Test #2. Control system of Microgrid

Islanded microgrid operation is characterized by

• Frequency and voltage are controlled by local generation under direction of a controller

• Frequency and voltage are controlled by main grid via a microgrid controller

• Frequency and voltage are not controlled

• All of the above

Which of the following statement in isolated mode is correct?

• All the DGs operate in PQ mode

• All the DGs operate in VF mode

• Some DGs in PQ mode and Some DGs in VF mode

• None of the above

AC microgrid generator which can regulate voltage and frequency in the islanded operation mode

• PV connected inverter.

• Diesel Generator.

• Grid.

• PMSG wind

The Primary control of microgrid is

• the level in the control hierarchy that consists of inner loops (current/voltage regulation), droop control (preliminary power sharing) and used for local measurements (voltage stability provision, frequency stability preserving, plug and play capability of distributed generators)

• the level in the control hierarchy that is responsible for the reliable, secure and economical operation of microgrid in either grid-connected or islanded mode (compensating the voltage and frequency deviation caused by previous level)

• the level in the control hierarchy that considers the economical concerns in the optimal operation of the microgrid, and manages the power flow between microgrid and main grid (optimal operating in both grid-connected or islanded operation mode, power flow control in grid-connected mode, economic dispatching)

• None of the above

The Secondary control of microgrid is

• the level in the control hierarchy that consists of inner loops (current/voltage regulation), droop control (preliminary power sharing) and used for local measurements (voltage stability provision, frequency stability preserving, plug and play capability of distributed generators)

• the level in the control hierarchy that considers the economical concerns in the optimal operation of the microgrid, and manages the power flow between microgrid and main grid (optimal operating in both grid-connected or islanded operation mode, power flow control in grid-connected mode, economic dispatching)

• the level in the control hierarchy that is responsible for the reliable, secure and economical operation of microgrid in either grid-connected or islanded mode (compensating the voltage and frequency deviation caused by previous level)

• None of the above

The Tertiary control of microgrid is

• the level in the control hierarchy that consists of inner loops (current/voltage regulation), droop control (preliminary power sharing) and used for local measurements (voltage stability provision, frequency stability preserving, plug and play capability of distributed generators)

• the level in the control hierarchy that considers the economical concerns in the optimal operation of the microgrid, and manages the power flow between microgrid and main grid (optimal operating in both grid-connected or islanded operation mode, power flow control in grid-connected mode, economic dispatching)

• the level in the control hierarchy that is responsible for the reliable, secure and economical operation of microgrid in either grid-connected or islanded mode (compensating the voltage and frequency deviation caused by previous level)

• None of the above

The assessment of optimal place and size of distributed generation is based on

• Minimization of active power losses, peak demand saving, improved reliability and security.

• Minimization of active power losses, improved voltage stability.

• Improved voltage stability, peak demand saving, minimization installation cost.

• All of the above.