Three-phase four-wire TN-C bus connected dual power conversion circuit

The modular dual power conversion device consists of power electronic control modules and is suitable for TN systems and
TT systems in low-voltage power distribution systems. There are two types of neutral line interruption and non-interruption. Including two methods: prepared self-investment and mutual self-investment. Main power reset
includes manual reset and automatic reset. A double electronic interlock is set up in the module, and an electrical and mechanical interlock is set up in the external circuit to
ensure that the dual power supplies do not communicate with each other. In addition, there is a necessary delay.
    ① Taking into account the short-term normal power loss caused by the normal dispatch of the power grid and the automatic reclosing of the power supply line, in order to avoid
unnecessary conversion of the terminal dual power supply and conversion device, the module is preset for a delay of 2 to 3 seconds.
    ② Consider that a delay of 15 to 30 seconds is required to start the self-provided generator and deliver power normally; if the power generation device has a normal power delivery delay
, the dual power supply conversion delay is still 2-3 seconds.
    The circuit is as shown in the figure. It is a self-reset and self-reset power conversion device, suitable for small capacity (not more
than 100A) dual power conversion boxes. Adopt HZC-21 conversion module.