A power supply system includes: a power transmission circuit provided on the ground side; a high frequency generation circuit that supplies high-frequency electric power to the power transmission circuit; a measurement unit that measures a physical quantity corresponding to the degree of coupling between the power transmission circuit and a power reception circuit provided in a vehicle; and a control unit. When the degree of coupling is determined, based on the measured physical quantity, to be lower than a predetermined degree, the control unit sets the impedance of the power transmission circuit to a first impedance and thereby sets the power transmission circuit to a non-resonant state. In contrast, when the degree of coupling is determined to be not lower than the predetermined degree, the control unit sets the impedance of the power transmission circuit to a second impedance and thereby sets the power transmission circuit to a resonant state.

In a local cart traveling system, a frame track includes first and second metal rails each with an L-shaped cross section and facing each other. A local cart is within the frame track, and includes a first electricity receiving tire and a second electricity receiving tire to travel on horizontal travel surfaces of the rails. A voltage supplier supplies an AC voltage to the travel surfaces, so that the first metal rail and a first electricity receiving tire define a first capacitor and the second metal rail and the second electricity receiving tire define a second capacitor. The local cart includes a power receiver to receive AC power, and a travel motor that receives power after the AC power is rectified. The frame track includes a connecting plate as an electrical insulator covering portions of the surfaces of vertical walls of the first metal rail and the second metal rail.

In a local cart traveling system, a frame track includes first and second metal rails each with an L-shaped cross section and facing each other. A local cart is within the frame track, and includes a first electricity receiving tire and a second electricity receiving tire to travel on horizontal travel surfaces of the rails. A voltage supplier supplies an AC voltage to the travel surfaces, so that the first metal rail and a first electricity receiving tire define a first capacitor and the second metal rail and the second electricity receiving tire define a second capacitor. The local cart includes a power receiver to receive AC power, and a travel motor that receives power after the AC power is rectified. The frame track includes a connecting plate as an electrical insulator covering portions of the surfaces of vertical walls of the first metal rail and the second metal rail.

In a moving-object power supply system, a control unit selects, as a power transmission segment, one of segments included in at least one power transmission section. The control unit supplies, through a power supply circuit, power to the power transmission segment to thereby generate a magnetic field through a power transmission coil of the power transmission segment. The control unit determines, based on an ascertained first electrical characteristic of the power transmission segment and an ascertained second electrical characteristic of at least one power non-transmission segment, whether there is a malfunction in each of the power transmission segment and the at least one power non-transmission segment.

A coil assembly for wireless electrical power transmission includes a plurality of external connecting terminals, a power feeding coil, a resonant capacitor electrically connecting with the power feeding coil, and busbars each of which electrically connects between the external connecting terminals.

According to some embodiments, a rail transport vehicle electric energy storage and charging system is presented. The system may include an energy storage sub-system and a charging system having a charging rail which only charges a vehicle when the rail is covered. The system may also include a battery-powered rail vehicle having a rail-contacting charging shoe.

A system having electric consumers includes an electrical device including an operating device and wires supplying the consumer. A first wire is provided for conducting the first phase of a three-phase voltage during a normal operation, a second wire conducts a second phase of the three-phase voltage, and a third wire conducts a third phase of the three-phase voltage. The consumer is able to be supplied with the three-phase voltage from the wires during a normal operation. The operating device is configured so that: in a normal operation, the first wire is connected to the first phase of the three-phase voltage; and in a safety case, the first wire is separated from the first phase of the three-phase voltage and will be or is connected to the second phase of the three-phase voltage.

A power transmitter according to one aspect of the disclosure includes: a power converter that converts a first AC power supplied from an AC power source into a DC power; a first detector that detects an electric current of the DC power; a feedback signal generator that generates a feedback signal based on the electric current of the DC power; and a controller that performs a feedback control on the electric power supplied to a power receiver based on the feedback signal. The feedback signal generator generates a canceling waveform to reduce a ripple caused to the DC power due to zero crossing of a voltage of the first AC power and generates the feedback signal based on the electric current of the DC power and the canceling waveform.

The present invention relates to a power supply and pickup system capable of maintaining stability of transmission efficiency despite changes in a resonant frequency. More particularly, the present invention relates to a power supply and pickup system capable of maintaining the stability of efficiency of transmitting power to a pickup device from a power supply device even when a voltage or current changes by the variation in a resonant frequency. According to the power supply and pickup system of the present invention, Q-factor of a power supply and pickup system is set to a low value, a stability of efficiency of transmitting power to a pickup device from a power supply device is maintained even when a voltage of current changes by the variation in a resonant frequency.

The present invention relates to a power supply and pickup system capable of maintaining stability of transmission efficiency despite changes in a resonant frequency. More particularly, the present invention relates to a power supply and pickup system capable of maintaining the stability of efficiency of transmitting power to a pickup device from a power supply device even when a voltage or current changes by the variation in a resonant frequency. According to the power supply and pickup system of the present invention, Q-factor of a power supply and pickup system is set to a low value, a stability of efficiency of transmitting power to a pickup device from a power supply device is maintained even when a voltage of current changes by the variation in a resonant frequency.