1. Cyber-Physical Systems for Enhancing the Global Sustainability
Prof. Mohammad Shahidehpour
Galvin Center for Electricity Innovation
Illinois Institute of Technology

2. Outline Introduction to Cyber-Physical Systems
Smart City as Cyber-Physical System
Cyber-Physical Operating States
Co-Simulation of Cyber-Physical Systems
Conclusions

3. What is a Cyber-Physical System?
A Cyber-physical system (CPS) is an engineering system in which information and communication technologies are coordinated to achieve an intimate integration of physical system dynamics.
Smart City, a typical case of CPS, consists of physical and cyber subsystems, which are dependent on each other for fulfilling their functionality.
In smart cities, CPS encompasses sensors that monitor power grid, water, waste water, natural gas flow, transportation, communication, and environmental conditions
CPS reduces consumptions, increase public safety, enhance global sustainability and improve individuals comfort.

4. Urbanization of Infrastructures as a CPS

5. Constrained Urban Mobility
Aging transportation infrastructures results in urban traffic congestion, significant economic losses and an increased number of traffic accidents.
The opportunity cost of an individual driver in traffic congestion is estimated at roughly $24 per hour of person travel.
In the year of 2014, drivers in Chicago cumulatively suffered over 302 million hours of travel delay with a total congestion cost of $7,248 million.
Congested road traffic is the main source of green gas emission.

6. Aging City Infrastructures
Aging infrastructures create significant challenges for most cities.
On average, up to 25% of the water entering a city’s water management and treatment system is lost through leaks in the water infrastructure.
According to the American Society of Civil Engineers, 60% of the six million miles of power distribution lines within the United States have surpassed their life expectancy of 50 years.
It is technically and economically challenging to update aging infrastructures.

7. Blackouts in Cyber Physical Systems
Time
Location 
Cyber Cause
Consequence
2003
 Northeast U.S.
Alarm system failure due to a software bug
50 million customers lost electricity
 Italy
Cascading failures of power and communication infrastructures
56 million people were affected
2007
 Arizona, U.S.
Unexpected activation of the load shedding program
100,000 customers lost 400 MW load
2008
 Florida, U.S.
Disabled relay protection during a diagnostic process
1 million customers lost 3,650 MW load
2011
Southwest U.S. 
Monitoring equipment failure at a substation
Around 2.7 million customers lost electricity
2015
Ukraine 
Remote cyber intrusions after the malware installation
Around 225,000 customers lost electricity
Massive Cyber power outages Arouse public awareness to enhance the role of cyber security in CPS.
Physical security: On Aug. 14, 2003, New York City was severely hit by a blackout resulting from cascading power failures, and its 8 million citizens suffered from prolonged power outages .

8. Smart City: CPS for Integrating Urban Infrastructures
The notion that technology will gradually replace the human workforce is real. Smart City will put the transition into perspective.
Smart city is an urban center that integrates interdependent infrastructures with a common goal of enabling certain social objectives.
Managing large cities for enhancing economics, reliability, resilience, security, and sustainability is one of the major CPS challenges .
Smart city as a CPS connects social capital and infrastructural objectives in order to address public mandates.

9. Operating States of CPS
Based on the CPS status corresponding to cyber and physical subsystems, all possible CPS operating conditions are divided into the four states:
Secure State. Both cyber and physical security are ensured.
Alert State. Physical security is maintained but cyber security is violated.
Emergency State. Cyber security is maintained but physical security is violated.
Extreme State. Cyber and physical security are violated simultaneously.

10. Interdependencies of CPS Subsystems
If the cyber subsystem suffers severe disruptions, system operators will have insufficient situational awareness.
They fail to observe complete operating condition of the physical subsystem, and fail to make timely decisions in emergency situations.
Disrupted Cyber Subsystem
Disrupted Physical Subsystem
Actual Condition
Estimation
State
Observed Condition

11. Typical CPS Incident
Topology preserving attack (TPA) is a specific type of false data injection, which could mask the topology change due to line outages that are caused by either physical disruptions or cyber incidents.
TPA forges power flow measurements of the disrupted lines and modifies load measurements at certain buses (if necessary) in order to preserve the state estimation results after line outages.
TPA impedes the detection of line outages, deteriorates the operating condition and causes an extended service disruption.

