commonly used. A bespoke model-based voltage control method has been developed, which enables reaching the hexagonal voltage reference trajectory for the field weakening region. So far, all model-based control methods are constrained by the inscribed voltage circle, which lies within the hexagonal voltage boundary. This restriction limits the available inverter output voltage across the motor windings, which, in turn, restricts the output torque of the drive. To achieve the hexagonal voltage trajectory, this article introduces a new calculation of the d-axis current for the entire speed range in the field weakening region. This calculation is based on the hexagonal voltage boundary equations and the stator voltage vector position. This generates a new reference d-axis current that minimizes the difference between the hexagonal voltage boundary and its inscribed voltage circle. As a result, the proposed d-axis current maximizes the output torque and output power in the field weakening region. The proposed method is presented analytically. Simulation and experimentally validated results are presented to confirm its feasibility and effectiveness.

Torque ripple reduction of BLDC motor based on DC bus voltage automatic selection circuit and neutral point clamped three-level inverter control

The torque ripple of Brushless direct current motor (BLDCM) mainly depends on the commutation torque ripple, while the commutation torque ripple mainly depends on the current fluctuation during commutation. In this paper, the cause of current fluctuation during commutation is analyzed, and an automatic selection circuit based on DC bus voltage and a neutral-point-clamped (NPC) three-level inverter controller is proposed. The motor winding is guaranteed to bear half of the DC bus voltage, and the duty cycle is calculated so that the DC bus voltage at the moment of phase change is in a certain relationship with the back electromotive force (EMF) of the circuit, thus suppressing the current ripple during phase change and achieving the purpose of suppressing torque ripple during phase change.

Modeling of high frequency high voltage of waveforms on life of enamel insulation

<p>In recent years it has been observed that insulation failure in electrical motors is caused by adjustable speed drives fed by power electronic converters. These converters produce impulse waveforms having a high slew rate generated by the high switching frequency of IGBTs. This paper focuses on high switching frequency stress in low voltage electrical motors for adjustable speeds. To examine the motor winding insulation under such stress twisted-pair samples were developed from enameled wires. A single-coated polyester of enamel with a thickness of 40 microns is used for this work. High-frequencies, high voltages of Square, and Square-rising, Square-spike waveforms of 10-30 kHz are used here. The test results show that the insulation fails earlier for the Square waveform compared to the Square-spike and Square-rising waveforms. In a nutshell, there is an analysis of PD formation in the insulation system at a higher switching frequency is analyzed. Electric field distributions between twisted pairs with various air gaps of the insulation system stressed by the Square and Square-rising waveforms up to 30 kHz are modeled using COMSOL software.</p>

Temperature Estimation Using Lumped-Parameter Thermal Network With Piecewise Stator-Housing Modules for Fault-Tolerant Brake Systems in Highly Automated Driving Vehicles

With the increased interest in intelligent transportation, the need for fault-tolerant systems has also increased. In this paper, we propose a piecewise stator-housing module (PSM) and construct a lumped-parameter thermal network (LPTN) that can be used in a fault-tolerant system based on the PSM. The proposed LPTN model considers not only radial and axial heat transfer but also tangential heat transfer; therefore, even if only one of the two circuits is running on a fault-tolerant motor (dual winding motor), the coil temperature can be estimated. To verify the proposed model, three winding-type motors are tested with varying current values during normal and fault operations, and the test and analysis results are in good agreement. Additionally, the usefulness of the proposed model is demonstrated by comparing the temperatures of both the conventional and proposed LPTNs in the event of a brake system fault during braking operation in a virtual traffic jam simulation. This simulation demonstrates that temperature estimation of the motor is important for motor design because the brake operation time is dependent on the motor temperature. Furthermore, the system performance or size can be determined by accurately predicting the temperature, even in the event of a fault in the brake system, where the fault-tolerant motor is used, thus keeping the driver safe. The proposed LPTN can be used in brake systems and in other systems that utilize fault-tolerant dual winding motors.

Control System Design for 16/6/8 Double-Stator Bearingless Switched Reluctance Motor

The 16/6/8 double-stator bearingless switched reluctance motor (DSBSRM) is used as the object of study in this paper. To solve the problem of torque and levitation force ripples in this motor, a control system direct force control (DFC) and direct instantaneous torque control (DITC) based on the torque sharing function (TSF) are proposed. With the strong nonlinearity and approximation capability of radial basis function neural networks, the torque and levitation force observer are designed. The observed torque and levitation forces are used as feedback for the internal loop control, which is combined with the external loop control to make a double closed-loop control. In order to further improve the output torque and system robustness and suppress the torque ripple in steady-state process, the motor winding method is optimized and a set of switching angles is added on the basis of TSF. The simulation results verify the effectiveness and superiority of the proposed control method. It effectively suppresses speed ripple and reduces torque and levitation force fluctuations and rotor radial displacement jitter.

