Transformer assembly including a first transformer stage having a plurality of first-stage transformer cells; and a second transformer stage. An input of the second transformer stage is connected to an output of the first transformer stage. A lightning impulse breakdown voltage of a transformer cell of the second stage is at least double of a lightning impulse breakdown voltage of transformer cells of the first stage.

The insulation deterioration monitoring apparatus comprises a computer on which software is installed. The software causes the computer to execute at least first to fourth processes. In the first process, during stopping of at least one inverter unit, the computer selects one inverter unit out of the stopped inverter units and causes the inverter corresponding to the selected inverter unit to generate a direct current voltage. In the second process, the computer measures the current value of the ground current while the corresponding motor driving inverter generates the direct current voltage. In the third process, the computer records the measured current value of the ground current for each inverter unit in association with the selected inverter unit. Then, in the fourth process, based on the measured current value of the ground current recorded for each inverter unit, the computer analyzes the tendency of insulation deterioration of each inverter unit.

The insulation deterioration monitoring apparatus comprises a computer on which software is installed. The software causes the computer to execute at least first to fourth processes. In the first process, during stopping of at least one inverter unit, the computer selects one inverter unit out of the stopped inverter units and causes the inverter corresponding to the selected inverter unit to generate a direct current voltage. In the second process, the computer measures the current value of the ground current while the corresponding motor driving inverter generates the direct current voltage. In the third process, the computer records the measured current value of the ground current for each inverter unit in association with the selected inverter unit. Then, in the fourth process, based on the measured current value of the ground current recorded for each inverter unit, the computer analyzes the tendency of insulation deterioration of each inverter unit.

The present invention discloses an insulation detection circuit and a detection method thereof for a two-way on-board charger. The detection circuit comprises an inverter circuit, a first Y capacitor connected between an output live line and a ground line of the inverter circuit, a second Y capacitor connected between an output neutral line and the ground line of the inverter circuit, a live line sampling circuit and a neutral line sampling circuit which are connected with the output live line and the output neutral line of the inverter circuit, and a controller. The controller determines an insulation state of the two-way on-board charger according to two sampling voltages.

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.

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).

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).

Systems and methods for detecting and identifying arcing are disclosed. A method of detecting arcing includes obtaining data indicative of voltage and data indicative of current, determining a waveform of a cycle of a primary load current according to the data indicative of current, determining at least one noise signal according to the determined waveform of a cycle of the primary load current and the data indicative of current, determining a probability density of the noise signal according to a time window, and comparing the probability density of the noise signal with at least one model probability density.

Systems and methods for detecting and identifying arcing are disclosed. A method of detecting arcing includes obtaining data indicative of voltage and data indicative of current, determining a waveform of a cycle of a primary load current according to the data indicative of current, determining at least one noise signal according to the determined waveform of a cycle of the primary load current and the data indicative of current, determining a probability density of the noise signal according to a time window, and comparing the probability density of the noise signal with at least one model probability density.