CN102778634B - Distribution network voltage fluctuation positioning method and device - Google Patents

Abstract

The invention discloses a distribution network voltage fluctuation positioning method and a distribution network voltage fluctuation positioning device. A voltage fluctuation generating direction positioning algorithm is adopted, and the voltage fluctuation direction indicator variable is calculated from voltage and current waveform sampling values of the head end of the distribution network circuit, wherein the direction indicator variable fx is +1, 0 or -1; when fx is equal to +1, the voltage fluctuation comes from the lower part of the circuit; when fx is equal to -1, the voltage fluctuation comes from the upper part of the circuit; and when fx is equal to 0, effective information of voltage fluctuation positioning cannot be obtained. According to the distribution network voltage fluctuation positioning device and the distribution network voltage fluctuation positioning method, the voltage fluctuation source direction can be judged according to the voltage and current waveform sampling values of the head end of the distribution network circuit, the fluctuation types are indicated, and the voltage fluctuation generating position is deduced according to directional signals of all the monitoring points.

Description

Distribution voltage fluctuation localization method and locating device

Technical field

The present invention relates to a kind of voltage fluctuation localization method, particularly a kind of distribution voltage fluctuation localization method and locating device.

Background technology

Along with the deep development of electricity market, power quality problem more and more receives Utilities Electric Co. and user's concern.In numerous electrical energy power quality disturbances, distribution voltage fluctuation be incidence higher, cause damage one of distribution network electric energy quality problem more serious.Can accurately monitor distribution voltage wave phenomenon at present, for analysis disturbing cause, assessment disturbance harm provide substantially first section.But detect merely voltage characteristic amount and can not determine voltage fluctuation interference source, cannot determine which bar circuit voltage fluctuation source is positioned at, and this just causes electric network fault accurately to locate, and cannot overhaul in time and definite responsibility.

Summary of the invention

The object of the invention is to overcome the deficiencies in the prior art part, and a kind of distribution voltage fluctuation localization method that can accurately locate distribution voltage fluctuation source is provided.

The present invention is also to provide a kind of distribution voltage fluctuation locating device that can accurately locate distribution voltage fluctuation source.

A distribution voltage fluctuation localization method, is characterized in that: (1) obtains voltage, current waveform sampled value from distribution line head end, constructing virtual three-phase values, and it is specially, and establish line voltage waveform and meet function suc as formula shown in (1),

$\left\{\begin{array}{c}{u}_a\left(t\right)=\sqrt{2}U\sin \left(\mathrm{\ωt}\right)\\ u_b\left(t\right)=\sqrt{2}U\sin (\mathrm{\ωt}-\frac{2}{3}\mathrm{\π})\\ u_c\left(t\right)=\sqrt{2}U\sin (\mathrm{\ωt}+\frac{2}{3}\mathrm{\π})\end{array}\right.---\left(1\right)$

When three-phase voltage is symmetrical, have

$\left\{\begin{array}{c}{u}_b\left(t\right)=\sqrt{2}U\sin \left(\mathrm{\ω}(t-\frac{T}{3})\right)=u_a(t-\frac{T}{3})\\ u_c\left(t\right)=\sqrt{2}U\sin \left(\mathrm{\ω}(t+\frac{T}{3})\right)=u_a(t+\frac{T}{3})\end{array}\right.---\left(2\right)$

Thereby can be from residue two phase signals b (t) and the c (t) of single voltage or current signal a (t) constructing virtual,

$\left\{\begin{array}{c}b\left(t\right)=a(t-\frac{T}{3})\\ c\left(t\right)=a(t+\frac{T}{3})\end{array}\right.$

