Method of detecting forward and reverse connection of three-phase motor and solid-state motor starter

A method of detecting forward and reverse connection of a three-phase motor, wherein the three-phase motor is connected to a power supply through a solid-state motor starter comprising a solid-state switch module, a forward and reverse switch module, a first output terminal, a second output terminal and a third output terminal, the solid-state switch module is configured to turn on or off between the power supply and the three-phase motor and comprises a first solid-state switch pair, a second solid-state switch pair and a third solid-state switch pair respectively corresponding to a first phase, a second phase and a third phase of the power supply, the forward and reverse switch module is configured to set the forward and reverse connection of the three-phase motor, the first output terminal, the second output terminal and the third output terminal are respectively configured to connect a first motor terminal, a second motor terminal and a third motor terminal, respectively, the first solid-state switch pair is connected to the first output terminal, and the second solid-state switch pair and the third solid-state switch pair are connected to one of the second output terminal and the third output terminal, respectively, through the forward and reverse switch module,

• wherein the method of detecting comprises:
• turning on the first solid-state switch pair and the second solid-state switch pair into conduction for a predetermined period of time so that current can flow between the power supply and the three-phase motor;
• detecting output current of the solid-state motor starter;
• and
• determining the forward and reverse connection state of the three-phase motor based on the output current of the solid-state motor starter,
• in a case that currents exist at the first output terminal and the second output terminal, it is determined that the three-phase motor is in the forward connection state, and in a case that currents exist at the first output terminal and the third output terminal, it is determined that the three-phase motor is in the reverse connection state.