109results about "Dc circuit with intermediate ac" patented technology

A power pick-up for an Inductively Coupled Power Transfer (ICPT) system is provided having a resonant pick up circuit. The natural frequency of the pick-up circuit may be varied by controlling the conductance or capacitance of a variable reactive in the resonant circuit. The load being supplied by the pick-up circuit is sensed, and the effective capacitance or inductance of the variable reactive component is controlled to vary the natural resonant frequency of the pick-up circuit to thereby control the power flow into the pick-up to satisfy the power required by the load.

A resonant converter is provided which may be used for supplying power to the primary conductive path of an inductively coupled power transfer (ICPT) system. The converter includes a variable reactive element in the resonant circuit which may be controlled to vary the effective inductance or capacitance of the reactive element. The frequency of the converter is stabilised to a nominal value by sensing the frequency of the converter resonant circuit, comparing the sensed frequency with a nominal frequency and varying the effective inductance or capacitance of the variable reactive element to adjust the converter frequency toward the nominal frequency.

To provide a wireless power receiving device, and a wireless power transmission device capable of improving the reliability of a protection circuit while preventing breakage of a circuit element upon occurrence of any abnormality, such as overvoltage or overcurrent. A wireless power receiving device includes a power receiving coil; a rectifier unit that performs full-wave rectification of the power received by the power receiving coil and supplies the power to a load; power-receiving-side detecting unit that detects an output voltage value or an output current value from the rectifier unit; and switching unit that short-circuits one of two current paths through the rectifier unit if the value detected by the power-receiving-side detecting unit exceeds a predetermined reference value.

Methods and circuitry for combining the outputs of multiphase power converters which greatly improves the transient response of the power conversion system are presented in a variety of embodiments. Transformers may be used to accomplish the combining function, and with properly phased and connected windings it is possible to achieve a great reduction in output ripple current and a simultaneous reduction in transistor ripple current, which give the designer freedom to reduce the value of the system output inductor, improving transient response.

The disclosed DC-DC conversion system for implementing isolated high-frequency switch comprises: a primary circuit of transformer to output square-wave voltage to a transformer, a PWM controller to output PWM control signal and drive circuits, and a secondary circuit of transformer including a BUCK conversion circuit to receive PWM control signal from the PWM controller and take BUCK conversion to the square wave voltage and feedback the load signal to the controller. This invention can improve the dynamic regulation response for entire circuit.

Disclosed is a motor-driven vehicle including: a first and second battery; a voltage converter that includes a plurality of switching elements configured to perform voltage conversion between an electric power output path and the first and second battery, and to switch the connection of the first battery and the second battery between an in-series connection and an in-parallel connection; a motor-generator; and a control device configured to turn on and off the switching elements, in which the control device switches connection to either of connection between the electric power output path and both the first battery and the second battery, and connection between the first battery and the second battery based on the switching element temperature, and the operating point of the motor-generator.

A direct current power system according to one non-limiting embodiment includes a direct current power source operable to distribute a direct current voltage throughout at least one structure, and at least one controller operable to selectively couple a direct current load to the direct current voltage in response to a wireless signal from an energy-harvesting switch.

An auxiliary power supply equipment for a high voltage installation includes a power source at ground potential, a load circuit at high potential, and a transmission link for coupling the power source to the load circuit. The power source includes a high frequency voltage generator, and the transmission link comprises a first and a second current path. Each path is closed by capacitive coupling to provide insulation between the ground potential and the high potential, and each current path has a reactive compensation means for series compensation of reactive power generated by the capacitive coupling.

A switching type power converter circuit includes a step-down converter circuit, a DC/AC converter circuit coupled to the step-down converter circuit, and a rectifier circuit coupled to the DC/AC converter circuit. In one embodiment, the DC/AC converter operates with near 50% duty cycle and with substantially zero-voltage, substantially minimum current switching in a resonant mode. An auxiliary step down converter may be added. An AC/DC converter front end with a full-wave bridge, an RF filter, and a power factor correction circuit may also be added.

A control and monitoring system power supply is described that receives a single power input and distributes power to two distinct segments of a control and monitoring system network. The power supply includes a single power input configured to receive AC from a power source and at least partially convert the AC power to an operable voltage for a network device. Further, the power supply includes dual power output drivers that share power from the single power input and distribute the power to distinct network cable segments. Each of the dual power output drivers is separate and common grounded with respect to the other.

