Control equipment for high voltage direct current transmission system with equipment of self-commutated converter

Claim 2

A control equipment for a high voltage direct current (hvdc) transmission system having an equipment of self-commutated converter which comprises switching devices with a self-commutating function and is operated as a rectifier or an inverter, said control equipment comprising: first control means for controlling a first equipment of self-commutated converter, operated as said rectifier, in such a manner as to hold the dc voltage of a dc system in said high voltage dc transmission system and the reactive power on the input side of said first equipment of self-commutated converter at specified values, and second control means for controlling a second equipment of self-commutated converter, operated as said inverter, in such a manner as to hold the active power and the reactive power on the output side of said second equipment of self-commutated converter at specified values, wherein said first control means includes first current control means for independently controlling each current signal for said first equipment derived from two-phase current signals transformed from three-phase alternating current signals, and said second control means includes second current control means for independently controlling each current signal for said second equipment derived from the two-phase current signals transformed from the three-phase alternating current signals.

Claim 3

A control equipment for a high voltage direct current (hvdc) transmission system having an equipment of self-commutated converter which comprises switching devices with a self-commutating function and is operated as a rectifier or an inverter, said control equipment comprising: first control means for controlling a first equipment of self-commutated converter, operated as said rectifier, in such a manner as to hold the dc voltage of a dc system in said high voltage dc transmission system and the ac system voltage on the input side of said first equipment of self-commutated converter at specified values, and second control means for controlling a second equipment of self-commutated converter, operated as said inverter, in such a manner as to hold the active power and the line voltage of an ac system on the output side of said second equipment of self-commutated converter at specified values, wherein said first control means includes first current control means for independently controlling each current signal for said first equipment derived from two-phase current signals transformed from three-phase alternating current signals, and said second control means includes second current control means for independently controlling each current signal for said second equipment derived from the two-phase current signals transformed from the three-phase alternating current signals.

Claim 4

A control equipment for a high voltage direct current (hvdc) transmission system having an equipment of self-commutated converter which comprises switching devices with a self-commutating function and is operated as a rectifier or an inverter, said control equipment comprising: first control means for controlling a first equipment of self-commutated converter, operated as said rectifier, in such a manner as to hold the dc voltage of a dc system in said high voltage dc transmission system and the ac system voltage on the input side of said first equipment of self-commutated converter at specified values, and second control means for controlling a second equipment of self-commutated converter, operated as said inverter, in such a manner as to hold the active power and the line voltage of an ac system on the output side of said second equipment of self-commutated converter at specified values, wherein said first control means includes first current control means for independently controlling each current signal for said first equipment derived from two-phase current signals transformed from three-phase alternating current signals, and said second control means includes second current control means for independently controlling each current signal for said second equipment derived from the two-phase current signals transformed from the three-phase alternating current signals.

Claim 5

A control equipment for a high voltage direct current (hvdc) transmission system having an equipment of self-commutated converter which comprises switching devices with a self-commutating function and is operated as a rectifier or an inverter, said control equipment comprising: first control means for controlling a first equipment of self-commutated converter, operated as said rectifier, in such a manner as to hold the active power and the reactive power on the input side of said first equipment of self-commutated converter at specified values, and second control means for controlling a second equipment of self-commutated converter, operated as said inverter, in such a manner as to hold the dc voltage of a dc system in said high voltage dc transmission system and the reactive power on the output side of said second equipment of self-commutated converter at specified values, wherein said first control means includes first current control means for independently controlling each current signal for said first equipment derived from two-phase current signals transformed from three-phase alternating current signals, and said second control means includes second current control means for independently controlling each current signal for said second equipment derived from the two-phase current signals transformed from the three-phase alternating current signals.

Claim 6

A control equipment for a high voltage direct current (hvdc) transmission system having an equipment of self-commutated converter which comprises switching devices with a self-commutating function and is operated as a rectifier or an inverter, said control equipment comprising: first control means for controlling a first equipment of self-commutated converter, operated as said rectifier, in such a manner as to hold the active power and the reactive power on the input side of said first equipment of self-commutated converter at specified values, and second control means for controlling a second equipment of self-commutated converter, operated as said inverter, in such a manner as to hold the dc voltage of a dc system in said high voltage dc transmission system and the reactive power on the output side of said second equipment of self-commutated converter at specified values, wherein said first control means includes first current control means for independently controlling each current signal for said first equipment derived from two-phase current signals transformed from three-phase alternating current signals, and said second control means includes second current control means for independently controlling each current signal for said second equipment derived from the two-phase current signals transformed from the three-phase alternating current signals.

