A technology demonstrator with a SD Card flash memory for implementation of three-phase multi-optimal PWM generator

Abstract

This paper investigates for the first time the use of a very large SD Card flash memory to the design of a three-phase Pulse Width Modulation (PWM) generator and describes the hardware and software used for implementation. The new digital architecture differs from conventional counter-based implementation and it follows a pre-programmed optimal PWM pattern that is read from memory with magnitude and phase as coordinates. This architecture allows the inclusion of multiple optimization criteria within the PWM pattern. Experimental results are shown with a PICDEM PIC18 Explorer Board and a SD Card Reader PICtail Daughter Board, both from Microchip. The optimal PWM pattern is defined in MATLAB and the entire design process is described in this paper.

An SD Card Flash-Memory-Based Implementation of a Multioptimal Three-Phase PWM Generator

“…2). This 128-state control sequence can also be seen as a digitization of any already-known PWM algorithm [1], [11]. …”

“…Similar to these references, we will consider the Harmonic Current Factor (HCF) as figure of merit: (1) where V(n) are the voltage harmonics in the phase voltage.…”

“…Conventional SVM with modulation of the sampling frequency [19][20][21][22][23] Our approximation of the sinusoidal variation of frequency with a multistepped waveform. [1] Discontinuous SVM -no-switching (-30,30) [14][15][16][17][18] -pulse freq. scaled by 3/2…”

“…Pulse Width Modulation (PWM) is the most important control component for a three-phase converter [1], [2], [3], [4], [5], [6], [7], [8]. The PWM generator is usually implemented with a digital counter/timer structure.…”

“…The purpose of this paper is to propose and demonstrate a fundamentally new digital architecture [1], [11] for Space Vector PWM (SVPWM) that has the ability to implement complicated, nonlinear algorithms in low cost and simple implementation. Specifically, the advent of large-size flash memories and their cost competitiveness has opened the opportunity for implementation of complex nonlinear control algorithms.…”