Features of Organization and Application of Active Balancing Cells with Extended Triggering Range of Shunt Circuits Keys in Ionistor Modules and Storage Devices of Joint-Stock Company “Elecond”

Abstract

The solution of the problem of the deficit of voltage level for the complete unlocking of MOSFETs used as keys in the shunt circuits of the cells of the active balancing of ionistor storage devices is given. In particular, a revision of the widespread two-pole circuit of the active balancing cell of the ionistor consisting of a comparison circuit and a shunt circuit with a key on the MOSFET is presented. The relevance of the problem is confirmed by the results of the analysis of the characteristics of the key MOSFETs at the level of the unlocking voltage of 2.5...2.7 V from the output of the comparison circuit. It is shown that this voltage is not sufficient to provide the channel resistance corresponding to a fully open transistor and the flow of the specified shunt currents in the entire range of external influencing factors (VVF), especially when exposed to a reduced temperature from plus 15 to minus 60 °C. The solution presented in the paper for finalizing the circuit of the active balancing cell is that voltage boost circuits are introduced between the comparison node and the shunt circuit. Their use allows you to increase the voltage at the gate of the key MOSFET by two, three, four, etc. times, which ensures the reliable operation of the shunt circuit key for different shunt currents. A special feature of the developed cell circuits is the three-pole switching, in which an additional output is connected to the adjacent ionistor cell. This method of switching on the developed active balancing cells provides doubling of the unlocking voltage on the gate and is sufficient for reliable unlocking of the key on the MOSFET at all shunt currents at the level of the charging voltage of the ionistors in the storage device 2.5...2.7 V. For shunt currents of the order of tens of amperes, it is shown that it is necessary to switch to a quasi-four-pole switching of the developed active balancing cell due to the separation of the supply power circuits (measuring circuits) of the comparison circuit and the power buses of the level-up circuit with the shunt circuit. The methods of switching on the developed cells that allow multiplying the unlocking voltage at the gate of the key MOSFET by three, four or more times are shown. The schemes and criteria for the necessity of applying such inclusion are given. Practical testing of the developed three-pole and quasi-four-pole active balancing cells, carried out on the ionistor NEE of JSC “Elecond”, showed satisfactory stability and performance under the influence of the entire set of VVF.