Starting Performance Analysis of a 2MW Permanent Magnet Synchronous Wind Driven Generator
The cogging torque of PMSM has a great influence on motor operation. It affects the stability of the speed and the dynamic response performance. Therefore, the analysis of cogging torque has always been a key point in the design of PMSM.
For some special applications, such as permanent magnet synchronous wind driven generator, the cogging torque directly affects the starting performance of the motor. The figure below shows the cogging torque curve of a 2WM (56 pole 9.8Hz) permanent magnet synchronous wind driven generator.
Analyze the cogging torque of the motor under different pole arc coefficients, by optimizing the polar arc coefficient and the lamination structure, the wind speed required for starting the motor is reduced, the cogging torque is reduced, and the wind energy absorbing capability is improved.
Demagnetization Analysis of a 70kW Permanent Magnet Synchronous Generator
The following figure shows the simulation analysis of the three-phase sudden short-circuit test for a 70kW permanent magnet synchronous generator. At the moment of short circuit, the permanent magnet synchronous generator will generate a large instantaneous inrush current, and then enter the steady-state short-circuit state, now the winding current is basically the demagnetization current of the magnetic steel. The large current and the steady-state short-circuit current at this moment may cause the irreversible demagnetization of the magnetic steel, it will cause permanent damage. The magnetic density distribution of the magnetic steel after the short circuit is analyzed, and the magnetic density curve of the magnetic steel along the tangential direction of the magnetic steel is also analyzed.
Analyze the magnitude of the inrush current of this motor under the three-phase sudden short-circuit condition, and anti-demagnetization ability of the magnetic steel under the sudden short circuit and the steady-state short circuit, in order to ensure that the magnetic steel works properly under bad conditions.
Dynamic Performance Analysis of a 500W Permanent Magnet Synchronous Motor (Servo Control)
Usually, Cogging torque and parametric nonlinearity of the motor can cause large deviations in steady state and transient performance analysis. In this example, a 500W servo motor is used to analyze the effect of cogging torque on the performance of the servo system.
Under the vector control of PMSM, analyze the influence of cogging torque on the dynamic response performance, including the induced torque and speed fluctuations.
Multi-frequency Analysis of Variable Frequency Induction Motor
We select a 20kW variable frequency induction motor electromagnetic scheme as the analysis object; adopt magnetic circuit method calculation to obtain the working conditions of each frequency point by input frequency characteristics, and obtain the corresponding performance results and curves by analyzing the results of each frequency points.
Obtain the corresponding performance results and curves by calculating, as shown in the following figure:
From the performance data, we can see that the winding terminal voltage is rising continuously under the fundamental frequency (50Hz), and the output torque is maintained at a constant value. Above the fundamental frequency (50Hz), the winding terminal voltage can’t be increased; the output torque continuously decreases during constant output power.
Locked Rotor Analysis of a 2500kW Three-phase Induction Motor with 10kV Rated Voltage
The figure below shows the locked rotor performance analysis of a 2-pole 2500kW three-phase induction motor. For induction motors, considering the excessive starting current during starting, it is necessary to analyze the starting torque and starting current to ensure that the motor has sufficient starting torque within the allowable range of current. Due to the nonlinear saturation of the magnetic field during the normal starting process, the traditional empirical analysis based on the magnetic circuit method is often difficult to obtain accurate results. Therefore, the finite element method is needed to accurately analyze the electromagnetic field.
It is usually difficult to obtain the performance parameters of locked rotor test for the large three-phase induction motor. Through the virtual test platform, the locked rotor torque and the locked rotor current of the three-phase induction motor are accurately simulated and analyzed, and the motor starting performance parameters are obtained.
Speed Fluctuation Analysis of a 1.9kW BLDC Motor (Servo Control)
The figure below shows the current response curve and torque response curve of a 1.9kW BLDC motor using DC chopper control.
Analyze the torque/speed ripple caused by current commutation under the torque closed loop control (speed loop uses PI regulator; current loop uses DC chopper control).
Analyze the dynamic response performance of the servo motor under the DC chopper control, and torque ripple caused by commutation.
Analyze the starting performance of the motor and the torque response fluctuation after sudden load.
The Operation Principle of Universal Motor and Its Finite Element Simulation Analysis
Observe the motor starting and loading operation process by the transient field, and calculate the main technical indexes, such as motor no-load, load speed, efficiency and armature current, etc..
Harmonic Analysis of a 400kW Salient-Poles Synchronous Motor
The figure below shows the air gap magnetic density curve of a 6-pole 400kW salient-poles synchronous motor under the uneven air gap structure. We can accurately analyze the actual air gap magnetic density curve by electromagnetic field, and obtain the influence of air gap magnetic density curve with different conditions such as the saturation of the magnetic circuit, slot type, the height of the air gap magnetic density, uneven air gap, etc.
Analyze the air gap magnetic density curve under the different air gap and damper. The air gap magnetic density curve is improved by adjusting the air gap height, slot pitch and part of material, and the harmonic distortion rate of the no-load electromotive force is also improved for this motor.
The vibration noise problem is a hot spot in the motor industry, which directly affects the quality of the product and the comfort of the user. The following figure shows the obvious noise of a PMSM at 280 Hz, which is tested by spectrum analyzer. First, we extracted the radial electromagnetic force spectrum using the finite element and vibration noise scripts, and found that there is electromagnetic force at a frequency of 280 Hz and the amplitude is large, this causes resonance and forms the noise. By the optimization of the magnetic pole, the electromagnetic force of the 280 Hz frequency is obviously weakened, and the electromagnetic force component is increased but the amplitude is small, which effectively improves the noise problem.
EasiMotor is an easy-to-use and efficient pre-design tool that helps me improve design accuracy in the early stages of motor design, optimize various motor solutions, reduce design costs, and it becomes an essential tool for design work.
— Motor Development Director SHANGHAI ELECTRIC