Electricity Asset Management Plan 2019-2029
128
Vector Limited://
No of modern numerical transformer management systems
112
No of programmable logic controller transformer management systems
20
No of electro-mechanical transformer management systems
85
Table 4-23 Key statistics for Transformer Management Systems
Condition and Health Technical and spares support for older electro-mechanical systems is becoming a challenge and older PLC TMS are technically unsupported but are being kept in service through our maintenance programme. Strategy The strategy for this asset is described in EAA802 Transformer Management Systems. Because of the fact that there is no spares available for both the electro-mechanical population and there is no technical support for the PLC based systems, in order to maintain service levels and reduce the risk of loss of supply, a programme is in place to replace all electro-mechanical and PLC based TMS in the next five to six years. This programme is described in Section 5. As mentioned under the section on power transformers we are also preparing for a trial to implement dynamic ratings on a number of power transformers to extend the asset life and use of power transformers. If this trial is successful, the use of dynamic ratings as a tool to extend the life of power transformers will be rolled out further. The future energy network in which distributed generation is gaining mass and the expectations of customers for a reliable and resilient network of high quality increase, combined with regulatory requirements, leads to the power system becoming more complex. This requires network monitoring equipment that provides high speed monitoring of electrical parameters with a given number of seconds before and after a trigger event. About two decades ago Vector embarked on a programme to install power quality meters to improve its visibility of the performance of the electricity network. PQMs assess the quality of power, identify the causes of any problems and check the effectiveness of remedial measures. Power quality is defined by a group of performance attributes and the four main functions are: 4.7.3 POWER QUALITY METERS Overview
• • • •
Monitoring of harmonics;
Detections of voltage sags and swells;
Detection of transients; and
Electricity supply compliance checking
In addition, we utilise a power quality metering system as a check of energy consumption at GXPs as measured by revenue meters. PQM also assist with the analysis of faults and our fleet of PQMs provide data to a separate PQM server at the EOC. Population and Age The age of the PQM population is approaching 18 years. The table and graph below summarises the population and age profile of the PQM fleet.
No of PQMs in the Auckland region
101
No of PQMs in the Northern region
34
No of PQMs in the Lichfield area
10
Table 4-24 Key statistics for PQM
Made with FlippingBook - professional solution for displaying marketing and sales documents online