A method and an apparatus for equalising the voltages over the capacitors in a series connection of capacitors during charging and discharging

摘要

A method and an apparatus for equalising the voltages over the capacitors in a series connection of capacitors during charging and discharging. The apparatus comprises n+1 terminals (Q0-Qn) for connection to terminals (P0-Pn) of the individual capacitors (C1-Cn) in said series connection of said capacitors. It further comprises a series connection of two transistors (T1, T2; T2', T3'; T3, T4; ...) each with a trigger input (g1, g2, ...) connected between the outer terminals in each group of three successive terminals (Q0, Q1, Q2; Q1, Q2, Q3; ... Qn-2, Qn-1, Qn) and a diode (D1, D2; D2', D3'; D3, D4; ...) connected in anti-parallel with each said transistor. The common points between said series connected transistors (T1, T2;T2', T3'; T3, T4; ...) and the middle terminal in each said group of terminals are connected by means of an inductor (L1- Ln-1). A trigger signal generator is arranged having n signal outputs connected to each of said trigger inputs (g1, g2, ...) which generator delivers trigger signals to said inputs in order to switch said transistors from non-conducting to conducting state and vice versa