US 6,297,971 B1 · Phase converter

Abstract

A phase converter that converts single phase AC electric power to balanced three phase AC power. Two input terminal connected to the output of a single phase AC power source connect directly to two output terminals of the converter. The phase converter has two serially connected storage capacitors with a common connection, a charging circuit for controlled charging the storage capacitors and an output circuit for controlled discharge of the storage capacitors to provide single phase AC power to a third output terminal. The charging circuit controls input to the storage capacitor to provide a sinusoidal input current and to step up the voltage to the storage capacitors. The output circuit provides output power to the third output terminal of a predetermined phase and amplitude, relative to the other two output terminals, to result in balanced three phase AC power at the three output terminals. The phase converter provides balanced three phase output for leading power factor, lagging power factor, and resistive loads.

Claims21

Dependent claims

A phase converter for converting single phase AC power to balanced three phase AC power comprising:

an input connector connectable to a single phase AC power source and including first and second input terminals,
first, second and third output terminals for connection to a three phase load, said first output terminal being connected to said first input terminal and said second output terminal being connected to said second input terminal,
first and second capacitors each having a positive end and a negative end, said negative end of said first capacitor and said positive end of said second storage capacitor being connected together and to said input connector to provide a reference voltage level,
first circuit means, connected to said first input terminal, to said positive end of said first capacitor and to said negative end of said second capacitor, for controllably charging said first capacitor with a positive voltage and said second capacitor with a negative voltage,
second circuit means, connected to said third output terminal, to said positive end of said first capacitor and to said negative end of said second capacitor, for controllably discharging said first and second capacitors for supplying single phase AC power of a predetermined amplitude and phase, relative to the amplitude and phase of the power at said first and second output terminals, to said third output terminal, to result in balanced three phase AC power to said first, second and third output terminals.

2 more elements

A phase converter for converting single phase AC power to balanced three phase AC power comprising:

first and second input terminals connectable to a pair of input lines,
first, second and third output terminals connectable to a three phase load, with said first output terminal connecting to said first input terminal and with said second output terminal connecting to said second input terminal,
a charging circuit including a first inductor, first and second switches and first and second diodes, said first inductor having first and second ends with said first end being connected to said first input terminal, said first and second diodes each having an anode and a cathode, said first and second switches each having an input, an output and a control terminal, said anode of said first diode, said cathode of said second diode, said input of said first switch and said output of said second switch being connected to said second end of said first inductor,
first and second capacitors each having a positive end and a negative end, said positive end of said first capacitor being connected to said cathode of said first diode, said negative end of said second capacitor being connected to said anode of said second diode, and said negative end of first capacitor being connected to said positive end of said second capacitor,
an output circuit having a positive input, a negative input and an output, said positive input being connected to said positive end of said first capacitor, said negative input being connected to said negative end of said second capacitor, said output of said output circuit being connected to said third output terminal, and
a control module having a first control output connected to said control terminal of said first switch and a second control output connected to said control terminal of said second switch, whereby said control module switches said first switch on and off at a high frequency when the voltage at said first input terminal is positive to induce current flow through said first inductor to charge said first capacitor with a positive voltage and said control module switches said second switch on and off at a high frequency when the voltage at said first input terminal is negative to induce current flow through said first inductor to charge said second capacitor with a negative voltage.

3 more elements

A phase converter for converting single phase AC power to balanced three phase AC power comprising:

first and second input terminals connectable to a pair of input lines,
first, second and third output terminals connectable to a three phase load, with said first output terminal connecting directly to said first input terminal and with said second output terminal connecting directly to said second input terminal, and
a converter circuit including a charging portion, first and second capacitors each having a positive and a negative end, an output circuit connected to said third output terminal, and control electronics,
said charging portion including first and second diodes each having an anode and a cathode, a first inductor having first and second ends, and first and second transistors each having an emitter, a collector and a gate, said first end of said first inductor being connected to said first input terminal, said anode of said first diode, said cathode of said second diode, said collector of said first transistor and said emitter of said second transistor being connected to said second end of said first inductor, and said emitter of said first transistor and said collector of said second transistor being connected to said second input terminal,
said positive end of said first capacitor being connected to said cathode of said first diode, said negative end of said second capacitor being connected to said anode of said second diode, said negative end of said first capacitor and said positive end of said second capacitor being connected to said second input terminal,
said output circuit including third and fourth diodes each having an anode and a cathode, third and fourth transistors each having an emitter, a collector and a gate, and an output node, said cathode of said third diode and said collector of said third transistor being connected to said positive end of first capacitor, said anode of said fourth diode and said emitter of said fourth transistor being connected to the negative end of said second capacitor, said anode of said third diode, said cathode of said fourth diode, said emitter of said third transistor and said collector of the fourth transistor being connected to said output node, and said output node being connected to said third output terminal,
said control electronics including first, second, third and fourth outputs, said first output being connected to said gate of said first transistor, said second output being connected to said gate of said second transistor, said third output being connected to said gate of said third transistor, and said fourth output being connected to said gate of said fourth transistor.

