Micro electrical network common bus voltage imbalance inhibition method

Abstract

The invention belongs to the distributed power source control technology field in a micro electrical network system and relates to a micro electrical network common bus voltage imbalance inhibition method. According to the method, direct compensation for bus negative phase-sequence voltage at a PPC node in the micro electrical network system is carried out, each distributed power source in the micro electrical network can automatically respond to bus voltage imbalance degree at the PPC node in the micro electrical network system, adaptive adjustment of a negative phase-sequence voltage compensation controller (UVC) is carried out, so each distributed power source carries out negative phase-sequence wattless output according to the rated negative phase-sequence wattless capacity to maintain the voltage balance degree of the bus at the PCC node. Through the method, the parallel distributed power sources in the micro electrical network are enabled to have a function of imbalance voltage inhibition in the micro electrical network.

Description

technical field [0001] The invention belongs to the technical field of distributed power supply control in a microgrid system, and relates to a common bus voltage imbalance suppression method based on the parallel connection of multiple distributed power supplies. Background technique [0002] The widespread use of new energy power generation systems has made the microgrid system based on a variety of distributed power sources, loads and energy storage devices the basic unit of the smart grid. The microgrid system is generally a low-voltage system, and single-phase loads are widely present in the low-voltage system, which leads to the asymmetry of the three-phase output voltage of the three-phase inverter, which causes a large energy loss and affects the stability of the microgrid system. . Therefore, measures must be taken to suppress it to ensure that the distributed power supply maintains a relatively balanced output voltage under unbalanced loads. [0003] Both IEEE an...

AI Technical Summary

Problems solved by technology

The former is rarely used due to high cost and influence on line parameters, while the latter, when the line is seriously unbalanced, the negative sequence current input to the system will increase rapidly, and in severe cases, it will exceed the output limit of the power quality conditioner, causing accidents

Not only that, these two common unbalance compensation devices are only used when the voltage unbalance occurs, but do not work when the system is running normally, the equipment utilization rate is low, and the economic benefit is poor

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