To provide a semiconductor device signal transmission circuit for drive-control, a method of controlling a semiconductor device signal transmission circuit for drive-control, a semiconductor device, a power conversion device, and an electric system for a railway vehicle capable of preventing malfunction due to noise while speeding up or reducing loss of a switching operation. The semiconductor device signal transmission circuit for drive-control that is connected between a semiconductor device constituting an arm in a power conversion device and a drive circuit configured to drive the semiconductor device, including: an inductor; and an impedance circuit including a switch and connected in parallel with the inductor.

A vehicle power delivery assembly that includes a mast configured to couple with a vehicle such that the mast projects from the vehicle, and a collection arm configured to be coupled with the mast in a location apart from the vehicle to engage an off-board source of electric current that is off-board the vehicle while the vehicle moves along one or more routes. One or more of the mast or the collection arm is formed from at least one inductive support member that provides an integrated inductor of the one or more of the mast or the collection arm through which at least some of the electric current that is received from the off-board source of the electric current is filtered prior to being conducted to the vehicle.

An AC electric rolling stock controller includes a comparator that compares an intermediate link voltage V.sub.EFC generated at a smoothing capacitor with a setting value A, a comparator that compares the intermediate link voltage V.sub.EFC with a setting value B less than the setting value A, and a delayer that delays an output of the comparator in a case in which the output of the comparator is significant. It is determined that the initial charging of the smoothing capacitor is complete in a case in which at least one of an output of the comparator and an output of the delayer is significant.

A self-cooled reactor apparatus includes: a pair of frames attached to a vehicular mount, a coil disposed between the pair of frames and fixed to the frames, a cover disposed between the pair of frames, and a protective member. The coil is covered by the cover having at least a portion thereof in which through-holes are formed. The protective member, while retaining a flow passage for air from the through-holes to the coil, blocks a space between the through-hole and the coil in a penetration direction of the through-holes.

A resonant inverter of a power supply for electric vehicle includes a first resonant capacitor and a switching element cutting off a current flowing in a resonant circuit and generates first alternating-current power from direct-current power. The transformer is included in a part of the resonant circuit, supplies the first alternating-current power generated by the resonant inverter to a first winding, and supplies second alternating-current power after conversion of the first alternating-current power to a load from a second winding. A control unit confines a difference between a resonant frequency of the resonant circuit and a switching frequency of the switching element to a predetermined range to cause that a current flowing in switching of the switching element to at least the first winding or the second winding is equal to or less than a predetermined value and to cause the resonant inverter to perform soft switching.

An electric vehicle drive system includes: a reactor; and electric vehicle control apparatuses that control electric motors for driving an electric vehicle. Each of the electric vehicle control apparatuses includes: a capacitor that defines a filter circuit together with the reactor; an inverter circuit that supplies power to the corresponding one of the electric motors; and a control unit that controls the inverter circuit. The inverter circuit is housed in a housing together with the capacitor and the control unit. The reactor is connectable to each of the housings through an electric wire having any desired length. At least one of the electric wires connecting the reactor and the housings has a length of 2 meters or more.

A self-cooled reactor apparatus includes: a pair of frames attached to a vehicular mount, a coil disposed between the pair of frames and fixed to the frames, a cover disposed between the pair of frames, and a protective member. The coil is covered by the cover having at least a portion thereof in which through-holes are formed. The protective member, while retaining a flow passage for air from the through-holes to the coil, blocks a space between the through-hole and the coil in a penetration direction of the through-holes.

A method and system include determining a resonant frequency of a vehicle system operably coupled with an external power source that provides voltage and current to the vehicle system. A first filter extracts a phase or a frequency component from the voltage provided by the external power source to generate a stabilizing voltage component. A second filter extracts a phase or a frequency component from the current provided by the external power source to generate a stabilizing current component. The stabilizing voltage component is out of phase with the stabilizing current component. A control input of a converter device of the vehicle system is determined based on the stabilizing voltage component, the stabilizing current component, and the resonant frequency. The stabilizing voltage component, the stabilizing current component, and the control input are communicated with the converter device to change the resonant frequency of the vehicle system.