# FACTS Questions and Answers – Switching Converter Type Series Compensators

This set of FACTS Multiple Choice Questions & Answers (MCQs) focuses on “Switching Converter Type Series Compensators”.

1. An ideal switch has conduction losses.
a) True
b) False

Explanation: An ideal switch has NO conduction losses. Conduction losses come into play in ON condition, i.e. when the switch conducts. An ideal switch in ON condition, does not exhibit any voltage drop across it and so has no losses during conducting or passing current through it.

2. An ideal switch has blocking losses.
a) True
b) False

Explanation: An ideal switch has NO blocking losses. Blocking losses come into play in OFF condition, i.e. when the switch does not conduct. An ideal switch in OFF condition, does not exhibit any leakage current across it and so has no losses during blocking current through it.

3. An ideal switch has switching losses.
a) True
b) False

Explanation: An ideal switch has NO switching losses. Switching losses come into play when the switch changes its position from OFF condition to ON condition and vice versa. An ideal switch in OFF condition does not require any time to change to ON condition and vice versa. Due to their instantaneous switching activity, an ideal switch has no losses during switching ON/OFF.

4. The V/I characteristics of an ideal switch lie ________ in V-I plane.
a) along the axes
b) away from the axes
c) at the origin
d) near to the axes

Explanation: The V/I characteristics of an ideal switch lie along the axes in V-I plane. This is because there is NO leakage current across it in OFF condition and NO conduction voltage drop across it in ON condition. Practical switches behave differently from ideal switches.

5. Practical Switches have instantaneous switching characteristics.
a) True
b) False

Explanation: Practical Switches DO NOT have instantaneous switching characteristics. Unlike ideal ones, they take finite time to change their positions from OFF condition to ON condition and vice versa. This finite switching time leads to limited operating frequency.

6. Practical switches are lossless.
a) True
b) False

Explanation: Unlike ideal switches, practical switches are NOT lossless. They have blocking loss, conduction loss and switching loss. The V/I characteristics of a practical switch lie close to the axes in V-I plane, within certain defined limits.

7. Practical switches block infinite voltage during OFF condition.
a) True
b) False

Explanation: Practical switches CANNOT block infinite voltage during OFF condition due to their inherent limitations. It is the Ideal switches that block infinite voltage during OFF condition. Hence in the V-I plane the voltage plot of an ideal switch in OFF condition extents along the X-axis from -∞ to +∞.

8. Practical switches pass infinite current during ON condition.
a) True
b) False

Explanation: Practical switches CANNOT pass infinite current during ON condition due to their inherent limitations. It is the Ideal switches that can pass infinite current during ON condition. Hence in the V-I plane the current plot of an ideal switch in ON condition extents along the Y-axis from -∞ to +∞.

9. Practical switches have limited safe operating area in V-I plane for transient operation.
a) True
b) False

Explanation: Practical switches have limited safe operating area in V-I plane for transient operation. This is because a practical switch can support finite voltage and finite current through it. Also it has limited switching frequency and associated losses.

10. Ideal switches have limited safe operating area in V-I plane for transient operation.
a) True
b) False

Explanation: Ideal switches DO NOT have limited safe operating area in V-I plane for transient operation. This is because an Ideal switch can support infinite voltage and infinite current through it. Also it has instantaneous switching characteristic and has NO associated losses.

Sanfoundry Global Education & Learning Series – Flexible AC Transmission System (FACTS).

To practice all areas of Flexible AC Transmission System (FACTS), here is complete set of 1000+ Multiple Choice Questions and Answers.

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