摘要:
A transformerless photovoltaic system that may benefit from inverter topologies more suitable for ripple current cancellation techniques is provided. In one exemplary embodiment, the system may combine basic modules of straightforward inverter topologies to meet requirements for higher power applications and may comprise a bipolar photovoltaic array, and a full-bridge inverter electrically coupled to the bipolar photovoltaic array. The full bridge inverter may comprise first and second inverter legs that may be arranged to energize two phases of a grid electrically coupled to the photovoltaic system. In one exemplary embodiment, switching signals applied to switching devices in each of the first and second inverter legs may be adjusted relative to one other to reduce ripple current therein, thereby reducing the size of components used by the system.
摘要:
A pressurized fluid system provides electrical power to a load and includes a fluid motor, a generator, an energy storage device and a controller. The system supplies fluid to the fluid motor, which provides a generator with power producing a voltage used to supply power to a load and provide energy to the energy storage device. The controller selects which of various sources within the system provides fluid to the fluid motor based on the operating mode of the system. When fluid supplied to the fluid motor is discontinued, the energy storage device discharges providing power to the load.
摘要:
An optically powered drive circuit and a method for controlling a first semiconductor switch are provided. The optically powered drive circuit includes a photovoltaic cell configured to receive a first light signal from a fiber optic cable and to output a first voltage in response to the first light signal. The optically powered drive circuit further includes an energy storage device electrically coupled to the photovoltaic cell configured to store electrical energy received from the first voltage and to output a second voltage. The optically powered drive circuit further includes an electrical circuit electrically coupled to both the photovoltaic cell and the energy storage device. The electrical circuit is energized by the second voltage. The electrical circuit is configured to receive the first voltage and to output a third voltage in response to the first voltage for controlling operation of the first semiconductor switch.
摘要:
An AC ripple current reduction circuit for an AC converter having: an AC voltage source at the input; a first capacitor across which the circuit output voltage is provided; a first, main inductor in series with the first capacitor and the input; an auxiliary circuit including a second capacitor and a transformer coupled to the main inductor, the secondary of the transformer being in series with the second capacitor; and a means for enabling the flow of a time varying voltage across the first and second capacitors that has a frequency much less than the ripple frequency of the current in the main inductor.
摘要:
A high frequency, full bridge, resonant DC to DC converter provides a main DC output voltage that is regulated by adjusting the phase shift of the input power to a main input transformer and at least one additional DC output voltage that is regulated on the secondary side of the power input transformer. A main DC output voltage is regulated by a full bridge resonant switching converter with lossless switching of input power devices. At least one additional secondary winding on the transformer supplies a second DC output voltage that is regulated independently of the main DC output voltage. Two switching devices are used for each auxiliary DC output to regulate each auxiliary output voltage by adjusting the length of the on time of the pulses from the transformer's auxiliary secondary windings. Soft switching techniques are used to ensure that the switching devices turn on when the voltage across them is effectively zero.
摘要:
A bidirectional buck-boost power converter 13 including a pair of inverter modules 14, 15 disposed at an output of a machine, and an inductor Lo connected between the pair of inverter modules 14, 15. A method for controlling a voltage output of a machine starter generator having an inverter rectifier and bidirectional buck-boost converter, includes outputting a dc voltage controlled by bidirectional buck-boost pulse width modulation (PWM) switching control, when the starter generator is in a generator mode.
摘要:
A power system includes an energy harvesting device, a battery coupled to the energy harvesting device, and a circuit coupled to the energy harvesting device and the battery. The circuit is adapted to deliver power to a load by providing power generated by the energy harvesting device to the load without delivering excess power to the battery and to supplement the power generated by the energy harvesting device with power from the battery if the power generated by the energy harvesting device is insufficient to fully power the load. A method of operating the power system is also provided.
摘要:
A ripple current reduction circuit is provided that reduces the ripple current of a transformer by providing a substantially opposite or inverse ripple of an auxiliary current that can be combined with the ripple current of the transformer for cancellation or reduction of the ripple current.
摘要:
A method of operating a system having a coil includes providing a switched amplified current to the coil, and adding a second current to the switched amplified current, wherein the second current is substantially out of phase with the switched amplified current such that the coil receives current with substantially no switching frequency ripple.
摘要:
A bidirectional buck-boost power converter 13 including a pair of inverter modules 14, 15 disposed at an output of a machine, and an inductor Lo connected between the pair of inverter modules 14, 15. A method for controlling a voltage output of a machine starter generator having an inverter rectifier and bidirectional buck-boost converter, includes outputting a dc voltage controlled by bidirectional buck-boost pulse width modulation (PWM) switching control, when the starter generator is in a generator mode.