Research On Arc Protection Of Permanent Magnet Direct Drive Wind Turbine

Wind power has been widely used in recent years.In the early stages of its promotion,the capacity of wind turbines is usually relatively small.As wind power projects continue to increase,the capacity of wind turbines is also increasing.The most commonly used permanent magnet direct-drive wind turbines have a single-unit capacity of 2MW,and large-capacity wind turbines can reach 10 MW or higher,but its corresponding supporting measures have not kept pace with its development.Poor weather conditions can lead to reduced insulation of equipment,such as the plateau area,where the installation of permanent magnet direct-drive wind turbines will reduce the insulation level,and the probability of equipment short-circuit increases;Wind turbines are installed in coastal locations,and humid sea breeze and air will accelerate the reduction of equipment insulation.When the fan is short-circuited due to insulation damage,the internal coil of the generator will over-current,and the traditional temperature sensor in the fan will give an alarm,and the relevant relay protection will act.Since the temperature is an analog signal of the inertia link,the change is insensitive.When a fault is detected,the internal coil of the generator is often burnt due to overcurrent.Due to the motor design of some motor manufacturers,the neutral line of some existing permanent magnet direct-drive wind turbines has not been taken out,which will cause the internal coil of the wind turbine to be short-circuited and the differential protection cannot be installed.The probability of burning will increase dramatically.In order to solve the above problems,this paper proposes a protection scheme for detecting internal short-circuit faults of permanent magnet direct-drive wind turbines by using an arc sensor;the stator winding is established by establishing a mathematical model of permanent magnet direct-drive wind turbine and arc.The short-circuit simulation,the fault characteristics are obtained,and the arc may be formed according to the short-circuit of the permanent magnet direct-drive generator coil.Using its physical characteristics,an arc protection device for the permanent magnet direct-drive wind turbine is designed.The arc protection device adopts the design of STM32F103 R plus TMS320F28335 dual central processor structure,and the human-computer interaction control panel and the measurement and control panel are designed separately.The measurement and control panel is designed with the TMS320F28335 chip of Harvard structure,which mainly realizes the functions of data communication processing,control output processing,collecting current signal and sensor signal processing,and is also the core key of its protection device.The human-computer interaction control panel is designed by STM32F103RBT6 chip produced by STMicroelectronics Group.It mainly realizes the functions of data exchange,key operation,key input processing and liquid crystal display display between the measurement and control panel and RS485 communication interface.The remote monitoring of the arc protection device is designed by the Kingview software launched by Welintech.It can complete the online monitoring of the arc protection device,and the installation plan is determined through the cabin structure to determine the installation position of the device.The overall protection system is protected by remote monitoring and arc protection.The device composition can protect the internal winding of the permanent magnet direct drive wind turbine from short circuit.