DATA AND MODEL REQUIREMENTS FOR GENERATING SYSTEMS OF LESS THAN 30 MW

Transcription

1 DATA AND MODEL REQUIREMENTS FOR GENERATING SYSTEMS OF LESS THAN 30 MW PREPARED BY: Network Models Systems Capability VERSON: Final DATE: 28 June 2013 Australian Energy Market Operator Ltd ABN NEW SOUTH WALES QUEENSLAND SOUTH AUSTRALIA VICTORIA AUSTRALIAN CAPITAL TERRITORY TASMANIA

2 Version Release History Version Date By Approved By Changes 0.1 June 2013 BB MS This document has been created by the Network Models Systems Capability and will be reviewed from time to time. Any queries or suggestions for improvement should be addressed to Babak Badrzadeh Page 2 of 17

3 Important Notice This document details AEMO s preferred approach for meeting the model and data requirements in the National Electricity Rules (Rules) for generating systems with a combined nameplate rating of less than 30 MW. This document is current as at the date of publication, but may have been updated or amended. Please ensure you are using the latest version downloaded from AEMO s website. This Guideline is not legally binding, and does not replace applicable requirements in the National Electricity Rules or relevant AEMO Guidelines. AEMO has made every effort to ensure the quality of the information in this Guideline but cannot guarantee its accuracy or completeness. Accordingly, to the maximum extent permitted by law, AEMO and its officers, employees and consultants involved in the preparation of this document: make no representation or warranty, express or implied, as to the accuracy or completeness of the information in this document; and are not liable (whether by reason of negligence or otherwise) for any statements or representations in this document, or any omissions from it, or for any use or reliance on the information in it Australian Energy Market Operator Limited. The material in this publication may be used in accordance with the copyright permissions on AEMO s website. Page 3 of 17

4 Table of Contents 1. Introduction 5 2. Summary of AEMO s Data and Model Requirements 5 3. Requirements in the Rules 7 4. AEMO s Data and Model Requirements Data Requirements Distribution connected generating systems Transmission connected Generating Systems Model Requirements Other Model Information Tests to Demonstrate Data and Model Accuracy Test requirements for generating systems with combined capacity greater than 15 MW and less than 30 MW Test requirements for generating systems with combined capacity equal or less than 15 MW Other Circumstances 13 Appendix A Relevant requirements in the Rules 14 Page 4 of 17

5 1. Introduction The rules allow some flexibility for data for some generators. This document details AEMO data and models requirements. While these requirements are considered on a case by case basis this document has been prepared to give guidance on what AEMO s likely requirements are. The NSP may have additional requirements above and beyond the data requirements for AEMO. This document details AEMO s model and data requirements for generating units with a nameplate rating of less than 30 MW, and generating systems with a combined nameplate rating of less than 30 MW. This document has been developed for a number of reasons: While the National Electricity Rules (Rules) contemplate lesser requirements for smaller generating systems on certain areas covered by the Rules, the requirements relating to assessment of access standards for connection applications are the same as for larger generating systems. More generating systems are being embedded into distribution networks. In some cases, these generating systems significantly exceed the local load for which the network was designed. Connections to these weaker networks make the need to model this plant more critical. There have been several cases of generating systems connecting into distribution networks close to each other, making the need for modelling more important to assess any potential interactions and the combined effect of these systems on system security. AEMO may vary its requirements on a case-by-case basis. Specifying AEMO s requirements in this document does not diminish either a Network Service Provider s (NSP s) or AEMO s ability to request further information where the Rules permit, or to reduce the requirements as the circumstances permit. In considering any changes to information requirements, AEMO may need to consider any system security impacts while NSPs may need to assess impacts on other network users. Note that the requirements set out in this document are not intended to be applied to generating units that are granted exemption from registration, but the NSP may still require data to be provided in order to ensure there is no adverse impact on other network users. The NSP should be contacted at the earliest opportunity to discuss what data requirements are like to apply in the case of expemtion. 2. Summary of AEMO s data and model requirements Following a review of requirements for new or altered generating systems, AEMO considers the summary of requirements shown in Table 2-1 to be the minimum requirements. The approach adopted treats generating systems of various generation capacities differently, as the capacity reduces, so does the information provision requirement. The requirements for generating systems of 30 MW or more are clear in the Rules, and are also provided in Table 2-1 for information. Page 5 of 17

