CN104934984B - Low-voltage deloading self-adaption setting method based on PV curve - Google Patents

Abstract

The embodiment of the invention provides a low-voltage deloading self-adaption setting method based on a PV curve. The method comprises the steps of drawing the PV curve of a transformer substation under network topology of a power system, respectively determining the last low-voltage deloading setting value and a deloading voltage recovery target value according to a critical voltage stabilization point and a maximum voltage point of the PV curve, uniformly distributing setting values of deloading turns between the last low-voltage deloading setting value and the deloading voltage recovery target value according to the set deloading turns, and calculating deloading quantities of the deloading turns according to the setting values of the deloading turns. According to the method, the setting values and the deloading quantities of the low-voltage deloading turns are determined in a self-adaption manner by the PV curve solved by utilizing real-time substation domain information. Provisions in DL755-2001 Guide on Security and Stability for Power System and Guidelines on Power System Voltage and Reactive Power Techniques are taken into account in a process of determining the setting values of the turns in the self-adaption manner; and the validity and the correctness of selection of the setting values in the scheme are ensured.

Description

A kind of low-voltage load sheding self-adaptive sites method based on PV curves

Technical field

Subtract the present invention relates to electric power system stability control technical field, more particularly to a kind of low pressure based on PV curves It is downloaded from adapting to the low-voltage load sheding self-adaptive sites method that setting method is based on PV curves.

Background technology

With the interconnection and expansion of power network, electric network composition is increasingly sophisticated.Environmental factor, the restriction of economic factor also make electric power The ruuning situation of system is more nearly maximum conditions.Most common situation is, as the power plant of power supply away from the most heavy city of load City, load side bus is usually in idle nervous state, once no-power vacancy occurs in system, the voltage of associated bus will be with Decline, be this may result in when serious Voltage Instability collapse accident generation.In recent years, foreign countries there occurs multiple Voltage Instability thing Therefore, be all system loading it is overweight, in the case that reactive-load compensation is not enough, by a certain line fault and then cause system voltage unstability Collapse, has ultimately caused large-area power-cuts.

Voltage Instability and collapse of voltage event occur rapidly, and are difficult to be found by staff in accident formation stages.It is low Press off-load as the important component of power system safety and stability three lines of defence, be to prevent Voltage Collapses in Power Systems, protect Card system voltage stablizes maximally effective measure.But, low-voltage load sheding as a newer technology, there is presently no system Setting method.Application of the low-voltage load sheding in practical power systems is still in the starting stage, studies the engineering philosophy of low-voltage load sheding And setting program, effectively played a role in power network for low-voltage load sheding device most important.

Therefore, it is a problem demanding prompt solution to develop a kind of setting method of effective low-voltage load sheding.

The content of the invention

PV curves are based on The embodiment provides a kind of low-voltage load sheding self-adaptive sites method based on PV curves Low-voltage load sheding self-adaptive sites method, to realize developing a kind of setting method of effective low-voltage load sheding.

To achieve these goals, this invention takes following technical scheme.

A kind of low-voltage load sheding self-adaptive sites method based on PV curves, including：

PV curve of the transformer station under current power grid topology is drawn, the voltage stabilization according to the PV curves faces Boundary's point and voltage peak determine that the setting valve and off-load voltage of the last wheel low-voltage load sheding recover desired value respectively；

Off-load round sum according to setting, mesh is recovered in the setting valve and off-load voltage of the last wheel low-voltage load sheding The setting valve of each off-load round is evenly distributed between scale value；

Setting valve according to each off-load round calculates the off-load amount of each off-load round.

Methods described also includes：

In the transformer station of configuration low-voltage load sheding device, repaiied at set time intervals according to electrical power system wide-area information Positive network topology structure, PV of the transformer station under current power grid topology is drawn according to revised network topology structure Curve.