(2) get respectively each phase voltage, electric current structure three-phase composite signal, obtain following 6 groups of combinations: { u _a(t), u _b-a(t), u _c-a(t) }, { u _a-b(t), u _b(t), u _c-b(t) }, { u _a-c(t), u _b-c(t), u _c(t) }, { i _a(t), i _b-a(t), i _c-a(t) }, { i _a-b(t), i _b(t), i _c-b(t) }, { i _a-c(t), i _b-c(t), i _c(t) }, add original three-phase signal { u _a(t), u _b(t), u _c(t) }, { i _a(t), i _b(t), i _c(t) }, totally 8 groups of three-phase electric quantity signals carry out xy0 coordinate conversion;

(3), in each sampling instant, from 8 groups of three-phase electric quantity signals, by formula (4) to (6), calculate respectively 8 phasors wherein N is every cycle sampling number, and k is sampled point sequence number, $\stackrel{\·}{Y}={\left[\begin{array}{ccc}{\stackrel{\·}{y}}_a& {\stackrel{\·}{y}}_b& {\stackrel{\·}{y}}_c\end{array}\right]}^T$ Represent one of 8 groups of three-phase electric quantity signals,

$\left[\begin{array}{c}{d}_x\left(k\right)\\ d_y\left(k\right)\\ d_0\left(k\right)\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos \left(\frac{2\mathrm{k\π}}{N}\right)& \cos (\frac{2\mathrm{k\π}}{N}-\frac{2}{3}\mathrm{\π})& \cos (\frac{2\mathrm{k\π}}{N}+\frac{2}{3}\mathrm{\π})\\ -\sin \left(\frac{2\mathrm{k\π}}{N}\right)& -\sin (\frac{2\mathrm{k\π}}{N}-\frac{2}{3}\mathrm{\π})& -\sin (\frac{2\mathrm{k\π}}{N}+\frac{2}{3}\mathrm{\π})\\ \frac{1}{2}& \frac{1}{2}& \frac{1}{2}\end{array}\right]\·\left[\begin{array}{c}{y}_a\left(k\right)\\ y_b\left(k\right)\\ y_c\left(k\right)\end{array}\right]---\left(4\right)$

(4) calculating of voltage fluctuation direction signal fx: calculate 8 phasors after, respectively to each phasor note as △ D (k) >0.1U _b, meter is just changing 1 time, during and if only if continuous counter 3 times, and output waveform judgment variable lt=1; As △ D (k) <-0.1U _b, the negative change of meter 1 time, during and if only if continuous counter 3 times, output waveform judgment variable lt=-1.Thereby calculate 8 signal waveform judgment variable lt ₁to lt ₈.Number corresponding electric quantity signal type as follows: 1 actual three-phase voltage signal, the three-phase virtual voltage signal that 2A phase voltage generates, the three-phase virtual voltage signal that 3B phase voltage generates, the three-phase virtual voltage signal that 4C phase voltage generates, the three-phase virtual current signal that the three-phase virtual current signal 8C phase current that the three-phase virtual current signal 7B phase current that 5 actual three-phase current signal 6A phase currents generate generates generates.

It is positive dirction that the electric current of take during calculated direction signal fx flows into circuit, and fx=1 represents that voltage fluctuation is positioned at circuit positive dirction, and fx=-1 represents that voltage fluctuation is positioned at circuit in the other direction, and fx=0 represents not monitor obvious voltage fluctuation.Direction signal fx=-lt ₁* lt ₅.

(5) judgement of voltage fluctuation position: and if only if when there is fx=1 circuit both sides, and judgement voltage fluctuation occurs on this circuit.

(6) calculating of voltage fluctuation type signal lx: Rule of judgment is lt when lx is 1 ₁≠ 0, lt ₁=1: illustrate that three-phase voltage rises sharply, lt ₁=-1: three-phase voltage rapid drawdown is described; When lx is 2, Rule of judgment is lt ₁=lt ₃=lt ₄=0, lt ₂≠ 0, lt ₂=1:A phase voltage rises sharply, lt ₂the rapid drawdown of=-1:A phase voltage; When lx is 3, Rule of judgment is lt ₁=lt ₂=lt ₄=0, lt ₃≠ 0, lt ₃=1:A phase voltage rises sharply, lt ₃the rapid drawdown of=-1:A phase voltage; When lx is 4, Rule of judgment is lt ₁=lt ₂=lt ₃=0, lt ₄≠ 0, lt ₄=1:A phase voltage rises sharply, lt ₄the rapid drawdown of=-1:A phase voltage.