6 Section 3 of this document describes the specific requirements in the Rules. Section 4 discusses and explains AEMO s requirements. Section 5 lists the special circumstances for which additional information may be required. Table 2-1: AEMO s data and model requirements Requirements Data Sheets - transmission-connected generating system Data Sheets - distribution-connected generating system Notes: 5MW S, D, R1 and R2 [1] Generating System Size > 5 MW & 15 MW S, D, R1 and R2 [1] > 15 MW & < 30 MW S, D, R1 and R2 [1] 30 MW S, D, R1 and R2 S only [7] S and D only [7] S, D and R1 [6] S, D, R1 and R2 Releasable User Guide Required [8] Required Required Required Dynamic Model [2] Generic or Generic or Generic or [3] [8] Detailed Detailed [3] [3] Detailed [4] Detailed Model source code Exempted / Provide if Exempted / Provide if Exempted / Provide if Required available [9] available available Model confirmation tests Self-compliance unless required [5] [8] by NSP Self-compliance unless required by NSP [5] Required [5] Required R2 Tests Required for transmission connected plant [1] [8] only Required for transmission connected plant only [1] Required for transmission connected plant only [1] Required 1. Transmission connected generating systems of less than 30 MW would need to apply for a Variation Request in order to reduce this requirement. S = Standard Planning Data; D = Detailed Planning Data; R = Registered Data (R1 pre-connection, R2 post-connection) 2. To include functional block diagram of the system and encrypted model source code (i.e. PSSE object code). 3. The model can be of a generic type that must fully describe the control systems and plant. For example a participant with a synchronous machine must provide models of the synchronous machine, AVR and PSSif applicable. Other models such as limiters and governor/turbine may also be requested. 4. Any detailed model should be provided according to AEMO s Generating System modelling guideline specifications Additional tests may be requested to confirm performance standard requirements, which may include tests to confirm or calibrate the models. 6. Functional block diagrams provided with the data sheets must be for the model provided for studies (e.g. generic model) and, if different, the actual block diagram for the installed plant. 1 Forms/Generator/~/media/Files/Other/registration/ %20pdf.ashx Page 6 of 17

7 7. Data to be provided with a connection application and to be confirmed at the time of registration. 8. Only required if the plant requires negotiation of generator performance standards. 9. Section 5 of this documents contains further information on special circumstances. 3. Requirements in the Rules The Rules have specific requirements for the provision of mathematical simulation models 2 and design data 3 requirements for generators in respect of a generating system with a combined nameplate rating of 30 MW or more. The Rules are less specific for generating systems with a combined nameplate rating of less than 30 MW. Where the requirement is not specific, the Rules allow reasonable discretion on the part of the NSP or AEMO to require additional information. Generators connecting generating systems of less than 30 MW are generally required to provide a reduced set of planning and registered data. However, data must be supplied if reasonably required by the NSP or AEMO. Despite the Rules not explicitly addressing the requirements for generating systems of less than 30 MW, these models are still required to describe the performance of that plant for assessment of access standards (for new or modified connections), for assessing the implications on registered performance standards for existing generating plant and for operational and planning studies. Appendix A provides a summary of the requirements in the Rules relating to provision of technical design data and model requirements. The Rules make distinctions between the data and model provision requirements for generating plant according to the size of the generating unit, size of the generating system, and where that plant is connected. This is summarised in Table 3-1. In order to be registered in the NEM, a Generator must meet these requirements, including any reasonable discretionary requirements of the NSP or AEMO permissible under the Rules. 2 This refers to the mathematical model provided for a generating unit or generating system that describes the performance of the plant in timeframes suitable for transient stability calculations or for longer term studies where models typically used for transient stability might be used (e.g. mediumterm voltage stability studies). Where models must be provided, these are described in the Generating System Model Guidelines, which are available on AEMO s website. 3 The design data that must be provided is described in the Generating System Design Data Sheets and Generating System Setting Data Sheets, which are available on AEMO s website. Page 7 of 17

