Multilevel electronic power converter

摘要

The invention is a multilevel electronic DC/AC or AC/DC power converter for n output voltage levels with a positive branch (POS) with a positive DC voltage terminal (2), a negative branch (NEG) with a negative DC voltage terminal (1), and an AC voltage terminal (3) connected to the positive branch (POS) and to the negative branch (NEG), DC bus capacitors (4) interconnected between positive (2) and negative (1) DC voltage terminals and an intermediate DC voltage terminal (5) connected between the two DC bus capacitors (4); a plurality of first external controlled semiconductors (6) and second external controlled semiconductors (7) and, at least, one high-current DC capacitor (11), at least two high-frequency and low-current capacitors (12) and one intermediate controlled semiconductor (8) connected between the intermediate DC voltage terminal (5) and an intermediate terminal (10) of an internal branch (INT) connected in parallel with each high-current DC capacitor (11).

主权项

1. A multilevel electronic DC/AC or AC/DC power converter for n output voltage levels comprising:
a positive branch (POS) with a positive DC voltage terminal (2), a negative branch (NEG) with a negative DC voltage terminal (1), and an AC voltage terminal (3) connected to the positive branch (POS) and to the negative branch (NEG); at least two DC bus capacitors (4) interconnected between the positive DC voltage terminal (2) and the negative DC voltage terminal (1), and an intermediate DC voltage terminal (5) connected between the two DC bus capacitors (4); a plurality of first external controlled semiconductors (6) with antiparallel diodes connected in series in the negative branch (NEG) between the negative DC voltage terminal (1) and the AC voltage terminal (3), and a plurality of second external controlled semiconductors (7) with antiparallel diodes connected in series in the positive branch (POS) between the positive DC voltage terminal (2) and the AC voltage terminal (3); characterized in that it comprises at least two first external controlled semiconductors (6) and at last two second external controlled semiconductors (7); at least one high-current DC capacitor (11) connected between the positive branch (POS) and the negative branch (NEG), and at least two high-frequency and low- current capacitors (12) connected between the positive branch (POS) and the negative branch (NEG) where high-frequency and low-current capacitors (12) only conduct current during the actuation of the switches in order to reduce the overvoltages that appear in the semiconductors during commutation; an internal branch (INT) connected in parallel with each high-current DC capacitor (11) comprising at least two internal controlled semiconductors (9) with antiparallel diodes connected in series and to an intermediate terminal (10); at least one intermediate controlled semiconductor (8) formed by two controlled semiconductors (8a, 8b) with antiparallel diodes and connected in anti-series, connected between the intermediate DC voltage terminal (5) and the intermediate terminal (10) of the internal branch (INT).