초록 ▼

An AC-DC converter for connecting an AC supply and a DC has a rectifier, and a harmonic correction circuit formed of (a) thyristor inverter legs connected at a common output point to form a Y switch, or separately at positive and negative terminals and (b) a voltage selection circuit for selecting a

An AC-DC converter for connecting an AC supply and a DC has a rectifier, and a harmonic correction circuit formed of (a) thyristor inverter legs connected at a common output point to form a Y switch, or separately at positive and negative terminals and (b) a voltage selection circuit for selecting a voltage derived from one of the positive and negative DC rails, or the AC lines, to control current shape and turn-off the thyristors. The thyristors are turned on by, and may also be turned off by, a controller. The voltage selection network may be a resonant circuit that uses ramping of the voltage at the outputs from the thyristors to turn the thyristors off or switches controlled by the controller. A converter for converting DC to AC power has an inverter bridge, a DC input line inductor on each DC rail, a generator for generating a waveshape output that has a frequency equal to the number of AC lines times the frequency of the AC supply; and a multiplexer for multiplexing the output of the generator onto the AC lines to reduce total harmonic distortion of current in the AC lines. The DC to AC converter may use the thyristor networks used for the AC to DC converter for the multiplexing function, under control of the controller. The generator may be a voltage selection network or switch network that selects a voltage source from one of the positive DC rail, the negative DC rail and a center tap on the DC rail.

대표청구항 ▼

[ The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:] [1.] A converter for converting AC power from a multi-phase AC power supply to DC power on a DC voltage rail, the multi-phase AC power supply including at least three AC power lines, th

[ The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:] [1.] A converter for converting AC power from a multi-phase AC power supply to DC power on a DC voltage rail, the multi-phase AC power supply including at least three AC power lines, the converter comprising:a rectifier bridged between the AC power supply and the DC voltage rail;an input line inductor on each AC power line connected in series between the AC power supply and the rectifier;a thyristor pair for each AC power line, each thyristor pair having a common point and an output, the common point being connected to the AC power line, each thyristor pair forming part of a link between the AC power line and a voltage source;the voltage source being selected from the group consisting of one of the other AC power lines, the DC voltage rail and a tap on the DC voltage rail; anda controller for the thyristor pair for time multiplexed control of flow of current through the thyristors to the AC power lines one at a time, to reduce harmonic content of current drawn from the AC power supply.