Load Forecasting

Question 1

What does ampacity refer to in load centers?

Answer 1

Maximum continuous current a load center is designed to handle.

Question 2

What is the common ampacity service for older residences?

Answer 2

100A service.

Question 3

What is the typical ampacity service for newer residences?

Answer 3

200A service.

Question 4

What is a load center also known as?

Answer 4

Breaker panel.

Question 5

What materials are commonly used for the construction of load centers?

Answer 5

• Cold rolled steel (indoor)
• Galvanized steel (outdoor)

Question 6

What does LDC stand for?

Answer 6

Load Duration Curve.

Question 7

What is the purpose of an LDC in power generation?

Answer 7

Illustrates the relationship between generating capacity requirements and capacity utilization.

Question 8

What is the definition of a load duration curve?

Answer 8

A curve between the load and time with load plotted in order of decreasing magnitude.

Question 9

What is the main unit of an artificial neural network (ANN)?

Answer 9

Neuron.

Question 10

What are the three main features that determine an ANN?

Answer 10

• Structure of the network
• Weights defining learning rules
• Activation function between input and output neurons

Question 11

What are the two types of load centers?

Answer 11

• Main breaker
• Main lug only

Question 12

What is the function of a main breaker load center?

Answer 12

Disconnects power from the load center and provides overcurrent protection.

Question 13

What is a main lug only load center?

Answer 13

A load center without a main circuit breaker; incoming supply cables connect directly to the main lugs.

Question 14

What is the importance of grounding in load centers?

Answer 14

Grounding is critical to electrical safety and is covered by NEC Article 250.

Question 15

How is average demand calculated?

Answer 15

Average Demand = Total Load (MW) / Total Time (hrs)

Question 16

What is the general lighting load calculated at per square foot according to NEC?

Answer 16

3VA per square foot.

Question 17

What is the purpose of the demand factor in sizing electric services?

Answer 17

To account for the fact that all residential loads are not used at the same time.

Question 18

What is the total load calculated in the example provided?

Answer 18

33,826VA.

Question 19

What is the required load center rating for a total load of 33,826VA?

Answer 19

140.94A.

Question 20

What safety factor is added to the load center requirements?

Answer 20

20%.

Question 21

What is the final recommended load center size for the example?

Answer 21

200A.

Question 22

What does the time series technique analyze?

Answer 22

Load evolution over time to predict future loads.

Question 23

What is an advantage of the time series technique?

Answer 23

Ability to adopt seasonal effects.

Question 24

What does fuzzy logic consider as inputs?

Answer 24

Qualitative ranges instead of binary values.

Question 25

What is a key advantage of fuzzy logic systems?

Answer 25

Powerful in forecasting electric load.

Question 26

What does short-term load forecasting (STF) utilize?

Answer 26

Historical load and weather data.

Question 27

What is the typical forecast duration for short-term load forecasting?

Answer 27

Next 24 hours.

Question 28

What is a significant advantage of Fuzzy Logic in load forecasting?

Answer 28

No much existence of mathematical model to design map between inputs and outputs.

Question 29

What is the role of Fuzzy Logic systems in electric load forecasting?

Answer 29

Powerful in the forecast of electric load.

Question 30

What does 'defuzzification' refer to in the context of Fuzzy Logic?

Answer 30

Room for 'defuzzification' for precise outputs.

Question 31

How quick and accurate are Fuzzy Logic systems in execution?

Answer 31

Quick and accurate in execution.

Question 32

What data is used for Short Term Load Forecasting?

Answer 32

Historical load and weather data.

Question 33

What are the applications of Short Term Load Forecasting?

Answer 33

Resource balancing and demand response and smart grid applications.

Question 34

What is the timeframe for Short Term Forecast (STF)?

Answer 34

Next 24 hours or week.

Question 35

What type of data is sourced from SCADA for load forecasting?

Answer 35

Real Time Load Data from SCADA through energy meters.

Question 36

What are the results of Long Term Load Forecasting used for?

Answer 36

Generation, transmission planning, capital investment.

Question 37

What is the timeframe for Long Term Forecast (LTF)?

Answer 37

Up to 20 years.

Question 38

What are the three main categories of Load Forecasting (LF) based on time-horizon?

Answer 38

* Long-Term Forecasting (LTF): 1-20 years * Medium-Term Forecasting (MTF): 1 week-1 year * Short-Term Forecasting (STF): 1 hour-1 week.

Question 39

What does Load Forecasting (LF) refer to?

Answer 39

Projected systematic process of defining future loads in sufficient quantitative detail.

Question 40

What is one essential role of Load Forecasting?

Answer 40

Scheduling of electricity and management of power system.

Question 41

What are some values of advanced Load Forecasting?

Answer 41

* Capacity planning * Managing the generation & transmission capital investment * Optimal supply and scheduling * Peak reduction market evaluation * Efficient power procurement * Selling of excess energy * Fuel ordering planning.

Question 42

What factors affect Load Forecasting?

Answer 42

* Historical Data * Population growth * Load density * Alternative Energy sources * Geographical Factors * Community Development Plans * Industrial Plans * City plans * Land use.

Question 43

What is an Expert System in load forecasting?

Answer 43

Used computer programming to explain and expand knowledge base information.

Question 44

What coding method does an Expert System use?

Answer 44

Translates information in coding form using facts and IF THEN conditions.

Question 45

What is one advantage of using an Expert System?

Answer 45

Convenience in the knowledge of expert system.

Question 46

What is a reason for Load Forecasting?

Answer 46

Ensures availability of supply.

Question 47

What is one uncertainty associated with Load Forecasting?

Answer 47

Highly capital intensive.

Question 48

What are common statistical techniques or algorithms used in Load Forecasting?

Answer 48

* Regression * Neural networks * Fuzzy logic * Expert systems.

Question 49

What are the two main methods used for medium-term and long-term forecasting?

Answer 49

* End-use approaches * Econometric approaches.

Question 50

What are the classical methods of electric load forecasting?

Answer 50

* Repeated re-weighted least squares technologies * Exponential smoothing * Linear and multiple regressions.

Question 51

What are some examples of modern techniques of load forecasting?

Answer 51

* Support vector machines * Wavelet network * Neural Networks (NNS) * Genetic Algorithms (GAS) * Fuzzy Logic (FL).

Question 52

What are the two categories of forecasting models based on mathematical analysis?

Answer 52

* Quantitative * Qualitative methods.

Question 53

What do quantitative techniques depend on for future forecasting?

Answer 53

Past data.

Question 54

What do qualitative techniques rely on?

Answer 54

Judgment and opinion of experts and consumers.