METHOD FOR AUTOMATIC CONTROL OF INSULATION OF THE DIRECT CURRENT POWER SOURCE RELATIVE TO THE HOUSING AND RELATIVE TO EACH OTHER AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2018 - IPC G01R27/18 G01R31/02 

FIELD: measuring equipment.

SUBSTANCE: invention relates to electrical measuring equipment, in particular to automated monitoring systems, and is used to control the insulation resistance of power lead of electrically isolated direct current power supply relative to the housing and to each other. Method of measuring the insulation resistance in direct current circuits is based on connecting to the poles of the direct current circuit resistors consisting of two connected in sequence resistors with the same resistance value. Measuring circuit is connected to the connection point of the resistors made from the connected in sequence source of the measuring voltage and the current meter. Effective resistance of the resistor circuit is then determined. In the measuring circuit includes a measuring voltage source with a single voltage value, the value of which may be equal to zero, then with the other, different from zero. Values of the measuring currents for two values of the measuring voltages is determined, algebraic difference of the measuring voltages is calculated, it is divided by the algebraic difference of the measured currents, and the result of dividing the modulo,subtract the value of the equivalent resistance. To measure the insulation resistance between two galvanically isolated direct current sources, connect between the junctions of two circuits of resistors with the same values of the resistances included between the poles of the corresponding sources of direct current, while the subtracted equivalent resistance is equal to the nominal resistance value of the resistors of the circuits. Method for measuring the insulation resistance is implemented in a device that contains a circuit of identical resistors connected in series, connected to the poles of a direct current source to measure its insulation resistance relative to the housing, a measuring circuit consisting of a series-connected source of measuring voltage and a current sensor, as well as measuring voltage commutator having a control input, a controller with an analog input connected to a current sensor, and a controller output having an electrical connection to the control input of the voltage measuring commutator. Additionally, two commutators are introduced, each of which has n+1 input, one output and control input, a resistor connected between the n+1 input of the first commutator and n+1 by the second commutator input, a serial device. In addition, n-1 additional circuits of series-connected resistors are introduced, the measuring circuit is connected between the outputs of the entered commutators, and the measuring voltage commutator with its output is connected in parallel with the source of the measuring voltage.

EFFECT: technical result of the invention is to increase the accuracy of determining the values of insulation resistance relative to the housing, and the possibility of insulation monitoring of tires of several galvanically isolated direct current sources as relative to the housing, and in off and in on state.

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