Patent application number | Description | Published |
20120105235 | METHOD FOR IDENTIFYING DIRT AND/OR DEW ON COMPONENTS OF A VOLTAGE INTERMEDIATE CIRCUIT CONVERTER - The invention relates to a method for identifying dirt and/or dew on components of a voltage intermediate circuit converter. According to the invention, the temporal curve of a partial discharge pulsed current is detected at least during a precharging process of an intermediate circuit capacitor of the voltage intermediate circuit converter comprising at least one capacitor, wherein a frequency spectrum is calculated from said current pulse, and wherein depending of the result, a dirt warning and/or a dew warning is activated. Thus, the degree of dirt and/or dew of said voltage intermediate circuit converter can be determined at least during a charging process of an intermediate circuit capacitor of a voltage intermediate circuit converter, thereby preventing a breakdown including the consequences thereof. | 05-03-2012 |
20120319636 | METHOD AND DEVICE FOR ASSESSING THE DAMAGE TO ROLLING BEARINGS, IN PARTICULAR IN INVERTER-FED ELECTRIC MACHINES - A method and device for assessing damage to a rolling bearing caused by bearing currents, in particular high-frequency bearing currents, in an electric machine which is electrically connected to an inverter, in particular to an inverter having a DC voltage link circuit, is described. The rolling bearing has a lubrication gap between an inner bearing ring and a rolling body and between an outer bearing ring and the rolling body. The method includes detecting the energy of an electric discharge event in the lubrication gaps, searching for a coincident event having a frequency above one GHz indicative of a damaging bearing current event, detecting a frequency of occurrence of discharge events, and evaluating the discharge events by correlating the frequency of occurrence and the energy of the discharge events. | 12-20-2012 |
20120319723 | ELECTRIC MACHINE FOR WHICH THE GROUNDING FUNCTION IS MONITORED AND METHOD - The grounding quality of an electric machine should be better monitored. Therefore, an electric machine is proposed, comprising a stator ( | 12-20-2012 |
20120323372 | ELECTRIC ARC DISCHARGE EVALUATION METHOD, AND ASSOCIATED TEST STAND - Electric arc discharges between bearing rings in a roller bearing are analyzed by setting a defined operating state based on rotational speed of the roller bearing, temperature of the roller bearing, an imbalance of the roller bearing causing vibrations, lubricants, axial/radial/tilt loads, tilting of the bearing rings relative to each other, pulse shape and pulse repetition rate of an applied electrical voltage, bearing play, and pre-existing damage to the roller bearing. A pulse-shaped electrical voltage between inner and outer bearing ring generates electric arc discharges, wherein for each electric arc discharge a characteristic value representative of energy, power, voltage and/or current and duration of the electric arc discharge is determined. Only those electric arc discharges are evaluated that have a qualifying value determined in accordance with at least one of the characteristic values greater than a predefined limit value. | 12-20-2012 |
20120330580 | SYSTEM AND METHOD FOR DETERMINING A BEARING STATE - In a system for ascertaining a bearing state and in a method for ascertaining a bearing state of a bearing of an electric machine, measurement value ( | 12-27-2012 |
20130066566 | METHOD AND DEVICE FOR THE EARLY DETECTION OF THE DEVELOPMENT OF DAMAGE IN A BEARING - A method for early detection of developing damage in a bearing caused by flow of a bearing current includes evaluating a long-term measurement of a measured variable representative of a bearing current amplitude of a bearing current during a bearing operation, representing—based on the evaluation—measurement results in form of a histogram which displays a number of bearing currents per time interval in each interval of the bearing current amplitude, and evaluating the histogram representation of the measurement results through pattern comparison. A device for carrying out the method is also disclosed. | 03-14-2013 |
20130270822 | ELECTRIC MACHINE, RAIL VEHICLE AND RAIL-MOUNTED CAR SET - An electric machine has a base body in which a stator of the electric machine is arranged. The electric machine has a rotor shaft which is mounted in the base body in bearings for rotation. The electric machine has a pick-up element connected in fixed rotative engagement with the base body and which taps a voltage present on the rotor shaft. The pick-up element is electrically connected to the base body via a capacitor and/or an ohmic resistor. A capacitance value of the capacitor is at least 1 nF. A resistance value of the ohmic resistor is between 10 mO and 10 O. | 10-17-2013 |