Orkney Active Network Management Scheme: Enterprise Architect Models

Transcription

1 Scheme: Enterprise Architect Prepared by: SSEPD Approved by: SSEPD Issue Date: 30/07/2012 Review Date: N/A 1 of 36

2 Contents 1 Introduction Purpose Orkney Active Network Management (ANM) Use Case Model Orkney ANM Use Case Model High Level Apply for new Connection Connect to Network Monitor Network & Control Generation Maintain ANM System Orkney ANM Application Use Cases Request Budget Estimate/Feasibility Study Request Formal Quotation Prepare Constraint Analysis Accept Formal Offer Orkney ANM Connection Use Cases Plan Work Procure Hardware Undertake Distribution Work Orkney ANM Monitor and Control Use Cases Assess Network Power Flow Monitor NNFGs Monitor Current and Voltage Control NNFG Output Maintain Set Point Signals Raise Alarm Trip NNFG Turn NNFG On/Off Turn ANM On/Off Orkney ANM Maintenance Use Cases Manage Customer Pay Annual Subscription Configure ANM System Update SCADA Screens Undertake Network Maintenance Upgrade ANM Software Orkney ANM Business Process Model Apply for New Connection Connect to Network Monitor Network & Control Generation Assess Network State and Update NNFG Constraints Maintain ANM System Orkney ANM Class Model Orkney ANM State Machine Diagrams Orkney Generator Control Orkney Zone Boundary Control Orkney RPZ ANM Sequence Diagrams Orkney RPZ ANM Curtailment/Release Cycle Orkney ANM Component Model Orkney ANM Deployment Model of 36

3 1 Introduction The ability of the distribution network in the Orkney Islands to accept new renewable generation connections above 50kW became restricted by the capacity of the twin 33kV submarine cable circuits connecting to the Scottish mainland. At times of minimum demand on Orkney, the rated output of the existing Orkney generators accounted for all available export capacity. Under conventional network planning practice, the connection of further generation on Orkney would have required reinforcement of the submarine cables to the mainland grid by providing a third circuit. Additional generation connection capacity, beyond the firm limit (Firm Generation - FG) has previously been made available under non-firm (Non Firm Generation - NFG) arrangements utilising inter-tripping arrangements to disconnect these generators in the event of loss of either of the 33kV submarine cables from Orkney to the UK mainland if the total Orkney export exceeds the capacity of lowest-rated cable. This method enabled 21MW of additional generation capacity to be realised, but this has also been fully taken up by contracted generators. The development and deployment of an Active Network Management (ANM) scheme by Scottish Hydro Electric Power Distribution plc (SHEPD) working with the University of Strathclyde and Smarter Grid Solutions Ltd (SGS) has delivered an innovative means of facilitating further generator connections without expensive reinforcement of the network. Under this scheme, new generators (New Non Firm Generation NNFG) are instructed by automated controls to limit their power output to avoid breaching constraint limits on the electrical distribution network. The capacity available to these generators is derived from real-time network measurements, and depends on the level of the local electricity demand on Orkney and the output from generation. Existing generators are unaffected by the introduction of the ANM scheme. The Future Networks and Policy Department of Scottish & Southern Energy Power Distribution plc (SSEPD) recognised the potential benefits of introducing business and systems analysis modelling techniques to capture an understanding of the project scope and to clearly communicate business requirements and technical solutions. SSE reviewed the marketplace and selected Enterprise Architect from Sparx Systems to facilitate the creation, storage and dissemination of the models. Enterprise Architect supports Unified Modelling Language 1 (UML) and Business Process Modelling Notation 2 (BPMN) and is widely used in the software development industry. UML is used to specify, visualise, construct and document features of a business system. BPMN diagrams articulate the internal business procedures and provide a step-by-step workflow that can be readily understood and communicated to interested parties. 2 Purpose The purpose of this document is to provide the details of the models that have been prepared for the Orkney ANM solution and were used to support the Britain s First Smart Grid: Sharing the Knowledge event held in London on the 18 th May The aim of the event was to provide an opportunity for participants to learn interactively from the experience of developing the Orkney Active Network Management scheme. The material is intended to provide information on the commercial and technical aspects of setting up and operating an ANM scheme. Further information on Enterprise Architect and tutorials on the models within this document can be found on the Sparx website ( 1 Ref for more information 2 Ref for more information 3 of 36

