Monos

I looked at the solar panel current using the dessmonitor program. There it is possible to observe in graphic mode separately the incoming current/voltage of the panels, battery charge/discharge current and other parameters.

Two amps of current from the solar panel. I’m talking now only about solar generation, leaving the battery out of the picture. Absolutely right, when talking about power, I mean U * I, which is generated by the solar panel. This is true if the converter is powered from a voltage source. To do this, there must be a capacitive filter at the input of the converter (the same as at the output). But in my inverter, easun 8k max, at the input of the boost converter there is only a 1 µF blocking capacitor to suppress RF oscillations (as at the input of the power factor corrector of a conventional power source). The voltage at the output of the boost converter is formed from the sum of the input voltage and the self-induction emf voltage of the converter choke. Therefore, it is advisable to maintain the voltage on the solar panel as high as possible, while the inductor needs to pump out as much current as possible from the panel in one cycle in order to charge as much energy as possible. Although the panel produces maximum current at short-circuit current, the voltage ripple on the solar panel will be unacceptably high... Today I connected an oscilloscope to the solar input of the inverter. The boost converter there operates at a constant frequency of 20 kHz, only the duty cycle of the pulse changes, depending on the load or illumination. Voltage ripple amplitude is 30...50 volts. In the "90 volt" mode, the ripple is approximately 20 volts. Mode "90 V": Load 3 kW in normal lighting Load 150 W in normal lighting: P. S. The caption to the oscillograms indicates only the power consumed by the 220 volt AC load, without the power required to charge the battery.

As I already said, exit from the “90 volt” mode occurs at approximately 2 amperes of solar generation. Regarding the mppt mode, I believe that with this inverter topology, the generated power does not matter. Since the transfer of energy from the solar panel to the 400 volt dc filter (for further conversion of this voltage into alternating current) occurs by “pumping” the chokes of two boost converters with current. Here is the formula: W = L I² / 2, where W is the energy stored in the inductor, L is the inductance of the inductor, and I is the current through the inductor. As can be seen from this formula, the input voltage level does not matter for the energy in the boost converter. Thus, we can conclude that only the input current from the solar panel is important, and therefore "stuck" at 90 volts does not matter. I hope I managed to get my point across. If I'm wrong, please correct me... P.S. I would like to further develop my idea regarding the incoming voltage from solar panels. The boost converter has three modes of transmitting current to the load: continuous, boundary and discontinuous modes. By choosing the voltage level of the solar panel, you can select the operating mode (current transmission) of the boost converter and thus select the amplitude of the current ripples in the inductor and in the input circuits of the converter. Operating the converter in continuous current mode is preferable, since it causes fewer dynamic losses in semiconductors, losses from the skin effect in wires, etc. But this mode of operation requires either a choke with a higher inductance, or an increase in the conversion frequency of the converter (compared to discontinuous and boundary modes). I think that the MPPT mode in this case is to maintain the converter operating mode in the continuous current mode and reduce the amplitude of the current ripples...

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Thank you very much! I didn't quite understand how to update the display firmware. Do service pack versions 72.66 and 272.66 also include a display update? By watching the MPPT voltage graphs, I found that the solar panel voltage actually lingers at 90 volts. But during this period, the generation of solar energy is very insignificant. As soon as the total current of the panels (PV1+PV2) reaches approximately two amperes, the MPPT voltage jumps to 215 and higher. I don’t observe any problems due to the delay at 90 volts in the morning and evening, but this may be due to high solar activity. I want to see what happens in low clouds and see how much of an impact being stuck at 90 volts has on power generation. The calculated no-load voltage of my solar station is approximately 270 volts (6 panels connected in series with 72 cells each). Energy is generated by five such assemblies.The total power of panels is 9 kW (the actual power output did not reach 7 kW). By the way, on the dessmonitor website I found a tab that offers to update the firmware via Wi-Fi. Has anyone used this update method?

Hello. To update the firmware via USB, as far as I understand, a file with the "hex" extension is needed. It must be placed in the root directory of the flash drive ( F:\new_firmware.hex) . However, the file with the "hex" extension is not found either among the Coulomb patch or among the original 72.66 update files. Tell me, what am I doing wrong?

Thank you very much!

Thank you very much. I have another similar 8kW Sanmart inverter with such firmware: Tell me, does this inverter need a firmware update?

Thank you. If I understand correctly, the firmware version 272.66 complements 72.66. So 272.66 is preferable?

Thank you. Tell me, what is the difference between the corrected version 272.66 from 72.66 and which one is preferable to use?

Hello, please tell me if I need to update the CPU firmware? I use an EASUN ISolar SMW 8K type inverter.