Claim 7

A control equipment for a high voltage direct current (hvdc) transmission system having an equipment of self-commutated converter which comprises switching devices with a self-commutating function and is operated as a rectifier or an inverter, said control equipment comprising: first control means for controlling a first equipment of self-commutated converter, operated as said rectifier, in such a manner as to hold the active power and the line voltage of an ac line on the input side of said first equipment of self-commutated converter at specified values, and second control means for controlling a second equipment of self-commutated converter, operated as said inverter, in such a manner as to hold the dc voltage of a dc system in said high voltage dc transmission system and the ac system voltage on the output side of said second equipment of self-commutated converter at specified values, wherein said first control means includes first current control means for independently controlling each current signal for said first equipment derived from two-phase current signals transformed from three-phase alternating current signals, and said second control means includes second current control means for independently controlling each current signal for said second equipment derived from the two-phase current signals transformed from the three-phase alternating current signals.

Claim 8

A control equipment for a high voltage direct current (hvdc) transmission system having an equipment of self-commutated converter which comprises switching devices with a self-commutating function and is operated as a rectifier or an inverter, said control equipment comprising: first control means for controlling a first equipment of self-commutated converter, operated as said rectifier, in such a manner as to hold the active power and the line voltage of an ac line on the input side of said first equipment of self-commutated converter at specified values, and second control means for controlling a second equipment of self-commutated converter, operated as said inverter, in such a manner as to hold the dc voltage of a dc system in said high voltage dc transmission system and the ac system voltage on the output side of said second equipment of self-commutated converter at specified values, wherein said first control means includes first current control means for independently controlling each current signal for said first equipment derived from two-phase current signals transformed from three-phase alternating current signals, and said second control means includes second current control means for independently controlling each current signal for said second equipment derived from the two-phase current signals transformed from the three-phase alternating current signals.

Claim 9

A control equipment for a high voltage direct current (hvdc) transmission system in which a converter equipment operated as a rectifier is constituted by an equipment of line-commutated converter, and a converter equipment operated as a inverter is constituted by an equipment of self-commutated converter which comprises switching devices with a self-commutating function, said control equipment comprising: first control means for controlling a first equipment of line-commutated converter, operated as a rectifier, in such a manner as to hold the dc voltage of a dc system in said high voltage dc transmission system at a specified value, and second control means for controlling said equipment of self-commutated converter, operated as an inverter, in such a manner as to hold the active power and the reactive power on the output side of said equipment of self-commutated converter at a specified value, wherein said first control means includes first current control means for independently controlling each current signal for said first equipment derived from two-phase current signals transformed from three-phase alternating current signals, and said second control means includes second current control means for independently controlling each current signal for said equipment of self-commutated converter derived from the two-phase current signals transformed from the three-phase alternating current signals.

Claim 10

A control equipment for a high voltage direct current (hvdc) transmission system in which a converter equipment operated as a rectifier is constituted by an equipment of line-commutated converter, and a converter equipment operated as a inverter is constituted by an equipment of self-commutated converter which comprises switching devices with a self-commutating function, said control equipment comprising: first control means for controlling a first equipment of line-commutated converter, operated as a rectifier, in such a manner as to hold the dc voltage of a dc system in said high voltage dc transmission system at a specified value, and second control means for controlling said equipment of self-commutated converter, operated as an inverter, in such a manner as to hold the active power and the reactive power on the output side of said equipment of self-commutated converter at a specified value, wherein said first control means includes first current control means for independently controlling each current signal for said first equipment derived from two-phase current signals transformed from three-phase alternating current signals, and said second control means includes second current control means for independently controlling each current signal for said equipment of self-commutated converter derived from the two-phase current signals transformed from the three-phase alternating current signals.

Claim 11

A control equipment for a high voltage direct current (hvdc) transmission system in which a converter equipment operated as a rectifier is constituted by an equipment of line-commutated converter, and a converter equipment operated as a inverter is constituted by an equipment of self-commutated converter which comprises switching devices with a self-commutating function, said control equipment comprising: first control means for controlling said equipment of line-commutated converter, operated as a rectifier, in such a manner to hold the dc voltage of a dc system in said high voltage dc transmission system at specified values, and second control means for controlling said equipment of self-commutated converter, operated as an inverter, in such a manner as to hold the active power and the line voltage of an ac line on the output side of said equipment of self-commutated converter at a specified value, wherein said first control means includes first current control means for independently controlling each current signal for said equipment of line-commutated converter derived from two-phase current signals transformed from three-phase alternating current signals, and said second control means includes second current control means for independently controlling each current signal for said equipment of self-commutated converter derived from the two-phase current signals transformed from the three-phase alternating current signals.