Adaptive backstepping control of induction motor powered by photovoltaic generator

<span>This paper is aimed at addressing the design of an effective adaptive nonlinear control of a photovoltaic (PV) water pumping system powering a submersible induction motor and a centrifugal water pump. Four objectives are achieved using an adaptive Backstepping controller. First, it is applied to ensure maximum power point tracking, and uses the latter as a reference in regulation of the rotor speed to convert the maximum electrical power into maximum mechanical power. Second, the adaptive controller is synthesized to control motor rotor flux and restrict the magnetic circuit to its linear interval. Third, it is used to online estimate the rotor time-constant and the load torque disturbance estimation. Finally, this controller is employed to limit the stator currents to protect induction motor windings. Mathematical modelling of the main elements of the system is presented. A sliding mode rotor flux estimator is employed in the output feedback control of the whole system. DC-AC converter is controlled by pulse width modulation. The feasibility, the robustness and the effectiveness of the proposed adaptive nonlinear controller are evaluated through simulations in MATLAB/Simulink environment.</span>

Steady-State Control of Fuel Cell Based on Boost Mode of a Dual Winding Motor

In recent years, a dual winding motor drive has been proposed in the field of fuel cell vehicles due to its advantages of good performance and high robustness. This new topology and its basic control method have been widely investigated. However, the previous research has not considered the current dynamic property of a fuel cell when studying the power sharing control method, but this is an important research objective for fuel cell durability. Considering the current change principle of a fuel cell, an optimal steady-state control method based on a new dual winding motor architecture boost charging is proposed to optimize the fuel cell life. In addition, in view of the current circulation problem of the fuel cell side winding in the boost mode, a Bang-Bang-PI control algorithm with a relatively constant reference value is proposed to realize the current sharing control. On this basis, the optimized control of the output current ripple of the fuel cell is realized to ensure the steady-state of the proton exchange membrane fuel cell (PEMFC). Finally, the results show that this method can control the stability of the fuel cell efficiently.

Deadbeat Predictive Current Control for Series-Winding PMSM Drive with Half-Bridge Power Module-Based Inverter

Series-winding topology (SWT) could improve the DC-link voltage utilization, as open-winding topology does. Meanwhile, it can greatly reduce the number of power devices. Firstly, for the half-bridge power modules (HBPMs)-based inverter, an N-phase series-winding motor only requires N + 1 HBPMs for driving. On the other hand, such SWT also brings new challenges to the drive system. A zero-sequence loop is introduced into the motor windings due to SWT. The generated zero-sequence current would degrade the total harmonic distortion of the phase currents and produce the additional torque ripple. Moreover, current sensors are typically integrated with the HBPMs. However, in SWT, their measured results are the leg currents of the inverter, not the phase currents of the motor, which is crucial to the motor control. Thus, this paper mainly focuses on the aforementioned problems in a three-phase series-winding permanent-magnet synchronous motor (TPSW-PMSM) drive with HBPM-based inverter. Firstly, to control the zero-sequence subspace, the voltage vector distribution of TPSW-PMSM is analyzed. In addition, two voltage vectors with zero-sequence components are selected to generate the zero-sequence voltage. Then, the phase currents are reconstructed according to the leg currents from the current sensors on HBPMs. Based on the above, the deadbeat predictive current control (DBPCC) scheme is proposed for a TPSW-PMSM drive with HBPM-based inverter. It provides the TPSW-PMSM drive with fast dynamic response and effective zero-sequence current suppression. Finally, both simulation and experimental results verify the feasibility and effectiveness of the proposed DBPCC scheme.

Machine Learning for Sensorless Temperature Estimation of a BLDC Motor.

In this article, the authors propose two models for BLDC motor winding temperature estimation using machine learning methods. For the purposes of the research, measurements were made for over 160 h of motor operation, and then, they were preprocessed. The algorithms of linear regression, ElasticNet, stochastic gradient descent regressor, support vector machines, decision trees, and AdaBoost were used for predictive modeling. The ability of the models to generalize was achieved by hyperparameter tuning with the use of cross-validation. The conducted research led to promising results of the winding temperature estimation accuracy. In the case of sensorless temperature prediction (model 1), the mean absolute percentage error MAPE was below 4.5% and the coefficient of determination R2 was above 0.909. In addition, the extension of the model with the temperature measurement on the casing (model 2) allowed reducing the error value to about 1% and increasing R2 to 0.990. The results obtained for the first proposed model show that the overheating protection of the motor can be ensured without direct temperature measurement. In addition, the introduction of a simple casing temperature measurement system allows for an estimation with accuracy suitable for compensating the motor output torque changes related to temperature.

A Review of Reduction Methods of Impact of Common-Mode Voltage on Electric Drives

In this survey paper, typical solutions that focus on the reduction in negative effects resulting from the common-mode voltage influence in AC motor drive applications are re-examined. The critical effectiveness evaluation of the considered methods is based on experimental results of tests performed in a laboratory setup with an induction machine fed by an inverter. The capacity of a common-mode voltage level reduction and voltage gradient du/dt limitation is discussed to extend motor bearings’ lifetime and increase motor windings’ safety. The characteristic features of the described solutions are compared and demonstrated using laboratory results.