4 more elements

A phase converter for converting single phase AC power to balanced three phase AC power comprising:

first and second input terminals connectable to a pair of input lines,
first, second and third output terminals connectable to a three phase load, with said first output terminal connecting directly to said first input terminal and with said second output terminal connecting directly to said second input terminal, and
a converter circuit including a charging portion, first and second Capacitors each having a positive and a negative end, an output circuit connected to said third output terminal, and control electronics,
said charging portion including first and second diodes each having an anode and a cathode, a first inductor having first and second ends, and first and second transistors each having an emitter, a collector and a gate, said first end of said first inductor being connected to said first input terminal, said anode of said first diode, said cathode of said second diode, said collector of said first transistor and said emitter of said second transistor being connected to said second end of said first inductor, and said emitter of said first transistor being connected to said negative end of said second capacitor and said collector of said second transistor being connected said positive end of said first capacitor,
said positive end of said first capacitor being connected to said cathode of said first diode, said negative end of said second capacitor being connected to said anode of said second diode, said negative end of said first capacitor and said positive end of said second capacitor being connected to said second input terminal,
said output circuit including third and fourth diodes each having an anode and a cathode, third and fourth transistors each having an emitter, a collector and a gate, and an output node, said cathode of said third diode and said collector of said third transistor being connected to said positive end of first capacitor, said anode of said fourth diode and said emitter of said fourth transistor being connected to the negative end of said second capacitor, said anode of said third diode, said cathode of said fourth diode, said emitter of said third transistor and said collector of the fourth transistor being connected to said output node, and said output node being connected to said third output terminal,
said control electronics including first, second, third and fourth outputs, said first output being connected to said gate of said first transistor, said second output being connected to said gate of said second transistor, said third output being connected to said gate of said third transistor, and said fourth output being connected to said gate of said fourth transistor.

4 more elements

A phase converter for converting a single phase AC power to balanced three phase AC power comprising:

first and second input terminals connectable to a pair of single phase AC power input lines,
a third input terminal connectable to a neutral line,
first, second and third output terminals connectable to a three phase load, with said first output terminal connecting directly to said first input terminal and with said second output terminal connecting directly to said second input terminal, and
a converter circuit including a charging portion, first and second capacitors each having a positive and a negative end, an output circuit connected to said third output terminal, and control electronics,
said charging portion including first, second, third, fourth, fifth and sixth diodes each having an anode and a cathode, first and second inductors each having a first and second end, and first and second transistors each having an emitter, a collector and a gate,
said anode of said third diode being connected to said first input terminal, said anode of said fourth diode being connected to said second input terminal, said cathode of said fifth diode being connected to said first input terminal, and said cathode of said sixth diode being connected to said second input terminal,
said first end of said first inductor being connected to said cathodes of said third and fourth diodes and said first end of said second inductor being connected to said anodes of said fifth and sixth diodes,
said second end of said first inductor being connected to said anode of said first diode and said collector of said first transistor, and said second end of said second inductor being connected to said cathode of said second diode and said emitter of said second transistor, said gates of said first and second transistors being connected to said control electronics, and said emitter of said first transistor and said collector of said second transistor being connected to said third input terminal,
said positive end of said first capacitor connecting to said cathode of said first diode, said negative end of said second capacitor connecting to said anode of said second diode, and said negative end of said first storage capacitor and said positive end of said second storage capacitor connecting to said third input terminal,
said output circuit including seventh, eighth, ninth and tenth diodes each having an anode and a cathode, third, fourth, fifth, sixth transistors each having an emitter, a collector and a gate, a third inductor, third and fourth capacitors and an output node, said cathode of said seventh diode and said collector of said third transistor being connected to said positive end of said first capacitor, said anode of said eighth diode and said emitter of said fourth transistor being connected to said negative end of said second capacitor, said anode of said seventh diode, said cathode of said eighth diode, said emitter of said third transistor and said collector of said fourth transistor each being connected to said output node,
said cathode of said ninth diode and said anode of said tenth diode being connected to said output node, said emitter of said fifth transistor being connected to said anode of said ninth diode, said collector of said sixth transistor being connected to said cathode of said tenth diode, and said collector of said fifth transistor and said emitter of said sixth transistor each being connected to said third input terminal, said gates of said third, fourth, fifth and sixth transistors being connected to said control electronics, and
said third inductor connecting said output node to said third output terminal, said third capacitor being connected between said first output terminal and said third output terminal, and said fourth capacitor being connected between said second output terminal and said third output terminal.

9 more elements

Dependencies are inferred from the claim text.

Phase converter

Life of this patent

Phase converter

Life of this patent

Abstract

Claims21