Power System Flashcards
7 cards from real BEE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Power System flashcards as text
Which method is commonly used to solve the power flow (load flow) problem in large power systems?
Answer: Newton-Raphson method
The Newton-Raphson method converges quadratically and handles large, ill-conditioned systems better than Gauss-Seidel, making it the industry standard for load flow.
What is the function of a static VAR compensator (SVC) in a transmission system?
Answer: To provide dynamic reactive power support and voltage regulation
An SVC uses thyristor-controlled reactors and capacitor banks to rapidly inject or absorb reactive power, maintaining bus voltage within limits.
The equal-area criterion in power system stability analysis is used to assess:
Answer: Transient (first-swing) stability
The equal-area criterion determines whether a synchronous generator will remain stable after a sudden disturbance by comparing accelerating and decelerating energy areas on a P-δ curve.
Which parameter of a transmission line is primarily responsible for the charging current?
Answer: Shunt capacitance
The shunt (line-to-ground) capacitance of a transmission line causes capacitive charging current to flow even when no load is connected.
A generator's synchronizing coefficient Ps is positive. What does this indicate?
Answer: The generator tends to return to synchronism after a small disturbance
A positive synchronizing coefficient (dP/dδ > 0) means the machine develops a restoring torque when displaced from equilibrium, ensuring steady-state stability.
In a distribution system, what is the advantage of a ring (loop) network over a radial network?
Answer: Higher supply continuity and improved reliability
A ring network supplies each load from two directions, so a single fault or maintenance outage does not interrupt supply, improving reliability.
What is the primary purpose of the excitation system of a synchronous generator?
Answer: To regulate the DC field current and thereby control terminal voltage and reactive power
The excitation system adjusts the rotor field current, controlling the generator's terminal voltage and its contribution to reactive power in the system.