Bidirectional inverter-charger

• US 9,263,968 B2
• Filed: 06/22/2012
• Issued: 02/16/2016
• Est. Priority Date: 06/22/2011
• Status: Active Grant

• Current Assignee: Methode Electronics Incorporated
• Original Assignee: EEtrex Inc. (Methode Electronics Incorporated)
• Inventors: Potts, Dennis L., Houghton, Brian
• Primary Examiner(s): Tat, Binh
• Application Number:
  US13/530,806
• Publication Number:
  US 20130057200A1
• Time in Patent Office: 1,334 Days
• Field of Search: 716100-108, 320100-108
• US Class Current: 1/1
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: H02M 1/4233 using a bridge converter comprising active switches
• CPC Class Codes: H02M 3/33584 Bidirectional converters
• CPC Class Codes: H02M 7/4807 having a high frequency intermediate AC stage
• 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

Abstract

A bidirectional inverter-charger includes a first stage receiving or delivering energy from a line or to a load. The first stage including at least one inductor coupled with a split phase bridge. A link storage is connected between rails of a first bus and between the first stage and a second stage. The second stage includes a DC-to-DC converter connectable to a battery. The DC-to-DC converter includes a transformer providing galvanic isolation between a second bridge, connected between the rails of the first bus, and a third bridge connected between the rails of a second bus. In operation, the first stage provides power factor correction and a voltage boost while charging the battery and inverting when providing power to the line or the load. The second stage provides a controllable charge current to the battery and a voltage boost of a voltage of the battery to the link storage.

Claims

1. A bidirectional inverter-charger comprising:

a first stage configured to be coupled between a source of energy or a load and coupled with a link storage, the first stage including at least one inductor coupled with a first bridge receiving control signals from at least one digital controller;

a second stage coupled between the link storage and configured to be coupled with a battery, the second stage including a DC-to-DC converter receiving control signals from the at least one digital controller, the DC-to-DC converter comprising a transformer coupled between a first H-bridge and a second H-bridge, the first H-bridge coupled with the link storage and the second H-bridge coupleable with the battery;

the first stage providing power factor correction and a voltage boost of the source of energy to the link storage while charging the battery and inverting when providing power to the source of energy or the load from the battery;

the second stage providing a controllable charge current to the battery while charging the battery and providing a voltage boost of a voltage of the battery to the link storage while inverting the power from the battery;

while charging the battery, the first H-bridge providing a first square wave to the transformer from the link storage, the transformer providing isolation and providing the first square wave to the second H-bridge, the second H-bridge rectifying the first square wave to provide a specified charge current to the battery;

and while inverting, the second H-bridge providing a second square wave to the transformer from the battery, the transformer providing isolation and providing the second square wave to the first H-bridge, the first H-bridge rectifying the second square wave and providing a voltage to the link storage.

2. The bidirectional inverter-charger of claim 1 wherein the first bridge comprises a split phase.

3. The bidirectional inverter-charger of claim 2 wherein:

the at least one inductor comprises a first inductor coupled between a line of the source of energy and the split-phase bridge and a second inductor coupled between an opposite line of the source of energy and an opposite side of the split-phase bridge;

the split-phase bridge comprising at least four sets of high power semiconductor switches, the control signals driving the split-phase bridge to boost a voltage at the link storage to a specified voltage above a voltage of the source of energy, the boosted voltage provided, in part, by the first inductor and the second inductor, and to provide power factor correction.

4. The bidirectional inverter-charger of claim 1 wherein the first H-bridge comprises four sets of high power semiconductor switches and the second H-bridge comprises four sets of high power semiconductor switches.

5. The bidirectional inverter-charger of claim 1 wherein the at least one digital controller includes a first microcontroller providing control signals to the first stage at one frequency and the same or a second microcontroller providing control signals to the second stage at the same or different frequency.

6. The bidirectional inverter-charger of claim 1 wherein the link storage comprises at least one first capacitor coupled between a positive rail and a neutral line voltage and at least one second capacitor coupled between a negative rail and the neutral line voltage, the at least one first capacitor and the at least one second capacitor providing a link voltage to the second stage.

7. The bidirectional inverter-charger of claim 1 wherein the at least one inductor of the first stage further comprises:

a first inductor connected between a first line of the source of energy and a first portion of the first bridge; and

a second inductor connected between a second line of the source of energy and a second portion of the first bridge;

the first stage further comprising;

a first capacitor coupled between the first line and a neutral line and a second capacitor coupled between the second line and the neutral line.

