Civil Engineering Reference
In-Depth Information
•
excessive gassing and heating, leading to a short life.
•
unpredictable premature failure leading to loss of load availability.
•
positive plate corrosion shortening the life.
•
stratification and sulfation degrading the performance.
The following features incorporated in the battery management can avoid
the above problems:
•
controlled voltage charging, preferably at constant voltage.
•
temperature-compensated charging, in that the charge termination
occurs earlier if the battery temperature is higher than the reference
temperature.
•
individual charge control if two or more batteries are charged in
parallel.
•
accurate set points to start and to stop the charge and discharge
modes.
10.9.1
Monitoring and Controls
The batteries in modern power systems are managed by dedicated computer
software. The software monitors and controls the following performance
parameters:
•
voltage and current.
•
temperature and pressure (if applicable).
•
ampere-hour in and out of the battery.
•
state of charge and discharge.
•
rate of charge and discharge.
•
depth of discharge.
•
number of charge and discharge cycles
The Ah integrating meter is commercially available, which keeps track of the
Ah in and out of the battery and sends required signals to the mode controller.
The temperature compensation on the maximum battery voltage and the
state-of-charge can improve the battery management, particularly in extreme
cold temperatures. It can allow additional charging during cold periods
when the battery can accept more charge. The low voltage alarm is a good
feature to have, as excessive discharging below the threshold low voltage
can cause cell voltage reversal, leading to battery failure. The alarm can be
used to shed noncritical loads from the battery to avoid battery damage.
Figure 10-20
depicts a commercially available battery management system
incorporating a dedicated microprocessor with software.
