ECE 4600 Group Design Project Proposal Group 09 Design and Hardware Implementation of a Supervisory Controller for a Wind Power Turbine Supervisors Annakkage, Udaya D., P.Eng McNeill, Dean, P.Eng Bagen Bagen, Dr. Group Members Alimujiang, Abulizijiang Gill, Ajaypal Przybytkowski, Daniel Uppal, Laraib Date of Submission September 26, 2014
Contents 1 Introduction......................................... 1 2 Project Details....................................... 2 3 Specifications........................................ 2 3.1 Wind Turbine.................................... 2 3.2 Transformers.................................... 3 3.3 Transmission Line................................. 3 3.4 Operation Under Normal Conditions....................... 4 3.5 Operation Under Fault Condition......................... 5 3.6 Development Kit.................................. 6 4 Division of Labour..................................... 7 5 Gantt Chart......................................... 8 6 Budget............................................ 9 7 Conclusion......................................... 9 References 10
1 Introduction The demand for clean energy production is rapidly increasing across the globe due to climate change and environmental concerns. Wind energy is a renewable energy source that has significant environmental benefits, such as zero greenhouse gas emissions and minimal ecological impact. From 2000 to 2012, global wind energy production has grown by an average rate of 24% per year [1]. In a modern wind power plant, a supervisory controller is used to control the operation of multiple wind turbines. The objective of this project is to design a supervisory controller for a single Type-3 2MW rated wind turbine. The supervisory controller will control the power output of the turbine through the regulation of rotor speed and rotor blade pitch angle. Under normal operation conditions, the controller will monitor wind speed, and the turbine will generate power in accordance with the typical power curve of a Type-3 wind turbine. According to the Canadian Grid Code for Wind Development [2], the controller will carry out Low Voltage Ride-Through (LVRT) under fault condition. The supervisory controller will control the turbine of the wind power system designed for this project shown in Figure 1. Fig. 1: Wind Power System Diagram The supervisory controller will be simulated in RSCAD as well as implemented in hardware. The hardware controller will interface with the Real Time Digital Simulator (RTDS) simulating real world conditions, and a comparison of the performance of the simulated controller and the hardware controller will be carried out.
2 Project Details 2 Project Details The project is divided into four main components: literature review, the RSCAD simulation, hardware implementation, and testing. The literature review is a vital component of the project because it will provide the group members with the necessary background knowledge required about the functions of a supervisory controller within a wind power plant. In order to simulate the supervisory controller in RSCAD, the team will partake in multiple RSCAD tutorials. The development kit will be selected during the early stages of the project to allow familiarization with the Integrated Development Environment. The software simulation and hardware implementation of the supervisory controller will be carried out in a parallel manner. The hardware controller will be interfaced with the RSCAD simulation of the wind power system shown in Figure 1 using RTDS. The performance of the both the software and hardware supervisory controllers will be evaluated based on the specifications given in Section 3.4 and 3.5. 3 Specifications The specifications for each part of the wind power system as seen in Figure 1 are outlined in the following sections. This includes the wind turbine, transformers, and the transmission line. The operation of the system under normal conditions and fault condition are also specified, as well as the requirements for choosing a development kit. 3.1 Wind Turbine The turbine used for this project is a Type-3 model most commonly used in modern wind power plants. As per Udaya D. Annakkage s request, the turbine will be rated at 2MW, operating at 60Hz, and must be variable speed and able to be pitch regulated. Having met the requirements, the turbine selected for this project will be modeled after the V110-2.0 MW manufactured by Vestas. A summary of the turbine parameters is provided in the Table 1. - 2 -
3 Specifications Table 1: Wind Turbine Parameters [3] Parameter Value or Range Rated Power 2 MW Blade Length 54 m Rotor Radius 55 m Cut-in Wind Speed 3 m/s Rated Wind Speed 11.5 m/s Cut-out Wind Speed 20 m/s Power Coefficient 0.2-0.45 Air Density 1.225 kg/m3 3.2 Transformers There are two transformers required for the wind turbine system model. The first 3-phase transformer will connected to the Doubly Fed Induction Generator (DFIG) as shown in Figure 1. The transformer will step up the generated voltage from 690V to 33kV. The second 3-phase transformer steps up the 33kV to 230kV, connecting the system to the strong grid through a transmission line [4]. 3.3 Transmission Line The generated voltage from the wind turbine is connected to the strong grid through a transmission line. The parameters for the transmission line used in the RSCAD simulation are seen in Table 2. Due to computational limitations of RSCAD, the transmission line must be greater than 15 kilometers. - 3 -
3 Specifications Table 2: Transmission Line Parameters [4] Parameter Line Resistance Line Inductance Line Capacitance Line Length Value or Range 0.05 Ω /km 1.30 mh/km 0.0089 F/km >15km 3.4 Operation Under Normal Conditions The supervisory controller must control operation of the turbine under normal conditions based on the power curve of the V110-2.0 MW [3] shown in Figure 2. For wind speeds under 3 m/s, the turbine will be stalled. At the cut-in wind speed of 3 m/s up to the rated wind speed of 11.5 m/s, the turbine will operate at a constant tip to speed ratio through the control of rotor speed. From the rated wind speed of 11.5 m/s to the cut-out wind speed of 20 m/s, the pitch angle of the turbine will be controlled to maintain a constant rated power of 2MW. Due to engineering design limits and safety constraints, the turbine will be stalled at wind speeds above 20 m/s. Fig. 2: Power Curve of the V110-2.0 MW Turbine [3] - 4 -
