Lumped-element Equivalent Circuit Modeling of District Heating Pipe in
Electromagnetic Transient Programs
Abstract
Electromagnetic transients program (EMTP) is widely used to analyse
transients in power systems. With the increasing interest in integrated
energy systems (IESs), it would be beneficial to extend the application
of EMTP to multi-physics transients in integrated electrical and heating
networks. In this paper, an accurate and efficient lumped-element
circuit model of the heating district pipe is developed in EMTP. The
pipe is split into segments using spatial discretisation. The
application of the numerical discretisation to the energy conservation
equation gives the discretised pipe equation which is expressed in the
form of a companion model of EMTP. In order to reduce the computational
effort, the time-varying terms in the admittance matrix of the companion
model of pipe are eliminated. The modification of the admittance matrix
is avoided. Furthermore, the internal nodes resulting from spatial
discretisation are eliminated, and the pipe model appears as a
lumped-element circuit with two external nodes. Case studies are carried
out to verify the accuracy and efficiency of the proposed lumped-element
circuit model of pipe. The implementation of the proposed pipe model in
the EMTP-type simulator enables the analysis of multi-physics transients
in a multi-carrier energy system.