Poly-phase inverter with independent phase control

• US 9,812,949 B2
• Filed: 10/10/2013
• Issued: 11/07/2017
• Est. Priority Date: 10/10/2013
• Status: Active Grant

• Current Assignee: IPS Systems Incorporated
• Original Assignee: Indy Power Systems, LLC
• Inventors: Hintz, Andrew Stephen
• Primary Examiner(s): Zhang, Jue
• Assistant Examiner(s): DANG, TRINH Q
• Application Number:
  US14/050,959
• Publication Number:
  US 20150103574A1
• Time in Patent Office: 1,489 Days
• Field of Search: 363 16, 363 17, 363 69, 363127, 363132, 363 55
• CPC Class Codes: H02J 2300/20 The dispersed energy generation being of renewable origin
• CPC Class Codes: H02J 3/18 Arrangements for adjusting, eliminating or compensating reactive power in networks for adjustment of voltage H02J3/16
• CPC Class Codes: H02J 3/26 Arrangements for eliminating or reducing asymmetry in polyphase networks
• CPC Class Codes: H02J 3/28 Arrangements for balancing of the load in a network by storage of energy
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/44 with means for ensuring correct phase sequence
• CPC Class Codes: H02J 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• CPC Class Codes: H02J 3/48 Controlling the sharing of the in-phase component
• CPC Class Codes: H02J 3/50 Controlling the sharing of the out-of-phase component
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 1/42 Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
• CPC Class Codes: H02M 3/04 by static converters
• CPC Class Codes: H02M 7/53875 with analogue control of three-phase output
• CPC Class Codes: H02M 7/797 using semiconductor devices only
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y02E 40/30 Reactive power compensation
• CPC Class Codes: Y02E 40/50 Arrangements for eliminating or reducing asymmetry in polyphase networks
• CPC Class Codes: Y02P 80/14 District level solutions, i.e. local energy networks

Abstract

A converter system and inverter system are disclosed with individual real and reactive power control for each phase of a poly-phase system. The converter system includes a controller, bidirectional single-phase inverters with AC sides coupled to an AC line filter and DC sides connected in parallel to a link capacitor coupled to DC/DC converters. Each inverter handles a separate AC phase. The controller controls the inverters and DC/DC converters so the current amplitude of each AC phase is independent, and the phase difference of each AC phase is independent. The inverters can be galvanically isolated between the DC and AC sides. The inverters can be non-isolated inverters having line and neutral connectors coupled to an isolated transformer winding, and the output windings of the transformer can be wired in a Wye configuration. The inverters can have local controllers.

Claims

1. A bi-directional poly-phase DC/AC inverter comprising:

an AC side configured to receive input AC power from an AC source and configured to source output AC power to an AC load, each of the input and output AC power comprising a plurality of AC phases, each AC phase of the plurality of AC phases including a current waveform having a current amplitude and a current phase angle and a voltage waveform having a voltage amplitude and a voltage phase angle;

a DC side configured to receive input DC power and configured to source output DC power;

wherein when the output AC power is greater than the input AC power, the input DC power from the DC side is supplied through the bi-directional poly-phase DC/AC inverter to provide additional AC power to the AC load; and

when the input AC power is greater than the output AC power, excess power is provided through the bi-directional poly-phase DC/AC inverter to the DC side as the output DC power; and

wherein for each AC phase of the plurality of AC phases, the current amplitude of the current waveform is controlled independently of the current amplitude of the current waveform in the other AC phases of the plurality of AC phases, and for each AC phase of the plurality of AC phases, the difference between the current and voltage phase angles is controlled independently of the difference between the current and voltage phase angles in the other AC phases of the plurality of AC phases.

2. The bi-directional poly-phase DC/AC inverter of claim 1, wherein the AC power comprises three AC phases.

3. The bi-directional poly-phase DC/AC inverter of claim 2, wherein the bi-directional poly-phase DC/AC inverter comprises three separate bi-directional single-phase DC/AC inverters, each of the three separate bi-directional single-phase DC/AC inverters controlling a different one of the three AC phases.

4. The bi-directional poly-phase DC/AC inverter of claim 3, wherein each of the three separate bi-directional single-phase DC/AC inverters is galvanically isolated from the DC side to the AC side.

5. The bi-directional poly-phase DC/AC inverter of claim 3, wherein each of the three separate bi-directional single-phase DC/AC inverters is a non-isolated single-phase inverter having a line connector and a neutral connector coupled to an isolation transformer having output windings;

the output windings of the isolation transformer being wired in a Wye configuration.

