TRANSMISSION &
DISTRIBUTION
A Division of Global Power
POWER SYSTEM STABILITY CALCULATION TRAINING
D3
DiSiltiPiilPt2
D
ay
3
-
D
ynam
i
c
Si
mu
l
a
ti
on
P
r
i
nc
i
p
l
es
P
ar
t

values can be determined if the values of all
values

can

be

determined

if

the

values

of

all

state variables, constants, and input
variables are
g
iven
g
 Input variables: Quantities for which values
are s
p
ecified at an
y
instant b

 Differential equations:
nem
n
DPP
dt
d
H




2
n
s
ync
dt
d
dt




 Constants
 Inertia: H
dt
 Damping: D
 Synchronous speed: ω
sync
= 1 p.u.
eBook for You

Calculate
I




















jXRjX
jB
jXR
e
jX
E
V
b

eBook for You
Exam
p
le of Power S
y
stem D
y
namic
8
CLASSIFICATION OF VARIABLES
pyy
Simulations

Sequence of Calculation:

Sequence

of

Calculation:
4. Calculate time derivatives

nem
n
HDPP
dt
d


 2/


Variables
eBook for You
Dynamic Simulation Arrays
11
CLASSIFICATION OF VARIABLES
Dynamic

Simulation

Arrays
 Algebraic Variables
eBook for You
Dynamic Simulation Arrays
12
CLASSIFICATION OF VARIABLES
Dynamic

Simulation

Arrays
 Algebraic Variables
eBook for You
Dynamic Simulation Arrays
13
CLASSIFICATION OF VARIABLES
Dynamic

Simulation




CON
(
J
)
CON (J+1)
()
eBook for You
Data Space Allocation
15
CLASSIFICATION OF VARIABLES
Data

Space

Allocation

Th PSS®E di f th l t l

Th
e
PSS®E
co
di
ng
f
or
th
e

(
L+1
)
eBook for You
Data Space Allocation
16
CLASSIFICATION OF VARIABLES
Data

Space

Allocation
eBook for You
17
DYNAMIC SIMULATION
SEQUENCE
SEQUENCE
eBook for You
Overall Flow Chart
18
DYNAMIC SIMULATION SEQUENCE
Overall

Flow

Chart
 Logic required to inform PSS®E of the
differential equations is provided by two
libraries of subroutines:
 Handling models that involve state variables and

Dynamic Simulation Basic Flow
20
DYNAMIC SIMULATION SEQUENCE
Dynamic

Simulation

Basic

Flow
eBook for You
Subroutines TBLCNC and CONEC
21
DYNAMIC SIMULATION SEQUENCE
Subroutines

TBLCNC

and

CONEC
 Responsible for equipment models
involving state variables and differential
involving

state

variables

and


values

of

all algebraic values of the state variable
time derivatives
 TBLCNC: responsible for machines and
their control systems
 CONEC: responsible for all other models
eBook for You
Subroutines TBLCNT and CONET
22
DYNAMIC SIMULATION SEQUENCE
Subroutines

TBLCNT

and

CONET
 Responsible for equipment models in
which there is a purely algebraic
which

there

is

a

ppqy
determined solely by network quantities,
such as relays and monitoring models
 Principle equipment: shunt load devices
(reactors), relays and meters
eBook for You
Subroutines TBLCNT and CONET
23
DYNAMIC SIMULATION SEQUENCE
Subroutines

TBLCNT

and

CONET
 Responsible for equipment models in
which there is a purely algebraic
which

there

is

a

purely

algebraic


eBook for You
Dynamic Simulation Control Flags
24
DYNAMIC SIMULATION SEQUENCE
Dynamic

Simulation

Control

Flags

MODE

MODE
 1: Initialization. Calculate initial condition values of
all state and algebraic variables
 2: The model must make all computations needed
to place time derivatives into the DSTATE array
(stabilizers excitation limiters )
(stabilizers
,
excitation

limiters
,…
)
 3: Computation of output values of generator
source currents, exciter field voltages, turbine
mechanical powers, stabilizer outputs, excitation


MODE

MODE
 1: Initialization. Calculate initial condition values of
all state and algebraic variables
 2: The model must make all computations needed
to place time derivatives into the DSTATE array
(stabilizers excitation limiters )
(stabilizers
,
excitation

limiters
,…
)
 3: Computation of output values of generator
source currents, exciter field voltages, turbine
mechanical powers, stabilizer outputs, excitation
limiter outputs

4: Apply special calculations in initialization of

4:

Apply

special

calculations