Adaptive automatic power capacitor for controlling controller a capacitor bank of a power distribution system

An adaptive power capacitor controller system for adjusting the reactive power of an electrical line by selectively applying a capacitor bank to the line, said controller system comprising

• a sensor for sensing at least one of a reactive current condition of the line and a voltage condition of the line,
• a switching element for coupling the capacitor bank to the line, said switching element establishing a first line state when the capacitor bank is connected to the line, and establishing a second line state when the capacitor bank is disconnected from the line, and
• control means associated with said switching element and with said sensor for selectively operating said switching element to connect the bank relative to the line, said control means including
• means for actuating said switching means for a selected succession of said first and second line states,
• means for determining a change in said reactive current of the line in response to at least one of said sensed reactive current and said sensed voltage between said first and second states during said selected succession,
• first threshold determination means for automatically determining a first threshold of at least one sensed line condition at which said control means operates said switching means to establish said first line condition in response to said change in reactive current, and
• second threshold determination means for automatically determining a second threshold of at least one sensed line condition at which said control means operates said switching means to establish said second line condition in response to said change in reactive current.

An adaptive power capacitor controller of the type for adjusting the reactive power of an AC electrical line, wherein the electrical line carries real power and reactive current having a phase angle relative to the line voltage, by selectively applying a capacitor bank to the line with a switching element, said capacitor controller comprising

• programmed control means for automatically actuating the switching element for coupling the capacitor bank selectively to the line to adjust said reactive power thereof, said control means including
• memory means for storing a program for operating the switching element to connect the capacitor bank to the line according to a predetermined sequence to determine changes in at least said reactive current of the line and said real power of the line,
• first determination means for automatically determining a change in said reactive current of the line during said predetermined sequence, said first determination means including means for generating a first value corresponding to a change in said reactive current,
• second determination means for automatically determining said change in said power of the line during said predetermined sequence, said second determination means including means for generating a second value corresponding to a negative change in said power, and
• adjustment means responsive to said first and second values for automatically compensating for said phase angle of said reactive current relative to the line voltage by a selected phase compensation value stored in said memory means and which value corresponds to at least one of said first and second values,
• whereby said first and second values indicate a reverse current condition in the line.

An adaptive power capacitor controller of the type for adjusting the reactive power of an AC electrical line, wherein the electrical line carries reactive current and a selected voltage, by selectively applying a capacitor bank to the line with a switching element, the switching element disconnecting the capacitor bank from the line when the line voltage exceeds a first selected voltage level, and connecting the bank to the line when the line voltage falls below a second selected voltage level, said capacitor controller comprising

• programmed control means for automatically actuating the switching element for coupling the capacitor bank selectively to the line to adjust said reactive power thereof, said control means including
• memory means for storing a program for operating the switching element to connect the capacitor bank relative to the line according to a predetermined sequence to determine changes in said reactive current of the line and said voltage of the line,
• first determination means for automatically determining said change in said reactive current of the line during said predetermined sequence, said first determination means including means for generating a first value when said change in said reactive current is about equal to zero,
• second determination means for automatically determining said change in said voltage of the line during said predetermined sequence, said second determination means including means for generating a second value corresponding to a change in said voltage, and
• predetermined parameter selection means, responsive to said first and second values and coupled to said memory means, for automatically establishing a first predetermined set point stored in said memory means as said first voltage level, and for automatically establishing a second predetermined set point stored in said memory means as said second voltage level,
• whereby said first and second values indicate a reverse power condition in the line.

