Negative impedance converter

About: Negative impedance converter is a research topic. Over the lifetime, 5801 publications have been published within this topic receiving 87636 citations.

Integrated circuit for generating a plurality of direct current (DC) output voltages

Abstract: A cascaded DC-DC converter architecture has an upstream converter stage and a downstream converter stage, which derives its input voltage from the upstream stage. Cascading the two converter stages enables functionality of control and monitoring (including soft start and overcurrent detection) circuitry of the upstream stage to be used for the downstream stage, to reduce chip area, cost, and complexity. A voltage window regulator in the downstream converter ensures that, during shutdown, its output voltage will be maintained within a prescribed window of its regulated output voltage, so that no soft start delay is needed when the second converter stage is turned back on.

Distance protection solution for a converter controlled microgrid

Abstract: Distance relay response in the presence of a converter dominated microgrid system has been analyzed in this paper. Converter structure and control mechanism are presented and a new method is proposed to limit fault currents in faulted phase/phases by reducing the converter output voltage. A method of analyzing unsymmetrical supply voltage using symmetrical component theory is proposed, where it has been assumed that voltage source converter (VSC) supplies unbalanced voltages in the event of a fault. Performance of distance relays with Mho characteristics are evaluated in a radial distribution feeder for both phase and earth unbalanced faults. The results are validated through PSCAD simulation and MATLAB calculations

The Zero Voltage Switching Partial Series Resonant Converter

Abstract: A new high-frequency dc to dc converter, suitable for application in the kilowatt range, is presented. The topology is based on a half bridge series resonant converter, i.e., having only two switches. Resonance occurs only for a part of each switching cycle, and a discrete energy pulse is transferred to the load every half cycle, rendering a variable frequency controller for controlling the output power. The converter features zero-voltage turn-on, and snubbed turn-off at reduced current for the switching devices, and zero current commutation of the rectifier diodes, making it suitable for IGBT switches operating at a switching frequency higher than 20 kHz. The efficiency of the converter is very high under full load and low load conditions, while the dynamic output voltage range is two times larger than that of the conventional half bridge Series Resonant Converter.

DC-to-DC converter with transient suppression

Abstract: A DC-to-DC converter includes: a first circuit to sense when the converter output voltage occurs outside a substantially pre-determined range, and a second circuit to adjust the converter load current, based at least in part, upon a signal provided by the first circuit. Alternatively, a circuit to suppress voltage transients for use in a DC-to-DC converter having a primary inductor includes: another circuit inductance lower than the inductance of the primary inductor. The another circuit inductance is coupled in the circuit to be activated when the load voltage of the DC-to-DC converter occurs outside a substantially predetermined range. The another circuit inductance is further coupled in the circuit so that it has the capability to modify the load current during activation.