PLEXOS 7.2 Release Notes
1. Upgrade Compatibility
This version will automatically upgrade any previous version 5-7 database. You may need to check the upgrade notes of earlier releases for any compatibility issues.
Databases in 7.2 format will retro-grade to any previous Version 7.x however please check upgrade compatibility notes for all previous versions.
2. Changes
The following are the changes to existing functionality between this version and 7.1:
2.1. Phase Shifter Class Renamed to Flow Control
The Phase Shifter class has been renamed to flow control and the features of this class expanded to model a greater variety of devices and support expansion in LT Plan.
2.2. Nash-Cournot Competition
The Nash-Cournot implementation has been revised. The Cournot objective is now fully integrated with the main simulation rather than being solved as a 'side problem'. This means that Cournot can be run in all simulation phases including LT Plan. The Competition settings Demand Scaling and Multi-period Equilibrium have been removed. MT Schedule is no longer required to run Nash-Cournot in ST Schedule.
Note that solving Nash-Cournot with integer problems will require Mixed Integer Quadratic Programming (MIQP). Currently this is supported only on the solver Xpress-MP and CPLEX.
3. Performance
A number of optimization have been made to the simulation engine and user interface codes which will improve performance especially in simulations that have a large number of steps/objects.
The following changes and/or new features specifically address performance of the simulation:
- The Xpress-MP solver is update Version 27.01.05
- The CPLEX solver is updated to Version 12.6.1
- The MOSEK solver is updated to Version 7.1.0.22
- The Gurobi solver is updated to Version 6.0.0
The setting Performance Cache Text Data in Memory has been moved to an undocumented parameter. This setting was designed to help on memory-constrained systems especially 32-bit systems, but it's effect on performance is so significant that it was decided to remove the option to avoid users accidentally switching it off.
4. Features
4.1. Flow Control
The Flow Control class replaces previous Phase Shifter class with enhanced features and flexibilities, to model different kinds of FACTs devices in transmission network. Flow Control objects can be included as expansion candidates in LT Plan and dispatchable resources in MT Schedule and ST Schedule.
4.2. Types of Transmission Right
Transmission Right settlement calculation has been extended with new Type and Pricing Method. The price components on both source and sink side of Transmission Right are reported separately now.
4.3. Time Zones
Time zones can be handled when reading data from text files with the Data File Time Shift property.
4.4. Dry Run Mode
The new setting Model Run Mode allows you to perform a "dry run" of a simulation whereby the simulation steps through but does not solve any of the optimization problems. This is useful for debugging inputs and settings.
4.5. Hydro Proportional Load Following (PLF)
This method implements the hydro modelling method adopted by the TEPPC in the WECC and is described in the documentation for their 2012 studies. PLF is implemented via the properties Generator Price Following, Load Following Profile and Load Following Factor.
4.6. Jump Diffusion
The jump-diffusion model is created by adding a jump term into the Brownian Motion with Mean Reversion model. This feature allows modeling jumpiness in generating random samples. Three parameters, jump frequency, jump magnitude and jump standard deviation, are required to describe the jump process. The GARCH (generalized autoregressive conditional heteroskedasticity) model is also available for the modeling of volatility clustering.
4.7. Database Change Management System
The new change system enable users to create and import changed database freely if the base database and changed database share the same ancestor. Any objects, memberships, attributes and properties can be merged. For further details on how to use the functions in PLEXOS GUI, please refer to Change System.