An adaptive power capacitor controller of the type arranged for adjusting the reactive power of an AC electrical line carrying a selected voltage by selectively applying a capacitor bank to the line with a switching element, the switching element connecting the capacitor bank to the line in response to a selected reactive current condition in the line, said capacitor controller comprising

• programmed control means for automatically actuating the switching element for coupling the capacitor bank selectively to the line to adjust said reactive power thereof, said control means including
• memory means for storing a program therein, said stored program being adapted to operate the switching element to connect the capacitor bank relative to the line according to a predetermined sequence,
• first determination means for automatically determining at least said reactive current of the line during said predetermined sequence,
• parameter selection means coupled to said memory means and said first determination means for automatically determining a first set point corresponding to a first reactive current condition at which said control means operates the switching element to connect the capacitor bank to the line, and for automatically determining a second set point corresponding to a second reactive current condition at which said control means operates the switching element to disconnect the bank from the line, and
• adjustment means for automatically adjusting at least one of said set points when said reactive current condition in the line attains one of said reactive current conditions within a selected time of a previous reactive current condition, said previous reactive current condition corresponding to one of said first and second reactive current conditions.

An adaptive power capacitor controller of the type arranged for adjusting the reactive power of an AC electrical line carrying a selected voltage by selectively applying a capacitor bank to the line with a switching element, the switching element disconnecting the capacitor bank from the line when the line voltage exceeds a first selected voltage level, and connecting the bank to the line when the line voltage falls below a second selected voltage level, said capacitor controller comprising

• programmed control means for automatically actuating the switching element for coupling the capacitor bank selectively to the line to adjust said reactive power thereof, said control means including
• memory means for storing a program for operating the switching element to connect the capacitor bank to the line according to a predetermined sequence to determine at least a change in line voltage due to connection of the capacitor bank, said memory means including means for storing a first predetermined set point corresponding to said first voltage level and a second predetermined set point corresponding to said second voltage level, said first and second set points defining a selected voltage range,
• voltage selection means for automatically establishing a selected voltage level in response to at least said change in line voltage according to said predetermined sequence resident in said memory means, and
• inhibit means for automatically inhibiting said control means from operating the switching element to connect the bank relative to the line when a selected combination of said line voltage and said selected voltage level is outside of said selected voltage range.

A power capacitor controller system for adjusting the reactive power of an AC electrical line carrying reactive current and voltage by selectively applying reactive capacitance thereto from a capacitor bank, said controller system comprising

• current sensing means for sensing a reactive current line condition in the electrical line and for generating a current output signal indicative of sensed reactive current,
• voltage sensing means for sensing a voltage line condition in the electrical line and for generating a voltage output signal indicative of sensed voltage,
• switch means in circuit with said current sensing means and said voltage sensing means for selectively connecting the capacitor bank relative to the electrical line, and
• programmed control means in electrical communication with said switch means for automatically actuating said switch means to couple the capacitor bank selectively with the electrical line to adjust the reactive power thereof, said control means including
• memory means for storing at least one of said line conditions, and
• automatic parameter selection means coupled to said memory means for automatically establishing a first parameter determining connection of the capacitor bank to the electrical line and for automatically establishing a second parameter determining disconnection of the capacitor bank from the line in response to at least said reactive current output signal, said first and second parameters being established according to a programmed sequence resident in said memory means, whereby said controller system is adaptive and operates with programmed intelligence.

An adaptive power capacitor controller system for adjusting the reactive power of an AC electrical line carrying reactive current and voltage by selectively applying reactive capacitance thereto from a capacitor bank, said controller system comprising

• current sensing means for sensing a reactive current condition in the line,
• voltage sensing means for sensing a voltage condition in the line,
• switch means in circuit with said current sensing means and said voltage sensing means for selectively connecting and disconnecting the capacitor bank relative to the electrical line, and
• programmed control means in circuit with said switch means for automatically actuating said switch means to couple the capacitor bank selectively relative to the electrical line to adjust the reactive power thereof, said control means including
• memory means for storing at least one of said line conditions and for storing a program sequence that operates said switch means in a selected manner to connect or disconnect the capacitor bank relative to the line, and
• automatic parameter selection means coupled to said memory means for automatically establishing a first selected voltage level that determines the connection of the capacitor bank to the electrical line in response to one of said stored line conditions according to said program sequence.

