Stator Winding Of Induction Motor Research Articles

Pengaruh Modifikasi Belitan Stator Motor Induksi Satu Phasa Starting Kapasitor Pada Mesin Bor Meja Terhadap Arus dan Daya listrik serta Putaran Motor

A 1-phase 4-pole starting capacitor induction motor which is used as an activator of the table drilling machine has a more complicated construction because it has a centrifugal switch which is connected in series with the capacitor for its initial start and a high rotational speed of the stator field, which is 1500 rpm. While a 3-phase 6-pole induction motor has a much simpler construction because it does not require a centrifugal switch and a capacitor for its initial start with a low rotational speed of the stator field, which is 1000 rpm. This study discusses the effect of modifying the stator winding in a 1-phase 4-pole starting capacitor induction motor on the table drilling machine into a stator winding of 3-phase 6-pole induction motor on the rotation of the rotor. Modifications are carried out on the stator winding of a 1-phase induction motor by changing the number of phases, number of poles, type of winding, wire diameter and number of windings per groove. Modifications are carried out on the windings to obtain a 3-phase 6-pole 24-groove induction motor with 200 windings per groove, a wire diameter of 0.5 mm, and a winding type of spiral double layer. In our trials without a load on the induction motor the rotor rotation decreased by 33.71% from 1498 rpm to 993 rpm, and with a load decreased by 36% from 1450 rpm to 927 rpm.

Turn To Turn Short Circuit Classification In Induction Motor Stator Windings Caused By Isolation Failure Using Neural Network (NN) Method

Almost all industries use induction motors as production aids, this is due to several reasons, namely, the resulting rotational speed is constant, the induction motor does not have a brush so that the friction loss can be reduced, and easy maintenance. In this study is to detect damage to the stator winding caused by lamination of the windings so that a short circuit occurs in one phase, which is also called a turn fault. The Fast Fourier Transform (FFT) method is used to detect currents with a load of 0%, and 100% which will later be detected for classification on the Neural Network (NN). Categorizing the level of loading and the level of damage experienced by induction motors, namely turn to turn u1, turn to turn u1 and v1, and turn to turn u1, v1 and w1. The reading of the test results conducted on the Neural Network has good prediction results because the Mean Squared Error (MSE) produced does not exceed the specified 5% erracy level.

Convolutional Neural Network-Based Stator Current Data-Driven Incipient Stator Fault Diagnosis of Inverter-Fed Induction Motor

In this paper, the idea of using a convolutional neural network (CNN) for the detection and classification of induction motor stator winding faults is presented. The diagnosis inference of the stator inter-turn short-circuits is based on raw stator current data. It offers the possibility of using the diagnostic signal direct processing, which could replace well known analytical methods. Tests were carried out for various levels of stator failures. In order to assess the sensitivity of the applied CNN-based detector to motor operating conditions, the tests were carried out for variable load torques and for different values of supply voltage frequency. Experimental tests were conducted on a specially designed setup with the 3 kW induction motor of special construction, which allowed for the physical modelling of inter-turn short-circuits in each of the three phases of the machine. The on-line tests prove the possibility of using CNN in the real-time diagnostic system with the high accuracy of incipient stator winding fault detection and classification. The impact of the developed CNN structure and training method parameters on the fault diagnosis accuracy has also been tested.

Integrated Battery Charger for EV by Using Three-Phase Induction Motor Stator Windings as Filter

This article presents an on-board charger for the electric vehicles (EVs) by integrating the drive-train components into the charging process. The stator windings of three-phase induction motor (IM) can be used as a grid interfacing inductor with the constraint that the rotor should be in the stationary position during the charging mode. This article proposes the stator winding configurations of three-phase IM split into two equal parts at zero electrical degree for the on-board integrated battery charger. The effective filtering with these two three-phase windings combination, either in series or parallel while the rotor is in a stationary position, is analyzed. The equivalent inductance provided by the stator windings for filtering is increased by generating the pulsating magnetic field (PMF) in the motor. However, it results in the unbalanced impedances in filter causing odd harmonics in the grid current. This is resolved by using a modified double synchronous reference frame control algorithm, which maintains the balanced current operation with the unity power factor at the grid interface during the charging mode. This configuration is obtained by using the existing three-phase-based drive-train components, thereby providing the saving in space and reducing the weight of EV. Experimental results for the proposed winding configurations are presented with filter losses and system efficiency.

