27-03-2012, 02:31 PM
Simulation and Implementation of Space Vector Pulse Width
Modulation Inverter
Analysis, Simulation and Implementation of Space Vector Pulse Width.pdf (Size: 689.4 KB / Downloads: 241)
Introduction
The inverters are used to convert the dc voltage
into ac voltage with controlled voltage and
frequency. The waveform of the output voltage
depends on the switching states of the six switches.
Many applications of inverters face three major
requirements and limitations [1-4]. The harmonic
contents, the switching frequency, and the best
utilization of dc link voltage. In general, drive
systems with low harmonic contents are better than
that with high harmonic contents. High switching
frequency usually improves the quality of the motor
currents and consequently the whole performance of
the drive system. However, high switching
frequency leads to more switching losses in the
inverter switches.
Voltage-Source Pulse Width Modulation (PWM) Inverter
A typical voltage-source converter performs the
voltage and frequency conversion in two stages: ac
to dc as a first stage and dc to ac for the second
stage. Although the three phase six-step inverter
offers simple control and low switching loss, lower
order harmonics are relatively high resulting in high
distortion of the current wave (unless significant
filtering is performed).
PWM Principle
The dc input to the inverter is “chopped” by
switching devices in the inverter (bipolar transistors,
thyristors, Mosfet, IGBT …etc). The amplitude and
harmonic contents of the ac waveform are controlled
by controlling the duty cycle of the switches. This is
the basic of the pulse width modulation PWM
techniques [1,2].
Sinusoidal PWM
The most popular PWM approach is the sinusoidal
PWM. In this method a triangular (carrier) wave is
compared to a sinusoidal wave of the desired
fundamental frequency and the relative levels of the
two signals are used to determine the pulse widths
and control the switching of devices in each phase
leg of the inverter. Therefore, the pulse width is a
sinusoidal function of the angular position of the
reference signal. The basic principle of three phase
sinusoidal PWM is shown in Fig. 2. The sinusoidal
PWM is easy to implement using analog integrators
and comparators for the generation of the carrier and
switching states.
Inverter Hardware
An intelligent power module (IPM) PM25RSB120
is used to implement the inverter. The power
module is advanced hybrid power devices that
combine high speed, low loss IGBTs with optimized
gate drive and protection circuitry. Highly effective
over-current and short-circuit protection is realized
through the use of advanced current sense IGBT
chips that allow continuous monitoring of power
device current.
Conclusion
Analysis of space vector pulse width modulation is
presented. Different patterns are introduced and the
most effective one is selected. Analysis, modeling
and simulation of the switching intervals generators
Modulation Inverter
Analysis, Simulation and Implementation of Space Vector Pulse Width.pdf (Size: 689.4 KB / Downloads: 241)
Introduction
The inverters are used to convert the dc voltage
into ac voltage with controlled voltage and
frequency. The waveform of the output voltage
depends on the switching states of the six switches.
Many applications of inverters face three major
requirements and limitations [1-4]. The harmonic
contents, the switching frequency, and the best
utilization of dc link voltage. In general, drive
systems with low harmonic contents are better than
that with high harmonic contents. High switching
frequency usually improves the quality of the motor
currents and consequently the whole performance of
the drive system. However, high switching
frequency leads to more switching losses in the
inverter switches.
Voltage-Source Pulse Width Modulation (PWM) Inverter
A typical voltage-source converter performs the
voltage and frequency conversion in two stages: ac
to dc as a first stage and dc to ac for the second
stage. Although the three phase six-step inverter
offers simple control and low switching loss, lower
order harmonics are relatively high resulting in high
distortion of the current wave (unless significant
filtering is performed).
PWM Principle
The dc input to the inverter is “chopped” by
switching devices in the inverter (bipolar transistors,
thyristors, Mosfet, IGBT …etc). The amplitude and
harmonic contents of the ac waveform are controlled
by controlling the duty cycle of the switches. This is
the basic of the pulse width modulation PWM
techniques [1,2].
Sinusoidal PWM
The most popular PWM approach is the sinusoidal
PWM. In this method a triangular (carrier) wave is
compared to a sinusoidal wave of the desired
fundamental frequency and the relative levels of the
two signals are used to determine the pulse widths
and control the switching of devices in each phase
leg of the inverter. Therefore, the pulse width is a
sinusoidal function of the angular position of the
reference signal. The basic principle of three phase
sinusoidal PWM is shown in Fig. 2. The sinusoidal
PWM is easy to implement using analog integrators
and comparators for the generation of the carrier and
switching states.
Inverter Hardware
An intelligent power module (IPM) PM25RSB120
is used to implement the inverter. The power
module is advanced hybrid power devices that
combine high speed, low loss IGBTs with optimized
gate drive and protection circuitry. Highly effective
over-current and short-circuit protection is realized
through the use of advanced current sense IGBT
chips that allow continuous monitoring of power
device current.
Conclusion
Analysis of space vector pulse width modulation is
presented. Different patterns are introduced and the
most effective one is selected. Analysis, modeling
and simulation of the switching intervals generators