4 3 Orkney Active Network Management (ANM) Use Case Model 3.1 Orkney ANM Use Case Model High Level Use case diagrams are used to model user/system interactions. They define behaviour, requirements and constraints in the form of scripts or scenarios. Further information can be obtained from the Sparx EA website ( The ANM scheme starts with the Customer requiring a new connection. The Major Connections Contracts Department process this application and ask the Distribution and Generation Network Planning Team to provide costs and SGS to provide estimated levels of power generation constraint. If a connection offer is accepted the Distribution Major Projects Team will contact the Customer and schedule the required distribution works. Once the required works and generators are in place the ANM system will be configured by SGS to include the new generation. Once operational the new generation will be constantly sent messages to control the generation output levels in accordance with rules of the ANM system. The network control engineers receive real time information on the ANM system through the SCADA system. They can override the ANM system if required. The ANM system is supported and maintained by the ANM provider SGS. 4 of 36

5 3.1.1 Apply for new Connection The Major Connections Contracts (MCC) Department of SHEPD manages the contractual arrangements for new connections to the network. New generation connections to the Orkney network above 50kW can only be added as New Non Firm Generation (NNFG). This is because the Firm Generation group (FG) and Non Firm Generation (NFG) group have been fully allocated. Before applying for connection the NNFG Customer must already have planning permission. A nonbinding, constraint analysis report is created and issued as part of a connection offer, which estimates the constraint level that the Customer might experience. For further information about the current connection process please visit Connect to Network Once an offer for connection has been accepted the Customer will be contacted and a project manager will be appointed in SHEPD to coordinate activities within SHEPD and with the Customer. The Customer has a responsibility to comply with the progression clauses of the contract; otherwise the contract can be terminated. All associated distribution and communications works are undertaken to enable the new generation to be connected and integrated into the ANM scheme. It is the responsibility of the Customer to provide the communications link from the NNFG site to the ANM scheme in Kirkwall. Use Case Pre-Condition: Customer has successfully passed through the application process. An application has been received and accepted Monitor Network & Control Generation The Orkney ANM scheme is divided into zones and the boundary of a zone is defined when the total output of the generation within the zone less the minimum electricity demand of the supply customers within the zone is capable of exceeding the rated thermal capacity of the distribution network at that location. The boundaries of each zone are thermal constraint points which are monitored so that the ANM scheme receives real-time measurements of current (and voltage) from these locations. The ANM scheme is not required to know the separate values of demand and supply on the network, but obtains real time measurements of the power flow at these constraints points and monitors the output from the NNFGs. NNFG generators are constrained in accordance with the priority stack which defines the order in which they will be curtailed whenever the level of power flow in a zone breaches a threshold level in that zone or in an associated zone Maintain ANM System The ANM scheme is maintained which includes the addition of further NNFG generation, changes to the supporting software and hardware and any network maintenance. 5 of 36

6 3.2 Orkney ANM Application Use Cases Request Budget Estimate/Feasibility Study The Customer makes a request for a budget estimate or feasibility study. For further information about the current connection process please visit Request Formal Quotation Customers can request a formal quotation for connection to the network providing they have planning consent. As part of the formal quotation process, an estimated constraint analysis report is created by SGS and forms part of the offer. This supersedes any constraint analysis reports that may have been created previously. Use Case Pre-Condition: The Customer must have planning permission before applying for connection Prepare Constraint Analysis An analysis of the present network configuration, typical power flow levels and proposed generator capacity is conducted and the results are summarised into an estimate of the typical level of constraint that a Customer might experience at that location and at that point in time Accept Formal Offer Following application and SHEPD processing, the Customer will be provided with a formal offer for the connection. The Customer must formally accept the offer before any works can go-ahead. Use Case Pre-Condition: The Customer must accept a formal quotation within 30 days. 6 of 36

