Hello,
I have been developing a control software for charging and discharging battery in a dc grid. The system consists of:
01) Three phase alternator with three phase diode bridge rectifier at its output (nominal power Pan)
02) Load with variable power consumption (current power consumption Pl)
03) Bidirectional battery charger
04) Battery (current charging or discharging power Pb)
(please see the attached circuit diagram)
The main goal of the control software is to determine the charging or discharging current of the battery and send this value into the battery charger. The logic behind this is following
01) if Pan > Pl then Pb = Pan - Pl > 0 and Icharger = Pb/Vdc_bus > 0
02) if Pan < Pl then Pb = Pan - Pl < 0 and Icharger = Pb/Vdc_bus < 0
The problem which I have been solving is how to evaluate the above mentioned power balance in case I measure only the dc_bus voltage (Vdc_bus).
I have started with a PID controller which maintains the dc_bus voltage at nominal voltage of the alternator and produces charging current for the battery charger. This idea works only in case the Pl = 0. In case the Pl starts growing up the controller forces the charger to start discharging
the battery resulting in equilibre state when the alternator operates with Pa < Pan and the battery is being discharged (which is of course undesirable state).
The question which I have is whether you mean that it is ever possible to determine the charging/discharging current based only on the dc_bus voltage?
I have been developing a control software for charging and discharging battery in a dc grid. The system consists of:
01) Three phase alternator with three phase diode bridge rectifier at its output (nominal power Pan)
02) Load with variable power consumption (current power consumption Pl)
03) Bidirectional battery charger
04) Battery (current charging or discharging power Pb)
(please see the attached circuit diagram)
The main goal of the control software is to determine the charging or discharging current of the battery and send this value into the battery charger. The logic behind this is following
01) if Pan > Pl then Pb = Pan - Pl > 0 and Icharger = Pb/Vdc_bus > 0
02) if Pan < Pl then Pb = Pan - Pl < 0 and Icharger = Pb/Vdc_bus < 0
The problem which I have been solving is how to evaluate the above mentioned power balance in case I measure only the dc_bus voltage (Vdc_bus).
I have started with a PID controller which maintains the dc_bus voltage at nominal voltage of the alternator and produces charging current for the battery charger. This idea works only in case the Pl = 0. In case the Pl starts growing up the controller forces the charger to start discharging
the battery resulting in equilibre state when the alternator operates with Pa < Pan and the battery is being discharged (which is of course undesirable state).
The question which I have is whether you mean that it is ever possible to determine the charging/discharging current based only on the dc_bus voltage?
