IEEE 1115-2000 pdf free.IEEE Recommended Practice for Sizing Nickel-Cadmium Batteries for Stationary Applications.
IEEE 1115 The lists of typical loads appearing in 4.2.1 and 4.2.2 are not a full catalog of the dc loads at any particularinstallation. Loads applied to the battery are normally typed as constant power, constant resistance,orconstant current.However, for sizing purposes, loads are treated as constant power or constant current. Thedesigner should review each system carefully to be sure all possible loads and their variations are included(see Annex B).
A duty cycle diagram showing total load at any time during the cycle is an aid in the analysis of the dutycycle. To prepare such a diagram , all loads, expressed as either power or current expected during the cycle,are tabulated along with their anticipated inception and shutdown times. The total time span of the dutycycle is determined by the requirements of the installation.
Loads that have inception and shutdown times that are known are plotted on the duty cycle diagram as theywould occur. If the inception time is known, but the shutdown time is indefinite, it should be assumed thatthe load will continue through the remainder of the duty cycle.
The battery manufacturers should be contacted for detailed cell design and performance characteristics toallow proper selection and sizing of a battery for a specific application.
Several basic factors govern the size (number of cells and rated capacity) of the battery.Included are themaximum system voltage, the minimum system voltage, the duty cycle,correction factors,and designmargin.Since a battery string is usually composed of a number of identical cells connected in series, thevoltage of the battery is the voltage of a cell multiplied by the number of cells in series. The ampere-hourcapacity of a battery string is the same as the ampere-hour capacity of a single cell.
lf cells of sufficiently large capacity are not available, then two or more strings, of equal number of series-connected cells, may be connected in parallel to obtain the necessary capacity.The ampere hour capacity ofsuch a battery is the sum of the ampere-hour capacities of the strings. The manufacturer should be consultedfor any limitation on paralleling.IEEE 1115 pdf download.