Phase Shifters and DC ties in the IDC

Transcription

1 Phase Shifters and DC ties in the IDC June 2009 Version Summary Setup and Use of Phase Shifters in IDC Modeling Requirements for Phase Shifters Submittal of etags over Phase Shifters IDC Use of Phase Shifters in Regulate Mode IDC Use of Phase Shifters in Non-Regulate Mode IDC Use of Phase Shifters in Bypass Mode Entering Phase Shifter Data Phase Shifter Summary Screen Phase Shifter Detail Screen Entering Data: Tap Position and Data Source Entering Data: Regulation Status Entering Data: Schedule Distribution Percentage Viewing Phase Shifter Data in the IDC DC Ties in the IDC Modeling Requirements for DC Ties Submittal of etags over DC Ties...12 Record of Revisions Version Date Changes 0 June 2009 Original 1

2 1.0 Summary This document contains three sections. The first describes how the IDC uses phase shifters in the modeling. The second section provides user information on how to update the phase shifter information within the IDC. The third provides information on how the screens in the IDC might look different when phase shifters are actively modeled in the IDC. 2.0 Setup and Use of Phase Shifters in IDC This section describes how the settings selected for the phase shifters impact the modeling within the IDC. The different settings will impact how the schedules are modeled and impacted by TLRs. There are two scenarios possible to describe interfaces containing phase shifters. The first scenario is that all tie lines on that interface contain phase shifters. The second scenario is that there is a mix of phase shifters and normal A/C tie lines. While some description is provided in this document for the second scenario, this would be a complex implementation and should be considered further before implemented in the production IDC. The focus of this description is on the first scenario and the specific modeling that occurs over the phase shifter itself. An example of Scenario 1 is the interface between ONT and DECO (Michigan). There are four ties between ONT and DECO, all of which have phase shifters. An example of Scenario 2 is the interface between ONT and NYISO. There are six ties between ONT and NYISO, four of them are free flowing and two of them have phase shifters. Since the entire interface is scheduled together and the schedule of the phase shifters is not monitored separate from the free flowing ties, it does not make sense to model the phase shifters in the IDC Modeling Requirements for Phase Shifters Specific modeling is required in the IDC to identify the phase shifters. There is also a set of data that is required to be entered in the BoF to support the IDC modeling. Pseudo control areas are created on each side of each phase shifter, each with a generator, then one more for the total on each side. The tag is broken up based on this layout. When the correct POR/POD is selected IDC knows to use this modeling. If the tag is not submitted with the specific POR/POD identifying the phase shifter, that transactions will be continue to modeled normally, flowing on the A/C system NOT be modeled in the segments representing the phase shifter. When the phase shifter is not regulating the submittal format on the etag is irrelevant, the same result will occur whether the etag references the phase shifter or not Submittal of etags over Phase Shifters The manner in which a customer submits an etag over an interface that contains phase shifters will determine how the TDF on the transaction is determined in the IDC. To accurately capture the phase shifter path, there should be a specific POR/POD available to indicate that the customer wants to flow energy over the phase shifters. If there are multiple phase shifters on an interface, 2

3 it is not expected that the customer could select which specific phase shifter would be utilized for the flow. For example, if a customer submits an etag over the ONT-DECO path and does not select the specific POR/POD associated with the phase shifter, the tag is assumed to flow over the A/C network and will be modeled as all other etags in the IDC. However, if the customer submits an etag over the path ONT-DECO and does select the specific POR/POD associated with the phase shifter, the IDC would know this tag will flow over the phase shifter and will subsequently break this tag into three segments prior to any internal calculation processing for a TLR. The three segments are: (1) From the Source to the Phase Shifter (2) Across the Phase Shifter (3) From the Phase Shifter to the Sink. If any of the separate segments of the tag are impacted by a TLR, then the entire tag is curtailed accordingly IDC Use of Phase Shifters in Regulate Mode Phase Shifters in the IDC can operate in one of three modes: Regulate, Non-Regulate, and Bypass. The description below defines how the segment of the tag across the phase shifter is modeled in the IDC when the interface is in Regulate Mode. Though the explanation below references the DECO-ONT flowgate, the same principles apply to any fully regulated flowgate or interface. In regulate mode, the IDC models tags that can impact the phase shifter interface in two different ways, depending on how the etags are created by the customer: 1. An etag not using the phase shifter POR/POD that would normally have some distribution across the DECO-ONT flowgate will see the regulating phase shifter as an open circuit and will distribute 100% of the flow across the rest of the network model. For example, because the only other A/C path between MISO and ONT is through NYISO, these tags would appear to flow over the A/C network through the NY flowgates, impacting all flowgates along that path. 2. An Etag using the phase shifter POD/POR will be seen by IDC as flowing over the DECO- ONT flowgate. The percentage of flow that will be directly modeled over the phase shifters is based on the selected Distribution Factor. The Distribution Factor indicates what the percentage of the submitted etag is targeted to flow on each separate phase shifter on the interface. Since the typical use of the phase shifters is as described under Scenario 1, where an interface would be fully regulated, the sum of the distribution factors entered on that interface should be 100%. Under this condition, virtually no distribution from these transactions will be seen on other flowgates, their TDFs become very close to zero. Under this condition these transactions will not be subject to TLR curtailments by the IDC model. 3