A kind of distribution voltage fluctuation locating device, its structural feature is: comprise filtering and signal acquisition module, with 1. virtual three-phase electricity signal configuration algorithm, 2. wave form varies evaluation algorithm, 3. the calculating of direction signal fx and type signal lx, 4. the dsp processor of distribution voltage fluctuation type and location algorithm function, with system parameter setting, system equipment monitoring running state, and realize man-machine interaction, the arm processor of report upload function, ethernet communication module, display device, described filtering and signal acquisition module are based on digital signal processing unit, filtering and signal acquisition module are connected to obtain voltage from distribution line head end with distribution line head end, current waveform sampled value, the output terminal of filtering and signal acquisition module is connected with dsp processor, dsp processor output terminal is connected with arm processor, arm processor is connected with ethernet communication module and display device respectively, ethernet communication module realizes uploading of system data.

Filtering and signal acquisition module are based on digital signal processing unit, to realize the high speed acquisition of online 12 channel voltages, current signal, the main algorithm of dsp processor completion system, arm processor is mainly responsible for the functions such as system management, demonstration, communication, comprise system parameter setting, system equipment monitoring running state, and realize man-machine interaction, report upload.

In sum, the present invention's following advantage compared to existing technology:

Distribution voltage fluctuation localization method of the present invention and locating device, can be from distribution line head end voltage, current waveform sampled value judgement voltage fluctuation source direction, point out the type of fluctuation, and according to the generation position of the direction signal derivation voltage fluctuation of whole monitoring points.

Accompanying drawing explanation

Fig. 1 is the process flow diagram of distribution voltage fluctuation localization method of the present invention.

Fig. 2 is the theory diagram of distribution voltage fluctuation locating device of the present invention.

Embodiment

Below in conjunction with embodiment, the present invention is described in more detail.

Embodiment 1

A kind of distribution voltage fluctuation localization method as shown in Figure 1, (1) a kind of distribution voltage fluctuation localization method, it is characterized in that: (1) obtains voltage, current waveform sampled value from distribution line head end, constructing virtual three-phase values, it is specially, if line voltage waveform meets function suc as formula shown in (1)

$\left\{\begin{array}{c}{u}_a\left(t\right)=\sqrt{2}U\sin \left(\mathrm{\&omega;t}\right)\\ u_b\left(t\right)=\sqrt{2}U\sin (\mathrm{\&omega;t}-\frac{2}{3}\mathrm{\&pi;})\\ u_c\left(t\right)=\sqrt{2}U\sin (\mathrm{\&omega;t}+\frac{2}{3}\mathrm{\&pi;})\end{array}\right.---\left(1\right)$

When three-phase voltage is symmetrical, have

$\left\{\begin{array}{c}{u}_b\left(t\right)=\sqrt{2}U\sin \left(\mathrm{\&omega;}(t-\frac{T}{3})\right)=u_a(t-\frac{T}{3})\\ u_c\left(t\right)=\sqrt{2}U\sin \left(\mathrm{\&omega;}(t+\frac{T}{3})\right)=u_a(t+\frac{T}{3})\end{array}\right.---\left(2\right)$

Thereby can be from single voltage or current signal u _a(t) the residue two phase signals u of constructing virtual _b-aand u (t) _c-a(t),

$\left\{\begin{array}{c}b\left(t\right)=a(t-\frac{T}{3})\\ c\left(t\right)=a(t+\frac{T}{3})\end{array}\right.$

