DC to DC converter sourcing variable DC link voltage

Patent metadata

Field	Value
Publication number	US-10148212-B2
Application number	US-201715400316-A
Country	US
Kind code	B2
Filing date	Jan 6, 2017
Priority date	Jan 6, 2017
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

An inverter-converter system includes a DC source, a DC to DC boost converter, a DC link capacitor, an inverter circuit, a variable speed electric machine, and a controller. The DC to DC boost converter receives an input DC voltage from the DC source. The inverter circuit converts the variable boosted voltage to an AC voltage to drive the variable speed electric machine. The controller senses a plurality of parameters from the variable speed electric machine, and controls the DC to DC boost converter to boost up the input DC voltage to a variable output voltage based on the plurality of parameters and/or the voltage (or load) needed by the variable speed electric machine. The design of the inverter-converter system can achieve an electrical efficiency and cost savings for the overall system.

First claim

What is claimed is:

1. A DC to DC boost converter, comprising:
a first boost circuit having a first inductor and a first set of switches, the first inductor having a first end and a second end; and
a second boost circuit having a second inductor and a second set of switches, the second inductor having a first end and a second end,
wherein the first end of the first inductor connects to a DC source to receive an input DC voltage, the second end of the first inductor connects to the first end of the second inductor,
wherein the first inductor is connected to the second inductor in series when the first set of switches is off;
wherein when the second set of switches is off, the first set of switches is controlled to boost the input DC voltage to a first boosted voltage using the first inductor without the second inductor;
wherein when the first set of switches is off, the second set of switches is controlled to boost the input DC voltage to a second boosted voltage using the first inductor and the second inductor; and
wherein the second boosted voltage is greater than the first boosted voltage, the first boosted voltage is greater than the input DC voltage.

2. The DC to DC boost converter according to claim 1 , wherein the first set of switches and the second set of switches are MOSFET switches.

3. The DC to DC boost converter according to claim 2 , further comprising:
a DC link capacitor having a first end and a second end,
wherein the first set of switches includes a first switch element and a second switch element, the second set of switches includes a third switch element and a fourth switch element;
wherein the drain terminal of the second switch element and the drain terminal of the fourth switch element connect to the first end of the DC link capacitor;
wherein the source terminal of the first switch element and the source terminal of the third switch element connect to the second end of the DC link capacitor;
wherein the drain terminal of the third switch element and the source terminal of the fourth switch element connect to the second end of the second inductor; and
wherein the second end of the first inductor, the drain terminal of the first switch element, and the source terminal of the second switch element connect to the first end of the second inductor.

4. The DC to DC boost converter according to claim 1 , wherein the first inductor and the second inductor are tapped winding electromagnetic coils.

5. The DC to DC boost converter according to claim 1 , further comprising:
a third boost circuit having a third inductor and a third set of switches,
wherein the first inductor, the second inductor, and the third inductor are connected in series when both the first set of switches and the second set of switches are off;
wherein when both the second set of switches and the third set of switches are off, the first boost circuit is configured to boost the input DC voltage to the first boosted voltage;
wherein when both the first set of switches and the third set of switches are off, the first inductor and the second boost circuit are configured to boost the input DC voltage to the second boosted voltage; and
wherein when both the first set of switches and the second set of switches are off, the first inductor, the second inductor, and the third boost circuit are configured to boost the input DC voltage to a third boosted voltage.

6. The DC to DC boost converter according to claim 1 , wherein the DC to DC boost converter is configured to provide the first boosted voltage to operate a compressor at a first speed, and the DC to DC boost converter is configured to provide the second boosted voltage to operate the compressor at a second speed that is greater than the first speed.

7. The DC to DC boost converter according to claim 6 , wherein the DC to DC boost converter is connected to the compressor via an inverter.

8. An inverter-converter system, comprising:
a DC to DC boost converter, the DC to DC boost converter includes:
a first boost circuit having a first inductor and a first set of switches, the first inductor having a first end and a second end, and
a second boost circuit having a second inductor and a second set of switches, the second inductor having a first end and a second end,
wherein the first end of the first inductor connects to a DC source to receive an input DC voltage, the second end of the first inductor connects to the first end of the second inductor,
wherein the first inductor is connected to the second inductor in series when the first set of switches is off,
wherein when the second set of switches is off, the first set of switches is controlled to boost the input DC voltage to a first boosted voltage using the first inductor without the second inductor,
wherein when the first set of switches is off, the second set of switches is controlled to boost the input DC voltage to a second boosted voltage using the first inductor and the second inductor; and
wherein the second boosted voltage is greater than the first boosted voltage, the first boosted voltage is greater than the input DC voltage;

the DC source providing the input DC voltage to the DC to DC boost converter;
a variable speed electric machine; and
a controller that determines a load of the variable speed electric machine and controls the first and the second sets of switches based on the sensed load of the variable speed electric machine,
wherein the DC to DC boost converter is configured to source one of the first boosted voltage and the second boosted voltage to the variable speed electric machine based on the sensed load of the variable speed electric machine.

9. The inverter-converter system according to claim 8 , further comprising:
an inverter circuit for converting one of the first boosted voltage and the second boosted voltage to an AC voltage,
wherein the variable speed electric machine is driven by the AC voltage.

10. The inverter-converter system according to claim 8 , wherein the input DC voltage is about 12 volts.

11. The inverter-converter system according to claim 8 , wherein the DC source is one of a battery source, a DC source, and a rectified AC source.

12. The inverter-converter system according to claim 8 , wherein the first boosted voltage is about 170 volts and the second boosted voltage is about 340 volts.

13. The inverter-converter system according to claim 8 , wherein the variable speed electric machine is a multi-speed AC-driven compressor.

14. The inverter-converter system according to claim 8 , wherein the variable speed electric machine is a compressor, the DC to DC boost converter is configured to provide the first boosted voltage to operate the compressor at a first speed, and the DC to DC boost converter is configured to provide the second boosted voltage to operate the compressor at a second speed that is greater than the first speed.

15. The inverter-converter system according to claim 14 , wherein the DC to DC boost converter is connected to the compressor via an inverter.

16. A method for operating a DC to DC boost converter, the DC to DC boost converter including a first boost circuit having a first inductor and a first set of switches, the first inductor having a first end and a second end; and a second boost circuit having a second inductor and a second set of switches, the second inductor having a first end and a second end, wherein the first end of the first inductor connects to a DC source to receive an input DC voltage, the second end of the first inductor connects to the first end of the second inductor, wherein the first inductor is c

Assignees

• Thermo King Corp

Inventors

• Schumacher Ryan Wayne
• Andrade Dias Marcelo

Classifications

• F25B2600/0252

  with two speeds · CPC title

• F25B2600/0253

  with variable speed · CPC title

• F25B49/022

  Compressor control arrangements · CPC title

• H02P25/02 Primary

  characterised by the kind of motor · CPC title

• H02M7/06

  using discharge tubes without control electrode or semiconductor devices without control electrode · CPC title