Power Plant Control Modes Quiz

Questions and Answers

What is the formula for area requirement for system A?

ARA = K′A ⋅ ∆PT - ∆f

ARA = K′A ⋅ ∆PT + ∆f

ARA = K′A ⋅ ∆f + ∆PT (correct)

ARA = K′A ⋅ ∆f - ∆PT

What is the condition for no Load Frequency Control (LFC) for both systems A and B?

∆C A ≠ 0 and ∆C B = 0

∆C A ≠ 0 and ∆C B ≠ 0

∆C A = 0 and ∆C B = 0 (correct)

∆C A = 0 and ∆C B ≠ 0

In case (II), what is the value of ∆f?

∆f = K A ⋅ ∆PT

∆f = K B ⋅ ∆PT

∆f = 0 (correct)

∆f = K A ⋅ ∆PA

What is the expression for ∆PT in case (II)?

∆PT = -∆PB Signup and view all the answers

In case (III), what is the condition for the power imbalance?

∆PT = 0 Signup and view all the answers

What is the expression for ∆C A in case (III)?

∆C A = ∆PB - ∆PA Signup and view all the answers

What is the effect of ∆PB on the frequency deviation in case (III)?

It causes a larger frequency deviation Signup and view all the answers

What is the primary purpose of Governor Free Operation (GF) mode?

To respond quickly to frequency deviation Signup and view all the answers

What is the characteristic of Load Frequency Control (LFC) in a power system?

It adjusts the frequency to match the load Signup and view all the answers

In the context of power plant control, what is EDC?

Economic Dispatching Control, which controls according to the prepared daily dispatching plan to minimize fuel costs Signup and view all the answers

What is the function of the turbine governor in a power plant?

To adjust the speed of the turbine Signup and view all the answers

What type of control mode is used to adjust governor settings by the control center of a power system?

Load Frequency Control (LFC) Signup and view all the answers

What is the purpose of the droop characteristics in Governor-Free Control?

To reduce the mechanical input when the speed is too fast Signup and view all the answers

What is the condition for ΔCA to compensate only ΔPA?

K' = 0 Signup and view all the answers

What is the benefit of Economic Dispatching Control (EDC) mode?

Minimization of fuel costs Signup and view all the answers

What is the expression for Δf when there is no LFC for B?

Δf = KA ⋅ ∆PA / (KA + KB) Signup and view all the answers

Which control mode is used for local control of the plant to respond quickly to frequency deviation?

Governor Free Operation (GF) Signup and view all the answers

What is the relationship between ΔPT and ΔPB when ΔCB = 0?

ΔPT = -ΔPB Signup and view all the answers

What is the function of the control center in Economic Dispatching Control (EDC) mode?

To control governor settings and daily start and stop Signup and view all the answers

What is the condition for a system to be under FFC?

K' = ∞ Signup and view all the answers

What type of component is represented by curve C in the total demand curve?

Short cycle component Signup and view all the answers

What is the purpose of ΔCA in LFC?

To compensate only ΔPA Signup and view all the answers

What is the primary function of the controller in a power plant?

To monitor and respond to changes in frequency and load Signup and view all the answers

What happens when the control speed of TBC is faster than that of FFC?

Insufficient control occurs Signup and view all the answers

What is the expression for ΔCB when there is FFC for B?

ΔCB = -ΔPB Signup and view all the answers

What is the condition for ARA = 0?

ΔPA + ΔCA - ΔPT = 0 Signup and view all the answers

What is the main objective of the EDC process?

To allocate generation output levels to minimize operation costs Signup and view all the answers

What is a constraint in the EDC process?

Transmission line capacities Signup and view all the answers

What is a capability of Nuclear Power Plants (NPPs)?

Both load following and frequency control Signup and view all the answers

What is a consequence of variable output operation of NPPs?

Increased maintenance costs Signup and view all the answers

Which country operates NPPs in the load-following mode with large daily power variations?

Some European countries Signup and view all the answers

Which type of reactor uses Boric acid for control?

PWR Signup and view all the answers

What is the share of NPPs in France's power generation?

About 75% Signup and view all the answers

In which country are NPPs operated in the constant output mode?

Japan Signup and view all the answers

What is the requirement to determine all the variables in a system with LFC representations of 3 systems?

Fix the power flow of one of the three tielines at a specific value Signup and view all the answers

What is the primary purpose of Load Frequency Control (LFC)?

To control the frequency of the power system Signup and view all the answers

What type of power plants are generally used as frequency control facilities?

Thermal power plants and large hydro power plants Signup and view all the answers

What is the approximate capacity required for Load Frequency Control (LFC) in a power system?

5% of the total system capacity Signup and view all the answers

What is the purpose of Economic Dispatching Control (EDC)?

To optimize the dispatch of power generation units Signup and view all the answers

What type of connection is employed in real systems in Japan to fix the power flow?

DC connection Signup and view all the answers

What is the result of considering LFC representations of 3 systems?

We have 1 degree of freedom in the total system Signup and view all the answers

What is the equation used in Load Frequency Control (LFC)?

∆ci(t) = −ki ∫ (K ′ ⋅ ∆f + ∆PT)dt + EDCi Signup and view all the answers

What is the frequency of the power system in the Kyusyu region?

60Hz Signup and view all the answers

What is the purpose of the Control Center in the LFC system?

To monitor and control the LFC and EDC systems Signup and view all the answers

Study Notes

Power and Frequency Control

Power plants have three control modes: Governor Free Operation (GF), Load Frequency Control (LFC), and Economic Dispatching Control (EDC)
GF: local control of plant to respond quickly to frequency deviation, control of valves by a turbine governor
LFC: governor settings adjustment by the control center of a power system
EDC: control according to the prepared daily dispatching plan to minimize fuel costs, control of governor settings and daily start and stop from the control center of a power system

Governor-Free Control

Droop characteristics of GF: if the speed is too fast, mechanical input is to be reduced
No LFC: ΔC = 0
ARi: area requirement for system i, Ki: estimated power-frequency coefficient of system i

Load Frequency Control (LFC)

Behaviors of the inter-connected power systems:
- (I) No LFC for both A and B (only GF and self regulation of load)
- (II) FFC for A and no LFC for B (including case of very slow LFC for B)
- (III) FTC for A and no LFC for B (including case of very slow LFC for B)
- (IV) TBC for A and no LFC for B (including very slow LFC for B)
- (V) TBC for A and FFC for B
The necessary capacity for LFC is around 5% of the total system capacity
Thermal power plants and large hydro power plants are generally used as frequency control facilities due to their high manoeuvring capability

Economic Dispatching Control (EDC)

EDC is defined as the process of allocating generation output levels to the generating units in the power system, so that the system load can be supplied most economically
Objective function: total operation cost of the system over the time horizon
Constraints:
- Electricity demand and supply balances
- Transmission line capacities
- Electricity storage capacities of pumping-up hydro power stations
- Load following capabilities
- Minimum and maximum output levels of the plants

Comments on Nuclear Power Plants

Nuclear power plants (NPPs) have the capability of load following and frequency control
NPPs can operate in the load-following mode with large daily power variations of about 50% of rated power
Some NPPs also participate in the frequency control of the total power system
In Japan, the NPPs are operated in the constant output mode

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Description

This quiz covers the three types of plant control modes, including Governor Free Operation (GF), in a power plant. It's a crucial aspect of power and frequency control.