摘要:
A power converter operable to draw an input current that is in phase with an input voltage of the power converter and proportional to a voltage of the input voltage of the power converter includes a drive switch, a waveform generator, and a current shaping circuit. The drive switch is connected between an input inductor and ground and draws current through the input inductor when turned on. The current shaping circuit provides an on-time of the drive switch for a next cycle of the drive switch as a function of an input current decay time, a switching period of the waveform generator, and an output voltage of the power converter. The waveform generator is responsive to the on-time provided by the current shaping circuit for selectively turning the drive switch on and off to cycle the drive switch as a function of the received on-time.
摘要:
In relation to a three-phase power converter that is formed with three clusters, each of which is a serial body including one or a plurality of unit cells, a circuit system and control method used by the three-phase power converter to output negative-phase sequence currents are provided. In a power converter that has a delta-connected cascade multi-level converter (CMC) linked to a power supply system, the CMC being formed by delta-connecting series circuit, each of which is formed with a reactor and a cluster, the cluster being a serial body formed with one or a plurality of unit cells, a positive-phase sequence reactive current and a negative-phase sequence current caused by an unbalanced load linked to the power supply system are substantially offset by a positive-phase sequence reactive current and a negative-phase sequence current that are simultaneously output by the power converter.
摘要:
A power transfer system provides power factor conditioning of the generated power. Power is received from a local power source, converted to usable AC power, and the power factor is conditioned to a desired value. The desired value may be a power factor at or near unity, or the desired power factor may be in response to conditions of the power grid, a tariff established, and/or determinations made remotely to the local power source. Many sources and power transfer systems can be put together and controlled as a power source farm to deliver power to the grid having a specific power factor characteristic. The farm may be a grouping of multiple local customer premises. AC power can also be conditioned prior to use by an AC to DC power supply for more efficient DC power conversion.
摘要:
The present invention relates to a harmonic compensation circuit for compensating at least the third harmonic in the input current (I mains ) drawn by an LED light source (1) from a mains voltage supply (2), comprising: a signal input (21, 22) for receiving a first input signal proportional to the input voltage (V in ) of said LED light source (1) and a second input signal (V sh ) proportional to the LED current (I LED ) of said LED light source (1), a signal output (25) for outputting a compensation current (Icomp), a processing unit (24a, 24b) for comparing said second input signal (V sh ) to a reference signal (V Rb , V R7 ) and for generating said compensation current (I comp ) based on said comparison, the sum of said compensation current (I comp ) and said LED current (I LED ) being proportional to the input voltage (V in ) of said LED light source (1) and said compensation current (I comp ) being provided for minimizing at least the third harmonic in the input current (I mains ) drawn by said LED light source (1) from said mains voltage supply (2).
摘要:
A power supply to provide electrical power to one or more loads. The power supply may include a resonant air core transformer to provide an adjustable and adaptable source of power to electronic devices. The power supply may include isolated primary-side circuitry and secondary-side circuitry. The primary-side circuitry may include control circuitry that, among other things, provides drive waveforms for the primary-side switching circuitry. In embodiments configured to produce AC output, the secondary-side circuitry may also include switching circuitry. The primary-side control circuitry may provide drive waveforms for the secondary-side switching circuitry. The secondary-side circuitry may include measurement circuitry that measures the current and/or voltage of the output and provides those measurements to the control circuitry through isolation circuitry. The control circuitry may adjust the drive waveforms for the primary-side and/or secondary-side switching circuitry as a function of the measured values.
摘要:
A closed-loop control method with multi-channel feedback is described, in which a feedback variable r1, which is determined by sampling a closed-loop control variable x with a sampling frequency fA, and a further feedback variable r2, which is determined by averaging the closed-loop control variable x over a time period Ts, are each separately compared with a guide variable w. Each of the control errors e1, e1, which are determined in the process is fed to a separate controller 31, 32 which respectively forms therefrom an individual closed-loop control output variable m1, m2. Finally, a closed-loop control output variable m, formed from the individual closed-loop control output variables m1, m2, is used to adjust the closed-loop control variable x so that the closed-loop control variable x follows the guide variable w.
摘要:
The invention relates to a power supply device, particularly for an airplane, having a control unit (10) that is provided to match a current path to a voltage curve (12). An embodiment of the invention relates to a rectifier (30, 10, 34, 38, 40, 42, 44) with power factor correction (36, 34, 38, 40) in the form of a step-up converter with switchable (startup) current limitation (14).