Bidirectional electrical signal converter

Patent metadata

Field	Value
Publication number	US-10033182-B2
Application number	US-201414906879-A
Country	US
Kind code	B2
Filing date	Jul 22, 2014
Priority date	Jul 22, 2013
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

A bidirectional AC-to-DC and DC-to-AC circuit includes a first inductor-capacitor (LC) circuit connected to an AC power source, a transistor synchronized with the AC power source signal, a second LC circuit electrically connected to the synchronized transistor and the first inductor-capacitor circuit, a high-frequency switching transistor electrically connected to the second inductor-capacitor circuit and a direct current (DC) load, and a controller connected to the high-frequency switching transistor. The controller identifies an error between a measured DC output signal and a predetermined DC output signal that is applied to the DC load, and adjusts a duty cycle of a pulse width modulation (PWM) switching signal for the high-frequency transistor to reduce the identified error.

First claim

What is claimed is:

1. A power converter comprising:
a first inductor-capacitor circuit electrically connected to an alternating current (AC) power source;
a first switching transistor electrically connected to the first inductor-capacitor circuit;
a second inductor-capacitor circuit electrically connected to the first switching transistor and the first inductor-capacitor circuit;
a first high-frequency switching transistor electrically connected to the second inductor-capacitor circuit and a direct current (DC) load; and
a controller operatively connected to the first switching transistor and the first high-frequency switching transistor to operate the power converter in an AC-to-DC conversion mode, the controller being configured to:
operate the first switching transistor and the first high-frequency switching transistor to generate a DC output signal for the DC load from the AC power source;
identify an error between a measurement of the DC output signal from the first high-frequency switching transistor and a predetermined DC output signal level for the DC load; and
adjust a duty cycle of a pulse width modulation (PWM) switching signal with reference to the identified error and a proportional-integral-differential (PID) controller to switch the high-frequency switching transistor at a predetermined frequency with the adjusted duty cycle to reduce the identified error in the DC output signal.

2. The power converter of claim 1 , the controller being further configured to:
switch off the first switching transistor when the first high-frequency switching transistor is switched on.

3. The power converter of claim 1 further comprising:
a voltage sensor operatively connected to an output of the AC power source and configured to identify a level of AC voltage from the AC power source; and
the controller being operatively connected to the first switching transistor and the voltage sensor, the controller being further configured to:
switch off the first switching transistor in response to a negative level of AC voltage from the AC power source.

4. The power converter of claim 1 further comprising:
a current measurement sensor operatively connected to an output of the power converter and configured to identify a level of DC current applied to the DC load; and
the controller being operatively connected to the current measurement sensor and configured to:
switch off the high-frequency transistor in response to the level of DC current applied to the DC load exceeding a predetermined maximum level.

5. The power converter of claim 1 , wherein the power converter is configured to generate the DC output at a selected voltage level to drive different DC loads using the AC input source.

6. The power converter of claim 4 further comprising an analog to digital converter (ADC) operatively connected to the current measurement sensor and the controller.

7. The power converter of claim 1 , wherein the controller comprises a signal generator module configured to generate a sawtooth signal.

8. The power converter of claim 1 , wherein the controller comprises a difference module that subtracts a measured voltage from a reference voltage.

9. The power converter of claim 8 , wherein the controller comprises a proportional, integral, differential (PID) control module operatively connected to the difference module.

10. The power converter of claim 9 , wherein the PID control module sets a control point threshold to adjust the duty cycle of the PWM switching signal with reference to the identified error and the proportional-integral-differential (PID) controller.

11. The power converter of claim 8 , wherein the controller comprises a control module having control logic selected from the group consisting of PI, adaptive, self-tuning, variable structure, sliding mode, optimal, robust, and model predictive control logic.

12. The power converter of claim 1 , the controller being further configured to adjust the duty cycle of the PWM switching signal with reference to the identified error and an output of a control module having control logic selected from the group consisting of PI, adaptive, self-tuning, variable structure, sliding mode, optimal, robust, and model predictive control logic.

13. A power converter comprising:
a first inductor-capacitor circuit electrically connected to an alternating current (AC) power source;
a first switching transistor electrically connected to the first inductor-capacitor circuit;
a second inductor-capacitor circuit electrically connected to the first switching transistor and the first inductor-capacitor circuit;
a first high-frequency switching transistor electrically connected to the second inductor-capacitor circuit and a direct current (DC) load;
a controller operatively connected to the first switching transistor and the first high-frequency switching transistor to operate the power converter in an AC-to-DC conversion mode, the controller being configured to:
operate the first switching transistor and the first high-frequency switching transistor to generate a DC output signal for the DC load from the AC power source;
identify an error between a measurement of the DC output signal from the first high-frequency switching transistor and a predetermined DC output signal level for the DC load; and
adjust a duty cycle of a pulse width modulation (PWM) switching signal to switch the high-frequency switching transistor at a predetermined frequency with the adjusted duty cycle to reduce the identified error in the DC output signal;

a voltage sensor operatively connected to an output of the AC power source and configured to identify a level of AC voltage from the AC power source; and
the controller being operatively connected to the first switching transistor and the voltage sensor, the controller being further configured to switch off the first switching transistor in response to a positive level of AC voltage from the AC power source.

14. The power converter of claim 13 further comprising an analog to digital converter (ADC) operatively connected to the voltage sensor and the controller.

15. A power converter comprising:
a first inductor-capacitor circuit electrically connected to an alternating current (AC) power source;
a first switching transistor electrically connected to the first inductor-capacitor circuit;
a second inductor-capacitor circuit electrically connected to the first switching transistor and the first inductor-capacitor circuit;
a first high-frequency switching transistor electrically connected to the second inductor-capacitor circuit and a direct current (DC) load;
a controller operatively connected to the first switching transistor and the first high-frequency switching transistor to operate the power converter in an AC-to-DC conversion mode, the controller being configured to:
operate the first switching transistor and the first high-frequency switching transistor to generate a DC output signal for the DC load from the AC power source;
identify an error between a measurement of the DC output signal from the first high-frequency switching transistor and a predetermined DC output signal level for the DC load; and
adjust a duty cycle of a pulse width modulation (PWM) switching signal to switch the high-frequency switching transistor at a predetermined frequency with the adjusted duty cycle to reduce the identified error in the DC output signal;

a second switching transistor electrically connected to the first inductor-capacitor circuit and configured to switch at predetermined switching frequency corresponding to a frequency of an AC output signal for

Assignees

• Univ Indiana Res & Tech Corp

Inventors

• Izadian Afshin

Classifications

• H02J7/865

  Battery or charger load switching, e.g. concurrent charging and load supply (H02J7/50 takes precedence) · CPC title

• H02M7/68

  by static converters · CPC title

• H02M7/797

  using semiconductor devices only · CPC title

• H02J7/0068

  Electricity · mapped topic

• H02M7/04

  by static converters · CPC title