4.8. Series Statistics
A new statistics page is now available, which can be opened by clicking the "Statistics" button under the "Quick Chart" ribbon control, or by choosing "Statistics" in the right-click menu of solution execution results. This provides the user with details such as:
- Density Chart
- Average Value Chart
- Distribution Chart
- Detailed Statistics
Example:
Figure 1: Load Series Statistics
For further details about this feature then please go to the following link: Article PLEXOS7UserInterfaceGuideChapter12
5. New Inputs
New inputs are:
| Collection | Property | Description | Relates To |
|---|---|---|---|
| Generator | Include in Rounded Relaxation Merit Order | Flag if Generator is included in the Region merit order for Rounded Relaxation unit commitment | Unit Commitment |
| Generator | Price Following | Proportion of energy optimized, where the remainder is proportional load following | Hydro |
| Generator | Load Following Profile | Profile to follow for proportional load following | Hydro |
| Generator | Load Following Factor | Regression factor for proportional load following | Hydro |
| Fuel | Decomposition Method | Method used to pass the optimal stockpile trajectory from one simulation phase to the next | Storage |
| Fuel | Decomposition Penalty a | Decomposition stockpile target penalty function 'a' term | Storage |
| Fuel | Decomposition Penalty b | Decomposition stockpile target penalty function 'b' term | Storage |
| Fuel | Decomposition Penalty c | Decomposition stockpile c | Storage |
| Fuel | Decomposition Penalty x | Decomposition stockpile target penalty function x term | Storage |
| Fuel | Decomposition Bound Penalty | Penalty applied to violation of stockpile bounds when the decomposition implies possible violations | Storage |
| Gas Storage | Trajectory Non-anticipativity | Price for violating non-anticipativity constraints in scenario-wise decomposition mode | Stochastic |
| Gas Storage | Trajectory Non-anticipativity Volume | Volume of violation of non-anticipativity constraints in band | Stochastic |
| Gas Storage | Trajectory Non-anticipativity Time | Window of time over which to enforce non-anticipativity constraints in scenario-wise decomposition | - |
| Region | Wheeling Method | Export wheeling charge method | Power Flow |
| Zone | Wheeling Method | Export wheeling charge method | Power Flow |
| Flow Control | Price Setting | Flag if the flow control can transfer price across the network | Pricing |
| Flow Control | Expansion Optimality | Expansion planning integerization scheme | - |
| Flow Control | Type | Flow control type | - |
| Flow Control | Units | Number of installed units | On/Off Switches |
| Flow Control | Min Angle | Min angle | Popular;Capacity |
| Flow Control | Max Angle | Max angle | Popular;Capacity |
| Flow Control | Min Impedance | Min Impedance | Popular;Capacity |
| Flow Control | Max Impedance | Max Impedance | Popular;Capacity |
| Flow Control | Min Voltage | Min Voltage | Popular;Capacity |
| Flow Control | Max Voltage | Max Voltage | Popular;Capacity |
| Flow Control | Penalty | Penalty incurred for shifting the angle | Constraints |
| Flow Control | Angle | Angle (initial angle when used as input) | Constraints |
| Flow Control | Angle Points | Flow control angle points | - |
| Flow Control | Flow Loading Points | Flow control line flow points | - |
| Flow Control | FO&aml;M Charge | Annual fixed operation and maintenance charge | Fixed Cost;Capacity Expansion |
| Flow Control | Build Cost | Cost of building the flow control | Popular;Capacity Expansion'Fixed Cost |
| Flow Control | Project Start Date | Start date of the project, for expansion planning. | Capacity Expansion |
| Flow Control | Commission Date | Date the flow control was commissioned for use with [Technical Life] | Capacity Expansion |
| Flow Control | Technical Life | Technical lifetime of the flow control | Capacity Expansion |
| Flow Control | WACC | Weighted average cost of capital | Capacity Expansion |
| Flow Control | Economic Life | Economic life of the flow control (period over which fixed costs are recovered). | - |
| Flow Control | Max Units Built | Maximum number of units automatically constructed in aggregate over the planning horizon | Capacity Expansion |
