Design And Research On Variable Reluctance Resolver For Electric Vehicles

Nowadays, the environmental problem is more and more serious to affect People's lives with science and technology advanced. Energy saving and environmental protection are new requirements for all of industrial production and technological innovation. Electric vehicles were vigorously promoted new energy vehicles in the world. Because it does not emit harmful gases and save the oil resources. Resolver has the advantages of high reliability, high precision, moisture resistance, thermostability and anti vibration to be an angle position sensor. The reluctance resolver is developed on the basis of resolver. It not only inherits the advantages of traditional resolver, but also has a simple structure, lightweight and higher reliability. It has been become the most suitable location/ speed sensor for a permanent magnet motor in electric vehicles.In the present, little literature has been detailed stated about electromagnetic design program of reluctance resolver. Most research aimed to analyze the factors of error. A part of error can be avoided by design, but the actual accuracy is also affected by embedding process and assembly accuracy.For these situations, this paper analyzes the working principle and electromagnetic properties of reluctance resolver. A set of design methods has been summed to find the best values of key parameters in the preliminary design. These parameter-selection law will provide a reference and convenience, with important engineering practice for design.Secondly, the preliminary selected parameter of reluctance resolver has been optimized in order to further improve the measurement accuracy. Firstly,the auxiliary slot has been used in the stator design. The affect of the number and depth of auxiliary slots has been explored on the harmonic content in air gap. Secondly,the best shape of rotor has been found by repeated iteration and contrast. The output waveform is discussed with the situation that windings installation mistake. Meanwhile,the wave winding and the stack winding have been used as the excitation coil winding respectively. And their pros and cons have been discussed in the wind installing process.Finally, a 3X-pole resolver is made according to the design method, and make prototype experiments. The undesirable results have been investigated. The result has shown that the process is also an important factor to ensure the accuracy of the resolver's measurement.