Research On Current Harmonics Suppression Technology Of High-speed Permanent Magnet Synchronous Machine

High Speed Permanent Magnet Synchronous Machine(HS-PMSM)is known for its high power density,small size,high efficiency and fast dynamic response.It is widely used in high-performance machine tools,medical applications,aerospace applications,distributed power generation,and energy applications.Researches into HS-PMSM are currently among the hotspots in the field of electric machines and have received close attention from a large number of research universities and scientific institutions.This dissertation takes high-speed permanent magnet synchronous machine with high-performance drive integrated system as the research object,and aims at solving the problems such as heat alleviation of high-speed motor rotor,the complicated formation mechanism of motor current harmonics,the difficulty of suppressing current harmonics,and relevant problems.Researches were carried out on the estimation method of rotor eddy current loss of high-speed permanent magnet synchronous motor,the formation mechanism of stator winding switching harmonic and its suppression method,low-frequency harmonics suppression of stator winding and high-performance motor drive system for high-speed permanent magnet synchronous motor.Firstly,this dissertation analyzes the mechanism of the space vector modulation method generated harmonics under the presence of the dead zone in detail.For the space vector modulation wave with the presence of dead zone,the double Fourier decomposition is used to analyze the spectral characteristics of the voltage harmonics.Then the formation mechanism of current harmonics is analyzed in depth.The relationship between voltage harmonic components and current harmonic components were studied.A detailed analysis of the reduction of the phase inductance of the motor caused by the eddy current effect in the iron core laminations at high electromagnetic frequencies is made,and the concept of the eddy current equivalent coefficient is proposed to measure the degree of phase inductance reduction as the electromagnetic frequency rises.Aiming at the classic high-speed permanent magnet synchronous motor structure with rotor eddy current copper shielding layer,an analytical model of high-speed permanent magnet synchronous motor based on vector magnetic potential is established,and a high-speed permanent magnet synchronous motor rotor eddy current loss model considering the traveling wave direction of magneto-motive force is proposed.Using the proposed model,the characteristics of rotor eddy current loss caused by different current harmonic types are measured,which provides a basis for the research of high-speed motor stator harmonic suppression methods.Secondly,for the low-frequency harmonic components appearing in the fundamental frequency band,a low-order harmonics suppression method based on Kalman filter is applied;for the change of winding electrical parameters under high-frequency conditions and the weak robustness of the Kalman filter based low-order harmonics compensation scheme against electrical parameter changes,a scheme based on the linear neural network(Adaline NN)algorithm to improve the robustness of the low-order harmonic suppression algorithm is proposed.The effectiveness of the method is verified by computer simulations.Thirdly,in view of the characteristics that switching harmonics of phase current are large and difficult to suppress in stator windings,a method for suppressing current switching harmonics using LCCR filters is proposed.Aiming at the problem that the classic design process of LCCR filter is ineffecient and the overall frequency characteristic is difficult to control,a design method of parameterized LCCR filter is proposed.Simulation and experiments have proved that the proposed method can accurately realize the needed frequency characteristics.On this basis,a harmonic suppression current loop based on optimized damped LCCR is proposed,which can use the high-frequency suppression characteristics of the LCCR filter to suppress the switching harmonics in the current loop.The Nyquist curve method and the root locus method are used to analyze the stability and dynamic response performance of the harmonic suppression current loop.The effect of the switching harmonics suppression performance of the current loop based on the LCCR filter are verified by experiments and simulations.Finally,a high-performance permanent magnet synchronous motor driver based on mixed harmonics suppression technology was trial-produced,and a high-performance permanent magnet synchronous motor system experimental platform was built.On this basis,the suppression performances of the inverter bridge with LCCR filter and the hybrid low-order harmonics suppression algorithm are verified;the changing laws of the electrical parameters of the motor windings under high operating frequency conditions are explored;the high performance current loop controller algorithm is designed,and experiments are conducted to verify the high dynamic performance with low current harmonics of the high-speed motor drive system.