Overseas e-commerce platform

Latest updateArticle rankingregister Sign in Contribution

Overseas e-commerce platform

Position: 首页 > generators

What is the late phase operation of generator?

When the generator operates normally, it provides both active power and reactive power to the system

Consult now

When the generator operates normally, it provides both active power and reactive power to the system. The stator current lags behind the terminal voltage by an angle. This state is late phase operation When the excitation current is gradually reduced, the generator changes from providing reactive power to absorbing reactive power from the system, and the stator current changes from lagging to leading the generator terminal voltage, this state is leading phase operation During the leading phase operation of synchronous generator, the excitation current in the later phase operation state is greatly reduced, and the generator potential EQ is also reduced accordingly From the perspective of p-power angle relationship, when the active power remains unchanged, the power angle will increase correspondingly, the ratio of the whole step power will also decrease correspondingly, and the static stability of the generator will decrease Its stability limit is related to generator short circuit ratio, external reactance, performance of automatic excitation regulator and whether it is put into operation The flux leakage at the stator end of the generator increases later in leading phase operation Especially for large generators, the line load is high, the magnetic flux leakage at the end is relatively large during normal operation, and the temperature of the connecting piece of the end iron core pressure finger increases. During leading phase operation, the temperature rise increases due to the increase of magnetic flux leakage During leading phase operation, the voltage at the generator end decreases and the auxiliary power voltage decreases accordingly. If it exceeds 10%, the auxiliary power operation will be affected Therefore, the leading phase operation depth of synchronous generator shall be determined through test That is, under the condition of supplying certain active power, how much reactive power can be absorbed to maintain the static and transient stability of the system, the temperature rise of each component does not exceed the limit, and can meet the voltage requirements What factors restrict the leading phase operation of generator When the inductive reactive power supplied by the system is more than required, the system voltage will rise, requiring the generator to generate less reactive power or even absorb reactive power. At this time, the generator can change from late phase operation to leading phase operation The main factors restricting the leading phase operation of the generator are: (1) the limitation of system stability (2) the limitation of the temperature of the stator end parts of the generator (3) the limitation of the stator current (4) the limitation of the auxiliary power voltage. Why is the iron core at the stator end seriously heated during the leading phase operation of the steam turbine generator? During the operation of the turbogenerator, the leakage magnetic field at the end of the stator winding also rotates the stator at the synchronous speed. Part of the leakage magnetic field forms a magnetic circuit through the space at the end of the stator winding, the rotor retaining ring, air depression and the iron core at the end of the stator. Therefore, eddy current is generated on the plane of the iron core at the end of the stator to generate heat In addition, the excitation winding is close to the retaining ring, so its leakage magnetic field is mainly closed through the retaining ring. When the leading phase operates, due to the reduction of excitation current, the leakage magnetic field at the end of the excitation winding is weakened, so the saturation degree of the retaining ring is reduced, reducing the magnetic group passing through the magnetic circuit at the magnetic leakage site at the end of the stator, resulting in the increase of the leakage magnetic field at the end of the stator and the increase of iron shoots, resulting in the serious heating of the iron core at the end of the stator

label:

Previous : Generator leading phase operat

Home

Next : What is generator non full pha

Recommended for this category