String inverters usually have more than 2 MPPTs, and each MPPT usually has 1 or more strings. Each MPPT is independent and has the ability to track and control the changes in output voltage and current. The biggest advantage is that the array is always kept in the maximum output working state, which we call maximum power point tracking. Different MPPTs are connected in multiple directions, shadows, inconsistent string lengths, inconsistent angles, etc.
In the case of voltage parallel mismatch, the MPPT maximum power tracking points are different. The lower voltage will pull down the higher voltage, affecting the overall output power.
It is not recommended to do so, because different power components mean different working currents. If connected in series, the entire string will follow the current of the smallest component. The greater the power difference, the greater the current difference.
The maximum allowable current measured by short-circuiting the positive and negative poles is the maximum short-circuit current, and the maximum operating current refers to the maximum output current value allowed for the string operation.
Whether the surplus power is connected to the grid or the full amount is mainly determined by whether the grid connection point is at the front or back end of the load. It has nothing to do with the inverter, so there is no need to change the inverter. If you applied for full amount of grid connection before, you need to go to the power supply company to apply for surplus power to the grid again.
They can share the same inverter, provided that the components on different slopes need to be placed in different MPPTs, and the number and orientation of each component under the same MPPT must be kept consistent.
The power generation efficiency affected by different longitudes and latitudes is different. Take Jinan as an example (facing due south, under the same conditions, 30 degrees is the best inclination angle, without loss of power generation). If the component inclination angle is 50 degrees, the power generation loss is 4%; the inclination angle is 40 degrees, the power generation loss is 0.9%; the inclination angle is 20 degrees, the power generation loss is 1.3%; the inclination angle is 10 degrees, the power generation loss is 4.6%.
The inverter grounding and the shell grounding are not connected to the same place, they need to be separated. The former is the working grounding (which can maintain the non-fault relative ground voltage unchanged; can ensure the accuracy of the relatively low voltage measurement in the primary system; discharge the lightning current to the ground when lightning strikes), and the latter is the protective grounding (to ensure personal safety and avoid or reduce the harm of accidents, protective grounding is often used in electrical engineering).
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