All high and extra-high voltage substations are the subject of several files:
"Role and structure
;
"Constructional provisions
;
"Construction and equipment
;
"Control and monitoring systems
;
"Metal-clad substations (PSEM)
;
Over the past thirty years, control and operation systems at high and extra-high voltage (HVB) substations on the French power grid have undergone a number of changes, including two major technological developments.
In addition to describing the generic design principles, this dossier gives a history of these developments since the first electromechanical control stage, and then describes in detail the static control stages (the most widespread in existing installations) and the digital control stages (which are now the standard on offer from suppliers).
Definition of electrical voltage levels
An earlier standard used the designations THT (400, 225 and 150 kV), HT (90, 63 kV) and MT (20 kV), which can still be found in some texts.
Today, UTE C18-510 defines the range of electrical voltages encountered on networks as follows:
HV, divided into HVB (voltages above 50,000 V (or 50 kV) alternating current) and HTA (voltages between 50,000 and 1,000 V alternating current);
LV: voltage below 1,000 V AC.
The French electricity transmission network includes facilities at levels HTB3 (400 kV), HTB2 (225 or 150 kV) and HTB1 (90 or 63 kV).
The HTA voltage level (typically 20 kV) is reserved for electrical distribution networks, which are not the subject of this dossier.
The LV voltage range referred to in this dossier exclusively includes the control circuits of HVB substations.