DE955521C - Control device for power generators that are excited by self-excited Amplidyne excitation machines - Google Patents

Description

Control device for power generators that operate via self-excited Amplidyne exciters to be excited To reduce the excitation output of excitation machines for power generators one uses Amplidyne exciter machines, which have a much higher degree of amplification (Anchor power: excitation power) and in general also greater excitation speeds possess than normal exciter machines. One achieves that the exciter machine The influencing controller is much smaller and the speed of the control is increased will. It turns out that the self-excitation process - the Amplidyne exciter machine done extremely quickly. However, there is great difficulty in self-excitation Amplidyne by changing a resistance in the field circuit of the Amplidyne to set any desired anchor tension. It. is known this difficulty to bypass the fact that one has the self-excited Amplidyne with two control windings provides, one of which in self-excitation circuit the Amplidyne up to the for the output of the nominal power is excited and the other as an opposing field winding is externally excited, the excitation current of the opposing field winding when the voltage increases of the generator is increased and decreased when the voltage drops. Through this Measure is achieved that even with self-excited Amplidyne exciter machines stable voltage setting is possible and at the same time the generator in the event of a shock load shows an extremely stiff behavior. the Opposing field winding is taken from the generator voltage directly or via magnetic amplifiers or vibration control relay.

With arrangements of this kind it can happen that with a sudden Relief and the sudden rise in voltage caused by it, the counter-excitation reaches such high values that the self-excitation of the Amplidyne exciter The required remanence is destroyed and the exciter is even reversed in polarity.

In order to avoid this, according to the invention, the self-excitation circuit is activated the Amplidyne exciter switched on a rectifier and the current in the Opposite field winding limited.

The rectifier in the self-exciting circuit only allows current to flow in the intended direction so that polarity reversal is ruled out: the limitation of the current in the opposing field winding can be controlled by mechanical means on the voltage regulator or electrically fixed to a certain value, which is so the one to choose is that which is used to generate the three-phase generator voltage when idling required amplidynes voltage is undercut by no more than about 3o to 40'1o.

With a purely electrical control of the counter-excitation, for example by a magnetic amplifier whose output current is the opposing field winding the Amplidyne exciter, the current can be limited in the opposing field winding by non-linear resistors connected in parallel to this, e.g. B. dry rectifier, take place. Dry rectifiers are known to have a current-voltage characteristic with a sharp kink. The rectifier is made by series connection of individual Dimensioning rectifier elements so that the maximum voltage required occurs at the opposite field winding just at the bend of the characteristic. Will now the If the counter-excitation from the voltage regulator is increased beyond this value, the Rectifier suddenly very current-permeable and provides for the opposing field winding a low resistance shunt so that the current in the reverse current winding cannot rise above the intended value.

If an electromagnetic controller is used to control the counter excitation, for example a vibration control relay is used, which has a normally open contact periodically bridged a resistor in the circuit of the opposing field winding, then an additional resistor can be used to limit the current in the opposing field winding be provided, which is dimensioned so that in the event of a short circuit of the controlled by the controller Resistance, the current flowing through the opposing field winding has the required maximum value does not exceed.

Claims (3)

PATENT CLAIMS: r. Control device for power generators that have a self-excited Amplidyne exciter with two control windings are excited, of which the one in self-excitation circuit the Amplidyne up to the one for the Output of the nominal power required value excited and the other as an opposing field winding is externally excited, the excitation thereof taken from the power generation voltage is set automatically by the controller according to a desired dependency, thereby characterized in that a rectifier in the self-excitation circuit of the Amplidyne exciter switched on and the current through the opposing field winding is limited. 2. Control device according to claim r, characterized in that not parallel to the opposing field winding linear resistances, e.g. B. dry rectifier, are connected. 3. Control device according to claim z, in which a regulator has a resistor in the excitation circuit of the opposing field winding periodically bridged; characterized by another of the opposing field winding upstream resistor for current limitation.