The source text is from, or quoted from, Asignación de Responsabilidad de Pago de Instalaciones del SST y SCT, Análisis de los Comentarios y Sugerencias al Proyecto de Norma (Informe N° 0244-2008-GART). It's about energy generation and distribution. You'll find it here http://www2.osinerg.gob.pe/Resoluciones/pdf/2008/Informe-No....

This piece is from section 2.7.3 which talks about electrical paths between electricity generators and demand busbars - 'barras de demanda'. It's explained in a bit more detail here in section 3 https://www.coes.org.pe/DATAWEB2/2009/STR/VALWEB/P-022-2009....

Another example of 'barras de demanda' is found in this paper. Figure 11 shows busbars 10, 11 and 12 (noted as bus 10, bus 11 and bus 12) with their respective loads, and shows the graph of the relative voltages on these three busbars which are referred to as 'barras de demanda' in the title of the graph
https://www.researchgate.net/publication/275023777_CONTROL_D...

An example of demand busbars in English are shown here in Figure 5.23 with power flow calculations showing the voltage at the demand busbar in the text below the figure
http://files.hostgator.co.in/hostgator253199/file/electrical...

Another example with more references can be found in this paper about allocation of loss costs in distribution networks
https://bear.warrington.ufl.edu/centers/purc/docs/papers/040...

(There are also quite a few references to 'barrra' translating as busbar in the electricity field in the ProZ term search.)