Inductorless symmetrical component sequence analyzer

Claim 2

A symmetrical component sequence analyzer for providing output signals proportional to the positive or negative sequence symmetrical component of a three-phase power source, comprising: a. first, second and third input means for connection to a three-phase power source; b. an output terminal; c. first and second resistance elements connected in series between said first input means and said output terminal; d. a first capacitance element connected between said second input means and said output terminal; e. a third resistance element connected between said second input means and the connection of said first and second resistance element; and f. a second capacitance element connected between said third input means and the connection of said first and second resistance element; g. whereby said output signals proportional to the symmetrical component of the three-phase power source are developed between said output terminal and said third input means.

Claim 3

A symmetrical component sequence analyzer according to claim 1, wherein the resistance of said second resistance element equals ##EQU11## the reactance of said first capacitance element equals ##EQU12## and the reactance of said second capacitance element equals ##EQU13## where R 1 equals the value of said first resistance element, R 3 equals the value of said third resistance element, and K equals a selected constant.

Claim 4

A symmetrical component sequence analyzer according to claim 2 further including control means connected to said output terminals for providing a control signal when said output signals reach a predetermined value, and switching means connected to receive said control signals from said control means, said switching means for controlling the connection of a load to the three-phase power source in response to said control signals.

Claim 5

A symmetrical component sequence analyzer according to claim 1 further including an output load impedance connected between said output terminal and said third input means.

Claim 6

A symmetrical component sequence analyzer for providing output signals proportional to the positive or negative sequence symmetrical component of a three-phase power source, comprising: a. first, second and third input means for connection to the three phases of a three-phase power source, and fourth input means for connection to the neutral point of a three-phase power source; b. first and second ouput terminals, said second terminal connected to said fourth input means; c. first and second resistance elements connected in series between said first input means and said first output terminal; d. first and second capacitance means connected in series between said third input means and said first output terminal; e. a third resistance element and a third capacitance element connected in parallel with each other between said second input means and said first output terminal; f. a fourth capacitance element connected between said fourth input means and the connection of said first and second resistance elements; and g. a fourth resistance element connected between said fourth input means and the connection of said first and second capacitance elements.

Claim 7

A symmetrical component sequence analyzer for providing output signals proportional to the positive or negative sequence symmetrical component of a three-phase power source, comprising: a. first, second and third input means for connection to the three phases of a three-phase power source, and fourth input means for connection to the neutral point of a three-phase power source; b. first and second ouput terminals, said second terminal connected to said fourth input means; c. first and second resistance elements connected in series between said first input means and said first output terminal; d. first and second capacitance means connected in series between said third input means and said first output terminal; e. a third resistance element and a third capacitance element connected in parallel with each other between said second input means and said first output terminal; f. a fourth capacitance element connected between said fourth input means and the connection of said first and second resistance elements; and g. a fourth resistance element connected between said fourth input means and the connection of said first and second capacitance elements.

Claim 8

A symmetrical component sequence analyzer according to claim 5, wherein the value of said third resistance element equals 5.46(R 1 +R 2 ), the value of said fourth resistance element equals ##EQU14## the reactance of said second capacitance element equals R 1 +R 2 -X 1 , the reactance of said third capacitance element equals 5.46(R 1 +R 2 ), and the reactance of said fourth capacitance element equals ##EQU15## where R 1 equals the value of said first resistance element, R 2 equals the value of said second resistance element, and X 1 equals the reactance of said first capacitance element.

Claim 9

A symmetrical component sequence analyzer according to claim 6 further including control means connected to said output terminals for providing a control signal when said output signals reach a predetermined value, and switching means connected to receive said control signals from said control means, said switching means for controlling the connection of a load to the three-phase power source in response to said control signals.

Claim 10

A symmetrical component sequence analyzer according to claim 5 further including an output load impedance connected to said output terminals.