Control method of low-speed stage starting of static frequency conversion starting of pumped storage power station

Abstract

The invention relates to a control method of low-speed stage starting of static frequency conversion starting of a pumped storage power station, comprising the following steps: calculating the initial position of a rotor; estimating each force commutation moment of a low-speed stage inverting bridge according to a preset constant acceleration value; electrifying an appointed two-phase winding at the unlocking moment of a frequency converter according to an interval to which the initial position of the rotor belongs; switching a rectifier bridge to an inversion run mode at the forced commutation moment, sending a trigger pulse to a thyristor bridge arm corresponding to the appointed two-phase winding according to an interval to which a rotor position angle belongs at the moment after a loop of a frequency converter is cut out and each bridge arm of the inverting bridge is reliably shut off, and simultaneously switching the rectifier bridge to a rectifying run mode, and ending single forced commutation; ending the low-speed run stage if the rotor speed is higher than or equal to 5 percent of specific speed of a machine set, and then switching to a natural commutation stage based on machine terminal voltage, or carrying out the forced commutation again; and if starting exceeds time, regulating the preset constant acceleration value, and then restarting until successful starting. The invention can realize rapid and reliable frequency conversion starting at the low-speed stage of the machine set of the pumped storage power station as long as a set value of the constant acceleration of machine set starting is regulated.

Description

technical field [0001] The invention relates to a start control method without a position sensor in the low-speed stage of stationary frequency conversion start of a pumped storage power station, which belongs to the static variable frequency start technology of a pumped storage power station. Background technique [0002] At present, in countries all over the world, static variable frequency start-up is generally used as the preferred starting method for pumped storage power stations. In the automatic control system and complete sets of equipment of pumped storage power stations, static frequency converters are the key starting equipment. It is of great significance for the fast and reliable start-up of energy generating units and the stable operation of pumped storage power plants. For a long time, the control system equipment of my country's large-scale pumped storage power stations has generally been imported from abroad by way of binding bidding with the main engine, an...

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Problems solved by technology

In the natural commutation stage, the machine terminal voltage is relatively high, and the zero-crossing point of the machine terminal voltage signal measured by the voltage transformer can be used as the basis for inverter bridge commutation. The rotor is in a static state. Since the machine terminal voltage is proportional to the frequency when the magnetic flux is constant, the amplitude of the machine terminal voltage is zero, and the machine terminal voltage is also very weak in the low speed stage, resulting in the stator or rotor side current being caused by the rotor The change caused by the position change is also very weak, and it is difficult to obtain the corner position signal from the relevant electrical measurement

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