An adaptive power capacitor controller system of the type arranged for adjusting the reactive power of a set of multi-phase electrical lines by selectively applying a capacitor bank thereto, the electrical lines carrying reactive current having a selected phase angle relative to the voltage of any of the electrical lines, said controller system comprising

• current sensing means for sensing a reactive current condition in a selected line and for generating a current output signal indicative of sensed reactive current,
• voltage sensing means for sensing a voltage condition in a selected line and for generating a voltage output signal indicative of sensed voltage,
• switch means in circuit with said current sensing means and said voltage sensing means for selectively connecting the capacitor bank relative to the electrical line, and
• programmed control means in circuit with said switch means and the line for automatically actuating said switch means selectively to couple the capacitor bank relative to the line to adjust the reactive power thereof, said control means including
• phase determination means for automatically determining the selected phase of said sensed reactive current relative to the sensed line voltage in response to at least one of said output signals.

An adaptive power capacitor controller system of the type arranged for adjusting the reactive power of a set of electrical lines by selectively applying a capacitor bank thereto, each electrical line carrying reactive current having a selected phase relative to a voltage in any of the lines, said controller system comprising

• current sensing means for sensing a reactive current condition in one of the lines and for generating a current output signal indicative of sensed reactive current of that line,
• voltage sensing means for sensing a voltage condition in one of the lines and for generating a voltage output signal indicative of sensed line voltage of that line,
• switch means in circuit with said current sensing means and said voltage sensing means for selectively connecting the capacitor bank relative to the electrical line, and
• control means in circuit with said switch means and the line for automatically actuating said switch means selectively to couple the capacitor bank relative to the line to adjust the reactive power thereof, said control means including
• memory means for storing at least one of said line conditions and for storing a program sequence that operates said switch means in a selected manner to couple selectively the capacitor bank relative to the line,
• first determination means for automatically determining a change in said reactive current of the line in response to said current output signal during said program sequence, said first determination means including means for generating a first value corresponding to said change in reactive current,
• second determination means for automatically determining a change in said voltage of the line in response to said voltage output signal during said program sequence, said second determination means including means for generating a second value corresponding to a negative change in said voltage,
• comparison means for comparing at least one of said first and second values with one of a predetermined voltage value stored in said memory means and a predetermined reactive current value stored in said memory means, each said one predetermined value having a selected compensation phase angle value associated therewith and wherein said comparison determines an appropriate phase angle value indicative of an amount by which said control means compensates for said phase angle, and
• adjustment means for automatically adjusting said phase angle of said sensed reactive current by said appropriate phase angle value,
• whereby said first and second values indicate a reverse current condition in the line.

An adaptive power capacitor controller system of the type arranged for adjusting the reactive power of an AC electrical line by selectively applying a capacitor bank relative to the line, the electrical line supporting a voltage and carrying reactive current, said controller system comprising

• current sensing means for sensing a reactive current condition in the line and for generating a current output signal indicative of sensed reactive current,
• voltage sensing means for sensing a voltage condition in the electrical line and for generating a voltage output signal indicative of sensed line voltage,
• switch means in circuit with said current sensing means and said voltage sensing means for selectively connecting the capacitor bank relative to the electrical line, and
• control means in circuit with said switch means and the line for automatically actuating said switch means selectively to couple the capacitor bank relative to the line to adjust the reactive power thereof, said control means including
• memory means for storing at least one of said line conditions and for storing a program sequence that operates said switch means in a manner to couple selectively the capacitor bank relative to the line,
• first determination means for automatically determining a change in said reactive current of the line in response to said current output signal during said program sequence, said first determination means including means for generating a first value when said change in said reactive current is about equal to zero, and
• second determination means for automatically determining a change in said voltage of the line in response to said voltage output signal during said program sequence, said second determination means including means for generating a second value corresponding to said change in said voltage,
• whereby said first and second values indicate a reverse power condition in the line.

