HyPS (Hybrid Power Systems) company builds energy systems for medium-sized vessels.
These are often hybrid combinations of battery banks (batteries), diesel generators and grid converters. On board the ship, the grid (a copper rod) is maintained at approximately 700 Volt voltage by the aforementioned suppliers. The grid also includes consumers, drive systems such as thrusters, but also lighting and heating.
Our engineer deals with the Battery Control System (BCS) and the umbrella Power Management System (PMS). The latter is responsible for the ‘accounting’ (how much power is available, how much is asked) and switching of suppliers and consumers depending on the situation.
The BCS consists of one or more Battery Sets, which consist of a converter, a Battery Monitoring System and a String of 4 to 6 modules (batteries). A module contains 24 cells.
All information from the BCS is sent via CAN messages to the BCS PLC (Bachmann).
From that, status and control messages are sent over Modbus TCP to the PMS (also a Bachmann PLC).
An important parameter for a battery system is the State Of Charge (SOC): how much% is the battery loaded. The CAN traffic is significant: hundreds of signals are exchanged from the battery system and the BCS converter. The converter gets setpoints that keep the voltage and current (during loading and unloading) in check.
Bachmann PLCs are special, because they are programmed by C ++!