Foerfarande Foer att controllera and uppraetthaolla laddningen hos ett ac accumulatorbatteri i en reservestroemkaella och en reservestroemkaella

摘要

Under normal conditions a load 3 is energised from a main power supply 5 and a battery 1 is disconnected both from the load 3 and from a charger 7, the battery 1 being charged in response to its open circuit voltage falling to a minimum limit value (V1, Fig 3). Charging is also initiated after a mains interruption, and if the battery internal impedance increase to a predetermined level during discharge via an inverter 2 to load 3. The internal impedance is determined on the mains of the load current and the A.C. component of the battery voltage (which is due to the load current). Charging is initially effected at constant current until the battery voltage rises to a reference level, and then at constant voltage for a predetermined time (Fig. 3). An alarm is raised if the battery intense impedance increaser to the predetermined level during discharge to the load, and if self-discharge of the disconnected battery causes its open circuit voltage to fall to the limit value (V1) in too short a time (indicative of a faulty battery). Shutdown of the load 3 may also be initiated if the battery internal impedance increases to the predetermined level. IMAGE