7 3.3 Orkney ANM Connection Use Cases Plan Work All work orders are added to the planning schedule in the project management system (PROMIS). If any work order does not go ahead it is cancelled. For further information about the current connection process please visit Use Case Pre-Condition: The application must have been accepted before Distribution Major Projects can contact the Customer to arrange planning for connection. Use Case Post-Conditions: Following this planning work, the Customer and Distribution Major Projects will have an arranged date for connection Procure Hardware For the connection of a new NNFG all the required hardware components are procured ready for installation on the network and at the Customer site Undertake Distribution Work A project manager will coordinate activities between the various SHEPD departments and the Customer and ensure progress in accordance with the contract. Once the Customer and SHEPD installations are complete the system can be jointed, tested and commissioned for 7 of 36

8 operational use. This includes physical connection, commissioning and integration into the SHEPD SCADA system. Use Case Pre-Condition: This work is scheduled in the PROMIS system by Distribution Major Projects in an initial planning session with the Customer, following acceptance of an application. 8 of 36

9 3.4 Orkney ANM Monitor and Control Use Cases Assess Network Power Flow The ANM system continuously reads the latest information on the network power flow at the monitoring points and determines the correct set point (maximum permitted output level) for each NNFG associated with that zone. Various 'alarms' (information messages) are raised and sent to the SCADA System for the attention of the network control engineer Monitor NNFGs The ANM scheme monitors the status of all NNFGs. If a communication failure from the NNFG is detected, the NNFG reverts itself to a predetermined 'out of service' set point. 9 of 36

10 3.4.3 Monitor Current and Voltage The ANM system monitors current and voltage levels at the monitoring points. Each monitoring point has a number of thresholds designed to ensure the safety of the network. If the communications is lost to the measurement point, the ANM scheme has no information about the power flow in that zone. Therefore, all NNFGs in the zone and associated zones must be instructed to run at their 'out of service' set point Control NNFG Output Monitoring point information is assessed against its threshold values and the generation levels (set point) for all associated NNFGs are calculated and continuously sent to each NNFG. Each NNFG can have different rates at which their generation levels can be increased or decreased and over different time intervals. Various 'alarms' (information messages) are raised and sent to the SCADA system for the attention of the network control engineer Maintain Set Point Signals The ANM system constantly sends set points to all NNFG. The set point consists of a numerical value, measured in pu (per unit). For example, a set point of 0.8 pu instructs an NNFG to limit its output to 80% of its maximum. Each installation can have different set points Raise Alarm Various 'alarms' (information messages) are raised and sent to the SCADA system for the attention of the network control engineer. The following situations are flagged as alarms and action may be required: 1. Generation not responding 2. Generation trim in progress 3. Generation forced trim 4. System emergency Overload Trip 5. DAR in progress 6. Generation holds off 7. Communications fail 8. PLC fault 9. Stabilised (Ready for set point) Trip NNFG A trip instruction is used to ensure network safety and stops a NNFG generating power onto the local distribution network. Any loss of communications between the ANM system and the NNFG is detected by the ANM equipment at the NNFG site and it reduces the output of the NNFG to a pre-defined 'out of service' level. If the power flows on the network rise at a level where it cannot respond adequately by issuing reduced set points then the NNFG in that zone or all associated zones will be tripped. Furthermore, if an NNFG fails to reduce output to its set point level within a predefined time the ANM system will issue a trip instruction to the NNFG Turn NNFG On/Off The DNO have a facility to turn-on or off an NNFG from the SCADA system. This may be required for emergency or network maintenance purposes. When turning off an NNFG in this manner, the circuit breaker at the substation is opened and the NNFG is no longer connected to the network. 10 of 36

11 3.4.9 Turn ANM On/Off The DNO have a facility to turn the whole ANM system on or off from the SCADA system. 11 of 36

