Assurance of electromagnetic compatibility of powerful electrotechnical systems

The paper describes the main technical means to ensure electromagnetic compatibility of powerful non-linear power consumers - electric arc furnaces and electric rolling mills. Key indicators of two types of reactive power compensating devices are compared: static thyristor compensator and STATCOMs. The authors give the analysis of the main circuits of powerful STATCOMs with different amplitude modulation methods. Special attention is paid to the formation of the input voltage in 12-pulse STATCOMs based on parallel connection of two three-level inverters with center-point current-balancing reactor. It is shown that for a given circuit diagram power switches harmonic content is minimal, they are shifted to 47 and above.