MPPT regulates the output voltage and current of the PV array by controlling PWM of the DC-DC converter, enabling the PV module array to always operate near the maximum power point. And the output of the DC-DC converter is the DC bus voltage of the inverter.PWM is by using a fast switching circuit, the time ratio between conduction and cut-off is changed to control the average value of the output voltage. When the conduction time is long, the output voltage is high; when the conduction time is short, the output voltage is low.The more conduction time, then more heat will be generated. The calculation of PWM is that one minus MPPT voltage divided by bus voltage. So less MPPT voltage, PWM will be bigger, then more heat will be generated.For example, If a product has two mppts, one is six hundred Volt, another is five hundred volt. The five hundred volt will occupy more duty cycle of PWM. So for the high temp version, we allow for more MPPT voltage difference. It means, it stands for more heat generation.For DC input, if you look at the efficiency curve and derating curve, you will find the efficiency and derating performance are the best at six hundred volt DC. This is because, line voltage for grid we use four hundred V, the peak of it is around five hundred and sixty volt.And there is an voltage drop of reactor which is around twenty to thirty volt. So in total it is six hundred volt. So the efficiency is the highest at DC six hundred volt. However, no matter at what DC input, inverter should produce same power.If at the DC voltage is bad for inverter efficiency, the efficiency loss will become heat, so there will be more heat. So DC six hundred Volt is better for DC seven hundred for heat dissipation.Furthermore, here is a small radiator at MPPT eleven & twelve and no fans for this radiator. So the heat dissipation ability for this part is not as good as other MPPTs.So in user manual, there is a way for connecting PV string. It has to follow this sequence which helps with heat dissipation.Here is the end of this training. Thank you.