Electrical power inverter having a phase modulated, twin-inverter, high frequency link and an energy storage module

Claim 2

An electrical power inverter apparatus, which includes a high frequency link, for converting DC power to AC power, comprising: (a) a first high frequency inverter module which produces a first AC voltage at a first output frequency; (b) a second high frequency inverter module which produces a second AC voltage at a second output frequency, which is substantially the same as said first output frequency and is out of phase with said first output voltage by a selected angular phase displacement; (c) mixing means for mixing said first and second output voltages to produce a high frequency carrier which has a selected base frequency impressed on the sidebands thereof; (d) rectifying means for rectifying said carrier; (e) filtering means for filtering the rectified carrier; (f) output inverting means for inverting the filtered carrier to produce an AC line voltage at said selected base frequency; and (g) phase modulating means for adjusting the relative angular phase displacement between the outputs of said first and second high frequency inverter modules to control the base frequency of said AC line voltage.

Claim 3

An apparatus as recited in claim 1, wherein said phase modulator means also controls the magnitude of said AC line voltage.

Claim 4

An apparatus as recited in claim 1, wherein said phase modulator means comprises: (a) a line voltage referencing means for producing a line voltage reference signal; (b) amplitude adjustment means for selectively controlling the magnitude of said line voltage reference signal; (c) output comparator means for comparing said inverter AC line voltage with said line voltage reference signal to produce a first line voltage error signal; and (d) inverter module modulating means for processing said line voltage error signal to adjust the relative, angular phase displacement between the outputs of said first and second high frequency inverter modules.

Claim 5

An apparatus as recited in claim 3, wherein said phase modulator means also controls the magnitude of said AC line voltage.

Claim 6

An apparatus as recited in claim 2, wherein said phase modulator means further comprises inverse sine operator means for reducing voltage distortion in said AC line voltage.

Claim 7

An apparatus as recited in claim 1, wherein said first and second inverter modules are configured as resonant-type inverter modules.

Claim 8

An apparatus as recited in claim 1, further comprising proportional drive means for driving power switches in said output inverter means.

Claim 9

An apparatus as recited in claim 1, further comprising an energy storage module for selectively storing and releasing a reactive, quadrature component of power that is circulated into said inverter apparatus from an electrical load, said storage module comprising: (a) electrical energy storage means for storing electrical energy; (b) storage module output means for flowing instantaneous reactive power from said load into said storage means and for flowing stored electrical power from said storage means into said load; (c) regulator switching means for selectively directing a flow of said reactive power from said load into said storage means and for selectively directing a flow of stored reactive power from said storage means into said load; (d) second comparator means for comparing said inverter line voltage with a line voltage reference signal to produce a second line voltage error signal; (e) third comparator means for comparing a storage energy level in said storage means with a storage referencing means to produce a resultant, storage error signal; (f) switching logic means responsive to said second and third comparator means for controlling said regulator switching means to direct said flow of reactive power from said load into said storage means in response to a first selected charge, set of error signals from said second and third compartor means and to direct said flow of reactive power from said storage means into said load in response to a second selected, discharge, set of error signals from said second and third comparator means.

Claim 10

An apparatus as recited in claim 6, wherein said storage module output means is comprised of said output inverter means.

Claim 13

A method as recited in claim 10, further comprising the step of adjusting the phasing of said first and second output frequencies to control the amplitude of said AC line power.

Claim 14

A method as recited in claim 10, wherein said adjusting step (g) comprises the steps of: (a) producing a line voltage reference signal; (b) selectively controlling the magnitude of said line voltage reference signal; (c) comparing said inverter AC line voltage with said line voltage reference signal to produce a first line voltage error signal; and (d) processing said line voltage error signal to adjust the relative, angular phase displacement between the outputs of said first and second AC voltages.

Claim 15

A method as recited in claim 10, further comprising the steps of: (a) storing a reactive, quadrature component of power circulated from a load means; (b) comparing said AC line voltage with a line voltage reference signal to produce a second line voltage error signal; (c) comparing a stored energy level value in said storage module with a storage reference signal to produce a resultant storage level error signal; (d) selectively directing said reactive, quadrature component of power from said storage means into said load in response to a first selected, discharge set of storage error signal and second line voltage error signal values; and (e) selectively directing reactive power from said load into said storage means in response to a second selected, charge set of storage error signal and second line voltage error signal values.