Home | | **Power System Operation and Control** | Important Short Questions and Answers: Computer Control of Power Systems

Power System Operation and Control - Computer Control of Power Systems - Important Short Questions and Answers: Computer Control of Power Systems

__COMPUTER CONTROL OF POWER SYSTEMS__

**1. ****What are
the functions of control center?**

^{Ø }System monitoring contingency analysis security
constrained optimal power flow.^{}

^{ }

**2. ****What is
the function of system monitoring?**

^{Ø }System monitoring provides upto date
information about the power system.^{}

^{ }

**3. ****Define
SCADA system?**

^{Ø }It stands for supervisory control and data
acquisition system, allows a few operators to monitor the generation and high
voltage transmission systems and to take action to correct overloads.^{}

^{ }

**4. ****What are
the states of power system? Define
normal mode?**

^{Ø }Normal state alert mode contingency mode
emergency mode.^{}

^{ }

^{Ø }The system is in secure even the occurrence of
all possible outages has been simulated the system remain secure is called
normal mode.^{}

^{ }

**5. ****Define
alert mode?**

^{Ø }The occurrence of all possible outages the system
does not remain in the secure is called alert mode.^{}

^{ }

**6. ****What are
the distribution factors?**

^{Ø }Line outage distribution factor, generation
outage distribution factor.^{}

^{ }

**7. ****Define
state estimation?**

^{Ø }State estimation is the process of assigning a
value to an unknown system state variable based on measurements from that
system according to some criteria.^{}

^{ }

**8. ****Define
max. likelihood criterion?**

^{Ø }The objective is to maximize the probability
that estimate the state variable x, is the true value of the state variable
vector (i.e, to **maximize the P(x)=x**).^{}

^{ }

**9. ****Define
weighted least-squares criterion?**

^{Ø }The objective is to minimize the sum of the
squares of the weighted deviations of the estimated measurements z, from the
actual measurement.^{}

^{ }

**10.
****Define minimum variance criterion?**

^{Ø }The objective is to minimize the expected value
of the squares of the deviations of the estimated components of the state
variable vector from the corresponding components of the true state variable
vector.^{}

**11.
****Define must run constraint?**

^{Ø }Some units are given a must run status during
certain times of the year for reason of voltage support on the transmission
network.^{}

^{ }

**12.
****Define fuel constraints?**

^{Ø }A system in which some units have limited fuel
or else have constraints that require them to burn a specified amount of fuel
in a given time.^{}

^{ }

**13.
****What are the assumptions made in priority list
method?**

^{Ø }No load cost are zero unit input-output
characteristics are linear between zero output and full load there are no other
restrictions startup cost are affixed amount.^{}

^{ }

**14.
****State the adv of forward DP approach?**

^{Ø }If the start up cost of a unit is a function of
the unit is a function of the time it has been offline, then a forward dynamic
program approach is more suitable since the previous history of the unit can be
computed at each stage.^{}

^{ }

**15.
****State the dis.adv of dynamic programming
method?**

^{Ø }It has the necessity of forcing the dynamic
programming solution to search over a small number of commitment states to
reduce the number of combinations that must be tested in each period.^{}

^{ }

**16. ****What are
the known values in short term hydro scheduling problem? What is meant by
telemetry system?**

^{Ø }The load, hydraulic inflows & uit
availabilities are assumed known.^{}

^{ }

^{Ø }The states of the system were measured and
transmitted to a control center by means of telemetry system.^{}

^{ }

**17.
****What are the functions of security constraints
optimal power flow?**

^{Ø }In this function, contingency analysis is
combined with an optimal power flow which seeks to make changes to the optimal
dispatch of generation.^{}

^{ }

^{Ø }As well as other adjustments, so that when a
security analysis is run, no contingency result in violations.^{}

Ø

**18.
****Define the state of optimal dispatch?**

^{Ø }This is the state that the power system is in
prior to any contingency. It is optimal with respect to economic operation but
may not be secure.^{}

^{ }

**19.
****Define post contingency? Define secure
dispatch?**

^{Ø }This is the state of the power system after a
contingency has occurred.^{}

^{ }

^{Ø }This is state of the power system with no
contingency outages, but with correction to the operating parameters to account
for security violations.^{}

^{ }

**20.
****What are the priorities for operation of modern
power system?**

^{Ø }Operate the system in such a way that power is
delivered reliably.^{}

^{ }

^{Ø }Within the constraints placed on the system
operation by reliability considerations, the system will be operated most
economically.^{}

^{ }

**21.
****What is meant by linear sensitivity factor?**

^{Ø }Many outages become very difficult to solve if
it is desired to present the results quickly.^{}

^{ }

^{Ø }Easiest way to provide quick calculation of
possible overloads is linear sensitivity factors.^{}

^{ }

**22.
****What are linear sensitivity factors?**

^{Ø }Generation shift factors line outage
distribution factors.^{}

^{ }

**23. What is the uses of line distribution
factor?**

^{Ø} It is used to apply to the testing for overloads when transmission
circuits are lost.

**24.
****What is meant by external equvalencing?**

In order to simplify the calculations and memory storage the system
is sub divided into 3 sub systems called as external equvalencing

Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail

**Related Topics **

Copyright © 2018-2021 BrainKart.com; All Rights Reserved. (BS) Developed by Therithal info, Chennai.