| Summary: | 碩士 === 國立清華大學 === 電機工程學系 === 85 === This thesis presents the design and implementation of a
resonant snubber-based soft switching inverter and its
application to an indirect field-oriented induction motor
drive, such that its switching frequency can be chosen
higher to possess better switching operation character-
istics. First, according to the comparative survey among the
commonly used pulse width modulation(PWM) techniques, the
current-controlled space vector PWM is adopted to let this
proposed soft switching inverter be normally oper- ated and
have good current tracking performance. Compared with the
other existed soft switching techniques, the resonant
snubber-based soft switching is the easiest one to be
implemented, since the soft switching of a tra- ditional PWM
inverter can be successfully achieved by simply adding an
auxiliary resonant circuit and suitable switching control
signals for main and auxiliary switches. The operation,
equivalent circuits and governed equations in various modes of
the proposed soft switching inverter are analyzed in
detail. The accordingly, a systematic design procedure is
proposed to design the components of the auxiliary resonant
circuit and the delay times of switches for achieving zero
voltage transition control. No additional voltage and current
sensors are required. Having tested the validity of the
designed soft switching scheme by simulation, circuit
implementation of the designed soft switching inverter
used in an indirect field-oriented induction motor drive is
performed. Some measured results show that smaller switching
loss and thus higher inverter conversion efficiency are
obtained through using the designed soft switching inverter.
In addition, the current tracking and speed dynamic responses
of the inverter-fed motor drive are not affected by adding the
proposed soft switching scheme.
|
|---|
