Inverter capacitor with phase-out bus bar

• US 10,574,151 B2
• Filed: 03/19/2019
• Issued: 02/25/2020
• Est. Priority Date: 08/11/2017
• Status: Active Grant

• Current Assignee: GalaTech, Inc.
• Original Assignee: GalaTech, Inc.
• Inventors: Liu, Wenjun, Ramm, Robert James
• Primary Examiner(s): Nguyen, Matthew V
• Application Number:
  US16/358,477
• Publication Number:
  US 20190260302A1
• Time in Patent Office: 343 Days
• CPC Class Codes: H02M 7/003 Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: H02M 7/537 using semiconductor devices only, e.g. single switched pulse inverters
• CPC Class Codes: H05K 7/1432 specially adapted for power drive units or power converters
• CPC Class Codes: H05K 7/14329 specially adapted for the configuration of power bus bars
• CPC Class Codes: H05K 7/209 Heat transfer by conduction from internal heat source to heat radiating structure H05K7/20909 takes precedence
• CPC Class Codes: H05K 7/20927 Liquid coolant without phase change

Abstract

The various implementations described herein include inverter devices and systems. In one aspect, an inverter includes: a case; a capacitor within the case having a first terminal and a second terminal; a first bus bar including a first portion within the case and a second portion extending from the case to contact a first transistor; a second bus bar including a first portion situated in the case and a second portion extending from the case to contact a second transistor; and a phase-out bus bar including a first portion situated in the case, a second portion extending from the case to contact the first transistor, and a third portion extending from the case to contact the second transistor.

Claims

1. A three-phase inverter, comprising:

a sealed case;

a capacitor sealed in the case, the capacitor having a first terminal and a second terminal;

first, second, third, fourth, fifth and sixth transistors external to the case, wherein;

the first, third, and fifth transistors are coupled to the first terminal of the capacitor; and

the second, fourth, and sixth transistors are coupled to the second terminal of the capacitor;

a first bus bar to connect the first terminal of the capacitor to the first, third, and fifth transistors, the first bus bar comprising a first portion sealed in the case and respective portions extending from the case to contact respective transistors of the first, third, and fifth transistors;

a second bus bar to connect the second terminal of the capacitor to the second, fourth, and sixth transistors, the second bus bar comprising a first portion sealed in the case and respective portions extending from the case to contact respective transistors of the second, fourth, and sixth transistors;

a first phase-out bus bar to connect the first transistor to the second transistor and to provide a first phase of alternating current, the first phase-out bus bar comprising a portion sealed in the case and respective portions extending from the case to contact respective transistors of the first and second transistors;

a second phase-out bus bar to connect the third transistor to the fourth transistor and to provide a second phase of alternating current, the second phase-out bus bar comprising a portion sealed in the case and respective portions extending from the case to contact respective transistors of the third and fourth transistors; and

a third phase-out bus bar to connect the fifth transistor to the sixth transistor and to provide a third phase of alternating current, the third phase-out bus bar comprising a portion sealed in the case and respective portions extending from the case to contact respective transistors of the fifth and sixth transistors.

2. The inverter of claim 1, wherein the portion sealed in the case of each of the first, second, and third phase-out bus bars comprises a conductive sheet situated above the capacitor in the case.

3. The inverter of claim 1, wherein:

the first terminal of the capacitor is on the bottom of the capacitor;

the first portion of the first bus bar comprises a conductive sheet situated below the capacitor in the case;

the second terminal of the capacitor is on the top of the capacitor; and

the first portion of the second bus bar comprises a conductive sheet situated above the capacitor and below the portion of each of the first, second, and third phase-out bus bars that is sealed in the case.

4. The inverter of claim 1, wherein:

the first terminal of the capacitor is a positive terminal; and

the second terminal of the capacitor is a negative terminal.

5. The inverter of claim 1, wherein the case is sealed with epoxy.

6. The inverter of claim 1, wherein:

the first, second, third, fourth, fifth and sixth transistors are insulated-gate bipolar transistors, each comprising an emitter, a collector, and a gate;

the collector of each transistor of the first, third, and fifth transistors is coupled to the first terminal of the capacitor via the first bus bar; and

the emitter of each of the second, fourth, and sixth transistors is coupled to the second terminal of the capacitor via the second bus bar.

7. The inverter of claim 1, wherein:

the first, second, third, fourth, fifth and sixth transistors are silicon-carbide metal-oxide-semiconductor field-effect transistors (SiC MOSFETs) or gallium-nitride field-effect transistors (GaN FETs), each comprising a first source/drain terminal, a second source/drain terminal, and a gate;

the first source/drain terminal of each of the first, third, and fifth transistors is coupled to the first terminal of the capacitor via the first bus bar; and

the second source/drain terminal of each of the second, fourth, and sixth transistors is coupled to the second terminal of the capacitor via the second bus bar.

8. The inverter of claim 1, further comprising one or more heat sinks to provide heat-sinking for the first and second transistors;

wherein the first, second, third, fourth, fifth and sixth transistors are situated between the case and the one or more heat sinks.