Improved Current Profile Selection for Noise Reduction of Switched Reluctance Motor at Middle Speed Considering Back EMF

Vibration and Acoustic Noise Reduction in Switched Reluctance Motor by Selective Radial Force Harmonics Reduction

“…The next sub-step is calculation of the back electromotive force Vemf by adopting the method explained in a previous study [23]. Next, the calculated Vemf and Vdc are used to predict the actual current waveform i for one period of the electrical rotor position, considering magnetic saturation.…”

“…If Ttarget is achieved, the next stage is the calculation of FrA and its harmonics using Fast Fourier Transformation (FFT). In this case, Taverage and FrA are calculated using the approximations in [23]. An approximation of the radial force is implemented to solve the nonlinear relationship between the radial force, electrical rotor position, and current amplitude.…”

“…Methods 2 and 3 are the radial force sum flattening and selective radial force harmonics reduction. Method 2 is effective in reducing the vibration and acoustic noise at multiples of the 3 rd harmonic [15] - [23]. However, method 2 is ineffective in the test machine because the significant vibration and acoustic noise are not multiples of the 3 rd harmonic.…”

“…In four-phase and five-phase SRMs, the radial force sum flattening reduces the amplitudes at multiples of the 4 th and 5 th harmonics of the radial forces, respectively. Method 2 is effective in three-phase SRMs with high-polenumber configurations, such as 36/24 SRMs [15] - [18],18/12 SRMs [19] - [23], and 24/16 SRM [27]. These motors have the main acoustic noise caused by vibrations in spatial mode 0 at multiples of the 3 rd harmonic.…”

“…Radial force shaping was implemented only in the low back electromotive force condition. In [15] - [23], an effective method called "radial force sum flattening" was proposed. This method significantly reduced vibration and acoustic noise at multiples of the 3 rd harmonic.…”