Apparatus for monitoring and stabilizing power swing in a power system by utilizing a power electronics technique

A power system stabilizing apparatus for a power system in which generators are connected to load systems, comprising:

• at least a semiconductor switch used for stabilizing said power systems;
• means for controlling said semiconductor switch so as to stabilize power swings of said power system, corresponding to operation states of said power system;
• means for detecting voltage changes of said power system, by which occurrence of power swings is monitored and detected based on changes of said detected voltage changes;
• and
• wherein said controlling means controls said semiconductor switch, corresponding to said detected voltage changes.

A power system stabilizing apparatus for a power system in which generators are connected to load systems, comprising:

• at least a semiconductor switch used for stabilizing said power systems;
• means for controlling said semiconductor switch so as to stabilize power swings of said power systems, corresponding to operation states of said power system;
• means for detecting transmitted power changes of said power system;
• and
• wherein said controlling means controls said semiconductor switch, corresponding to said transmitted power changes detected by said transmitted power change detecting means.

A power system stabilizing apparatus for a power system in which generators are connected to load systems, comprising:

• at least a semiconductor switch used for stabilizing said power systems;
• means for controlling said semiconductor switch so as to stabilize power swings of said power system, corresponding to operation states of said power system;
• and
• an energy control type system stabilizing unit with which said semiconductor switch is used, provided at a sending end of a power plant in parallel with a transmission line system connecting a power plant and said load systems, and an acceleration detecting circuit for detecting an acceleration and deceleration of at least one of said generators, wherein said power system is stabilized and power swings are suppressed, by absorbing electric power energy in an acceleration state of said generator and discharging electric power energy in a deceleration state of said generator, by operating said system stabilizing unit.

A power system stabilizing apparatus for a power system in which generators are connected to load systems, comprising:

• at least a semiconductor switch used for stabilizing said power systems;
• means for controlling said semiconductor switch so as to stabilize power swings of said power system, corresponding to operation states of said power system;
• and
• a voltage control type system stabilizing unit with which said semiconductor switch is used, provided at one point of a load system connection point and a midway point between a power plant and said load systems, in parallel with a transmission line connecting said power plant and said load systems, and a voltage detecting circuit for detecting a voltage of said point at which said voltage control type system stabilizing unit is provided, wherein said power system is stabilized and power swings are suppressed, by controlling a voltage of said transmission line by executing absorption of a lead reactive power if said detected voltage is lower than a prescribed level, and of a lag reactive power if said detected voltage is higher than a prescribed level, by operating said system stabilizing unit.

A power system stabilizing apparatus for a power system in which generators are connected to load systems, comprising:

• at least a semiconductor switch used for stabilizing said power systems;
• means for controlling said semiconductor switch so as to stabilize power swings of said power system, corresponding to operation states of said power system;
• and
• one system of a phase control type system stabilizing unit and an impedance control type system stabilizing unit to which said semiconductor switch is used, serially provided in at least one of a plurality of transmission lines connecting said power plant and said load systems via buses, and a power detecting circuit for detecting a power flowing in said transmission line, wherein said power system is stabilized and power swings are suppressed, by controlling a power-flow of said power system so as to keep a prescribed value, by operating said system stabilizing unit.

A power system stabilizing apparatus for a power system in which generators are connected to load systems, comprising:

• at least a semiconductor switch used for stabilizing said power systems;
• means for controlling said semiconductor switch so as to stabilize power swings of said power system, corresponding to operation states of said power system;
• and
• an impedance control type system stabilizing unit to which said semiconductor switch is used, serially provided in a transmission line of a high impedance, and an acceleration detecting circuit for detecting an acceleration and deceleration of at least one of said generators, wherein said power system is stabilized and power swings are suppressed, by absorbing electric power energy in an acceleration state of said generator and discharging electric power energy in a deceleration state of said generator, by operating said system stabilizing unit.

A power system stabilizing apparatus for a power system in which generators are connected to load systems, comprising:

• at least a semiconductor switch used for stabilizing said power systems;
• means for controlling said semiconductor switch so as to stabilize power swings of said power system, corresponding to operation states of said power system;
• and
• a combination of an energy control type system stabilizing unit, a voltage control type system stabilizing unit and an impedance control type system stabilizing unit, having different functions and control rolls, with each of which said semiconductor switch is used, provided at transmission lines to be controlled, wherein said power system is stabilized and power swings are suppressed, by controlling a power-flow of said power system, by operating said semiconductor switch in accordance with a stabilizing command signal obtained by using detected state values of said power system.