8 Table 3-1: Summary of data and model requirements under the Rules REQUIREMENT TRANSMISSION-CONNECTED DISTRIBUTION-CONNECTED Single generating unit >30MW =30MW <30MW >30MW =30MW <30MW Design data [1] YES YES YES YES Reduced [2] Reduced [2] Model block diagram YES YES YES [3] YES YES Not explicit [4] Model source code YES YES Not explicit [4] YES YES Not explicit [4] Model RUG [6] YES YES Not explicit [4] YES YES Not explicit [4] Generating system (2 or more generating units) Design data [1] YES YES YES YES YES [5] Reduced [2] Model block diagram YES YES YES [3] YES YES Not explicit [4] Model source code YES YES Not explicit [4] YES YES Not explicit [4] Model RUG [6] YES YES Not explicit [4] YES YES Not explicit [4] Notes: 1. Design data is provided in the Generating System Design Data Sheets and Generating System Setting Data Sheets (refer clause S5.5.7 of the Rules). 2. The Rules allow a reduced set of data (as an example, Standard Planning Data (or S data) confirmed at time of registration) with some reasonable discretion on the part of the NSP and AEMO to ask for additional information (refer clause S5.5.4 of the Rules). 3. Model block diagrams and parameters are required to be provided under the Data Sheets. 4. There is no explicit requirement under clause S5.2.4 of the Rules. However, additional technical information can be requested by an NSP during the connection enquiry stage. AEMO would be seeking relevant model information, as indicated in this document. 5. A generating system typically comprises one or more generating units. Clause S5.5.6 of the Rules differentiates between a single generating unit equal to or less than 30 MW, and two or more generating units totalling less than 30 MW (but not equal to 30 MW). 6. Releasable User Guide (refer clause S5.2.4(b)(8) of the Rules and glossary definition in Chapter 10 of the Rules). Within the Generating System Design Data Sheets and Generating System Setting Data Sheets (Data Sheets), there are four categories of data (Clause S5.5.2 of the Rules): Standard Planning Data (S) Detailed Planning Data (D) Registered data prior to actual connection and provision of access (R1) Registered data after connection; data derived from on-system testing (R2) Page 8 of 17

9 4. AEMO s data and model requirements 4.1 Data requirements Distribution connected generating systems As the Rules allow lesser requirements for distribution connected generating systems with a combined nameplate rating less than 30 MW, AEMO considers that the extent of the data requirements for the Data Sheets and models should depend on the combined nameplate rating, on a scale proportional to the total capacity, of the generating system connecting to that network. AEMO s typical requirements are: For generating systems of equal to or less than 5 MW, S data is required - to be confirmed to allow registration to be approved 4. For generating systems of more than 5 MW and equal to or less than 15 MW, S and D data are required - to be confirmed to allow registration to be approved. For generating systems of more than 15 MW and less than 30 MW, S, D and R1 data are required to allow registration to be approved. AEMO may revise these requirements according to the circumstances of the particular connection (see Section 5). Generators should seek AEMO s confirmation in each case. As the NSP may have different data requirements the proponent should consult the NSP at the earliest opportunity. In the case of a single generating unit of nameplate capacity of 30 MW connected to a distribution system, for consistency, AEMO will treat this plant in the same way as transmission connected plant. Plant on a distribution system is more likely to affect other network users due to the typically weaker connection point. Therefore, all of the data provision requirements will apply (S, D, R1 and R2). Where R1 data is required for generating systems of under 30 MW, the functional block diagram/s accompanying the Data Sheets are required to be as follows: If a generic model is used, provide both the block diagram for the simulation model, and the actual block diagram/s of the installed plant. Otherwise only the block diagram for the simulation model is required Transmission connected generating systems The Rules do not specifically allow a reduction in the Data Sheet requirements for transmission connected generating systems. However, a generator may request a change to the requirements in the Data Sheets (referred to as a Variation Request). AEMO would consider a Variation Request for a transmission connected generating system equivalent to 4 Except where a generating system is exempted from registration. Page 9 of 17

