Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Three-level modulation techniques to reduce instantaneous common mode voltage in induction machines

Cusidó J., Luna A., Busquets S., Bordonau J., Rodríguez P., Romeral L.

Electrical Power Quality and Utilisation. Journal

2007

Vol. 13, nr 2

33-38

Problems on inverter motor drives such as bearing currents are introduced due to common mode voltages. Different solutions are proposed on literature, for two-level or multilevel inverter. Instantaneous zero common mode voltage by using a three-level inverted could be achieved. This paper proposes a commutation strategy that allows zero common mode voltage by using medium vectors, and also a new representation as a plane on the commutation space is defined which is called zero common mode voltage plane. On this defined plane, every turning vector fulfil this property. Simulations and experimental results clearly show method's efficiency.

New Fault Detection Techniques For Induction Motors

Cusido J., Rosero J., Aldabas E., Ortega J. A., Romeral L.

Electrical Power Quality and Utilisation. Magazine

2006

Vol. 2, iss. 1

39--46

Double frequency tests are used for evaluating stator windings analyzing the temperature. Likewise, signal injection on induction machines is a well-known technique on sensorless motor control fields to find out the rotor’s position. Motor Current Signature Analysis (MCSA) is the most widely used method for identifying faults in induction motors. MCSA focuses its efforts on the spectral analysis of stator current. Motor faults such as broken rotor bars, bearing damage and eccentricity of the rotor axis can be detected. However, the method presents some problems at low speed and low torque, mainly due to the proximity between the frequencies to be detected and the small amplitude of the resulting harmonics respectively. In both cases, the problem of frequency accuracy is very tricky since the sideband harmonic is close to the fundamental harmonic. This paper proposes injecting an additional voltage into the machine under test at a frequency different from the fundamental one, and then studying the resulting harmonics around the new frequencies appearing due to the composition between injected and main frequencies.