4results about How to "Solve Oscillation Problems" patented technology

This invention provides a grid-actively supported doubly-fed induction generator (DFIG) wind turbine control system, comprising: a DFIG converter power generation system, a wind turbine primary frequency regulation control module, a wind turbine autonomous inertia response control module, a wind turbine autonomous voltage control module, a rotor-side converter current command generation module, a rotor-side converter current control module, a rotor-side converter signal processing module, a grid-side converter synchronization angle control module, a grid-side converter AC voltage amplitude control module, a grid-side converter current command generation module, a grid-side converter current control module, and a grid-side converter signal processing module. Based on the principle that both the turbine-side and grid-side converters of the DFIG wind turbine employ amplitude and phase control, this invention achieves active support control of the grid frequency and voltage by the DFIG wind turbine unit through active primary frequency regulation, inertia response, and autonomous voltage regulation control strategies, without relying on communication with the power station controller.

The invention discloses a photovoltaic MPPT (Maximum Power Point Tracking) control algorithm, which relates to the technical field of photovoltaic control algorithms, utilizes the characteristics of simple structure, high convergence speed, high global optimization capability, wide applicability and the like of a gradient optimization algorithm, and improves the defects of premature convergence and sensitivity to control parameters of the gradient optimization algorithm. Meanwhile, the photovoltaic output energy efficiency and the stability of the photovoltaic output energy efficiency serve as the evaluation basis, an MPPT algorithm performance evaluation model is constructed through an analytic hierarchy process, photovoltaic MPPT performance is evaluated, and GTO performance is verified and improved.

This invention discloses a control method for switching a dual-wire energy storage inverter from grid-connected to off-grid operation, comprising the following steps: S1: Detecting abnormal grid conditions and disconnecting the grid-connected relay when an abnormality occurs; S2: Determining whether the absolute value of the filter capacitor voltage exceeds a predetermined threshold and whether the discharge time is less than a predetermined time limit; S3: Selecting a corresponding combination of switching transistors for high-frequency drive based on the polarity of the capacitor voltage to reconstruct the full-bridge circuit into a boost circuit; S4: Calculating the duty cycle of the switching transistors based on the dynamic relationship between the capacitor voltage and the bus voltage, and discharging the capacitor energy to the DC bus through the boost circuit; S5: Resetting the output phase angle of the energy storage inverter to zero and starting off-grid operation. This invention effectively solves the problem of voltage oscillation during off-grid startup of residential dual-wire energy storage inverters under various grid-connected to off-grid operating conditions.

The invention relates to the field of servo control, and provides a method and a device for determining a dead time compensation value of an inverter. The method comprises the following steps: determining a three-phase current instruction in a current control loop of the servo system and an actually measured dead zone characteristic curve corresponding to an inverter in the servo system; determining a dead-zone time compensation value of the inverter based on the three-phase current instruction and the actually measured dead-zone characteristic curve; and determining a dead-zone compensation coefficient, and determining a final dead-zone time compensation value based on the dead-zone compensation coefficient and the dead-zone time compensation value. According to the method and the device, the error compensation phenomenon can be avoided to the greatest extent, and the accuracy of dead time compensation is effectively improved.