4 2.4. IDC Use of Phase Shifters in Non-Regulate Mode In non-regulate mode, the Distribution Factors entered in the Phase Shifter Detail screen do not apply. IDC calculates the TDFs based on the impedance of the current tap position. Note that the impedance is lowest at neutral tap and increases as the taps move up or down away from neutral. When a phase shifter is in non-regulate mode, all transactions are subject to all TLR curtailments. In this case, even if the transaction is identified as flowing over the phase shifter POR/POD path, it is subject to all TLR curtailments. The TDFs will accurately represent the current tap position. Relatively speaking the impedance change from the various tap positions have a very small impact on the distribution calculations. The results in this case, will be very close to those seen prior to the PAR model in IDC IDC Use of Phase Shifters in Bypass Mode Because SDX does not currently send the status of bypass disconnects, it is up to the user to select this status in the IDC from the phase shifter detail display. With bypass selected, the model uses the impedance at the neutral tap setting for the transformer. That means that IDC ignores all of the following: the ISN tap positions, the manual tap positions and the SDX data on the transformer. While the phase shifter is set to bypass mode in the IDC, an SDX branch outage of the phase shifter will not take effect. In this scenario the IDC model will still see the phase shifter as inservice and on bypass. If a user wants an SDX branch outage of the transformer to be reflected in the IDC, the phase shifter should be left in non-regulate mode 4

5 3.0 Entering Phase Shifter Data To get to the Phase Shifter summary screen, where you can display the mode of a phase angle regulator in IDC select, Phase Shifter from the Model menu item Phase Shifter Summary Screen The Phase Shifter button brings up a summary screen that displays the current mode and status of the phase shifters in IDC. The Phase Shifter summary screen displays the current status of the phase shifter data, the source of that data and the resulting impedance. All IDC users can view this page. Field PS Bank Name ICCP Tap Position Reg Status Percent Schedule Impedance A/C Network Description Shows the interface where the phase shifters exist. This field is a hotlink to the Phase Shifter Detail screen for those users who have access to that interface. Every user in the region that 'controls' the phase shifter will have access to that screen. The setup of the IDC model will determine which region has control of the phase shifter. Shows the name of the circuit containing the phase shifter. There will be one row of data for every phase shifter in the interface. If there is one or more A/C lines on that interface, they will not appear in this screen. This is the ISN data point identifier These fields show the current data source and current tap position of the phase shifter These fields show the current operational mode of the phase shifter This is also referred to as the Distribution Factor. For etags submitted over the phase shifter interface, this shows what percentage of those etags will flow over each phase shifter in the interface. Note: It is expected that this total will be 100% for interfaces that are using the phase shifter modeling. Based on the current settings, this shows the resulting current impedance of the phase shifters. This field shows how much of the interface is flowing on the A/C network; how much has not been designated to be under regulation by the assignment in the Percent Schedule column. This value is the difference between 100% and the total assigned in the Percent Schedule column. 5

6 3.2. Phase Shifter Detail Screen From this page in IDC the user has full control over what IDC uses for the phase shifter data in the model. While the options of each selectable field are different, and discussed in future sections, the general functionality of each field is the same: The desired selection is made via the dropdown or data entry field In order to have any change take effect the checkbox beside the data being changed MUST be checked Once the desired data is selected/entered, the Update button must be pushed to make the change to the model. If the user selects the Reset button before the pressing the Update button, the display will revert to the data previously saved in the model. These checkboxes must be checked for any field where data changes are desired. If not checked, the changes will not take effect when user clicks Update 6

