Bidirectional chopping of high voltage power in high temperature downhole tools to reduce tool size

Patent metadata

Field	Value
Publication number	US-10858911-B2
Application number	US-201514845693-A
Country	US
Kind code	B2
Filing date	Sep 4, 2015
Priority date	Sep 4, 2015
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

A downhole tool and a method for operating the downhole tool are disclosed. A first power signal is supplied to the downhole tool from a power source at a first frequency. A bidirectional chopper at the downhole tool chops the first power signal to generate a second power signal having a second frequency greater than the first frequency. The second power signal is used to operate the downhole tool.

First claim

The invention claimed is:

1. A method of operating a downhole tool, comprising:
supplying an alternating current (AC) input power signal at a first frequency to the downhole tool from a power source;
chopping the AC input power signal at a bidirectional chopping circuit disposed in the downhole tool to generate an AC output power signal having a second frequency greater than the first frequency, the bidirectional chopping circuit including four switch sections, wherein the AC input power signal includes a first AC input signal received at a first and second switch section and a second AC input signal received at a third and fourth switch section and the AC output power signal includes a first AC output signal produced by the first and third switch sections and a second AC output signal produced by the second and fourth switch sections;
receiving the first AC output power signal at a transformer;
stepping down the voltage of the first AC output power signal at the transformer; and
operating motor electronics of the downhole tool based on the stepped down AC output power signal to operate a motor of the downhole tool.

2. The method of claim 1 , further comprising using the transformer disposed in the downhole tool to perform at least one of: (i) change a voltage of the AC output power signal prior to using the AC output power signal to operate the downhole tool; and (ii) galvanically isolate the downhole tool from a surface power supply.

3. The method of claim 1 , further comprising receiving a first pulse width modulated (PWM) control signal at the first and third switch sections and a second PWM control signal at the second and fourth switch sections.

4. The method of claim 3 , wherein the first PWM signal and the second PWM signal are 180 degrees out of phase and have a 50% duty cycle.

5. The method of claim 3 , wherein changing a duty cycle of the first PWM signal and the second PWM signal alters an amplitude of the AC output power signal.

6. The method of claim 3 , wherein at least one of the switch sections includes two transistors with antiparallel diodes and the transistors include at least one of: (i) a silicon transistor; (ii) an insulated-gate bipolar transistor: (iii) a wide band-gap material transistor; (iv) a silicon carbide transistor; and (v) a gallium nitride transistor.

7. The method of claim 6 , wherein the sources of the two transistors are electrically coupled and the gates of the two transistors are electrically coupled.

8. The method of claim 1 , wherein the first frequency is in a range from about 50 Hertz (Hz) to about 60 Hz and the second frequency is in a range between about 400 Hz to about 1 kHz.

9. A downhole tool, comprising:
a bidirectional chopper disposed in the downhole tool that receives an alternating current (AC) input power signal at a first frequency and chops the AC input power signal to generate an AC output power signal having a second frequency greater than the first frequency, the bidirectional chopping circuit including four switch sections, wherein the AC input power signal includes a first AC input signal received at a first and second switch section and a second AC input signal received at a third and fourth switch section and the AC output power signal includes a first AC output signal produced by the first and third switch sections and a second AC output signal produced by the second and fourth switch sections;
a transformer that receives the first AC output power signal and steps down the voltage of the first AC output power signal; and
a motor electronics of the downhole tool operable based on the stepped down AC output power signal to operate a motor of the downhole tool.

10. The downhole tool of claim 9 , wherein the transformer disposed in the downhole tool and configured to perform at least one of: (i) transform a voltage of the AC output power signal; and (ii) galvanically isolate the downhole tool from a surface power supply.

11. The downhole tool of claim 9 , wherein bidirectional chopper receives a first pulse width modulated (PWM) signal at the first and third switch sections and a second PWM signal at the second and fourth switch sections to control the chopping of the AC input power signal, wherein the first PWM signal and the second PWM signal are 180 degrees out of phase and have a 50% duty cycle.

12. The downhole tool of claim 11 , wherein at least one of the switch sections includes two transistors with antiparallel diodes and the transistors include at least one of: (i) a silicon transistor; (ii) an insulated-gate bipolar transistor: (iii) a wide band-gap material transistor; (iv) a silicon carbide transistor; and (v) a gallium nitride transistor.

13. A system for operating a motor of a downhole tool, comprising:
a power source configured to supply an alternating current (AC) input power signal at a first frequency;
a bidirectional chopper disposed in the downhole tool configured to receive the AC input power signal and chop the AC input power signal to generate an AC output power signal having a second frequency greater than the first frequency, the bidirectional chopping circuit including four switch sections, wherein the AC input power signal includes a first AC input signal received at a first and second switch section and a second AC input signal received at a third and fourth switch section and the AC output power signal includes a first output signal produced by the first and third switch sections and a second AC output signal produced by the second and fourth switch section; and
a transformer that receives the first AC output power signal and steps down the voltage of the first AC output power signal; and
a motor electronics of the downhole tool operable based on the stepped down AC output power signal to operate the motor of the downhole tool.

14. The system of claim 13 , wherein the transformer disposed in the downhole tool and configured to transform a voltage of the AC output power signal to signal at a selected power level.

15. The system of claim 13 , wherein at least one of the switch sections includes two transistors, each transistor having an antiparallel diode.

16. The system of claim 15 , wherein the bidirectional chopper receives a first pulse width modulated (PWM) signal at a first and third of the switch sections and a second PWM signal at a second and fourth of the switch sections to control the chopping of the AC input power signal.

Assignees

• Kulkarni Saurabh
• Baker Hughes A Ge Co Llc

Inventors

• Kulkarni Saurabh

Classifications

• H02M1/007

  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 title

• H02M7/68

  by static converters · CPC title

• H02M7/5387

  in a bridge configuration · CPC title

• H02M5/293

  using semiconductor devices only · CPC title

• H02M5/22

  using discharge tubes with control electrode or semiconductor devices with control electrode · CPC title