Consistency droop control method for power distribution and voltage frequency recovery

Abstract

The invention provides a consistency droop control method for power distribution and voltage frequency recovery, which is used for an island micro-grid system, realizes accurate active and reactive power sharing, and simultaneously keeps frequency recovery and the average voltage at the rated value. In the proposed control scheme, only the neighborhood reactive power information needs to be exchanged by using a sparse low bandwidth communication network, instead of transferring the information of active power, reactive power and frequency through the communication link in the existing consistency method. Compared with the consistency-based method in the prior art, the transmission data and the data delay are significantly reduced, and the high reliability of the system can be realized. Furthermore, even in the case of the communication delay, accurate active/reactive power sharing and voltage frequency recovery can be ensured under the interference of load and feeder impedances. And finally, a simulation result of the hardware in the ring is given, and the effectiveness of the control scheme is verified.

Description

technical field [0001] The invention belongs to the technical field of microgrids in power systems, and relates to a consistent droop control method for power distribution and voltage frequency recovery. Background technique [0002] In recent years, droop control methods have been widely used to establish system frequency and bus voltage in island-mode microgrids (Microgrids, MGs) and simultaneously control them in distributed generation (DG) units without using critical communications. Active power is shared among them. However, in these methods, voltage and frequency deviations caused by conventional droop control methods are unavoidable, and reactive power sharing is poor under unequal feeder impedance conditions. To solve such problems, typical secondary control strategies are usually used in islanded microgrids to restore the voltage and frequency to rated values ​​to compensate for the limitations of the droop mechanism. Although secondary control strategies can eli...

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Problems solved by technology

However, this method requires a large amount of data information to be exchanged between DGs. Once the communication link fails or there is a communication delay, the stability of the microgrid is easily affected.

[0004] To sum up, the existing ordinary secondary control and consistency control can realize the equal sharing of active / reactive power, but the secondary control often relies on the central controller, which increases the complexity of the system and greatly reduces the reliability of the system ; while ordinary consistency control needs to interact with high-density data to achieve a good control effect. If there is a delay in the interactive data of each DG unit, it will also cause poor control. Moreover, the existing consistency control method lacks a drooping mechanism. The performance of multiple DGs and the stability of the system will also be affected

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