Abstract: The invention discloses a control method and system for improving a transient stability area of a grid-connected inverter. It includes performing park coordinate transformation on a three-phase voltage and a three-phase output current of a connection point of a grid-connected inverter to obtain an actual voltage input value and an actual current input value required for current control; obtaining the grid-connected voltage phase through phase-locked loop processing; generating, by the power control module, the current command value required by the current control module; using the sliding mode current control method, by the current control module, to generate a dq voltage signal, and obtaining PWM modulated voltage control signals through inverse park transformation; using a LCL filter to filter out high-order harmonics to achieve grid-connected control.

Abstract: The present invention discloses an SWRO and MCDI coupled seawater desalination device system with energy recovery, including a pre-filtering unit, an SWRO treatment unit, an MCDI treatment unit, and a post-filtering unit. The SWRO treatment unit is coupled with the MCDI treatment unit. Seawater desalination is performed through a coupling complementary water passage and circuit design, while water quality is improved, and the continuity of water output from a water passage of the device is kept. By recovering the pressure potential energy of high-pressure brine in the SWRO treatment unit and electric energy released by desorption in the MCDI treatment unit, energy consumption is reduced.

Abstract: The present invention discloses an SWRO and MCDI coupled seawater desalination device system with energy recovery, including a pre-filtering unit, an SWRO treatment unit, an MCDI treatment unit, and a post-filtering unit. The SWRO treatment unit is coupled with the MCDI treatment unit. Seawater desalination is performed through a coupling complementary water passage and circuit design, while water quality is improved, and the continuity of water output from a water passage of the device is kept. By recovering the pressure potential energy of high-pressure brine in the SWRO treatment unit and electric energy released by desorption in the MCDI treatment unit, energy consumption is reduced.