METHOD TO MEASURE RESISTANCE OF INSULATION AND TO PROTECT AGAINST SHORT CIRCUITS TO BODY IN POWER CIRCUITS OF DIESEL LOCOMOTIVES Russian patent published in 2013 - IPC G01R27/18 

FIELD: measurement equipment.

SUBSTANCE: in the method to measure resistance of insulation and to protect against short circuits to a body in power circuits of diesel locomotives, based on connection of a circuit of two serially connected resistors to poles of a DC circuit, in the place of resistor connection to each other there are some ends of two measurement circuits connected, the first measurement circuit comprises a resistor, a voltage sensor and diode. The second measurement circuit comprises the second resistor, the second voltage sensor and the second diode connected in polarity, which is reverse relative to the first measurement circuit, other ends of the first and second measurement circuits are connected to the grounding element. In process of measurement they measure voltage drops at resistors in the first and second measurement circuits. Voltage is measured at poles of the DC circuit. On the basis of these parameters they calculate resistance of insulation separately in a positive circuit and separately in a negative circuit, and if one of these resistances drops down to the specified threshold value, it is assumed there was a breakthrough of insulation in the appropriate circuit, and the decision is made to implement protection by removal of excitation off a generator, which supplies to the power circuit of the diesel locomotive.

EFFECT: increased reliability and stability of the method due to monitoring of condition of insulation resistance in power circuits of diesel locomotives under continuously alternating voltage with simultaneous permanent realisation of protection against insulation breakthrough to a body.

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