Control apparatus for a converter for transmitting electric power between an alternating voltage network and a direct voltage network
First Claim
1. Control apparatus for a plant converter which connects a direct voltage network to an alternating voltage network comprising:
- first and second current valves connecting said alternating voltage network to a direct voltage network, each of said valves including an electrically controllable breaker connected in parallel with a diode;
means for detecting the level of current flowing through said valves;
means for comparing the level of current flowing through said valves with a first predetermined value, and for detecting which of said valves is conducting said current; and
means for controlling said valves to divert current flowing through said valve conducting current to the other of said valves when the current through a breaker of said valve conducting current exceeds said predetermined value.
1 Assignment
0 Petitions
Accused Products
Abstract
A plant for transmitting electric power between a direct voltage network and an alternating voltage network through a power station. A converter of a station has two current valves connected in series, each having one turn-on and turn-off type breaker and a diode connected anti-parallel therewith. Circuits are provided to detect the direction and the intensity of the current through the converter, as well as the current valve through which it flows to actuate the control apparatus on the basis of the detected current level and the identity of the valve carrying the current. The control apparatus operates to commutate current through the valve which is not carrying current when a detected current level in the current carrying valve exceeds a first predetermined level.
-
Citations
13 Claims
-
1. Control apparatus for a plant converter which connects a direct voltage network to an alternating voltage network comprising:
-
first and second current valves connecting said alternating voltage network to a direct voltage network, each of said valves including an electrically controllable breaker connected in parallel with a diode; means for detecting the level of current flowing through said valves; means for comparing the level of current flowing through said valves with a first predetermined value, and for detecting which of said valves is conducting said current; and means for controlling said valves to divert current flowing through said valve conducting current to the other of said valves when the current through a breaker of said valve conducting current exceeds said predetermined value. - View Dependent Claims (2, 3, 4, 5, 6, 9, 10)
-
-
7. A method for controlling a converter connecting a direct voltage network to an alternating voltage network through first and second serially connected valves comprising:
-
monitoring the current intensity flowing through said first and second valves of said converter; comparing the current intensity with the first intensity level and a second intensity level higher than said first intensity level, both of which are above a normal current intensity; controlling said valves to commutate current through said second valve when the current intensity through a breaker of said first valve exceeds said first intensity level; and blocking said converter if said current through said first valve exceeds said second intensity level. - View Dependent Claims (8)
-
-
11. Control apparatus for a plant converter which connects a direct voltage network to an alternating voltage network comprising:
-
first and second current valves connecting said alternating voltage network to a direct voltage network, each of said valves including an electrically controllable breaker connected anti-parallel with a diode which carry current in opposite directions; means for detecting the level of current flowing through said valves; means for determining when the level of current flowing through said valves exceeds a first predetermined level of current; means for detecting which of said valves is conducting said current; means for determining whether current is flowing through a breaker of said valve or a diode of said valve; means for controlling said valves to divert current flowing through said valve conducting current to the other of said valves when the current through a breaker of said valve conducting current exceeds said predetermined level; and means for blocking said converter when said current flows through a diode of said valve which exceeds said predetermined level. - View Dependent Claims (12, 13)
-
Specification