12 3.5 Orkney ANM Maintenance Use Cases Manage Customer The Major Connections Contracts department will inform the Customer of any planned, unplanned or emergency interruptions to their service. They will also request the annual subscription Pay Annual Subscription The NNFG Customers are required to pay an annual subscription fee. This is paid at the start of the first year of commissioning and annually thereafter Configure ANM System The Orkney ANM scheme will facilitate the addition of NNFGs. The Orkney Isles power network is divided into zones defined by the constraint points. As new generation sources are connected to the Orkney power network, new constraint points (new zones) may emerge in places where there were no previous issues. 12 of 36

13 3.5.4 Update SCADA Screens The interface to the SCADA system will be modified when required Undertake Network Maintenance There will be periods when the electricity distribution network will undergo repair and maintenance works. This could be for emergency, planned or unplanned purposes. Planned network maintenance requires 5 days notice Upgrade ANM Software The software components may require changing or upgrading; therefore there will need to be a change configuration and management process system to enable component and software upgrades. 13 of 36

14 4 Orkney ANM Business Process Model The Customer applies for a new connection and following receipt of an offer can decide to continue and request the connection or stop. Once connected through the NNFG process the Customer will be monitored and their generation will be controlled. The Customer may be further impacted by the addition of new NNFG, network maintenance and maintenance of the ANM system. 4.1 Apply for New Connection Apply for New Connection New generation connections to the Orkney network above 50kW can only be added as New Non Firm Generation (NNFG). This is because the Firm Generation group (FG) and Non Firm Generation (NFG) group have been fully allocated. As new generation Customers are connected as NNFG, they can only connect following their agreement with the ANM contract and constraint policy (Principles of Access (PoA)). 14 of 36

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16 The above diagram broadly describes the business process for New Non Firm Generation (NNFG) connections to the Orkney network. For further information about the current connection process please visit Connect to Network Connect to Network Connecting an NNFG to the network involves distribution works, communications, electrical protection equipment, commissioning and safety sign off. 16 of 36

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18 The above diagram broadly describes the business process for New Non Firm Generation (NNFG) connections to the Orkney network. For further information about the current connection process please visit Monitor Network & Control Generation Monitor Network & Control Generation The monitoring point data is constantly assessed to determine NNFG output in accordance with the operation of the ANM scheme. The Network Management Centre of SHEPD is responsible for network safety and any faults in the ANM system will be investigated and resolved. 18 of 36

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20 Read Measurement Point Data The ANM system polls the monitoring points at regular pre-defined intervals. Store Measurement Point Data The ANM system stores the data received from the monitoring points. This data is used by the ANM control algorithms to determine the appropriate control of the generation output levels (set points) of the associated generators. If there is a communications failure or the data is not within reasonable bounds to be relied upon then this will trigger a safety response and the associated NNFG will be tripped. Read NNFG Generation Data The ANM system polls the NNFG at regular pre-defined intervals. Store NNFG Generation Data The ANM system stores the data received from the NNFG. Perform Controlled Ramp Down When the ANM scheme instructs an NNFG to trip, the NNFG undergoes an immediate controlled ramp down and stops the export of power onto the network. Restrict Output as per Set Point The ANM scheme maintains a current set point level for each NNFG which is conveyed as an analogue signal between 0 and 20 ma. The set point consists of a numerical value, measured in pu (per unit). For example, a set point of 0.8 pu instructs an NNFG to limit its output to 80% of its maximum. Each installation can have different set points. When reducing the output from an NNFG, the set point is calculated and reduced to the precise level required. Store ANM Data Data from the ANM system is sent to the SCADA system and subsequently to reporting data repository, PI North. This data is subsequently used in analyse to support reporting requirements and governance to ensure the NNFG operators are operating within the terms of their contractual agreements and to ensure the ANM system is operating appropriately. Inform DNO Shift Leader of Alarm Signals are sent to the SCADA system as follows: 1. Generation not responding 2. Generation trim in progress 3. Generation forced trim 4. System emergency Overload Trip 5. DAR in progress 6. Generation holds off 7. Communications fail 8. PLC fault 9. Stabilised (Ready for set point) These may require operator attention. 20 of 36

