DEVICE FOR AUTOMATIC CONTROL OF INSULATION RESISTANCE OF DC POWER SUPPLY NETWORK Russian patent published in 2021 - IPC G01R27/18 G01R15/12 

FIELD: control and measuring equipment.

SUBSTANCE: invention relates to the control and measuring equipment of vehicles with direct current electric traction. The device for automatic control of the insulation resistance of the DC power supply network contains the first K1 and the second K2 switching elements. The input of K1 is connected to the input electrode of the capacitor C, and its output through the discharge resistor R_D is connected to the output grounded electrode of the capacitor C. The inputs of K2 are made with the possibility of alternately connecting to the positive or negative power bus, or disconnecting from the power supply, and its output is connected through an additional resistance R_A to the input electrode of the capacitor C. The means of measuring parameters are made in the form of appropriately connected measurement, calculation and parameter fixation units. The calculation unit is designed to calculate the value of the insulation resistances R_i+, R_i- according to the ratios: where: R_i+, R_i- - insulation resistances of the positive and negative power buses, respectively; U₊, U_- - the voltage on the positive and negative power buses relatively to the “ground” before the start of the charge cycle of the capacitor C; U_C - the voltage on the capacitor charged during the measurement; C - the capacity of the capacitor; t - the capacitor charge time; R_A - the resistance of an additional resistor in the capacitor charge circuit. In the control unit, the calculated values are compared with the values of the resistances from previous measurements and, if these values do not exceed the standard values, these values are recorded in the parameter fixation unit until the next measurement and calculation cycle.

EFFECT: increased accuracy of measurements of insulation resistances of DC network buses, increased electrical safety of operation and increased noise immunity.

1 cl, 1 dwg