7 3.3. Entering Data: Tap Position and Data Source IDC will normally get the phase shifter tap positions from data sent via the ISN. The Tap Position displayed on the screen will be the current tap position if the Data Source is selected to ISN. IDC will also monitor the quality of the data coming in. If the data point for any individual phase shifter fails, the appropriate user will be sent an alarm via the normal IDC alarming mechanism. While there is an ISN failure, the user can choose to manually enter the tap position for any or all of the phase shifters on the interface, see table below. IDC will also send the user an alarm when the ISN data quantity is no longer failed. When the user receives the alarm indicating the ISN data point has returned the user should remove the manual override. Changing Data Source from ISN to Manual Activity Comment 1 Select the tap from the Tap Position drop down box 2 Select Manual from the Data Source drop down box 3 Check the boxes beside each new selection If not checked, the data will not be changed 4 Click the Update button IDC will use these new settings for the next matrix calculations 7

8 3.4. Entering Data: Regulation Status IDC will operate the phase shifters in three selectable modes of operation in the model, shown in the Status field. The status of each phase shifter in the bank must be changed independently. Selecting Phase Shifter Mode Activity Comment 1 Select the desired mode from the New Status drop down box Options are: Regulate, Non- Regulate and Bypass 2 Check the boxes beside each new selection If not checked, the data will not be changed 3 Click the Update button IDC will use these new settings for the next matrix calculations 8

9 3.5. Entering Data: Schedule Distribution Percentage While in REGULATE mode, IDC needs to know what percentage of the Etag schedules designated to flow over the phase shifters should be distributed across each PAR within flowgate in the model. Those values are entered here. Selecting the Schedule Distribution Percentage Activity Comment 1 Select the desired mode from the New Status drop down box Options are: Regulate, Non- Regulate and Bypass 2 Check the boxes beside each new selection If not checked, the data will not be changed 3 Click the Update button IDC will use these new settings for the next matrix calculations Note: The sum of the percentages can be below, above or precisely at 100%. This distribution tells IDC what percentage of the Etag schedule the phase shifters are set to regulate at. If the total of these values is more than 100%, the IDC will actually model the excess flow in the opposite direction of the specified flow. For example, if the Tags were flowing from DECO to IMO and the total was specified at 110%, then the IDC would actually model 10% of the tag flow as flowing from IMO to DECO.. 9

10 4.0 Viewing Phase Shifter Data in the IDC When Phase Shifters are modeled and active in the IDC, there are some screens that will appear slightly different to the user. Whole Transaction List Below is a screen shot of the Whole Transaction List for a specific flowgate showing how a tag that was submitted to flow over a phase shifter will appear to the IDC user (the Tags displayed in red text are those tags that are sinking into the current user's control area). The column Controlled Schedule indicates "YES" when a tag is flowing over a phase shifter that is in Regulate mode. Other than that specific condition, that field will contain a value of "NO". A value of YES in this Controlled Schedule field indicates that this tag is flowing over a phase shifter that is in Regulate mode 10

11 When the user opens the tag detail screen from the Whole Transaction List for a tag that has a Controlled Schedule of "YES", the IDC modeling of that tag is displayed as shown below. In the example below, the tag has been broken into three segments, two showing a specific source-sink and one showing the details of what is flowing over the phase shifters. In this example, the phase shifters are regulating to 60% of the scheduled flow. (why isn't there a 40% in the AC network row??) excellent question. The remaining uncontrolled flow for this tag results in a 14% TDF on the selected flowgate. Because of that 14% TDF on the A/C network, this tag would be eligible to be curtailed if a TLR were called 11

12 5.0 DC Ties in the IDC 5.1. Modeling Requirements for DC Ties The methodology used in the IDC to model transactions that cross Phase Shifters is also utilized to reflect transactions that flow on DC ties such that the TDF on the DC tie is zero. The DC tie could be radial where only one end of tie is located in the Eastern Interconnection or the DC can be located fully within the Eastern Interconnection. Specific modeling is required within the P/SSE model to represent the DC Ties to allow this methodology to be applied. A Change Order is required to establish the initial modeling process for a new DC Tie. Every subsequent P/SSE model build will include the required modifications for all DC ties. For a DC tie that has only one side in the Eastern Interconnection, the P/SSE model is modified to contain a pseudo control area for the end of each DC tie that is not located in the Eastern Interconnection. The location of the source/sink for the DC ties are mapped within the IDC to these pseudo control area based on the data provided on the etag. For a DC tie that is wholly located within the Eastern Interconnection, the P/SSE model is modified to contain two pseudo control areas, one to represent each end of the DC tie Submittal of etags over DC Ties When an etag is submitted over a DC tie where there is defined mapping for that tie the transaction is broken into segments similar to the process described for phase shifters. The TDF for each segments are totalled to provide the overall TDF for that transaction. If a transaction is impacted by a TLR, the user can view the TDF on the individual segments by selecting the tag name on the Congestion Management Report. This can also be viewed using the Whole Transaction List. 12