PLEXOS2PRAS

This repository provides tools to allow power system models formulated for PLEXOS to be read into NREL's Probabilistic Resource Adequacy Suite (PRAS). PLEXOS model specifications can be very complicated, so unfortunately the process for mapping them to PRAS inputs can be a bit involved as well! The following workflow aims to minimize the effort required:

Step 0: Installation

Follow the PRAS installation instructions to ensure your environment is ready to run both the PLEXOS2PRAS import tools and PRAS itself. Next, install PLEXOS2PRAS:

(v1.3) pkg> add PLEXOS2PRAS

Step 1: Represent your PLEXOS system in the Excel workbook format

If your system has been generated from ReEDS results, RPM results, or PIDG, it should already be available in this format.

If you only have the XML database file, you'll need to export your database via the PLEXOS GUI (File -> Export). Note that recent versions of PLEXOS have a bug that renders the Excel exports invalid for larger systems, so you may need to load your XML file in an older version of the PLEXOS GUI (7.2 or earlier) for this to work!

Step 2: Run the pre-PRAS worksheet modification utility

Once you have your PLEXOS system in an Excel workbook, run the workbook modification function from a Julia script:

using PLEXOS2PRAS
process_workbook("yourworkbookname.xlsx", "yourworkbookname_PRAS.xlsx")

This will create a new workbook file called yourworkbookname_PRAS.xlsx with changes to the system and output settings that are compatible with importing to PRAS. Note that if need be, you can also apply these changes manually in the PLEXOS GUI, and skip steps 1-3 here. For details, consult the worksheet modification reference.

The function takes two sets of optional keyword arguments. Unfortunately, due to limitations with PLEXOS passthrough variables, only one argument from each set can be true at a time.

Pumped hydro options:

pump_capacities: For Storage and GeneratorStorage resources loaded from PLEXOS pumped storage resources, should charge capacities be read in from the PLEXOS Pump Load property? Defaults to false, in which case the resources will be assumed to have symmetric charge / discharge capacities. If not using the default, be sure to provide the same option to the process_solution function later.

pump_efficiencies: For Storage and GeneratorStorage resources loaded from PLEXOS pumped storage resources, should charge efficiencies be read in from the PLEXOS Pump Efficiency property? Defaults to true. If false, the resources will be assumed to have 100% charge efficiency. If not using the default, be sure to provide the same option to the process_solution function later.

Battery options:

battery_availabilities: For Storage resources loaded from PLEXOS battery objects, should availability data be read in from the PLEXOS Forced Outage Rate and Mean Time to Repair properties? Defaults to false, in which case the resource will be assumed to have perfect availability (0% forced outage rate). If not using the default, be sure to provide the same option to the process_solution function later.

battery_efficiencies: For Storage resources loaded from PLEXOS battery objects, should efficiencies be read in from the PLEXOS Charge Efficiency and Discharge Efficiency properties? Defaults to true. If false, the resources are assumed to be 100% efficient. If not using the default, be sure to provide the same option to the process_solution function later.

Note that PLEXOS battery objects are particularly constrained by PLEXOS passthrough variables. There are six PLEXOS properties requiring passthrough (Capacity, Max Load, Charge Efficiency, Discharge Efficiency, Forced Outage Rate, Mean Time To Repair) but only three passthrough variables available (x, y, z). Because of these limitations, PRAS Storage resources imported from PLEXOS battery objects will always assume symmetric charge and discharge capabilities (i.e. the PLEXOS Max Load property will be ignored).

Step 3: Import the modified system back into PLEXOS

Import the modified system (yourworkbookname_PRAS.xlsx from the above example) into PLEXOS as you normally would. As with a normal import, you may want to use an empty template file.

Step 4: Run the PLEXOS Models that you want to import into PRAS

Run the relevant PLEXOS models (either via the GUI or CLI). The runs should finish much faster than normal since they're being executed in "dry run" mode, without solving for any decision variables. PRAS only needs PLEXOS' definition of certain inputs and constraints.

At this point, you can open the solution in the PLEXOS GUI and confirm that the results match your expectations. You can manually fine-tune properties in the newly-created database and re-run specific Models if you find elements that are unsatisfactory.

Step 5: Run H5PLEXOS and the solution processor

Once you have a PLEXOS zipfile containing results for the Model run you want to represent in PRAS, use H5PLEXOS.jl to convert it to an HDF5 files.

using H5PLEXOS
process("Model MyRun Solution.zip", "Model MyRun Solution.h5")

Step 6: Run the solution processor utility

Once each PLEXOS model result is processed into an HDF5 file, run the solution processing function from a Julia script to generate the corresponding PRAS model file.

using PLEXOS2PRAS
process_solution("Model MyRun Solution.h5", "mysystem.pras")

The function provides a number of optional keyword arguments, including two sets of mutually-exclusive options:

pump_capacities vs pump_efficiencies: Boolean values that determine how reported PLEXOS pumped storage properties should map to PRAS Storage and GeneratorStorage properties. The provided values should match the options set in the earlier process_workbook function call.

battery_availabilities vs battery_efficiencies: Boolean values that determine how reported PLEXOS Battery properties should map to PRAS Storage properties. The provided values should match the options set in the earlier process_workbook function call.

timestep: The length of a simulation timestep as a Dates.TimePeriod, e.g. Hour(1) or Minute(5). Defaults to Hour(1).

timezone: The TimeZones.TimeZone associated with PRAS system timestamps. Defaults to tz"UTC", although providing a more accurate value is recommended for clarity, especially if your system geography spans multiple time zones.

use_interfaces: Should interregional power transfer limits in PRAS be defined based on PLEXOS interface limits instead of the sum of interregional line limits? Defaults to false.

exclude_categories: A Vector{String} of PLEXOS generator category names that will be ignored/excluded when creating the PRAS model. Defaults to an empty list.

Step 7: Load into PRAS

You can now run PRAS as you normally would. After loading the PRAS module in Julia, the system representation stored in the .pras file can be loaded directly into a SystemModel struct:

using PRAS

# Load in the system
system = SystemModel("mysystem.pras")

# Assess the reliability of the system
assess(SequentialMonteCarlo(samples=100_000), Minimal(), system)