10 the above requirements for distribution connected generating systems, although this would require the approval of the connecting NSP. It should be noted that AEMO s consideration under these circumstances does not guarantee acceptance and that each Variation Request would be assessed on the circumstances defined in Section Model requirements Model requirements relate to both transmission and distribution connected generating systems. For generating systems with a combined nameplate rating of 30 MW or more, models in accordance with the Generating System Model Guidelines (available on AEMO s website) and additional information associated with the models must be submitted to AEMO and the connecting NSP for connection studies (clause S5.2.4(b) of the Rules). Models are also required for generating systems with a combined nameplate rating of less than 30 MW for a range of purposes, although this is not explicitly mandated by the Rules. It is important to note that some registered performance standards can only be demonstrated through the use of a suitable model; therefore, it is expected that a model will be made available. AEMO requires that models be provided to facilitate AEMO s and the NSP s connection and other studies for the following plants: synchronous generators - models of the synchronous machine, AVR and PSS (when installed) are required. wind and solar farms - the aggregated wind turbine/solar plant model is required, as well as any STATCOM or SVC and fast acting farm controls. other models such as limiters and governor/turbine may also be required, irrespective of type of generation. For generating systems of less than 30 MW, AEMO accepts the use of generic models 5 for connection studies provided that the generator can demonstrate that: such a model can reasonably represent the plant components of the generating system the parameters have been reasonably aligned with the installed plant; and the short-circuit ratio at the point of interconnection is reasonably high (e.g. greater than 3), such that the generic model remains numerically stable. Where commissioning results show that the model and measured results from commissioning tests are substantially outside the tolerances in the Generating System Model Guidelines, and the NSP or AEMO considers that there is either a risk to power system security, the performance may adversely affect network users or the generating system may 5 For example, standard IEEE models for synchronous machines, or IEC/WECC generic wind farm models for wind farms. Page 10 of 17

11 not meet its registered performance standards, then a remedy may be required, including any of the following: additional testing operational limits imposed until the modelling issue can be resolved revised models or parameters (and any required studies) be submitted and accepted (revision may result in submission of a detailed vendor specifc model). Functional block diagrams of these models and the encrypted model source codes (for one of the simulation software products acceptable to AEMO 6 ) must be provided, where this is not already available as a standard feature from the simulation software provider. 4.3 Other model information Other information is normally required to accompany a model, including the Releasable User Guide 7 (RUG) and model source code. The RUG accompanies the model to describe how the model is to be used and includes other information such as transformer modelling information, operational information, information on protection or control systems that are relevant to the assessment of access standards or registered performance standards, and connection point information. This information in a consolidated form is reasonably required to facilitate the connection and other studies and to avoid confusion and potential errors. The Rules do not require unencrypted model source code for generating systems with a combined nameplate rating of less than 30 MW. Where a model is a generic model, it is normally included as a part of the model library typically available through the software supplier. In these circumstances, provision of unencrypted model source code may not be necessary. Where the model is not a generic model, AEMO requires the unencrypted model source code to allow AEMO to update the model to newer versions of the simulation software and to assist studies if a problem is discovered in the software or the performance of the simulated plant. 4.4 Tests to demonstrate data and model accuracy On-site tests are required to confirm the performance of the generating system and to assist in the validation of the model. AEMO may become involved either as the relevant NSP in Victoria, or as system operator in other regions to maintain power system security. Tests to confirm compliance of the generating system with agreed performance standards are carried out during commissioning. AEMO has prepared and published Commissioning 6 Refer Generating System Data and Model Guidelines on AEMO s website. For PSS/E for example, this would be the model object code. 7 Refer glossary definition of Releasable User Guide in Chapter 10 of the Rules. Page 11 of 17

12 Requirements for Generating Systems (available on AEMO s website) to inform this process. Test results from the commissioning tests may also provide, or contribute to, R2 data values. Within three months of the completion of commissioning, applicants are required to submit updated data for any data items requiring R2 data. These data items are identified through the Generating System Design Data Sheets and Generating System Setting Data Sheets. For generating systems of less than 30MW connected to the distribution system, the Rules are not clear in terms of specific R2 test 8 requirements. However, in some cases (refer Table 2-1), reasonable confirmation of model performance is required against actual tests. In this case, model confirmation refers to comparisons of overall (closed loop) model performance rather than deriving each model parameter, as would normally be required for parameters listed as R2. For the model and data requirements, AEMO s requirements and involvement varies according to the size of the plant Test requirements for generating systems with combined capacity greater than 15 MW and less than 30 MW For generating systems with combined capacity greater than 15 MW and less than 30 MW, AEMO expects confirmation of model performance through the tests carried out at commissioning and other documented evidence. The tests at commissioning would typically be limited to voltage step responses over a range of operating conditions. Such confirmation on a single generating unit would be sufficient, in the expectation that the same performance is observed on other units of the same type in the generating system. Confirmation of model performance and other evidence would consist of the following (to be provided to the NSP and AEMO): factory test results for: o electricity generator and energy conversion plant; o control systems, including the energy conversion plants and electricity output control and regulation plants (e.g. exciter, AVR and PSS); o generating unit transformer; and o the generating system transformer (if different from the generating unit transformers). comparisons of simulations for step response tests against the on site step response test results. This would include tests at several load levels and operation across the reative power range, such that: o the model response is within the tolerances specified in the Generating System Model Guidelines; 8 These tests are on-site tests to derive each of the parameters listed as R2 by measurement and analysis. Page 12 of 17

