BS EN 61975:2010 pdf download

BS EN 61975:2010 pdf download.High-voltage direct current(HVDC) installations – System tests.
d) converter transformers;
a) thynstor valves and cooling system;
t) station auxiliary service:
g) fire protection system;
Ii) a.c. and d.c. protection systems:
I) control system;
j) d.c. line or cable (fo open line test):
k) sequence of event recorder:
I) alarm system:
m) transient fault recorders
Prior to the converter tests, detailed procedures and plans should be prepared As the tests may involve some disturbance or increased risk to the connected a.c. systems, the operators of the systems should be consulted.
5.2 Converter unit test
5.2.1 Purpose of test
The test verities that at the first energization of the converter unit the insulation voltage withstand is achieved, and checks that the electrical phasing Is correct.
5.2.2 T.st precondition
Test preconditions are the following:
a) All controls and protections associated with the high voltage equipment shall be verified and in service, A trip test shall be made shortly befoe high voltage energizing (see 5.6).
b) Monitoring instrumentation shall be connected and ready.
C) All clamp joints shall have been tightened and the insulators wiped clean.
d) The HVDC transmission line disconnect switch shall be opened and locked
a) All safety procedures shall have been carried out.
I) A final visual inspection of the hi9h voltage equipment shall be performed and the arrester counter numbers shall be recorded
g) The low voltage side of the valves shall be earthed.
5.2.3 Test procedure
5.2.3.1 Low voltage energizing
Test conditions are the following:
a) During the test, all the internal reference voltages in the controls and the firing pulses of the valve control unit (VCU) are monitored.
b) The test may be performed by applying 0,5 to 10 kV to the primary side or to the valve side of the converter transformers with all ttiyristors short.circuited except one or more thyristors in each valve.
C) An appropriate resistor or reactor may serve as a load on the d.c. side
d) Each single valve Is represented by a single thyristor level. During the low voltage energizing test, the valves are de-blocked and the converter is operating in normal or open line test mode.
NOTE An alternalive approach to verily the phasing 01 the convertef main circuit connections arid the Interconneclions to the converter transformers is a thorough viiual inspection 01 the InterconnectIon scheme and conpanson wm the relevant dooimenLation This win however include verfec.ation that the control Bends out a tiring puts. to th. correci thl,I’Istor
5.2.3.2 HIgh voltag. .n.rglzlng Test conditions are the following:
a) Energize the converter transformer with the valves blocked and check the electrical phasing through the control system.
b) Ensure that the converter transformer tap changers initially at highest position (lowest valve side voltage) and then are stepped to rated voltage.
C) Keep the transformer energized for a minimum of 6 h.
d) Record s.c. voltage, steady-state and inrush-current, and inspect the equipment for abnoa’nal sounds and corona discharge during the test.
5.2.33 Test acceptance criteria
The test acceptance criteria are the following:
a) No abnormal sound or corona discharge shall occur in the energized equipmenL
b) No protection shall operate improperly.
c) Parameters, such as voltage, should be as expected,
5.3 Energizing of reactive components
5.3.1 Individual energizing of reactive components
Reactive components, such as ac. filters, capacitor banks and shunt reactors are energized for the first time individually, Combined switching of these elements Is described in Clause 6.
5.3.2 Purpos. of test
Purposes of the test are the following:
a) to verify that proper voltage insulation is achieved.
b) to verify that the ac. filters, capacitor banks and shunt reactors are balanced between the three phases
C) to confirm the no-load currents and voltages of the protections. ii any.
5.3.3 Test precondition
Test preconditions are the following
a) All controls and protections (main and bacicup) associated with the high voltage equipment shall be verified and in service A trip test shall be made shortly before high voltage energizing.
b) AC filter tuning shall be completed.
c) AC filters and shunt capacitors shall have been balanced.
d) All clamp joints shall have been tightened and the insulators wiped clean.