Abstract: Power supply system, such as power battery pack and fuel cell,normally uses a series-type power supply structure, and the voltage parameter of battery is an important performance index of the battery. A bus-type voltage acquisition system is designed. In the system, the photoelectric relay is adopted to load a battery on the measurement bus, and the voltage monitoring is implemented by means of the logic control of shift register 74HC164. Thus the consistency of the overall measurement is improved through single signal processing and isolation circuit. The number of components is reduced, and the circuit structure and control procedure are optimized compared to logic circuit with decoder. The modularization and scalability of the measurement system are achieved by PIC18F2580 minimum system and CAN bus interface. The experimental result shows that the system has stable performance and meets the requirement of measuring accuracy, which has been used for the voltage monitoring of 3 kW and 10 kW fuel cells.

Key words: electrical engineering, power battery pack, fuel cell, measurement bus, voltage acquisition, dynamic loading