70 results about "Active front end" patented technology

A photovoltaic (PV) integrated variable frequency drive system having a variable frequency drive and an energy source. The variable frequency drive having a back end inverter, a DC bus electrically connected to the back end inverter, and an active front end electrically connected to the DC bus to facilitate bi-directional power flow to and from a power grid. The energy source being electrically connected to the DC bus.

A communication system includes a conversion module configured to convert a signal between a radio frequency baseband (RF-BB) and an intermediate frequency (IF). At least one RF front-end module converts the signal between the IF and a radio frequency (RF). The RF front-end module is configured as an RF phased array and includes a coaxial interconnect configured to connect the conversion module with the RF front-end module. The signal is transmitted between the conversion module and the RF-front end module via the coaxial interconnect. At least one RF front-end module includes an active front-end (AFE) configured to allow the signal to be transmitted via the coaxial interconnect while minimizing any deterioration of the signal.

A dragline excavating machine includes a gearless direct drive AC drive motor for driving each of the hoist and the drag drums in the system. The gearless AC motor is driven using a digital system which receives AC power from the utility system rectifies the power using active front end circuits, and converts the resultant DC to a frequency controlled AC using an inverter circuit. The resultant AC signal is employed to drive the gearless AC motor, resulting in reduced harmonic distortion, unity or leading power factor, and increased efficiency, reduced operating costs, and reduced mean time between failure.

An adjustable frequency drive includes a base having a first portion and a second portion, and an active front end converter disposed on the base. The converter includes an input, an output, and a plurality of first electronic switches electrically connected between the input and the output. An inverter is disposed on the base and includes an input electrically connected to the output of the active front end converter, an output, a plurality of capacitors disposed on the first portion of the base and electrically connected to the input of the inverter, a plurality of second electronic switches disposed on the second portion of the base and electrically connected between the input and the output of the inverter, and a heat pipe assembly. The inverter is structured to provide a single, three-phase output structure.

This application describes a dynamically tuned front end module using a modal antenna approach for improved communication system performance. The front end module consists of power amplifiers, filters, switches and antennas along with tuning circuits integrated and controlled to provide an optimized system for RF transmission. Dynamic tuning provides the ability to maintain optimized system performance for a wide variety of use cases and environments that the wireless device is operated in. Several transmission modes are accessed in an algorithm to optimize the performance of multiple wireless devices in a cellular system, to include a power conservation mode, emergency transmission mode, and cell capacity optimization mode. Dynamic adjustment of correlation and isolation between multiple antennas is a benefit provided by this front end topology.

A power converter includes an active front end (AFE) that is coupled by a dc link stage to a plurality of H-bridge inverters. One or more multi-phase electro-magnetic energy conversion devices, such as transformers or electric machines, with open windings that are connected to only the AFE or only the H-bridge inverters or to both the AFE and H-bridge inverters, provide a regenerative or partial regenerative power converter.

This application describes a dynamically tuned front end module using a modal antenna approach for improved communication system performance. The front end module consists of power amplifiers, filters, switches and antennas along with tuning circuits integrated and controlled to provide an optimized system for RF transmission. Dynamic tuning provides the ability to maintain optimized system performance for a wide variety of use cases and environments that the wireless device is operated in. Several transmission modes are accessed in an algorithm to optimize the performance of multiple wireless devices in a cellular system, to include a power conservation mode, emergency transmission mode, and cell capacity optimization mode. Dynamic adjustment of correlation and isolation between multiple antennas is a benefit provided by this front end topology.

Embodiments herein relate to a rectifier to supply a DC bus that in turn supplies voltage to a converter that drives a motor and configuring the rectifier to minimize or eliminate common mode voltage between the DC bus and the AC source. In this way, the embodiments herein relate to timing and switching a power from the rectifier to the DC bus.

The present invention provides a power distribution system such as a marine power distribution and propulsion system (20). The system includes an ac busbar (2) and a plurality of active front end (AFE) power converters (4, 22). Each AFE power converter (4, 22) includes a first active rectifier / inverter (6) connected to the busbar (2) and a second active rectifier / inverter (8) connected to an electrical load such as an electric propulsion motor (M1...M4). Power sources (PS1...PS3) are connected to the dc link (24) of the AFE power converters (22) and can be operated under the control of a power management controller or power management system (PMS).

