Power controller and power control method

• US 10,468,977 B2
• Filed: 11/13/2014
• Issued: 11/05/2019
• Est. Priority Date: 11/13/2014
• Status: Active Grant

• Current Assignee: University of Hong Kong (Government of Hong Kong Special Administrative Region)
• Original Assignee: University of Hong Kong (Government of Hong Kong Special Administrative Region)
• Inventors: Mok, Kwan Tat, Tan, Siew Chong, Hui, Shu Yuen Ron
• Primary Examiner(s): Nash, Gary A
• Application Number:
  US15/526,988
• Publication Number:
  US 20170324319A1
• Time in Patent Office: 1,818 Days
• Field of Search: 323213, 323241, 323275, 323283, 323285, 363 78
• CPC Class Codes: G05F 1/455 with phase control
• CPC Class Codes: G05F 1/565 sensing a condition of the system or its load in addition to means responsive to deviations in the output of the system, e.g. current, voltage, power factor G05F1/563 takes precedence
• CPC Class Codes: H02J 3/18 Arrangements for adjusting, eliminating or compensating reactive power in networks for adjustment of voltage H02J3/16
• CPC Class Codes: H02M 1/0003 Details of control, feedback or regulation circuits
• CPC Class Codes: H02M 1/0093 wherein the output is created by adding a regulated voltage to or subtracting it from an unregulated input
• CPC Class Codes: H02M 1/4208 Arrangements for improving power factor of AC input
• CPC Class Codes: H02M 1/4275 by adding an auxiliary output voltage in series to the input
• CPC Class Codes: H02M 5/293 using semiconductor devices only
• CPC Class Codes: H02M 5/2932 with automatic control of output voltage, current or power
• CPC Class Codes: H02M 7/219 in a bridge configuration
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• 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
• CPC Class Codes: Y02E 40/30 Reactive power compensation

Abstract

A power controller for an AC power converter connected in series with a load and receiving power from or delivering power to a power source, the power controller comprising: a radial control block controlling a radial component of an electrical parameter of the AC power converter; and a chordal control block controlling a chordal component of the electrical parameter of the AC power converter. Also provided is a power system comprising one or more loads each connected in series to a power converter each controlled by a power controller as described above. There is also provided a method of controlling an AC power converter connected in series with a load and receiving power from a power source, the method comprising: controlling a radial component of an electrical parameter of the AC power converter; and controlling a chordal component of the electrical parameter of the AC power converter.

Claims

1. A power controller for an AC/DC power converter comprising an AC power port and connected in series with a load through the AC power port comprising two connections, wherein the series connection between the AC/DC power converter and the load comprises one of the two connections of the AC power port of the AC/DC power converter being connected to an AC power source, and the other connection of the two connections being connected to the load, wherein both of the AC/DC power converter and the load are capable of being configured to receive power from and deliver power to the AC power source, the power controller comprising:

a radial control block that controls a radial component of an electrical parameter of the AC/DC power converter connected in series with the load through the AC power port; and

a chordal control block that controls a chordal component of the electrical parameter of the AC/DC power converter.

2. A power controller according to claim 1 wherein the electrical parameter is one of:

voltage, current, power, or frequency.

3. A power controller according to claim 1 comprising a first input, a second input, and a third input, wherein the first input is a magnitude of the electrical parameter of the AC power source, the second input is a desired magnitude of the radial component of the electrical parameter of the AC power converter, and the third input is a desired difference between a phase angle of the electrical parameter of the AC power source and a phase angle of the electrical parameter of the load.

4. A power controller according to claim 3 wherein the electrical parameter is voltage and the radial control block controls the radial component in accordance with the following relationships:

5. A power controller according to claim 3 wherein the electrical parameter is voltage and the chordal control block controls the chordal component in accordance with the following relationship:

6. A power controller according to claim 1 wherein the AC power source is a power grid and the power controller controls the radial and chordal components of the electrical parameter of the AC power converter in accordance with required values of one or more reference electrical parameters of the power grid.

7. A power controller according to claim 6 wherein the reference electrical parameters are one or more of the following:

voltage, current, power, and power factor.

8. A power controller according to claim 1 comprising a summation block combining the radial and chordal components of the electrical parameter of the AC power converter output by the radial and chordal control blocks respectively to provide a reference magnitude and a reference phase angle for the electrical parameter of the AC power converter.

9. A power controller according to claim 1 wherein the power controller controls the radial and chordal components of the electrical parameter of the AC power converter in accordance with required values of one or more reference electrical parameters of the load or the AC power source.

10. A power controller according to claim 1 wherein the power controller controls the radial and chordal components of the electrical parameter of the AC power converter to provide active and reactive power compensation to the AC power source.

11. A power controller according to claim 1 wherein the power controller is integrated with the AC power converter.

12. A power controller according to claim 1 wherein the power controller and the AC power converter are integrated with the load.

13. A power system comprising one or more loads each connected in series to an AC power converter each controlled by a power controller according to claim 1.

14. A method of controlling an AC/DC power converter comprising an AC power port and connected in series with a load through the AC power port comprising two connections, wherein the series connection between the AC/DC power converter and the load comprises one of the two connections of the AC power port of the AC/DC power converter being connected to an AC power source, and the other connection of the two connections being connected to the load, wherein both of the AC/DC power converter and the load are capable of being configured to receive power from and deliver power to the AC power source, the method comprising:

controlling a radial component of an electrical parameter of the AC/DC power converter connected in series with the load through the AC power port; and

controlling a chordal component of the electrical parameter of the AC/DC power converter.

15. A method according to claim 14 wherein the electrical parameter is one of:

voltage, current, power, or frequency.

16. A method according to claim 14 comprising controlling the radial and chordal components based on a magnitude of the electrical parameter of the AC power source, a desired magnitude of the radial component of the electrical parameter of the AC power converter, and a desired difference between a phase angle of the electrical parameter of the AC power source and a phase angle of the electrical parameter of the load.

17. A method according to claim 16 wherein the electrical parameter is voltage and the radial component is controlled in accordance with the following relationships:

18. A method according to claim 16 wherein the electrical parameter is voltage and the chordal component is controlled in accordance with the following relationship:

19. A method according to claim 14 comprising combining the radial and chordal components of the electrical parameter of the AC power converter to provide a reference magnitude and a reference phase angle for the electrical parameter of the AC power converter.

20. A method according to claim 14 wherein the AC power source is a power grid and the radial and chordal components of the electrical parameter of the AC power converter are controlled in accordance with required values of one or more reference electrical parameters of the power grid.

21. A method according to claim 20 wherein the reference electrical parameters are one or more of the following:

voltage, current, power, and power factor.

22. A method according to claim 14 wherein the radial and chordal components of the electrical parameter of the AC power converter are controlled in accordance with required values of one or more reference electrical parameters of the load or the AC power source.

23. A method according to claim 14 wherein the radial and chordal components of the electrical parameter of the AC power converter are controlled to provide active and reactive power compensation to the AC power source.