Release Notes
- EMO 4.11.2 Released 2-May-13
- Bug fixed in demand profile import for Power Flow mode
- Bug fixed in generation profile import for Power Flow mode
- EMO now automatically checks for new grid and reserves data when you start the program (if you leave EMO running overnight then you need to check manually when you come back to it)
- The File Inputs window EMO now shows the date to which input data is believed to be valid
- If you select a day in Market view for which EMO believes there is incomplete data, then "Incomplete Data" will show in read near the top left corner of the Main window. Hover over this and it shows the date to which inputs are available. Click on this and it opens the File Inputs window.
- EMO Help will now take you to this new wiki on the web. The wiki replaces the old online help and the user manual. It is easier and cheaper to maintain than the old manual and help material.
- We advise you check that the excluded items (see the Edit menu) include the following 8 wind farms: MAH, NZW, TAP, TUK, TWC, TWF, WHL, WWD
- Also check that the constraints DCSA_BenP1Aout, DCSA_BenP1Bout, DCSA_HayP1Aout, DCSA_HayP1Bout are excluded.
- EMO 4.11.2 is available at http://www.ellsoft.co.nz/downloads/emo/installemo4.11.2.zip
- The password is available for licensed users from Matt.Woods@energylink.co.nz ddi 03 474 9379.
- EMO 4.10.4 Released 30-Oct-12
- There was a bug in EMO 4.10.3 when loading demand data into a Forecast from a file. EMO would halt with an exception notice from which clicking Continue would not recover. The bug was caused by an array which overflowed when reading the demand from the csv file.
- EMO 4.10.3 Released 31-Jul-12
- Quote of the year from Matt Woods, our Development Manager: “it’s like wading through mud” as he referred to the difficulties he experienced interpreting the data in the SPD daily case data files from which we now extract reserves, grid and constraint data. A long process, but we’re pretty much there now and Matt has even developed a nice developer’s utility for analysing the daily case data.
- The result is that EMO 4.10.3 is now ready for release in beta version (which means that our users need to perform their own testing before it can be confirmed as a final version before it can be confirmed as a final release).
- Previous Release (EMO 4.8.2) will not be Supported Much Longer
- The previous version release in Dec-11 uses a slightly different update mechanism for updating the grid and reserves inputs data files, which won’t be supported once all users on the latest version EMO 4.10 .3. For that reason, we want to get all users onto 4.10.3 as quickly as possible.
- Changes in the new version are listed below.
- Input Data
1. Full grid data is available back to 16 July 2009 using the new data from the SPD daily case files (and prior to that using the old grid format data).
2. Full reserves data is also available back to 22 July 2009 (but not prior to that date).
3. Additional constraints associated with frequency keeping generators (constraining them up or down so that they operate within their FK range) are now captured and available in the constraints files.
4. Additional constraints associated with line outages are now captured and included in the constraints files.
5. The grid and reserves files will be updated most business days.
6. Items 1 – 5 above mean that EMO will be ready to solve the market without any manual input of reserves data or additional constraints.
- To get the latest data files, use File>File Inputs
- Go to the Download tab and click on the button labelled Check for New Files. If you have any problems with this, please contact Matt.
- Really Useful Changes to the User Interface
7. When you create a Scenario EMO will remember whether you last solved with or without reserves, and offer this as the default.
8. You can now add items to Watch Lists from all windows (not just from the map), e.g. right click on a row of offers in the Units window, or on an equation constraint in the Constraints window, and add it to a watch list.
9. The Data Sources window (lower right hand corner, where you see Market, Forecasts, Powerflows and Scenarios in a folder structure) has the ability to filter what you see in this window down to a particular day or trading period. This makes it easier to work with Scenarios and Forecasts.
10. Use Ctrl-Shift-C to copy data and column headings onto the Clipboard.
Other Improvements
11. We’ve started on making improvements to the way the HVDC link is modelled. We had hoped to get all of the changes in this release, but some more subtle changes are required and will be released later.
12. The performance of the solver was improved to handle the many additional constraints now included in the grid, constraints and reserves files.
13. A few bugs were found and fixed including handling of constraints on the HVDC link.
- Important Information About Solves (Forecasts and Scenarios)
- Where there are differences between solves produced by EMO and SPD, these are now likely to be caused by:
1. your input data being wrong or incomplete: this is the single biggest cause of problems with EMO’s solves, and if you have any doubts about your inputs, or which inputs to use, please feel free to call us to discuss;
2. your input data being wrong or incomplete (just repeating this for emphasis);
3. the handling of the HVDC link in EMO is slightly different to the handling in SPD;
4. there is a known issue with EMO’s pricing (but not dispatch) in some cases when a constraint creates a very large price difference across some parts of the grid;
5. EMO is a non-linear model (and hence models losses as quadratic losses) whereas SPD is a linear model and has to approximate quadratic losses with linear losses.
