Method for stabilizing a power supply network against reactive load fluctuations, and a power factor compensation device

Power factor compensation device comprising:

• a) at least one installation of variable reactive power,
• b) at least one filter branch with a capacitive reactive power,
• c) at least one power factor compensator which has at least one controller,
• d) a phase-angle controller which is operationally connected on an input side to at least one current transformer for detecting a total current intensity, and on an output side to the at least one controller of the power factor compensator,
• e) the phase-angle controller being operationally connected via a 1st function generator to the at least one controller of the power factor compensator, at which 1st function generator a total reactive power signal Q.sub.G is present on an input side, and a stabilization striking angle signal .alpha..sub.st is emitted on an output side in accordance with
• Q.sub.G .apprxeq..alpha..sub.st .degree./90.degree.-2-(sin 2.multidot.a.sub.st).pi.
• f) the phase-angle controller being operationally connected via a summer to the 1st function generator, and
• g) the summer being operationally connected via a 2nd function generator to the at least one variable reactive load, which 2nd function generator emits a reactive power actual value signal Q.sub.8 as a function of a current actual value signal i.sub.act and a rectifier manipulated variable signal .alpha..sub.act of the at least one variable reactive load in accordance with
• Q.sub.8 =k1.multidot.i.sub.act .multidot.[1-(cos .alpha..sub.act -k2.multidot.i.sub.act).sup.2 ].sup.0.5,
• k1 and k2 being load-specific factors, with 0.1.ltoreq.k1.ltoreq.1 and 0.7.multidot.10.sup.-3 .ltoreq.k2 .ltoreq.1.3.multidot.10.sup.-3.

Method for stabilizing a power supply against reactive load fluctuations of at least one electric device or installation of at least one variable reactive load, comprising the steps of:

• a) controlling current intensity by means of a control signal or manipulated variable signal (.alpha..sub.act) to a prescribable current desired value or reactive power desired value,
• b) compensating reactive power fluctuations produced in the at least one variable reactive load as a function of the manipulated variable signal (.alpha..sub.act) and as a function of a current actual value signal (i.sub.act) or of the current desired value;
• and
• c) compensating the reactive power fluctuations as a function of a total current intensity, which in addition to the current through the at least one variable reactive load, further comprises current through at least one power factor compensation device,
• wherein the reactive power fluctuations are further compensated as a function of a stabilization striking angle signal (.alpha..sub.st), which is formed in accordance with:
• Q.sub.G .apprxeq..alpha..sub.st .degree./90.degree.-2-(sin 2.multidot..alpha..sub.st)/.pi.
• Q.sub.G being a total reactive power signal for the reactive power of an entire variable reactive load in accordance with Q.sub.G =Q.sub.F -Q.sub.8 -Q.sub.des8, with Q.sub.F =filter reactive power signal, Q.sub.8 =reactive power actual value signal and Q.sub.des =desired reactive power signal of the at least one variable reactive load.