Method and device for processing voltage drop, grid interconnection processing method and device for electrial apparatus, and system

A grid interconnection processing method for an electrical apparatus, comprising:

• acquiring a voltage angle of a power grid;
• under a condition in which the voltage of the power grid does not drop to a threshold value, acquiring the voltage angle, controlling grid interconnection of the electrical apparatus according to the voltage angle, and storing the voltage angle;
• and
• under a condition in which the voltage of the power grid drops to be below the threshold value, controlling the grid interconnection of the electrical apparatus according to a voltage angle stored in a previous time.

A control system, comprising:

• a power generation apparatus, configured to perform power generation, wherein a power sent out by the power generation apparatus is supplied to a switching power supply, and is configured for grid interconnection;
• the switching power supply, connected to the power generation apparatus and a control apparatus, and configured to supply the power to the control apparatus;
• and
• the control apparatus, connected to the switching power supply, wherein the control apparatus comprises at least three inputs, each input is used for inputting a voltage for each phase in a three-phase alternating current, a voltage of the three-phase alternating current is a voltage of a grid interconnection point, the voltage for each phase is configured for obtaining a drop amplitude of the voltage for each phase in the three-phase alternating current, and the drop amplitude of the voltage for each phase is configured as a basis for performing reactive power compensation under a condition in which the voltage of the phase drops.