A Generalized Droop Control Method

Abstract

In a microgrid or an isolated grid, in order to keep the system voltage and frequency stable, a power supply using a droop control strategy is required as the main power supply, which puts high demands on the capacity and regulation ability of the main power supply, which is often difficult to achieve due to economic constraints ideal situation. The present invention proposes a generalized droop control method. The droop control strategy is implemented at the grid coordination control layer to replace the original droop control strategy implemented on the main power supply. All power sources participating in the generalized droop control in the microgrid or isolated grid are divided into Main power supply and non-main power supply, the main power supply accepts the voltage command value issued by the coordination control layer and generates power according to the instruction, and the non-main power supply accepts the power control instruction issued by the coordination control layer and generates electricity according to the instruction. After adopting this strategy, the requirements of the microgrid or isolated grid on the main power supply can be greatly reduced, and at the same time, the coordination control layer can arrange the output according to the actual situation of each power supply in the grid, thereby optimizing the operation results of the grid.

Description

technical field [0001] The invention relates to a power control method for a power source, which is suitable for a micro grid or an isolated grid. Background technique [0002] A microgrid or isolated grid consists of power sources, transmission lines, transformers and loads. In order to keep the voltage and frequency of the power grid stable, in the traditional control method, it is necessary to designate a power supply as the main power supply, and implement a droop control strategy in the main power supply, that is, a control strategy in which the active power is inversely proportional to the frequency, and the reactive power is inversely proportional to the voltage. principle such as figure 1 As shown; other power sources in the grid adopt a constant power control strategy. Traditional control schemes such as figure 2 shown. [0003] When the grid has disturbances such as load fluctuations, power trips, etc., the main power supply in the grid absorbs this part of th...

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Problems solved by technology

[0003] When the grid has disturbances such as load fluctuations, power trips, etc., the main power supply in the grid absorbs this part of the disturbance first. Therefore, when the disturbance is relatively large or the output of the main power supply is close to the rated output before the disturbance, it is easy to overload the main power supply, which will lead to system failure. Large fluctuations in voltage and frequency

In order to reduce or prevent this situation, it is necessary to configure the main power supply capacity as large as possible, which will undoubtedly greatly increase the construction cost

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