Substation Volt/Var control

develop the best Volt/VAR solution Your team works as a part of the Automation Engineering Services group for Wolfpack Power Services (WPS). Being automation engineers, your group is responsible for developing and deploying both SCADA and automation solutions which includes developing system specifications, implementations of the solution and delivery of working systems to the customer. Recently, Wolfpack Power Services has been awarded a Volt/VAR control project by Carolina Energy (CE), a local utility for a system of the type shown in Fig. 1. CE wants WPS to develop and deliver a substation-based RTU prototype solution based on the Fig. 1 configuration and system data shown in Fig. 2. Carolina Energy is making multiple awards to other automation consulting companies. So your team needs to develop the best Volt/VAR solution in order to be awarded a large follow-up project for the field deployment. Your team is tasked with developing prototype solutions based on the following functional requirements: 1. It is assumed that all logic will reside in a substation-based SEL RTAC located in the substation. 2. The RTAC will communicate with a top of feeder Relay, a substation Regulator Control, a line Capacitor Control and an End-of-Line Voltage Monitor. 3. Communications with these four devices will be via DNP3 protocol. 4. Measurement and Control points available via DNP3 are shown in Fig. 3. 5. There are three controls: Regulator Tap Raise and Lower (range -16 to 16) and Capacitor Switch Position (On or Off). 6. Load varies over a 24 hour time period. The development team will be provided with 3 typical daily load profiles as shown in Fig. 5. 7. A fourth analog output will be for toggling between four different day types. Day type four is is not available to the development team and will only be used for factory acceptance testing. 8. Load is sensitive to voltage, whereas 50% of the load has a constant impedance characteristic, and 50% of the load has a constant power characteristic. 9. The objective of the control is fourfold (i) minimize the daily kW peak (ii) keep all voltages in a 0.95 – 1.05 per unit range (iii) keep power factor at the substation as close to unity as possible using capacitor switching without excessive cycling of capacitor (iv) reduce daily MWh energy consumption. 10. The controller needs to meet the voltage and power factor constraints while minimizing the daily peak and daily energy consumption. Minimizing the daily kW peak takes precedence over daily energy consumption. 11. The prototype should also have an HMI which is accessible via a web browser. The operator should be able to monitor the operation of the Volt/VAR control and see how well the controller is meeting control objectives. The operator should also be able to override the automated Volt/VAR controls.