| 摘要 |
The invention relates to a device in high-power motors, especially railway motors, for protection against flashovers between brush apparatuses of opposing polarity and between brush apparatuses and the housing. In high-power traction motors, flashovers between brush apparatuses and the housing occur repeatedly as a result of the high operating voltages and the extreme traction conditions. The device according to the invention avoids the above disadvantages and is characterised in that protection electrodes are arranged in pairs in the immediate vicinity of the brush apparatuses and are connected to the housing in DC terms. The invention for the first time makes it possible to avoid severe damage to the motors and also disturbances. The protection electrodes according to the invention in normal operation prevent discharges between the commutator and electrodes, and between brush apparatuses and electrodes. If disturbances occur, such as overvoltages or spatial discharges in this region, then an electrical discharge occurs between the electrodes, which are coupled electrically and in a moving manner to the housing potential, and brush apparatus or commutator, and the protection electrode is briefly raised to the potential of the opposing electrode and the arc is extinguished. The original state in terms of potential is produced again by means of discharge resistors. |