Claim 12

A control equipment for a high voltage direct current (hvdc) transmission system in which a converter equipment operated as a rectifier is constituted by an equipment of line-commutated converter, and a converter equipment operated as a inverter is constituted by an equipment of self-commutated converter which comprises switching devices with a self-commutating function, said control equipment comprising: first control means for controlling said equipment of line-commutated converter, operated as a rectifier, in such a manner to hold the dc voltage of a dc system in said high voltage dc transmission system at specified values, and second control means for controlling said equipment of self-commutated converter, operated as an inverter, in such a manner as to hold the active power and the line voltage of an ac line on the output side of said equipment of self-commutated converter at a specified value, wherein said first control means includes first current control means for independently controlling each current signal for said equipment of line-commutated converter derived from two-phase current signals transformed from three-phase alternating current signals, and said second control means includes second current control means for independently controlling each current signal for said equipment of self-commutated converter derived from the two-phase current signals transformed from the three-phase alternating current signals.

Claim 13

A control equipment for a high voltage direct current (hvdc) transmission system in which a converter equipment operated as a rectifier is constituted by an equipment of line-commutated converter, and a converter equipment operated as a inverter is constituted by an equipment of self-commutated converter which comprises switching devices with a self-commutating function, said control equipment comprising: first control means for controlling said equipment of line-commutated converter, operated as a rectifier, in such a manner as to hold the active power on the input side of said equipment of line-commutated converter at a specified value, and second control means for controlling said equipment of self-commutated converter, operated as an inverter, in such a manner as to hold the dc voltage of a dc system in said high voltage dc transmission system and the reactive power on the output side of said equipment of self-commutated converter at specified values, wherein said first control means includes first current control means for independently controlling each current signal for said equipment of line-commutated converter derived from two-phase current signals transformed from three-phase alternating current signals, and said second control means includes second current control means for independently controlling each current signal for said equipment of self-commutated converter derived from the two-phase current signals transformed from the three-phase alternating current signals.

Claim 14

A control equipment for a high voltage direct current (hvdc) transmission system in which a converter equipment operated as a rectifier is constituted by an equipment of line-commutated converter, and a converter equipment operated as a inverter is constituted by an equipment of self-commutated converter which comprises switching devices with a self-commutating function, said control equipment comprising: first control means for controlling said equipment of line-commutated converter, operated as a rectifier, in such a manner as to hold the active power on the input side of said equipment of line-commutated converter at a specified value, and second control means for controlling said equipment of self-commutated converter, operated as an inverter, in such a manner as to hold the dc voltage of a dc system in said high voltage dc transmission system and the reactive power on the output side of said equipment of self-commutated converter at specified values, wherein said first control means includes first current control means for independently controlling each current signal for said equipment of line-commutated converter derived from two-phase current signals transformed from three-phase alternating current signals, and said second control means includes second current control means for independently controlling each current signal for said equipment of self-commutated converter derived from the two-phase current signals transformed from the three-phase alternating current signals.

Claim 15

A control equipment for a high voltage direct current (hvdc) transmission system in which a converter equipment operated as a rectifier is constituted by an equipment of line-commutated converter, and a converter equipment operated as a inverter is constituted by an equipment of self-commutated converter which comprises switching devices with a self-commutating function, said control equipment comprising: first control means for controlling said equipment of line-commutated converter, operated as a rectifier, in such a manner as to hold the active power on the input side of said equipment of line-commutated converter at a specified value, and second control means for controlling said equipment of self-commutated converter, operated as an inverter, in such a manner as to hold the dc voltage of a dc system in said high voltage dc transmission system and the ac system voltage on the output side of said equipment of self-commutated converter at specified values, wherein said first control means includes first current control means for independently controlling each current signal for said equipment of line-commutated converter derived from two-phase current signals transformed from three-phase alternating current signals, and said second control means includes second current control means for independently controlling each current signal for said equipment of self-commutated converter derived from the two-phase current signals transformed from the three-phase alternating current signals.

Claim 16

A control equipment for a high voltage direct current (hvdc) transmission system in which a converter equipment operated as a rectifier is constituted by an equipment of line-commutated converter, and a converter equipment operated as a inverter is constituted by an equipment of self-commutated converter which comprises switching devices with a self-commutating function, said control equipment comprising: first control means for controlling said equipment of line-commutated converter, operated as a rectifier, in such a manner as to hold the active power on the input side of said equipment of line-commutated converter at a specified value, and second control means for controlling said equipment of self-commutated converter, operated as an inverter, in such a manner as to hold the dc voltage of a dc system in said high voltage dc transmission system and the ac system voltage on the output side of said equipment of self-commutated converter at specified values, wherein said first control means includes first current control means for independently controlling each current signal for said equipment of line-commutated converter derived from two-phase current signals transformed from three-phase alternating current signals, and said second control means includes second current control means for independently controlling each current signal for said equipment of self-commutated converter derived from the two-phase current signals transformed from the three-phase alternating current signals.