An adaptive power capacitor controller system of the type arranged for adjusting the reactive power of an AC electrical line by selectively applying a capacitor bank relative to the line, the electrical line carrying reactive current and supporting a selected voltage, said controller system comprising

• current sensing means for sensing a reactive current condition in the line and for generating a current output signal indicative of sensed reactive current,
• voltage sensing means for sensing a voltage condition in the electrical line and for generating a voltage output signal indicative of sensed line voltage,
• switch means in circuit with said current sensing means and said voltage sensing means for selectively connecting the capacitor bank relative to the line, and
• programmed control means in circuit with said switch means and the line for automatically actuating said switch means selectively to couple the capacitor bank relative to the line to adjust the reactive power thereof, said control means including
• memory means for storing at least one of said line conditions and for storing a program sequence that operates said switch means in a selected manner to selectively couple the capacitor bank relative to the line,
• determination means coupled to said memory means for automatically determining a change in said reactive current of the line during said program sequence in response to at least one of said stored line conditions,
• parameter selection means for automatically establishing a first selected level determining connection of the capacitor bank relative to the electrical line in response to said change in reactive current and for automatically establishing a second selected level determining disconnection of the capacitor bank from the electrical line in response to said change in reactive current,
• time determination means for determining a first time interval between successive switching operations of said switch means, and
• comparison means for comparing said first time interval with a predetermined time interval stored in said memory means.

An adaptive power capacitor controller system of the type arranged for adjusting the reactive power of an AC electrical line by selectively applying a capacitor bank relative to the line, the electrical line carrying reactive current and supporting a selected voltage, said controller system comprising

• current sensing means for sensing a reactive current condition in the line and for generating a current output signal indicative of sensed reactive current,
• voltage sensing means for sensing a voltage condition in the electrical line and for generating a voltage output signal indicative of sensed line voltage,
• switch means in circuit with said current sensing means and said voltage sensing means for selectively connecting the capacitor bank relative to the electrical line, and
• control means in circuit with said switch means and the line for automatically actuating said switch means selectively to couple the capacitor bank relative to the line to adjust the reactive power thereof, said control means including
• memory means for storing at least one of said voltage condition and said reactive current condition, and for storing a program sequence that operates said switch means in a manner to selectively couple the capacitor bank relative to the line, and
• determination means coupled to said memory means for automatically determining a change in said line voltage of the line in response to at least said stored voltage condition during said program sequence,
• voltage selection means for automatically establishing a selected voltage value in response to at least said change in line voltage determined according to said program sequence, and
• inhibit means for automatically inhibiting said control means from operating said switch means when a combination of said line voltage and said voltage guard value is outside of a predetermined voltage range stored in said memory means.

A power capacitor controller system, comprising

• sensor means for sensing one or more electrical parameters of an electrical line,
• switching means coupled to a capacitor bank for connecting the bank to the line, the switching means establishing a first line condition when the capacitor bank is connected to the line and establishing a second line condition when the capacitor bank is disconnected from the line, wherein the capacitor bank has a selected size,
• means for automatically determining a first threshold value indicative of the capacitor bank connected to the line and a second threshold value indicative of the capacitor bank disconnected from the line in response to the electrical parameters sensed by the sensor means when the switching means attains the first line condition and when the switching means attains the second line condition, and
• size determination means for determining the size of the capacitor bank in response to the sensed electrical parameters in the line.

A method for adjusting the reactive power of a set of multi-phase electrical lines by selectively applying a capacitor bank thereto, the electrical lines carrying reactive current having a selected phase angle relative to the voltage of any of the electrical lines, the method comprising the steps of

• sensing a reactive current condition in a selected line and generating a current output signal indicative of sensed reactive current,
• sensing a voltage condition in a selected line and generating a voltage output signal indicative of sensed voltage,
• automatically and selectively connecting the capacitor bank relative to the electrical line, and
• automatically determining the selected phase of the sensed reactive current relative to the sensed line voltage in response to at least one of the output signals.

