In this note, we have listed some related terms of the Economics of Power Generation and Interconnected Power Station chapter for electrical engineering students. Welcome to Poly Notes Hub, a leading destination for diploma and degree engineering notes for polytechnic and b-tech students all of over the world.
Author Name: Arun Paul.
Economics of Power Generation and Interconnected Power Station – Related Terms
What is Connected Load?
Connected Load is the total sum of the rated capacities of all the electrical appliances or equipment connected to the power supply system.
Key Points:
- Represents the maximum possible load connected to the system.
- Measured in kilowatts (kW) or megawatts (MW).
- All connected devices may not operate simultaneously.
- Used to estimate the total electrical demand in a system.
Example: If a house has a 100 W fan, 200 W TV, and 300 W heater → Connected Load = 600 W.
What is Firm Power?
Firm Power refers to the guaranteed amount of electrical power that a generating station can supply continuously and reliably under normal operating conditions.
Key Points:
- Known as assured or dependable power.
- Supplied to essential industries and consumers.
- Available even during peak demand or power fluctuations.
Example: The firm power supplied to an industrial plant ensures uninterrupted production.
What is Cold Reserve?
Cold Reserve is the part of generating capacity that is not in operation but can be brought into service after some time, usually a few hours.
Key Points:
- Requires start-up time to reach operational condition.
- Used during emergency situations or maintenance.
- Commonly found in thermal and hydroelectric power stations.
Example: A thermal unit kept shut down but ready for future use.
What is Hot Reserve?
Hot Reserve is the generating capacity that remains running and synchronized with the power system but is not carrying any load.
Key Points:
- Can be quickly loaded when demand increases.
- Ensures immediate backup for sudden power failures.
- Considered part of the operating reserve.
Example: A turbine kept running at no-load condition.
What is Operating Reserve?
Operating Reserve is the extra generating capacity available to meet unexpected increases in load demand or sudden equipment failure.
Key Points:
- Must be ready for instant or quick use.
- Ensures system reliability and stability.
- Includes spinning, hot, and cold reserves.
Example: Ensures stability and reliability of the power system.
What is Spinning Reserve?
Definition:
Spinning Reserve is the portion of total generating capacity that is connected, running, and synchronized with the system but not fully loaded.
Key Points:
- Can be brought into operation immediately.
- Provides fast response to sudden load changes.
- Helps maintain system frequency and voltage stability.
Example: A generator operating at 80% load has 20% spinning reserve.
What is Average Demand?
Average Demand is the average load on a power station during a specific time period, such as a day, month, or year.
Formula:
Key Points:
- Indicates the overall utilization of the plant.
- Used to calculate load factor.
- Measured in kW or MW.
Example: If a station generates 2400 kWh in 24 hours → Average demand = 100 kW.
What is Maximum Demand?
Maximum Demand is the highest load that occurs on a power station during a given period of time.
Key Points:
- Determines the plant capacity and tariff rates.
- Measured using a maximum demand indicator.
- Expressed in kW or MW.
Example: If the load reaches 150 kW once in a day, that is the maximum demand.