# Presentation: 188352

## NuMI Beam line Power Supplies

- The supplies in the line is detailed
- Main Ring Style..........................1
- PEI/Transrex 500Kw...................10
- PEI 20Kw................................10
- PEI 240Kw................................2
- MI Correction elements..................6

- 7/11/01

**Notes:**
We us Transrex and PEI as the same generic name for large supplies.  
    This line will have both transrex and PEI supplies in the the line.
The line uses existing equipment which is being retro fitted and upgraded as needed. 7 PEI and 3 Transrex.
The correction elements are new MI style.  The channel elements for the correction elements are being constructed now.

## Transrex vs PEI 500Kw supplies

- 7/11/01

**Notes:**
The main difference between the two styles of supplies is the age.
Transrex supplies are 30 years Plus and the PEI  supplies are 20 years Plus.

A little more rework may be necessary for the Transrex supplies.  But they are operational now and can be installed as is.

Note: there are no PCB allow in the MI ring so any transrex supply with PCB caps in the snubbers circuits have been retro fitted with the new non-PCB style.

## Rework

- All of the PEI style power supplies have been modified and installed
- Controls cables are installed in MI60 and MI62 but final connection will completed after the data base is setup.

- 7/11/01

**Notes:**
Shown is the E:HV101 power supplies.
Modifications include
This loop has three supplies and a filter rack. So the door interlock switch status is brought out of each supply and the filter rack.  These switches and the safety system interlock will be summed in a permit chassis and will trip all the supplies if any door is opened.
This loop has a PLC installed to combine the control and status for all three into one connection to the controls system.  The PLC will monitor the door status a bypass all the supplies before the contactors open.

## Series Regulation

- The groups of supplies will be regulated by one current regulator.
- Each supply will have an SCR Unit with a closed voltage loop, the same as the single supplies.
- All the supplies act as if they are one.
- The supplies will all receive the same voltage reference.
- The P1 and A1 lines have this supply configuration in operations now.

- 7/11/01

**Notes:**
E:HV101
E:V110
E:V109

The two Horn power supplies are voltage sources and will not use current regulation but the controls will need a similar interface to offer the MCR and image that looks like one supply.

Only one of the SCR units in the group will have a current regulator installed.
   The current loop is adjusted to for higher voltage gain than a single supply.
    The power factor and Kva loading would be better if the supplies were brought on only when needed. Like the MI ring supplies.
    This would require a simple ramping computer to control the turn on,
      however the the ramp speed and ramp calculator overcomes the need for and intelligent ramping computer.

All the supplies receive the same voltage reference and act as if they are one voltage source.

We have two circuits in operation now with two supplies in series.

## Upgrades

- Reused “Main Ring SCR Unit”.
- Better Voltage control.
- Maintenance techs have experience and knowledge.
- Little or no down time due to these chassis.
- Need new current loop added to the chassis.
- Added a filtered voltage monitoring card to the chassis.
- New Gate Firing circuits.
- Two Quadrant operation. (Invert).
- Remove Diodes in the Bypass and add SCRs.

- 7/11/01

**Notes:**
The Main Ring power supplies had an FNAL designed closed loop voltage regulator installed in the resent past.
Better regulation. (two Voltage loops, fast and 120 Hz feedback.) 
More tech experience
Reliable operation.
Very Similar to the MI Ring voltage Regulator.
We need to add a current regulation loop with a PID loop for fast ramping.  For now this system is the same as the MI beamline but we are in the process of increasing the quality of the regulation in the MI and these change will be installed in NuMI supplies before the testing is complete.

The SCR Unit has 120 Deg extended pulses and the old system had 2uSecond pulse transformers 
The new gate circuit will support the extended pulses and avoid the need for double pulses to start the bridge caused by simple bypass SCR and bridge control.

All the firing circuits are installed in the PEI supplies.
The Voltage/current regulation chassis are installed in E:HV101.

## Ramp Calculator

- Each Load Will Use the Max P.S. Voltage.
- Operation will have only one data point to adjust.
- Same control as the P1,P2,P3 and A1 lines

- 7/11/01

**Notes:**
The speed of the ramp require the min of 64 points.
Only the Flattop Current needs to be adjusted by operations.
An application program exist for the P1,P2,P3 and A1 lines.
The NuMI line will be added to the program to have the same interface to operations.

The program optimizes the power supply voltage and RMS power into the load and RMS Kva on the feeders

Additional Information
The ramp works backwards from the extraction time and starts the power transfer in time to best use the supply voltage and line Kva.

## Power Supply Controls

- C468 Ramp Generators: Current Reference.
- Each magnet load will have one current reference.
- Voltage reference feed forward created by P.S. reg.
- L di/dt +IR and Integrator

- 7/11/01

**Notes:**
A current reference is supplied by the ramp generator to a closed loop current regulator.
The current regulator generates a feed forward voltage reference sent to the SCR Unit with a closed voltage loop.
(Ldi/dt +IR)  with a 30 Hz bandwidth.

## MI Regulation Improvements

- The C468 card’s DAC output has too much noise and drift.
- We are installing a local DAC in the current regulation system to improve the noise.
- The local DAC has better temperature drift numbers but is not in a better environment.
- Additional improvement will be installed as needed.
- Temperature regulation of the DAC.
- Flattop correction for magnet temperature. (JITTER)
- Low Beta/MI style Current regulator.
- BLB Learning system.

