Lowering Installation Costs with High-Efficiency 410-470MHz Antenna for Smart Energy Substation Monitoring

Fueled by the climate crisis and the need for sustainable development, the energy transition has been characterized by the massive introduction of renewable energy sources and the decentralization of energy generation. Distribution System Operators (DSOs) across the world embrace this transition and already undertake meaningful actions to remain ahead of the foreseen challenges related to grid stability.

Substation monitoring is one of the key and indispensable actions to balance supply and demand of future energy systems. It allows DSOs to transition from a corrective-based implementation to a preventive-based energy distribution system. Such a predictive approach relies on a telecommunication system enabling the acquired data from substation assets to be wirelessly transmitted to a centralized management system running the necessary control algorithms.

The ultimate technical success of the telecommunication system relies partly on the quality of the radio link regulating the transfer of data and information. A critical element of this link is the antenna and its placement in- or on the substation.

Signal strength levels inside the substation are unpredictable because of a high variety in wall constructions and corresponding RF attenuations. Around the substation, the signal strength levels depend on the proximity of the cellular tower and its relative position with respect to the substation.

A roof-mounted omnidirectional outdoor antenna is therefore identified as the most optimum solution, especially in sparse networks, where the relatively low number of base stations results in bad network coverage. This is more pronounced in rural areas where cell-edge issues might become relevant. Poor connectivity in this case, can be mitigated by the use of a high efficiency outdoor antenna with an omni-directional radiation pattern, mounted on the roof of the substation. This approach increases the success rate of connecting reliably to surrounding base stations without extensive and time-consuming activities (like signal sniffing or base station localization) prior to antenna installation.

In urban areas with excellent radio coverage and risks of vandalism, an indoor antenna solution is preferred. Mounting the antenna inside the substation has profound implications for deployment costs. An indoor antenna solution eliminates the costs of maintenance and repair associated to vandalism and reduces antenna installation time and costs significantly. However, one of the challenges associated to indoor mount is wall attenuation, which varies greatly depending on the composition of the substation wall. To illustrate the previous point, an 18cm brick wall resulting in 3.5dB attenuation will require an indoor antenna with 80% percent efficiency to achieve the same link budget as an outdoor antenna with 36% efficiency under the same input power and radio settings, as shown in Figure 1.

A smart antenna installation strategy is therefore key to assure proper operation of the telecommunication system while minimizing deployment costs.

The AC94541 antenna offered by The Antenna Company is a versatile indoor/outdoor multiband antenna, developed to reduce antenna installation costs while providing excellent and reliable connectivity. Its high efficiency (see figure 2), ranging from 70-90% in the 410-470 MHz bands, increases the success rate of indoor mount. The associated benefits for DSOs are significant. As an example, a 20% success rate of indoor mounts on a basis of 40000 substations will result in about €1 million in savings, assuming an installation time of 1.5 hour per unit, hourly labor costs of €65 and €20 worth of dedicated outdoor accessories. This is in addition to the cost savings associated with the elimination of maintenance or repair resulting from vandalism. The total cost saving is estimated to exceed hundreds of thousands of euros for an antenna replacement rate of 200pcs/year over 10 years and expected repair time of 3 hours.

The weatherized design (IK10- and IP67-compliant) of the AC94541 antenna allows DSOs to reuse the same antenna when an outdoor installation is necessary. The mounting versatility, as shown in Figure 3, simplifies inventory management and provides DSOs with a more effective installation flow whereby indoor mount is investigated first, before outdoor mount is considered.

Figures for Article

Figure 1

Figure 2

Figure 3