Ground Fault in the Motor Star Point and Overvoltage Alarm: A
Fault present at startup: The DC bus voltage rises rapidly, exceeding safety limits. This triggers the overvoltage alarm and causes an immediate inverter shutdown.
If that is not possible then, if you have 3 a phase supply, upgrading to a 3 phase inverter usually solves the issue - as the voltage rise is spread over 3 phases. Otherwise you are looking at upgrading your AC cables to the grid or limiting the export power of your solar system.
However, most 3-phase loads are connected in wye or delta, placing constraints on the instantaneous voltages that can be applied to each branch of the load. For the wye connection, all the “negative” terminals of the inverter outputs are tied together, and for the detla connection, the inverter output terminals are cascaded in a ring.
Some inverters will trip or issue an overvoltage fault if the DC bus exceeds a threshold (e.g., 800 V on a 400 V-class inverter). In multi-inverter systems sharing a DC bus, regeneration from one unit can affect others. Solar or battery-connected inverters may have intentionally higher DC bus voltages for MPPT or efficiency reasons.
3. The maximum voltage rise between your solar inverter and the grid is above the 2% maximum in the Australian Standard, because the resistance in the cable (including any connections) is too high. If this is the case then the installer should have advised you that your AC cabling to the grid needed upgrading before solar could be installed.
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