Optimal Design of a Dual Stator Winding Induction Motor With Minimum Rate Reduction Level

Flux estimation of single winding induction machines (SWIMs) operating in a zero-speed region is challenging, since in this operation region, the voltage drop on the stator resistance value, which varies with the operating point, is not negligible. Furthermore, in this operation region, because of the interference between higher band frequencies of a dc-rejection filter with low-pass filter of the stator currents, the dc-offset of measured currents may distort the true values of the stator current. Dual stator winding induction machines (DSWIMs), which have two sets of three-phase windings with different number of pole pairs and adapt a standard squirrel cage rotor, have overcame the associated problems of SWIMs in the zero-speed region. Nevertheless, DWSIMs have lower power rating than SWIMs if they use the same stator and rotor frames. In this article, an optimal design procedure is proposed for DSWIMs, which benefits the advantages of DSWIMs and surmounts the rate reduction problem as much as possible. In this regard, the optimal flux levels ratio of winding sets and the best pole pair ratio are determined first. Afterward, the winding specifications are designated to have maximum output power, while the DSWIM advantages, especially the zero-speed region operation capability, remain valid. A DSWIM is designed, simulated in ANSYS/MAXWELL and fabricated based on the proposed method and utilizing commercially available standard stator and rotor frames. Experimental assessments verify that the DSWIM prototype has improved the rate-reduction problem up to 19% in comparison to similar proposed DSWIMs.

Transient envelope current analysis for inter-turn short-circuit detection in induction motor stator

Electrical machines are subject to faults which, depending on the type and importance of the plant, can cause material, economic and social damage. The reliability required for electric motors constantly grows due to the importance of their applications and technological advancement. One of these possible faults is an inter-turn short circuit of the stator winding. This is a very severe failure because its evolution to a worst fault is very fast. Thus, the initial detection of the inter-turn short circuit is of fundamental importance to avoid further damage to the motor. Steady-state analysis is not adequate when applied in some cases, such as unloaded machines, loads with oscillating torque and power with voltage fluctuations. The present work brings a new study of the transient current to analyze the beginning of inter-turn short circuits in the induction motor stator windings. The proposed methodology extracts the second component from the transient envelope of the motor starting current signals by principal component analysis. These components reflect the asymmetry caused by the initial short circuit and carry the desired fault information. By variance analysis it becomes possible to monitor the evolution of a short-circuit fault. Numerical and experimental signals are provided to validate the effectiveness of the novel technique.

Diagnosis of Short-circuits in Induction Motor Stator Winding Using a Modified Park Transformation

Abstract This paper deals with a novel diagnostic method for finding the stator winding short-circuit damage of induction motor drives. The proposed method is based on a new, simple idea of applying a modified, triple Park transform instead of using a computationally demanding on-line Fast Fourier Transform (FFT) analysis. The diagnostic method is based on the analysis of current and reference voltage vector components, which are the part of the Direct Field Oriented Control structure. The proposed method is verified experimentally using tests results. Further, the influence of speed, load torque and the parameters of PI regulators on the performance of the proposed diagnostic method are also discussed.

