The Chorus Line Reliable Wind Power Control The Chorus Line, managed - - PDF document

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The Chorus Line

Reliable Wind Power Control

The Chorus Line, managed by its ChorusDIRECTOR application software, puts your wind turbines in perfect tune.

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Quest – Introduction

Quest AB – Your Partner Since the start in 1983, Quest has built up a wealth of practical experience in the field of wind power control. This ever-growing experience is used to the benefit of the wind power industry, thus making Quest an ideal partner for development of control technology. Strategy for Success In order to be successful we follow certain key strategies:  Close partnership with windmill manufacturers  Use of industrial standard products  Open software  Modular system  Cost-effective development

Per Stjerneman, Managing Director

Co-development with the Manufacturers The Chorus system is developed in close association with our partners, the windmill

• manufacturers. Our partners’ demands have

formed a controller well suited for modern wind turbines. Use of Industrial Standard Products Our customers’ requirements that the system should employ standard products, resulted in our choice to use standardised industrial bus systems (including Ethernet and CAN), wireless local communication (Bluetooth) and cost-effective man-machine interface (PDA’s). Open Software Functionality Quest has drawn on many years of experience when designing the control software. This know- how is now available to our partners through the

• pen software.

This means that our partners have access to the wind turbine functionality and to various toolboxes

• included. Hence, our customers have the freedom

to create their own specific software solutions and keep them confidential. Modular System It is essential that the development time for partner projects is kept as short as possible. In

• rder to achieve this, the control system’s

hardware and software have been made highly

• modular. This makes future development or

modifications fast, efficient and secure. Cost-Effective Quest has been working in the field of control systems for many years. This accumulated know- how is a key ingredient when developing cost effective solutions for the wind power industry.

Quest – Your development partner!

Göteborg, September 2006 Per Stjerneman Quest Energy Control AB SE-421 66 V.Frölunda, Sweden Tel: +46 31 510010 E-mail: information@questab.com Web: www.questab.com

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Product Family & Central Controller

The Chorus Line – Quest’s Product Family Our family of control system products is called “The Chorus Line”. The family includes the following hardware:  ChorusCPU Central controller  ChorusTRAFO Voltage transformer  ChorusIGNIT Thyristor driver … and the associated software:  ChorusOS Operating system  ChorusDIRECTOR Application software The Chorus Line is designed in such a compact way that these core products, together with a few complementary standard products, form the entire control system that your wind turbines need. ChorusCPU Highlights  High accuracy in measurements  Proven high reliability  I/O via standard industrial bus systems  Easy and quick configuration  Cost effective product Communication The Chorus system features three high speed buses: The Ethernet and two CAN buses. The first CAN-bus is normally used to communicate with the distributed standard industrial I/O modules around the wind turbine, while the second one can be used to communicate with e.g. inverters, a vibration monitoring system or the generator. Additionally, there are two RS-232 ports and two RS-485 ports for e.g. user interface. Software Download The product software may easily be updated via a download procedure. Security Loop In order to achieve a high security in a wind power plant consisting of several different intelligent systems, Chorus includes a specific security feature monitoring an external loop (with e.g. stop buttons). It also offers two security outputs that can block external equipment in case of an

• emergency. Moreover, it is self supervising.

Configuration Inputs/Outputs On- board Max. extension

Digital IN 24 512 Digital OUT 16 512 Analog IN 9 64 PWM OUT 6 64

Communication Number Speed

Ethernet T-base 1 10/100 Mbit/s RS-232 2 115.2 kbit/s RS-485 2 115.2 kbit/s CAN-bus 2 500 kbit/s

General Data Description Data Remarks

Power requirements 24V DC, 3A 18 – 32V Processor type 50 MIPS RISC Motorola MPC 555 Flash memory 8 MB EEPROM 8 KB RAM 2 MB

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Hardware Modules

Chorus Voltage Transformer The voltage and current measurements are used to calculate energy production, blind power and to synchronise the connection to the grid. Quest’s strategy is to separate all grid voltage devices from the controller and to use a standard properly scaled voltage input

• signal. Chorus uses external

voltage trafos for the nominal grid voltage 690/400/230V and to obtain 110V signals from high voltage equipment.

ChorusTRAFO

Description Data

Name ChorusTRAFO Type Single phase type Max Voltage 690V Accuracy 0.3 % Output 0 – 10V

Industrial Standard Modules When expanding the standard Chorus configuration, it is easy to plug in standardised industrial I/O modules from different vendors which all connect to the CAN-bus. The amount of cabling is greatly reduced by distributing the I/O units around the mill.

A bus terminal and some I/O modules

Thyristor Driver Module Thyristors are controlled by the external driver module named ChorusIGNIT. It is typically installed close to the thyristors and communicates with the ChorusCPU module through a bus cable.

