Analysis Tools: Pricing Module

This module contains the implementations of some of the methodologies used in the literature and by some countries, especially in Latin America, to determine the proportions and payments for the use of the transmission system in an electric system.

The main and common objective of all methodologies is to determine the percentage of use of a transmission line and thus, calculate the payment to be made by each market agent to the transmission system for the use of such system.

The available methodologies in Deep-Editor are:

1. GGDF without counterflow

2. GGDF with counterflow

3. GLDF without counterflow

4. GLDF with counterflow

5. GGDF Ley Corta (Chile)

6. GLDF Ley Corta (Chile)

7. Bialek’s method for generators

8. Bialek’s method for loads

9. Kirschen’s method

10. Postage stamp method

11. MWM method

12. Other methods proposed in Chile (sub-transmission, CNE, etc.)

General description

All methodologies have a common interface, the simulation functions can be accessed through the menu Simular Simulation->Yearly->Market->Transmission Pricing.

Figure 92: Menu to access Transmission Pricing

The way to run the simulation is similar for the different methods. Thus, this section demonstrates the use of the GGDF method for the Pricing simulation, although the concepts are generic and apply to the other methodologies.

When choosing the Via GGDF function from the Transmission Pricing menu, the TP GGDF Calculation Options window appears.

The window allows to choose which will be the first and the last dispatch of the simulation to provide the program with the simulation horizon.

Note: The selected limit dispatches must be included in the TPDB database, otherwise the simulation will be executed incorrectly.

It is also possible to choose between thermal or hydro-thermal scenarios. The simulation with purely thermal scenarios does not consider the different hydro conditions.

There is the option to provide reports, either in text file or in database. In the first case, the program creates a report named TPGGDF.dat with the result of the simulation, inside the subdirectory DEEP_EDIT_INSTALATION_FOLDER\results. In the case of choosing the option to create database, at the end of the simulation the program creates the database TPDBRes.mdb with the results in the subdirectory DEEP_EDIT_INSTALATION_FOLDER\database\.

Note: The program overwrites the information contained in the TPDBRes.mdb database (if previously existing). Then, if you want to keep the information from the previous result, you must make a copy of the TPDBRes.mdb database before re-running the simulation.

• The Calculate button starts the simulation process that consists in performing the DC power flows (without losses) for the considered evaluation horizon. Once the process of power flows for each dispatch (selected stages/hydro-conditions) is finished, the program will calculate the proportions according to the GGDF (or other method).

• The Cancel button cancels the simulation execution.

• The Go button does not run the simulation, it simply tells the program to read the information contained in the TPDBRes.mdb database.

The Extended Report checkbox allows you to create detailed reports for each dispatch, that is, for each dispatch it creates a text file with the flow information for each line and the toll that each generator pays for each line. For example, if you want to simulate a full year, as shown in Figure 93, the program will create 1440 text files, one for each dispatch, with names from 1.txt to 1440.txt respectively.

Figure 93: Calculation options window for the GGDF pricing simulation

Note: If no extremely detailed simulation information is required, it is recommended not to activate the Extended Report checkbox because the amount of time it takes for the simulation to run will increase with this option enabled due to the large amount of text files to be written.

The Transmission Pricing simulation can take several minutes, even hours, depending on the simulation horizon and the speed of the computer. The current version of the Deep-Editor does not show the progress of the calculation.

The Show Visualization Menu checkbox instructs the program to display the TP GGDF visualization parameters window which allows to control the relevant information to be displayed in the Network Editor after the simulation or data reading is finished.

Figure 94: GGDF method display parameters window

The transmission pricing information can be displayed by choosing one of 4 parameters and pressing the show button under the chosen parameter. These four parameters are “select generator”, “select line”, “select transformer” and “select supplier”. To choose these elements you can use the menus that appear in the window (see Figure 94) or click on the element in the Network Editor and press the select button for that element, for example if it is a generator press Select Generator.

If a generator is chosen, the lines that this generator occupies are painted in the Network Editor according to a color code related to a percentage of line usage. If a line or a transformer is chosen, all the generators that influence that element are painted in the Network Editor according to the same color code. If a supplier is chosen, all the lines that the generating stations of that supplier are on are painted in the Network Editor. Alternatively, you can select to show the effect on the lines of some power plants of that supplier.

Figure 95: Proportion display and color coding

In addition, at the end of the simulation, the program provides graphs with the proportion percentages corresponding to each generating company. These graphs are shown in the figures 96 and 97. Positioning the mouse pointer over a piece of the pie chart causes the value corresponding to the respective generating company to be displayed.

Figure 96: Pie chart of toll payment percentages by company obtained by simulation

Figure 97: Pie chart of toll payment percentages by company obtained by simulation

Input information

The input information comes from two sources:

1. Dispatch Database (TPDB.mdb): it contains the generation and consumption information based on which power flows will be performed and TP methodologies will be developed. It must be organized in two tables containing the active power injections and consumptions of the generators and consumptions respectively.

2. DeepEdit schematic: contains the topological information of the developed cases.

Dispatch database (TPDB.mdb)

The information of the dispatch database must be organized in a database of five tables

1. Generator: must contain the generations for each of the network generators for each case.

2. Demand: must contain the consumptions per node.

3. The other 2 tables (blockTime y SimInfo) must contain the simulation information (block definition and evaluation horizon information).

