17/11/21 Situational Awareness UPDEA - Workshop Awareness of the Situation 25,623 Alarms in 8 ours 53 Alarms / min (average) 8% Are consequential Things 1 to keep in mind during a disturbance - Analog data is 19 not Feb reported 26 in - time h with - the 8h state am data 9 Controls are issued but the feedback is very slow 8 Control staff are no longer aware of the situation. 7 Communications protocol (IEC687-5-11) 6 SCADA data base design 5 4 DEVICE AMP Z KV MVA MW TAP PANEL 3 2 1 : :34 :59 1:25 1:5 2:15 2:4 3:5 3:31 3:57 4:23 4:48 5:13 5:38 6:3 6:28 6:53 7:18 7:43 1
17/11/21 State Alarming to Process Alarming 4 kv Arnot 4 kv Simplon 22 kv 132 kv 3 MVA in 3 min. 9 7 Customer Items 27 / 15:3: to keep in mind that will ARNOT cause SIMPL2 a blackout: MVA IG 425 42 ALARM The trip limit is 5% above the 9 degree limit. 27 / 16::22 ARNOT SIMPL2 MVA IG ++ 45 44 ALARM Don t have predictive analysis tools No Rate-of-change alarm processing. No consequential analysis warning No warnings of when it could trip. Alarm Questions Customer ow much knowledge do Control Staff have of the situation? Address of a state change there is no context. No information - only data! Why 2 separate messages? Why not 1 message with all the event Information e.g. 27 / 15:3: ARNOT_SIMPL1 - Trip - ARC - Trip, - Main 1, Zone 1, White phase, - Impedance Earth Fault - 35 km from Arnot - Tripped 3 phase - Locked out Permanent Fault - 32 MVA Loss at 42 kv - DR indicates lightning strike on White phase 2
17/11/21 Electricity Production Namibia Botswana Zimbabwe Windhoek T Transmission Gaboronetransports the electricity to Distribution Pretoria Johannesburg South Africa T Maputo Mbabane Swaziland Generation makes the electricity T P Lesotho Distribution then sells the electricity to the customer N Cape Town Electricity production is a continuous process but we do not P monitor it as such. SCADA Master data base SCADA Substation Device Type Device Real Time alarming is done on this side Point Point Analog Analog Counter Power Application Substn (Network Model) CB Line Bus KV XF Un PAS Prediction tools State Estimation Short-circuit analysis Contingency analysis Voltage VAr dispatch Violation alarming is kept on this side X 3
17/11/21 Monitoring Problems Processes are never static - they are always changing Problems : a 2 Rate-of-change b Load / Truck b d a d t 1 Limit Exceeded a Result : We do not predict the future but we can ands up who recognise this. 4
17/11/21 Adding Situational Awareness Reactive Monitor the Rate-of-Change of the Process Variables. Proactive 5 6 minutes Trip Limit igh ++ igh 1. Temperature 2. Megawatts 3. Megavars 4. Kilo Volts Add Consequential Analysis - (New) Combine PAS tool outputs Add predictive warnings to SCADA 2 4 3 Customer 4 1 1 3 Customer Designing for a Disturbance (1) SCADA Master SCADA Master Philosophy Front Ends use the Containerise bay and station substation state to filter data the alarms Messages are automatically suppressed based on bay state Event data from both ends of a line is combined Bay states Station Bay Venus Bay State Substation State VT 1 2 12 4 32 16 12 Substation Philosophy Bays report their state to the station bay following a change The In station classical state systems is a function each of the point bay is and reported busbar states The station bay decides what is sent to the SCADA Master Update individually messages to are the sent SCADA to all bays master. on the same busbar A Dead Bus automatically sets the alarm suppression flag. 1 message is sent to the control staff for dead busses Include the protection, analog data and what happened 5
17/11/21 Summary Change the: Substation data base to Object Oriented structure Master station data base to support Object Orientation Communications protocol to allow for containerisation Allow Ad hoc messages from RTU Dynamic alarm suppression at Master based on bay state Provide Situations Awareness identification areas using colour Consequential Analysis tool to SCADA tool box Protocol Conversion Dual Front End Computers RTU ost I/O X.21 Designing for a Disturbance (2) EMS Back End Computers SCADA Database SCADA Substation philosophy : Each status and analog values is reported individually to the SCADA master The physical bay structure is modelled in SCADA VT 1 2 12 4 32 16 12 Primary Plant input via the RTU 6
17/11/21 SCADA Bay model Master Station Philosophy Each physical Bay is modelled in SCADA including the substation and region bays. All tele-metered state changes are defined as log only. No messages are sent directly to the control staff from the station. All incoming status and analog value are used to update the bay state only. Level 3 : Network and region Modelling Level 2 : Sub-station Modelling The station state is a function of the bays and busbar states. The bays send messages to update the Station bay state. The station object updates the bay states based on the overall station state. Level 1:Bay Modelling Designing for a Disturbance (3) Alarming The station bay sets flags that decides what alarm data is sent to the control staff by the bays. See example on next slide. The station bay generates and sends messages that are common to the station. For local bay events the bay generates and sends bay related messages For line events the alarm data is combined from both bays to create a single line alarm message A Dead Bus automatically sets the alarm suppression flag. All alarm messages include the protection, analog data and explain what happened 7
17/11/21 Primary versus Consequential 8% of alarms are consequential Battery Charger Battery DC Fail condition Battery Fail Alarm (Primary) Bay DC Fail indication Bay 1 (Consequential) Alarm Log Alarm Log 1314 Bay 1 DC Fail Alarm 13h14 1314 Battery Bay DC 2 DC output Fail Alarm fail alarm 1314 Bay 3 DC Fail Alarm Bay 2 System Activity Log Bay 3 1314 Bay 1 DC Fail Alarm 1314 Bay 2 DC Fail Alarm 1314 Bay 3 DC Fail Alarm Summary Change the: Substation data base to Object Oriented structure Master station data base to support Object Orientation Containerisation is performed at the Master Station Allow Bays to generate alarm messages All alarms are defined as log only at Master Provide Situations Awareness identification areas using colour Consequential Analysis tool to SCADA tool box 8
17/11/21 Situational Awareness Problem identification ighlight problem areas in colour on the display Sequential Analysis Rate of change Contingency Analysis VSAT Indicate the cause and effect and number of possible incidents in a possible event Identify time to Trip Identify consequences of Trfr 2 trip and reasons for tripping. Identify local voltage changes and risks Consequential Analysis Identify Time to Trip (Trfr 4) Identify size of Load loss and number of customers affected Adding Situational Awareness Scenario : Trfr 2 has reported an oil temperature high alarm note red line. Since we measure the actual temperature and can predict, based on the current, when the transformer will trip, i.e. how much time we have before it will trip. Contingency Analysis calculated how much load will be carried by transformer 4 if trfr 2 trips. Contingency Analysis also predicts that trfr4 will also trip on overload. We can also predict how long it will take before trfr 4 trip based on the new load, With VSAT we can estimate the resulting voltage collapse risk if both transformers trip. We can also calculate the total load loss and the number of customers that will be affected. 9
17/11/21 1) ighlight problem area in colour on the display 2) Indicate the cause and effect and number of possible incidents in a possible event 3) ighlight second problem area in a different colour. Include time to trip and consequences. Sequence = 2 of 2 Trip Time = + 2 Interruption = 15 + j55 Reason = Amps Customers = 6 VSAT = No threat Sequence = 1 of 2 Trip Time = + Interruption = 76 + j26 Reason = C Customers = VSAT = No threat Questions 1