Lumped load (static model)#

This block is an electrical load, represented in calculationsby a variable shunt resistance depending on the effective valueand frequency of the voltage in the connection node. The valueof this resistance is calculated using the following formula (1) :

(1)#\[ Z(U,\Delta f)\:=\:R(U,\Delta f)\:+j X(U,\Delta f)\:=\:\frac{U^2}{P(U,\Delta f)}\:+\:j\cdot\:\frac{U^2}{Q(U,\Delta f)} \]

where

\(U\) - voltage in the load node, [kV];

\( P\left(U,∆f\right)\) и \( Q\left(U,∆f\right)\) - dependence of active ([MW])and reactive ([Mvar]) powers consumed by the load on the effective value andfrequency deviation of the voltage in the connection node.These dependencies are determined in accordance with the following formulas (2):

\[ P(U,\Delta f)\:=\:P_{ном}\:\cdot\:(a_{0}\:+\:a_{1}\:\cdot\:\frac{U}{U_{ном}}\:+\:a_{2}\:\cdot\:\frac{U}{U_{ном}}^2\:+\:K_{P}\:\cdot\:\frac{f\:-\:f_{ном}}{f_{ном}}); \]

(2)#\[ Q(U,\Delta f)\:=\:Q_{ном}\:\cdot\:(b_{0}\:+\:b_{1}\:\cdot\:\frac{U}{U_{ном}}\:+\:b_{2}\:\cdot\:\frac{U}{U_{ном}}^2\:+\:K_{Q}\:\cdot\:\frac{f\:-\:f_{ном}}{f_{ном}}) \]

where

\(P_{rat}\) и \(Q_{rat}\) rated values of active ([MW]) andreactive ([Mvar]) powers;

\(f\) - frequency value in the load connection node, [Hz];

\(f_{rat}\) - rated value of frequency, assumed to be 50 [Hz];

\(a_{0},a_{1},a_{2}\) - coefficients that take into account ratios betweendifferent types of active load;

\(b_{0},b_{1},b_{2}\) - coefficients that take into account ratios between different types of reactive load;

\(K_{P}\) и \(K_{Q}\) - coefficients that take into account the regulation coefficient of active reactive loads by frequency.

This model also contains typical static load characteristics,which are activated by selecting the appropriate field. In this case,the program will independently set the required coefficient valuesbased on the entered rated voltage and the ratio of the load nodevoltage to the rated voltage. The values of the typical characteristiccoefficients are given in the table :

Static characteristic type		\(a_0\)	\(a_1\)	\(a_2\)	\(K_P\)	\(b_0\)	\(b_1\)	\(b_2\)	\(K_Q\)
\( U_{rat}\le 35kV\)	\( \mathrm{0,815}\le \frac{U}{U_{rat}}\le 1.2\)	0.83	-0.3	0.47	1.1	4.9	-10.1	6.2	-1.5
	\( \mathrm{0,815}<\frac{U}{U_{rat}}\)					0.657	0.158	0	-1.5
	\( \frac{U}{U_{rat}}<1.2\)					1.708	0	0	-1.5
110kV \( \le U_{rat}\le 220kV\)	\( \mathrm{0,815}\le \frac{U}{U_{rat}}\le 1.2\)					3.7	-7	4.3	-1.5
	\( \mathrm{0,815}<\frac{U}{U_{rat}}\)					0.721	0.158	0	-1.5
	\( \frac{U}{U_{rat}}<1.2\)					1.49	0	0	-1.5
\( U_{rat}\ge 330kV\)	\( U=U_{rat}=330kV\)	1	0	0	0	1	0	0	0

1. Properties#

Property	Default value	Description	Units of measurement
Rated active power	10.0	–	MW
Rated reactive power	5.0	–	Mvar
Rated voltage	10.0	–	kV
Use predefined coefficients	On	–	–
a\(_0\) constant	0.83	Available, when `Use predefined coefficients` - `Off`	–
a\(_1\) constant	-0.3	Available, when `Use predefined coefficients` - `Off`	–
a\(_2\) constant	0.47	Available, when `Use predefined coefficients` - `Off`	–
K\(_P\) constant	1.1	Available, when `Use predefined coefficients` - `Off`	–
b\(_0\) constant	4.9	Available, when `Use predefined coefficients` - `Off`	–
b\(_1\) constant	-10.1	Available, when `Use predefined coefficients` - `Off`	–
b\(_2\) constant	6.2	Available, when `Use predefined coefficients` - `Off`	–
K\(_Q\) constant	-1.5	Available, when `Use predefined coefficients` - `Off`	–
Rated frequency	50.0	–	Hz

2. Inputs and outputs#

Parameters	Input/Output	Description	Units of measurement	Port type
Input	Input	–	–	Electrocity

In order to see the connection capabilities of the block, you need to go to page Description of block ports