The principle of phase compound excitation device

By motor learning to know, to establish a generator self-excitation and no-load voltage and exciting current must contain the proportional to the voltage of the generator excitation component (called voltage components or light), with a load of the generator, in order to compensate the armature reaction and offset the effects of the impedance voltage drop in armature exciting current but also the current component and load current is proportional to (or called load component).At the same time, from the adjustment of the synchronous generator characteristics = f (I), U = const. Cosp = cons: look, if you want to maintain voltage constant, when the size of the load current phase at the same time, the field current is related to the power factor of load.The relationship is shown in figure 1.

Figure 1 synchronous generator adjustment feature

As a result, the field current and no load components and load the vector relation between the relevant.Taken together,Generator excitation systemAc must consist of two component synthesis in a certain phase relationship.The vector relation as shown in figure 2.

Figure 2 field current vector diagram

Phase compound excitation system is based on this principle.This ac current by two in phase has a certain relationship of components in compound excitation system called phase compound excitation system.Namely the excitation system with phase compensation and electricity compound called phase compound excitation system.

In order to improve the uncontrolled phase compound excitation system voltage regulation accuracy, improve the performance of parallel operation, and then developed the controllable phase compound excitation system.It is on the basis of uncontrolled phase compound excitation system, add a voltage adjuster, controllable phase compound excitation system, voltage corrector is formed according to the principle of negative feedback, but not controllable phase compound is formed according to the disturbance adjusting principle, therefore, controlled phase compound excitation are based on the principles of compound adjustment.

There are many different kinds of controllable phase compound excitation device, various controllable phase compound excitation circuit a lot, the difference between the different lines or measurement in a different way, or the amplification mechanism is different, or correction in a different way, or using different components of each link.

Voltage adjuster for the basic phase compound excitation device correction action can be done by a variety of ways.Principles photogenic each component in a compound device, such as phase compound excitation transformer, current transformer, phase-shifting reactor can be attached to change these components of dc magnetization winding excitation reactance value;Every two components, including ac side and dc side shunt components can be added, such as silicon controlled or saturable reactor, control the shunt.