A method for adjusting the reactive power of a set of electrical lines by selectively applying a capacitor bank thereto, each electrical line carrying reactive current having a selected phase relative to a voltage in any of the lines, the method comprising the steps of

• sensing a reactive current condition in one of the lines and generating a current output signal indicative of sensed reactive current of that line,
• sensing a voltage condition in one of the lines and generating a voltage output signal indicative of sensed line voltage of that line,
• selectively connecting the capacitor bank relative to the electrical line to adjust the reactive power thereof,
• storing at least one of the line conditions and for storing a program sequence that couples selectively the capacitor bank relative to the line,
• automatically determining a change in the reactive current of the line in response to the current output signal during the program sequence, and generating a first value corresponding to the change in reactive current,
• automatically determining a change in the voltage of the line in response to the voltage output signal during the program sequence, and generating a second value corresponding to a negative change in the voltage,
• comparing at least one of the first and second values with one of a predetermined voltage value and a predetermined reactive current value, each one of the predetermined values having a selected compensation phase angle value associated therewith and wherein the comparison determines an appropriate phase angle value indicative of an amount by which the control means compensates for the phase angle, and
• automatically adjusting the phase angle of the sensed reactive current by the appropriate phase angle value,
• whereby the first and second values indicate a reverse current condition in the line.

A method for adjusting the reactive power of an AC electrical line by selectively applying a capacitor bank relative to the line, the electrical line supporting a voltage and carrying reactive current, the method comprising the steps of

• sensing a reactive current condition in the line and generating a current output signal indicative of sensed reactive current,
• sensing a voltage condition in the electrical line and generating a voltage output signal indicative of sensed line voltage,
• selectively connecting the capacitor bank relative to the electrical line, and to adjust the reactive power thereof,
• storing at least one of the line conditions and for storing a program sequence that couples selectively the capacitor bank relative to the line,
• automatically determining a change in the reactive current of the line in response to the current output signal during the program sequence, and generating a first value when the change in the reactive current is about equal to zero, and
• automatically determining a change in the voltage of the line in response to the voltage output signal during the program sequence, and generating a second value corresponding to the change in the voltage,
• whereby the first and second values indicate a reverse power condition in the line.

A method for adjusting the reactive power of an AC electrical line by selectively applying a capacitor bank relative to the line, the electrical line carrying reactive current and supporting a selected voltage, the method comprising the steps of

• sensing a reactive current condition in the line and generating a current output signal indicative of sensed reactive current,
• sensing a voltage condition in the electrical line and generating a voltage output signal indicative of sensed line voltage,
• selectively connecting the capacitor bank relative to the line to adjust the reactive power thereof,
• storing at least one of the line conditions, a program sequence that selectively couples the capacitor bank relative to the line, and a selected time interval,
• automatically determining a change in the reactive current of the line during the program sequence in response to at least one of the stored line conditions,
• automatically establishing a first selected level determining connection of the capacitor bank relative to the electrical line in response to the change in reactive current and automatically establishing a second selected level determining disconnection of the capacitor bank from the electrical line in response to the change in reactive current,
• determining a first time interval between successive switching operations, and
• comparing the first time interval with the predetermined time interval.

A method for adjusting the reactive power of an AC electrical line by selectively applying a capacitor bank relative to the line, the electrical line carrying reactive current and supporting a selected voltage, the method comprising the steps of

• sensing a reactive current condition in the line and generating a current output signal indicative of sensed reactive current,
• sensing a voltage condition in the electrical line and generating a voltage output signal indicative of sensed line voltage,
• selectively connecting the capacitor bank relative to the electrical line to adjust the reactive power thereof,
• storing at least one of the voltage condition and the reactive current condition, and storing a program sequence that selectively couples the capacitor bank relative to the line,
• automatically determining a change in the line voltage of the line in response to at least the stored voltage condition during the program sequence,
• automatically establishing a selected voltage value in response to at least the change in line voltage determined according to the program sequence, and
• automatically inhibiting connection of the capacitor bank relative to the line when a combination of the line voltage and the voltage value is outside of a predetermined voltage range stored in the memory means.