2　Terms，Symbols and Codes

2.1　Terms

2.1.1　Capacitor element

The minimum component consisting of electrodes and dielectric of a capacitor unit.

2.1.2　Capacitor unit

An assembly of capacitor elements housed in a container（case），with terminals being led out.

2.1.3　Capacitor

A wording used in situations where the meaning of a"capacitor unit"or a"capacitor bank"is not required to be distinguished deliberately.

2.1.4　Assembling capacitor

An assembly of capacitor units housed in a container or an oil tank.

2.1.5　Self-healing capacitor

A capacitor provided self-healing function.

2.1.6　Capacitor bank

Multiple capacitors electrically connected together.

2.1.7　Installation of high voltage shunt capacitors

An installation comprising capacitors and associated primary and secondary electrical equipment，being parallel-connected in a three-phase AC power system at a nominal voltage over 1kV，and can be switched in/out independently.

2.1.8　Installation of low voltage shunt capacitors

An installation comprising LV capacitors and associated primary and secondary electrical equipment，being parallel-connected in a three-phase AC power system at a nominal voltage no higher than 1kV，and can be switched in/out independently.

2.1.9　Reactance ratio

The ratio of rated inductive reactance of reactors connected in series with a shunt capacitor installation to rated capacitive reactance of such capacitor installation，expressed in percentage.

2.1.10　Discharge device

Device or component installed inside or outside a capacitor，being intended to reduce the residual voltage resulting from disconnecting the capacitor from energized power system to a value below the specified limit within a given period of time.

2.1.11　Series section

A group of capacitor units connected in parallel.

2.1.12　Residual voltage

Residual voltage across the terminals of a capacitor unit or a capacitor bank when being disconnected from the energized power system.

2.1.13　Inrush transient current

The transient overcurrent that flows through a capacitor bank when it is connected into a power grid.

2.1.14　External fuses

A fuse disposed outside a capacitor unit and is series-connected with the latter，being intended to switch out the capacitor unit when faults occur in the unit.

2.1.15　Internal fuses

A fuse disposed inside a capacitor unit and is series-connected with the capacitor element，being intended to switch out the capacitor element when faults occur therein.

2.1.16　Bursting energy

The minimum energy that leads to the rupture of capacitor cases and bushings when internal breakdowns occur between the electrodes or between the electrode and the case.

2.1.17　Maximum reactive power of capacitor coordination for a discharge coil

The upper limit of capacity of a capacitor bank connected in parallel with a discharge coil which can reduce the residual voltage of the capacitor bank to a value below the specified limit within a given period of time.

2.1.18　Unbalance protection

The protection achieved by using the current or voltage difference between two parts inside a capacitor（bank）.

2.1.19　Ambient air temperature

Air temperature at the location where a capacitor is installed.

2.1.20　Cooling air temperature

Air temperature measured at the midpoint between two hottest points respectively on the cases of two capacitors within the hottest area of a capacitor bank under a stable condition.If there is only one capacitor，it means the air temperature measured at the point 0.1m distant from the hottest point of the case and at 2/3 height of the case.