13 o deviations can be reasonably explained through the influences of external impedances or differences in pre-test simulation conditions with actual system conditions; or o typically the accuracy requirements need to be consistent with the Generating System Model Guidelines (subject to NSP agreement, some relaxation of the accuracy requirements could be considered) Test requirements for generating systems with combined capacity equal or less than 15 MW For smaller generating systems (equal to or less than 15 MW), AEMO will be satisfied with self-compliance by the generator. Consultation with the NSP is recommended to ascertain if they specifically require tests to be carried out and confirmation of model performance is to be provided. 5. Other circumstances Section 4 details AEMO s data and model requirements for generating systems of less than 30 MW under normal circumstances. However, more information or tests during commissioning may be required (by AEMO or the connecting NSP) under special circumstances, where, for example: AEMO or the NSP identify the proposed connection and design will have a material impact to the secure operation of the power system. The proposed generating system is connected to a location where its operation may have direct and potentially detrimental influence on other network users. The proposed generating system is connected to a weak network and its dynamic responses and/or the response of the network are sensitive to the control system design. Multiple generating systems below 30 MW are connecting to the same connection point or within short distance from each other, so that the combined effect on the network may be considered to be equivalent to a generating system of total nameplate capacity of 30 MW or higher. Where there is a possibility of the formation of a local electrical island. Page 13 of 17

14 Appendix A Relevant requirements in the Rules These extracts were taken from Version 52 of the National Electricity Rules. A.1 For generating units or generating systems of any size: S5.2.4 Provision of information (a) A Generator or person who is negotiating a connection agreement with a Network Service Provider must promptly on request by AEMO or the Network Service Provider provide all data in relation to that generating system specified in schedule 5.5. S5.5.7 Generating System Design Data Sheet, Generating System Setting Data Sheet and Generating System Model Guidelines (a) NEMMCO must, subject to paragraph (b), develop and publish by 1 March 2008, in accordance with the Rules consultation procedures: (1) a Generating System Design Data Sheet describing, for relevant technologies, the generating system design parameters of generating units and generating systems including plant configurations, impedances, time constants, non-linearities, ratings and capabilities, to be provided under clauses S5.2.4 and this schedule 5.5; (2) a Generating System Setting Data Sheet describing, for relevant generation and control system technologies, the protection system and control system settings of generating units and generating systems including configurations, gains, time constants, delays, deadbands, non-linearities and limits, to be provided under clauses S5.2.4 and this schedule 5.5; and (3) Generating System Model Guidelines describing, for relevant generation and control system technologies, NEMMCO s requirements when developing mathematical models for generating units and generating systems, including the impact of their control systems and protection systems on power system security, and there must be a Generating System Design Data Sheet, Generating System Setting Data Sheet and Generating System Model Guidelines in place at all times after that date. (b) When developing and publishing the Generating System Design Data Sheet, Generating System Setting Data Sheet and Generating System Model Guidelines under paragraph (a), NEMMCO must have regard to the purpose of developing and publishing the sheets and guidelines which is to: (1) allow generating units and generating systems to be mathematically modelled by NEMMCO in load flow and dynamic stability assessments with sufficient accuracy to permit: (i) the power system operating limits for ensuring power system security to be quantified with the lowest practical safety (ii) margins; proposed access standards and performance standards of generating units and generating systems to be assessed; and (iii) settings of control systems and protection systems of generating units, generating systems and networks to be assessed and Page 14 of 17