Described voltage stability critical point and voltage peak according to the PV curves determines the last wheel low pressure respectively The setting valve and off-load voltage of off-load recover desired value, including：

Determine the minimum critical point A points of PV curves, A point voltages U_AIt is the minimum stabilization working voltage of the node, calculates U '_Last =1.05 × U_AIf substation bus bar voltage minimum specified in guiding rules of power system safety and stability is M1, the last wheel is low Press the setting valve U of off-load_LastTake M1 and 1.05 × U_AMiddle higher value, be in PV curves correspondence ordinate

Determine the peak point B points of PV curves, B point voltages U_BIt is the node voltage peak, calculates U '_Goal=0.92 × U_B, If the minimum magnitude of voltage that recovers of transformer station that power system voltage and var fire protection technology specify is M2, off-load voltage recovers mesh Scale value U_GoalTake M2 and 0.92 × U_BIn higher value, PV curves correspondence ordinate be

The described off-load round sum according to setting, in the setting valve and off-load voltage of the last wheel low-voltage load sheding The setting valve of each off-load round is evenly distributed between recovery desired value, including：

Off-load round sum N is determined to off-load required precision according to transformer station, in the last wheel setting valve of low-voltage load sheding U_LastRecover desired value U with voltage_GoalIn evenly distribute the setting valve U of each off-load round_Act1、U_Act2、...、U_ActN, each subtracts Carry the setting valve U of round_Act1、U_Act2、...、U_ActNIt is respectively in PV curves correspondence ordinate

The setting valve of each off-load round described in described basis calculates the off-load amount of each off-load round, including：

Each wheel off-load amount, respectively Δ P are calculated according to PV curves₁、ΔP₂、...、ΔP_N；

The actuation time of each off-load round is set according to specific system performance and part throttle characteristics, then the low pressure of each round The self-adaptive sites scheme of off-load is as follows：

The technical scheme provided by embodiments of the invention described above can be seen that the embodiment of the present invention by using station domain reality When the PV curves that solve of information, it is adaptive to should determine that each round setting valve of low-voltage load sheding and each round off-load amount.It is true in self adaptation During fixed each round setting valve, it is also contemplated that《DL755-2001 guiding rules of power system safety and stability》With《Power system electricity Pressure and var fire protection technology》In regulation, it is ensured that this programme setting valve selection validity and correctness.

The additional aspect of the present invention and advantage will be set forth in part in the description, and these will become from the following description Obtain substantially, or recognized by practice of the invention.

Brief description of the drawings

Technical scheme in order to illustrate more clearly the embodiments of the present invention, below will be to that will use needed for embodiment description Accompanying drawing be briefly described, it should be apparent that, drawings in the following description are only some embodiments of the present invention, for this For the those of ordinary skill of field, without having to pay creative labor, other can also be obtained according to these accompanying drawings Accompanying drawing.

Fig. 1 is a kind for the treatment of of low-voltage load sheding self-adaptive sites method based on PV curves that the embodiment of the present invention one is provided Flow chart；

Fig. 2 is the node system model schematics of a kind of CEPRI 36 that the embodiment of the present invention two is provided；

Fig. 3 is a kind of PV curve maps of load bus B29 that the embodiment of the present invention two is provided.

Specific embodiment

Embodiments of the present invention are described below in detail, the example of the implementation method is shown in the drawings, wherein ad initio Same or similar element or element with same or like function are represented to same or similar label eventually.Below by ginseng The implementation method for examining Description of Drawings is exemplary, is only used for explaining the present invention, and is not construed as limiting the claims.

Those skilled in the art of the present technique are appreciated that unless expressly stated, singulative " " used herein, " one It is individual ", " described " and " being somebody's turn to do " may also comprise plural form.It is to be further understood that what is used in specification of the invention arranges Diction " including " refer to the presence of the feature, integer, step, operation, element and/or component, but it is not excluded that in the presence of or addition One or more other features, integer, step, operation, element, component and/or their group.It should be understood that when we claim unit Part is " connected " or during " coupled " to another element, and it can be directly connected or coupled to other elements, or can also exist Intermediary element.Additionally, " connection " used herein or " coupling " can include wireless connection or coupling.Wording used herein "and/or" includes one or more associated any cells for listing item and all combines.

Those skilled in the art of the present technique are appreciated that unless otherwise defined, all terms used herein (including technology art Language and scientific terminology) have with art of the present invention in those of ordinary skill general understanding identical meaning.Should also Understand, those terms defined in such as general dictionary should be understood that the meaning having with the context of prior art The consistent meaning of justice, and unless defined as here, will not be with idealizing or excessively formal implication be explained.