Claim 17

A control equipment for a high voltage direct current (hvdc) transmission system having an equipment of self-commutated converter which comprises switching devices with a self-commutating function and is operated as a rectifier or an inverter, said control equipment comprising: first control means for controlling a first equipment of self-commutated converter, operated as said rectifier, in such a manner as to hold the dc voltage of a dc system in said high voltage dc transmission system and the reactive power on the input side of said first equipment of self-commutated converter at specified values, and second control means for controlling a second equipment of self-commutated converter, operated as said inverter, in such a manner as to hold the active power and the reactive power on the output side of said second equipment of self-commutated converter at specified values, wherein said first control means comprises dc voltage control means for amplifying a difference between said specified value of the dc voltage applied from input means and a detected output from dc voltage detective means, d-axis current control means for amplifying a difference between an output of said dc voltage control means and a d-axis current output resulted from transformation of a three-phase ac current into two-phase, an adder for adding a d-axis component of ac system voltage signal (Vsd) on the side of said rectifier, an output of said d-axis current control means, and a voltage-converted output of a q-axis current output resulted from said transformation into two-phase, reactive power control means for amplifying a difference between said specified value of the reactive power applied from said input means and a detected output from reactive power detective means, q-axis current control means for amplifying a difference between an output of said reactive power control means and said q-axis current output, an adder for adding a q-axis component of an ac system voltage signal (Vsq) on the side of said rectifier, an output of said q-axis current control means and a voltage-converted output of said d-axis current output, and a PWM control circuit for creating a gate pulse for said rectifier from output signals of both said adders, and wherein said second control means comprises active power control means for amplifying a difference between said specified value of the active power applied from said input means and a detected output from active power detective means, d-axis current control means for amplifying a difference between an output of said active power control means and a d-axis current output resulted from transformation of a three-phase ac current into two-phase, an adder for adding a d-axis component of the ac system voltage signal (Vsd) on the side of said inverter, an output of said d-axis current control means, and a voltage-converted output of a q-axis current output resulted from said transformation into two-phase, reactive power control means for amplifying a difference between said specified value of the reactive power applied from said input means and a detected output from reactive power detective means, q-axis current control means for amplifying a difference between an output of said reactive power control means and said q-axis current output, an adder for adding a q-axis component of the ac system voltage signal (Vsq), an output of said q-axis current control means and the voltage-converted output of said d-axis current output, and a PWM control circuit for creating a gate pulse for said inverter from output signals of both said adders.

Claim 18

A control equipment for a high voltage direct current (hvdc) transmission system having an equipment of self-commutated converter which comprises switching devices with a self-commutating function and is operated as a rectifier or an inverter, said control equipment comprising: first control means for controlling a first equipment of self-commutated converter, operated as said rectifier, in such a manner as to hold the dc voltage of a dc system in said high voltage dc transmission system and the reactive power on the input side of said first equipment of self-commutated converter at specified values, and second control means for controlling a second equipment of self-commutated converter, operated as said inverter, in such a manner as to hold the active power and the reactive power on the output side of said second equipment of self-commutated converter at specified values, wherein said first control means comprises dc voltage control means for amplifying a difference between said specified value of the dc voltage applied from input means and a detected output from dc voltage detective means, d-axis current control means for amplifying a difference between an output of said dc voltage control means and a d-axis current output resulted from transformation of a three-phase ac current into two-phase, an adder for adding a d-axis component of ac system voltage signal (Vsd) on the side of said rectifier, an output of said d-axis current control means, and a voltage-converted output of a q-axis current output resulted from said transformation into two-phase, reactive power control means for amplifying a difference between said specified value of the reactive power applied from said input means and a detected output from reactive power detective means, q-axis current control means for amplifying a difference between an output of said reactive power control means and said q-axis current output, an adder for adding a q-axis component of an ac system voltage signal (Vsq) on the side of said rectifier, an output of said q-axis current control means and a voltage-converted output of said d-axis current output, and a PWM control circuit for creating a gate pulse for said rectifier from output signals of both said adders, and wherein said second control means comprises active power control means for amplifying a difference between said specified value of the active power applied from said input means and a detected output from active power detective means, d-axis current control means for amplifying a difference between an output of said active power control means and a d-axis current output resulted from transformation of a three-phase ac current into two-phase, an adder for adding a d-axis component of the ac system voltage signal (Vsd) on the side of said inverter, an output of said d-axis current control means, and a voltage-converted output of a q-axis current output resulted from said transformation into two-phase, reactive power control means for amplifying a difference between said specified value of the reactive power applied from said input means and a detected output from reactive power detective means, q-axis current control means for amplifying a difference between an output of said reactive power control means and said q-axis current output, an adder for adding a q-axis component of the ac system voltage signal (Vsq), an output of said q-axis current control means and the voltage-converted output of said d-axis current output, and a PWM control circuit for creating a gate pulse for said inverter from output signals of both said adders.

