AC to DC power conversion system

A method for converting alternating current into direct current comprising the steps of:

• a) determining the phase and voltage of one or more AC inputs;
• b) controlling a switching matrix coupled to said AC inputs to generate a DC output;
• c) determining the energy required by said DC output by subtracting said DC output from a DC reference voltage and determining an appropriate increase or decrease of said DC output to maintain a desired DC output;
• d) evaluating the phase of each of said AC inputs to determine which of said AC inputs can best maintain said desired DC output;
• e) comparing the voltage of each of said AC inputs with a voltage threshold level to prevent operation of said power conversion circuit if said AC input is outside predetermined threshold limits;
• and
• f) selectively electrically connecting said determined AC input to said DC output by energizing appropriate switching elements within said switching matrix.

A power conversion circuit comprising:

• a) at least two AC input lines electrically connected to an external, alternating current (AC) power source;
• b) at least one pair of DC output lines;
• c) an impedance means having an input and an output, having said input electrically connected to said AC input lines;
• d) switching means having an input electrically connected to said output of said impedance, and having an output and a control input;
• e) filter means having an input electrically connected to said output of said switching means and an output electrically connected to said DC output lines, for electrically filtering out undesired electronic signal components;
• and
• f) control circuit means electrically connected to said control input of said switching means for selectively enabling said switching means, said switching means selectively electrically connecting said output of said impedance to said input of said filter means, said control circuit means further including
• a voltage feedback circuit coupled to said DC output lines,
• a voltage and phase detection means electrically connected to said AC input lines, said voltage detection means for comparing the voltage of each of said AC inputs with a voltage threshold level to prevent operation of said power conversion circuit if said AC input is outside predetermined threshold limits,
• a first signal processing means coupled to said voltage and phase detection means and said voltage feedback circuit for determining whether more or less energy should be supplied to said DC output lines, and
• a second signal processing means electrically connected to said first signal processing means and electrically connected to said AC input lines for determining which AC input lines should be electrically connected through said switching means to said DC output lines.

A power conversion system for operating in conjunction with a line frequency waveform, the system comprising:

• a) an Alternating Current (AC) power input for accepting AC inputs having a waveform at a given power level;
• b) a Direct Current (DC) output for providing a DC output;
• c) an input filter circuit for rectifying the AC inputs and having an output;
• d) a high frequency switch circuit coupled to the output of the filter network for producing said DC output;
• e) a switch control circuit for controlling the operation of the switch circuit;
• f) means for determining the energy required by said DC output;
• g) means for determining an appropriate increase or decrease of said DC output to maintain a desired DC output;
• h) means for evaluating the phase of said AC inputs to determine which of said AC inputs can best maintain said desired DC output;
• i) means for comparing the voltage of said AC inputs with a voltage threshold level to prevent operation of said power conversion circuit if said AC input is outside predetermined threshold limits:
• and
• j) means for ensuring that a vector representing the combined real and imaginary portions of a current load is synchronized with a vector representing the real and imaginary portions of the voltage applied to said AC power input to provide maximum power transfer and minimize switching losses.

A method for converting an Alternating Current (AC) power input having at least two phases into a Direct Current (DC) output comprising;

• a) filtering the AC power input by a rectifier circuit;
• b) coupling an output from said rectifier circuit to a high frequency switch circuit;
• c) controlling the operation of the switch circuit to generate said DC output;
• d) determining the energy required by said DC output;
• e) determining an appropriate increase or decrease of said DC output to maintain a desired DC output;
• f) comparing a voltage level of said AC inputs with a voltage threshold level to prevent conversion of said AC power input if said voltage level is outside predetermined threshold limits;
• g) evaluating the phase of each of said AC inputs to determine which of said AC inputs can best maintain said desired DC output;
• and
• h) synchronizing a vector representing the combined real and imaginary portions of a current load of said desired DC output with a vector representing the real and imaginary portions of the voltage applied to said AC power input to provide maximum power transfer and minimize switching losses.