evcc-io/core/wrapper/socestimator.go

130 lines
3.9 KiB
Go

package wrapper
import (
"errors"
"math"
"time"
"github.com/andig/evcc/api"
"github.com/andig/evcc/util"
)
const chargeEfficiency = 0.9 // assume charge 90% efficiency
// SocEstimator provides vehicle soc and charge duration
// Vehicle SoC can be estimated to provide more granularity
type SocEstimator struct {
log *util.Logger
vehicle api.Vehicle
estimate bool
capacity float64 // vehicle capacity in Wh cached to simplify testing
virtualCapacity float64 // estimated virtual vehicle capacity in Wh
socCharge float64 // estimated vehicle SoC
prevSoC float64 // previous vehicle SoC in %
prevChargedEnergy float64 // previous charged energy in Wh
energyPerSocStep float64 // Energy per SoC percent in Wh
}
// NewSocEstimator creates new estimator
func NewSocEstimator(log *util.Logger, vehicle api.Vehicle, estimate bool) *SocEstimator {
s := &SocEstimator{
log: log,
vehicle: vehicle,
estimate: estimate,
}
s.Reset()
return s
}
// Reset resets the estimation process to default values
func (s *SocEstimator) Reset() {
s.prevSoC = 0
s.prevChargedEnergy = 0
s.capacity = float64(s.vehicle.Capacity()) * 1e3 // cache to simplify debugging
s.virtualCapacity = s.capacity / chargeEfficiency // initial capacity taking efficiency into account
s.energyPerSocStep = s.virtualCapacity / 100
}
// RemainingChargeDuration returns the remaining duration estimate based on SoC, target and charge power
func (s *SocEstimator) RemainingChargeDuration(chargePower float64, targetSoC int) time.Duration {
if chargePower > 0 {
percentRemaining := float64(targetSoC) - s.socCharge
if percentRemaining <= 0 {
return 0
}
// use vehicle api if available
if vr, ok := s.vehicle.(api.ChargeFinishTimer); ok {
finishTime, err := vr.FinishTime()
if err == nil {
timeRemaining := time.Until(finishTime)
return time.Duration(float64(timeRemaining) * percentRemaining / (100 - s.socCharge))
}
if !errors.Is(err, api.ErrNotAvailable) {
s.log.WARN.Printf("updating remaining time failed: %v", err)
}
}
// estimate remaining time
whRemaining := percentRemaining / 100 * s.virtualCapacity
return time.Duration(float64(time.Hour) * whRemaining / chargePower).Round(time.Second)
}
return -1
}
// RemainingChargeEnergy returns the remaining charge energy in kWh
func (s *SocEstimator) RemainingChargeEnergy(targetSoC int) float64 {
percentRemaining := float64(targetSoC) - s.socCharge
if percentRemaining <= 0 {
return 0
}
// estimate remaining energy
whRemaining := percentRemaining / 100 * s.virtualCapacity
return whRemaining / 1e3
}
// SoC implements Vehicle.ChargeState with addition of given charged energy
func (s *SocEstimator) SoC(chargedEnergy float64) (float64, error) {
f, err := s.vehicle.ChargeState()
if err != nil {
s.log.WARN.Printf("updating soc failed: %v", err)
// try to recover from temporary vehicle-api errors
if s.prevSoC == 0 { // never received a soc value
return s.socCharge, err
}
f = s.prevSoC // recover last received soc
}
s.socCharge = f
if s.estimate {
socDelta := s.socCharge - s.prevSoC
energyDelta := math.Max(chargedEnergy, 0) - s.prevChargedEnergy
if socDelta != 0 || energyDelta < 0 { // soc value change or unexpected energy reset
// calculate gradient, wh per soc %
if socDelta > 1 && energyDelta > 0 && s.prevSoC > 0 {
s.energyPerSocStep = energyDelta / socDelta
s.virtualCapacity = s.energyPerSocStep * 100
s.log.TRACE.Printf("soc gradient updated: energyPerSocStep: %0.0fWh, virtualCapacity: %0.0fWh", s.energyPerSocStep, s.virtualCapacity)
}
// sample charged energy at soc change, reset energy delta
s.prevChargedEnergy = math.Max(chargedEnergy, 0)
s.prevSoC = s.socCharge
} else {
s.socCharge = math.Min(f+energyDelta/s.energyPerSocStep, 100)
s.log.TRACE.Printf("soc estimated: %.2f%% (vehicle: %.2f%%)", s.socCharge, f)
}
}
return s.socCharge, nil
}