- EMO 4.8.2 Released 23-Dec-11
- This version is no longer supported as it is superseded by EMO 4.10.4.
- Grid Data
- There is a new file for VLRs which, during the VLR trial, will be created manually. When we know what format they will be delivered in on a permanent basis, then the new formatted will be handled in EMO and data capture automated. There is a limitation with the VLRs in this EMO version:
- note that DST changes are not handled exactly using these trial ratings;
- There is a new window for grid data, accessed from File Menu>Grid Data:
- this used to be accessed from File>Data Sources;
- this is the window where you now go to download new grid files;
- this window shows when the default ratings are valid and whether they ratings follow a SSW (summer shoulder winter) or VLR (variable line rating) scheme;
- click on the Download EMO Grid Files button to check for and load new grid files;
- the Use File Sourced Grid button is currently disabled, but files are used anyway;
- the table shows the dates and trading periods (Valid from and Valid to) between which the latest default ratings apply.
- Double click on any line in the table to see the default ratings that apply.
- For VLR lines:
- the table shows 6 MW capacity values and 5 TP (trading periods)
- the MW capacity in the first column applies from TP 1 to the 1 TP before the TP shown in the first TP column, and so on, e.g. “400 15 367 19” would mean 400 MW from TP 1 to 14, 367 MW from TP 15 to 18, and so on;
- For SSW lines the shows the summer, shoulder and winter ratings that apply;
- The Reratings tab shows a limited history of re-ratings that reflect outages or partial outages on the line, as represented in the new grid data files;
- The Dec row may not display correctly (known bug) but nevertheless the VLR ratings are applied correctly in EMO.
- For VLR lines:
- Re-ratings changes:
- EMO now distinguishes changes in the default ratings (SSW or VLR) from other re-ratings, which will make the new re-ratings file smaller;
- even with the new grid files, there is no way of knowing if an outage present in the last few tradings periods in the file will persist, e.g. the permanent split between FHL and WPW. As a solution, any line in an outage (capacity = zero) for the last 48 trading periods in the grid files is assumed to be in outage into the future;
- Delays in getting grid data: users have noted delays of up to 10 days in getting the raw SPD final pricing case data posted on the EA’s web site, which apparently occurred due to the need to handle files manually. But the EA advised us that the process would be automated and the data available from an FTP server: this has now happened. We are working through re-automating the capture process at our end, and this will be completed early next year;
- refreshing grid files: if you think your grid files are corrupt (perhaps you opened one in Excel, modified it and then saved it again), the easiest solution is to delete the file(s) and then get EMO to check for new files from the File Menu>Grid Data window (click the Download EMO Grid Files button).
- Demand Data
- Our recommendation for demand data continues to be to use the SPD demand data from WITS. Find this by logging onto WITS and selecting GXP Demand from the Market Data menu. To get accurate solves in EMO which mirror final prices, you must select Final as the Price Type. You will also need to do a multiple selection to get all nodes.
- BE WARNED - this data appears to be provisional in many cases and is often updated when final prices are published, so you need to make sure that you have the latest data that is consistent with final prices.
- BE WARNED AGAIN - if you use any other data set, then you may not get accurate solves with EMO. In many cases, small changes in demand make a big difference to the solve.
This data is what is used in SPD for solving final prices. It is gross demand with some important exceptions:
- wind farm output is netted off GXP/GIP demand. At grid-connected wind farm GIPs, therefore, you will find either negative or zero values. At GXPs with embedded wind farms you will find positive and sometimes also negative values, depending on whether or not the wind farms cause export to the grid;
- generation under 10 MW has a blanket exemption from offering so is netted off GXP demand, in the same way as embedded wind farms.
There are two key aspects to getting the demand right: one is to use the correct demand data, as described above, but the second is ensure that you are not double counting any generators. Whereas generation under 10 MW is not offered and therefore won’t have offers appear in the daily offer data, wind farms over 10 MW do offer and their offers do appear in the daily offer data. If you don’t remove the wind farm offers then you will double count their output in your solves. Solution: make sure you use the demand data described above, and then also exclude all wind farms by going to Edit>Excluded Items. As of this date, the excluded items should include the following:
Embedded Generators Excluded Equations NZW DCSA_BenP1Aout TAP DCSA_BenP1Bout TUK DCSA_HayP1Aout TWF DCSA_HayP1Bout WHL WWD
The wind farms above are NZ Windfarms Te Rere Hau, Te Apiti, te Uku, Tararua Windfarm, White Hill and West Wind. The excluded equations above relate to the HVDC link and are not required by EMO.
Enhancements
- The offers that you can change in a Scenario are shaded in a much brighter yellow which makes them easier to see on a laptop screen.
Bug fixes:
- the offers graph Edit>Supply & Demand>Offer Graph now loads much quicker
- detection of an infeasible solution was improved to reduce the occurrence of false infeasibilities.