Electric power system voltage monitoring and control with energy packets

Patent metadata

Field	Value
Publication number	US-11035891-B1
Application number	US-202016811129-A
Country	US
Kind code	B1
Filing date	Mar 6, 2020
Priority date	Mar 6, 2020
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

Electric power system voltage control and voltage stability may be calculated using energy packets. Sets of negative energy packet sets normalized by a set of positive and negative energy packet sets may be used for voltage control by adding or removing capacitive units. Energy packet voltage indicators may be calculated using energy packets, and used to determine voltage stability. Control actions may be taken depending on the determined voltage stability.

First claim

What is claimed is:

1. A device for electric power system voltage control, comprising:
a stimulus interface for receiving electric power delivery system signals at a point and providing current and voltage measurements;
an energy packet calculator in communication with the stimulus interface to calculate energy packets over predetermined time interval lengths passing through the point by:
calculating products of the current measurements and the voltage measurements obtained over a time interval of the predetermined time interval length;
calculating a time interval power as a sum of the calculated products of the current and voltage measurements over the time interval; and,
calculating an energy packet value for the time interval as a numerical integration of the product of instantaneous voltage and current measurements over that time interval; and,

a voltage controller in communication with the energy packet calculator to:
calculate negative energy packet sets;
normalize the negative energy packet sets;
compare the normalized negative energy packet sets against a threshold; and
when the normalized energy packet sets exceeds the threshold for a predetermined time, initiate a control action.

2. The device of claim 1 , wherein the energy packet calculator is configured to calculate the energy packet value as:

ɛ
⁡

[
n
]

=

T
s

⁢

∑

m
=

M
⁡

(

n
-
1

)

+
1

Mn

⁢

⁢

v
⁡

[
m
]

⁢

i
⁡

[
m
]

where:
ε[n] represents the energy packet value for sample n;
T s represents the data sample period;
M represents a factor for downsampling;
v[m] represents a voltage value at sample m; and,
i[m] represents a current value at sample m.

3. The device of claim 1 , wherein the energy packet calculator is configured to calculate the energy packet value as:

ɛ
+

⁡

[
n
]

=

T
s

⁢

∑

m
=

M
⁡

(

n
-
1

)

+
1

Mn

⁢

⁢

{

v
⁡

[
m
]

⁢

i
⁡

[
m
]

if
⁢

:

⁢

⁢

v
⁡

[
m
]

⁢

i
⁡

[
m
]

>
0

0

otherwise

⁢

⁢

ɛ
-

⁡

[
n
]

=

Assignees

• Schweitzer Engineering Lab Inc

Inventors

• Schweitzer Iii Edmund O
• Zweigle Gregary C
• Blood Ellery A

Classifications

• G06Q50/06 Primary

  Energy or water supply · CPC title

• G01R21/133

  by using digital technique · CPC title

• G01R21/06 Primary

  by measuring current and voltage (G01R21/08 - G01R21/133 take precedence) · CPC title

• G01R19/2513

  Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging · CPC title