21 Process Alarm Appropriate action will be undertaken in response to the alarms raised by the ANM system Assess Network State and Update NNFG Constraints Assess Network State and Update NNFG Constraints The ANM scheme requires active data from the monitoring points. These points are organised in zones according to 'pinch' points on the network. The ANM scheme will have a configurable set of threshold levels for each zone and uses the power flow data to actively control the NNFG units as and when the power flow breaches these threshold levels. The priority stack defines the order in which the NNFG will have their generation capacity constrained (trimmed). The thresholds at the network monitoring points are constrained (trim signal), sequentially tripped (turned-off one by one in a zone) and globally tripped (all NNFG in the zone turned-off). When power levels breach the trim threshold the lowest NNFG in the priority stack is constrained first. If power levels at the monitoring points rise too rapidly then the NNFG will be sequentially or globally tripped to ensure network safety. Read Monitoring Point data Real time data from the monitoring points is accessed. If no data is available then this will trigger an error. The state of the network cannot be confirmed and all NNFG in that zone will be tripped; this will be a Global Trip in that zone and associated zones. Assess Monitoring Point data against Threshold Reference data for the monitoring point is accessed and whether the real time data has breached a threshold. An assessment will be made as to the scale of the breach. If the lower threshold has been met then any existing constraint will be lifted. There will be either a breach of an upper threshold, lower threshold, no breach, or no current data. Identify NNFG & Power level instructions This will identify all the associated NNFG in the affected zones and their order in the priority stack. It will then send 21 of 36

22 a message to all the NNFG. If it is a breach of a 'trim' threshold then there will need to be a calculation of the required power outputs for the associated NNFG. Calculate Power level In the case of a breach of a trim threshold the NNFG will be constrained to meet the safe levels of the network and in accordance with their respective position on the priority stack. Issue Trim instruction Constraint instructions are sent according to priority stack. This will be between 0 and 1. Issue Sequential Trip instruction Where power levels are rising too rapidly to allow constraints to be issued and actioned then the NNFG will be sequentially tripped in that zone in accordance with priority stack (LIFO) position. Issue Global Trip instruction If power levels are rising too rapidly to allow constraints or sequential trips to be actioned then a global trip will be issued that will immediately constrain all NNFG to ensure network safety. Issue Reset instruction Following constraint or trip instructions the affected NNFG in that zone will be unconstrained once the network safety levels have been restored. 4.4 Maintain ANM System Maintain ANM System Maintenance of the ANM system involves updating the software configuration of the ANM system, upgrading the software version, and planning and undertaking network maintenance that impacts the ANM system. 22 of 36

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24 Request Subscription Customers will be contacted annually for their subscription payments. Subscriptions are collected on the first and subsequent anniversaries of the connection date. Make Payment The NNFG Customer will make payment in accordance with the terms and conditions of the contractual agreement. Process Payment The payment will be received and cleared in accordance with internal processes and procedures. Undertake Network Maintenance There will be periods when the electricity distribution network will undergo maintenance. This could be for emergency, planned or unplanned purposes. Planned network maintenance requires a notice period. Contact Customer The Major Connections Contracts department will contact the Customer in the event of any planned or unplanned maintenance work that affects their installation. A notice period is required for any planned maintenance work. Emergency work requires no notice period. SHEPD will endeavour to minimise the impact on Customers as much as possible and give as much notice as practical. When a new NNFG is being added to the scheme then the existing NNFG will be put into an 'out of service' state temporarily to enable them to be added. Analyse Issue There will be a change release process that will manage requests for change (RFC) to the system. In the case of emergency maintenance a temporary solution may be put in place to allow a longer term solution to be applied at a later date. Issues and RFCs will be prioritised and will require some initial analysis to identify their respective impact and importance. Request System Access There will be no direct access to the ANM system for the 3rd party supplier (SGS). This must be pre-arranged and agreed with SHEPD. Process System Access Request A request for access to the ANM system is received from the 3rd party supplier (SGS) and processed in accordance with internal procedures and security protocols. Undertake Maintenance/Changes The 3rd party supplier (SGS) will undertake the required changes in an appropriate manner in accordance with the change release process. Remove System Access Once the changes have been successfully implemented then system access to the 3rd party supplier will be removed in accordance with internal procedures and security protocols. Document & Request Changes Changes to the network may result in changes to the SCADA system, in which case a switching schedule will be 24 of 36