Діагностування обмоток статора асинхронного двигуна з використанням моделювання на основі годографа вектора Парка

Despite the large number of methods for monitoring the condition of the stator windings of squirrel-cage induction motors, the issue of improving and developing diagnostic equipment with a high degree of reliability that meets modern operational requirements remains unresolved. The available methods take into account only the limiting or permissible states of the winding parameters, which do not allow us to evaluate defects at an early stage of their development. An especially hard-to-diagnose damage requiring further research is the interturn short circuit in the phase of the stator winding. The paper considers a method for diagnosing interturn closure of a stator winding using mathematical modeling based on the hodograph of the Park vector. For this purpose, a mathematical model of an induction motor with established adequacy to real processes was chosen, with which the computing unit of the Park vector was used. As a result of modeling, using an example of an asynchronous motor model AIR with a power of 11 kW, the hodographs of the Park vector for a stator without defects in nominal mode were obtained; as a result of interturn closure with complex phase resistance reduced to 80% in nominal mode and in idle mode. It is established that the considered method of applying the simulation model of a squirrel-cage asynchronous motor based on the hodograph of the Park vector allows modeling defects in the stator windings, studying their effect on motor operation, and also diagnosing the degree of defects that occur in the stator. When applying the method of spectral analysis of the hodograph of the Park vector to diagnose interturn closure faults of the stator winding, it is necessary to take into account the influence on the result of the parameters of the supply network, the nature of the load, the influence of external electromagnetic fields, transient processes in the motor, etc., accounting for which requires additional research. The possibility of using method of the hodograph of the Park vector for diagnostics of windings of induction motors remotely, without stopping the operation of the motor and when used in fully automated diagnostic systems, makes this method the most promising for further development and use.

Метод ідентифікації моделей оптимального руху електромобіля з асинхронним електроприводом

There has been proposed the method of motion models identification of an electric car with a traction induction motor by horizontal road segment, optimal by the criterion of the minimum of electric losses, synthesized using a mathematical model of the magnetization curve in the form of an inverted hyperbolic sine, which with high precision binds the current in the stator winding of an induction motor with a magnetic flux created by the field of this current and therefore corresponds to the physical conditions of the actual operation of induction electric machines, and using Lagrange variational method option that leads to the field extremals in coordinates relative time, relative speed and relative electric current in the drive motor's stator winding. At the first stage of implementation of the proposed method of motion models identification of an electric car with a traction induction drive, the constants that occur in these models due to the use of two integration operations in the process of their synthesis are determined. In the second stage of implementation, we propose a direct algorithm for determining the velocity of an electric car based on its dynamics model, and in the third stage, synthesized an iterative algorithm for determining the current associated with the velocity of an electric car by the ratio obtained as a result of solving the optimization problem by the method of indefinite Lagrange multipliers. The defined conditions that are imposed on the iterative process of optimal current model identification are determined, supplied from an electric car battery through the DC to AC converter in the traction induction motor stator winding and the conditions which must satisfy the process of determining the moments of time at which the identification process of this model is carried out, on which the accuracy of determining the electric car optimal movement trajectory coordinates depends

АНАЛІЗ МЕТОДІВ ДІАГНОСТИКИ ТЕХНІЧНОГО СТАНУ ІЗОЛЯЦІЇ АСИНХРОННИХ ДВИГУНІВ

In modern conditions, improving operational efficiency and reliability of equipment is a priority that affects the final results of industrial and transport enterprises. The main condition contributing to the reduction of failures during operation is the timely diagnosis and prediction of the current state in terms of its impact on the uptime. The article highlights the current problem of monitoring the state of insulation of the stator windings of induction motors during operation. The choice of strategies and methods for diagnosing damage of various origins. The causes of damage to the insulation of electrical machines from design to operation are systematized. The analysis of existing methods for monitoring the technical condition of the insulation of the stator windings of asynchronous motors during operation is carried out. Advantages and disadvantages of the considered methods are revealed and their comparative characteristic is presented. The main types of insulation defects of asynchronous motors detected by modern methods of monitoring the technical condition are considered. A classification of insulation defects is proposed taking into account their origin and the corresponding methods for the most accurate diagnosis. The direction of development of an effective diagnostic tool for insulation of windings of induction motors is proposed.

