Patent ID: 9705406
Date: 2017-07-11
CPC Classifications: H02J,H02M,Y02E

Claim:
1. A DC converter for connecting high-voltage DC networks with different voltages, the converter comprising: a converter series circuit formed of sub-converters connected in series that is arranged between a positive connection terminal and a negative connection terminal of a first DC connection; said converter series circuit having at least two sub-converters arranged as positive pole sub-converters in series between a central connection terminal and said positive connection terminal of said first DC connection; a positive pole power exchanging device connecting said positive pole sub-converters to one another for enabling an exchange of electrical power between said positive pole sub-converters; a potential node between said positive pole sub-converters forming a positive connection terminal of a second DC connection; said converter series circuit having at least two sub-converters arranged as negative pole sub-converters in series between the central connection terminal and said negative connection terminal of said first DC connection; a negative pole power exchanging device connecting said negative pole sub-converters to one another for enabling an exchange of electrical power between said negative pole sub-converters; a potential node between said negative pole sub-converters forming a negative connection terminal of the second DC connection; and an additional power exchanging device connected to said positive pole sub-converters and said negative pole sub-converters for enabling an exchange of power between said positive pole sub-converters and said negative pole sub-converters through said additional power exchanging device; said positive pole power exchanging device including a positive pole transformer, said negative pole power exchanging device including a negative pole transformer, and said additional power exchanging device having a tertiary winding in said negative pole transformer and a tertiary winding in said positive pole transformer; and said tertiary winding in said negative pole transformer and said tertiary winding in said positive pole transformer being conductively connected to one another.