3 Specifications 3.5 Operation Under Fault Condition According to the Canadian Grid Code for Wind Development, the wind turbines must adhere to the LVRT curve as shown in Figure 3 [2]. When a fault occurs, the wind turbine will continue operating for a period of 150ms after which the turbine must be stalled. After a total duration of 3 seconds after a fault has occurred, the system will check for an 85% or greater recovery of voltage. If the voltage has recovered to the 85% or greater level, the turbine will be re-connected to the system. However, should this threshold not be met after the 3 second time interval, the system will remain stalled. In the wind power system illustrated in Figure 1, a 3-phase line to ground fault will be applied on the transmission line after the 33kV/230kV transformer to simulate a worst-case fault scenario. The supervisory controller will control the system to adhere to the LVRT specifications of the Canadian grid code. Fig. 3: Low-Voltage Ride-Through [2] - 5 -
3 Specifications 3.6 Development Kit The specifications for the selection of a development kit are summarized in Table 3. The Arduino Due was selected as the base design product meeting the minimum requirements shown in Table 3. The Arduino Due operates at a clock speed of 84 MHz, has 12 analog inputs and 2 analog outputs at 3.3V [5]. The Digital to Analog Converter (DAC) MAX520BCPE+-ND was selected in order to provide aditional analog outputs. Table 3: Development Kit Specifications Parameter Description Value or Range Clock Speed Number of Analog Inputs Number of Analog Outputs Operating Voltage Analog inputs are not read simultaneously. In order to monitor each input at a minimum rate of 1000 samples/sec, as well as compute and execute commands, a development kit that can operate at 10 MHz or greater was suggested by Dean McNeill. Required signals to be monitored are 3-phase current, 3-phase voltage, torque, and wind speed. Required output signals are rotor reference speed, brakes, pitch angle, and possible turbine speed control. Should the development kit not provide analog output, DACs will be used. The Giga-Transceiver Analogue Output and Input cards connected to RTDS have an analog maximum voltage rating of 10V. 10+ MHz >8 0-4 0-10V - 6 -
4 Division of Labour 4 Division of Labour The parallel nature of software simulation and hardware implementation will allow each team member to gain a better understanding of each component of the project. The simultaneous approach reduces the dependency of implementing the hardware supervisory controller solely upon the successful completion of the software simulation. A summary of the project milestones and tasks is provided in Table 4. Table 4: Milestones, Tasks, and Division of Labour Milestone Tasks Individual in Charge Literature Review RSCAD Simulation Hardware Implementation Wind Power Turbines and Generation Turbine Operation Under Normal Conditions Turbine Operation Under Fault Condition Familiarization With RTDS Tutorial on RSCAD Simulation of System Excluding Supervisory Controller Design Supervisory Controller Design Supervisory Controller For Normal Conditions Design Supervisory Controller For Fault Condition Select Development Kit Learn Integrated Development Environment Program Supervisory Controller For Normal Conditions Program Supervisory Controller For Fault Condition Interface With RTDS Group Group Group Group Group Ajaypal, Laraib Ajaypal, Laraib Ajaypal Laraib Alimujiang, Daniel Alimujiang, Daniel Daniel Alimujiang Alimujiang, Daniel Testing Working Test of RSCAD Simulation Ajaypal, Laraib Working Test of Hardware Implementation Comparison Between RSCAD Simulation And Hardware Alimujiang, Daniel Group - 7 -
5 Gantt Chart 5 Gantt Chart Fig. 4: Project Gantt Chart - 8 -
6 Budget 6 Budget The total expected cost is $359.20 out of the budget of $400 that is allocated for capstone design project. The only cost comes from ordering one Arduino Due and two MAX520BCPE+-ND DACs, both supplied by Digikey. An overhead cost of 20% has been included to cover costs of components supplied by the tech shop. Should the Arduino Due not be suffiecient, $200 has been allocated for the selection of a replacement development kit. Fig. 5: Project budget 7 Conclusion The objective of this project is to design a supervisory controller to control Type-3 2MW rated wind turbine. The supervisory controller will control the turbine operation under normal operation and fault condition. The supervisory controller will be simulated in RSCAD as well as implemented in hardware. The project is expected to fulfill the requirements and be completed as scheduled. - 9 -
REFERENCES References [1] I. E. Agency. (2013) Technology Road Map Wind Energy (2013 Edition). [Online]. Available: http://www.iea.org/publications/freepublications/publication/ technology-roadmap-wind-energy---2013-edition.html [2] G. Hassan. (2005) Canadian Grid Code for Wind Development- Review and Recommendations (2005 Edition). [Online]. Available: http://www.nrcan.gc.ca/energy/publications/ sciences-technology/renewable/smart-grid/6081 [3] Vestas. (2013) 2 MW Platform (2013 Edition). [Online]. Available: http://www.nrcan.gc.ca/ energy/publications/sciences-technology/renewable/smart-grid/6081 [4] D. H. R. Suriyaarachach, Sub-synchronous Interactions in a Wind Integrated Power System, Ph.D. dissertation, University of Manitoba, Winnipeg, MB, 2014. [5] Arduino. (2014) Arduino Due Summary (2014). [Online]. Available: http://arduino.cc/en/ Main/ArduinoBoardDue - 10 -