Electrical System Design and Basic Control with Simulink IEEE student board – IEEE PELS/IAS joint chapter Author: Elisabeth Vandeventer

Outline Introduction to the project Development of a simple wind turbine model Presentation of the load and grid models Interconnection of the network elements Implementation of secondary source and storage Assignment

Introduction to the project Experimental network for isolated village 100 households, cold climate; 𝑃 𝑙𝑜𝑎𝑑 =33.8𝑘𝑊, 𝑃 𝑙𝑜𝑎𝑑 =90.9𝑘𝑊 Windy area, river nearby Your goal: Design a control system to regulate the power flow in the network and make it stand-alone Your power sources: Primary: 60kW wind turbine Secondary: hydropower turbine located on the river Storage: battery bank

Simple wind turbine model 60kW wind turbine Power curve from provider Steady-state values  need to make it dynamic Addition of inertia time constant: 𝐻=2.63× 𝐷 0.12 Final model http://www.icrepq.com/icrepq07/361-gonzalez.pdf

Load model Dynamic three-phase load Input: PQ Connect to the three phase grid

Infinite grid representation Three phase, 230Vrms line-to-line Ideal representation:

Interconnection of the blocks Use of an idealistic converter: use source output power as input and transforms it into 3 phase current waveforms

Power flow Primary source uncontrollable Infinite grid needs to provide power System is not stand-alone! Need addition of: Controllable secondary source: hydropower turbine Electricity storage: battery bank

Hydropower turbine Mathematical model: 𝑃=𝜂𝜌𝑄𝑔ℎ Addition of inertia time constant 𝐻 𝑡𝑢𝑟𝑏𝑖𝑛𝑒 , maximum power output (saturation) and valve control Output power sent to ideal converter for connection to the grid Controlled through the use of the valve

Battery bank Available in SimPowerSystems library Charged/discharged with CCS Monitoring State Of Charge for control Use 𝑃=𝑉×𝐼 to send to converter and connect to the grid

Assignment – goal Your goal: (close to) no exchanged power with the grid 𝑃 𝑠𝑜𝑢𝑟𝑐𝑒𝑠 – 𝑃 𝑙𝑜𝑎𝑑 ± 𝑃 𝑠𝑡𝑜𝑟𝑎𝑔𝑒 ≈ 0 How to achieve that: Resize the secondary source and battery bank Write a clever control scheme that will handle the power flow

Assignment – input and outputs Inputs to the model: Load profile Wind profile Constant water flow Quantities to visualize: Wind power Hydro power Load consumption Battery SOC Power exchange with the grid

Assignment – control signals Wind power  uncontrollable Hydropower turbine Monitor: output power Control with: valve opening Battery: Monitor: state of charge Control with: power to inject/draw Infinite grid: power exchange occurs automatically to ensure power balance (nothing to do)

Assignment – sources parameters Wind turbine: Battery bank Spec sheet: NPS 60-24 Type: lead-acid Inertia time constant: 𝐻=2.63× 𝐷 0.12 𝑉 𝑛𝑜𝑚 =24𝑉 Initial SOC: 50% Hydropower turbine: Min/max SOC: 15-95% 𝜂=0.95 Response time: 1s 𝜌=1000 𝑘𝑔/ 𝑚 3 Discharge currents: [6.5 13 32.5] 𝑔=9.81 𝑚/𝑠 ℎ=20 𝑚 Rated capacity: 16kAh 𝑃 𝑚𝑎𝑥 =30𝑘𝑊 Warning: parameters in red might need to change GOOD LUCK!