04-06-2012, 01:41 PM
A Space Vector Modulation Scheme for Matrix Converter that Gives Top
Priority to the Improvement of the Output Control Performance
A Space Vector Modulation Scheme.pdf (Size: 409.25 KB / Downloads: 35)
Matrix converters capable of AC/AC direct power conversion
have been the subject of much intense R&D work accompanied
in part by advances made in microcomputers and semiconductor
switching devices such as RB-IGBT (Reverse Blocking Insulated
Gate Bipolar Transistors), etc. Matrix converter control methods
can basically be grouped into virtual indirect and direct AC/AC conversion
approach, and many variations have been proposed for each
of these methods.
Virtual indirect conversion method makes use of a virtual rectifier
and inverter. A virtual rectifier controls the input current, and
a virtual inverter on the output regulates the output voltage. Each
type of control is equivalent to the space vector pulse width modulation
(SVPWM) method via an ordinary PWM rectifier/inverter,
offering the advantage that no complicated specialized control is required.
On the other hand, 6 of 27 switching patterns cannot be used
in this method, because the inputs and outputs are always connected
by way of the virtual DC link that is composed of 2 lines. This
constraint might decrease the control degrees of freedom.
In particular, this paper proposes the conversion method of
switching patterns that gives maximum priority to the improvement
of the output control performance. Rendering simultaneous sinusoidal
input and output waveforms as a major premise, voltage fluctuations,
switching losses, output voltage harmonics and commonmode
voltage can be reduced. Figure 3 shows an experi- mental result
of the vector controlled induction motor drive (4-pole, 2.2 kW).
Reduced output line voltage harmonics brings the reduced current
ripple, so the proposed method provides riding comfort for an elevator
application, etc. And the validity of the proposed conversion
method is proven from FFT and THD analysis results compared
with a conventional virtual indirect method that cannot use 6 of 27
switching patterns.