Patent ID: 6084791
Filing Date: 2000-07-04
Classification: H02M

Abstract:
A control arrangement for feeding/recovering energy from a three-phase network into a converter having a variable voltage link, comprising:a phase detector providing, as digital signals, a corresponding present mathematical sign for each phase of the three-phase network;a phase-locked loop producing a binary address signal, the phase-locked loop being synchronized to a detected phase angle and being driven by the corresponding present mathematical sign of one phase of the three-phase network;a function memory element driven by the binary address signal, the function memory element producing at least two digital angular function values having phases which are correct but which are phase-shifted with respect to one another, the function memory element further producing associated digital signals representing respective mathematical signs of the at least two digital angular function values;at least two digital/analog converter stages receiving the at least two digital angular function values and producing at least two analog angular function values;at least two multiplier stages weighting the at least two analog angular function values with a current nominal value, the at least two multiplier stages producing a system of analog alternating current nominal values of a same amplitude, having correct phases, and being phase-shifted with respect to one another;a control comparison stage receiving the system of analog alternating current values and an analog alternating current actual value system, and forming a respective phase-related difference value for each phase of the three-phase network, the analog alternating actual value system being detected by alternating current measurement elements, the control comparison stage producing a respective analog reference signal for each phase of the three-phase network as a function of the respective phase-related difference value;a respective current regulator for each respective phase of the three-phase network, each respective current regulator being driven by the respective analog reference signal corresponding to the respective phase and producing respective drive pulses for a converter active device, the converter active device being coupled to the respective phase on an alternating-current side; anda comparator stage producing an inhibit signal to inhibit the drive pulses for the converter active device when at least one corresponding present mathematical sign from the phase detector differs from a corresponding one of the associated digital signals representing respective mathematical signs of the at least two digital angular function values from the function memory element.