(2) get respectively each phase voltage, electric current structure three-phase composite signal, obtain following 6 groups of combinations: { u _a(t), u _b-a(t), u _c-a(t) }, { u _a-b(t), u _b(t), u _c-b(t) }, { u _a-c(t), u _b-c(t), u _c(t) }, { i _a(t), i _b-a(t), i _c-a(t) }, { i _a-b(t), i _b(t), i _c-b(t) }, { i _a-c(t), i _b-c(t), i _c(t) }, add original three-phase signal { u _a(t), u _b(t), u _c(t) }, { i _a(t), i _b(t), i _c(t) }, totally 8 groups of three-phase electric quantity signals carry out xy0 coordinate conversion;

(3), in each sampling instant, from 8 groups of three-phase electric quantity signals, by formula (4) to (6), calculate respectively 8 phasors wherein N is every cycle sampling number, and k is sampled point sequence number, $\stackrel{\&CenterDot;}{Y}={\left[\begin{array}{ccc}{\stackrel{\&CenterDot;}{y}}_a& {\stackrel{\&CenterDot;}{y}}_b& {\stackrel{\&CenterDot;}{y}}_c\end{array}\right]}^T$ Represent one of 8 groups of three-phase electric quantity signals,

$\left[\begin{array}{c}{d}_x\left(k\right)\\ d_y\left(k\right)\\ d_0\left(k\right)\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos \left(\frac{2\mathrm{k\&pi;}}{N}\right)& \cos (\frac{2\mathrm{k\&pi;}}{N}-\frac{2}{3}\mathrm{\&pi;})& \cos (\frac{2\mathrm{k\&pi;}}{N}+\frac{2}{3}\mathrm{\&pi;})\\ -\sin \left(\frac{2\mathrm{k\&pi;}}{N}\right)& -\sin (\frac{2\mathrm{k\&pi;}}{N}-\frac{2}{3}\mathrm{\&pi;})& -\sin (\frac{2\mathrm{k\&pi;}}{N}+\frac{2}{3}\mathrm{\&pi;})\\ \frac{1}{2}& \frac{1}{2}& \frac{1}{2}\end{array}\right]\&CenterDot;\left[\begin{array}{c}{y}_a\left(k\right)\\ y_b\left(k\right)\\ y_c\left(k\right)\end{array}\right]---\left(4\right)$

(4) calculating of voltage fluctuation direction signal fx: calculate 8 phasors after, respectively to each phasor note as △ D (k) >0.1U _b, meter is just changing 1 time, during and if only if continuous counter 3 times, and output waveform judgment variable lt=1; As △ D (k) <-0.1U _b, the negative change of meter 1 time, during and if only if continuous counter 3 times, output waveform judgment variable lt=-1, thereby calculate 8 signal waveform judgment variable lt ₁to lt ₈number corresponding electric quantity signal type as follows: 1 actual three-phase voltage signal, the three-phase virtual voltage signal that 2A phase voltage generates, the three-phase virtual voltage signal that 3B phase voltage generates, the three-phase virtual voltage signal that 4C phase voltage generates, the three-phase virtual current signal that the three-phase virtual current signal 8C phase current that the three-phase virtual current signal 7B phase current that 5 actual three-phase current signal 6A phase currents generate generates generates

It is positive dirction that the electric current of take during calculated direction signal fx flows into circuit, and fx=1 represents that voltage fluctuation is positioned at circuit positive dirction, and fx=-1 represents that voltage fluctuation is positioned at circuit in the other direction, and fx=0 represents not monitor obvious voltage fluctuation, direction signal fx=-lt ₁* lt ₅;

(5) judgement of voltage fluctuation position: and if only if when there is fx=1 circuit both sides, and judgement voltage fluctuation occurs on this circuit;