6. The bi-directional poly-phase DC/AC inverter of claim 5, wherein each of the three separate bi-directional single-phase DC/AC inverters comprises an H-bridge comprised of a plurality of power switching devices.

7. The bi-directional poly-phase DC/AC inverter of claim 5, wherein each of the three separate bi-directional single-phase DC/AC inverters comprises an H-bridge comprised of four power switching devices.

8. The bi-directional poly-phase DC/AC inverter of claim 5, wherein each of the three separate bi-directional single-phase DC/AC inverters comprises an H-bridge comprised of four power switching devices in parallel with diodes wired in an anti-parallel configuration.

9. The bi-directional poly-phase DC/AC inverter of claim 5, wherein each of the non-isolated single-phase inverters further comprises a local controller.

10. The bi-directional poly-phase DC/AC inverter of claim 7, wherein the four power switching devices are four MOSFET transistors.

11. The bi-directional poly-phase DC/AC inverter of claim 8, wherein the four power switching devices are four IGBT transistors.

12. The bi-directional poly-phase DC/AC inverter of claim 9, wherein each of the three separate bi-directional single-phase DC/AC inverters comprises an H-bridge comprised of a plurality of power switching devices.

13. The bi-directional poly-phase DC/AC inverter of claim 9, wherein each of the three separate bi-directional single-phase DC/AC inverters comprises an H-bridge comprised of four power switching devices.

14. The bi-directional poly-phase DC/AC inverter of claim 11, wherein each of the three separate bi-directional single-phase DC/AC inverters comprises an H-bridge comprised of four power switching devices in parallel with diodes wired in an anti-parallel configuration.

15. The bi-directional poly-phase DC/AC inverter of claim 13, wherein the four power switching devices are four MOSFET transistors.

16. The bi-directional poly-phase DC/AC inverter of claim 14, wherein the four power switching devices are four IGBT transistors.

17. A converter system with individual real and reactive power control for each phase of a poly-phase system, the converter system coupling one or more DC loads/sources to one or more AC loads/sources using AC power having a plurality of AC phases, each AC phase of the plurality of AC phases including a current waveform having a current amplitude and a current phase angle and a voltage waveform having a voltage amplitude and a voltage phase angle, the converter system comprising:

a bidirectional poly-phase DC/AC inverter comprised of a plurality of bidirectional single-phase DC/AC inverters, each of the plurality of bidirectional single-phase DC/AC inverters having an AC side and a DC side, and each of the plurality of bidirectional single-phase DC/AC inverters handling a separate AC phase of the plurality of AC phases of the AC power;

the AC side of each of the plurality of bidirectional single-phase DC/AC inverters configured to receive input AC power from and configured to source output AC power to the AC loads/sources, and the DC side of each of the plurality of bidirectional single-phase DC/AC inverters configured to receive input DC power from and configured to source output DC power to the DC loads/sources;

an AC line filter having an AC inverter side and an AC source/load side, the AC inverter side being coupled to the AC sides of the plurality of bidirectional single-phase DC/AC inverters and the AC source/load side being coupled to the AC loads/sources;

a link capacitor connected in parallel with the DC sides of the plurality of bidirectional single-phase DC/AC inverters;

at least one bidirectional DC to DC converter connected in parallel with the link capacitor, the at least one bidirectional DC to DC converter being coupled to the DC loads/sources;

a controller that controls the plurality of bidirectional single-phase DC/AC inverters and the at least one bidirectional DC to DC converter;

the controller controls the current amplitude of the current waveform of each AC phase of the plurality of AC phases independently of the current amplitude of the current waveform of the other AC phases of the plurality of AC phases, and the controller controls the difference between the current and voltage phase angles of each AC phase of the plurality of AC phases independently of the difference between the current and voltage phase angles of the other AC phases of the plurality of AC phases.

18. The converter system of claim 17, wherein the plurality of bidirectional single-phase DC/AC inverters consists of three separate bidirectional single-phase DC/AC inverters;

and all of the AC loads/sources use three phase AC power.

19. The converter system of claim 18, wherein each of the three separate bidirectional single-phase DC/AC inverters is galvanically isolated from the DC side to the AC side.

20. The converter system of claim 18, wherein each of the three separate bidirectional single-phase DC/AC inverters is a non-isolated single-phase inverter having a line connector and a neutral connector coupled to an isolation transformer having output windings;

the output windings of the isolation transformer being wired in a Wye configuration.