For ease of the understanding to the embodiment of the present invention, done by taking several specific embodiments as an example further below in conjunction with accompanying drawing Explanation, and each embodiment does not constitute the restriction to the embodiment of the present invention.

Embodiment one

The operation principle of low-voltage load sheding is the stabilization for exchanging system voltage for a small amount of cutting load, generally uses and subtracts by wheel The mode of load, each round is made up of operation voltage, actuation time and epicycle off-load amount.

The embodiment of the present invention proposes a kind of based on PV (the curve of the quantitative Relationship between bus power and bus voltage, transport interface trend and node voltage relation) it is bent The low-voltage load sheding self-adaptive sites method of line.Main the characteristics of is the PV curves solved by domain real time information of standing, self adaptation Determine each round setting valve and each round off-load amount of low-voltage load sheding.It is adaptive should determine that each round setting valve during, also Consider《DL755-2001 guiding rules of power system safety and stability》With《Power system voltage and var fire protection technology》In Regulation, it is ensured that the validity and correctness of the setting valve selection in the embodiment of the present invention.

The embodiment of the present invention is intended to overcome the setting parameter of current low-voltage load sheding, more by engineering staff's experience, is gathered by examination It is often constant for a long time after method determines final off-load scheme, and off-load scheme determines, it is impossible to the situation of adaptive system change in topology. Existing power grid construction is rapid, power system topology often change, it is necessary to it is a kind of can with system topological change change it is low Pressure off-load setting program.

To reach above-mentioned purpose, the low-voltage load sheding self-adaptive sites method based on PV curves that the embodiment of the present invention is proposed Process chart as described in Figure 1, comprises the following steps：

Step S110：In the transformer station of configuration low-voltage load sheding device, net is corrected according to electrical power system wide-area information in real time Network topology.

Step S120：Draw PV curve of this transformer station under power system network topology.

Step S130：Determine the critical point A points of PV curves.A point voltages U_AIt is the minimum stabilization working voltage of the node, most end One wheel off-load setting valve cannot be below U_A, 5% nargin is stayed, take U_Last=1.05 × U_AIt is the last wheel setting valve of low-voltage load sheding. In this step, U_LastIn addition to the PV curve critical point A points of this transformer station are considered, it is also contemplated that《DL755-2001 power trains System safety and stability directive/guide》Middle regulation.Regulation load-center substation or to be connected to important load customer substation busbar voltage low in directive/guide In 0.75pu time-dependent system is more than 1s.U_LastTake 0.75pu and 1.05 × U_AMiddle higher value, in PV curves correspondence ordinate For

Step S140：Determine PV curve voltage peak B points.Voltage is in 0.9U_BBelow all in tolerance interval, guard Take U_Goal=0.92 × U_BFor off-load voltage recovers desired value.In this step, U_GoalExcept the PV peak of curves for considering this transformer station Outside point B points, it is also contemplated that《Power system voltage and var fire protection technology》Middle regulation.After specifying that accident occurs in directive/guide The recovery voltage of 220KV transformer stations must not be less than 0.9p.u..U_GoalTake 0.9p.u. and 0.92 × U_BIn higher value, it is bent in PV Line corresponds to ordinate

Step S150：Determine that (according to engineering experience, N leads to off-load round sum N to off-load required precision according to this transformer station Often less than 5), in the last wheel setting valve of low-voltage load sheding U_LastRecover desired value U with voltage_GoalIn evenly distribute each off-load wheel Secondary setting valve U_Act1、U_Act2、...、U_ActN, the setting valve U of each off-load round_Act1、U_Act2、...、U_ActNIn PV curves correspondence Ordinate is respectively

Step S160：Each wheel off-load amount, respectively Δ P are calculated according to PV curves₁、ΔP₂、...、ΔP_N；

Step S170：For the setting of actuation time (i.e. off-load time delay), particular system can be common to the system therefore Barrier is emulated, and shorter time delay is taken if the system is quick voltage unstability accident-prone area.Additionally, asynchronous motor load is more Node should take shorter time delay.

Step S180：Low-voltage load sheding self-adaptive sites scheme.

