Power control device

Abstract

A power control device for regulating the power that a load consumes on the basis of the AC supply frequency. The system includes decision logic that responds to a frequency deviation to implement a power regulation strategy. The power regulation strategy includes a power compensation phase during which the electrical power that the load consumes is adjusted (reduced or increased) to balance the load on the grid. The power regulation strategy also includes a power restoration phase during which the power to the load is restored (either increased or decreased). The rate at which the power is adjusted during the power compensation phase is higher than the rate at which the power is restored during the power restoration phase.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a controller for controlling the power consumed by a load connected to an AC supply. The invention also extends to control strategies for such load control function. In a specific and non-limiting example of implementation, the invention finds applications in electrical power grids to improve the grid frequency stability.BACKGROUND OF THE INVENTION[0002]To ensure the reliability of an electric power grid, the administrator must continually maintain a power reserve in order to compensate for a possible failure of energy production units. The power reserve is essentially an excess production capacity on standby. In normal conditions, the power generation units are run at less than 100% such that a degree of reserve power is always available. However, the maintenance of this reserve capacity is an expensive proposition since the reserve constitutes a resource that cannot be effectively monetized by the utility company.[0003]A...

AI Technical Summary

Benefits of technology

The patent describes a method to increase the stability of the grid by reducing power demanded by loads. This is done by restoring the load at a slow rate to avoid sudden changes. This approach also allows for quick compensation to address any frequency deviations that may indicate overloaded or underhploaded grids. The patent includes an output to control the power load reduction. In summary, the technical effects of this patent are to enhance the stability of the electricity grid and to improve its resilience by reducing power demanded by loads.

Problems solved by technology

However, the maintenance of this reserve capacity is an expensive proposition since the reserve constitutes a resource that cannot be effectively monetized by the utility company.

Any sudden changes in generation or load resulting in an unbalance between generation and load will lead to a frequency instability during which the frequency deviates from its nominal value.

Large frequency variations are undesirable because they could lead to equipment trip or even a system collapse.

The speed governor however has some inherent limitations.

In particular, it is slow to respond since it involves certain mechanical constraints.

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