There is no need to reinvent the wheel
In every debate revolving around smart cities, the question of infra-structure is sure to come up. Infra-structure is the foundation of an ecosystem of functionally connected solutions capable of communicating and interacting with one another. Building such an infrastructure from scratch is possible, but the invest-ments would be astronomical. Mean-while, we only have to look at cities from a different perspective to see that they already have such an infra-structure. It is public lighting.
This seemingly elementary realisation is surprisingly logical. The most ingeniously elaborated network of fixed points cit-ies currently have is public lighting, which has a huge poten-tial for functionality enhancement. Accessibility, the regular distance between the lampposts, their standardised height, along with the mounting height of the lamps are important technical preconditions for building a smart city infrastruc-ture. In addition, if we take into account that the whole system can be controlled from a single location, together with the fact that the lamps and poles can be enhanced with additional functions, we find that that we already have a perfect basic infrastructure for building connectivity and IoT (Internet of Things) platforms for smart city modules.
A lamp that can see and hear
amps in standard lighting systems are currently powered by 230 V and they only operate at night. This technical solu-tion, however, does not allow us to use the lighting system outside of its normal operation hours. Let’s imagine replacing every lamp in a lighting system with smart lamps equipped with IoT nodes. Dimmable lamps will continue to produce light only at night or when visibility drops below a certain level; however, they will always run in a low-voltage mode. We thus gain a power supply where we can attach sensors and other technologies that can be integrated directly into the lamps. This simple modifi-cation will convert the lighting system into an infrastructure on which we can start building our smart city.
In a smart city concept, lamps can be turned into IoT nodes capa-ble of reading, measuring, accepting and transferring data. More importantly, this data will be stored, further processed, analysed and will always be available. In consequence, they not only give the user a real-time overview of a measured value, but they also create a structured database which provides the user with an in-depth insight into a particular issue, warns him about repeating events, and allows him to use predictive methods to estimate their development.
Parameters that might be relevant to cities include data on the concentration of pollen, dust or smog in the air, air temperature, traffic density, car park occupancy or waste container fullness. More sophisticated technologies such as SOS buttons, gunfire locators or crash sensors attached to the lamps or mounted on their poles may also contribute to the improvement of public safety. There is an inexhaustible array of options that will further expand depending on the requirements and types of sensors the future will bring. Decisive factors for their installation will include the applicability of the particular device and the parameters they will be able to measure in a smart city.
Monitoring and collecting data in itself would be far from interesting if we could not t share, store, analyse and evaluate the information online. This is another reason why public lighting provides the ideal conditions for a smart city infrastructure.
A platform capable of communicating
Monitoring and collecting data in itself would be far from inter-esting if we could not t share, store, analyse and evaluate the information online. This is another reason why public lighting provides the ideal conditions for a smart city infrastructure. We could transfer and share data using already known methods such as PowerLine, Bluetooth, external DALI, or ones that have not so far been put to such use in lighting system control that, however, have much potential. Data collection and data trans-fusion can also be implemented through standardised BigData hardware and systems, or by aggregating applications and systems capable of communicating with each other through the API. API can be understood as a universal language which allows systems and applications to communicate – that is, to exchange data – without having to integrate any additional hardware. This efficient interconnectedness of every function will lead to an open smart city platform which will allow us theoretically to integrate an endless number of systems and applications, and their relevance will again be defined only by how a smart city or any third party can use them.
Smart lighting in a smart city
Prerequisites and potential areas of application:
The lamp and its control unit form a compact whole and there is no need to install them separately.
The lamp ensures two-way communication with the control centre. The lamp is addressable; that is, a unique address is assigned to it which enables its identification.
It is possible to monitor a lamp’s state, its electrical ballast, failures, parameter settings, functionality etc.
The lamp is ready to operate 24/7, enabling the connection of additional sensors.
The angle of the lamp and the pole can also be monitored.
Each light is uniquely identified in the control system, and the control system automatically assigns the technical parameters of the lamp. A lamp is able to measure and communicate its following values: volta ge, current, power, energy consumption, power factor, temperature and the duration of lighting.
Lighting in a smart city
Urban lighting systems that have been renovated in the past years are currently controlled by dimming drivers. Some of these technologies can gradually switch on after detecting motion, or can reset the light intensity depending on cloudiness or astronomical time. Modul Lighting, which is already fully integrated into the CitySys IoT platform, can offer even more advanced ight-ing control functionalities and offer a more detailed overview of every single lamp, pole or switchboard forming part of a given lighting system. Every single lamp in a smart lighting system is addressable and can work with four basic scenarios: control, data, optimisation and maintenance. They can also provide information about them in a user-friendly way, giving a complex overview not only of the current condition of the lamps (whether they are operating or not) and all their measured parameters, but are also able to warn, for example, about repeated failures in a certain time period, or modify and preset various other scenar-ios such as defining how lamps should ‘behave’ in astronomical clock mode. Other functionalities that a CitySys lighting module enables include, among others:
- Monitoring the state of the control unit (in order/out of order)
- Measuring energy consumption, power, current, voltage and power factor
- Monitoring the state of the main circuit breaker (off/on)
- Controlling the state of the individual output line con tactors (off/on)
- Monitoring the state of the switchboard door (closed/open)
- Measuring light intensity (twilight sensor) i.e. what can be used with automatic switching
- Alarm signalling the switchboard door being open out side of maintenance time or in the case of unauthorised entry
- Setting up sms and email notification
- Creating virtual points, registering and signing off con nected devices
The platform’s openness also guarantees the integration of lighting devices from other manufacturers In smart cities, lighting is one of the areas that could not only reduce electricity costs but also has the potential to generate profits by selling surplus electricity.
It is clear from the above information that the entire concept of lightning as we know it at present is completely new to the smart city concept. Not only does it allow itself to use ad-vanced functionality, but from the infrastructure point of view it becomes a prerequisite for building the Smart City under current conditions. Existing public lighting networks and all other public lighting systems that occur in the near or distant future must now be seen as a fully-fledged infrastructure that can be enhanced with a number of additional functionalities such as measuring air and water quality, traffic density, monitoring and managing car-park occupancy, waste management, measuring visibility on urban roads, measuring the concentration of harmful substances (such as allergens or emissions) in the air etc. The result will be an intelligent, safe and efficient city with many new services for the citizen and opportunities for the city to achieve not only savings but also generate profits. Naturally, such pro-jects cannot be implemented overnight.
Public lighting switchboard in a smart city
A public lighting switchboard must include at least the following components:
- Control centre or PLC
- Three-phase electrometer
- Lighting branch circuit contactor
- Main switch
- Manual switchboard control (automatic, manual and off mode) Lighting branch circuit breakers
- Magnetic door contact
- Twilight sensor
- Unauthorized intrusion alarm (siren)
- Backup power supply for the control centre (PLC), alarm, switch contactors, magnetic contact
- Battery as a backup power supply
Author: Ing. Tomas Hutta, CitySys