(6) calculating of voltage fluctuation type signal lx: Rule of judgment is lt when lx is 1 ₁≠ 0, lt ₁=1: illustrate that three-phase voltage rises sharply, lt ₁=-1: three-phase voltage rapid drawdown is described; When lx is 2, Rule of judgment is lt ₁=lt ₃=lt ₄=0, lt ₂≠ 0, lt ₂=1:A phase voltage rises sharply, lt ₂the rapid drawdown of=-1:A phase voltage; When lx is 3, Rule of judgment is lt ₁=lt ₂=lt ₄=0, lt ₃≠ 0, lt ₃=1:A phase voltage rises sharply, lt ₃the rapid drawdown of=-1:A phase voltage; When lx is 4, Rule of judgment is lt ₁=lt ₂=lt ₃=0, lt ₄≠ 0, lt ₄=1:A phase voltage rises sharply, lt ₄the rapid drawdown of=-1:A phase voltage.

It is same as the prior art that the present embodiment is not stated part.

Embodiment 2

A kind of distribution voltage fluctuation locating device, comprise filtering and signal acquisition module, with 1. virtual three-phase electricity signal configuration algorithm, 2. wave form varies evaluation algorithm, 3. the calculating of direction signal fx and type signal lx, 4. the dsp processor of distribution voltage fluctuation type and location algorithm function, with system parameter setting, system equipment monitoring running state, and realize man-machine interaction, the arm processor of report upload function, ethernet communication module, display device, described filtering and signal acquisition module are based on digital signal processing unit, filtering and signal acquisition module are connected to obtain voltage from distribution line head end with distribution line head end, current waveform sampled value, the output terminal of filtering and signal acquisition module is connected with dsp processor, dsp processor output terminal is connected with arm processor, arm processor is connected with ethernet communication module and display device respectively, ethernet communication module realizes uploading of system data.

It is identical with embodiment 1 that the present embodiment is not stated part.

Claims (1)

1. a distribution voltage fluctuation localization method, is characterized in that: (1) obtains voltage, current waveform sampled value from distribution line head end, constructing virtual three-phase values, and it is specially, and establish line voltage waveform and meet function suc as formula shown in (1),

$\left\{\begin{array}{c}{u}_a\left(t\right)=\sqrt{2}U\sin \left(\mathrm{\&omega;t}\right)\\ u_b\left(t\right)=\sqrt{2}U\sin (\mathrm{\&omega;t}-\frac{2}{3}\mathrm{\&pi;})\\ u_c\left(t\right)=\sqrt{2}U\sin (\mathrm{\&omega;t}+\frac{2}{3}\mathrm{\&pi;})\end{array}\right.---\left(1\right)$

When three-phase voltage is symmetrical, have

$\left\{\begin{array}{c}{u}_b\left(t\right)=\sqrt{2}U\sin \left(\mathrm{\&omega;}(t-\frac{T}{3})\right)=u_a(t-\frac{T}{3})\\ u_{}\left(t\right)=\sqrt{2}U\sin \left(\mathrm{\&omega;}(t+\frac{T}{3})\right)=u_a(t+\frac{T}{3})\end{array}\right.---\left(2\right)$

Thereby can be from residue two phase signals b (t) and the c (t) of single voltage or current signal a (t) constructing virtual,

$\left\{\begin{array}{c}b\left(t\right)=a(t-\frac{T}{3})\\ c\left(t\right)=a(t+\frac{T}{3})\end{array}\right.$

(2) get respectively each phase voltage, electric current structure three-phase composite signal, obtain following 6 groups of combinations: { u _a(t), u _b-a(t), u _c-a(t) }, { u _a-b(t), u _b(t), u _c-b(t) }, { u _a-c(t), u _b-c(t), u _c(t) }, { i _a(t), i _b-a(t), i _c-a(t) }, { i _a-b(t), i _b(t), i _c-b(t) }, { i _a-c(t), i _b-c(t), i _c(t) }, add original three-phase signal { u _a(t), u _b(t), u _c(t) }, { i _a(t), i _b(t), i _c(t) }, totally 8 groups of three-phase electric quantity signals carry out xy0 coordinate conversion;

