US5384696A — Active power line conditioner with fundamental ne…

Claim 1

Independent Claim 99 words

A method of operating an active power line conditioner, said active power line conditioner being of the type which includes a series inverter coupled to a load, said series inverter including a series inverter controller receiving a voltage signal with a negative sequence fundamental voltage component, said method comprising the steps of: identifying said negative sequence fundamental voltage component through a synchronous transformation of said voltage signal; inverting said negative sequence fundamental voltage component to produce a series filter reference signal; and applying said series filter reference signal to said series inverter to cancel said negative sequence fundamental voltage.

Claim 2

Independent Claim 99 words

A method of operating an active power line conditioner, said active power line conditioner being of the type which includes a series inverter coupled to a load, said series inverter including a series inverter controller receiving a voltage signal with a negative sequence fundamental voltage component, said method comprising the steps of: identifying said negative sequence fundamental voltage component through a synchronous transformation of said voltage signal; inverting said negative sequence fundamental voltage component to produce a series filter reference signal; and applying said series filter reference signal to said series inverter to cancel said negative sequence fundamental voltage.

Claim 3

Dependent Claim 22 words

The method of claim 1 wherein said identifying step includes the step of transforming said voltage signal into direct and quadrature signals.

Claim 4

Dependent Claim 80 words

The method of claim 1 wherein said identifying step relies upon a phase-locked loop performing the following steps: producing an instantaneous vector sum for first and second components of said voltage signal; establishing a plurality of relative phase values Θ between said first and second components of said voltage signal; selecting one of said relative phase values Θ to form a selected phase value; and defining a sin -Θ and a cos -Θ value corresponding to said selected phase value.

Claim 5

Dependent Claim 73 words

The method of claim 1 further comprising the steps of: generating a series filter feedforward signal corresponding to fundamental components of a load current of said load; combining said series filter feedforward signal and said series filter reference signal to produce a series filter compensation signal; and conveying said series filter compensation signal to said series inverter to cancel said negative sequence fundamental voltage and to generate sinusoidal input currents for said load.

Claim 6

Independent Claim 100 words

A method of operating an active power line conditioner, said active power line conditioner being of the type which includes a parallel inverter coupled to a load, said parallel inverter including a parallel inverter controller receiving a current signal with a negative sequence fundamental current component, said method comprising the steps of: identifying said negative sequence fundamental current component with a synchronous transformation of said current signal; inverting said negative sequence fundamental current component to produce a parallel filter reference signal; and applying said parallel filter reference signal to said parallel inverter to eliminate said negative sequence fundamental current component.

Claim 7

Independent Claim 100 words

A method of operating an active power line conditioner, said active power line conditioner being of the type which includes a parallel inverter coupled to a load, said parallel inverter including a parallel inverter controller receiving a current signal with a negative sequence fundamental current component, said method comprising the steps of: identifying said negative sequence fundamental current component with a synchronous transformation of said current signal; inverting said negative sequence fundamental current component to produce a parallel filter reference signal; and applying said parallel filter reference signal to said parallel inverter to eliminate said negative sequence fundamental current component.

Claim 8

Dependent Claim 22 words

The method of claim 5 wherein said identifying step includes the step of transforming said current signal into direct and quadrature signals.

Claim 9

Dependent Claim 82 words

The method of claim 5 wherein said identifying step relies upon a phase-locked loop performing the following steps: producing an instantaneous vector sum for first and second serial inverter input voltage signals; establishing a plurality of relative phase values Θ between said first and second serial inverter input voltage signals; selecting one of said relative phase values Θ to form a selected phase value; and means for defining a sin -Θ and a cos -Θ value corresponding to said selected phase value.

Claim 10

Dependent Claim 69 words

The method of claim 5 further comprising the steps of: producing a parallel filter signal corresponding to harmonic ripple components of a load current for said load; combining said parallel filter signal and said parallel filter reference signal to produce a parallel filter compensation signal; and conveying said parallel filter compensation signal to said parallel inverter to generate sinusoidal voltages for said load and to balance said current signal.

Claim 11

Dependent Claim 202 words

An active power line conditioner comprising: a series inverter coupled to an energy input source; a parallel inverter coupled to a load, said parallel inverter receiving a current signal with a negative sequence fundamental current component; an energy storage element electrically connected between said series inverter and said parallel inverter; a series filter controller coupled to said series inverter and receiving a voltage signal with a negative sequence fundamental voltage component, said series filter controller including means for identifying said negative sequence fundamental voltage component with a synchronous transformation of said voltage signal, and means for comparing said negative sequence fundamental voltage component with a desired negative sequence fundamental value to produce a series filter reference signal which is applied to said series inverter to cancel said negative sequence fundamental voltage; and a parallel filter controller coupled to said parallel inverter, said parallel filter controller including means for identifying said negative sequence fundamental current component with a synchronous transformation of said current signal, and means for comparing said negative sequence fundamental current component with a desired negative sequence fundamental value to produce a parallel filter reference signal which is applied to said parallel inverter to eliminate said negative sequence fundamental current component.

