An electronic device includes a circuit board having a signal detection terminal disposed on a first surface thereof and a ground terminal disposed on a second surface thereof and extending vertically so that the first surface and the second surface face each other in a horizontal direction, a monitoring terminal connected with the signal detection terminal, and a microcontroller unit (MCU) determining whether there is submersion by monitoring a voltage at the monitoring terminal. According to the present embodiments, it is possible to prevent hypersensitivity-induced misdetection due to condensation and dew. It is also possible to stepwise respond to submersion and determine whether the monitoring circuit normally operates to precisely detect submersion.

An electronic device includes a circuit board having a signal detection terminal disposed on a first surface thereof and a ground terminal disposed on a second surface thereof and extending vertically so that the first surface and the second surface face each other in a horizontal direction, a monitoring terminal connected with the signal detection terminal, and a microcontroller unit (MCU) determining whether there is submersion by monitoring a voltage at the monitoring terminal. According to the present embodiments, it is possible to prevent hypersensitivity-induced misdetection due to condensation and dew. It is also possible to stepwise respond to submersion and determine whether the monitoring circuit normally operates to precisely detect submersion.

An object of the present invention is to propose a partial discharge determination device and method that can highly reliably determine the degree of progress of partial discharge occurring in an underground power transmission cable without preparing plural standard patterns. A distribution pattern of a set of the charge amount and the occurrence phase angle of each partial discharge occurring in a period of one or more cycles of an applied voltage of a power transmission cable is sequentially generated, a first classification process in which the pattern is classified into any one of classes on the basis of a standard distribution pattern for each class and a second classification process in which the distribution pattern are executed, a classification result by the first classification process is evaluated on the basis of a classification result by the second classification process, and the degree of progress is determined.

An object of the present invention is to propose a partial discharge determination device and method that can highly reliably determine the degree of progress of partial discharge occurring in an underground power transmission cable without preparing plural standard patterns. A distribution pattern of a set of the charge amount and the occurrence phase angle of each partial discharge occurring in a period of one or more cycles of an applied voltage of a power transmission cable is sequentially generated, a first classification process in which the pattern is classified into any one of classes on the basis of a standard distribution pattern for each class and a second classification process in which the distribution pattern are executed, a classification result by the first classification process is evaluated on the basis of a classification result by the second classification process, and the degree of progress is determined.

A ground fault detection device connected to a high-voltage battery and a positive electrode side Y capacitor includes a detection capacitor operating as a flying capacitor and a discharge circuit including at least a fifth switch. A one end of the discharge circuit is connected to a first circuit that connects a positive electrode side of the high-voltage battery and a one end of the detection capacitor. An another end of the discharge circuit is connected to a second circuit that connects an another end of the detection capacitor and a ground.

A ground fault detection device connected to a high-voltage battery and a positive electrode side Y capacitor includes a detection capacitor operating as a flying capacitor and a discharge circuit including at least a fifth switch. A one end of the discharge circuit is connected to a first circuit that connects a positive electrode side of the high-voltage battery and a one end of the detection capacitor. An another end of the discharge circuit is connected to a second circuit that connects an another end of the detection capacitor and a ground.

An earth fault detection apparatus includes a switch group configured to switch between a first measurement path including a battery and a capacitor, and a second and third measurement paths including the battery, a positive/negative-side insulation resistance, and the capacitor; a reference resistance and a test switch; and a control unit calculating a first reference value based on each charging voltage in a case where the test switch is opened and the capacitor is charged, and calculating the insulation resistance with reference to a conversion map created to correspond to an electrostatic capacitance between a power supply line and ground, wherein the control unit calculates a second reference value based on each charging voltage in a case where the test switch is closed and the capacitor is charged for a shorter time, and estimates the electrostatic capacitance with reference to a predetermined test conversion map.

An earth fault detection apparatus includes a switch group configured to switch between a first measurement path including a battery and a capacitor, and a second and third measurement paths including the battery, a positive/negative-side insulation resistance, and the capacitor; a reference resistance and a test switch; and a control unit calculating a first reference value based on each charging voltage in a case where the test switch is opened and the capacitor is charged, and calculating the insulation resistance with reference to a conversion map created to correspond to an electrostatic capacitance between a power supply line and ground, wherein the control unit calculates a second reference value based on each charging voltage in a case where the test switch is closed and the capacitor is charged for a shorter time, and estimates the electrostatic capacitance with reference to a predetermined test conversion map.

A ground fault detection device includes: a detection capacitor; a switch group for switching between a first charging path connecting the battery and the detection capacitor, a second charging path connecting the battery, a negative side insulation resistance and the detection capacitor, a third charging path connecting the battery, a positive side insulation resistance and the detection capacitor, and a measurement path for measuring a charging voltage of the detection capacitor; and a controller configured to calculate the insulation resistance based on a charging voltage measured value of the detection capacitor which exists after charging each of the charging paths, wherein after measurement of the charging voltage of the second charging path, the controller is configured to cause the switch group to switch to the third charging path before switching to the first charging path.

A ground fault detection device includes: a detection capacitor; a switch group for switching between a first charging path connecting the battery and the detection capacitor, a second charging path connecting the battery, a negative side insulation resistance and the detection capacitor, a third charging path connecting the battery, a positive side insulation resistance and the detection capacitor, and a measurement path for measuring a charging voltage of the detection capacitor; and a controller configured to calculate the insulation resistance based on a charging voltage measured value of the detection capacitor which exists after charging each of the charging paths, wherein after measurement of the charging voltage of the second charging path, the controller is configured to cause the switch group to switch to the third charging path before switching to the first charging path.