Effects of voltage sag on the performance of induction motor based on a new transient sequence component method

Voltage sag is one of the most common power quality disturbances in industry, which causes huge inrush currents in stator windings of induction motors, and adversely impacts the motor secure operation. This paper firstly introduces a 2D Time-Stepping multi-slice finite element method (2D T-S multi-slice FEM) which is used for calculating the magnetic field distribution in induction motors under different sag events. Then the paper deduces the transient analytical expression of stator inrush current based on the classical theory of AC motors and presents a separation method for the positive, negative and zero sequence values based on instantaneous currents. With this method, the paper studies the influences of voltage sag amplitude, phase-angle jump and initial phase angle on the stator positive- and negative-sequence peak currents of 5.5 kW and 55 kW induction motors. This paper further proposes a motor protection method under voltage sag condition with the stator negative-sequence peak currents as the protection threshold, so that the protection false trip can be avoided effectively. Finally, the calculation and analysis results are validated by the comparison of calculated and measured stator peak value of the 5.5 kW induction motor.

FEM based electromagnetic signature analysis of winding inter-turn short-circuit fault in inverter fed induction motor

The intent of this paper is to analyze the electromagnetic signature of stator winding inter-turn short-circuit fault in a closed loop speed controlled Induction Motor (IM) employing Finite Element Method. Stator winding short-circuit nearly covers 21% of faults in IM. Diagnosing the inter-turn fault at an incipient stage is one of the challenging task in the area of fault detection of IM to prevent crucial damages in industrial applications. Also detecting the faults in inverter fed IM under variable speed applications under varying load is one of the major issues in industrial drives. As the signatures of electromagnetic field contains the entire data in association with the location of rotor, stator and mechanical parts of the motor, a regular monitoring of fields in the airgap can be used to diagnose the inter-turn fault in the stator winding of IM. In this direction, an IM is modeled with several inter-turn fault severities like 30 turns, 15 turns, 5 turns & 1 turn short using ANSYS Maxwell FEA tool and coupled with ANSYS Simplorer for loading arrangements. The PWM inverter with closed loop speed controlled strategy is implemented in Matlab Simulink and co-simulated with ANSYS Simplorer to integrate all the components in one common simulation platform environment for accurate design & analysis for realistic simulation. Several electromagnetic variables like flux density, flux lines and airgap flux density distribution over the machine are analyzed. The spatial FFT spectrum of radial component of flux density in the airgap contains the information related to the diagnosis of inter-turn fault at the incipient stage.

ПОВРЕЖДЕНИЯ ОБМОТОК СТАТОРА АСИНХРОННЫХ ДВИГАТЕЛЕЙ И ИХ ДИАГНОСТИКА

ПОВРЕЖДЕНИЯ ОБМОТОК СТАТОРА АСИНХРОННЫХ ДВИГАТЕЛЕЙ И ИХ ДИАГНОСТИКА

Controlling the speed and flux of a dual stator winding induction motor using an emotional intelligent controller and integration algorithm

The appropriate efficiency of a dual stator winding squirrel-cage induction motor (DSWIM) is obtained when the ratio of two frequencies feeding the machine is equal to the ratio of the number of poles. In the vector control method, the estimation of flux at low speed is difficult. To solve this problem, researchers have benefited from the free capacity of the two windings of the stator. This makes the motor deviate from its standard operating mode at low speed. The main purpose of the present study is to reduce the power losses of the inverter units in the sensorless DSWIM drive using the proposed control scheme at low speed. In this control scheme, the speed is estimated based on the modified intelligent model reference adaptive system (MIMRAS) without estimating the stator resistance at low speed. The proposed methods were simulated in MATLAB/Simulink software, and the results of simulation confirmed the assumptions.

Modeling of single and bi-objective brain emotional intelligent controllers for improved performance of the dual stator winding induction motor drive at low speeds

Modeling of single and bi-objective brain emotional intelligent controllers for improved performance of the dual stator winding induction motor drive at low speeds

Discontinuous decoupled SVPWM schemes for a four‐level open‐end winding induction motor drive with waveform symmetries

