FreqMeasurement#

Frequency measurements.

Common Parameters: u, name

Common Variables: f

Available models: BusFreq, BusROCOF

BusFreq#

Bus frequency measurement. Outputs frequency in per unit value.

The bus frequency output variable is f. The frequency deviation variable is WO_y.

Parameters#

Name

Symbol

Description

Default

Unit

Properties

idx

unique device idx

u

\(u\)

connection status

1

bool

name

device name

bus

bus idx

mandatory

Tf

\(T_f\)

input digital filter time const

0.020

sec

Tw

\(T_w\)

washout time const

0.020

sec

fn

\(f_n\)

nominal frequency

60

Hz

Variables#

Name

Symbol

Type

Description

Unit

Properties

L_y

\(y_{L}\)

State

State in lag transfer function

v_str

WO_x

\(x'_{WO}\)

State

State in washout filter

v_str

WO_y

\(y_{WO}\)

Algeb

frequency deviation

p.u. (Hz)

v_str

f

\(f\)

Algeb

frequency output

p.u. (Hz)

v_str

a

\(\theta\)

ExtAlgeb

v

\(V\)

ExtAlgeb

Initialization Equations#

Name

Symbol

Type

Initial Value

L_y

\(y_{L}\)

State

\(\theta - \theta_{0}\)

WO_x

\(x'_{WO}\)

State

\(y_{L}\)

WO_y

\(y_{WO}\)

Algeb

\(0\)

f

\(f\)

Algeb

\(1\)

a

\(\theta\)

ExtAlgeb

v

\(V\)

ExtAlgeb

Differential Equations#

Name

Symbol

Type

RHS of Equation "T x' = f(x, y)"

T (LHS)

L_y

\(y_{L}\)

State

\(\theta - \theta_{0} - y_{L}\)

\(T_f\)

WO_x

\(x'_{WO}\)

State

\(- x'_{WO} + y_{L}\)

\(T_w\)

Algebraic Equations#

Name

Symbol

Type

RHS of Equation "0 = g(x, y)"

WO_y

\(y_{WO}\)

Algeb

\(1/\omega_{n} \left(- x'_{WO} + y_{L}\right) - T_{w} y_{WO}\)

f

\(f\)

Algeb

\(- f + y_{WO} + 1\)

a

\(\theta\)

ExtAlgeb

\(0\)

v

\(V\)

ExtAlgeb

\(0\)

Services#

Name

Symbol

Equation

Type

iwn

\(1/\omega_n\)

\(\frac{u}{2 \pi f_{n}}\)

ConstService

Blocks#

Name

Symbol

Type

Info

L

\(L\)

Lag

digital filter

WO

\(WO\)

Washout

angle washout

Config Fields in [BusFreq]

Option

Symbol

Value

Info

Accepted values

allow_adjust

1

allow adjusting upper or lower limits

(0, 1)

adjust_lower

0

adjust lower limit

(0, 1)

adjust_upper

1

adjust upper limit

(0, 1)

BusROCOF#

Bus frequency and ROCOF measurement.

The ROCOF output variable is Wf_y.

Parameters#

Name

Symbol

Description

Default

Unit

Properties

idx

unique device idx

u

\(u\)

connection status

1

bool

name

device name

bus

bus idx

mandatory

Tf

\(T_f\)

input digital filter time const

0.020

sec

Tw

\(T_w\)

washout time const

0.020

sec

fn

\(f_n\)

nominal frequency

60

Hz

Tr

\(T_r\)

frequency washout time constant

0.100

Variables#

Name

Symbol

Type

Description

Unit

Properties

L_y

\(y_{L}\)

State

State in lag transfer function

v_str

WO_x

\(x'_{WO}\)

State

State in washout filter

v_str

Wf_x

\(x'_{Wf}\)

State

State in washout filter

v_str

WO_y

\(y_{WO}\)

Algeb

frequency deviation

p.u. (Hz)

v_str

f

\(f\)

Algeb

frequency output

p.u. (Hz)

v_str

Wf_y

\(y_{Wf}\)

Algeb

Output of washout filter

v_str

a

\(\theta\)

ExtAlgeb

v

\(V\)

ExtAlgeb

Initialization Equations#

Name

Symbol

Type

Initial Value

L_y

\(y_{L}\)

State

\(\theta - \theta_{0}\)

WO_x

\(x'_{WO}\)

State

\(y_{L}\)

Wf_x

\(x'_{Wf}\)

State

\(f\)

WO_y

\(y_{WO}\)

Algeb

\(0\)

f

\(f\)

Algeb

\(1\)

Wf_y

\(y_{Wf}\)

Algeb

\(0\)

a

\(\theta\)

ExtAlgeb

v

\(V\)

ExtAlgeb

Differential Equations#

Name

Symbol

Type

RHS of Equation "T x' = f(x, y)"

T (LHS)

L_y

\(y_{L}\)

State

\(\theta - \theta_{0} - y_{L}\)

\(T_f\)

WO_x

\(x'_{WO}\)

State

\(- x'_{WO} + y_{L}\)

\(T_w\)

Wf_x

\(x'_{Wf}\)

State

\(f - x'_{Wf}\)

\(T_r\)

Algebraic Equations#

Name

Symbol

Type

RHS of Equation "0 = g(x, y)"

WO_y

\(y_{WO}\)

Algeb

\(1/\omega_{n} \left(- x'_{WO} + y_{L}\right) - T_{w} y_{WO}\)

f

\(f\)

Algeb

\(- f + y_{WO} + 1\)

Wf_y

\(y_{Wf}\)

Algeb

\(- T_{r} y_{Wf} + f - x'_{Wf}\)

a

\(\theta\)

ExtAlgeb

\(0\)

v

\(V\)

ExtAlgeb

\(0\)

Services#

Name

Symbol

Equation

Type

iwn

\(1/\omega_n\)

\(\frac{u}{2 \pi f_{n}}\)

ConstService

Blocks#

Name

Symbol

Type

Info

L

\(L\)

Lag

digital filter

WO

\(WO\)

Washout

angle washout

Wf

\(Wf\)

Washout

frequency washout yielding ROCOF

Config Fields in [BusROCOF]

Option

Symbol

Value

Info

Accepted values

allow_adjust

1

allow adjusting upper or lower limits

(0, 1)

adjust_lower

0

adjust lower limit

(0, 1)

adjust_upper

1

adjust upper limit

(0, 1)