25 required. Undertake SCADA Changes Changes will be made in accordance with internal procedures and documentation. Decommission Unit In the event that a NNFG is decommissioned then it will be removed from the ANM scheme and the system will continue to operate in accordance with the rules and principles of access (PoA) for the remaining NNFG. Test, Commission and Deploy Changes System changes are tested and applied to the production environment in accordance with internal change release process. 25 of 36

26 5 Orkney ANM Class Model Class or Structural diagrams define the basic building blocks of a model: the types, classes and general materials used to construct a full model. Further information can be obtained from the Sparx EA website Generator Configuration is part of a Generator that allows it to operate within the ANM system. A Generator is associated to one to twenty Measurement Points by a Zone Boundary Link. A Generator and Measurement Point has one or many Generator Releases. A Measurement Point Status, Threshold Persistence, Post Action Response and Measurement Point Configuration are part of a Measurement Point. Generator The class represents data associated with the real time operation of NNFGs. It includes status data and the position of the NNFG in the priority stack. Generator Configuration The class acts as a container for configuration data associated with a Generator. 26 of 36

27 Generator Release The class acts as a container for data relating to the release of a curtailed generator. Measurement Point The class represents parameters related to the real time operation of a Measurement Point. Measurement Point Configuration The class represents the configuration data relating to a Measurement Point. Measurement Point Status The class acts as a container for the data related the status of a measurement point. Post Action Response The class represents configuration data associated with the response of the ANM scheme after action to mitigate conditions at the Measurement Point. Threshold Persistence The class acts as a container for threshold configuration data for a Measurement Point. Zone Boundary Link The class acts as a container for the position in the Priority Stack for a given generator with respect to a given zone. 27 of 36

28 6 Orkney ANM State Machine Diagrams State Machine diagrams are essential to understanding the instant to instant condition, or "run state" of a model when it executes. Further information can be obtained from the Sparx EA website The Generator Control undergoes the following states. At the start the Generator is out of service and can go to initialising then idling and connecting to the network. Once stabilised the Generator will start generating. It will receive output control levels and can be constrained (Unloading). The Generator can have the circuit breaker tripped whilst connecting or during constraint. Once the circuit breaker is tripped it can have the circuit breaker reclosed to connect to the network again. The Generator can also be put into and out of service state during initialising, idling, constrained or unconstrained generation e.g. communications failure at the site. 6.1 Orkney Generator Control 28 of 36

29 CIRCUIT BREAKER RECLOSING This state represents the reclosing of the metering circuit breaker after a trip due during Connecting or Unloading. GENERATING This state represents the NNFG being normal generating mode of operation. GOING OUT OF SERVICE This state represents the NNFG going Out of Service. INITIALISING This state represents the initialisation of the NNFG controller. OUT OF SERVICE This state represents the NNFG being Out of Service. STABILISING This is an intermediate state between connecting and generating. The NNFG controller remains in this state until the stabilising timer has expired. TRIPPING CIRCUIT BREAKER This state represents the tripping of the local metering breaker due to the generator output being above 2% whilst in the Connecting state or the Unloading state after the unloading timer has expired. UNLOADING The Unloading state represents the NNFG reducing its output to a predefined level. Final Final State Initial Initial State 29 of 36

30 6.2 Orkney Zone Boundary Control The Zone Boundary Control (Monitoring Points) undergoes the following states. At the start it is initialised and at a normal state. It will go into a trim state if the power flow is greater than the trim threshold. If the power flow is then less than the reset threshold it will move to reset and then back to normal. It can also move from a trim state to a sequential trip state if the power flow is greater than the sequential trip threshold; or a global trip state if the power flow is greater than the global trip threshold. It can then be reset and back to normal from both states if the power flow is less than the reset threshold. It can also move straight to sequential trip or global trip from normal if the power levels are greater than the respective thresholds. Global Trip This state represents the highest severity action in the ANM Scheme's escalating actions. All participating generators in the zone are immediately tripped. 30 of 36

