The smart grid (SG) is a movement to bring the electrical power grid up to date so it can meet current and future requirements to fit customer needs. Disturbances in SG operation can originate from natural disasters, failures, human factors, terrorism, and so on. Outages and faults will cause serious problems and failures in the interconnected power systems, propagating into critical infrastructures such as nuclear industries, telecommunication systems, etc. Nuclear power plants (NPP) are an intrinsic part of the future smart grid. Therefore, it is of high priority to consider SG safety, mutual influence between NPP and SG, forecast possible accidents and failures of this interaction, and consider the strategies to avoid them.
TopIntroduction
There are following development trends in SG (Y. Saleem, et.al. 2019) such as:
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Implementation of Open Protocols: Open industry standard protocols are replacing vendor-specific proprietary communication protocols.
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Interconnected to Other Systems: Connections to business and administrative networks to obtain productivity improvements and mandated open access information sharing.
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Reliance on Public Information Systems: Increasing use of internet and public telecommunication systems the for portions of the control system, etc.
The SG always needs to be available, and locking the system during an emergency could cause safety issues and security issues.
The SG security objectives are confidentiality, integrity and availability. In most industries confidentiality and integrity have higher precedence over availability. In the electrical power system, electricity must always be available, so this is the most important security objective. Integrity is the next important security objective followed by confidentiality. Availability is the most important security objective.
Integrity is the next important security objective in the SG. The SG uses data collected by various sensors and agents. This data is used to monitor the current state of the electrical power system. Unauthorized medication of the data, or insertion of data from unknown sources can cause failures or damage in the electrical power system. The electricity in the power grid not only needs to always be available, but it also has to have quality. The quality of the electrical power will be dependent on the quality of the current state estimation in the power system (A. Basit, G. A. S. Sidhu, 2016).
One of the main concerns for SG is the connectivity, automation and tracking of large number of devices, which requires distributing monitoring, analysis and control through high speed, ubiquitous and two-way digital communications. It requires distributing automation of SG for such devices or “things”.
There are a lot of different types of influences between NPPs and SG, which stipulate NPP’s safety levels. These influences cause the change of state of each PG subsystem during its life cycle. The balance of influences is considered as a basis for the SG stability and NPP safety. The change of these influences could lead to a balance violation. In its turn these violations lead to the NPP and SG subsystem’s states changing. This chapter represents an approach for formalization of different types of influences between the NPP and SG. It helps to analyze the complex behavior of NPP and SG as a system of systems (SoS) and predict their safety levels considering the change of states.
The application of hybrid methods makes operator less dependent on information from instrumentation and control system (I&C). The illustrative example for the NPP reactor safety assessment is considered in this chapter.
TopBackground
A SG is comprised of four main subsystems (see Figure 1), power generation, power transmission, power distribution and power utilization.
Figure 1. Four main subsystems of smart grid
IoT technologies (W. Shu-wen, 2016) can be applied to all these subsystems and appears as a promising solution for enhancing them, making IoT a key element for SG. In the power generation area, IoT can be used for the monitoring and controlling of energy consumption, units, equipment, gas emissions and pollutants discharge, power use/production prediction, energy storage and power connection, as well as for managing distributed power plans, pumped storage, wind power, biomass power and photo-voltaic power plants. In the power transmission area, IoT can be used for the monitoring and control of transmission lines and substations, as well as for transmission tower protection. In the power distribution area, IoT can be used for distributed automation, as well as in the operations and equipment management. In the power utilization area, IoT can be used for smart homes, automatic meter reading, electric vehicle charging and discharging, for collecting information about home appliances energy consumption, power load controlling, energy efficiency monitoring and management, etc.