The low-voltage load sheding self-adaptive sites scheme of table 1

Wherein, basic wheel refers to the round of quick acting in automatic low-voltage load sheding device, and special opinion refers to long delay, subtracts again Carry round.Set it is special wheel predominantly prevent substantially wheel off-load after voltage suspended at low pressure, voltage restoration result it is undesirable.

Embodiment two

In the node systems of the CEPRI 36 topology schematic diagram shown in Fig. 2, one has 9 load buses, with load bus Low-voltage load sheding self-adaptive sites scheme application process of the explanation based on PV curves, comprises the following steps that as a example by B29：

Step one：By electrical power system wide-area information, in good time update the system topology, it is assumed that current system topological such as Fig. 2 institutes Show；

Step 2：Draw PV curve of this transformer station under system architecture topology as shown in Figure 3；

Step 3：Determine PV curve critical point A points.U_A=0.66p.u. then 1.05 × U_A=0.693p.u., 0.693p.u. It is less than《DL755-2001 guiding rules of power system safety and stability》Specified in 0.75p.u., therefore U_Last=0.75p.u..

Step 4：Determine PV peak of curves point B points.U_B=0.99p.u. then 0.92 × U_B=0.911p.u., 0.911p.u. It is more than《Power system voltage and var fire protection technology》Specified in 0.9p.u., therefore U_Goal=0.911p.u..

Step 5：Off-load round sum N=4 is determined, in the last wheel setting valve of low-voltage load sheding U_Last=0.75p.u. and Voltage recovers desired value U_GoalBasic round setting valve U is evenly distributed in=0.911p.u._Act1、U_Act2、U_Act3、U_Act4。

U_Act4=U_Last=0.75p.u.

Step 6：Each wheel off-load amount, respectively Δ P are calculated according to PV₁、ΔP₂、ΔP₃、ΔP₄；

Step 7：The setting of off-load time delay.To this particular system can the failure common to the system emulate, the system It is quick voltage unstability accident-prone area, t takes shorter time delay, t=0.3s.

Step 8：Load bus B29 low-voltage load sheding setting programs are as follows：

The load bus B29 low-voltage load sheding setting programs of table 2

In sum, the embodiment of the present invention is by using the PV curves that solve of station domain real time information, it is adaptive should determine that it is low Pressure each round setting valve of off-load and each round off-load amount.It is adaptive should determine that each round setting valve during, it is also contemplated that 《DL755-2001 guiding rules of power system safety and stability》With《Power system voltage and var fire protection technology》In regulation, protect The validity and correctness of the setting valve selection of this programme are demonstrate,proved.

The embodiment of the present invention overcomes the setting parameter of current low-voltage load sheding, more by engineering staff's experience, by trial and error procedure It is determined that often constant for a long time after final off-load scheme, and the determination of off-load scheme, it is impossible to the situation of adaptive system change in topology.This Scheme, anterior round off-load amount is big, and rear portion round off-load amount is small, is conducive to the fast quick-recovery of voltage.Existing power grid construction is rapid, electricity Force system topology often changes, it is necessary to a kind of low-voltage load sheding setting program that can change with system topological and change.

One of ordinary skill in the art will appreciate that：Accompanying drawing is the schematic diagram of one embodiment, module in accompanying drawing or Flow is not necessarily implemented necessary to the present invention.

As seen through the above description of the embodiments, those skilled in the art can be understood that the present invention can Realized by the mode of software plus required general hardware platform.Based on such understanding, technical scheme essence On the part that is contributed to prior art in other words can be embodied in the form of software product, the computer software product Can store in storage medium, such as ROM/RAM, magnetic disc, CD, including some instructions are used to so that a computer equipment (can be personal computer, server, or network equipment etc.) performs some of each embodiment of the invention or embodiment Method described in part.

Each embodiment in this specification is described by the way of progressive, identical similar portion between each embodiment Divide mutually referring to what each embodiment was stressed is the difference with other embodiment.Especially for device or For system embodiment, because it is substantially similar to embodiment of the method, so describing fairly simple, related part is referring to method The part explanation of embodiment.Apparatus and system embodiment described above is only schematical, wherein the conduct Separating component explanation unit can be or may not be it is physically separate, the part shown as unit can be or Person may not be physical location, you can with positioned at a place, or can also be distributed on multiple NEs.Can be with root Some or all of module therein is factually selected the need for border to realize the purpose of this embodiment scheme.Ordinary skill Personnel are without creative efforts, you can to understand and implement.

