Systems and methods for paralleling 3-wire and 4-wire 3-phase active harmonic filters

Patent metadata

Field	Value
Publication number	US-11735917-B2
Application number	US-202117489245-A
Country	US
Kind code	B2
Filing date	Sep 29, 2021
Priority date	Apr 29, 2021
Publication date	Aug 22, 2023
Grant date	Aug 22, 2023

Abstract

Aspects of the disclosure include a power system comprising at least one three-wire active harmonic filter (AHF) configured to be coupled to, and provide compensation current to, a three-phase load, at least one four-wire AHF configured to be coupled to, and provide compensation current to, the three-phase load, and a controller configured to determine a total compensation current to provide to the three-phase load, the total compensation current including a zero component and a non-zero component, determine an output capacity of the at least one three-wire AHF and the at least one four-wire AHF, calculate a current-compensation ratio based on the output capacity of the at least one three-wire AHF and the at least one four-wire AHF, and control the at least one four-wire AHF to provide at least a portion of the non-zero component of the total compensation current to the three-phase load based on the current-compensation ratio.

First claim

What is claimed is:

1. A power system comprising:
at least one three-wire active harmonic filter (AHF) configured to be coupled to, and provide compensation current to, a three-phase load;
at least one four-wire AHF configured to be coupled to, and provide compensation current to, the three-phase load; and
a controller configured to
determine a total compensation current to provide to the three-phase load, the total compensation current including a zero component and a non-zero component;
determine an output capacity of the at least one three-wire AHF and the at least one four-wire AHF;
calculate a current-compensation ratio based on the output capacity of the at least one three-wire AHF and the at least one four-wire AHF; and
control the at least one four-wire AHF to provide at least a portion of the non-zero component of the total compensation current to the three-phase load based on the current-compensation ratio.

2. The power system of claim 1 , wherein the at least one three-wire AHF is coupled in parallel with the at least one four-wire AHF.

3. The power system of claim 1 , wherein the controller is further configured to control the at least one four-wire AHF to provide a zero compensation current to the three-phase load to satisfy the zero component of the total compensation current.

4. The power system of claim 3 , wherein the controller is configured to:
determine a remaining capacity of the at least one four-wire AHF after allocating the zero component of the total compensation current to the at least one four-wire AHF; and
determine whether the remaining capacity of the at least one four-wire AHF exceeds the non-zero component of the total compensation current.

5. The power system of claim 4 , wherein the controller is configured to allocate an entirety of the total compensation current to the at least one four-wire AHF responsive to determining that the remaining capacity of the at least one four-wire AHF exceeds the non-zero component of the total compensation current.

6. The power system of claim 5 , wherein the current-compensation ratio is one, and wherein the at least one three-wire AHF does not provide a compensation current to the three-phase load.

7. The power system of claim 4 , wherein the controller is configured to allocate the remaining capacity of the at least one four-wire AHF to non-zero compensation current responsive to determining that the non-zero component of the total compensation current exceeds the remaining capacity of the at least one four-wire AHF.

8. The power system of claim 7 , wherein the at least a portion of the non-zero component of the total compensation current is a first portion of non-zero compensation current provided to the three-phase load, and wherein a remaining portion of the non-zero compensation current is allocated to the at least one three-wire AHF.

9. The power system of claim 8 , wherein the current-compensation ratio is equal to the first portion of the non-zero compensation current divided by the non-zero compensation current.

10. A non-transitory computer-readable medium storing thereon sequences of computer-executable instructions for operating a power system including at least one three-wire active harmonic filter (AHF) and at least one four-wire AHF, each being configured to be coupled to, and provide compensation current to, a three-phase load, the sequences of computer-executable instructions including instructions that instruct at least one processor to:
determine a total compensation current to provide to the three-phase load, the total compensation current including a zero component and a non-zero component;
determine an output capacity of the at least one three-wire AHF and the at least one four-wire AHF;
calculate a current-compensation ratio based on the output capacity of the at least one three-wire AHF and the at least one four-wire AHF; and
control the at least one four-wire AHF to provide at least a portion of the non-zero component of the total compensation current to the three-phase load based on the current-compensation ratio.

11. The non-transitory computer-readable medium of claim 10 , wherein the instructions further instruct the at least one processor to control the at least one four-wire AHF to provide a zero compensation current to the three-phase load to satisfy the zero component of the total compensation current.

12. The non-transitory computer-readable medium of claim 11 , wherein the instructions further instruct the at least one processor to:
determine a remaining capacity of the at least one four-wire AHF after allocating the zero component of the total compensation current to the at least one four-wire AHF; and
determine whether the remaining capacity of the at least one four-wire AHF exceeds the non-zero component of the total compensation current.

13. The non-transitory computer-readable medium of claim 12 , wherein the instructions further instruct the at least one processor to allocate an entirety of the total compensation current to the at least one four-wire AHF responsive to determining that the remaining capacity of the at least one four-wire AHF exceeds the non-zero component of the total compensation current.

14. The non-transitory computer-readable medium of claim 13 , wherein the current-compensation ratio is one, and wherein the at least one three-wire AHF does not provide a compensation current to the three-phase load.

15. The non-transitory computer-readable medium of claim 12 , wherein the instructions further instruct the at least one processor to allocate the remaining capacity of the at least one four-wire AHF to non-zero compensation current responsive to determining that the non-zero component of the total compensation current exceeds the remaining capacity of the at least one four-wire AHF.

16. The non-transitory computer-readable medium of claim 15 , wherein the at least a portion of the non-zero component of the total compensation current allocated to the at least one four-wire AHF is a first portion of non-zero compensation current provided to the three-phase load, and wherein a remaining portion of the non-zero compensation current is allocated to the at least one three-wire AHF.

17. The non-transitory computer-readable medium of claim 16 , wherein the current-compensation ratio is equal to the first portion of the non-zero compensation current divided by the non-zero compensation current.

18. A method of operating a power system including at least one three-wire active harmonic filter (AHF) and at least one four-wire AHF, each being configured to be coupled to, and provide compensation current to, a three-phase load, the method comprising:
determining a total compensation current to provide to the three-phase load, the total compensation current including a zero component and a non-zero component;
determining an output capacity of the at least one three-wire AHF and the at least one four-wire AHF;
calculating a current-compensation ratio based on the output capacity of the at least one three-wire AHF and the at least one four-wire AHF; and
controlling the at least one four-wire AHF to provide at least a portion of the non-zero component of the total compensation current to the three-phase load based on the current-compensation ratio.

19. The method of claim 18 , further comprising:
controlling the at least one four-wire AHF to provide a zero compensation current to the three-phase load to satisfy the zero component of the total compensation current;
determining a remaining capacity of the at least

Assignees

• Schneider Electric Usa Inc

Inventors

• Marwali Mohammad Nanda Rahmana
• Batch John Simon

Classifications

• H02J3/01 Primary

  Arrangements for reducing harmonics or ripples · CPC title

• H02J3/1842 Primary

  having reactive elements actively controlled by bridge converters, e.g. active filters or static compensators [STATCOM] · CPC title

• H02J3/46

  Controlling the sharing of generated power between the generators, sources or networks · CPC title

• H02M7/487

  Neutral point clamped inverters · CPC title

• H02M7/797

  using semiconductor devices only · CPC title