Development and Performance Testing of a <inline-formula><tex-math notation="LaTeX">$V\!\!/\!f$</tex-math></inline-formula> Control for Permanent Magnet Synchronous Motor Drives With Wavelet Modulated Power Electronic Converters

Volt-per-hertz (<inline-formula><tex-math notation="LaTeX">$V\!\!/\!f$</tex-math></inline-formula>) control is one the simplest control structures developed for operating electric motor drives, including permanent magnet synchronous motor (PMSM) drives. This paper presents the development and testing of a <inline-formula><tex-math notation="LaTeX">$V\!\!/\!f$</tex-math></inline-formula> control for PMSM drives that utilize a <inline-formula><tex-math notation="LaTeX">$3\phi$</tex-math></inline-formula> wavelet modulated (WM) dc-ac power electronic converter (PEC). The wavelet modulation technique is characterized by the maximum scale (<inline-formula><tex-math notation="LaTeX">$J$</tex-math></inline-formula>) and scale-time interval factor (<inline-formula><tex-math notation="LaTeX">$\gamma$</tex-math></inline-formula>). The output voltage of a <inline-formula><tex-math notation="LaTeX">$3\phi$</tex-math></inline-formula> WM dc-ac PEC has its magnitude directly dependent on <inline-formula><tex-math notation="LaTeX">$J$</tex-math></inline-formula>, while its frequency and phase are dependent to <inline-formula><tex-math notation="LaTeX">$\gamma$</tex-math></inline-formula>. These two parameters of the wavelet modulation technique can be used to implement a <inline-formula><tex-math notation="LaTeX">$V\!\!/\!f$</tex-math></inline-formula> control for PMSM drives. The proposed <inline-formula><tex-math notation="LaTeX">$V\!\!/\!f$</tex-math></inline-formula> control is featured with a stabilizing loop to correct the <inline-formula><tex-math notation="LaTeX">$V\!\!/\!f$</tex-math></inline-formula> ratio, and improve the stability of the controlled PMSM drive. The <inline-formula><tex-math notation="LaTeX">$V\!\!/\!f$</tex-math></inline-formula> control for a PMSM drive fed by a wavelet modulated dc-ac PEC, is implemented for performance testing using a laboratory 10<inline-formula><tex-math notation="LaTeX">$-hp$</tex-math></inline-formula> PMSM drive under different operating conditions. Performance results demonstrate stable, dynamic, and accurate responses, with minor sensitivities to the load torque and/or speed changes. Furthermore, test results demonstrate the ability to enhance the efficiency using the tested control for PMSM drives.