US 2017/0317574 A1Published application

Sub-module distributed control method, device and system

AssigneesNr Electric Co., Ltd, Nr Engineering Co., Ltd

InventorsJiudong DING, Jie TIAN, Yunlong DONG, Haiying LI, Dongming CAO, Haibin LIU, Yu LU

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Abstract

A submodule distributed control method, device and system are provided. Submodules of each bridge arm are grouped. Each group corresponds to one valve based controller. An upper-level control device calculates a weight of each group according to a bridge arm current, an average voltage of normal submodules in each group, and the number of the normal submodules in each group; calculates, according to the number of submodules to be input in a corresponding bridge arm, the number of submodules being input in each group and delivers the number to the valve based controller. The valve based controller operates according to a voltage balancing policy and a gating method that are provided in the prior art.

Claims8

Dependent claims

A submodule distributed control method, wherein all submodules of each bridge arm of a converter valve are grouped into M groups, M being ≧1, all the submodules comprise faulty submodules and normal submodules, the respective submodules in each group are equal or unequal in number, the normal submodules in each group are allowed to dynamically change in number, each group corresponds to one valve based controller, each valve based controller separately operates, an upper-level controller delivers the number of input submodules to the valve based controller, and the number of input submodules is calculated as follows:

(1) finding, by each valve based controller, an average voltage Ūi of the normal submodules administered by the valve based controller, counting the number Niok of the normal submodules, and sending the average voltage and the number to the upper-level controller;
(2) acquiring, by the upper-level controller, a bridge arm current Iarm and determining a direction;
(3) solving, by the upper-level controller, a weight Bi of each administered valve based controller according to the average voltage Ūi of the normal submodules administered by each valve based controller, the number Niok of the normal submodules, and the direction of the bridge arm current, where when the bridge arm current is in a charging direction,
B
i
=
B
i
p
=
N
i
ok

U
i
∑
i
=
1
M


(
N
i
ok

U
i
)
,
and when the bridge arm current is in a discharging direction,
B
i
=
B
i
n
=
U
_
i

N
i
ok
∑
i
=
1
M


(
U
_
i

N
i
ok
)
;
and
(4) calculating, by the upper-level controller according to the total number Ntotalon of the submodules to be input in a corresponding bridge arm and the weight Bi of each valve based controller, the number Nion=round (Bi Ntotalon) of the submodules being input in each valve based controller, where round is a rounding function.

63 more elements

A submodule distributed control device, comprising a direction determination unit, a weight solution unit, a selection switch unit, a bridge arm input calculation unit, and a valve based controller input calculation unit, wherein

the direction determination unit is configured to determine a direction according to the acquired bridge arm current Iarm;
the weight solution unit is configured to solve a weight Bi of each administered valve based controller according to an average voltage Ūi of normal submodules administered by each valve based controller, the number Niok of the normal submodules, and the direction of the bridge arm current, where when the bridge arm current is in a charging direction,
B
i
=
B
i
p
=
N
i
ok

U
i
∑
i
=
1
M


(
N
i
ok

U
i
)
,
and when the bridge arm current is in a discharging direction,
B
i
=
B
i
n
=
U
_
i

N
i
ok
∑
i
=
1
M


(
U
_
i

N
i
ok
)
;
the selection switch unit is configured to select the weight Bi of the administered valve based controller according to a determination result of the direction determination unit, and output the weight to the valve based controller input calculation unit;
and
the valve based controller input calculation unit is configured to calculate, according to the weight Bi and the total number Ntotalon, calculated by the bridge arm input calculation unit, of the submodules to be input in a corresponding bridge arm, the number Nion=round (Bi Ntotalon) of the submodules being input in each valve based controller, where round is a rounding function.

63 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/528,100Filed 28 Oct 2015
Priority: CN 201410768743.311 Dec 2014
Published: 2 Nov 2017
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

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