In order to incorporate smart elements into distribution networks at ITELCA laboratories in Bogotá-Colombia, a Machine-to-Machine-based solution has been developed. This solution aids in the process of low-cost electrical fault location, which contributes to improving quality of service, particularly by shortening interruption time spans in mid-voltage grids. The implementation makes use of MQTT protocol with an intensive use of Internet of things (IoT) environment which guarantees the following properties within the automation process: Advanced reports and statistics, remote command execution on one or more units (groups of units), detailed monitoring of remote units and custom alarm mechanism and firmware upgrade on one or more units (groups of units). This kind of implementation is the first one in Colombia and it is able to automatically recover from an N-1 fault.
Recently, most electric power substations have adopted production control systems, such as SCADA systems, which communicate with field devices and remotely control processes from a computer screen. However, these systems together with protection measures and additional control actions (using protocol IEC61850) seem not to be enough to free substations of security attacks (e.g. virus, intruders, forgery or unauthorized data manipulation). This paper analyzes the main features of an electric power substation together with the aspects that might be significantly affected by cyber-attacks. The paper also presents the implementation of a specific security system (i.e. firewall-wise system) intended to protect a target distribution network.
Optical fiber has been used as typical physical transmission medium in Colombian high power substations for effective communication between substations and control centers. However, suitable transmissions of tele-protection services continues to be a challenging area in the electricalsupply sector since link stability as well as various performance tests suggest that link recurrence requirements still exhibit limitations when using Metroethernet networks in this context. At present, improvements have been achieved via proprietary protocols such as Mirrored Bits, which matches the performance of a tele-protection link transmission under normal operation conditions. However, this imposes commercial limitations on the Colombian electrical-supply sector since proprietary protocols hinder fair competition among manufacturers. This is the rationale behind conducting trials with precision time protocol as it is defined in IEEE 1588 standard. The main purpose is to validate whether, under real operation conditions, it is possible to substitute such tele-protection links via Metroethernet networks, yet considering a standard protocol that allows incorporating various pieces of equipment from different manufacturers into the system as well as providing common benefits derived from using this type of communication networks. The present work provides technical results obtained after conducting various simulated tele-trigger tests, including stress tests, where results-stability validation occurs through network-saturation simulations. These saturation conditions are achieved by incorporating additional traffic, which involves several switching events over link paths and permits validating tele-protection-response timing when specifically using IEEE 1588 precision time protocol. Based on the aforementioned reasons as well as on the resulting benefits, a series of laboratory tests have been defined in order to evaluate delay and availability on tele-protection services when transported over IP networks.
This paper describes the Danish legal framework for district cooling as an example of a model which so far has had limited success. A number of suggestions are analysed and discussed.
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