Load shedding

[B767300]

How can I simulate a load shed in PSX?

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GenEXT1: 000.0V          GenAPU1: 000.0V          GenAPU2: 000.0V          GenEXT2: 000.0V     
XPC1   : 000.0V          APB1   : 000.0V          APB2   : 000.0V          XPC2   : 000.0V     
                                SSB < : 000.0V       SSB > : 114.9V     
             Bus AC Sync Left: 114.9V                          Bus AC Sync Right: 114.9V
BTB1 t : 114.9V          BTB2 t : 000.0V          BTB3 t : 000.0V          BTB4 t : 000.0V     
BTB1 b : 114.9V          BTB2 b : 114.9V          BTB3 b : 114.9V          BTB4 b : 114.9V     
Bus AC1: 114.9V/59.59A     Bus AC2: 114.9V/164.49A     Bus AC3: 114.9V/133.39A     Bus AC4: 114.9V/90.59A
GCB1   : 114.9V/59.59A     GCB2   : 000.0V/0.0A     GCB3   : 000.0V/0.0A     GCB4   : 000.0V/0.0A
GenEng1: 114.9V          GenEng2: 000.0V          GenEng3: 000.0V          GenEng4: 000.0V     

p6A2   : 114.9V/10.01A     p6A11  : 114.9V/9.66A     p6A20  : 114.9V/20.57A     p6A29  : 114.9V/6.55A
p6A5   : 114.9V/3.39A     p6A14  : 114.9V/0.0A     p6A23  : 114.9V/0.0A     p6A32  : 114.9V/0.0A
TRU1   : 28.03V/13.95A     TRU2   : 27.99V/0.0A     TRU3   : 28.01V/0.0A     TRU4   : 28.02V/0.0A
Bus DC1: 28.03V/13.95A     Bus DC2: 28.03V/11.59A     Bus DC3: 28.03V/37.71A     Bus DC4: 28.03V/6.57A
DCIR1 b: 28.03V          DCIR2 b: 28.03V          DCIR3 b: 28.03V          DCIR4 b: 28.03V     
DCIR1 t: 28.03V          DCIR2 t: 27.99V          DCIR3 t: 28.01V          DCIR4 t: 28.02V     
                                        Bus Tie DC: 28.03V
p6K6 : 28.03V/12.63A   p6A9 : 28.03V/7.06A   p6B9 : 28.03V/0.0A   p6B10: 28.03V/0.0A
p6B5 : 114.9V/0.0A   p6B23: 114.9V/5.92A   p6B7 : 114.9V/0.0A   p6B11: 114.9V/7.87A
p6K8 : 28.03V/11.08A   p6A26: 28.03V/0.0A
IBVS Cpt: 114.9V/5.92A  Bus Xfer Cpt: 114.9V/5.92A  IBVS F/O: 114.9V/7.87A  Bus Xfer F/O: 114.9V/0.48A
Bus GH: 000.0V/0.0A  Bus GS: 114.9V/24.05A  T150: 27.97V/0.53A  Bus GS28AC: 27.97V/0.53A
Bat APU: 27.95V/0.0A   Bat MN : 27.96V/0.0A   Bat ISFD: 27.93V ChrgMode: 0 p7B25: 28.03V/0.0A
Disab APU: 114.9V/0.06A  Chrg APU: 27.98V/0.28A  Bus Hot APU: 27.98V/0.28A
Disab MN : 114.9V/0.1A  Chrg MN : 28.04V/0.43A  Bat Pole MN: 28.04V/0.43A  Bus Hot MN : 28.04V/0.43A
p6K1: 28.04V/0.43A  p6G9: 28.04V/0.0A
p6J7: 28.04V/0.0A  p6J9: 27.98V/0.28A  Xfer APU: 27.98V/0.28A
p6K2: 28.04V/0.0A  p6K3: 28.04V/0.0A  Bus M4534/R7687B: 27.98V/0.28A
p6J8: 28.03V/15.67A  p6K4: 28.03V/9.42A  p6K5: 28.03V/0.0A
Main Bat Rel C: 000.0V/0.0A  Main Bat Rel B: 000.0V/0.0A  Main Bat Rel A: 000.0V/0.0A
Bat Xfer Rel C: 28.03V/15.67A  Bat Xfer Rel B: 28.03V/9.42A  Bat Xfer Rel A: 28.03V/0.0A
Bus APU Bat: 28.03V/15.67A  Bus MN Bat: 28.03V/9.42A  m855m866: 28.03V/1.1A  m853: 28.03V/1.1A
p6B24: 114.9V/7.76A  p6A25: 114.9V/0.0A  Inv MN in: 28.03V/0.0A  Inv MN out: 000.0V/0.0A
Xfer MN Stby: 114.9V/7.76A  Bus MN Stby: 114.9V/7.76A
p6J6: 27.98V/0.0A  p6J5: 27.98V/0.0A  Xfr APU Inv: 000.0V/0.0A  Inv APU: 000.0V/0.0A
p6B26: 000.0V/0.0A  p6A8: 114.9V/0.0A  Xfer APU Stby: 114.9V/3.57A  Bus APU Stby: 114.9V/3.57A
Xfr Tow: 000.0V/0.0A  Inv Tow: 000.0V/0.0A  Tr Tow: 000.0V/0.0A
p6E22: 114.9V/0.54A  p6L1: 114.9V/0.0A  R7734b: 114.9V/0.41A  R7734a: 114.9V/0.27A  R7786d: 114.9V/0.27A
p6L2: 28.03V/0.37A  p6F24: 27.97V/0.0A 
BCU-1 in: 28.03V   BCU-2 in: 28.04V