31 Normal This state represents normal operating conditions. Flows at the measurement points are below the "Trim", "Sequential Trip" and "Global Trip" limits. All generation participating in the scheme is not curtailed. Reset This state represents the release of the curtailment for all curtailed/tripped generators within the zone after the zone export has dropped below the reset limit. Sequential Trip The Sequential Trip state represents the scheme entering the second highest set of actions in the ANM Scheme's set of escalating actions. Zone generation is tripped based on the priority stack (LIFO) sequence. Trim This state represents the first action in a set of potentially escalating actions. In this state the ANM scheme curtails generators in the zone based on the priority stack and priority stack (LIFO) principles of access after export from the zone has breached the "Trim" limit. 31 of 36

32 7 Orkney RPZ ANM Sequence Diagrams Sequence diagrams are closely related to communication diagrams and show the sequence of messages passed between objects using a vertical timeline. Further information can be obtained from the Sparx EA website Orkney RPZ ANM Curtailment/Release Cycle This Sequence Diagram details the interactions between scheme components for a normal curtailment/release cycle. 32 of 36

33 8 Orkney ANM Component Model Component diagrams are used to model higher level or more complex structures, usually built up from one or more classes, and providing a well defined interface. Further information can be obtained from the Sparx EA website The ANM system comprises of SG Core and a Communications Hub that receives signals from Measuring Devices and the NNFG controller. A Programmable Logic Controller is a type of NNFG controller. The ANM system sends alarms to the SCADA system in Perth; PI North records the history of the network status. The Measuring Device is associated with a substation where an RTU is installed that sends signals to FEP in Aberdeen and onto the SCADA system in Perth. 33 of 36

34 Measurement Device Network Measurement Units (NMUs) located at critical measurement points on the Orkney network providing power flow information. NNFG Controller PLC units located at each NNFG site. The NNFG PLC receives the signals from the ANM NNFG control system located at Kirkwall and monitors the response of the renewable generator via the generator RTU. SG Core SG Core is the real-time power flow management application and contains the algorithms which are run by this PLC (or server) unit to manage devices in the ANM Scheme. Comms Hub Comms Hub acts as the field data aggregator, protocol converter and gateway for subscribing systems and subsystems. The Hub provides the interface to and from the ANM system and enables the integration with the ANM controlled devices and the SHEPD, SCADA system. FEP FEP connects an outstation piece of equipment such as a RTU unit to the centralised SCADA components. FEP typically runs on Windows and runs OPC server. The FEP time stamps each piece of data when it arrives at the FEP. PI North PI North is a data historian system that stores SCADA transactions and monitoring data for the northern distribution and transmission networks ENMAC North ENMAC is a Supervisory Control and Data Acquisition (SCADA) system manufactured by General Electric (GE). ENMAC North is the deployment of the system used to support the NMC in Perth to manage and monitor the SHEPD distribution networks in the North of Scotland. 34 of 36

35 9 Orkney ANM Deployment Model Deployment diagrams show the physical disposition of significant artifacts within a real-world setting. Further information can be obtained from the Sparx EA website 35 of 36

36 CB Control Circuit Breaker Control. Data Mapping Data Mapping between CommsHub and Generator Controller HMI Control Control for the HMI on site. In and Out of Service In and Out of Service control logic. NNFG Control NNFG control logic, as described in the Generator Control state machine. NNFG Watchdog Timer Watchdog timer for monitoring the health of NNFG controllers. CommsHub Watchdog Monitors the CommsHub Watchdog timer to monitor health of communications with CommsHub. Data Mapping Data mapping between CommsHub and Measurement Point. Measurement Point Scaling Scales and processes Measurement Point data. Measurement Point Watchdog Timer Measurement Point Watchdog timer. This is used to check the health of communications between the Measurement Point and CommsHub. 36 of 36