15 (c) (d) (e) quantified for maximum practical performance of the power system; and (2) identify for each type of data its category in terms of clause S Any person may submit a request (with written reasons) to AEMO to amend the Generating System Design Data Sheet, Generating System Setting Data Sheet or the Generating System Model Guidelines and AEMO must conduct the Rules consultation procedures in relation to the request. AEMO can make amendments requested under paragraph (c) or otherwise to the Generating System Design Data Sheet, Generating System Setting Data Sheet or the Generating System Model Guidelines without conducting the Rules consultation procedures if the amendment is minor or administrative in nature. AEMO may at the conclusion of the Rules consultation procedures under paragraph (c) or otherwise under paragraph (d), amend the relevant data sheet or guidelines (if necessary). A.2 For generating units or generating systems of 30 MW or more: S5.2.4 Provision of information (b) A Generator, or person required under the Rules to register as the Generator in respect of a generating system comprised of generating units with a combined nameplate rating of 30 MW or more, by the earlier of: (1) the day on which an application to connect is made under clause 5.3.4(a); (2) the day on which amendments to performance standards are submitted under rule 4.14(p) or clause 5.3.9(b); (3) three months before commissioning of a generating system or planned alteration to a generating system; or (4) 5 business days before commissioning of a generating system alteration that is repairing plant after a plant failure, if plant performance after the alteration will differ from performance prior to the plant failure, must provide: (5) to AEMO and the relevant Network Service Providers (including the relevant Transmission Network Service Provider in respect of an embedded generating unit) the following information about the control systems of the generating system: (i) (ii) a set of functional block diagrams, including all functions between feedback signals and generating system output; the parameters of each functional block, including all settings, gains, time constants, delays, deadbands and limits; and (iii) the characteristics of non-linear elements, with sufficient detail for AEMO and Network Service Providers to perform load flow and dynamic simulation studies; Page 15 of 17

16 (c) (d) (6) to AEMO, model source code associated with the model in subparagraph (5) in an unencrypted form suitable for at least one of the software simulation products nominated by AEMO and in a form that would allow conversion for use with other software simulation products by AEMO; (7) [Deleted] (8) to AEMO and the relevant Network Service Providers (including the relevant Transmission Network Service Provider in respect of an embedded generating unit) a releasable user guide. The information provided under paragraph (b) must: (1) encompass all control systems that respond to voltage or frequency disturbances on the power system, and which are either integral to the generating units or otherwise part of the generating system, including those applying to reactive power equipment that forms part of the generating system; and (2) conform with the applicable models developed in accordance with the Generating System Model Guidelines, or an alternative model agreed with AEMO to be necessary to adequately represent the generating plant to carry out load flow and dynamic simulations. The Generator must provide to AEMO information that updates the information provided under clause S5.2.4(b) and must provide to the relevant Network Service Providers information that updates the information provided under clause S5.2.4(b)(5): (1) within 3 months after commissioning tests or other tests undertaken in accordance with clause are completed; (2) when the Generator becomes aware that the information is incomplete, inaccurate or out of date; or (3) on request by AEMO or the relevant Network Service Provider, where AEMO or the relevant Network Service Provider considers that the information in incomplete, inaccurate or out of date. A.3 For generating units or generating systems of equal to or smaller than 30 MW: S5.5.4 Data Requirements Schedules to cover the following data areas: (a) (b) (c) schedule Network Plant Technical Data. This comprises fixed electrical parameters. schedule Plant and Apparatus Setting Data. This comprises settings which can be varied by agreement or by direction of the Network Service Provider or AEMO. schedule Load Characteristics. This comprises the estimated design parameters of loads. Page 16 of 17

17 The documents and schedules applicable to each class of Registered Participant are as follows: (a) (b) Generators: the Generating System Model Guidelines, Generating System Design Data Sheet and Generating System Setting Data Sheet; Customers and Network Service Providers: schedules and 5.5.4; and (c) Customers: schedule S5.5.6 Generating units equal to or smaller than 30MW data A Generator that connects a generating unit equal to or smaller than 30 MW or a number of generating units totalling less than 30 MW to a connection point to a distribution network will usually be required to submit less registered system planning data and less registered data than is indicated in the Generating System Model Guidelines, Generating System Design Data Sheet and Generating System Setting Data Sheet. In general these data will be limited to confirmation of the preliminary system planning data, marked (S), but other data must be supplied if reasonably required by the Network Service Provider or AEMO. Codes: S = Standard Planning Data D = Detailed Planning Data R = Registered Data (R1 pre-connection, R2 post-connection) Page 17 of 17