The invention relates to a load test device for a large-power frequency converter adopting a front active end. The main technical characteristics are that: the load test device comprises a frequency convertor, a reactor and a direct-current power supply; the reactor is connected between a rectification unit and an inversion unit of the frequency convertor; the front active end is adopted by the rectification unit; and the direct-current power supply is connected with the middle direct-current side of the frequency convertor to ensure that the rectification unit, the middle direct current side, the inversion unit, and the reactor form a power loop. The load test device has reasonable design, and can be implemented by only one reactor with small capacity, and an externally connected power supply with small capacity; and other power consumption except loss on a power device and a line is avoided in the whole test process, and large-power current can pass through the frequency convertor only taking a small amount of energy from a power grid, so that the function that a power grid with small capacity is subjected to load test of the large-power frequency converter can be realized, and the load test device has the advantages of simple structure, accurate test result, few auxiliary appliance and the like and is easy to implement.

Apparatus and methods are provided for detecting degradation of delta-connected filter capacitors in an active front end (AFE) power converter, in which delta circuit capacitor leg currents are calculated based on measured branch circuit currents, and filter capacitor impedance values are computed based on the calculated leg currents as well as measured line-to-line voltages and corresponding phase angles for comparison with one or more thresholds to selectively detect degradation of the filter capacitors. Further apparatus and methods are provided for detecting degradation of Y-connected filter capacitors by computation of fundamental frequency RMS impedance values as ratios of RMS capacitor voltages and RMS circuit branch currents, and comparison of the calculated RMS impedance values with one or more thresholds.

A photovoltaic (PV) integrated variable frequency drive system having a variable frequency drive and an energy source. The variable frequency drive having a back end inverter, a DC bus electrically connected to the back end inverter, and an active front end electrically connected to the DC bus to facilitate bi-directional power flow to and from a power grid. The energy source being electrically connected to the DC bus.

Methods and systems are disclosed for detecting capacitor degradation in an input filter of an active front end power conversion system in which voltage and current sensing is performed to determine sequence component impedance asymmetry to detect filter capacitor degradation according to the value of an off-axis admittance matrix component for Delta or Y-connected filter capacitor banks without sensitivity to voltage unbalance, and with the capability to identify particular degraded capacitor locations based on individual impedance values.

The invention discloses an AC / DC (alternating current / direct current) convertor implementation method based on an asymmetrical multi-level synthesis technology, belongs to an AC / DC conversion and control technology related to the electrical technology, and aims to research develop an AC / DC convertor which has low harmonic wave and high quality and is suitable for application requirements for various capacities. The AC / DC convertor implementation method is characterized in that the traditional mode that current of a 12-pulse-wave AC / DC convertor is symmetrically distributed to two three-phase bridge inverters for conversion is replaced with the novel method that the current is asymmetrically distributed to two three-phase bridge inverters, direct current is distributed to the two three-phase bridge inverters according to a given conversion rule, so that three-phase alternating current of an incoming line of the convertor is sine-wave current, then an equal-increment step-shaped triangular wave current waveform is adopted for approximate substitution of ideal transformation, and the AC / DC convertor implementation method based on the asymmetrical multi-level synthesis technology has the characteristics of low harmonic wave, thyristor controllability, lead-lag continuous adjustment of a power factor, high combined efficiency of a system and suitability to application requirements for various capacities and can be applied to direct-current power sources with various capacities and active front-end converters with various applications.

Certain exemplary embodiments comprise a system comprising a plurality of Active Front End units adapted to be electrically coupled to a direct current (DC) bus. Each of the plurality of Active Front End units can be adapted to be electrically coupled to a separate winding of a transformer of a plurality of transformers. Each of the plurality of Active Front End units can be adapted to convert alternating current (AC) voltage to a DC voltage. Each of the plurality of Active Front End units can be adapted to supply the DC voltage to the DC bus. The DC bus can be adapted to be electrically coupled to a plurality of inverters.