// creates a plan, with specified start time and state-of-charge
void createPlan(Tariff tariff, double initialCharging) {
needs = getFutureEnergyNeeds(start, size, initialCharging);
// update size to use all of last ShiftEnergy instance
int newSize = 0;
for (ShiftEnergy need : needs) newSize += need.getDuration();
size = newSize;
LpPlan plan = new LpPlan(tariff, needs, size);
usage = plan.getSolution();
slack = plan.getSlack();
updateNeeds();
}
// returns the ShiftEnergy array used to create the plan,
// decorated with the most recent solution
ShiftEnergy[] updateNeeds() {
if (null == needs) return null;
int usageIndex = 0;
for (int i = 0; i < needs.length; i++) {
ShiftEnergy se = needs[i];
se.setRecommendedUsage(
Arrays.copyOfRange(usage, usageIndex, usageIndex + se.getDuration()));
usageIndex += se.getDuration();
se.setSlack(slack[i]);
}
return needs;
}
// Computes energy use by chargers in the current timeslot.
// Remember that the plan has computed usage in terms of AC power,
// while the energy going into the batteries is lower by
// the chargeEfficiency value.
double useEnergy(double regulation) {
TariffSubscription subscription = getSubscription();
Tariff tariff = subscription.getTariff();
ensureCapacityPlan(tariff);
// positive regulation means we lost energy in the last timeslot
// and should make it up in the remainder of the shift
addEnergyCharging(-regulation * chargeEfficiency);
ShiftEnergy need = plan.getCurrentNeed(getNowInstant());
if (need.getDuration() <= 0) {
log.error(getName() + " negative need duration " + need.getDuration());
}
need.addEnergy(-regulation);
// Compute the max and min we could possibly use in this timeslot
// -- start with max and avail for remainder of shift
double max = nChargers * maxChargeKW * need.getDuration(); // shift
double avail = // for remainder of shift
nBatteries * batteryCapacity - getCapacityInUse() - getEnergyCharging();
double maxUsable = Math.min(max, avail) / chargeEfficiency;
double needed = need.getEnergyNeeded();
double used = 0;
RegulationCapacity regCapacity = null;
if (needed >= maxUsable) {
// we just use the max, and allow no regulation capacity
log.info(
getName()
+ ": no slack - need "
+ needed
+ ", max "
+ max
+ ", avail "
+ avail
+ ", dur "
+ need.getDuration());
used = Math.min(maxUsable, (needed / need.getDuration()));
regCapacity = new RegulationCapacity(subscription, 0.0, 0.0);
} else if (tariff.isTimeOfUse() || tariff.isVariableRate()) {
// if the current tariff is not a flat rate, we will just use the
// planned amout, without offering regulation capacity
// TODO - figure out how to combine variable prices with regulation
used = need.getRecommendedUsage()[need.getUsageIndex()];
regCapacity = new RegulationCapacity(subscription, 0.0, 0.0);
} else {
// otherwise use energy to maximize regulation capacity
double slack = (maxUsable - needed) / need.getDuration() / 2.0;
log.info(
getName()
+ " needed "
+ needed
+ ", maxUsable "
+ maxUsable
+ ", duration "
+ need.getDuration());
used = needed / need.getDuration() + slack;
regCapacity = new RegulationCapacity(subscription, slack, -slack);
}
// use it
addEnergyCharging(used * chargeEfficiency);
getSubscription().setRegulationCapacity(regCapacity);
log.info(
getName()
+ " uses "
+ used
+ "kWh, reg cap ("
+ regCapacity.getUpRegulationCapacity()
+ ", "
+ regCapacity.getDownRegulationCapacity()
+ ")");
need.tick();
need.addEnergy(used);
return used;
}