Claim 19

The control equipment for a high voltage direct current transmission system of claim 1, wherein said first current control means for controlling said first equipment uses three-phase alternating current signals and three-phase alternating current voltage signals of an alternating current power and derives two-phase current signals transformed from said three-phase alternating current signals, and said second current control means for controlling said second equipment uses three-phase alternating current signals and three-phase alternating current voltage signals of an alternating current power and derives two-phase current signals transformed from said three-phase alternating current signals.

Claim 20

The control equipment for a high voltage direct current transmission system of claim 2, wherein said first current control means for controlling said first equipment uses three-phase alternating current signals and three-phase alternating current voltage signals of an alternating current power and derives two-phase current signals transformed from said three-phase alternating current signals, and said second current control means for controlling said second equipment uses three-phase alternating current signals and three-phase alternating current voltage signals of an alternating current power and derives two-phase current signals transformed from said three-phase alternating current signals.

Claim 21

The control equipment for a high voltage direct current transmission system of claim 3, wherein said first current control means for controlling said first equipment uses three-phase alternating current signals and three-phase alternating current voltage signals of an alternating current power and derives two-phase current signals transformed from said three-phase alternating current signals, and said second current control means for controlling said second equipment uses three-phase alternating current signals and three-phase alternating current voltage signals of an alternating current power and derives two-phase current signals transformed from said three-phase alternating current signals.

Claim 22

The control equipment for a high voltage direct current transmission system of claim 4, wherein said first current control means for controlling said first equipment uses three-phase alternating current signals and three-phase alternating current voltage signals of an alternating current power and derives two-phase current signals transformed from said three-phase alternating current signals, and said second current control means for controlling said second equipment uses three-phase alternating current signals and three-phase alternating current voltage signals of an alternating current power and derives two-phase current signals transformed from said three-phase alternating current signals.

Claim 23

The control equipment for a high voltage direct current transmission system of claim 5, wherein said first current control means for controlling said first equipment uses three-phase alternating current signals and three-phase alternating current voltage signals of an alternating current power and derives two-phase current signals transformed from said three-phase alternating current signals, and said second current control means for controlling said equipment of self-commutated converter uses three-phase alternating current signals and three-phase alternating current voltage signals of an alternating current power and derives two-phase current signals transformed from said three-phase alternating current signals.

Claim 24

The control equipment for a high voltage direct current transmission system of claim 6, wherein said first current control means for controlling said equipment of line-commutated converter uses three-phase alternating current signals and three-phase alternating current voltage signals of an alternating current power and derives two-phase current signals transformed from said three-phase alternating current signals, and said second current control means for controlling said equipment of self-commutated converter uses three-phase alternating current signals and three-phase alternating current voltage signals of an alternating current power and derives two-phase current signals transformed from said three-phase alternating current signals.

Claim 25

The control equipment for a high voltage direct current transmission system of claim 7, wherein said first current control means for controlling said equipment of line-commutated converter uses three-phase alternating current signals and three-phase alternating current voltage signals of an alternating current power and derives two-phase current signals transformed from said three-phase alternating current signals, and said second current control means for controlling said equipment of self-commutated converter uses three-phase alternating current signals and three-phase alternating current voltage signals of an alternating current power and derives two-phase current signals transformed from said three-phase alternating current signals.

Claim 26

The control equipment for a high voltage direct current transmission system of claim 8, wherein said first current control means for controlling said equipment of line-commutated converter uses three-phase alternating current signals and three-phase alternating current voltage signals of an alternating current power and derives two-phase current signals transformed from said three-phase alternating current signals, and said second current control means for controlling said equipment of self-commutated converter uses three-phase alternating current signals and three-phase alternating current voltage signals of an alternating current power and derives two-phase current signals transformed from said three-phase alternating current signals.