Load profile

Load profile

In electrical engineering, a load profile is a graph of the variation in the electrical load versus time. A load profile will vary according to customer type (typical examples include residential, commercial and industrial), temperature and holiday seasons.

Power generation

In the electricity generation sector, a load curve is a chart showing the amount of electricity customers use over a period of time. Generation companies use this information to plan how much power they will need to generate at any given time. A load duration curve is similar to a load curve. The information is the same but is presented in a different form. These curves are useful in the selection of generator units for supplying electricity.

Electricity distribution

In the electricity distribution business, the load profile of electricity usage is important to the efficiency and reliability of power transmission. The power transformer or battery-to-grid [ [http://www.planetark.com/dailynewsstory.cfm/newsid/44343/story.htm Planet Ark : E.ON UK Plans Giant Battery to Store Wind Power ] ] are critical aspects of power distribution and sizing and modelling of batteries or transformers depends on the load profile. The factory specification of transformers for the optimization of load losses versus no-load losses is dependent directly on the characteristics of the load profile that the transformer is expected to be subjected to [Citation | last = Eromon | first =David I. | title = The Dynamics of Transformer Purchasing in a Transformed Electric Market | journal = The International Journal of Modern Engineering | volume = 6| issue = 1 | year=2005 | url = http://www.ijme.us/issues/fall2005/articles/p33.htm] . This includes such characteristics as average load factor, utilization factor, and responsibility factor, which can all be calculated based on a given load profile.

A transformer typically has a cyclic rating allowing for the variation in the load profile. This cyclic rating allows the transformer to be overloaded at peak times so long as there is a sufficient cooling down period at the lower point in the load profile.

Retail energy markets

In retail energy markets, supplier obligations are settled on an hourly or subhourly basis. For most customers, consumption is measured on a monthly basis, based on meter reading schedules. Load profiles are used to convert the monthly consumption data into estimates of hourly or subhourly consumption in order to determine the supplier obligation. For each hour, these estimates are aggregated for all customers of an energy supplier, and the aggregate amount is used in market settlement calculations as the total demand that must be covered by the supplier.

Calculating a load profile

Load profiles can be determined by direct metering but on smaller devices such as distribution network transformers this is not routinely done. Instead a load profile can be inferred from customer billing or other data. Calculations take into account the known amount of power used and the numbers of each customer type attached. This process is called load research.

Recording load profiles

Actual demand can be collected at strategic locations to perform more detailed load analysis; this is beneficial to both distribution and end-user customers looking for peak consumption. Utility meter load profilers, data logging sub-meters and portable data loggers are designed to accomplish this task by recording readings at a set interval.

ee also

* Electricity generation
* Electric power transmission
* Electricity distribution
* Peak demand
* Transformer
* Vehicle-to-grid

External links

* [http://www.caiso.com/outlook/SystemStatus.html California Independent System Operator (Cal ISO)] Predicted system capacity and demand with approximate current demand chart for today.
* [http://www.itron.com/pages/products_category.asp?id=itr_014783.xml Itron]
* [http://www.acrsystems.com/products/applications/energy-demand-profile/ ACR Systems Inc.] Energy demand portable data logger application.


Wikimedia Foundation. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • Load Profile or Shape —   A curve on a chart showing power (kW) supplied (on the horizontal axis) plotted against time of occurrence (on the vertical axis) to illustrate the variance in a load in a specified time period …   Energy terms

  • Load Profile —   Information on a customer s usage over a period of time, sometimes shown as a graph …   Energy terms

  • visual load profile — A graph that compares work loads with available capacity against time (see diagram). Visual load profile …   Big dictionary of business and management

  • Load balancing (electrical power) — (daily peak demand reserve) refers to the use of various techniques by electrical power stations to store excess electrical power during low demand periods for release as demand rises. [cite web url=http://www.electricitystorage.org/technologies.h… …   Wikipedia

  • Load curve — A load curve is a chart showing the amount of electrical energy customers use over the course of time. Power producers use this information to plan how much electricity they will need to make available at any given time. Teletraffic engineering… …   Wikipedia

  • profile of equilibrium — 1. : the longitudinal profile of a stream whose smooth gradient is so adjusted to volume of water and amount and nature of load as to be maintained in approximate equilibrium while erosion and transportation continue : a graded profile 2. : the… …   Useful english dictionary

  • Unit Load Device — A unit load device, or ULD, is a pallet or container used to load luggage, freight, and mail on wide body aircraft and specific narrow body aircraft. It allows a large quantity of cargo to be bundled into a large unit. Since this leads to fewer… …   Wikipedia

  • Rail profile — Rail from 1896 Cross sections of flat bottomed which can rest directly …   Wikipedia

  • Depletion-load NMOS logic — Depletion load nMOS/NMOS (n channel metal oxide semiconductor) is a form of nMOS logic family which uses depletion mode n type MOSFETs as load transistors as a method to enable single voltage operation and achieve greater speed than possible with …   Wikipedia

  • Valkyrie Profile — Infobox VG title=Valkyrie Profile caption = Jewel case art from the North American version of Valkyrie Profile for the PlayStation. developer=tri Ace tri Crescendo (sound work) TOSE (PSP port) publisher=PSX: Enix PSP: Square Enix designer =… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”