ChorusIGNIT

Description Data

Name ChorusIGNIT Thyristor outputs 6 Output voltage, max 690V Output current, max 1A Over-current protection Yes Digital inputs 6

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User Interface

Handheld User Interface + Bluetooth Chorus employs standardised hardware products also for the user interface, for example a small handheld PDA. This terminal connects to the control system via Bluetooth wireless communication The customer benefits are obvious:  Service personnel keep and manage their individual terminal.  The personnel may for example sit in a car

• utside the mill monitoring the operation or

updating parameters.  When working in e.g. the nacelle he may

• perate the plant remotely. Hence, there is no

need for a second person assisting at the central control system downstairs.  The total investment cost is reduced since there is only need for a couple of handheld terminals in an entire wind park consisting of several hundred machines. Fixed Graphical Terminal The Chorus user interface may also include a fixed graphic terminal with touch screen used for demonstrations or when needed in the wind turbine. Central Monitoring System Since the protocol and the software are open the manufacturer can incorporate the mills in the end- customer’s central monitoring system.

User interface through a handheld PDA

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Software

ChorusOS – The Real-Time Operating System This is the software platform on which the application is based. It’s a true real time system designed for the very fast processes involved in electrical energy systems. The OS provides a large number of dedicated resources for application programmers. ChorusDIRECTOR – Application Software  Open source code  Object oriented and written in C++  Facilitates communication within wind farms  Ability to communicate and use standardised industrial bus systems  Easy and quick expansion Open Source Code for Applications Occasionally, the extensive set of parameters in the application is not sufficient to fine-tune the

• peration. Therefore all major applications of the

wind turbine are fully open to our partners. This means that the partner himself can add, change

• r remove functions in the system. Using

predefined functions from the toolbox it is easy to make additions and adaptations. Thus, the partner has full control of the system and its future development (and it will remain confidential).

Programming in perfect control

Programming Model The software is divided into objects according to their functionality. Data exchange between objects is mainly performed via a database. Debugging In case of a programmer’s mistake, extensive tools are available to track the direct source of the problem. Key Services and Utilities  Tools for adding and manipulating database records  Classes for handling field bus I/O devices from a range of manufacturers  Tools to define I/O, irrespective of whether on the CPU unit or on a field bus I/O module  Tasks may be cyclically initiated with 1, 10, 100 or 1000 ms interval  Measurement of true RMS for six voltages and three currents, with down to 10 ms averages  Handling of communication ports  Handling of cyclic values (like wind directions)  Filters for analogue and digital measurements  Timers  Data logging  Graphical interface toolbox Handling of System Faults A special utility is devoted to the handling of any faults that may occur in the controlled process. The utility defines faults with reactions, delays, reset authorisation and location, as well as whether resets should be done. The utility may also obtain status for each fault and for each reaction or set of reactions. As an example: If a message “HydraulicFault” is signalled, all objects can easily retrieve that

• information. The object handling the hydraulic

pump can stop the pump and, moreover, the yawing stops if the yaw brake is hydraulic, etc.

• Mom. power < limit) ||

• Mom. power > limit ||

• Mom. power < bypass limit) ||

Example of state machine diagram

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Software Example

In order to make company specific algorithms or adjustments the wind turbine manufacturer may access the application parts of the Chorus source code, compile and link his own software and, thus, add new functionality. The source code for a simple functional object may look like this : Header file:

//**************************************************************************** //* //* File name: GenHeater.h //* //* Short description: Handles generator heater output //* //* Source code files: GenHeater.cpp //* //**************************************************************************** // $History: GenHeater.h $ // //***************** Version 1 ***************** //User: Hrm Date: 05-04-11 Time: 14:52 //Created in $/ChorusCPU/Software/Source // #ifndef GENHEATER_H #define GENHEATER_H //---------------------------------------------------------------------------- // Include files //---------------------------------------------------------------------------- #include "../GlobalDefs.h" #include "../shell/SysBase/SystemObject.h" //---------------------------------------------------------------------------- // DEFINES //---------------------------------------------------------------------------- //---------------------------------------------------------------------------- // TYPES //---------------------------------------------------------------------------- //---------------------------------------------------------------------------- // CLASSES //---------------------------------------------------------------------------- class CGenHeater: public CSystemObject { public: CGenHeater(); // Constructor int TimerCall(int LoopId); // Called in fixed intervals by OS protected: private: THandle HOutGenHeat, HGenStatus; // Database handles }; extern CGenHeater GenHeater; #endif GENHEATER_H //---------------------------------------------------------------------------- // EOF

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Software Example

Source file:

//**************************************************************************** //* //* File name: GenHeater.cpp //* //* Short description: Handles generator heater output //* //**************************************************************************** // $History: GenHeater.h $ // //***************** Version 1 ***************** //User: Hrm Date: 05-04-11 Time: 14:52 //Created in $/ChorusCPU/Software/Source // //---------------------------------------------------------------------------- // Include files //---------------------------------------------------------------------------- #include "GenHeater.h" #include "../Shell/System/LoopMan.h" #include "../Shell/Tables/FaultTable.h" #include "../shell/Dashbrd/DB.h" #include "InvExec.h" //----------------------------------------------------------------------------- // Name.......: CGenHeater // Class......: CGenHeater // Description: Constructor // // In.........: None // Out........: None // Return.....: None //----------------------------------------------------------------------------- CGenHeater::CGenHeater() { // get database handles: HOutGenHeat = DB.GetHandle("OutGenHeat"); HGenStatus = DB.GetHandle("GenStatus "); // put into timer loop: LoopMan.AddIoDevice(this, LOOP100); // order a call each 100 ms } //----------------------------------------------------------------------------- // Name.......: TimerCall // Class......: CGenHeater // Description: Constructor // // In.........: int LoopId; Time loop id // Out........: None // Return.....: int loopId //----------------------------------------------------------------------------- int CGenHeater::TimerCall(int LoopId) { if ((FaultTable.GlobalFlags() & faultGRID) || (DB.GetAsInt(HGenStatus) != 0)) { // If grid problems or generator connected, turn off DB.Set(HOutGenHeat, false); // clear output } else { DB.Set(HOutGenHeat, true); // set output } return(LoopId); }

Comment: An instance of the class is defined in a common set-up file, the module is added to the make file and, thus, the object is activated.

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Simulation of a Wind Turbine

Development in Matlab Quest has the capacity to simulate the wind turbine using a mathematical model. This is usually conducted in close cooperation with the manufacturer. The benefits are:  Faster development, less time needed in prototyping and deployment due to the ease

• f verification and testing

 Refinement of control algorithms  Easy and quick test of new ideas The output from Matlab simulations may easily be modified and tested again. There is no need to wait for the right wind conditions!

Fine-tuning a customised algorithm

Refinement of Control Algorithms In the model, new regulator models can be freely tested under all relevant wind and operating

• conditions. Robustness of the control system in

relation to plant differences can be verified. The Matlab Model The rotor torque and speed is calculated from wind input and the turbine’s aerodynamic and mechanical data. The model simulates a drive train with a stiff, heavy turbine, a soft axis, and a perfect gearbox. The generator speed, power and torque are calculated to model an asynchronous, squirrel cage generator. In order to adjust the model for variable speed, only the generator model needs to be changed. A regulator is written in C++ and integrated in the

• model. Effects of sampling interval, noise on input

data, delays in output, etc, can easily be studied.

Turbine:

Stiff, heavy disk

Main shaft:

Limited stiffness and damping

Gearbox:

Ideal transition of speed and torque

Generator:

Speed -> torque and electrical power

Wind:

Step function

Controller:

Uses power, speed and wind data to control pitch angles

Examples On the next page two examples of simulations are

• shown. The comparison to manufacturer data is

made to verify the model. In the first diagram there is a difference at high power that is fully explained by the difference in slip (zero slip makes the model, like most wind mills, unstable). The second diagram illustrates a simple regulator test showing the step response of the system. In addition wind may be modelled as bandwidth limited white noise or true wind traces. Pitch control Pitching equipment may also be simulated in Matlab.

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Matlab Examples

Data for a pitch regulated wind turbine has been fed into the model. The wind is modelled as a step function, with a limited derivative.

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Your Solution?

Blade 1 positioning system DeviceNet

ChorusCPU

DeviceNet B 250 kBit/s DeviceNet A 500 kBit/s 0-1 A AC Hydraulics

• Pump
• Pressure

... RS232 Base panel with some I/O Security loop Remote/park communication line Nacelle panel Power Cabinet Blade 2 positioning system Blade 3 positioning system 4 sliprings

• r

BlueTooth link 4 sliprings Gear Box

• Turbine speed
• Temperatures

... Generator

• Speed
• Temperatures

... Vibration sensor Inverter

ChorusTRAFO

Current transformers 0-10 V AC Opto or radio links RS485

Notes

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Your Solution?

All nacelle IO:

• Digital inputs
• Pumps and valves
• Wind speed and direction,

analog or digital

• Turbine and generator speed
• Temperatures

... Vibration sensor Standard industrial I/O modules Yaw inverters Power cabinet Nacelle panel Control cabinet Base panel ChorusCPU

ChorusTRAFO

ChorusIGNIT

Current trf Contactors etc Copper, optofibre or radio

Security loop RS232 DeviceNet Security loop DeviceNet RS422 Technical specifications are subject to change without notice.