Stability increasing of the synchronous machine by improvment of the excitation system
The influence of capacitive energy storage in the circuit of a synchronous generator excitation on increasing the life activities of independent generating set has been researched. Control criteria of excitation circuit, which should be carried out not only as a function of voltage on the stator but also as a function of the derivative of the electromagnetic torque angle of a synchronous machine have been analyzed.It has been proved that the limited capacity of existing thyris- tor exciters and devices of automatic excitation regulation can be significantly expanded. The most effective way to implement the given problem is excitation forcing with a capacitive compensation of excitation circuit inertia by discharging of a precharged capaci- tive energy storage in this circuit while supplying the forced voltage from thyristor converter. Intensive field discharge of synchronous machine is carried out by the insertion of the excitation circuit of the capacitive element. In this case, the control of synchronous machine excitation is achieved by changing the structure of power converter that provides relay control at high load areas. At low load areas the control of automatic regulation excitation devices is implemented.76Abstract and References. Энергосберегающие технологии и оборудованиеWe analyzed the influence of the electric energy storage capaci- ties for the thyristor conducting interval included in the excitation circuit, on the transient processes in the rotor circuit, in particular on the change of current behavior in the excitation winding in the forcing mode and the magnetic field killing.Developed devices with capacitive energy storage allow au- tomatic regulation of the excitation of synchronous machines, providing high quality transient processes, and improvement of synchronous machines reliability at undervoltage on the stator or at supplying the consumers of considerable power.Adequacy of forcing excitation processes in existing and devel- oped circuits has been studied by proposed device that provides the modes of forcing or field discharge based on the synchronous machine mode. It has been proved that the performance of the forcing process of the excitation current and the magnetic field killing with energy storage is much higher in comparison with existing excitation systems.