Predictive control method for power grid high frequency stability based on the principle of power flow transfer in isolated grid

Abstract

The invention discloses a power grid high frequency stability prediction control method based on the isolated network tide transfer principle. According to the power grid tide transfer principle existing during sending end stepout or isolated network load trip, electric generator power distribution balance and coordination are transferred through a tide, an assembling unit power control target is predicted, and an assembling unit is rapidly and accurately controlled. The method comprises the following steps that electric generator power, assembling unit revolving speed, power grid power and overspeed protection action signals are collected; power grid high frequency emergency state signals are formed through complex logic operations; the high frequency state signals are broadened; the electric generator power is collected during the broadening period and stored into a memorizer to remain unchanged; the assembling unit power control target is computed according to the memorizer power; during the broadening period, power perdition control is conducted on the assembling unit according to the power control target. The power grid high frequency stable prediction control method based on the isolated network tide transfer principle can greatly improve the high frequency stability level of the power gird and the safety of the assembling unit, has good decentralized coordination, universality, reliability and compatibility, and has good social and economic benefits.

Description

Technical field: [0001] The invention relates to the field of power grid safety control and the thermal control field of a steam turbine generator set, in particular to a power grid high-frequency stability prediction control method based on the principle of isolated grid power flow transfer. Background technique: [0002] From the birth of the power system to the present, the frequency emergency adjustment task has been undertaken by the unit speed control system. From the initial Edison flying pendulum to the current digital electro-hydraulic control system (DEH), although the technology has undergone tremendous changes, the one-time frequency adjustment The control principle has never changed. In principle, primary frequency regulation is to control the deviation of unit power based on frequency offset. In fact, it is an adjustment method of "crossing the river by feeling the stones" when the power grid status changes suddenly and the target of unit power control is not c...

AI Technical Summary

Problems solved by technology

[0007] The technical problem to be solved by the present invention is to provide a power grid high-frequency stability predictive control method based on the principle of isolated grid power flow transfer, to solve the problem that the existing technology adopts the primary frequency modulation technology. When the power imbalance is large, the control response speed of the prime mover is slow, and the adjustment of the prime mover cannot keep up with the change process of the power grid, resulting in a serious speed increase, and the speed is easily higher than 110%, which endangers the safety of the steam turbine blades and causes the emergency shutoff system of the steam turbine Shutdown, which seriously affects the stability of the power grid and when the thermal power unit is disconnected, it is difficult to adjust the boiler fuel and steam pressure to keep up with the steam turbine power adjustment process, and it is easy to cause a surge in steam pressure during the load shedding process, causing safety door operation accidents And other issues

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