A stack module fault detection system, comprising an insulation resistance tester; a stack module, consisting of a plurality of stacks; and a plurality of switch groups, wherein each switch group comprises a first switch and a second switch, each switch group is respectively connected with a stack, the first end of the first switch is connected with the positive electrode of the stack, and the first end of the second switch is connected with the negative electrode of the stack; the second end of the first switch is connected with the positive electrode of the insulation resistance tester, and the second end of the second switch is connected with the negative electrode of the insulation resistance tester. A controller connected with the control end of the switch group controls the opening and closing of the switch group. The insulation resistance tester detects the insulation resistance of each stack in turn and sends the insulation resistance to the controller to monitor the insulation fault in the stack module. Under the condition of not disassembling the stack module, the insulation resistance of each stack is detected, and the stack with insulation fault can be located, so that the operation of fault positioning is simplified.

A method and a photovoltaic inverter for determining the insulation resistance of a photovoltaic system relative to ground are provided. The voltage required for the measurement can be provided by an intermediate circuit in the form of an intermediate circuit voltage and a measuring device is designed to actuate an input short-circuit switch for short-circuiting a DC input with an AC disconnector open, as a result of which the intermediate circuit voltage can be applied to the DC input in the reverse direction. The measuring device is configured to record measured voltages with a switch of a voltage divider open and closed, and to determine the insulation resistance from the measured values of the two measured voltages recorded with the switch of the voltage divider open and closed.

A method determines an insulation resistance of the high-voltage network in an electric or hybrid vehicle, in which a controllable continuous voltage source connected to the body and to a single first terminal of a high-voltage battery of the vehicle is provided, a first resistor being connected in series to the source between the single first terminal and the body and a second resistor being connected in series between the first resistor and the source, consecutive voltage setpoint values are applied between the body and the single first terminal, a measurement signal of the voltage at the terminals of the second resistor is acquired for each setpoint value, adaptive filtering of the signal is carried out and an estimate made, in a recursive manner, of a vector of the filter transfer function coefficients, providing an update of the filtering coefficients, the insulation resistance being determined based on the estimate.

The present application provides a stack module fault monitoring system, comprising an insulation resistance tester; a stack module, which consists of m groups of stack strings; m electronic switch groups, wherein each electronic switch group comprises a first switch and a second switch; one end of the first switch is connected with positive electrodes of one group of stack strings, and the other end of the first switch is connected with a positive electrode end of the insulation resistance tester; one end of the second switch is connected with negative electrodes of the group of stack strings, and the other end of the second switch is connected with a negative electrode end of the insulation resistance tester; a control end of a switch in the electronic switch group is connected with a controller, and the switch in the electronic switch group is controlled to be on and off by the controller; the insulation resistance tester tests the insulation resistance of each group of stack strings in sequence and sends the insulation resistance to the controller; the controller determines whether the group of stack strings has then insulation fault or not according to the insulation resistance, so as to realize online monitoring on whether each group of stack strings has the insulation fault or not, and quickly position the stack string with the insulation fault in the stack module.

In a method for inspecting the insulation property of a secondary battery by connecting an external DC power supply to the secondary battery charged with an initial charge amount and evaluating the insulation property of the secondary battery based on a converging state of a power-supply current, when a charge amount at which an inclination of a tangent to a charge amount—battery voltage curve representing a relationship between the charge amount and a battery voltage of the secondary battery is smallest is assumed as a minimum-inclination charge amount, and the inclination of the tangent at the minimum-inclination charge amount is assumed as a minimum inclination (αL), the initial charge amount is selected from a range of the charge amount in which the inclination is two or more times the minimum inclination.

The disclosure relates to an insulation resistance detection device and a forklift truck. The insulation resistance detection device includes a detection module, a voltage conditioning module, and a control module. The device uses a first voltage dividing unit and a second voltage dividing unit to replace the inverting amplifier circuit, to obtain a positive voltage corresponding to the voltage of the negative electrode of the battery to be detected with respect to the first reference ground, thereby reducing costs of the insulation resistance detection device. The control module calculates the first insulation resistance of the positive electrode of the battery to be detected with respect to the first reference ground and the second insulation resistance of the negative electrode of the battery to be detected with respect to the first reference ground according to the first voltage and the third voltage.

This application provides an insulation resistor detection circuit, which includes a state control unit, which is connected between a positive electrode and a negative electrode of a power supply of a to-be-detected apparatus; a first voltage division branch that is connected in parallel to a first capacitor to obtain a first voltage waveform, a second voltage division branch that is connected in parallel to a second capacitor to obtain a second voltage waveform; and a processor that is connected to the state control unit, the first voltage division branch, and the second voltage division branch; determines a next switching moment based on the first voltage waveform and the second voltage waveform that are at a current moment; and control, at the next switching moment, the state control unit to switch a state.

A method is provided for checking the plausibility of insulation monitoring of a high-voltage system (100) of an electric vehicle during the charging of a traction battery of the electric vehicle. The electrical insulation of the high-voltage system (100) is monitored by an insulation monitoring device (101), and a check is carried out cyclically to determine whether a further insulation monitoring device is active on a high-voltage bus of the high-voltage system (100).

It is disclosed an insulation impedance detection circuit and detection method of a photovoltaic inverter system. The photovoltaic inverter system includes one or more input circuits and an inverter circuit, each of the input circuit electrically coupled to the inverter circuit through a positive bus and a negative bus, with a first equivalent impedance R.sub.p between the positive bus and a protective earth point and a second equivalent impedance R.sub.n between the negative bus and the protective earth point. The detection circuit includes: a bus voltage sampling circuit coupled to the positive bus and the negative bus for generating a first bus voltage and a second bus voltage; a protective earth voltage sampling circuit coupled to the protective earth point for generating a first protective earth voltage and a second protective earth voltage; and a controller for calculating an equivalent insulation impedance.

An input sensor short-circuit inspection method including: setting an inspection frequency for detecting a short-circuit of an input sensor comprising a plurality of electrodes; driving the input sensor in an inspection mode at the set inspection frequency; and detecting the short-circuit of the input sensor based on a capacitance charged between adjacent electrodes among the plurality of electrodes of the input sensor in the inspection mode.