Implementations described herein relate to methods, apparatuses, and systems of leakage current detection. According to one implementation, a method includes initiating self-test of a resistive isolation detection circuit, the self-test configured to return a reset latched value representative of a state of the resistive isolation circuit, pulsing a latch reset signal to clear the reset latched value and a testing signal to indicate a testing state, and during the testing signal, independently determining, that a leakage current is present between a photovoltaic power conversion device positive channel and earth, and, that a leakage current is present between a photovoltaic power conversion device negative channel and earth. The method also includes operating a safety relay and indication signal responsive to the testing signal and the independent determining.

Implementations described herein relate to methods, apparatuses, and systems of leakage current detection. According to one implementation, a method includes initiating self-test of a resistive isolation detection circuit, the self-test configured to return a reset latched value representative of a state of the resistive isolation circuit, pulsing a latch reset signal to clear the reset latched value and a testing signal to indicate a testing state, and during the testing signal, independently determining, that a leakage current is present between a photovoltaic power conversion device positive channel and earth, and, that a leakage current is present between a photovoltaic power conversion device negative channel and earth. The method also includes operating a safety relay and indication signal responsive to the testing signal and the independent determining.

A converter system includes a plurality of converters, a sampling circuit, and a control circuit. The plurality of converters are connected in parallel. Each converter includes a detection circuit which includes a first switch and at least two resistors. The first switch is connected in parallel with one of the at least two resistors. The control circuit control the sampling circuit to collect a first voltage and a second voltage, where the first voltage is a voltage that is between a second bus and a ground cable and that is collected by the sampling circuit when first switches in detection circuits of a first quantity are in a turn-on state, the second voltage is a voltage that is between the second bus and the ground cable and that is collected by the sampling circuit when first switches in detection circuits of a second quantity are in a turn-on state.

An electric aircraft charging connector, including a direct current pin and/or an alternating current pin. The connector including a ground pin, the ground pin providing a grounded connection. The connector also including a resistance sensor, the resistance sensor electrically connected to the direct current pin and/or the alternating current pin, and the ground pin, the resistance sensor configured to measure a resistance datum, the resistance datum including: a first resistance, the first resistance comprising a measurement of resistance between the direct current pin and the ground pin; and a second resistance, the second resistance comprising a measurement of resistance between the alternating current pin and the ground pin. The connector also including a controller, the controller configured to: receive the resistance datum from the resistance sensor; and compare the resistance datum to a threshold resistance datum.

An electric circuit according to an embodiment of the present disclosure includes only a single amperemeter configured to measure either a positive current or a negative current through a respective measurement resistance between a respective high voltage potential and a common ground potential. The respective actual measurement resistance value of the unmeasured measurement resistance is calculated by applying a respectively calculated actual measurement resistance value of the respective measured measurement resistance, a calculated actual positive isolation resistance value, and a calculated negative isolation resistance value.

A method of monitoring a battery system comprises connecting a voltage divider circuit to a battery of the battery system; measuring a first battery voltage; sampling a first chassis voltage for less than a settling time of the first chassis voltage and estimating a settled value of the first chassis voltage using sampled values of the first chassis voltage; changing a configuration of the voltage divider circuit; measuring a second battery voltage; sampling a second chassis voltage for less than a settling time of the second chassis voltage and estimating a settled value of the second chassis voltage using sampled values of the second chassis voltage; and determining isolation impedance of the battery to a chassis using the first and second battery voltages and the estimated settled values of the first and second chassis voltages.

An insulation resistance detection system for an electric vehicle is used to detect a positive insulation resistance between a positive electrode of a battery of the electric vehicle and an equipment grounding point, and detect a negative insulation resistance between a negative electrode of the battery and the equipment grounding point. The insulation resistance detection system includes a negative detection circuit, a positive detection circuit, and a control unit. The control unit controls the negative detection circuit to be charged to generate a first capacitor voltage, and controls the positive detection circuit to be charged to generate a second capacitor voltage. The control unit determines whether the negative insulation resistance is abnormal according to the first capacitor voltage and a battery voltage of the battery, and determines whether the positive insulation resistance is abnormal according to the second capacitor voltage and the battery voltage.

A monitoring apparatus for monitoring of an electrical energy source features one measuring circuit for each pole of the energy source, which is designed to connect the particular pole via a voltage divider to the reference potential. An evaluating device is provided to detect a particular voltage value at the particular voltage divider and based on the detected voltage values, determines a source voltage datum for the source voltage of the energy source. For at least one of the measuring circuits the total electrical resistance is dependent on a switch state of a particular switching element, and the evaluation device is designed, by switching of the particular switching element, to adjust at least two different switching constellations of the measuring circuits, and based on the voltage values detected for the switching constellations, determines overall resistance data for isolation resistances of the energy source.

Embodiments of this application relate to the monitoring field, and disclose a method for monitoring an insulation monitoring circuit and a battery management system. In some embodiments of this application, the method for monitoring an insulation monitoring circuit includes: in a state in which a first switch and a second switch are closed and a third switch is open, obtaining a first electrical signal detected by a second monitoring module; and based on the first electrical signal and a voltage reference value between a positive electrode of a battery pack and a negative electrode of the battery pack, determining whether an insulation monitoring circuit is faulty; or obtaining a second electrical signal detected by a first monitoring module and a third electrical signal detected by a third monitoring module, and based on the second electrical signal and the third electrical signal, determining whether the insulation monitoring circuit is faulty.

Dynamically monitoring of an electrically-isolated power bus for a DC power system is described, and includes dynamically monitoring voltage and current on the power bus to determine a variation in the voltage on the power bus. When the variation in the voltage on the power bus is less than a threshold, an active positive isolation resistance term and an active negative isolation resistance term are determined. A first voltage balance term is determined based upon a ratio of the active positive isolation resistance term and the active negative isolation resistance term. A dynamic positive isolation resistance term and a dynamic negative isolation resistance term are determined based upon the active negative isolation resistance term. A fault associated with the power bus is determined based upon the dynamic positive isolation resistance term and the dynamic negative isolation resistance term.