IEEE Power & Energy Magazine - March/April 2018 - 61

The integration of renewable energy in the power system
is a real challenge for RTE with respect to both infrastructure
management and control of energy flow in real time.
✔ some dynamic simulations may be needed to study

transient stability. The analysis and remediation of
voltage collapse and interactions among automata
may become too complex for simulation as a series of
static load flows.
✔ With the increasing complexity of the grid management, the operator will need tools to find the best preventive and curative remedial actions. a specific tool
purely dedicated to safety assessment, being able to
simulate scheduled action logic and uncontrolled uncertainties with the greatest detail possible, achieves
the best vision of the risks and will be a cornerstone
of the future system. in stochastic optimization, such
a tool is called a strategy simulator. it allows one to assess the performance of strategies and compare them.
✔ another category of tools will help the operators or
even automate the decision process. They will be able
to make the required simplifications and test many
alternatives to determine the best operating decision
while the safety assessment tool will remain the touchstone that guarantees the conformity of the scheduled
actions to the risk framework.
✔ an additional uncertainty management scheme might
be needed between the contingencies whose occurrence
probability is very low (less than 0.01% per day) and the
historically modeled uncertainties whose occurrence
probability are rather high (more than 1% per day). indeed, while low-probability occurrences are handled
thanks to scenarios, high-probability occurrences are
handled with a learned probability distribution. some
uncertainties, for example, the primary reserve induced
flows, are difficult to model under both schemes. We
have explored robust security analysis where the risk
doctrine requires that safety be guaranteed for a set or
a domain of plausible grid states, without any explicit
accounting for their probability occurrence.
overall, switching from a reactive to a proactive management system will require many process changes. indeed, the
additional complexity cannot be handled manually so many
implicit tradeoffs will have to be made explicit. Clarifying
the type of uncertainties handled, distinguishing between
controlled and uncontrolled variations, and modeling corrective actions are some of the tasks to be achieved for a
smooth transition to the sophisticated world of predictive
management. statistics, machine learning, mathematical
optimization, and advanced simulation tools will be the
basis of the new computation process to be built. expertise
march/april 2018

and know-how are urgently needed as grid safety requires
the management of risks that occur so rarely that their statistical study is inefficient.
The set of tools developed with the framework of the apogée and iTesla projects are part of a global approach leading
rTe to update its control room by introducing an ems that is
efficient and innovative. it offers operators a series of tools to
help them control a grid that needs to be operated under more
complex scenarios as well as allowing them to concentrate on
new tasks of added value. The first modules will be put into
operation at the beginning of 2018, and the program will be
rolled out in 2018 and 2019.

The Smart Substation
The power system is operated increasingly close to its
physical limits in a context of increasing variability and
uncertainly with regard to power injections and withdrawals.
However, new flexible levers of action are made possible by
technological progress such as residential storage or higher
power storage installed in strategic locations on the transmission network, the general rollout of HVdc transmission
lines, and dynamic line rating (DLr) assessment. To integrate such levers of flexibility and easily shape new widearea complex automata to derive the optimum benefit from
new techniques and technologies, we need to shift our assets
toward more flexible and smart solutions. a smart substation
is one example of the way forward to achieve this goal.
Until recently, the refurbishment of protection and substation automation system (sas) solutions in substations was
driven by aging and economic criteria, leading to an uncoordinated deployment from a functional point of view. The recent
increasing development and maturity of intelligent electronic
devices using ieC 61850 protocols (e.g., station and process
buses) have created the design of a new generation of protection and sas solutions for the deployment of advanced area
automated functions, thus leading to a coordinated upgrade of
sass in a larger area. For obvious economic reasons, each of
these substations does not require the same level of smartness.
Thus, different solutions make sense for different situations.
For instance, the Poste intelligent project (smart substation in French) consists of two main substation refurbishments (Blocaux 225 kV/90 kV and alleaux 90 kV), located
in northern France, in which nine framing substations were
upgraded, in a windy zone where power flow limits may
occur occasionally (Figure 6).
it is worth exploring what a smart substation should
be in rTe's view. First, we consider that the traditional
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