METHOD TO MEASURE RESISTANCE OF INSULATION AND PROTECTION AGAINST CHASSIS FAULTS IN POWER CIRCUITS OF DIESEL LOCOMOTIVES Russian patent published in 2011 - IPC G01R27/18 

FIELD: electricity.

SUBSTANCE: configuration of measured circuit is modified by shunting, and some measurements of measured circuit are taken, when in the beginning of measurement potentials of various circuit sections are measured relative to body, then circuit section is shunted with a resistor of available nominal, and values of potentials of the same circuit sections are measured in established mode. These parametres are used to calculated resistance of insulation in separately positive and negative circuits. Simultaneously distribution of voltages is permanently controlled between poles of circuit and body, and in case one of these voltages drops down to value, which is close to zero. Provided that other voltage is in the range of previously selected threshold, it is assumed that there has been a breakdown of insulation in according circuit, and decision is made to implement protection by de-energising generator that supplies to power circuit.

EFFECT: higher accuracy of measurement.

1 dwg