Safety and stability control method applied to independent power grid

Abstract

The invention relates to the technical field of independent power grid control, in particular to a safety and stability control method applied to an independent power grid. In order to solve the problems existing in operation, namely control, of an enterprise independent power grid in the prior art, the characteristics of an electrolytic aluminum rectification system in the enterprise independentpower grid are utilized, and the principle that different alternating-current power sources operate in parallel on the direct-current side through the rectification system is utilized, so that an alternating-current different-grid and direct-current parallel electrolytic aluminum power supply mode is achieved. In the mode, a control mode of load transfer and load removal under the condition that apower supply fault occurs in the independent power grid is formulated to keep the stability of the power grid, thereby avoiding the risk of full stop of an electrolytic aluminum enterprise and reducing the loss of the electrolytic aluminum enterprise. A rotatable electrolytic aluminum load is formulated according to the accident reserve capacity of a public network power supply, so that the public network plays a load supporting role, the loss load is reduced, the electrolytic aluminum production is ensured not to be fully stopped, the most basic residual load is ensured to ensure the heat preservation security load of an electrolytic cell, and the quick recovery of an independent power grid is facilitated.

Description

technical field [0001] The invention relates to the technical field of independent power grid control, in particular to a safety and stability control method applied to an independent power grid. Background technique [0002] The independent operation of enterprise power grids is relatively weak, and they are always subject to various power disturbances. Different from the conventional large power grid, the load level of the independent grid is low, the installed capacity is small, and even the smallest disturbance, especially the disturbance of power surplus or shortage may cause a large impact on the system. The essence of the enterprise's electrolytic aluminum load is a constant power load, which is not very sensitive to changes in load voltage and frequency. Then, for a specific load level in a specific way, how to achieve precise control of system power and frequency after the system suffers a power disturbance becomes an inevitable problem. [0003] Especially for in...

AI Technical Summary

Problems solved by technology

Existing experience and a large number of analyzes have shown that for independent power grids with relatively weak power supply, tripping of large units often leads to voltage collapse before frequency collapse

For the independent operation of the enterprise power grid, the direct consequence of the voltage collapse is that the load of the induction motor in the grid (including electrolytic aluminum power load and plant power) slips rapidly rises to the point of stalling

[0004] If a unit with a large capacity in the independent power grid, the step-up transformer of the unit fails or the output line trips, the control measures for deep pressure load are adopted, because the output of the faulty unit accounts for a large proportion of the total load, the stability of the power grid It is difficult to guarantee that it will inevitably cause the complete stop of the independent power grid and bring significant economic losses to the enterprise

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