On the one hand, the inverter monitors the power generation of the photovoltaic plant, and on the other hand, it also monitors the grid to which it is connected. Therefore, if there is a problem with the grid, it must immediately disconnect the plant from the grid for safety reasons, depending on the requirements of the local grid operator.
In addition, in most cases, the inverter is equipped with a device that can safely interrupt the current flow of the PV modules. Since the photovoltaic module is always active when it emits light, it cannot be switched off. If the inverter cables are disconnected during operation, dangerous arcs can form that cannot be extinguished by direct current. If the circuit breaker is integrated directly in the frequency converter, the installation and wiring work can be significantly reduced.