The invention discloses a direct-current solid-state transformer with the fault ride-through capability and a control method thereof. The direct-current solid-state transformer is composed of a filterinductor, a full-bridge sub module, N-1 half-bridge sub modules, and N DC-DC isolated converters. The bridge sub modules are in cascaded connection and then the cascaded connection unit is connectedin series with the filter inductor to connect an intermediate-voltage direct-current grid. The output terminal of each bridge sub module is connected with a direct-current input terminal of each DC-DCisolated converter; and direct-current output terminals of all DC-DC isolated converters are connected in parallel and then are connected with a low-voltage direct-current grid. When a short-circuitfault occurs at the intermediate-voltage direct-current grid, if the voltage of the intermediate-voltage direct-current grid with the fault is higher than a preset threshold, the duty ratio of all thebridge sub modules of the direct-current solid-state transformer are adjusted to realize a fault ride-through effect; and if the direct-current voltage is lower than or equal to the preset threshold,the half-bridge sub modules and the connected DC-DC isolated converters are turned off and only the full-bridge sub module and the connected DC-DC isolated converters work to realize the fault ride-through effect.

The invention discloses a direct current power supply system for a data center. The direct current power supply system comprises a first alternating-current power grid (1), a solid-state transformer (3), a set of UPS system (9), a plurality of IT loads (7), a plurality of fan loads (8) and a direct current power supply system; normally, the power supply for the IT loads (7) and fan loads (8) is performed by the first alternating-current power grid (1) through high-tension direct current bus (4), and charged by a energy storage battery (12); in the event of power failure due to the faults of the first alternating-current power grid (1) or the high-tension direct current bus (4), uninterruptible power supply for the IT loads (7) and fan loads (8) is realized by the energy storage battery (12). Compared with the prior art, the direct current power supply system for the data center greatly reduces the volume of a transformer, the volume of a distribution wire and cost, is convenient for flexible access of renewable energy sources, and further improves the utilization rate of electrical energy; the system configuration is flexible, so it is beneficial to great reduction of the battery charge and discharge loss, and power supply system efficiency of the data center is improved.

A submersible power system includes at least one DC power source and at least one submersible power distribution system electrically coupled to the at least one DC power source. The at least one submersible power distribution system includes at least one receptacle configured to be exposed to an underwater environment. The at least one submersible power distribution system also includes a plurality of power conversion modules removably positioned within the at least one receptacle. Each power conversion module of the plurality of power conversion modules includes an enclosure configured to be exposed to the underwater environment. The at least one submersible power distribution system further includes at least one switchyard module selectably coupled to and uncoupled from the plurality of power conversion modules. The at least one switchyard module includes a plurality of switches configured to electrically bypass and isolate each power conversion module from the DC power source.

The invention discloses a power supply system for a direct-current remote-power-supply alternating current local side terminal on an expressway and a method. The method comprises the following steps: dividing an area to be supplied with power on the expressway into a plurality of power supply units according to a preset distance; arranging at least one alternating current local side terminal in each of the power supply units, wherein the alternating current local side terminal comprises a voltage converting module with an alternating current input end and a direct current output end; the alternating current input end is connected with an alternating current power frequency or an intermediate frequency voltage power supply; at least one direct current voltage is outputted from the direct current output end; all the remote terminals on all the loading positions to be supplied with power in the power supply units are successively connected with each other through transmission cables, started from the alternating current local side terminal; the remote terminals are used for converting the received direct current voltage into the voltages required by load and supplying the load with power. The power supply system provided by the invention has the beneficial effects that the operation maintenance cost is lower than the cost of other power supply mode, and principally, the maintenance is not required if the power supply is not damaged.

The present invention provides a method to ensure that distributed resources of a power distribution system remain connected to the circuitry of the power distribution system when a fault occurs at a distributed resource node to assist in identifying the location of the fault by continuing to inject current from the distributed resources into the distribution system. The system contains multiple power electronics based converters which convert the local direct current (DC) distributed sources (DRs) to the alternating current (AC) of the grid. The converters also provide the capability of limiting the current in the system when a fault occurs. The converters also protect the power distribution system equipment against high fault currents.