Abstract
Original language  English 

Qualification  Doctor Degree 
Awarding Institution 

Supervisors/Advisors 

Award date  29 Nov 1996 
Place of Publication  Espoo 
Publisher  
Print ISBNs  9513849473 
Electronic ISBNs  9513852008 
Publication status  Published  1996 
MoE publication type  G4 Doctoral dissertation (monograph) 
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Keywords
 electric power generation
 electric power distribution
 electric loads
 load research
 load estimation
 electricity
 distribution systems
 customers
 measurement
 models
 variations
 analyzing
Cite this
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Load research and load estimation in electricity distribution : Dissertation. / Seppälä, Anssi.
Espoo : VTT Technical Research Centre of Finland, 1996. 137 p.Research output: Thesis › Dissertation › Monograph
TY  THES
T1  Load research and load estimation in electricity distribution
T2  Dissertation
AU  Seppälä, Anssi
N1  Project code: N6SU00026
PY  1996
Y1  1996
N2  The topics introduced in this thesis are: the Finnish load research project, a simple form customer class load model, analysis of the origins of customers load distribution, a method for the estimation of the confidence interval of customer loads and Distribution Load Estimation (DLE) which utilises both the load models and measurements from distribution networks. These developments bring new knowledge and understanding of electricity customer loads, their statistical behaviour and new simple methods of how the loads should be estimated in electric utility applications. The economic benefit is to decrease investment costs by reducing the planning margin when the loads are more reliably estimated in electrc utilities. As the Finnish electricity production, transmission and distribution is moving towards the deregulated electricity markets, this study also contributes to the development for this new situation. The Finnish load research project started in 1983. The project was initially coordinated by the Association of Finnish Electric Utilities and 40 utilities joined the project. Now there are over 1000 customer hourly load recordings in a database. A simple form customer class load model is introduced. The model is designed to be practical for most utility applications and has been used by the Finnish utilities for several years. There is now available models for 46 different customer classes. The only variable of the model is the customers annual energy consumption. The model gives the customers average hourly load and standard deviation for a selected month, day and hour. The statistical distribution of customer loads is studied and a model for customer electric load variation is developed. The model results in a lognormal distribution as an extreme case. The model is easy to simulate and produces distributions similar to those observed in load research data. Analysis of the load variation model is an introduction to the further analysis of methods for confidence interval estimation. Using the `simple form load model, a method for estimating confidence intervals (confidence limits) of customer hourly load is developed. The two methods selected for final analysis are based on normal and lognormal distribution estimated in a simplified manner. The simplified lognormal estimation method is a new method presented in this thesis. The estimation of several cumulated customer class loads is also analysed. Customer class load estimation which combines the information from load models and distribution network load measurements is developed. This method, called Distribution Load Estimation (DLE), utilises information already available in the utilitys databases and is thus easy to apply. The resulting load data is more reliable than the load models alone. One important result of DLE is the estimate of the customer class share to the distribution systems total load.
AB  The topics introduced in this thesis are: the Finnish load research project, a simple form customer class load model, analysis of the origins of customers load distribution, a method for the estimation of the confidence interval of customer loads and Distribution Load Estimation (DLE) which utilises both the load models and measurements from distribution networks. These developments bring new knowledge and understanding of electricity customer loads, their statistical behaviour and new simple methods of how the loads should be estimated in electric utility applications. The economic benefit is to decrease investment costs by reducing the planning margin when the loads are more reliably estimated in electrc utilities. As the Finnish electricity production, transmission and distribution is moving towards the deregulated electricity markets, this study also contributes to the development for this new situation. The Finnish load research project started in 1983. The project was initially coordinated by the Association of Finnish Electric Utilities and 40 utilities joined the project. Now there are over 1000 customer hourly load recordings in a database. A simple form customer class load model is introduced. The model is designed to be practical for most utility applications and has been used by the Finnish utilities for several years. There is now available models for 46 different customer classes. The only variable of the model is the customers annual energy consumption. The model gives the customers average hourly load and standard deviation for a selected month, day and hour. The statistical distribution of customer loads is studied and a model for customer electric load variation is developed. The model results in a lognormal distribution as an extreme case. The model is easy to simulate and produces distributions similar to those observed in load research data. Analysis of the load variation model is an introduction to the further analysis of methods for confidence interval estimation. Using the `simple form load model, a method for estimating confidence intervals (confidence limits) of customer hourly load is developed. The two methods selected for final analysis are based on normal and lognormal distribution estimated in a simplified manner. The simplified lognormal estimation method is a new method presented in this thesis. The estimation of several cumulated customer class loads is also analysed. Customer class load estimation which combines the information from load models and distribution network load measurements is developed. This method, called Distribution Load Estimation (DLE), utilises information already available in the utilitys databases and is thus easy to apply. The resulting load data is more reliable than the load models alone. One important result of DLE is the estimate of the customer class share to the distribution systems total load.
KW  electric power generation
KW  electric power distribution
KW  electric loads
KW  load research
KW  load estimation
KW  electricity
KW  distribution systems
KW  customers
KW  measurement
KW  models
KW  variations
KW  analyzing
M3  Dissertation
SN  9513849473
T3  VTT Publications
PB  VTT Technical Research Centre of Finland
CY  Espoo
ER 