Unison's Mesh Radio Network

The mesh radio network Unison has installed across its three network regions has shortened restoration times, helped defer capital spending and improved staff safety.

The communication system is a key element of the firm’s five-year roll-out of smart devices across its network.

This Silver Spring Networks (SSN) Generation Four (Gen4) mesh radio network consists of 283 bridge radios and 94 repeaters. Unison was the first company in the world to install and commission Gen4 bridge radios and its system is now the largest SSN distribution automation network in Australasia.

The mesh network now provides faster and more reliable communications between the smart devices and the Supervisory Control and Data Acquisition (SCADA) system in the Unison Control Room in Hastings.

That means Unison’s 110,000 customers – in Hawke’s Bay, Taupo and Rotorua – are benefitting from faster restoration of supply in the event of a fault.

The communications network delivers a wealth of information from smart devices in the field, enabling Unison’s network controllers to more accurately pinpoint the location of the fault and then remotely reconfigure parts of the network to restore supply to as many consumers as possible. 

At the same time, field crews can be dispatched promptly to the area and can then carry out repairs straight away, rather than first spending time manually switching circuits back on to repower homes and businesses.

The SSN Gen4 mesh radio network was selected after extensive testing due to its speed, capacity and reliability. It also enables a range of smart grid applications including fast transfer schemes and remote engineering access.

Fast transfer schemes automatically transfer loads between zone substations or feeders, using remote controlled switches which are fitted with mesh radios.

Unison installed two of the automated switches on a feeder between its Camberley and Irongate zone substations in Hastings to help meet peak winter loads at Camberley.

The company says the scheme was successfully utilised four times in the past financial year. It deferred a potential $2 million transformer upgrade at the Camberley zone substation – which also supplies the Hawke’s Bay Regional Hospital. The two switches were installed for only $50,000.

Unison says another advantage the mesh network has delivered is remote engineering access to the smart devices on the network. Traditionally a technician would have to physically download an event log from an automated recloser or remote control switch, Unison staff can now do that remotely.

The company says that has eliminated the previous time lag in gathering the data, so fault diagnostics and corrections can progress faster. It has also increased employee safety by reducing travel and avoiding technicians coming into close proximity with live conductors while also working at heights. 

Unison says the mesh network can eventually support other smart grid applications such as smart meters and the control of street lighting.

Mesh radio networks are also self-healing and self-forming. The throughput of the network improves as additional radios are added and Unison says its network capability should continue to grow.

The Innovation in Energy award category is sponsored by Gentrack