A Generalized Droop Control Method

A control method, a generalized technology, applied in the direction of reducing/preventing power oscillations, etc., can solve problems such as increased construction costs, main power overload, system voltage, frequency fluctuations, etc., to achieve reduced construction costs, lower requirements, and large adjustment margins Effect

CN108551174BActive Publication Date: 2022-03-29NR ELECTRIC CO LTD +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2022-03-29

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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.
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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...

Examples

Embodiment 1

[0022] Example 1: In a microgrid, including power source A, power source B, power source C, power source D and coordination control layer device X, according to image 3 According to the scheme, power supply A and power supply B are set as the main power supply, and the constant voltage control strategy is implemented; power supply C and power supply D are set as non-main power supplies, and the constant power control strategy is implemented; the droop control strategy is implemented in the coordination control layer device X; the total load for P LD and Q LD , where P LD Include the network power loss, Q LD Include the charging power of the network; the total load at the next moment becomes P LD1 and Q LD1 , then the total power output is P LD1 and Q LD1 .

[0023] In the method of the present invention, according to Figure 4 The control flow diagram, the control steps are as follows:

[0024] (1) Detect all power output and system voltage, coordinate the control la...