Adrian Munteanu

Induction Motor With Outer Rotor and Ring Stator Winding for Multispeed Applications

This paper presents a complex study of the performance developed by an outer rotor induction motor with multipole stator winding. The novelty of the proposed structure consists in the replacement of the regular lap winding with a ring type one, which allows a higher flexibility in changing the number of pole pairs. The purpose is mainly to obtain a superior torque capability by changing the synchronous speed. This study is based on FEM, Simulink analyses, and experimental tests. A startup strategy for the reduction of starting time, current, and electric power consumption is developed as well.

Design and finite element analysis of high-density torque induction motor for traction applications

The paper presents the design and FEM simulation of a novel induction motor intended as a specialized drive for electric traction and/or airborne propulsion applications. Several particular requirements related to the size, weight and dynamics did rise non-conventional challenges and therefore a less-than classical approach have been considered. The proposed solution consists in a combination of an external rotor mated with an internal stator with ring coils. Furthermore, the coils arrangement may be reconfigured on-the-fly, allowing operation with two distinct synchronous speeds (different number of poles), solution which largely fulfills all the requirements.

About the dynamic contact resistance of the circuit breakers

This paper presents the parameters that are required in the monitoring and diagnostic of the circuit breakers and aspects concerning the dynamic contact resistance. Also, it is presented the experimental results obtained on two circuit breakers of medium voltage with SF6, at closing and opening, which are analyzed from the point of view of dynamic contact resistance.

Considerations regarding the influence of contact resistance on the contacts of low voltage electrical equipment

The electrical contacts are important elements which can be found on all of the electrical installations from the power source to the consumer. Also, the electrical contacts have an important role in the construction and operation of low voltage electrical equipment. The presence of an electrical contact on a current path always introduce an additional electrical resistance, named contact resistance. In this paper is studied the influence of the voltage drops to contact resistance, respectively to contact temperature of the low voltage electrical equipment.

Modeling and simulation of a supply system from electric traction

This paper presents the supply system used in electric traction of single-phase with 25 kV, 50 Hz which was modeled in Electromagnetic Transients program (EMTP). It simulates the influence of contact resistances in return circuit for different loads of locomotive on three circulation sectors. Also, it is presented the influence of inductances in return circuit for different loads.

Aspects concerning the influence of environmental factors in infrared monitoring of electrical equipment

This paper presents the influence of the environmental factors over the electrical equipment thermal stresses when it is monitored with infrared monitoring device. A good definition of the correction parameters for this monitoring device and the choice of the optimal conditions for monitor performing can lead to good results. In particular, the paper presents the influence of the dust layer from electrical equipment over the captured thermal image by the infrared monitoring device and further more to estimate its thermal stress. To achieve this, it was used an experimental stand where a copper bar was split in different areas and they were covered with different dust types and in the end the thermal stress of each area was estimated with the infrared monitoring device.

Using fuzzy logic for diagnosis of technical condition of power circuit breakers

Monitoring and diagnosis of power circuit breakers represent an important activity for increase the reliability and safety in power system. In order to deal with the uncertain information in the process of diagnosis, the paper presents a diagnosis system based on fuzzy logic which has the role to acquire information about the monitored equipment for faults detection. Also, the paper describe the LabVIEW software application based on fuzzy logic used for diagnosis of power circuit breakers which enable to generate alarms when something it is wrong with the electrical equipment.

Three phase squirrel-cage induction motor optimization using finit element method

This paper presents the results of an optimization process on a three phase squirrel-cage induction motor designed for mining applications. In order to achieve the imposed working characteristics (limited start-up current and convenient torque values), deep rotor bars and double cage solutions have been considered and analyzed. For this aim, the finite element method (FEM) has been used. The obtained simulation results were compared in order to find the most suitable solution for the specified application, considering the influence of each design upon the motor performance.

Design And FEM Simulation Of A Fractional Power Three-Phase Induction Motor For Oil-Submerged Applications.

The paper reports design and FEM simulation comments on a fractional power three-phase induction motor with severe constraints as regards frame size and supply electric parameters. The simulation stage consists in magnetodynamic and transient analyses both in 2D and multilayer approach. The study takes into consideration different topologies (straight or skewed rotor slots, open or closed rotor slots) and two types of laminated silicon steels (with regular and premium magnetization curve) and put in view advantages and drawbacks upon motor performance.

Influence of operational voltage on switching time of the circuit breakers

This paper refers to the magnetic actuator from vacuum circuit breaker. The actuator is one of the main component with functions for switching, latching and release. Due to the low quality of power supply of actuator, undesirable effects such as the delay during the operation of connecting or disconnecting the circuit breaker can result. As case of study to observe this delay was used a monopolar vacuum circuit breaker with to measure the operating time.