vCount 19  aCount 51  dCount 15
According to a LH manual a single gen on the ground has a capacity of 305 amps for 5 seconds, is this [GCB1   : 114.9V/59.59A ] the respective gens amp output?

thx in adv

[Hardy Heinlin]

Electrical devices which use the utility busses are not explicitly modelled except for the APU starter and some fuel pumps (you can find their busses in the PSX manual with the search phrase "utility bus"). Other devices like oven, coffee makers etc. are not modelled, i.e. there are no sim controls or random functions for those less relevant devices. So you cannot model any specific load shedding in PSX.

Yes, "GCB1 : 114.9V/59.59A" indicates the voltage and amperage measured at the GCB 1 output.


|-|ardy

[B767300]

Other devices like oven, coffee makers etc. are not modelled

 maybe in PS11.... just kidding

Yes, "GCB1 : 114.9V/59.59A" indicates the voltage and amperage measured at the GCB 1 output.

It's been a long time since I've had electronics, but the other busses have a higher amp than the GCB 1 output due to them being connected in parallel? So in this case amp of GCB1+ACBUS2+3+4 = 305 A for 5 sec should initate the ELCU to load shed, or is there any other way to read the total amp on the used elec source?

Again I honestly forgot a lot I learned about serie, parallel etc.

[Hardy Heinlin]

In parallel, each generator still contains its own current and not the sum of all currents of all generators together. The relation between the distributed amperages depends on the inner resistance of each generator. It's like the impedance of loudspeakers in parallel. E.g. take a 4-ohm-speaker parallel with an 8-ohm-speaker: The one with the lower impedance will get a greater current. Speakers also function like electro-magnetic microphones and vice versa. Talk into one membrane, and the other parallel membrane will move with it. Generators also move with other parallel generators. They synchronise their motion. So, such a parallel system is always an interactive, interdependet system as each object is generating power as well as receiving power, but the sum is never in each object; the sum remains the sum of all objects.

As for the voltages: In PSX each power source incorporates an individual tiny little deviation from the theoretical standard voltage. This is intentional and realistic. You won't notice any special effects if GEN 1 in normal conditions provides 114.9 v instead of 115 v. But this individual value of 114.9 will help you to follow its distribution through the textual diagram. E.g. when an object Otto receives 114.9 v and object Paula receives 115.1 v, you know that Otto gets its current from GEN 1 while Paula gets it from another GEN which provides 115.1 v :-)


|-|ardy


Sorry, I misunderstood your question. Each AC bus contains its individual current because each bus powers different, specific devices. It would be a bizarre coincidence if every house in the street would consume exactly the same power. I now see you're confused because the text at GCB 1 indicates 59.59A instead of the sum of all four AC busses. This is just a simplification in the text; it indicates the origin of the algorithm which accumulates the amperage down the path. The text does not return the sum to the GSB 1 label. This text diagram is mainly intended for use as a debug tool for switch constellations, i.e. for relay and breaker states etc.

[B767300]

  Appreciate it, thx!

[John H Watson]

The 744 has a load sharing system to help reduce the strain on individual generators.





I assume this means that the genenerator output should be equal, but I have long since forgotten the theory and the real world values.