A four-level open-end winding induction motor drive (OEWIMD) is realised by feeding the open stator windings of a three-phase induction motor from either end with two-level voltage source inverters (VSIs). These VSIs are operated with unequal DC-link voltages, which are in the ratio of 2:1. This circuit configuration has the disadvantage of overcharging the DC-link capacitor of the inverter operated with the lower input voltage. Decoupled space vector pulse-width modulation (DSVPWM) schemes, which were suggested in the previous literature to circumvent this problem, result in higher switching power loss in the dual-inverter topology. It is known that the discontinuous pulse-width modulation (PWM) schemes reduce the switching power loss. However, lack of structural symmetry of the power circuit renders it unwieldy to devise these PWM schemes. This study explores the applicability of discontinuous decoupled SVPWM (DDPWM) techniques for the four-level OEWIMD, without compromising on the waveform symmetries. With the aid of an improvised loss model, it is shown that these PWM schemes achieve the reduction of the overall loss of the four-level OEWIMD compared to the DSVPWM schemes. It has also been observed that one of the proposed DDPWM schemes result in reduced dv⁄dt in the motor phase voltages.

Decoupled centric and non-centric PWM techniques for open-end winding induction motor drive

This article proposes the space vector based decoupled centric and non-centric PWM techniques for open-end winding induction motor drive. To make the proposed configuration, 2-coventional inverters are fed on either side of open-circuited stator winding of induction motor. Therefore three level output is achieved. To obtain the control pulses for inverters in the proposed configuration reference sinusoids are used. All the proposed PWM techniques use the equal switching frequency. To obtain the validation for the proposed work various theoretical and simulation analysis is carried out using v/f control and the corresponding output voltage is verified experimentally using 1HP asynchronous motor.

Modeling of three-phase electric motor operation by the MATLAB system with deteriorated power quality in the 0.38 kV distribution networks

One of the main operation modes that characterizes power quality in distribution networks is asymmetry of three-phase voltage system. Operation of an induction motor (IM) with disturbed voltage symmetry in the supply network can not be considered as a rated one. The system of voltages applied to the stator winding of IM under these conditions contains positive- and negative-sequence components. This worsens the performance characteristics of IM essentially. In order to balance the 0.38 kV network operation and enhance the efficiency of the three-phase electric motor operation it is suggested to use a special balancing unit (BU) that minimizes the negative-sequence components of current and voltage. The operation modes of the obtained system “supply source – induction motor – balancing unit” are simulated within the MATLAB software package of applied programs, which allows one to assess the impact of low quality of power on the operating characteristics of the electric motor and the efficiency of the balancing unit to increase the “durability” of the motor under the asymmetrical power consumption.

Induction Motor Stator Fault Diagnosis by Rotor Slots Harmonics Tracking Using Prony Improved Approach

The short-circuit fault diagnosis is essential in order to avoid irreversible damages that could affect the stator circuit of the induction motor. For this purpose, this paper addresses a new approach based on Prony's high resolution spectral analysis method to avoid the drawbacks of the well-known method based on the power spectral density estimation by Periodogram technique. This new approach, called Root-Prony, allows a better frequency resolution even on a very short acquisition time as well as a better detection even on very small magnitudes. Moreover, and in order to reduce the computation time of this approach, this paper proposes to analyze only the band around the first rotor slot frequencies. The choice of this band allows avoiding any confusion with the frequency signatures of external phenomena which appear most often in very low frequencies. The experimental results obtained show the efficiency and the reliability of this new approach in tracking the induction motor stator winding degradation.

Reliable Detection of Rotor Faults in IM Using Frequency Tracking and Zero Sequence Voltage

The AC Alternating Current Induction Motor (IM) is the most commonly used AC motor in industrial applications because of its simplicity, robust construction, and relatively low manufacturing costs. To avoid expensive repairs in IM, early faults detection is needed. In this context, this paper presents a novel approach used to detect rotor asymmetries in induction motors. The Zero Sequence Voltage (ZSV) defined as the potential difference between the null point of the supply voltage system and the neutral of the star connection of IM stator winding is measured and employed for tracking the amplitude of the most sensitive harmonics in the spectrum of ZSV. This detection leads to make a criterion to take a decision about the state of the machine without a Prior knowledge. Simulation and experimental results obtained from real tests are presented to validate the study.