Direct-current voltage measurement abnormity judgment device, flexible direct-current system and control method

The invention discloses a DC voltage measurement abnormity discrimination device, a flexible DC system and a control method, and the device comprises an electrical quantity collection module which obtains an electrical quantity signal of the flexible DC system, carries out the digital-to-analog conversion of the electrical quantity signal, and transmits a digital signal to an algorithm control module, the electrical quantity signals comprise grid-side voltage, grid-side current, valve-side current, direct-current voltage and the maximum voltage of the split-phase sub-module of the converter; and the algorithm control module receives the digital signal, carries out judgment operation on the direct current voltage, and replaces the direct current voltage with the maximum voltage of the split-phase sub-module of the converter when the numerical value of the direct current voltage is abnormal so as to carry out closed-loop control on the inner loop current of the flexible direct current system. According to the m