Control Process Absolute Stability Analysis of Charge-Discharge Device With Load Converter in Constant Power Mode

Abstract

To reduce life time testing period of lithium-ion accumulator (LIA) special dynamic stress test (DST) is widely used. Lithium-ion accumulator dynamic stress test requires automatic charge-discharge devices (CDD) which provides necessary DST technological parameters with required precision. Authors developed charge-discharge devices with load converters (CDD-LC), which allow to reproduce required charge-discharge modes of highIntroduction. Reducing life time testing period of LIA can significantly accelerate and reduce the cost of design and development of lithium-ion accumulator battery (LIAB) and electrical power system (EPS) of spacecraft. To reduce life time testing period of LIA, standards are developed: GOST R IEC 62660-1-2014, GOST R IEC 61427-1-2014 2], in which the LIA life time tests are based on the dynamic stress testing (DST) method. Reduction of the terms for life time tests with DST is achieved by increasing the values of the attributes (constant current, voltage and capacity) of the charge / discharge up to the maximum values set by the manufacturer.To automate the electrical tests of LIA, including life time tests with DST, the authors developed a chargedischarge device with a load converter (CDD-LC) [3][4][5][6][7] with a pulse-width method of regulation, which due to the original topology of the LC [3][4][5][6][7], has the following advantages in comparison with the known ones [8][9][10][11][12]:-the possibility of providing the required values of the attributes of the DST LIA of a large capacity; -extended range of testing currents of LIA (0.1 A-160 A); -the possibility of LC power surplus recuperation in a direct current network of an uninterruptible power supply.CDD-LC [3][4][5][6][7] in the regime of charge / discharge LIA power stabilization can be represented as two interconnected control loops: the power stabilization loop and