New PWM switching strategy for microprocessor controlled inverter drives

Influence of multilevel sinusoidal PWM schemes on the performance of a flying-capacitor inverter

“…This can be achieved by cycling each switching state in turn over N cycles for an N-cell inverter. Conventional two-level inverters are commonly controlled to give a sinusoid output voltage using a sinusoidal or sine-triangle PWM control scheme (5 The complexity of the control coupled with the effect of the capacitor voltage variation on the load voltage waveform means that computer simulation is required to fully evaluate the various merits of different SPWM schemes. A simulation program, written in C++, has been developed for carrying out a detailed simulation of an N-cell inverter, including the effect of the cellcapacitor voltage variations.…”

An efficient microprocessor-based pulse-width modulator using space vector modulation strategy

“…For example, if fd is in sector 5 , as shown in Figure 3(a), the two adjacent voltage vectors are VS and v6. starting from time to, fd moves to tl and an approximation for the time integral can then be written as (3) where T5 and T6 represent the time widths for vectors Vs and v 6 respectively and the integration time interval tlto is defined as the Assuming equal time lengths for the two zero vectors, TO and T7 values are then estimated by This procedure is repeated at every sampling interval, i.e. every half of the inverter switching cycle, until the angular position of the modulating signal %t moves into the next sector which relates to vectors v 6 and VI.…”

“…A method for overcoming this is to add a third harmonic component to the fundamental frequency sine wave reference. However, this requires extra computation in a microprocessor-based PWM generation algorithm [2,3]. frequency or index are changed.…”

Nuevos retos en el diseño de redes eléctricas de distribución. Enfoque a la carga, la red y la calidad de la energía eléctrica

“…El algoritmo THIPWM1/4 es idéntico al THIPWM1/6 salvo que la amplitud de la secuencia homopolar es de 1/4. THIPWM1/4 es el algoritmo que consigue el mejor espectro armónico de las corrientes de salida del inversor si bien el rango lineal es menor [125]. Elúltimo algoritmo continuo es el SVPWM(Space Vector PWM) [126].…”