Monitoring the site power
programs used for
141009: switched to new 13kv line ao -> 129-> ao
170607: installed new main breaker in substation.
all measurements in time order:
170608: power outage. Voltage Phase->gnd
Monitoring the site power
A programmable breaker (ABB eVD4) was
installed in the power substation in mar13. This
breakersmeasures the power, voltage, currents .. at the input
to the substation. The information is queried and written to
disc once a minute. At 7:10 am every morning plots are made of
the power usage from the last 7 days. Once a month plots are
made for the entire month:
Power substation plots
for the last 7 days (.ps) (.pdf):
The plots are made once a day (at 7:10 am).
The data is sampled once a minute. The frames in
each plot are:
- Frame 1: power (Kilowatts)
- white: apparent power (Kvolts*Iamps) at input
- red: active power. This is the power used to do work.
- The plot is -Active power. The convention is an
inductive load is negative, a capacitive load is
- blue: minus the Reactive power
- Frame 2: Power factor:
- Active Power/Apparent power. It is negative since the
load is inductive.
- Frame 3: Current (amps)
- white: phaseA, red phaseB, blue phaseC
- solid line (what breaker calls instantaneous power)
- This looks like it has a threshold for measurement.
When the current changes by a certain amount a new value
- dashed line: 1 minute demand current provided by
breaker. Not sure whether this is a max or average.
- Frame 4: Phase to Phase voltage (Kilovolts)
- white phaseAtoB, red phaseBtoC, blue phaseCtoA
- Frame 5: Phase to ground Voltage (Kilovolts)
- white: phaseA, red phaseB, blue phaseC.
- Notes on the measurements
- The values reported by the browser screen
differ from these values by 1 or 2 %.
- The browser shows two types of values:
_INST_ and _DB_. I think the _DB_ values have been
- The analog input configuration section shows
some correction factors (.1 to 1.2%) for some
measurements (errors in a/d ?).
- I tried applying these corrections to the
_INST_ data and got values that were closer but not
exactly the same as those reported on the measurement
screen of the browser.
- In the end, the values shown in the plots have
not had any corrections made to them. they are the
_INST_ values from the breaker.
Programs used for the
- Program to read the breaker and output the data
- Writes to /share/phildat/sitepwr/sitepwr_yyyymmdd.dat
- This program runs on aserv11. If the computer reboots it
will probably have to be restarted (via)
- /share/megs/phil/svn/aosoft/src/sitepwrlog &
- Making the plots:
- sitepwrdaily.sc script run via phil's
crontab on megs3 to make the daily plots
- sitepwrdaiily.pro idl code to make the plots
Site power Documentation:
170608: Power outage. PhToGnd voltage->
The main breaker in the substation was
replaced on 07jun16. On 08jun16 the following occurred.
- 15:33 I restarted the monitoring of the breaker
- 15:34 power outage..
- 09jun17: 22:00 back to commercial power.
The plots show the recorded data for
this period (.ps) (.pdf):
- Data is sampled once a minute.
- The voltage data is sampled at the input to the breaker.
- Page 1: 08jun17 15:30 to 24:00
- Top frame: Phase to Phase voltages.
- Black Phase A to PhaseB voltage
- red Phase B to PhaseC voltage
- green: phase C to PhaseA voltage
- 2nd Frame: Phase to Ground voltages. (we must have a Y
- 3rd Frame: Current vs hour of day,. A blowup at the power
- We only had 1 complete sample before things started to
- After 2 minutes, the current had gone to 0.. The site must
have switched to the generators.
- Note. this gets done at 480Volts, after the
13kv has gone through the 13kv to 480V transformers.
- The breaker did not open during this period (all of the
voltage protection in the breaker is currently disabled).
- Bottom frame:
- A blowup of the phase to ground voltages at the power
- Page 2: 09jun17 00:00 to 12:00
- The site was on the generators the entire time.
- The substation breaker and the transformers 13kv ->
xx were still energized, but they supposedly did not have any
- Top: phase to phase voltages
- bottom: phase To ground voltages.
- 9:30 enoc opened the breaker (manually).
- The phaseA to Ground voltage went from 12KV to 0 volts.
- The other 2 phases remained unchanged.
- Phase A voltage to ground did the following:
- 7.8 kv
- Load starts to drop:
- PhtoGndV -> 13KV for 7 minutes
- the load was 0 after about 2 minutes
- PhToGndV 13Kv -> 3.5Kv.. stayed there for about 15
- PhToGndV 3.5Kv -> 12KV. stayed there till 09:30 the
- 09:30 main breaker manually opened. PhToGndV 12Kv
- The breaker is a 13KV breaker. This is for the phase to phase
- We were putting 13KV between phase A and the common connection
of the Y.
- I wonder if the breaker is setup to handle this voltage?
- When the breaker was opened, PhaseA voltage to ground went
from 12KV to 0v.
- The 12KV must have been coming from the AO side of the
Breaker.. since opening the breaker, the input voltage went to
- could the 430 recloser have been closed, and the 430
transformer (13kv -> 4160) was still connected to the
- Do we have some other problem with the components on the AO
side of the breaker for PhaseA?
- It would probably be a good idea for us to get the
substation programmed to open when we have voltage differences
- It could then protect things on the AO side of the breaker.
- When doing this, we need to keep in mind:
- Would every power outage cause the breaker to open? Will
- What would happen during a lightning strike?
- If the breaker does open, then our transfer switch won't
be able to switch back to public power until the breaker is