Abstract: A method and a system for switching from grid-connected to grid-disconnected, and a power conversion system are provided. The method includes determining whether a power grid is abnormal based on a power grid parameter obtained when a PCS is grid-connected and operates in a current source mode, turning off a switching cabinet if the power grid is abnormal, switching from a current source mode to a voltage source mode, sending a command to instruct a grid-connected/grid-disconnected switch to switch from a grid-connected loop to a grid-disconnected loop, controlling an output parameter to smoothly transit from an abnormal parameter value recorded when the power grid is abnormal to a rated parameter value, and supplying power to a load according to the rated parameter value. In this way, seamless switching from grid-connected to grid-disconnected can be achieved, thereby ensuring stability of power supply.

Abstract: A method and a system for switching from grid-connected to grid-disconnected, and a power conversion system are provided. The method includes determining whether a power grid is abnormal based on a power grid parameter obtained when a PCS is grid-connected and operates in a current source mode, turning off a switching cabinet if the power grid is abnormal, switching from a current source mode to a voltage source mode, sending a command to instruct a grid-connected/grid-disconnected switch to switch from a grid-connected loop to a grid-disconnected loop, controlling an output parameter to smoothly transit from an abnormal parameter value recorded when the power grid is abnormal to a rated parameter value, and supplying power to a load according to the rated parameter value. In this way, seamless switching from grid-connected to grid-disconnected can be achieved, thereby ensuring stability of power supply.

Abstract: A communication method and a communication device based on a parallel system, a terminal and a computer readable storage medium are provided. The parallel system includes a fieldbus and two or more communication nodes connected to the fieldbus in parallel. The communication method includes: acquiring a status parameter of a target communication node; converting the status parameter into a logic level signal; generating an input differential signal based on the logic level signal; sending the input differential signal to the fieldbus and synchronously receiving an output differential signal from the fieldbus, where the output differential signal is generated by the fieldbus by performing a wired-AND operation on input differential signals received from the two or more communication nodes; and acquiring information of the communication nodes connected to the fieldbus based on the output differential signal.

Abstract: A communication method and a communication device based on a parallel system, a terminal and a computer readable storage medium are provided. The parallel system includes a fieldbus and two or more communication nodes connected to the fieldbus in parallel. The communication method includes: acquiring a status parameter of a target communication node; converting the status parameter into a logic level signal; generating an input differential signal based on the logic level signal; sending the input differential signal to the fieldbus and synchronously receiving an output differential signal from the fieldbus, where the output differential signal is generated by the fieldbus by performing a wired-AND operation on input differential signals received from the two or more communication nodes; and acquiring information of the communication nodes connected to the fieldbus based on the output differential signal.