Page 152 - UKZN Proceedings of the Conference Report

electrodes underground (Ruffini 2013). Another material for electrode manufacturing which is a lower risk compared to pure copper is copper-clad steel (Naidoo 2019).
The issue with the abovementioned measures is that they may only apply to the construction of new infrastructure, are in their infancy with regard to implementation, or come at a significant cost. A solution must be designed to work for existing HV towers and tower earthing electrodes. Theft can be reduced significantly if action is taken quickly on reported activity.
This proposal therefore discusses an alternative that monitors towers in real time in high-risk areas. A high-risk area is one where towers are highly susceptible to steel member and/or electrode theft. When theft is detected a localised alarm is triggered and an alert is transmitted to the local authorities, alerting them to the potential theft. Even if the authorities are unable to prevent the theft or apprehend the criminals, the utility will inspect the tower and do a risk assessment. This could save money by preventing an unscheduled interruption of supply and could also protect the public, both materially and physically.
Proposed specifications
To achieve the monitoring of the tower against theft and earth electrode degradation, the following functional specifications were compiled. These were in addition to non-functional specifications that included ensuring that the device remained small and compact to both reduce cost and remain inconspicuous.
Functional specifications
• The device is to detect, and alert, if the tower steel members are being cut with an angle grinder.
• The device should detect if the tower earthing electrode has been stolen.
• The device is to be powered by a solar panel-battery combination.
• The device should be able to function for at least 3 days without sunlight.
• When an event is detected, the status of the device should change.
• The device should not be triggered by false alarms.
• The device is to be enclosed in a suitably IP (IP66)-rated
housing (Bohn 2013).
• The device must be designed such that it can be
mounted onto the HV tower.
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Solar Panel
Figure 2: Proposed block diagram design of the HV tower theft detection and monitoring tool
Charge Controller
Battery
Status Indicator
angle grinder threat detection unit
Processing unit
Communication to Control room
hv tower earth footing Monitoring unit