Development and Performance Testing of a $V\!\!/\!f$ Control for Permanent Magnet Synchronous Motor Drives With Wavelet Modulated Power Electronic Converters
S. A. Saleh
Abstract
Volt-per-hertz ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><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 xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$V/f$</tex-math></inline-formula> control for PMSM drives that utilize a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><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 xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$J$</tex-math></inline-formula> ) and scale-time interval factor ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\gamma$</tex-math></inline-formula> ). The output voltage of a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$3\phi$</tex-math></inline-formula> WM dc-ac PEC has its magnitude directly dependent on <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$J$</tex-math></inline-formula> , while its frequency and phase are dependent to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><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 xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$V/f$</tex-math></inline-formula> control for PMSM drives. The proposed <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$V/f$</tex-math></inline-formula> control is featured with a stabilizing loop to correct the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$V/f$</tex-math></inline-formula> ratio, and improve the stability of the controlled PMSM drive. The <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><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 xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><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.