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.

A power converter (10) for operating a first electric machine (12) and a second electric machine (14), comprising:

a first converter element (16), a second converter element (18) and a first terminal connection (21), a second terminal connection (22) and a third terminal connection (23) for connecting the power converter (10) to a three-phase energy supply (60), wherein
the first converter element (16) comprises a first rectifier circuit (31) and a second rectifier circuit (32), the second converter element (18) comprises a third rectifier circuit (33), wherein
the first rectifier circuit (31) has a first AC-side pole (51) and a second AC-side pole (52), the second rectifier circuit (32) has a third AC-side pole (53) and a fourth AC-side pole (54) and the third rectifier circuit (33) has a fifth AC-side pole (55) and a sixth AC-side pole (56),
the first rectifier circuit (31) and the second rectifier circuit (32) are connected in parallel on the DC-voltage side and are connected to a common first DC-voltage-side pole (41) and a common second DC-voltage-side pole (42), wherein
the third rectifier circuit (33) is connected on the DC-voltage side to a third DC-voltage-side pole (43) and a fourth DC-voltage-side pole (44), wherein
the first DC-voltage-side pole (41) is at least connectable to the third DC-voltage-side pole (43) by means of a first current path (36) and
the second DC-voltage-side pole (42) is at least connectable to the fourth DC-voltage-side pole (44) by means of a second current path (37), wherein
at least the first current path (36) or the second current path (37) comprises a semiconductor switch (64).

A power converter for an electric locomotive includes an insulating transformer, an AC/DC converter, an inverter, a PWM controller, and a voltage controller. The insulating transformer is supplied with high-voltage AC power from an AC overhead wire to convert a high voltage to a low voltage and output low-voltage AC power. The AC/DC converter receives the low-voltage AC power and performs AC/DC conversion. The inverter receives an output from the AC/DC converter and performs DC/AC conversion for supply to a load. The PWM controller outputs a PWM control signal having a predetermined pattern, the pattern for removing specific harmonic components from an output of the inverter or attenuating the specific harmonic components to at most a predetermined level. The voltage controller controls a DC output voltage of the AC/DC converter to control an output voltage of the inverter.

A power converter for an electric locomotive includes an insulating transformer, an AC/DC converter, an inverter, a PWM controller, and a voltage controller. The insulating transformer is supplied with high-voltage AC power from an AC overhead wire to convert a high voltage to a low voltage and output low-voltage AC power. The AC/DC converter receives the low-voltage AC power and performs AC/DC conversion. The inverter receives an output from the AC/DC converter and performs DC/AC conversion for supply to a load. The PWM controller outputs a PWM control signal having a predetermined pattern, the pattern for removing specific harmonic components from an output of the inverter or attenuating the specific harmonic components to at most a predetermined level. The voltage controller controls a DC output voltage of the AC/DC converter to control an output voltage of the inverter.

To generate a PWM signal, as an on/off signal of a semiconductor switch that constitutes a power conversion main circuit, by comparing a modulation wave command based on an input voltage waveform command of the power conversion main circuit with a carrier wave having changes from a lower limit to an upper limit and from the upper limit to the lower limit for an integral number of times per one cycle of an AC power supply, where the carrier wave has characteristics such that one change time from the lower limit to the upper limit and then returning to the lower limit is constant, and a time ratio between a change time from the lower limit to the upper limit and a change time from the upper limit to the lower limit changes periodically.

To generate a PWM signal, as an on/off signal of a semiconductor switch that constitutes a power conversion main circuit, by comparing a modulation wave command based on an input voltage waveform command of the power conversion main circuit with a carrier wave having changes from a lower limit to an upper limit and from the upper limit to the lower limit for an integral number of times per one cycle of an AC power supply, where the carrier wave has characteristics such that one change time from the lower limit to the upper limit and then returning to the lower limit is constant, and a time ratio between a change time from the lower limit to the upper limit and a change time from the upper limit to the lower limit changes periodically.

A hybrid drive system includes first and second power supply devices that supply direct-current power; first and second power storage devices are respectively connected to the first and second power supply devices so as to accumulate or discharge the direct-current power; a first load device that receives a supply of the direct-current power from the first power supply device and the first power storage device and drives a first load; and a second load device that receives a supply of the direct-current power from the second power supply device and the second power storage device and drives a second load. The hybrid drive system includes an inter-group contactor for electrically connecting and disconnecting input terminals of the first power storage device and the second power storage device.

A highly efficient, utility scale energy storage system employs large masses transported uphill to store energy and downhill to release energy. An electric powered cable winch or chain drive shuttles the masses between two storage yards of different elevations separated by a steep incline on rail vehicles supported by track and operated by an automated control system.

A voltage estimating device for a power supply line according to one aspect of the present disclosure includes a voltage detector, a current detector, a voltage calculator. The voltage calculator calculates a magnitude of alternating primary voltage that a primary winding in a transformer receives from a power supply line based on a magnitude of tertiary voltage in the transformer detected by the voltage detector, a magnitude of output current in the transformer detected by the current detector, and correlation information. The correlation information indicates a correlation between a voltage ratio and the magnitude of the output current, and the voltage ratio represents a ratio of the magnitude -of the primary voltage to the magnitude of the tertiary voltage.

A monorail vehicle includes a chassis supporting a vehicle body, that includes a passenger floor and at least one side wall, and an electrical motor supported by the chassis. A drive wheel is coupled to a rotor of the electric motor with a rotation axis of the drive wheel substantially coaxial with an axis of the rotor. Portions of the drive wheel and the electric motor are positioned on both sides of an imaginary plane extension of the passenger floor. The drive wheel and the electric motor are covered by a shell that is integral to one side of the vehicle body and which defines a space between the other side of the vehicle body.