# Power Systems Interview Questions

What are the assumptions made in priority list method?

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.

State the adv of forward DP approach?

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.

State the dis.adv of dynamic programming method?

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.

What are the known values in short term hydro scheduling problem?

The load, hydraulic inflows & uit availabilities are assumed known. What is meant by telemetry system? The states of the system were measured and transmitted to a control center by means of telemetry system.

What are the functions of security constraints optimal power flow?

In this function, contingency analysis is combined with an optimal power flow which seeks to make changes to the optimal dispatch of generation. As well as other adjustments, so that when a security analysis is run, no contingency result in violations.

Define the state of optimal dispatch?

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.

Define post contingency?

This is the state of the power system after a contingency has occurred. Define secure dispatch? This is state of the power system with with no contingency outages,but with correction to the operating parameters to account for security violations.

What are the priorities for operation of modern power system?

Operate the system in such a way that power is delivered reliably. Within the constraints placed on the system operation by reliability considerations, the system will be operated most economically.

What is meant by linear sensitivity factor?

Many outages become very difficult to solve if it is desired to present the results quickly. Easiest way to provide quick calculation of possible overloads is linear sensitivity factors.

What are linear sensitivity factors?

Generation shift factors line outage distribution factors.

What is the uses of line distribution factor?

It is used to apply to the testing for overloads when transmission circuits are lost.

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.