Method for the operation of electrostatic precipitators

Patent metadata

Field	Value
Publication number	US-9325300-B2
Application number	US-201113701055-A
Country	US
Kind code	B2
Filing date	Jun 17, 2011
Priority date	Jun 18, 2010
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

The disclosure relates to a method for the scheduling and/or the operation of a system of at least two power supplies ( 11 ) providing DC pulses to a consumer ( 5 ), typically an electrostatic precipitator, wherein the power supplies ( 11 ) are energized by a common feeding ( 1 ). According to the proposed method one power supply ( 11 ) is defined to be the reference power supply, and the initial pulses of each further power supply ( 11 ) are shifted by controlled delays (δ Pri ) with respect to the pulses of the reference power supply so as to fill the gaps between the pulses of the reference power supply by the pulses of the further power supplies ( 11 ).

First claim

The invention claimed is:

1. A method for scheduling or operating a system comprising:
at least two power supplies providing DC pulses to a consumer, the consumer being an electrostatic precipitator operated in at least one bus section in pulsed mode and in at least one further bus section in continuous mode; and
a common feeding energising the at least two power supplies;
wherein one power supply is defined as a reference power supply, with initial pulses of each further power supply shifted by controlled delays from pulses of the reference power supply, to fill gaps between the pulses of the reference power supply with the pulses of the further power supplies.

2. The method according to claim 1 , wherein the reference power supply is the power supply with a largest pulse period.

3. The method according to claim 1 , wherein the consumer is an electrostatic precipitator operated in pulsed mode.

4. The method according to claim 1 , wherein the controlled delays are set to uniformly distribute the pulses of the further power supplies in the gaps between the pulses (pulse period) of the reference power supply, and, if the accumulated pulse width of all power supplies is smaller than the largest pulse period, the controlled delays are set so gaps between all pulses are equal, if the accumulated pulse width of all power supplies is equal to the largest pulse period, the controlled delays are set for no gaps between pulses, and if the accumulated pulse width of all power supplies is larger than the largest pulse period, the controlled delays are set so overlap length of each pulse is equal.

5. The method according to claim 1 , wherein the delays of the further power supplies are calculated sequentially using the following formula:

δ
Pri

=

k
⁢

Tp
r

-

∑

z
=
1

n

P
⁢

⁢
S

⁢

⁢

P
⁢

⁢

W

P
⁢

⁢
S
⁢

⁢
z

n

P
⁢

⁢
S

+

P
⁢

⁢

W

P
⁢

⁢
S
⁢

⁢
r

+

∑

z
≠
r

=
0

i
-
1

⁢

⁢

P
⁢

⁢

W

P
⁢

⁢
S
⁢

⁢
z

(
1
)

wherein δ Pri is controlled delay of power supply i, T Pr is pulse period of the reference power supply with the largest pulse period, n PS is the total number of power supplies in the system operated in pulsed mode, PW PSz is the pulse width of the power supply with index z, PW PSr is the pulse width of the reference power supply and k is running index incremented for each subsequent calculation of the controlled delay for subsequent power supply.

6. The method according to claim 5 , wherein in a first step, the power supply with the largest pulse period is se

Assignees

• Ranstad Per
• Linner Jörgen
• Biela Jürgen
• Soeiro Thiago Batista
• Alstom Technology Ltd

Inventors

• Ranstad Per
• Linner Jörgen
• Biela Jürgen
• Soeiro Thiago Batista

Classifications

• H03K3/36 Primary

  by the use, as active elements, of semiconductors, not otherwise provided for · CPC title

• H02M7/493

  the static converters being arranged for operation in parallel · CPC title

• H02M1/0043 Primary

  Converters switched with a phase shift, i.e. interleaved (non-isolated DC/DC converters H02M3/1586) · CPC title