Transcript Potential Implications of PHEV`s on the scheduling of Electric

Potential Implications of
PHEV’s on the scheduling of
Electric Generation
Spinning Reserve
Bruce Wollenberg
Some basics of power system
operation

Generation must
equal load plus
transmission
losses (about 5%)
Frequency high
too much
power delivered
over tie lines
GENERATION
Frequency low
too little
power delivered
over tie lines
LOAD
Load + losses + Interchange
GENERATION vs. LOAD BALANCE
Some basics of power system
operation

What happens if a
generator fails?


When load is greater
than generation the
system slows down
If nothing is done the
system shuts down
completely
Frequency high
too much
power delivered
over tie lines
GENERATION
Frequency low
too little
power delivered
over tie lines
LOAD
Load + losses + Interchange
GENERATION vs. LOAD BALANCE
Some basics of power system
operation


We could remove
load when a
generator fails
This has been
proposed in California


Generator lost
Remove large water
pumping loads
Frequency high
too much
power delivered
over tie lines
GENERATION
Frequency low
too little
power delivered
over tie lines
LOAD
Load + losses + Interchange
GENERATION vs. LOAD BALANCE
Concept of Spinning Reserve
Enough generators are not loaded to
100%
 Loss of a generator can be made up with
remaining generators
 No load lost

Spinning reserve
Reserve
Spinning reserve
Spinning reserve
Spinning Reserve
Spinning Reserve costs money

Generation companies must be paid to
Run more generators than necessary
 Lower output on some generators to provide
reserve


Standard electric operation practice is to
supply sufficient reserve to withstand loss
of the largest generator and the second
largest generator
Unique possible contribution of
PHEV’s
Assume that when the PHEV is plugged in
there is also a data connection made to
the on board computer in the car
 Assume that future parking garages
provide for electrical/data connections for
PHEV’s during the daytime hours
 Control signals can be sent to cars to stop
charging, to generate off the car’s battery,
to generate using the car’s engine

PHEV’s actions in emergency
Charging
POWER FLOW
Step 1: stop
charging
Step 2:
Generate from
Battery
POWER FLOW
Step 2:
Generate from
Car engine
POWER FLOW
Numbers
Assume 100,000 PHEV’s
 Assume only 5 kW charging or generating
per vehicle
 Total when stopping charging 500 MW
(Mega watts)
 Total additional if generating 500 MW

Extra Costs
Power Electronics to take car battery
voltage and convert to 120/240 VAC
 Power/data connections in parking
garages
 Addition of data connection to power
connection in homes

The ideal marriage?