Figure 98: TPDB.mdb database structure

Generator table

The generator table must be named "generator" and should be organized in three fields, as shown in the following example.

Table 1: Generator table design

The three fields are:

• Name: It is of type "String" and contains the names of the generators.

• IdDesp: It is of type "Integer" and contains the number that identifies the dispatch.

• P: It is of type "double" and contains the active power injection in [MW] of the generators.

Demand table

The "demand" table must contain the information of the demands by busbars as shown in the following example.

Table 2: Demand table design

• Name: it is of type "string" and contains the names of the busbars with consumption.

• IdDesp: it is of type "integer" and contains the number that identifies the dispatch.

• P: is of type "double" and contains the active power withdrawal in [MW] of the consumptions (busbars).

Blocktime table

Contains the duration information of each block d1, d2, ..., dn. Each field indicates the number of hours in each block in which the evaluation horizon is divided. These values are used by the algorithm for the calculation of total annual energies and proportions.

Table 3: Blocktime table design

SimInfo table

Finally, the table containing the general information of the simulations should be named "SimInfo" and organized as shown in the following example.

Table 4: SIMINFO TABLE DESIGN: SIMULATION INFORMATION

• The "InitialYear" field is of type integer and indicates the year in which the generator table dispatches start to be coded.

• The "InitialMonth" field is of type integer and indicates the month in which the dispatches of the generator table start to be coded.

• The "YearNumber" field is of type integer and indicates the number of years to be considered by the simulation.

• The "MonthNumber" field is of type integer and indicates the number of months of the last year included in the data.

• The "BlockNumber" field is of type integer and indicates the number of blocks contained in each simulation month.

• The "HydroNumber" field is of type integer and indicates the number of hydrologies to be considered in the simulation.

Table 5: Example of information in siminfo table

The example in the table above defines a total of 2236 dispatches (or cases).

More details on the coding of the dispatches are explained in the following section.

Note: YearNumber and MonthNumber, defines the total number of months included in the horizon, so 1 year and 12 months is equivalent to 2 years and 0 months.

Logical data design

Dispatches are coded with a unique numbering for each combination of year, month, block and hydrology. As an example, let's look at the following case:

• 1440 dispatches

• 12 months

• 3 blocks for each month

• 40 hydrologies

Thus, the coding is given by the following formula.

Figure 99: Flow organization

Extraction of results

The reading of results is done directly from the reports delivered by the methodologies. Thus, the reading can be done from two sources:

1. Reading from text files: At the end of the routine and if a text file report has been selected, a file is generated in which the payment apportionment information by transmission elements is organized in columns.

The first column contains the name of the transmission element, the second column contains the name of the bus in the first part and in the second part the name of the company and finally in the last column there is the percentage proportion of payment by transmission elements.

This file is saved in the DeepEdit directory structure:

DEEPEDIT_INSTALATION_FOLDER\results\TP”Method”.txt, where “Method” is parametric and refers to the method chosen by the user.

Reading from database: Similar to reading from text file. However, a database has been built for all methodologies, each of which has its own table for both per member and per company apportionment.

This file is stored in the DeepEdit directory structure:

DEEPEDIT_INSTALATION_FOLDER \database\TPResDB.mdb

The information contained in the reports corresponds to a summary matrix, which contains the average proportion of payments for the use of lines and transformers according to the GGDF methodology (in analogous execution GGDF + counterflow, GLDF and GLDF + counterflow). Mathematically it is expressed as follows:

Where:

T = 7200

i = 1, ..., brannum

brannum = Total number of lines and transformers

j = 1, ..., nodnum

nodnum = Total number of busbars

= Average proportion of payment for line or transformer i of injection in j

= Proportion of payment per line or transformer i of the injection in j for flow t

The summary proportion by company or owner corresponds to a matrix of summary proportions, which is expressed as follows:

Where:

k = 1, ..., numowner

numowner = Total number of owners

= Active power generation of owner k at bus j for flow t

= Total active power generation at bus j for flow t

= Owner k's average proportion of payment for branch (line or transformer) i

Additional comments for the ley corta case

Additional tools

It is important to mention that in this section of the report, it is assumed that the reader is familiar with the methodology proposed by the "Ley Corta”.

A recalculation option has been added to the tools of the Ley Corta case, which is made possible by the creation of a binary file that saves the information of the annual simulation, and allows quick access to it, without the need to perform the calculation again.

Thus, the sequence to perform calculations is as follows:

1. Perform the calculation in the usual way, thus automatically generating the binary file associated with such simulation.

2. Access the menu again by choosing the recalculation option, as shown in the following figure.

Figure 100: GGDF ley corta configuration (note the additional menu "Recalculation Options”)

1. When pressing "Recalculate", the following menu will be displayed:

Figure 101: Ley Corta options window

1. The selection criterion is chosen:

• Upper Percentile: Division into percentiles of the flow modules per line.

• Percentage of Max Flow: Flows that exceed the selected percentage of the maximum flow per line.

1. The associated summary information is automatically displayed.

Special considerations for network construction

The direction of flows must be correctly defined in the construction of the network, i.e., the direction of flows must be defined in the direction of the busbar that is defined as the basic power substation. Thus, if the basic power substation were the Nogales busbar at 220 kV, then the direction of the flow direction of the line between Los Vilos and Nogales should be from Los Vilos to Nogales, as shown in the following figure:

Figure 102: Flow direction setting ley corta case