The above, the only present invention preferably specific embodiment, but protection scope of the present invention is not limited thereto, Any one skilled in the art the invention discloses technical scope in, the change or replacement that can be readily occurred in, Should all be included within the scope of the present invention.Therefore, protection scope of the present invention should be with scope of the claims It is defined.

Claims (4)

1. a kind of low-voltage load sheding self-adaptive sites method based on PV curves, it is characterised in that including：

PV curve of the transformer station under current power grid topology is drawn, according to the voltage stability critical point of the PV curves The setting valve and off-load voltage for determining the last wheel low-voltage load sheding respectively with voltage peak recover desired value；

Off-load round sum according to setting, desired value is recovered in the setting valve and off-load voltage of the last wheel low-voltage load sheding Between evenly distribute the setting valve of each off-load round；

Setting valve according to each off-load round calculates each off-load round off-load amount；

Described voltage stability critical point and voltage peak according to the PV curves determines the last wheel low-voltage load sheding respectively Setting valve and off-load voltage recover desired value, including：

Determine the minimum critical point A points of PV curves, voltage U_AIt is the minimum stabilization working voltage of A points, calculates U '_Last=1.05 × U_A, If substation bus bar voltage minimum specified in guiding rules of power system safety and stability is M1, the last takes turns adjusting for low-voltage load sheding Value U_LastTake M1 and 1.05 × U_AMiddle higher value, be in PV curves correspondence ordinate

Determine the peak point B points of PV curves, voltage U_BIt is B point voltage peaks, calculates U '_Goal=0.92 × U_BIf, power system The minimum magnitude of voltage that recovers of transformer station that voltage and var fire protection technology specify is M2, and off-load voltage recovers desired value U_GoalTake M2 and 0.92 × U_BIn higher value, PV curves correspondence ordinate be

2. the low-voltage load sheding self-adaptive sites method based on PV curves according to claim 1, it is characterised in that the side Method also includes：

In the transformer station of configuration low-voltage load sheding device, net is corrected according to electrical power system wide-area information at set time intervals Network topological structure, draws PV of the transformer station under current power grid topology bent according to revised network topology structure Line.

3. the low-voltage load sheding self-adaptive sites method based on PV curves according to claim 1 and 2, it is characterised in that institute The off-load round sum according to setting stated, desired value is recovered in the setting valve and off-load voltage of the last wheel low-voltage load sheding Between evenly distribute the setting valve of each off-load round, including：

Off-load round sum N is determined to off-load required precision according to transformer station, in the last wheel setting valve of low-voltage load sheding U_LastAnd electricity Pressure recovers desired value U_GoalIn evenly distribute the setting valve U of each off-load round_Act1、U_Act2、...、U_ActN, each off-load round Setting valve U_Act1、U_Act2、...、U_ActNIt is respectively in PV curves correspondence ordinate

$\begin{array}{c}{U}_{Act1}=\frac{N-1}{N}{U}_{Goal}+\frac{1}{N}{U}_{Last}\\ U_{Act2}=\frac{N-2}{N}{U}_{Goal}+\frac{2}{N}{U}_{Last}\\ .\\ .\\ .\\ U_{ActN}=U_{Last}\end{array}.$

4. the low-voltage load sheding self-adaptive sites method based on PV curves according to claim 3, it is characterised in that described Setting valve according to each off-load round calculates the off-load amount of each off-load round, including：

Each wheel off-load amount, respectively Δ P are calculated according to PV curves₁、ΔP₂、...、ΔP_N；

$\begin{array}{c}{\mathrm{\ΔP}}_1=P_{U_{Act1}}-P_{U_{Goal}}\\ {\mathrm{\ΔP}}_2=P_{U_{Act2}}-P_{U_{Act1}}\\ .\\ .\\ .\\ {\mathrm{\ΔP}}_N=P_{U_{ActN}}-P_{U_{ActN-1}}\end{array}$

According to specific system performance and part throttle characteristics, the actuation time of each off-load round is set, then the low pressure of each round subtracts The self-adaptive sites scheme of load is as follows：