57 results about "Current shaping" patented technology

A single-stage input-current-shaping (S<2>ICS) flyback converter achieves substantially reduced conduction losses in the primary side of the S<2>ICS flyback converter by connecting a bypass diode between the positive terminal of a full-bridge rectifier and the positive terminal of an energy-storage capacitor. An effective current interleaving between an energy-storage inductor and the bypass diode is thus obtained in the S<2>ICS flyback converter around the peak of the rectified line voltage, resulting in a significantly reduced input-current ripple and reduced current stress on the switch. Further, by rearranging the rectifiers in the ICS part of the S<2>ICS flyback converter in such a way that the energy-storage capacitor and the ICS inductor are connected to the ac line voltage through only two rectifiers, one diode forward-voltage drop is eliminated, which results in a substantially reduced conduction loss in the primary-side rectifiers.

An AC/DC power converter has an AC input and a DC output, with an input rectifier circuit coupled to the AC input. The input rectifier circuit includes a passive half-bridge rectifier circuit functional to provide passive rectification of an AC input power sign and at least one current shaper circuit. The current shaper circuit includes an input inductor coupled between the AC input and a switch node in the input active rectifier circuit. The input current shaper circuit is functional to shape an AC input current signal associated with an AC input power signal to a substantially sinusoidal current signal. A bulk capacitor circuit is coupled to the input active rectifier circuit. A DC/AC converter circuit is coupled to the bulk capacitor circuit. A resonant circuit is coupled to the DC/AC converter circuit and an output rectifier circuit may be coupled between the resonant circuit and the DC output.

The invention discloses an LLC primary side constant current control device and a compensation current signal extraction method. The control device receives voltage signals at two ends of a transformer winding of a converter and sampled primary side resonance current signals, extracts first resonance interval current signals from the primary side current shaping signals according to a time interval, shapes the first resonance interval current signals according to the voltage polarity of the transformer winding, adds bias voltage and obtains first resonance interval average current signals after average processing. The method includes the steps of taking the initial and end current values of the shaped and biased primary side current shaping signal in the first resonance interval, summing the initial and end current values to solve the mid-value and obtain a compensation current signal, and subtracting the compensation current signal from the average current signal in the first resonance interval to obtain a signal reflecting the average value of the output current. The invention can omit an optical coupler and a secondary side feedback circuit, and effectively improves the stability of the circuit. In addition, the primary side constant current control device can be further integrated into a single chip, and the circuit cost is further reduced.

A converter topology that eliminates reverse recovery losses in its output rectifying semiconductor devices employs an AC injection voltage source in series with a power transformer primary winding. Input semiconductor switches in the converter's primary circuit are controlled to provide in the power transformer secondary a voltage across the winding or windings in a first direction forward biasing one of the output rectifying devices followed by a lower level reverse biasing voltage produced by the injection voltage. This lower level voltage across the secondary turns off the previously conducting rectifier device and drives carriers out of its semiconductor junction or junctions to eliminate reverse recovery losses occurring when the secondary applies a higher level reverse bias across the non-conducting rectifier device. The injection voltage source can be a transformer in addition to the power transformer having a primary winding in series with the primary winding of the power transformer and a secondary winding connected to ground through a capacitor. In addition to preventing reverse recovery losses in the rectifying devices in the secondary, the injection voltage transformer also injects an AC triangular waveform current into the current in the converter primary input circuit to the junction of the semiconductor switches where they are connected in a bridge circuit supplying the power transformer primary. By this, the injection voltage source assures zero voltage switching of the semiconductor switches even at light loads.

Disclosed is a PFC (power factor correction) device for shaping an input current of a power converter. The device includes means for receiving a rectified input voltage derived from an AC input voltage; load determining means for determining a load value L which represents the power drawn by a load supplied by the power converter; current shaping means for shaping the input current of the power converter to follow a reference waveform; and control means for controlling the current shaping means to operate over a conduction interval α during each positive and negative half cycle of the AC input voltage. The duration of the conduction interval is controlled in accordance with the load value L. The current shaping means may shape the input current to follow the reference waveform which crosses zero at phase angles which substantially correspond to the start and end of the conduction interval.

A current shaping phase leg bus bar for power electronics systems includes a first terminal connector, a second terminal connector, insulated from the first terminal connector, and a third terminal connector, insulated from the first and second terminal connectors. At least one of the terminal connectors is a current shaping terminal connector that includes one or more layers having a plurality of pre-defined locations for electrical connections, said plurality of pre-defined locations including one or more first locations and a plurality of second locations, and includes one or more gaps within or among its one or more layers, to provide substantially balanced conductive pathways among its one or more first locations and its plurality of second locations.

A bus bar includes a load terminal connector comprising a conductive plate that extends from a first edge to an opposite second edge and extends from a third edge to an opposite fourth edge. The third and fourth edges extend from the first edge to the second edge. The plate includes a window opening located between the first and second edges and between the third and fourth edges. The plate also includes a slot extending into the plate from the first edge to the window opening. The plate includes first and second sets of openings configured to receive connections with first and second power terminals of switch packages. The first set of openings and the second set of openings are located on opposite sides of the slot.

The invention discloses a non-contact type three-phase current detection system. The system comprises an induced loop current sampling unit, a magnetic induction sampling unit, a current shaping unit,a signal processing unit and a current monitoring unit; the magnetic induction sampling unit is a magnetic induction chip and is matched with the current sampling unit, and the magnetic induction sampling unit is used for inducing the three-phase current acquired by the induced loop current sampling unit; the current shaping unit is used for shaping the three-phase current sensed by the magneticinduction sampling unit; the signal processing unit is used for performing analog-to-digital conversion and filtering processing on the shaped three-phase current; and the current monitoring unit is used for verifying the three-phase current processed by the signal processing unit according to a preset current error. The non-contact three-phase current detection system provided by the invention not only is simpler in structure, but also can realize accurate and stable sampling and verification diagnosis of the three-phase current, and is better in performance.