Single Phase to Three Phase Converter

The Single phase to Three phase converter using MOSFET, or IGBT with PWM for driving three-phase induction motor by using switching frequency about 7 kHz.  Varying above frequency this results is smooth increasing and decreasing the spindle speed of motor Tree phase motor.  The sinusoidal waveform of three-phase which converted from the single-phase input of the 230 Ac rectified  by bridge diodes.

The gate drive circuit needs to provide an interface between the switching signals coming from the DSP waveform generator and the MOSFET or IGBT in the circuit. The Digital processing from MCU gives a 3.3V signal, while the waveform generators allow for a specified voltage level.

The gate to source voltage needed for desired operation of the MOSFET is on a 110 DC level.   In addition, the high side MOSFET or IGBT  in this circuit do not have the source connected to ground, so the actual voltage needed to drive the gate depends on the varying voltage at the source.

Switching Signal currently small motor drive systems are expensive and implement control schemes that use relatively high switching frequencies such as sine-triangle PWM control. One drawback to the high switching frequencies is the decrease in efficiency that occurs from switching loss.

The control scheme has been used widely and generates little acoustic noise since the switching frequency is on the upper end of the audible acoustic range (20 Hz – 4k – 20 kHz). These control schemes also provide good dynamic performances. However, this application does not need good dynamic performance since there are no dynamic load and speed requirements.
The rating of power element such as gate driver, power MOSFETs or power IGBTs dc bus power supply must be in line with the rating power of three phases induction motor.