A dynamic wireless power transfer system includes a power transmission coil, a power transmission circuit, a power reception coil, a power reception circuit, and a relay circuit. The power transmission coil is provided in a road. The power transmission circuit supplies electric power to the power transmission coil. The power reception coil is provided in a vehicle. The power reception circuit is connected to the power reception coil. The relay circuit transfers electric power between the power transmission coil and the power reception coil in a contactless manner.

According to an embodiment, a power supply system for an electric motor car includes a first terminal, a second terminal, and a conversion unit. The first terminal is electrically connected to one of a power storage device and an overhead wire provided within a formation of electric motor cars. The second terminal is electrically connected to a lead wire together with a plurality of electric motors within the formation, a host power supply device, an external power supply device different from the host power supply device. The conversion unit receives first electric power supplied from the plurality of electric motors and the external power supply device via the second terminal and causes a direct current (DC) voltage to be generated at the first terminal according to a regenerative operation of the conversion unit to charge the power storage device in a first operation state and receives second electric power supplied from one of the power storage device and the overhead wire via the first terminal, converts a part of the second electric power into third electric power according to a powered operation of the conversion unit, and outputs the third electric power from the second terminal in a second operation state, thereby converting electric power.

Techniques for injecting a vehicle into a high speed transportation system are described. A travel request is received from a user. The user is determined to be authorized to travel using the high speed transportation system, based on a profile associated with the user. An injection portal for the user to enter the transportation system is identified. One or more instructions for the user are provided, relating to the injection portal. A vehicle associated with the user is identified at the injection portal. Characteristics of the vehicle are sensed at the injection portal, including a center of gravity of the vehicle. The characteristics are determined to satisfy threshold values, and the vehicle is authorized for travel in the transportation system. A vehicle profile is generated. The vehicle profile is transmitted to a second controller associated with the transportation system. The vehicle is injected into the transportation system.

A power system is disclosed. The power system includes a first power generating unit. The first power generating unit includes a first power converting subunit and a first control unit coupled to the first power converting subunit, where the first control unit is configured to regulate a voltage of the first power generating unit. The power system further includes a second power generating unit coupled to the first power generating unit and a load, where the second power generating unit includes a second power converting subunit and a second control unit coupled to the second power converting subunit, wherein the second control unit is configured to control a current of the second power generating unit to share a quantity of electrical output current flowing through the load among the first and second power generating units.

A power system is disclosed. The power system includes a first power generating unit. The first power generating unit includes a first power converting subunit and a first control unit coupled to the first power converting subunit, where the first control unit is configured to regulate a voltage of the first power generating unit. The power system further includes a second power generating unit coupled to the first power generating unit and a load, where the second power generating unit includes a second power converting subunit and a second control unit coupled to the second power converting subunit, wherein the second control unit is configured to control a current of the second power generating unit to share a quantity of electrical output current flowing through the load among the first and second power generating units.

According to an embodiment, a power supply system for an electric motor car includes a first terminal, a second terminal, and a conversion unit. The first terminal is electrically connected to one of a power storage device and an overhead wire provided within a formation of electric motor cars. The second terminal is electrically connected to a lead wire together with a plurality of electric motors within the formation, a host power supply device, an external power supply device different from the host power supply device. The conversion unit receives first electric power supplied from the plurality of electric motors and the external power supply device via the second terminal and causes a direct current (DC) voltage to be generated at the first terminal according to a regenerative operation of the conversion unit to charge the power storage device in a first operation state and receives second electric power supplied from one of the power storage device and the overhead wire via the first terminal, converts a part of the second electric power into third electric power according to a powered operation of the conversion unit, and outputs the third electric power from the second terminal in a second operation state, thereby converting electric power.

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.

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 drive system for a vehicle includes a plurality of electric traction motors, each mechanically coupled to at least one drive wheel to generate traction. At least one traction power converter is connected on an AC voltage side to at least one electric traction motor to supply the electric traction motor with electric power. A traction control unit for controlling at least one traction power converter is provided and is designed to control the at least one traction power converter while the vehicle is moving based on electrical output alternating quantities of the at least one traction power converter. A rotational movement of the at least one drive wheel of the vehicle during standstill of the vehicle is not detected by a separate detection unit based on the output alternating quantities.

A power system is disclosed. The power system includes a first power generating unit. The first power generating unit includes a first power converting subunit and a first control unit coupled to the first power converting subunit, where the first control unit is configured to regulate a voltage of the first power generating unit. The power system further includes a second power generating unit coupled to the first power generating unit and a load, where the second power generating unit includes a second power converting subunit and a second control unit coupled to the second power converting subunit, wherein the second control unit is configured to control a current of the second power generating unit to share a quantity of electrical output current flowing through the load among the first and second power generating units.