- 7/11/01

**Notes:**
We have been evaluating the operation of the MI P1 beamline supply I:hv703.

We are in the process of evaluating a new DAC for the current regulator.

We Plan to install this into the I:HV703 power supply loop in the P1 line as soon as we have enough time.

We will then install an improved reference in to all the NuMI regulators.

The strongest penalty for using the JITTER system is that the it will require a timing event to trigger the sample and hold for the correction.

## Series Power Supply Controls

- The reuse of existing equipment requires a series connection of two or three supplies on each of three magnet loops.
- The operations interface needs to be simple.
- Look like only one supply to the operations crews.
- Controlled turn on and off.
- Access for maintenance needs to be simple.

- 7/11/01

**Notes:**
One 600 volt @2500 amp loop.
One 400 volt @5000 amp loop.
One 800 volt @1250 amp loop.

The supplies are independent voltage sources that get summed into the load and controlled by one Current Loop.

There is a soft start in the current loop.  A PLC  is used to verify that all the supplies are turned on and off in the correct sequence.
  Requires that all the voltage loops close first before the current loop is closed.
  Requires that the current loop opens if any one of the supplies and bypass of the other supplies.
  The summations of trips and turn on order are controlled by a PLC to make it look like only one supply to operations.

Maintenance needs simple access 
   This is controlled by only one circuit breaker for all the supplies connected to one load.
       800 amps for each 600v@2500 amp load.
       1200 amps for the 400v@2500 amp load.
The door interlocks are hard wired together in addition to the filter rack doors through a permit chassis which will also sum the ESS system and then provide the safety permit into each  of the supplies.

## Beam Loss Issues

- The current regulation system has an absolute value circuit on the current error and will abort the beam in the MI if the supply is out of regulation.
- For the more critical loads an independent window detector will not allow the beam to leave the MI if the current is not within the window at flattop time.
- Two of the supplies have critical device controllers installed.

- 7/11/01

**Notes:**
All the supplies have current error detectors that abort the beam if the supply is not tracking the ramp.  
This will abort the beam on the NuMI cycles if any supply has a large error.
The controls system supports an analog alarm system which will use max and Min values to alert the operations crew.

Loads like the lambertson and C-magnets will have an extraction window detector installed that is independent of the supply and will check that the current is at the correct level.  
This will guard against a supply receiving an incorrect current reference, it will be in regulation but not at the correct current. The tighter the window the more difficult the tune up process.  The benefit of the window detector system it that it is not necessary for the ramp to track the reference all the way to flattop but only be in regulation during beam time.  Then the regulation during the ramp can be much less than at flattop but would require that the regulation abort not trip 

Two of the supplies in the line are critical devices which prevent beam from being transfer if the enclosures are not secure that can be affected by the beam.

## Present Status

- All the PEI supplies are installed.
- Five are installed at MI-60.
- The HV101 loop has 3 supplies in series.
- The Lam60 and V100 loops are single supplies. We expect to add filters later for improved regulation.
- A Main Ring style supply is being installed at MI-62 for the V105 loop.
- A single PEI is installed at MI-62 for the V110 loop. A filter will also be added to this loop.
- All the 20Kw quad loop power supplies are installed.

- 7/11/01

**Notes:**
The 105 loop would have been three PEI supplies in series but this would have overloaded the 1500Kva transformer for the MI ring.

## Present Status Continued.

- The smaller 20Kw supplies have had simple modifications and installed in MI-60 and MI-62.
- The digital status has been increased.  This will read back to the MCR all things that trip the supply.
- The MI ring uses this type of supply in the MI-8 line and the supplies being installed in the NuMI line will be brought up to the same level of controls.

- 7/11/01

**Notes:**
Simple changes to bring all the status out of the supply to the controls card.

Same level of controls improves the maintenance load.

## Pulsed Power Source

- The MI-62 power panel and transformer has enough unused equipment for all the NuMI supplies being added as a result of the addition of the Main Ring supply for the V105 loop.
- MI-60 has a new power panel installed but the 1,500Kva pulsed duty transformer has not been installed.
- All the line power and controls installations have been completed at both 60 and 62 with with the exception of the V105 supply. Civil construction needs to be completed before the transformer can be installed.
- All load connections will require extended MI access.

- 7/11/01

**Notes:**
The 480vac and 13.8Kva to the transformer can not be installed until an extended MI ring shutdown.
The main ring power supply transformer needs civil construction and installation.  The 13.8Kvac connection will need MI ring down time to connect.

Tunnel access for load installation and connection.

## Expected Completion of Supplies

- The supplies in the MI-62 and MI-60 building should be completed Sept 2000.  Assembly of the Main Ring supply cabinet has started but will not be able to be tested until the civil construction is complete.
- All the controls can/will be tested.  We have started the HV101 power supply controls testing.
- The Voltage regulation system can be tested using a temporary load.  The current regulation and filter testing will have to wait until the loads are connected.

- 7/11/01

**Notes:**
The 480 volt power may not be ready but all controls and low power can be tested early.

Start up studies will be needed after the magnets are installed.
  Analog current system will need start up time.

## NuMI Regulation Improvements

- Any improvements to the MI beamline regulation system will be added to the NuMI line supplies.
- The improved flattop regulation will be added after we have proven it in the MI lines.
- Improved current feedback in terms of DCCTs will be added as needed for each loop.
- The Low Beta/MI ring current regulation chassis will be added for even better current reference as needed.
- The BLB regulation system will be used only if necessary.

- 7/11/01