| Flow Control | Min Units Built | Minimum number of units automatically constructed in aggregate over the planning horizon | Capacity Expansion |
| Flow Control | Max Units Built in Year | Maximum number of units automatically constructed in any single year of the planning horizon | Capacity Expansion |
| Flow Control | Build Non-anticipativity | Price for violating non-anticipativity constraints in scenario-wise decomposition mode | Capacity Expansion;Stochastic |
| Flow Control | x | Value to pass-through to solution | - |
| Flow Control | y | Value to pass-through to solution | - |
| Flow Control | z | Value to pass-through to solution | - |
| Transmission Right | Type | Type of transmission right | Pricing |
| Transmission Right | Pricing Method | Pricing method | Pricing |
| Variable | Jump Frequency | Jump frequency in Jump-diffusion model | Stochastic |
| Variable | Jump Magnitude | Jump magnitude in jump-diffusion model | Stochastic |
| Variable | Jump Error Std Dev | Percentage standard deviation of jump magnitude errors | Stochastic |
| Variable | GARCH alpha | Weight on the square of return | Stochastic |
| Variable | GARCH beta | Weight on the variance | Stochastic |
| Variable | GARCH omega | Long-run weighted variance | Stochastic |
| Constraint Variables | Start Hour Coefficient | Coefficient of the hour in the simulation the maintenance event started | - |
| Constraint Lines | Flow Back Coefficient | Coefficient of counter-reference direction flow | Power Flow |
| Constraint Lines | Flow Squared Coefficient | Coefficient of square of line flow | Power Flow |
| ConstraintLines | Build Cost Coefficient | Coefficient of total build cost | Capacity Expansion;Fixed Cost |
| Constraint Transformers | Flow Coefficient | Coefficient of transformer flow equation | Power Flow |
| Constraint Flow Controls | Angle Coefficient | Coefficient of flow control angle | Power Flow |
| Constraint Flow Controls | Positive Angle Coefficient | Boolean value (1 if the flow control angle is positive, 0 otherwise) | Power Flow |
| Constraint Flow Controls | Negative Angle Coefficient | Boolean value (1 if the flow control angle is negative, 0 otherwise) | Power Flow |
| Variable Generators | Units Sync Cond Coefficient | Coefficient of number of units running in synchronous condenser mode | - |
6. New Outputs
New outputs are:
| Collection | Property | Description |
|---|---|---|
| Generator | Marginal Fuel Cost | Short-run marginal cost fuel component |
| Region | Fixed Load | Fixed Load |
| Region | Fixed Generation | Fixed generation |
| Node | Fixed Load | Fixed load |
| Node | Fixed Generation | Fixed generation |
| Flow Control | Angle | Angle (initial angle when used as input) |
| Flow Control | Min Angle | Min angle set on the flow control |
| Flow Control | Max Angle | Max angle set on the flow control |
| Flow Control | Flow | Equivalent flow in reference direction due to phase shift |
| Flow Control | Flow Back | Equivalent flow against reference direction due to phase shift |
| Flow Control | Impedance | Equivalent impedance |
| FlowControl | Hours Binding | Number of hours the flow control is operating at maximum angle |
| Flow Control | Shadow Price | Shadow (expansion) price |
| Flow Control | Rental | Rental |
| Flow Control | Penalty | Penalty incurred for shifting the angle |
| Flow Control | Units Built | Binary indicating if the unit was built |
| Flow Control | Build Cost | Cost of new build |
| Flow Control | x | Pass-through value (summed in summary) |
| Flow Control | y | Pass-through value (summed in summary) |
| Flow Control | z | Pass-through value (averaged in summary) |
| Transmission Right | Source Price | Price on source side |
| Transmission Right | Source Energy Charge | Energy charge on source side |
| Transmission Right | Source Congestion Charge | Congestion charge on source side |
| Transmission Right | Source Loss Charge | Loss charge on source side |
| TransmissionRight | Sink Price | Price on sink side |
| Transmission Right | Sink Energy Charge | Energy charge on sink side |
| TransmissionRight | Sink Congestion Charge | Congestion charge on sink side |
| Transmission Right | Sink Loss Charge | Loss charge on sink side |
| Transmission Right | Price Delta | Price difference between the source and sink side |
| Variable | Volatility | GARCH volatility metric |