Electricity Asset Management Plan 2019-2029
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Vector Limited://
our 11 kV overhead network. Of these units, 56 use Very High Frequency (VHF) radio for communications and the remainder use 2G cellular communications. For communication to distribution substations Vector uses commercial cellular 2G/3G networks. Distribution substations that are remote controllable is equipped with an IP based layer 3 wireless router. The Northern region legacy radio system is based on six (6) base stations and one repeater to cover most of the area. It is used for voice, data communication and demand side management applications. In the Auckland region, a similar radio network was installed which consists of two base stations and three repeaters and one zone substation and five distribution substations are connected to the master station via this radio network. Data and communications between the EOC and the communications modules on 11 kV network switches are via the Conitel protocol and VHF analogue radio. Population and Age The expected life for digital mobile radio equipment is about 10 years. This has now been reached and the equipment is planned to be replaced over the next five years. Condition and Health The Digital Mobile Radio (DMR) network is performing well given its age. To date there have been only very few failures. There are no systemic issues with the wireless 2G/3G routers but a hardware refresh will be required in the next three years. Furthermore, the 2G cellular network does not provide sufficient coverage and this will also drive an upgrade of the 2G network. The VHF radio system has reached its end of life and the Conitel protocol is obsolete and firmware and software cannot be updated. Intermediate protocol convertors are required and this has resulted in loss of information and loss of SCADA visibility in the EOC of the status of 11 kV switches. Strategy The network is continually adapted to meet Vector’s specific needs and this has resulted in the adoption and deployment of Ethernet and IP based communication technology. 2G and 3G will become redundant in the 2020s and Vector will migrate to 4G and 5G. The Auckland radio network is performing satisfactorily but will become obsolete and is to be retired in the next five years. The subtransmission supply between Albany GXP and Coatesville zone substation is prone to mutual coupling and erroneous tripping – this issue can be solved with unit differential protection but the installation of a fibre optic cable to this remote zone substation will be prohibitively expensive. In FY19/20 we will undertake the first installation of its kind in our network where we will use a digital micro wave link between zone substations for line differential protection to improve the reliability of the subtransmission to this rural area. The Zone Substation's Local Area Network (LAN) is able to communicate with the Vector Wide Area Network (WAN) by means of Routers. The Routers ensure that SCADA data traffic is prioritised and relayed across the Vector WAN to the appropriate destinations. Routers also use dynamic routing techniques to help to reduce network traffic. The substation LAN is based on a resilient optical ethernet architecture compliant to IEC 61850 Standards. Population and Age The routers in in our zone substations are the Cisco 2811 model for which Cisco has made an end-of-sale and end-of- life announcement in 2013. Hardware and software support for the Cisco 2811 ended in 2014. Cisco has stopped all support for the Cisco 2811 in November 2018. 4.8.3 NETWORK ROUTER REPLACEMENT PROGRAMME Overview
Condition and Health The population of Cisco 2811 routers is approaching end-of-life and is unsupported.
Strategy Our strategy is to undertake a programme of replacement of the Cisco 2811 routers with the new standard CGR2010 routers – see Section 5 for full details of the replacement programme. This programme of works will be coordinated with the replacement of Copper pilot cables with fibre optic communications channels.
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