Abstract: A deterioration determination device that determines deterioration of a reactor and a smoothing capacitor included in a power conversion device, includes: a storage unit that stores a charge determination value based on a voltage change when the smoothing capacitor with no deterioration is charged by a power source electric power supplied through the reactor with no deterioration; and a calculation unit that determines at least one of the reactor and the smoothing capacitor has deteriorated when the voltage change the smoothing capacitor during charging by the power source electric power supplied through the reactor is larger than the charge determination value.

Abstract: A power control apparatus has a plurality of switch units, a cooling unit, and an electronic control circuit. The electronic control circuit is configured to perform: measuring temperatures of each of the plurality of switch units; comparing the temperatures of each of the plurality of switch units measured in the measuring step; and determining whether a temperature difference between any two of the plurality of switch units is greater than or equal to a threshold value based on information from the comparing step.

Abstract: A bus bar for a plurality of capacitor elements having an equal impedance includes a positive electrode bus bar and a negative electrode bus bar. The positive electrode bus bar and the negative electrode bus bar each includes a main bus bar and branch bus bars. The main bus bar is electrically connected to an electric circuit having a switching element. First ends of the branch bus bars are connected to the main bus bar at different positions, and second ends of the branch bus bars are connected to the capacitor elements. The branch bus bars are configured so that an impedance between the first end and the second end reduces as an impedance between a connecting portion of the main bus bar to the electric circuit and a connecting portion of the first end of the branch bus bar to the main bus bar increases.

Abstract: A power converter includes a rectangular casing that houses a semiconductor module, and bosses extending outward from three of four side walls of the casing excluding a rear side wall. The bosses include a first boss provided on a first side wall facing frontward, a second boss provided on a second side wall facing in a width direction of the mobile object orthogonal to an up-down direction and a front-rear direction, and a third boss provided on a third side wall opposite to the second side wall. The third boss is smaller in cross-sectional area than the second boss.

Abstract: A power conversion device includes a semiconductor module group including a plurality of semiconductor modules having a semiconductor element and a main terminal, a dummy module, a cooler having a plurality of heat exchange portions, a capacitor module, and a bus bar. The semiconductor module and the dummy module are arranged side by side, and the heat exchange portions are arranged so as to sandwich each of the semiconductor module and the dummy module from both sides so as to form a laminated body. The bus bar electrically connects the capacitor module and the main terminal. The dummy module has a metal body and a dummy terminal which continues from the metal body and connects to the bus bar. The metal body forms at least a part of the surface of the dummy module sandwiched by the heat exchange portion.