FIELD: measuring equipment.
SUBSTANCE: group of inventions relates to electrical measuring equipment and relay protection of isolated power supply systems, in particular to electrical safety of charging electric vehicle traction batteries. Method for controlling the resistance of direct current electrical circuit insulation comprises measuring the voltage between poles of an isolated direct current circuit and the "ground" when the measuring resistive elements are connected between each pole and the "ground" and calculating the insulation resistance values. Switching voltage dividers are used as measuring resistive elements. Dividers are switched in such a way that in the first state the total resistance of the first divider is less than the total resistance of the second one, and in the second state the total resistance of the first divider is greater than that of the total resistance of the second one, wherein the divide factor of each divider is kept unchanged. Device for controlling the direct current electrical circuit insulation resistance comprises two measuring resistive elements, each connected between the respective pole of the circuit and the "ground", an analog-to-digital converter (ADC) and a microcontroller. Each resistive element is made in the form of a divider consisting of four series-connected resistors and a key controlled by the microcontroller. Microcontroller calculates the insulation resistance values and generates signals for subsequent protection and indication devices.
EFFECT: technical result of the invention is the expanded functionality due to providing the ongoing control in the operating mode and increased accuracy of measurements.
2 cl, 1 dwg
