2results about How to "Fast steady state" patented technology

The application provides a grid-connected inverter adaptive virtual impedance stabilizing control method and system, obtains a grid-connected point voltage amplitude, an inverter side current amplitude and a power angle, calculates a grid impedance amplitude according to the grid-connected point voltage amplitude, the inverter side current amplitude and the power angle, records a calculated value as a grid impedance initial amplitude and saves the grid impedance initial amplitude when the calculated grid impedance amplitude reaches stability for the first time, obtains a difference value of the impedance amplitude by subtracting the grid impedance initial amplitude from the calculated grid impedance amplitude, judges whether the impedance amplitude difference satisfies a limited condition, outputs the impedance amplitude difference if the condition is satisfied, and otherwise outputs a set value; and sets control parameters of a virtual impedance link in front of a voltage and current double closed loop control according to the output, so that the application adjusts the virtual impedance in real time, reduces overshoot in a transient process of SCR switching, and suppresses power oscillation of the system.

The application provides a grid-connected inverter extreme working condition adaptive power angle compensation stable control method and system, calculates active power and reactive power output by the grid-connected inverter; compares the grid voltage amplitude, when the grid voltage amplitude is greater than the threshold value, virtual synchronous generator control is adopted, a power ring generates an internal potential signal and a phase signal, a modulation signal is generated through a virtual impedance and a voltage and current double closed loop part, otherwise, a fault ride-through control is started, an active ring is frozen, the power reference value of the active ring is replaced by the active power output by the grid-connected inverter, and adaptive power angle compensation control is put into the active ring; after the grid voltage returns to the normal range, the fault ride-through mode is kept until the system enters the steady state, the adaptive power angle compensation stable control is exited, the active ring is restarted, and the virtual synchronous generator control mode is entered. The application ensures that the VSG can still be grid-connected during the fault period, and fully plays the active power output capacity of the VSG.