DTC Switching Strategy for Open-end Winding of Induction Machines Fed by a Dual-output Indirect Matrix Converter

This paper deals with the Direct Torque Control (DTC) of Dual Indirect Matrix Converter (DIMC) feeding an open-end winding three-phase Induction Motor (IM). Indeed, the open-end winding topology allows overcoming the main problem of Common-Mode Voltage (CMV) which is responsible of presence of stresses in the motor winding in classical topologies, controlling separately the winding of the three-phases, reducing the voltage stress of the power electronics switches and to decreasing the voltage and current harmonics in each phase. The proposed Dual-output Indirect Matrix Converter generates 18 active voltage space vectors. Whereas, in the proposed algorithm presented in this paper to ensure the control of the proposed topology it is implemented only with two null vectors and six active voltage vectors for each output. It is based on same idea of the space vector pulse width modulation that is applied separately for both converters to ensure the control of their output voltages. Indeed, to ensure the required voltage at each winding the output voltage of the first matrix converter are generated normally and output voltage of the second matrix converter are generated with 180° phase shift. The obtained simulation results prove clearly the overall performance of the control of the studied drive system based on the proposed topology and its control algorithm which may be extended to other drive system application, especially in industrial application where more improved performances are required.

Criteria for Detecting Turn-To-Turn Short Circuit in Stator Windings Using Vector Analysis of Electric Motor Phase Currents

At industrial enterprises, seaports, ships, more than 80 % of all electrical engineering equipment is asynchronous motors. In a number of cases, asynchronous motors operate with a sharply variable load, in an aggressive environment; herewith they receive power from the network with deviations of the power quality indicators from the normative ones, which causes their high damageability. Turn circuits in the stator windings account for about 40 % of cases of damage to the insulation of the asynchronous motors windings. Untimely detection of the initial moment of the appearance of defects in the asynchronous motors or disruption of the operating modes of the supply network and current circuits result in emergency situations of the electrical complex, equipment downtime and damage. The article discusses the issues of diagnostics of non-full-phase modes of current circuits, mains voltages and turn circuits in the stator windings of the asynchronous motors that receiving power from the networks in conditions of voltage asymmetry. The analysis of the vector diagrams of currents, voltages and additional phase angles of the phase currents displacement arising from the asymmetry of the mains voltages and turn circuits in the stator windings has been fulfilled. The results obtained made it possible to formulate criteria for identifying the initial moment of the turn circuit and two-phase modes, both in the network and in current circuits, in stationary modes. A method for non-destructive testing of the asynchronous motors state as well as a device for its implementation has been developed. The method is based on comparing the vectors of the measured phase currents of the asynchronous motors with their calculated values. The article presents the results of modeling the change in the vectors of phase currents from the number of closed turns in the winding of the asynchronous motors. The power series of asynchronous motors was established, for which the sensitivity of detecting the initial moment of the turn-to-turn short circuit is maximum. Analytical results of the dependence of the sensitivity coefficient for turn-to-turn short circuit on the absolute increment of the modules of phase currents and the corresponding phase angles have been obtained.

Eliminating the Effect of Common-Mode Voltage on an Open-End Winding PMSM Based on Model Predictive Torque Control

In the open-end winding permanent magnet synchronous motor (OEW-PMSM) with common DC link, the common-mode voltage (CMV) will cause leakage current and zero-sequence current, which will lead to the decrease in the system life and efficiency. To solve this problem, the loop characteristics of leakage current and zero-sequence current were analyzed, and the condition for eliminating the leakage current and the zero-sequence current was deduced. Then, the CMV of the voltage vectors for the OEW-PMSM system was calculated, and the appropriate voltage vectors satisfying the conditions were selected to form the control vector sets. Combined with the model predictive torque control (MPTC), a cost function without the weight factor was proposed. The voltage vector sets were predicted by the cost function. The optimal voltage vectors were selected to control the OEW-PMSM, which can eliminate the leakage current and the zero-sequence current caused by the CMV. The effectiveness of the proposed method was verified by the simulation results.

Investigation of Turn-To-Turn Closures of Stator Windings to Improve the Diagnostics System for Induction Motors

The efficiency of using three-phase asynchronous electric motors with a squirrel-cage rotor in the transport sector depends on increasing the level of their reliability, which is possible due to the constant improvement of existing and the development of new diagnostic methods of high reliability. The most labor-consuming and difficult is the possibility of diagnostics and differentiation of turn-to-turn closures of the stator winding. The aim of the work is to establish the nature of the manifestation, influence on energy indicators and determine the diagnostic parameters of turn-to-turn closures on one and simultaneously on two phases of the stator winding of an induction motor using mathematical modeling methods. This goal was achieved through a set of studies using a refined mathematical model of an asynchronous motor, which allows you to create asymmetry of the stator windings, simulate turn-to-turn connections on one phase and simultaneously on two phases in various combinations. The most significant result of the work is the establishment of the dependences of the pulsations of the electromagnetic moment, the unbalance coefficient of the stator phase currents and the energy characteristics from the turn-to-turn short-circuits of the phases of the stator windings. The significance of the results obtained consists in establishing the dependences of the manifestation of various types of damage to the phases of the stator winding necessary for choosing a method for diagnosing turn-to-turn faults in the stator windings when building an effective diagnostic system for asynchronous motors as part of transport infrastructure drives.