• Topic ID: concept_lpl_gy5_1jb
  • Version: 2.0
  • Date: Oct 28, 2019 4:24:56 AM

Power-On Sequence

1 Functional Overview

Generator power on can be achieved by various ways depending on the system (console ON/OFF, PDU contactor).

In all cases, generator power on starts when input supply are applied to the generator.

NGPDU Power Unit will provide power mains supplies to Jedi60DC generator. System has two power supplies for Jedi60DC: LVAC and HVDC. It supplies all functions (kV generation, rotation of the anode, control).

HVDC ON/OFF is controlled by system firmware and only activated just before exposure.

LVAC is always active, 24/24h.

First of all, when 120 LVAC Low Voltage supply is powered-on, the low voltage power supply starts providing the +15V/-15V bus (Rotation Leds DS1/DS2 lighting).

The +15V rise triggers the 5V rise on the kV control, heater and rotation (Led DS3 lighting) boards.

2 Parallel Actions Upon Power-On

At this stage (LVAC and HVDC are powered on), many actions take place in parallel, as described in the subsections below.

note: Although these actions are listed in numbered sections below, all actions occur simultaneously during the power-on sequence.

2.1 kV control

  • software starts running the PRDs (Power Reset Diagnostics) (1s) (in case of error, Leds DS17 to DS24 display an error code)

  • software downloads the kV control FPGA and DSP which start regulating the inverter gate drivers supply (in case of error Leds DS17 to DS24 display an error code)

  • software checks the hardware configuration:

    • reads inverter identification

    • reads HV tank identification

    • reads system Interface identification

    • talks on Control Bus to identify the function present

2.2 Heater

  • microcontroller starts running the PRDs

  • then goes to the idle state

  • heater supply bus reaches its final value

2.3 Rotation

  • microcontroller starts by running the PRDs

  • then goes to the idle state

  • gates drive supply reaches its final value

  • DC Bus reaches its final value

2.4 Inverter

DC Bus reaches its final value on inverter LC and on gate drive supply

3 Once Main Functions Are Alive

Once each main function is alive, kV control:

  • checks the generator configuration consistency (in case of error, error message TBD is sent)

  • installs the right hardware drivers

  • talks to the system or the console (in case of no system/laptop presence detected, kV control Leds DS17-DS24 display an error code)

  • configures the final kV control FPGA

  • sends to rotation and heater their database based on the knowledge of the tube selected

4 End of Sequence

At this level, if no error has been detected, the generator is ready for the exposure procedure.