Modular intelligent combined wind power converter and control method thereof

Patent metadata

Field	Value
Publication number	US-11677334-B2
Application number	US-202117630136-A
Country	US
Kind code	B2
Filing date	Jan 12, 2021
Priority date	Jul 15, 2020
Publication date	Jun 13, 2023
Grant date	Jun 13, 2023

Abstract

The present invention discloses a modular intelligent combined wind power converter and a control method thereof. The modular intelligent combined wind power converter comprises separate bridge arm power units, wherein a plurality of the bridge arm power units are connected in parallel to form a high-capacity bridge arm power module, three bridge arm power modules form a three-phase full-controlled bridge power module, and the three-phase full-controlled bridge power module comprises an electric reactor, a capacitor, a fuse and a circuit breaker to form a basic converter module, and the basic converter module forms a high-capacity wind power converter through a modular intelligent combination method.

First claim

The invention claimed is:

1. A modular intelligent combined wind power converter, comprising:
a plurality of bridge arm power units, wherein the plurality of the bridge arm power units is connected in parallel to form bridge arm power modules having a high-capacity, three of the bridge arm power modules form a three-phase full-controlled bridge power module, the three-phase full-controlled bridge power module comprises an electric reactor, a capacitor, a fuse, and a circuit breaker to form a basic converter module, and the basic converter module forms the modular intelligent combined wind power converter through a modular intelligent combination method;
wherein
the modular intelligent combined wind power converter can control accurate turn-on and turn-off of a bridge arm power switch through an intelligent driving unit of a power device, and a current-sharing controller is integrated in each of the bridge arm power modules for achieving current sharing of each of bridge arms in the bridge arm power modules;
a driving controller is integrated in the three-phase full-controlled bridge power module for achieving different switch combinations of the three bridge arm power modules; the basic converter module is integrated with a converter main controller for controlling an output current of a converter, and intelligent identification and on-line hot plugging of a converter power unit can be achieved through a converter modular intelligent combination method; the converter main controller comprises a main control unit used for achieving basic control of grid connection and a wind driven generator; the main control unit comprises an active circulation control module, a grid-connected current harmonic optimization control module, a converter thermal stress balance control module, a parallel current-sharing control module, a converter stability control module, and a power grid impedance self-adaptive control module;
wherein current control is achieved by a control unit in each basic converter module, a power module expansion automatic identification circuit is used for identifying whether a basic power module is accessed or not and achieving an on-line hot plugging function of the basic power module through the converter main controller of the wind power converter, and a control power module takes power from an alternating-current (AC) terminal and a direct-current (DC) terminal to supply power to a control circuit;
wherein the three-phase full-controlled bridge power module comprises a power unit and a control unit, wherein
the power unit comprises three same bridge arm power modules, a port 1 of a bridge arm power module A, a port 1 of a bridge arm power module B and a port 1 of a bridge arm power module C are connected together to form a DC port P of the power unit; a port 3 of the bridge arm power module A, a port 3 of the bridge arm power module B and a port 3 of the bridge arm power module C are connected together to form a DC port N of the power unit; a port 2 of the bridge arm power module A is an AC port A of the power unit; a port 2 of the bridge arm power module B is an AC port B of the power module; and a port 2 of the bridge arm power module C is an AC port C of the power unit;
wherein the main control unit comprises
a full FPGA controller receiving control command words sent from the converter main controller through a high-speed communication interface, and a format of the control command words being as follows:

ID
SYN
TSA
DA
SA
TSB
DB
SB
TSC
DC
SC

wherein ID represents an identification code of the power unit; SYN is synchronous frame data; TSA represents a control cycle of the bridge arm power module A; DA represents a turn-on duty ratio of the bridge arm power module A; SA represents a phase shift angle of the bridge arm power module A; TSB represents a control cycle of the bridge arm power module B; DB represents a turn-on duty ratio of the bridge arm power module B; SB represents a phase shift angle of the bridge arm power module B; TSC represents a control cycle of the bridge arm power module C;
DC represents a turn-on duty ratio of the bridge arm power module C; and SC represents a phase shift angle of the bridge arm power module C;
wherein the plurality of bridge arm power units comprises achieving bridge arm power modules by connecting at least one bridge arm power unit in parallel, and a current-sharing control of bridge arm basic units in parallel connection is achieved through self-adaptive current-sharing control, the control being as follows:
forming the at least one bridge arm power unit by n same bridge arm basic units and the intelligent driving unit of the power device, sending, by each of the bridge arms, currents and switch-on voltages of an upper switch tube and a lower switch tube to a bridge arm module controller FPGA (field-programmable gate array), and computing, by the bridge arm module controller FPGA, an average current i avg according to currents of the bridge arms;
when a current i ci of an i-th bridge arm is more than i avg , reducing a driving voltage corresponding to the upper switch tube and the lower switch tube, and when the current i ci of the i-th bridge arm is less than i avg , increasing the driving voltage corresponding to the upper switch tube and the lower switch tube, wherein a computational formula of a driving voltage variation is:

Δ
⁢

U
Gi

=

K

G
⁢
1

⁢

K

G
⁢
2

(

i
avg

-

i
ci

)

=

K

G
⁢
1

⁢

K

G
⁢
2

(

1
n

⁢

Assignees

• Univ Shanghai Jiaotong

Inventors

• Cai Xu
• Wang Han
• Zhang Jianwen
• Shi Gang
• Lv Jing
• Cao Yunfeng
• Shao Haoshu
• Qin Yao
• Lv Wei

Classifications

• H02M1/12

  Arrangements for reducing harmonics from AC input or output · CPC title

• H02M5/458 Primary

  using semiconductor devices only · CPC title

• H02M7/53875 Primary

  with analogue control of three-phase output · CPC title

• H02J3/01

  Arrangements for reducing harmonics or ripples · CPC title

• H02M7/5395

  by pulse-width modulation · CPC title