12. Decision-Making Simulation
Holistic CPS Security
CPS security necessitates a comprehensive strategy that protects smart city services from cyber threats.
The decision-making for holistic CPS security enhancement is a multi- player strategic game which involves three groups (planners, attackers, operators) taking actions in sequence.
Implementation
Decision-Making Simulation

13. Co-Simulation for CPS Operations
Cyber-physical co-simulation is conducted for identifying potential dynamics of CPS operations under selected contingencies.
Cyber-physical co-simulation retains the simulation processes in individual simulators and coordinate them under a common framework, while ensuring strict time synchronization and efficient data exchanges.
Quantitative indices are defined to measure the severity of CPS incidents and reflect the feasibility of coping with these contingencies.

14. Distributed Power Systems
A widespread adoption of DERs would drive and flourish distributed and controllable power systems (e.g., microgrids, nanogrids) in the near future and challenge the existing utility-based regulation models and policies.
These distributed power systems are expected to play an increasingly important role in extracting incremental values from DERs locally and improving power distribution system operations globally.

15. IoT: Internet of Things
As grid modernization continues, power distribution systems themselves become a platform for social and technological innovations to enhance the efficiency, reliability, resilience, and sustainability of electricity services.
Internet of things (IoT) plays the key part in filling the gap between control and monitoring applications and physical processes.
IoT is viewed as a set of innovative technologies that instill intelligence to almost any such thing and link them to interact with the physical world.

16. Microgrids to Energy Hubs
Microgrids represent a promising platform for integrating a multitude of local energy carriers as an energy hub, which intertwines the generation, conversion, storage and consumption of diverse energy resources.
In an energy hub, synergies among various forms of energy are realized for optimizing the use of onsite resources and improving the social welfare.

17. Cyber-Secure Energy Management
Both operation technologies and information technologies offer effective solutions for improving the ADN energy management performance.
The coordination of these technologies leads to a hierarchical framework that decentralizes decision making processes of the ADN energy management in a cyber- secure manner.

18. Blockchain as Cybersecurity Solution
Blockchain, a powerful tool to settle privacy and reliability concerns in IoT, can automate communications between microgrid master controllers in a cyber-secure manner.
Blockchain is a type of secure chronological database technology that maintains a continuously growing list of data records (i.e., blocks).
Smart contracts on blockchain make it possible to automate sophisticated interactions between energy hubs in a dependable and auditable way.
Energy hubs use blockchain to interact and collaborate without a central coordinator.
The decentralized nature of transactive energy management lends itself to a blockchain implementation aided by smart contracts, while SDN technologies are beneficial for managing on-site DERs within microgrids.
The information exchanged between any two MGMCs is secured by cryptography applied to blockchain and stored identically in MGMCs for creating a set of publicly auditable records.
Each microgrid needs to register with DSO in order to be authorized to participate in the transactive energy system.
The blockchain can be configured as permissioned with no requirements for an energy-intensive proof-of-work mining process (e.g., the process of digging out Bitcoins).
The corresponding lightweight consensus consumes less energy and computation resources for appending blocks to blockchain.

19. Interdependent Infrastructures in Smart City
Production,
Cooling,
Emissions Reduction
Water for
Power for Compressors, Storage, Control Systems
Fuel for Generators
Power for Pump
and Lift Stations,
Control Systems
Power for Switches
Heat
Power for Pumping Stations, Storage, Control Systems
Fuel for Generators, Lubricants
SCADA,
Communications
SCADA, Communications
Fuels, Lubricants
Water for Cooling
Fuel Transport,
Shipping
Fuel
Transport, Shipping
Power for
Signaling,
Switches
Water for Production, Cooling, Emissions Reduction
Water
Transpor-
tation
Oil
Telecom
Natural
Gas
Electric
Power