Island microgrid operation method based on fuzzy PI control

Abstract

The invention discloses an island microgrid operation method based on fuzzy PI control. The method comprises the steps of establishing an island microgrid operation model, wherein an island grid comprises master distributed generation and slave distributed generation; improving a droop controller in a v / f droop control system based on fuzzy PI; controlling operation of the master distributed generation through the droop controller, thereby obtaining voltage amplitude and frequency output by the master distributed generation; and converting the voltage amplitude and frequency into modulation signals and controlling the output power of an inverter of the master distributed generation according to the modulation signals. The fuzzy PI control is added to the droop controller in the v / f droop control system; on the basis of fuzzy reasoning, the droop controller can effectively control the voltage amplitude and frequency output by the master distributed generation; the output voltage amplitude and frequency are converted into the modulation signals; the output power of the master distributed generation can be effectively controlled according to the modulation signals; and the fluctuation of the voltage amplitude and frequency in the operation of the island microgrid can be further inhibited.

Description

Technical field [0001] The invention relates to the technical field of microgrid control, in particular to an island microgrid operation method based on fuzzy PI control. Background technique [0002] In recent years, as environmental and energy issues have become increasingly severe, governments of various countries have begun to vigorously develop and research distributed power generation technologies composed of various renewable energy sources. The microgrid, which is composed of Distributed Generation (DG), energy storage devices, loads, related monitoring and protection devices, through flexible control, can greatly reduce the normal power supply level and safety and reliability of DG's access to the large power grid. The impact. Microgrid has the characteristics of uniqueness, diversity, controllability, interactivity and independence. As an autonomous system, the most important feature of microgrid is independence, that is, the ability to operate in isolated islands. W...

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Problems solved by technology

[0004] When there are frequent or obvious load fluctuations in the microgrid, when the traditional frequency droop feature is used for power regulation, the adjustment range of the frequency droop factor will be limited, and the frequency change may exceed the normal range, resulting in system oscillation

This requires the improvement of the control of the inverter connected to the DG. In the prior art, the PID controller is widely used in the droop control of the inverter because of its simple structure and no static error in the steady state. However, its parameters The selection and tuning process is cumbersome and directly affects the control performance of the inverter, and the flexibility and adaptability of fixed parameters are reduced in the face of microgrid load changes, which shows great limitations

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