Time-series EV demand — get

Obtain time-series of EV demand from sessions data set

Usage

get_demand(
  sessions,
  dttm_seq = NULL,
  by = "Profile",
  resolution = 15,
  mc.cores = 1
)

Arguments

sessions: tibble, sessions data set in standard format marked by {evprof} package (see this article)
dttm_seq: sequence of datetime values that will be the datetime variable of the returned time-series data frame.
by: character, being 'Profile' or 'Session'. When by='Profile' each column corresponds to an EV user profile.
resolution: integer, time resolution (in minutes) of the sessions datetime variables. If dttm_seq is defined this parameter is ignored.
mc.cores: integer, number of cores to use. Must be at least one, and parallelization requires at least two cores.

Value

time-series tibble with first column of type datetime

Details

Note that the time resolution of variables ConnectionStartDateTime and ChargingStartDateTime must coincide with resolution parameter. For example, if a charging session in sessions starts charging at 15:32 and resolution = 15, the load of this session won't be computed. To solve this, the function automatically aligns charging sessions' start time according to resolution, so following the previous example the session would start at 15:30.

Examples

suppressMessages(library(lubridate))
suppressMessages(library(dplyr))

# Get demand with the complete datetime sequence from the sessions
sessions <- head(evsim::california_ev_sessions, 100)
demand <- get_demand(
  sessions,
  by = "Session",
  resolution = 60
)
#> Warning: charging sessions are aligned to 60-minute resolution.
demand %>% plot_ts(ylab = "EV demand (kW)")


# Get demand with a custom datetime sequence and resolution of 15 minutes
sessions <- head(evsim::california_ev_sessions_profiles, 100)
dttm_seq <- seq.POSIXt(
  as_datetime(dmy(08102018)) %>% force_tz(tz(sessions$ConnectionStartDateTime)),
  as_datetime(dmy(11102018)) %>% force_tz(tz(sessions$ConnectionStartDateTime)),
  by = "15 mins"
)
demand <- get_demand(
  sessions,
  dttm_seq = dttm_seq,
  by = "Profile",
  resolution = 15
)
#> Warning: charging sessions are aligned to 15-minute resolution.
demand %>% plot_ts(ylab = "EV demand (kW)")