Methodology for Selecting the Ionistor Balancing Current in Modules and Storage Devices of JSC “Elecond” for Stabilized Current Charging

Abstract

Technical, technological and methodological solutions are presented within the framework of the methodology to ensure balancing and overvoltage protection of ionistors in resistive balancing modules with a current much less than the stabilized charging current. To protect against overvoltage, the use of ionistors in the module with undercharging and up to the rated voltage is justified. The relationship between the ionistor undercharge voltage and the allowable final level of their capacitance deviation with respect to the average modulo capacitance eliminating ionistor overvoltage, is shown. A method for selecting the ionistor undercharge voltage modulo value and the ionistor maximum initial capacity spread modulo value, based on a statistical assessment of the of ionistor reliability test results, is proposed. The optimal undercharge voltage of 0.2 V and the maximum initial technological deviation of the ionistor capacitance modulo value of ± 2.5%, providing a final spread of their capacitance relative to the average modulo no more than ± (6.5 ...7.0) % and, as a result, protection against overvoltage at any balancing currents during the entire operating time,were determined. In this case, it is proposed to calculate the balancing current based on the required time of ionistor voltage reduction only to ensure equality of their operating time. A functional dependence that provides the calculation of the current and the balancing coefficient in case of exceeding 7.0 % of the ionistor capacitance deviation barrier modulo value during operationhas been established. The technical, technological and methodological solutions presented within the framework of the methodology to ensure the choice of balancing current, were tested during the development of ionistor industrial modules MIP of “Elecond” JSC and showed satisfactory resistance and strength of parameters to the effects of climatic and mechanical factors, as well as during tests for durability and reliability. The methodology of current and balancing coefficient selection is extended to the development of high-voltage ionistor units as part of high-voltage ionistor storage devices.