Lumped load (dynamic model)#

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

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

where:

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

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

\[ P(U,\Delta f)\:=\:P_{ном}\:\cdot\:(a_{0}\:+\:a_{1}\:\cdot\:\frac{U}{U_{ном}}\:+\:a_{2}\:\cdot\:\frac{U}{U_{ном}}^2\:+\:a_{3}\:\cdot\:\frac{U}{U_{ном}}^3\:+\:a_{4}\:\cdot\:\frac{U}{U_{ном}}^4\:+\:K_{P}\:\cdot\:\frac{(f\:-\:f_{ном})}{f_{ном}}); \]

(2)#\[ Q(U,\Delta f)\:=\:Q_{ном}\:\cdot\:(b_{0}\:+\:b_{1}\:\cdot\:\frac{U}{U_{ном}}\:+\:b_{2}\:\cdot\:\frac{U}{U_{ном}}^2\:+\:b_{3}\:\cdot\:\frac{U}{U_{ном}}^3\:+\:b_{4}\:\cdot\:\frac{U}{U_{ном}}^4\:+\:K_{Q}\:\cdot\:\frac{(f\:-\:f_{ном})}{f_{ном}}) \]

where:

\(P_{rat}\) и \(Q_{rat}\) - nominal values of active [MW] and reactive [MVAr] powers;

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

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

\(a_{0},a_{1},a_{2},a_{3},a_{4}\) - coefficients that take into account ratios between different types of active load;

\(b_{0},b_{1},b_{2},b_{3},b_{4}\) - coefficients considering ratios between different types of reactive load;

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

This model is only applicable to the calculation of dynamic processes in electrical systems.

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	–	kW
a\(_0\) constant	0.55	–	–
a\(_1\) constant	-0.3	–	–
a\(_2\) constant	0.47	–	–
a\(_3\) constant	-0.22	–	–
a\(_4\) constant	0.5	–	–
K\(_P\) constant	1.1	–	–
b\(_0\) constant	2.9	–	–
b\(_1\) constant	-8.1	–	–
b\(_2\) constant	6.2	–	–
b\(_3\) constant	-4.2	–	–
b\(_4\) constant	3.2	–	–
K\(_Q\) constant	-1.5	–	–
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