PhD Thesis - Cranfield University

Chapter 6
With reference to the PES structure described in Chapter 5, the start-up and shutdown
procedure mandatory for the safe operation of the vehicle power system was also
implemented within the control system. Before entering State 000, the controller executes
essential preconditioning of the power system. Most importantly, the precharging of both
the DC bus and the ultracapacitors require supervisory control to limit large inrush currents.
Similarly, a shutdown sequence returns the power system to a safe mode before exiting state
000. Figure 6.6 illustrates these sequences. In the diagram refers to the main
controller enable signal (Master switch).
=1
Batt SoC_OK
Pwr_Elect _OK
=0
000
Initialise
On
Permissive
DAQ_OK
Traction_OK
Prechg. DC bus
Power = 0_OK
Open UC circuit
Open DC bus
Start up sequence
Initialise
Shut down sequence
171
Start
Permissive
Precharge UC
Reset Batt SoC
Reset UC SoC
Shut down
Figure 6.6 Start-up and Shutdown sequence
Run
Permissive
000