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Modern day manufacturing practices are focusing on maximizing production while actively pursuing ways to mitigate potential failures in their products. With rotating machinery, part of this pursuit requires qualification checkpoints during manufacturing processes. For motor stators, it is essential to perform in-process insulation testing to ensure the dielectric integrity of the system is maintained...
This paper examines the modeling of the propulsion system of a large electric vehicle in the emtp-type program PSCAD/EMTDC. Challenges encountered during the modeling process are presented and discussed, and drawbacks of the model are presented as well. Results with the full propulsion system functioning and responding to torque commands from an indirect field oriented controller. The results presented...
Nowadays doubly fed induction generators (DFIG) are the most popular generator used in wind turbine plants because of their cost effective partly rated power converter and variable speeds. The main drawback of DFIG is their sensitivity to gird perturbation especially voltage dips since the stator is directly connected to the grid. Rapidly increasing contribution of wind energy in power generation...
This paper presents some topological solutions for the connection to the grid of a wind turbine using a DFIG, in order to increase the reliability of the gearbox. The so called crowbar system is studied to demonstrate its contribution to the gearbox mechanical stress. Analytical models are used to present the advantages of inserting a series voltage to the DFIG stator during voltage dips in order...
This paper develops a finite element model for modeling of the cage induction motors with inter-turn short circuits in the machine stator slots. The machine is modeled in magneto-evolutionary. Inter-turn fault within the stator slot was studied. A stator current spectrum of both healthy and faulty machines is simulated. New frequency components of the line current spectra can appear as a consequence...
Performance of a 3-phase PM transverse flux generator with internal stator is analyzed. Magnetic flux density distribution, induced voltage, output power, and cogging torque are determined using 3-D FEM. Application of generator version with internal stator allows to increase a power to volume ratio as well as to compose easily the wind turbine-generator aggregate which is proposed.
High availability is a major concern in naval drive applications. In consequence, multiphase machines, e.g. IM with double-star stator windings, are used. To guarantee the high availability, comprehensive scenario-based analyses of the machine-control behaviour in case of faults have to be performed. Asymmetrical faults - which are a practical issue - are not featured by any simplified single-phase...
Double-loop control systems of brushless DC motor (BLDCM) yield a combination of desired characteristics including simplified control structure, high speed accuracy, wide operating speed range and fast dynamic response. The current loop is very important for system performance. Its linearity is influenced by the accuracy of feedback current. The cost of detecting currents in three windings is higher,...
Fault occurrence in electrical machines is avoidable but, quick fault detection can increase system reliability. According to studies of electrical power research institute (EPRI), most of the occurred faults in electrical motors are created in bushes (41%) and winding (37%). According to high probability of winding fault occurrence in motor, its fault diagnosis is so important. Source of this fault...
A fault-tolerant technique valid for both open-loop and vector-control motor-drive systems is introduced in this paper. The technique is merely presented for AC motors with Delta-connected circuits in their stator windings. Hence, it enables the operation of the three phase motor upon a failure in one of its phases without the need of a special fault detection algorithm. This technique is to significantly...
The multi-machines system is intensively used in several industrial applications. When a fault occurred in one machine, it is very difficult to identify which one is affected by the fault. Therefore, this paper presents an efficient method to locate the faulty machine in dual induction motors supplied by a single inverter. The treated system is composed by two induction motors fed by a PWM voltage...
In this paper, a measurement of the super transient reactance considering the stator winding resistor is put forward, and the steady shortcut current and voltage of two phases in the stator are analyzed as well as relative formula. Based on the data collection system, the super transient reactance in the 3-phase synchronous generator can be obtained. Then correspondent experiment is conducted to testify...
Through the analysis of the electromagnetic properties for the rotor coil of turbine generator, we obtained the main magnetic field variation characteristics for the rotor winding and put forward the short circuit fault between rotor inter-turns causing the potential difference and circulation between the parallel branches of generation stator winding spectral method was applied on the spectrum analysis...
The purpose of this paper is to propose an interesting combination of two different types of switched reluctance generators (SRG) as a suitable prototype to produce electrical energy using variable speed energy resources such as wind turbines. The paper focuses on the amount of electric efficiencies of these two generators when they are utilized as the suitable candidates to produce electric power...
In this paper, Optimal design basis of dual winding induction generator for minimizing to reactive power of control winding with converter under variable speed are proposed. A optimal prototype is presented. The experiment results based on dSPACE show the capacitance ratio between control winding and power winding is very small with 2:1 speed variable range, which is help to minish capacitance of...
This paper describes a new robust fault detection strategy to detect stator winding fault in induction motors. Because of the destructive and rapidly propagation of stator winding fault, it is critical to detect it as soon as possible. The proposed approach is based on Unknown Input Observer (UIO) and Extended Kalman Filter (EKF). The EKF and UIO have been used for speed estimation and fault detection...
Brushless Doubly-Fed Machine (BDFM) is a machine which incorporates the robustness of the squirrel cage induction machine while having the speed and power factor control of a synchronous machine. A special kind of rotor called Nested-Loop rotor plays an important part in the BDFM, coupling the two stator fields. In future BDFM will share a large part in wind power market. This paper presents a mathematical...
The use of partial discharge (PD) online monitoring as an indicator of hydro-generator stator insulation condition, is well known. In this paper, a set of partial discharge online monitoring system for hydro generator (HPDMS) with the characteristics of high reliability is developed, and the de-noise method of the system is introduced, In succession, the influence of PD sensors installation on hydro-generator's...
In this paper the finite element model of the Brushless Doubly-Fed Machine is presented. A magnetodynamic finite element model allowing the simulation of the healthy and faulted machine with its special rotor topology is extracted and simulated. To verify the validation of the proposed model the results are compared with couple circuit model, which used generalized harmonic theory.
This paper proposes a method for reduction of cogging torque with reduced stator tooth width and bifurcated active surface area using Finite Element analysis. For the proposed changes in the motor design the variation in the flux density distribution in the air gap, cogging torque and reluctance torque ripple are determined. The variations in the torque developed by the motor, cogging torque, output...
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