Line compensation improve power system operation by

Question

Examoogle · Accepted Answer

All of above

Explanation: Line compensation refers to the use of reactive power compensators (like Shunt Capacitors, Reactors, or SVCs) to control the voltage profile along a transmission line. By managing reactive power flow, it ensures the bus voltage remains within regulatory limits, minimizes transmission losses, and prevents instability during heavy loads.

Working Principle: The principle relies on managing the reactive power balance, $Q$, in the line. By injecting reactive power ($Q_{in} > 0$ via capacitors) or absorbing it ($Q_{in}

Key Formulas: $V_{drop} \approx I(R\cos\phi + X\sin\phi)$ — Voltage drop across the line; $P_{max} = \frac{V_S V_R}{X} \sin\delta$ — Power transfer capability limit

Key Points: Shunt compensation is primarily used for voltage regulation.; Series compensation is used to decrease the line impedance ($X$) to increase power transfer limits.; Excessive reactive power flow increases copper losses in transmission lines.; Compensation stabilizes the system against voltage instability and collapse.

Advantages: Improved voltage profile throughout the transmission line; Reduction in $I^2R$ power transmission losses; Increased transient and steady-state stability; Improved power factor of the system

Disadvantages: High capital cost of installing FACTS devices or compensators; Potential for harmonic distortion if not filtered correctly; Complexity in control and protection schemes

Applications: Long-distance EHV and UHV transmission lines; Industrial feeders with heavy inductive loads; Grid stabilization in renewable energy integration

Additional Info: Voltage regulation is maintained by adjusting the shunt susceptance or series reactance.. Option A is correct but incomplete as compensation also impacts stability and losses.. Option B relates to the reduction of $I^2R$ losses, which is a outcome of better voltage and current profile management.. Option C refers to the Power-Angle curve where reducing effective $X$ increases the stability limit ($P_{max}$).

Answer: D is correct — Line compensation maintains voltage stability, reduces transmission losses, and enhances the overall stability margin by managing reactive power flow.

Exam Tip: Always remember that while shunt compensation primarily improves voltage, series compensation (like series capacitors) is specifically used to increase the power transfer capability ($P_{max}$) by reducing the effective line reactance.

Related Questions

Discussion (0)