Claim 12

Dependent Claim 202 words

An active power line conditioner comprising: a series inverter coupled to an energy input source; a parallel inverter coupled to a load, said parallel inverter receiving a current signal with a negative sequence fundamental current component; an energy storage element electrically connected between said series inverter and said parallel inverter; a series filter controller coupled to said series inverter and receiving a voltage signal with a negative sequence fundamental voltage component, said series filter controller including means for identifying said negative sequence fundamental voltage component with a synchronous transformation of said voltage signal, and means for comparing said negative sequence fundamental voltage component with a desired negative sequence fundamental value to produce a series filter reference signal which is applied to said series inverter to cancel said negative sequence fundamental voltage; and a parallel filter controller coupled to said parallel inverter, said parallel filter controller including means for identifying said negative sequence fundamental current component with a synchronous transformation of said current signal, and means for comparing said negative sequence fundamental current component with a desired negative sequence fundamental value to produce a parallel filter reference signal which is applied to said parallel inverter to eliminate said negative sequence fundamental current component.

Claim 13

Dependent Claim 133 words

The apparatus of claim 9 wherein said series filter controller includes: a 3-to-2 phase transformer which receives said voltage signal and resolves it into a single voltage vector which rotates at a constant frequency with respect to a stationary reference frame with a v ds axis and a v qs axis; a stationary-to-rotating transformer which receives said voltage vector and generates a reference frame with a v d axis and a v q axis which rotates at a voltage vector constant frequency, said stationary-to-rotating transformer converting said voltage vector into v dn and v qn signals corresponding to said negative sequence fundamental input voltage; and means for comparing said v d and v q signals with a desired negative sequence fundamental input voltage value to produce corresponding v dn* and v qn* signals.

Claim 14

Dependent Claim 65 words

The apparatus of claim 10 further comprising a rotating-to-stationary transformer to perform the inverse operation of said stationary-to-rotating transformer on said v dn* and v qn* signals to generate v dn*' and v qn*' signals; and a 2-to-3 phase transformer to perform the inverse operation of said 3-to-2 phase transformer on said v dn*' and v qn*' signals, thereby generating said series filter reference signal.

Claim 15

Dependent Claim 133 words

The apparatus of claim 9 wherein said parallel filter controller includes: a 3-to-2 phase transformer which receives said current signal and resolves it into a single current vector which rotates at a constant frequency with respect to a stationary reference frame with an i ds axis and an i qs axis; a stationary-to-rotating transformer which receives said current vector and generates a reference frame with an i d axis and an i q axis which rotates at a current vector constant frequency, said stationary-to-rotating transformer converting said current vector into i dn and i qn signals corresponding to said negative sequence fundamental current signal; and means for comparing said i d and i q signals with a desired negative sequence fundamental current signal value to produce corresponding i dn* and i qn* signals.

Claim 16

Dependent Claim 65 words

The apparatus of claim 12 further comprising a rotating-to-stationary transformer to perform the inverse operation of said stationary-to-rotating transformer on said i dn* and i qn* signals to generate i dn*' and i qn*' signals; and a 2-to-3 phase transformer to perform the inverse operation of said 3-to-2 phase transformer on said i dn*' and i qn*' signals, thereby generating said parallel filter reference signal.

Claim 17

Dependent Claim 116 words

The apparatus of claim 9 further including a vector phase-locked loop coupled to said series filter controller and said parallel filter controller, said vector phase-locked loop comprising: a 3-to-2 phase transformer for continuously producing an instantaneous vector sum for first and second serial inverter input voltage signals; a phase detector, coupled to said 3-to-2 phase transformer, for sequentially establishing, from said first and second serial inverter input voltage signals, a plurality of relative phase values Θ between said voltage signals; a timing mechanism for selecting one of said relative phase values Θ to form a selected phase value; and means for defining a sin -Θ and a cos -Θ value corresponding to said selected phase value.

Claim 18

Dependent Claim 71 words

The apparatus of claim 9 further comprising: means for generating a series filter feedforward signal corresponding to fundamental components of a load current of said load; and means for combining said series filter feedforward signal and said series filter reference signal to produce a series filter compensation signal which is applied to said series inverter to cancel said negative sequence fundamental voltage and to generate sinusoidal input currents for said load.

Claim 19

Dependent Claim 66 words

The apparatus of claim 9 further comprising: means for producing a parallel filter signal corresponding to harmonic ripple components of a load current for said load; means for combining said parallel filter signal and said parallel filter reference signal to produce a parallel filter compensation signal which is applied to said parallel inverter to generate sinusoidal voltages for said load and to balance said current signal.

Claim 20

Independent Claim 104 words

A method of testing an active power line conditioner which provides a load current to a load, said active power line conditioner being of the type which includes a series inverter coupled to a parallel inverter through an energy storage link, said method comprising the steps of: producing a parallel filter reference signal corresponding to a preselected negative sequence fundamental current signal component; generating a series filter reference signal corresponding to a preselected negative sequence fundamental voltage signal component; and assessing the effect of said preselected negative sequence fundamental current signal component and said preselected negative sequence fundamental voltage signal component on said load.

Claim 21

Independent Claim 104 words

A method of testing an active power line conditioner which provides a load current to a load, said active power line conditioner being of the type which includes a series inverter coupled to a parallel inverter through an energy storage link, said method comprising the steps of: producing a parallel filter reference signal corresponding to a preselected negative sequence fundamental current signal component; generating a series filter reference signal corresponding to a preselected negative sequence fundamental voltage signal component; and assessing the effect of said preselected negative sequence fundamental current signal component and said preselected negative sequence fundamental voltage signal component on said load.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1998-01-23	1998-07-25	1999-01-24	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2002-01-23	2002-07-25	2003-01-24	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2006-01-23	2006-07-25	2007-01-24	$7700.00	Window Closed / Lapsed

Active power line conditioner with fundamental negative sequence compensation

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