US 5,933,339 A · Modular static power converter connected in a multi-level, multi-phase, multi-circuit configuration

Abstract

In the particular embodiments described, an unlimited voltage static power converter includes an array of multi-level phase drivers consisting of a plurality of H-bridge power modules connected in series. The midpoint node of the series-connected power semiconductors is connected to corresponding midpoint nodes in adjacent H-bridges to achieve a desired high output voltage using available power switch ratings. A three-dimensional multi-level, multi-phase, multi-circuit array of H-bridges permits the use of the static power converter for high power applications, while providing a high degree of power quality. The power semiconductor switches are operated in accordance with a two-dimensional interleaved pulse width modulation algorithm which produces a waveform with a switching frequency that can be more than an order of magnitude higher than the switching frequency of a single power switch. PWM complementary triangle carrier waves are used for individual PWM control of each H-bridge in each multi-level phase driver, resulting in a two-dimensional interleaved control algorithm. Injection of harmonic or non-harmonic content into the PWM reference waveform further reduces harmonic and non-harmonic content of the output voltage waveforms. Part-load efficiency is increased using unique load partitioning methods, five of which are described herein.

Claims46

Dependent claims

A static power converter comprising:

at least one isolated DC power source;
an array of power converter modules connected in a multi-level, multi-phase, multi-circuit configuration wherein:
(a) each phase comprises a plurality of circuits and each circuit comprises a parallel configuration of multi-level phase drivers;
and
(b) each multi-level phase driver comprises a plurality of H-bridges connected in series;
and each H-bridge comprises two pairs of power semiconductors, each pair connected in series between positive and negative terminals of an isolated DC power source, a midpoint node of the series-connected power semiconductors being connected to corresponding midpoint nodes in adjacent H-bridges, thereby permitting a maximum output voltage to be produced which is equal to the sum of the DC voltages applied to the bridges;
and
control means for controlling the power semiconductors which interleaves gate signals applied to the H-bridges of the array of multi-level phase drivers;
the interleaving being arranged according to an algorithm whereby normal and complementary triangle carrier waveforms of a desired switching frequency are established for each level of a multi-level phase driver, and are phase shifted with respect to each other by an angle .alpha..sub.lvl =360.degree./l, where l is the number of levels of the multi-level phase driver and whereby normal and complementary triangle carrier waveforms of the desired switching frequency are established for the multi-level phase drivers of the multiple circuits such that the carrier waveform for each circuit of a level of interest is phase-shifted with respect to the corresponding circuits of the same level by the angle .alpha..sub.ckt =.alpha..sub.lvl /2k where k is the number of static power converter circuits.

6 more elements

A static power converter comprising:

at least one isolated DC power source;
an array of power converter modules connected in a multi-level multi-phase, multi-circuit configuration wherein:
(a) each phase comprises a plurality of circuits and each circuit comprises a parallel configuration of multi-level phase drivers;
and
(b) each multi-level phase driver comprises a plurality of H-bridges connected in series;
and each H-bridge comprises two pairs of power semiconductors, each pair connected in series between positive and negative terminals of an isolated DC power source, a midpoint node of the scries-connected power semiconductors being connected to corresponding midpoint nodes in adjacent H-bridges, thereby permitting a maximum output voltage to be produced which is equal to the sum of the DC voltages applied to the bridges;
and
control means for controlling the power semiconductors wherein the interleaving is arranged according to an algorithm whereby normal and complementary triangle carrier waveforms of a desired switching frequency are established for each level of a multi-level phase driver, and are phase shifted with respect to each other by an angle .alpha..sub.lvl =360.degree./2l, where l is the number of levels of the multi-level phase driver and normal and complementary triangle carrier waveforms of the desired switching frequency are established for the multi-level phase drivers of the multiple circuits such that the carrier waveform of each circuit of the level of interest is phase-shifted with respect to the corresponding circuits of the same level by the angle .alpha..sub.ckt =.alpha..sub.lvl /k where k is the number of static power converter circuits.

5 more elements

A static power converter comprising:

(a) at least one isolated DC power source;
(b) an array of power converter modules connected in a multi-level, multi-phase, multi-circuit configuration wherein each phase comprises a plurality of circuits and each circuit comprises a parallel configuration of multi-level phase drivers;
and
(c) each multi-level phase driver comprises a plurality of dual H-bridges connected in series and each dual H-bridge comprises four pairs of power semiconductors, each pair connected in series between positive and negative terminals of the same one of the plurality of isolated DC power sources;
(d) an interphase transformer connecting the midpoint nodes of two pairs of semiconductors in each dual H-bridge, the midpoint nodes of the remaining two pairs of semiconductors in each dual H-bridge being available for connection to an adjacent dual H-bridge and the output terminals of each interphase transformer being connected to an adjacent dual H-bridge;
and
(e) control means for controlling the power semiconductors wherein the control means supplies carrier waveforms in the form of a triangle wave and its complement to each H-bridge and the carrier waveforms within each multi-level phase driver are evenly distributed throughout a PWM period.

4 more elements

Dependencies are inferred from the claim text.

Modular static power converter connected in a multi-level, multi-phase, multi-circuit configuration

Life of this patent

Modular static power converter connected in a multi-level, multi-phase, multi-circuit configuration

Life of this patent

Abstract

Claims46