Apparatus for controlling the load angle of a converter
AssigneeSiemens Aktiengesellschaft
InventorsGerhard Trauth, Leonhard Reng
Life of this patent
Estimating the term…
Abstract
In order to feed to the converter on the load side of an intermediate-link frequency converter a frequency control signal (fI(S)*) which is formed by means of an angle controller (RW) from the difference of an angle reference value (wi(F)*) and a corresponding actual value (wI(F)), an actual value of the phase current is required which, for stable operation, must not contain heavy harmonics in stable operation nor must not be damped excessively dynamically by smoothing. Therefore, the measured actual angle value (wI(S)) is fed as the reference value of a servo controller (RS), to the output of which the integral (wI(S)*) of the frequency control quantity is added and the output of which is fed back to the input of the servo controller (RS).
Claims4
Apparatus for controlling the load angle of a frequency converter with a-c output, especially for supplying a rotating-field machine comprising:
- an angle detector (MW) for forming an actual angle value (wI(S)) for the phase of the frequency converter output currents;
- an angle controller (RW), having an actual-value input (1) connected to the angle detector, and a reference value input (2) having an angle reference value (wI(F)*) coupled thereto;
- a control unit (STW) having a frequency control input (3) connected to an output of the angle controller and having an output signal (fI(S)*) which controls the frequency converter (WR);
- an angle follower (WIC) connected between the angle detector (MW) and the actual-value input (1) of the angle controller (RW) and comprising:
- a servo control (RS) having an integral portion, and a reference value input fed by the actual angle value (wI(S));
- an adding stage (AD) to which are supplied an output signal of the servo control (RS) and an angle pilot control signal (wI(S)*) which is formed from the output signal of the angle controller (RW) and corresponds to the integral of the frequency converter frequency (fI(S)*), an output of the adding stage being connected to an actual-value input of the servo control (RS) and the actual-value input (1) of the angle controller (RW).
Dependencies are inferred from the claim text.