FreqMeasurement#

Frequency measurements.

Common Parameters: u, name

Common Variables: f

BusFreq#

Bus frequency measurement. Outputs frequency in per unit value.

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

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	0.100	sec
fn	\(f_n\)	nominal frequency	60	Hz

Name	Symbol	Type	Description	Unit	Properties
L_y	\(L_{y}\)	State	State in lag transfer function		v_str
WO_x	\(WO_{x}\)	State	State in washout filter		v_str
WO_y	\(WO_{y}\)	Algeb	frequency deviation	p.u. (Hz)	v_str
f	\(f\)	Algeb	frequency output	p.u. (Hz)	v_str
a	\(a\)	ExtAlgeb
v	\(v\)	ExtAlgeb

Name	Symbol	Type	Initial Value
L_y	\(L_{y}\)	State	\(a - a_{0}\)
WO_x	\(WO_{x}\)	State	\(L_{y}\)
WO_y	\(WO_{y}\)	Algeb	\(0\)
f	\(f\)	Algeb	\(1\)
a	\(a\)	ExtAlgeb
v	\(v\)	ExtAlgeb

Name	Symbol	Type	RHS of Equation "T x' = f(x, y)"	T (LHS)
L_y	\(L_{y}\)	State	\(- L_{y} + a - a_{0}\)	\(T_f\)
WO_x	\(WO_{x}\)	State	\(L_{y} - WO_{x}\)	\(T_w\)

Name	Symbol	Type	RHS of Equation "0 = g(x, y)"
WO_y	\(WO_{y}\)	Algeb	\(- Tw WO_{y} + iwn \left(L_{y} - WO_{x}\right)\)
f	\(f\)	Algeb	\(WO_{y} - f + 1\)
a	\(a\)	ExtAlgeb	\(0\)
v	\(v\)	ExtAlgeb	\(0\)

Name	Symbol	Equation	Type
iwn	\(1/\omega_n\)	\(\frac{u}{2 \pi fn}\)	ConstService

Name	Symbol	Type	Info
L	\(L\)	Lag	digital filter
WO	\(WO\)	Washout	angle washout

Config Fields in [BusFreq]

Option	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)

Bus frequency and ROCOF measurement.

The ROCOF output variable is Wf_y.

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	0.100	sec
fn	\(f_n\)	nominal frequency	60	Hz
Tr	\(T_r\)	frequency washout time constant	0.100

Name	Symbol	Type	Description	Unit	Properties
L_y	\(L_{y}\)	State	State in lag transfer function		v_str
WO_x	\(WO_{x}\)	State	State in washout filter		v_str
Wf_x	\(Wf_{x}\)	State	State in washout filter		v_str
WO_y	\(WO_{y}\)	Algeb	frequency deviation	p.u. (Hz)	v_str
f	\(f\)	Algeb	frequency output	p.u. (Hz)	v_str
Wf_y	\(Wf_{y}\)	Algeb	Output of washout filter		v_str
a	\(a\)	ExtAlgeb
v	\(v\)	ExtAlgeb

Name	Symbol	Type	Initial Value
L_y	\(L_{y}\)	State	\(a - a_{0}\)
WO_x	\(WO_{x}\)	State	\(L_{y}\)
Wf_x	\(Wf_{x}\)	State	\(f\)
WO_y	\(WO_{y}\)	Algeb	\(0\)
f	\(f\)	Algeb	\(1\)
Wf_y	\(Wf_{y}\)	Algeb	\(0\)
a	\(a\)	ExtAlgeb
v	\(v\)	ExtAlgeb

Name	Symbol	Type	RHS of Equation "T x' = f(x, y)"	T (LHS)
L_y	\(L_{y}\)	State	\(- L_{y} + a - a_{0}\)	\(T_f\)
WO_x	\(WO_{x}\)	State	\(L_{y} - WO_{x}\)	\(T_w\)
Wf_x	\(Wf_{x}\)	State	\(- Wf_{x} + f\)	\(T_r\)

Name	Symbol	Type	RHS of Equation "0 = g(x, y)"
WO_y	\(WO_{y}\)	Algeb	\(- Tw WO_{y} + iwn \left(L_{y} - WO_{x}\right)\)
f	\(f\)	Algeb	\(WO_{y} - f + 1\)
Wf_y	\(Wf_{y}\)	Algeb	\(- Tr Wf_{y} - Wf_{x} + f\)
a	\(a\)	ExtAlgeb	\(0\)
v	\(v\)	ExtAlgeb	\(0\)

Name	Symbol	Equation	Type
iwn	\(1/\omega_n\)	\(\frac{u}{2 \pi fn}\)	ConstService

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	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)