Investigation of energy processes in circuits of oscillatory charge of supercapacitors

Investigation of the Energy Characteristics of a Circuit under the Charge of a Supercapacitor and an Equivalent Linear Capacitor

“…Taking into account expression (3) for branching the modes of operation of the SC, in accordance with works [2,3,[8][9][10][11][12][13][14][15][16][17][18][19][20], it is necessary to use branched substitution schemes. In order to take into account the distributed electrical parameters of supercapacitors, their branched substitution schemes with different numbers of parallel branches containing concentrated linear and nonlinear elements C, R and L were proposed.…”

“…This curve can be approximated with sufficient accuracy by the linear function C(U) when the SC is used at a voltage of 0.5U n to U n (where U n is the nominal voltage of the SC). A number of studies [3,[8][9][10][11][12][13][14][15][16][17][18][19][20] have confirmed that the supercapacitor stores up to 75% of energy in this voltage range.…”

“…The dependence of the capacitance of supercapacitors on the voltage at its terminals was taken into account during the research. In studies conducted in [2,3,[13][14][15][16][17][18][19][20][21][22][23] it was noted that the physics of the SC involves the presence of part of the capacitance, which depends on the applied voltage to its terminals. Experimental measurements of charge from a DC voltage source were performed for SCs with a capacitance of 470, 1500 and 2600 F [18,20,21].…”

“…Exceptions are, for example, devices that use ferroelectrics, i.e., substances in which the dielectric constant is a function of U. For supercapacitors, the magnitude of the capacitance C is a function of the voltage U [2,3,[8][9][10][11][12][13][14][15][16][17][18][19][20]. Expression (2) is valid for both LC and SC, because it establishes the relationship between the charge accumulated on each of the plates Q and the voltage between them U.…”

“…Therefore, in the combined power sources of electric vehicles, supercapacitors provide pulse modes of high power consumption in the load, and the battery provides long-term operation of the electromechanical system in steady state [3,5,[8][9][10][11][12]. A detailed review of the results of the analysis of the energy characteristics of supercapacitors [2,[8][9][10][11][12][13][14][15][16][17][18][19][20][21] showed that research has been conducted without taking into account the loss of electricity in the circuits of charge, recharging and internal redistribution of supercapacitor charges. There was also no analysis of electricity losses in the charge circuits of supercapacitors from the battery under non-zero initial voltage conditions.…”