Method and apparatus for generating a synchronizing signal for a controlled series compensator

Method for generating a synchronizing signal for a firing-circuit subassembly of a controlled series compensator, comprising:

• supplying measured capacitor current of a controlled series compensator serially incorporated into a transmission line to a logic element;
• supplying measured valve current from a power converter valve in said controlled series compensator to said logic element;
• combining said measured capacitor current and said measured valve current in said logic element to form a substitute current signal;
• supplying said substitute current signal to a synchronizing signal generator;
• generating in said synchronizing signal generator a synchronizing signal;
• supplying said synchronizing signal to a firing-circuit subassembly;
• generating in said firing-circuit subassembly firing pulses for said power converter valve in said controlled series compensator;
• such that said substitute current signal is phase-shifted by 90.degree. from a measured capacitor voltage in said controlled series compensator.

An apparatus for generating a synchronizing signal for a firing-circuit subassembly of a controlled series compensator, comprising:

• a controlled series compensator serially integrated into a transmission line, including:
• a capacitor coupled serially within said transmission line, and
• a power converter valve coupled parallel to said capacitor;
• a current detection device coupled to said transmission line and measuring a conductor current of said transmission line;
• a synchronizing signal generator having a current input and a frequency input and generating a synchronizing signal, said current detection device being coupled to said current input of said synchronizing signal generator and supplying said measured conductor current to said synchronizing signal generator, such that said frequency input of said synchronizing signal generator receives a frequency signal from said transmission line;
• and
• a firing-circuit subassembly coupled to said synchronizing signal generator and receiving said synchronizing signal, said firing-circuit subassembly generating firing pulses for said power converter valve in said controlled series compensator, such that said measured conductor current of said transmission line is phase-shifted by 90.degree. from a voltage across said capacitor in said controlled series compensator.

An apparatus for generating a synchronizing signal for a firing-circuit subassembly of a controlled series compensator, comprising:

• a controlled series compensator serially integrated into a transmission line, including:
• a capacitor coupled serially within said transmission line, and
• a series connection comprising a power converter valve coupled in series to a coil, said series connection coupled in parallel to said capacitor;
• a first current detection device coupled to said transmission line and measuring a capacitor current through said capacitor serially coupled within said transmission line;
• a second current detection device coupled to said power converter valve and measuring a valve current through said power converter valve;
• a logic element having first and second inputs and an output, said first input of said logic element receiving said capacitor current from said first current detection device and said second input of said logic element receiving said valve current from said second current detection device, such that said logic element combines said capacitor current and said valve current to form a substitute current signal supplied to said output of said logic element;
• a synchronizing signal generator having a current input and a frequency input and generating a synchronizing signal, said logic element being coupled to said synchronizing signal generator such that said substitute current signal is supplied to said current input of said synchronizing signal generator, such that said frequency input of said synchronizing signal generator receives a frequency signal from said transmission line;
• and
• a firing-circuit subassembly coupled to said synchronizing signal generator and receiving said synchronizing signal, said firing-circuit subassembly generating firing pulses for said power converter valve in said controlled series compensator, such that said substitute current signal is phase-shifted by 90.degree. from a voltage across said capacitor in said controlled series compensator.