8. The bidirectional inverter-charger of claim 7 wherein the link storage is connected between a first positive bus and a first negative bus, the link storage comprising a third capacitor connected between the first positive bus and the neutral line and a fourth capacitor connected between the first negative bus and the neutral line.

9. The bidirectional inverter-charger of claim 8 wherein the link storage further comprises a fifth capacitor coupled between the first positive bus and the first negative bus.

10. The bidirectional inverter-charger of claim 2 wherein the at least one inductor of the first stage further comprises:

a first inductor coupled between a first line of the source of energy and a first portion of the first bridge; and

a second inductor coupled between a second line/neutral of the source of energy and a second portion of the first bridge;

the link storage comprising a capacitor coupled between a first positive bus and a first negative bus.

11. The bidirectional inverter-charger of claim 1 wherein the first bridge comprises a three phase bridge inverter and wherein the at least one inductor comprises:

a first inductor coupled between a first line of a three phase energy supply and a first portion of the three phase bridge inverter;

a second inductor coupled between a second line of the three phase energy supply and a second portion of the three phase bridge inverter; and

a third inductor coupled between a third line of the three phase energy supply and a third portion of the three phase bridge inverter;

the first stage further comprising a first capacitor coupled between the first line and the third line, a second capacitor coupled between the first line and the second line, and a third capacitor coupled between the second line and the third line.

12. The bidirectional inverter-charger of claim 1 wherein the first stage includes a first zero-voltage-switching circuit on a first phase-leg of the source of energy and a second zero-voltage-switching circuit on a second phase-leg of the source of energy.

13. The bidirectional inverter-charger of claim 12 further comprising a virtual neutral that is separate from a line neutral.

14. The bidirectional inverter-charger of claim 12 further comprising a half-power point that is separate from a line neutral.

15. A bidirectional inverter-charger comprising:

a first stage including a first inductor operable to be coupled with a first phase leg and a second inductor operable to be coupled with a second phase leg, the first stage further including a split phase bridge including at least four transistor switches with the first inductor coupled between a first transistor and a second transistor of the split phase bridge and the second inductor coupled between a third transistor and a fourth transistor of the split phase bridge, the split phase bridge connected between a first positive bus and a first negative bus;

a link capacitor arrangement comprising a first capacitor coupled between the first positive bus and a neutral line, a second capacitor coupled between the neutral line and the first negative bus, and a third capacitor coupled between the first positive bus and the first negative bus;

a second stage coupled between the link capacitor arrangement and configured to connect with a battery, the second stage including a dual active bridge comprising a first H-bridge coupled between the first positive bus and the second negative bus wherein the battery may be connected between a second positive bus and the second negative bus, a second H-bridge coupled between the second positive bus and a second negative bus, and a transformer coupled between the first H-bridge and the second H-bridge, the transformer isolating the first positive bus and the first negative bus from the second positive bus and the second negative bus;

the first stage providing power factor correction and a voltage boost to the link capacitor arrangement while charging the battery, and inverting when providing power from the battery;

the second stage providing a controllable charge current to the battery while charging the battery and providing a voltage boost of a voltage of the battery to the link capacitor arrangement while inverting the power from the battery;

while charging the battery, the first H-bridge providing a first square wave to the transformer from the link storage, the transformer providing the first square wave to the second H-bridge, the second H-bridge rectifying the first square wave to provide a specified charge current to the battery; and

while inverting, the second H-bridge providing a second square wave to the transformer from the battery, the transformer providing the second square wave to the first H-bridge, the first H-bridge rectifying the second square wave and providing a voltage to the link storage.

16. The bidirectional inverter-charger of claim 15 further comprising:

a first zero-voltage-switching circuit on the first phase leg and a second zero-voltage-switching circuit on the second phase leg.

17. The bidirectional inverter-charger of claim 16 wherein the first stage further comprises:

a fourth capacitor coupled between the first phase leg and the neutral line, a fifth capacitor coupled between the neutral line and the second phase leg, and a sixth capacitor coupled between the first phase leg and the second phase leg.

18. The bidirectional inverter-charger of claim 17 further comprising a seventh capacitor coupled between the second positive bus and the second negative bus.