Estimation of the Heating of Crimped Connections Based on Experimental Tests

In this work, some analytical formulas based on experimental tests are presented that can be used to estimate the heating of the crimped connections used in construction of electrical machines, saving the experimenter from additional, long and expensive tests. The formulas are based on the energy balance equation and combine practical results obtained from previous steady-state heating cycles for a set of 6 crimped connections of the same type, at currents close to the nominal value. There are standards that allow the esti-mation of the heating of the elements in the circuit at small variations of the test current. Thus, based on the heating obtained at one value of the current, the heating at another, slightly different value can be estimated, without the need for the actual experiment. For a more accurate estimation, the variation with temperature of the electrical resistances of the 6 connectors must be taken into account, which allows the extension of the estimation range. In this case, if there are two heating cycles performed at two different values of the current, estimations can also be made at other values, much different from the two. A global temperature coefficient of resistance can be deduced that can simplify the formulas while keeping the precision, serving to estimate the average heating of the connectors. The formulas have been validated for several types of crimped connections used in the construction of electrical machines.