I took a look at the schematic and I don't see anything immediately wrong. I would recommend commenting out the battery model to start and have the model run with only the PV array as the source. Once you confirm that this can provide the correct power load to the motor, work on adding back the battery.
The other thing that comes to mind is that the MPPT algorithm for solar might affect the DC bus voltage, which effects the converter for the battery system. You could change the solar inverter controller to hold a steady DC bus and then use the battery to charge/discharge. You could use something similar to the following example:
>> parallel_battery_SC_boost_converter
