Need suggestions for solar inverter design.

Hello,

I want to design a 3 phase solar inverter. specifications are following.

Input Voltage: 400V DC max.
Output Voltage: 230 V AC, 3 phase.
Functionality: MPPT.

I have started work using PIC18F4550 microcontroller. I am generating PWM pulses. But I am getting many problems in generation of exact duty cycle/timing and v/f. So i want to get suggestions from you that is it okay to go with PIC18F4550 or do I need to change it to dcPIC ?

Also I am unable to get proper support in inverter design with PIC18F4550.
Please suggest me a proper link/application note and microcontroller.

Thanks in advance.