A Distributed Generator Coordinated Control Method Based on Adaptive Dynamic Programming

Abstract

The invention proposes a self-adaptive dynamic planning based coordinative control method of a distributed power generator. By building a large-signal dynamic model of the distributed power generator, a power generator voltage amplitude and a dynamic phase angle tracking error, an approximate optimal performance index function and approximate optimal control rate are designed based on a self-adaptive dynamic planning method, so that a plurality of distributed power supplies are coordinated, the output voltage amplitude and the phase angle are tracked to a leader, the stable frequency and voltage of a microgrid system are maintained, and meanwhile, the load power sharing among all distributed power generators is achieved.

Description

technical field [0001] The invention belongs to the field of smart grid control, and in particular relates to a distributed generator coordination control method based on adaptive dynamic programming. Background technique [0002] In order to improve the utilization rate of new energy and the ability of the large grid to accept renewable energy, small power plants including distributed power sources, energy storage and loads are usually connected to the large grid in the form of microgrids. A microgrid is a small power system that is isolated from the external grid and can operate autonomously. By switching the static switch, it can operate in both island and grid-connected modes. How to make the two modes switch smoothly and ensure the stable operation of the microgrid is very important. When the microgrid operates in the grid-connected mode, its frequency and voltage stability are supported by the large grid. When switching to the island operation mode, the microgrid con...

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Problems solved by technology

Centralized control requires the central controller to collect the operating status information of all distributed generators in a complex two-way communication network environment and issue control commands uniformly. The construction cost is high, and single point failures are prone to occur, which reduces system reliability; In the distributed control mode, the calculation and implementation of the control commands of each distributed generator are completed locally, which has strong scalability. However, in this mode, there is no necessary information interaction between distributed generators, and it is difficult to Coordinating the output of each distributed generator leads to the inability to meet the system operation requirements; while the distributed control mode can manage and control a large number of distributed generators, and only use the neighborhood information to achieve a better control effect, and the cost is low. Strong scalability

[0004] However, the above three modes all rely on the accurately known distributed generator model. Since the parameters of the distributed generator model will change due to factors such as aging and thermal effects, random load disturbances, and the switching of the microgrid’s own operating mode will cause Microgrid system dynamics are uncertain

However, the existing three control strategies cannot compensate the uncertain dynamics of distributed generators, resulting in a decrease in the actual control effect

Therefore, the problem of considering distributed generators with uncertain dynamics and jointly considering their output voltage and frequency stability remains to be solved

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