Permanent Magnet Generator
The selection of correct generator for the wind turbine system is very important. You need to know either you will apply the generator for battery charging based system or grid-tied system. Our high voltage versions are suitable for grid tied system while the low voltage versions are suitable for battery charging. It is also possible for us to customize the low voltage version to high voltage version, or the high voltage version to low voltage version, to meet your specific requirements. You also need to check if the rotation speed of our generators meet with your system-wise design. For some of our models, we also have two version's mounting way, either for horziontal or for vertical. You need to clarfiy which type you need when you order the products from us.
This is due to the fact that operating at higher voltages result in lower currents. This in turn results in lower resistive losses which is an unavoidable fact at the moment. Components and wires all become cheaper for both the PMG and any connected equipment (especially for higher powered units). With reduced losses, the units can operate with higher efficiency. In fact, our grid tie inverters and PMGs have been designed to complement each other in terms of power and output voltage range.
No, all the major components of the wind turbine has to be considered when designing or buying a good system. The blades set has to be of a good design to maximise the capture of wind energy. The yaw has to be designed properly to protect the system while still maximising energy capture. The overall system has to be strong enough and yet light enough. The electronics have to be of a smart design if possible to maximise the energy conversion / transfer / storage. However, the PMG is a major link in the chain and any weak link in the chain would mean a reduced efficiency of the unit.
The important issues are that PMGs for wind turbines are used in a different location and used in a different way. Wind turbines are driven by wind driving a set of blades not by a machine which has a reasonable amount of torque. Thus, the starting torque of the PMG has to be low in order for the blades to turn at a reasonably low wind speed. Otherwise the turbine will miss out on all the energy at low winds which is present most of the time. It is also working in a harsh environment at heights which is not easily accessbily. Thus, the design has to be reliable and robust enough to withstand what the environment has to throw at it, wide temperature range, humidity, UV exposure etc. If the components used are sub-standard, this will result in down time (worse if the turbine is remotely located which means no one will know about the failure) and maintenance. Use of good components, will result is less frequent down time and less frenquent maintenance which is a cost savings at the end of the day for both the end-user and the wind turbine manufacturer.
No, you need to consider it together with your system to know the output at a certain wind speed. The same generator with different rotor/blade will bring totally different output. We can only offer the output at a certain RPM for the generator itself.
No. It is very imporant for you to design a speed limit equipment when you develop the complete wind turbine system. This kind of mechanism need to be designed with the consideration of other components as a system-wise design.
The starting torque is the torque required to start to rotate the generator when it is still. It is crucial to decide when the wind turbine can start to turn. We had optimized the starting torque to a very low value which will benifit the starting wind speed for your complete wind turbine system.
In most wind turbine designs, the PMG is an integral part of the wind turbine structure. which means that the PMG has to support the weight and all the forces that are experienced by the turbines in strong winds, turbulant winds and high yaw rates. If the PMG is not strong enough to withstand these forces, the PMG might easily break apart and part of the wind turbine might fall off and hurt people, lifestock or damage surrounding properties. For example if the shaft used is not strong thick or strong enough to withstand the yaw forces, it might snap in strong turbulent winds and the blades might fly off and hurt someone as a result.
An slightly higher investment into a better product right at the start of the project will bring about lower down time (as explained above), reduce costs in terms of calling out an engineer to replace or service parts, lower risks, better energy capture etc. If the PMG fails, the turbine will have to be brought down, tested, replaced (which is expensive) or repaired (also expensive) and re-commissioned again. If this is happening because of the manufacturer using a cheap component, then the costs to the end-user does not make sense. A wind turbine is an investment to last a long time. Not like a CD player to be thrown away when a part fails because it is cheaper to buy a new one than to repair it. The cost of a PMG is not significatn when compared to the costs of other parts, installation, electronics, etc.
This is a complicated technical question which has no simple answer. Part of the solution lies with the internal design of the PMG, the windings and the magnets. Part of the answer lies with the mechanical design of the PMG covers and bearings. A major contributing factor is the high quality control employed during the manufacture of the unit. A design is only as good as the quality control behind the manufacturing process. Some of the design to reduce starting torque needs high tolerance and precision during manufacture in order to reduce the starting torque and maximum performance. Therefore, this is a problem that is usually difficult to solve unless the manufacturer has a good knowledge and experience in this field.
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