(3), in each sampling instant, from 8 groups of three-phase electric quantity signals, by formula (4) to (6), calculate respectively 8 phasors wherein N is every cycle sampling number, and k is sampled point sequence number, represent one of 8 groups of three-phase electric quantity signals,

$\left[\begin{array}{c}{d}_x\left(k\right)\\ d_y\left(k\right)\\ d_0\left(k\right)\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos \left(\frac{2\mathrm{k\&pi;}}{N}\right)& \cos (\frac{2\mathrm{k\&pi;}}{N}-\frac{2}{3}\mathrm{\&pi;})& \cos (\frac{2\mathrm{k\&pi;}}{N}+\frac{2}{3}\mathrm{\&pi;})\\ -\sin \left(\frac{2\mathrm{k\&pi;}}{N}\right)& -\sin (\frac{2\mathrm{k\&pi;}}{N}-\frac{2}{3}\mathrm{\&pi;})& -\sin (\frac{2\mathrm{k\&pi;}}{N}+\frac{2}{3}\mathrm{\&pi;})\\ \frac{1}{2}& \frac{1}{2}& \frac{1}{2}\end{array}\right]\&CenterDot;\left[\begin{array}{c}{y}_a\left(k\right)\\ y_b\left(k\right)\\ y_c\left(k\right)\end{array}\right]---\left(4\right)$

(4) calculating of voltage fluctuation direction signal fx: calculate 8 phasors after, respectively to each phasor note as Δ D (k) > 0.1U _b, meter is just changing 1 time, during and if only if continuous counter 3 times, and output waveform judgment variable 1t=1; As Δ D (k) <-0.1U _b, the negative change of meter 1 time, during and if only if continuous counter 3 times, output waveform judgment variable 1t=-1, thereby calculate 8 signal waveform judgment variable 1t ₁to 1t ₈number corresponding electric quantity signal type as follows: 1 actual three-phase voltage signal, the three-phase virtual voltage signal that 2A phase voltage generates, the three-phase virtual voltage signal that 3B phase voltage generates, the three-phase virtual voltage signal that 4C phase voltage generates, the three-phase virtual current signal that the three-phase virtual current signal 8C phase current that the three-phase virtual current signal 7B phase current that 5 actual three-phase current signal 6A phase currents generate generates generates

It is positive dirction that the electric current of take during calculated direction signal fx flows into circuit, and fx=1 represents that voltage fluctuation is positioned at circuit positive dirction, and fx=-1 represents that voltage fluctuation is positioned at circuit in the other direction, and fx=0 represents not monitor obvious voltage fluctuation, direction signal fx=-1t ₁* 1t ₅;

(5) judgement of voltage fluctuation position: and if only if when there is fx=1 circuit both sides, and judgement voltage fluctuation occurs on this circuit;

(6) calculating of voltage fluctuation type signal 1x: Rule of judgment is 1t when 1x is 1 ₁≠ 0,1t ₁=1: illustrate that three-phase voltage rises sharply, 1t ₁=-1: three-phase voltage rapid drawdown is described; When 1x is 2, Rule of judgment is 1t ₁=1t ₃=1t ₄=0,1t ₂≠ 0,1t ₂=1:A phase voltage rises sharply, 1t ₂the rapid drawdown of=-1:A phase voltage; When 1x is 3, Rule of judgment is 1t ₁=1t ₂=1t ₄=0,1t ₃≠ 0,1t ₃=1:A phase voltage rises sharply, 1t ₃the rapid drawdown of=-1:A phase voltage; When 1x is 4, Rule of judgment is 1t ₁=1t ₂=1t ₃=0,1t ₄≠ 0,1t ₄=1:A phase voltage rises sharply, 1t ₄the rapid drawdown of=-1:A phase voltage.