The Simulink Visualization Simulation Of SFC Device In The Process Of Combustion Engine Start

The starting processes of Gas turbine units refers to the gas turbine units start from static state(turning) to reach a certain speed. In the case of Siemens 9F Type 400 MW heavy-duty Gas turbine unitstarts by using the generator for AC synchronous motor, Using a static frequency conversion device(SFC) as a starter, SFC adds alternating current of the adjustable frequency to the generator stator,it turns the generator into rotational frequency modulation speed regulating motor, drive coaxially to start the Gas Turbine, the alternating current add to the stator which is frequency scaling via frequency converter, makes the starting process according to the preset rate accelerated, the unit of form a complete set of excitation device applies the certain field current to the generator rotor in the starting process,the value of current cooperates with static frequency converter,the works of the excitation device is controlled by the SFC.The static frequency conversion device(SFC) is composed of transformer, DC reactor, rectifier and inverter,the rectifier adopts the three-phase rectifier six pulse controlled thyristor rectifier bridge,the technology will take a constant three-phase AC power into a variable DC power. The inverter also adopts the three-phase rectifier six pulse controlled thyristor rectifier bridge, It converts the DC power output from the rectifier bridge into variable amplitude value and variable frequency AC power, the variable AC power applied to the generator accelerates the generator to the specified speed.There will be lots of harmonic appeared in the process of static frequency converter(SFC) to start the unit, when the electrical equipment within the system constitute one harmonic resonance circuit, the resonance does happen. The resonance makes the motor torque ripple, especially when running at low speed; mechanical resonance phenomenon may be produced.In addition, generator export PT safety fuse often burn-out, incidents such as PT burned.In some cases,generator outage protection action causes trip event.At present, the gas turbine power plant is less in shanghai, most of factory operators are converted from fossil-fuel power station, due to the particularity of the SFC unit, it does not exist in the fossil-fuel power station, so for a lot of gas power plant operators is unknown.The Simulink in Matlab software system was used,referring to the SFC’s internal plant, built a reduction degrees higher analog circuit, input the actual equipment parameters, corresponding rectifier,inverter output voltage and current,harmonic analysis and complete the SFC devices in the visual simulation in the process of combustion engine start.Themanufacturerprovide SFC devices is closed structure, by the electric simulation model, can show the working principle and the actual operation of SFC device to our factory operatorsintuitively and fully, it must bevery good guiding significance. At the same time also can know the voltage in the process of rectifier and inverter harmonic and harmonic suppression,for the operation of the real devices can reference directly, and accurately locate fault linkfor possible higher harmonic surge, find and handle problems in time, so as to maximize the avoid the harmfulness of harmonic voltage to the equipment.