3 results about "Unified power flow controller" patented technology

This invention proposes a transformerless medium-voltage power flow transfer device composed of a capacitor switching circuit and a series active circuit. This effectively solves the problems of high cost, large size, and significant operating losses associated with traditional Unified Power Controllers (UPFCs) and back-to-back converters due to the inclusion of isolation transformers. Furthermore, if only a series active circuit is used for active power transmission, reactive power control is difficult, resulting in a low system power factor when there is a large difference in voltage amplitude between the sending and receiving ends. The proposed device, through the coordinated control of a floating module on the sending end and the passive capacitor switching, brings the voltage amplitudes on both sides closer together, significantly suppressing reactive power deviations during active power transmission and improving power quality during power flow control. Finally, the device can perform power flow transfer control regardless of whether the sending-end voltage amplitude is higher or lower than the receiving-end voltage amplitude, offering high flexibility.

The application belongs to the field of electric power engineering, and particularly relates to a unified power flow controller fault prediction system adopting a device fault prediction model, which comprises a data acquisition and processing module, a fault training module and an online monitoring module; the data acquisition and processing module comprises an AC / DC signal acquisition device, a filtering device, a signal processing device and a data storage module; the online monitoring module comprises a state monitoring module, a fault early warning machine and a display module. The application realizes multi-dimensional and all-round UPFC online state monitoring, fault diagnosis and fault early warning, predicts specific fault information of the UPFC device in advance, effectively protects the operation safety of the device, and avoids damage to other power electronic elements caused by UPFC device faults.

The application discloses a disturbance suppression method and system applied to an LCL type unified power flow controller, relates to the technical field of power flow converter power control, and comprises the following steps: constructing an input and output mathematical model of a series side converter system in an s domain according to an LCL type filter, and reducing the order of the input and output mathematical model; performing linear space transformation on the reduced input and output mathematical model, and then compensating for the disturbance generated by the linear space transformation through a state observer LESO; designing a phase lead link based on the frequency characteristics of time delay; calculating current instruction values in a stationary coordinate system according to a power flow equation of the unified power flow controller, and designing a current tracking controller to realize real-time tracking of the current instruction values. The application can solve the technical problem that harmonics affect the output current quality of the series side converter in the related art.