Method for improving sub-synchronous oscillation (SSO) damping of thermal power plant by utilizing fan supplementary controller

Abstract

The invention belongs to the power system field and particularly relates to a method for improving the sub-synchronous oscillation (SSO) damping of a thermal power plant in a wind-thermal power series-compensation combined transmission system by utilizing a supplementary controller to modulate the reactive power output of a wind generation set. The method is based on the rotor current active and reactive decoupling control principle of a double-fed wind generation set, and introduces shafting rotational speed difference of a combined-transmission thermal power plant as the characteristic signal for designing a damping controller, and the output of the damping controller is modulation component under the control of rotor reactive power; and through the regulation on the reactive power of the wind generation set, the effect of enhancing the SSO damping of the combined-transmission thermal power plant is achieved. The invention is applicable to large-capacity wind-thermal power combined series capacitance compensation transmission occasions, so the SSO property of the thermal power plant can be improved, the electric power of a new energy resource is ensured to be transmitted safely, continuously and reliably, and the power system is also ensured to operate safely and stably.

Description

technical field [0001] The invention belongs to the field of power systems, and in particular relates to a method for improving subsynchronous oscillation (Subsynchronous Oscillation, SSO) damping of a grid-connected thermal power unit by using an additional controller for a fan. Background technique [0002] The potential of wind energy utilization is huge. The total exploitable installed capacity of land and offshore wind energy reaches about 700-1.2 billion kilowatts, and the latest assessment report puts forward data that can even reach more than 2.5 billion kilowatts. With the large-scale development of wind farms, the level of research, manufacture and application of wind turbines is also constantly developing, from constant-speed wind turbines with low utilization efficiency of wind energy in the past to variable-speed constant-frequency wind turbines that pursue the maximum conversion efficiency of wind energy. Among them, the megawatt-level wind turbine based on dou...

AI Technical Summary

Problems solved by technology

However, at present, the main grid structure of the power system in areas rich in wind resources is relatively weak. It is a feasible technical measure to install series compensation through the outbound channel to improve the outbound delivery capacity and transmission efficiency of wind and heat bundles.

[0004] Bundling wind and heat in series to supplement external transmission will increase the threat of subsynchronous oscillation of thermal power units at the sending end while improving the external transmission capacity and transmission efficiency of new energy, and will adversely affect the safe and stable operation of the power grid.

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