Electricity Asset Management Plan 2019-2029
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Vector Limited://
transformer data. The aim of this initiative is to take a more proactive approach to transformer management by using machine learning to predict faults before they happen. With secure access to bigger and smarter datasets, transformer maintenance works can be targeted with greater precision. Our replacement plan for power transformers is detailed in Section 5.
4.3.2 PRIMARY SWITCHGEAR Overview Our zone substation switchboards and circuit breaker assets comprise oil, SF 6
and air insulated equipment of varying ages
and brands. The arc-quenching/circuit interruption technology in our primary switchgear include oil, SF 6 -puffer and vacuum. The majority of the switchgear is 11 kV rated followed by 22 kV, 33 kV and 110 kV that generally corresponds to the network topology in that the higher the system voltage, the fewer the number of devices there are on the network. All SF6 and air insulated 33 kV, 22 kV and 11 kV switchgear utilise vacuum technology for current interruption. puffer circuit breaking technology and are all indoors except for two outdoor 110 kV CBs at Lichfield zone substation in the Waikato. Our 33 kV switchgear is a mix of outdoor and indoor types; outdoor switchgear is a mix of bulk oil type and new generation SF6 units; indoor 33 kV CBs are all SF 6 insulated. insulated. All 11 kV switchgear in zone substations are indoor units. Where two or more power transformers exist, the 11 kV switchgear comprises two or more bus-sections with incomer CBs to match the number of transformers. Population and Age Our Liverpool zone substation 110 kV switchgear is now 18 years old and the Hobson zone substation 110 kV switchgear was commissioned in 2013. Our 33 kV oil filled switchgear are 1960s and 1970s vintage. 22 kV SF 6 switchgear was introduced in the 1980s and 33 kV SF 6 switchgear in the late 1990s. The table and graph below provides key statistics of population and age of primary switchgear in Vector’s zone substations. All of the 110 kV switchgear are SF 6 insulated with SF 6 11 kV CBs are a mix of 11 kV oil filled and SF 6
No of 110 kV indoor SF 6
CBs
20
No of 110 kV outdoor SF 6
CBs
2
No of 33 kV outdoor SF 6
CBs
32
No of 33 kV indoor SF 6
CBs
149
No of 33 kV outdoor oil-filled CBs
85
No of 22 kV indoor SF 6
CBs
101
No of 11 kV indoor SF 6
and air insulated CBs
865
No of 11 kV indoor oil-filled CBs
428
Table 4-8 Key statistics for CBs for Primary Switchgear
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