CN108964105A - The DC voltage control method and DC voltage controller of both-end flexible direct current occasion - Google Patents
The DC voltage control method and DC voltage controller of both-end flexible direct current occasion Download PDFInfo
- Publication number
- CN108964105A CN108964105A CN201810015275.0A CN201810015275A CN108964105A CN 108964105 A CN108964105 A CN 108964105A CN 201810015275 A CN201810015275 A CN 201810015275A CN 108964105 A CN108964105 A CN 108964105A
- Authority
- CN
- China
- Prior art keywords
- voltage
- preset
- deviation
- formula
- voltage deviation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
- H02J2003/365—Reducing harmonics or oscillations in HVDC
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The present invention provides a kind of DC voltage control method of both-end flexible direct current occasion and DC voltage controllers, this method comprises: getting the power deviation between the voltage deviation between the direct voltage reference value of sending end and the dc voltage measurements of sending end, the value and power reference of sending end and the power measurement values of sending end；Tradeoff coefficient is calculated according to voltage deviation and preset voltage deviation factor；Voltage deviation is modified according to preset DC voltage offset value, error is calculated according to tradeoff coefficient, revised voltage deviation and power deviation by preset first formula；Error input PI controller is obtained into d shaft current；Preset first formula are as follows: δ=K Δ u '+(1-K) Δ p, Δ u ' is revised voltage deviation, and Δ p is power deviation, and K is tradeoff coefficient.The present invention carries out pattern switching (i.e. the calculating process of error) by mathematical function, before being placed in PI link due to pattern switching, greatly shortens the time of pattern switching, the out-of-limit level of DC voltage during reducing failure.
Description
Technical field
The present invention relates to the voltage margin control field of multiterminal flexible direct current more particularly to a kind of DC voltage stability sides
Method and DC voltage stability device.
Background technique
With the continuous improvement of the permeability of flexible DC transmission, when AC network breaks down, based on the soft of MMC
Property direct current transportation should play its and control flexible advantage, keep not off-grid continuous operation as far as possible, and provide branch for power system restoration
Support, that is, have the ability of fault traversing.Fault traversing technology is directly related to the unfailing performance and peace of flexible HVDC transmission system
Full performance.Currently, this is based primarily upon whole in terms of existing control fault method has focused largely on single-ended converter station Fault Control
There is reliable communication for analysis premise between stream station and Inverter Station, i.e. guarantee non-faulting end uses constant DC voltage control, in turn
Guarantee the stabilization of whole system DC voltage.
The voltage margin control for being suitable for multiterminal flexible direct current is applied to both-end flexible direct current occasion by the prior art, really
Determine power end after guarantor's receiving end failure to detect voltage deviation and be switched to constant DC voltage control.The control of DC voltage nargin
Basic principle is as shown in Figure 1.Wherein, udcIt is sending end DC voltage measured value and active power measured value with p；UdrefLAnd UdrefH
It is the high and low deviation limit value of sending end converter station determined under DC voltage mode respectively；PrefSending end is determined under direct current active power
Value and power reference；idcrefL、idcrefPAnd idcrefHIt is PI respectively1、PI2And PI3Output.
The control logic of current reference value are as follows:
idref=max [idcrefL,min(idcrefH,idcrefP)]
In Fig. 1, determine DC voltage and determine the switching of active power to be by idcrefL、idcrefPAnd idcrefHSize relation
It determines.
Due to the effect of PI controlling unit, determine active power converter station has when operating normally:
From the above equation, we can see that being at this time to determine active power controller.
As DC voltage udcRise to UdrefHWhen, idcrefHIt is gradually reduced, idcrefPBe gradually increasing, through after a period of time it
I afterwardsdcrefH< idcrefPWhen, constant DC voltage control after controller switching.Process is similar when DC voltage declines.As it can be seen that in electricity
When pressure is more than system limiting design value, handover control system does not carry out stable DC voltage to controller at once, causes direct current system electric
The voltage overshoot of pressure is excessive.
Summary of the invention
The embodiment of the invention provides a kind of DC voltage control method of both-end flexible direct current occasion and direct current are voltage-controlled
Device processed is solved when voltage is more than system limiting design value, and handover control system does not carry out stable DC electricity to controller at once
Pressure, the technical problem for causing the voltage overshoot of direct current system voltage excessive.
The present invention provides a kind of DC voltage control methods of both-end flexible direct current occasion, comprising:
Get voltage deviation between the direct voltage reference value of sending end and the dc voltage measurements of sending end, sending end
Value and power reference and sending end power measurement values between power deviation；
Tradeoff coefficient is calculated according to the voltage deviation and preset voltage deviation factor；
The voltage deviation is modified according to preset DC voltage offset value, by preset first formula according to institute
It states tradeoff coefficient, the revised voltage deviation and the power deviation and calculates error；
Error input PI controller is obtained into d shaft current；
Preset first formula are as follows:
δ=K Δ u '+(1-K) Δ p
In formula, Δ u ' is revised voltage deviation, and Δ p is power deviation, and K is tradeoff coefficient.
It is preferably, described that tradeoff coefficient is calculated according to the voltage deviation and preset voltage deviation factor specifically:
Tradeoff coefficient is calculated according to preset voltage deviation and the voltage deviation coefficient by preset second formula；
Preset second formula are as follows:
K=λ1Δu2
In formula, λ1For preset voltage deviation factor, Δ u is voltage deviation.
It is preferably, described that the voltage deviation is modified according to preset DC voltage offset value specifically:
The voltage deviation is modified according to preset DC voltage offset value by preset third formula；
The preset third formula are as follows:
Δ u '=Δ u-sign (Δ u) λ2
In formula, (Δ u) is the sign function of Δ u, λ to sign2For preset DC voltage offset value.
Preferably, the present invention also provides a kind of DC voltage controllers, comprising: the first comparison module, second compare mould
Block, coefficient selection module, mode switch module and PI controller；
First comparison module is connect with the coefficient selection module；
First comparison module, second comparison module are connect with the mode switch module respectively；
The coefficient selection module connection is connect with the mode switch module；
The mode switch module is connect with the PI controller；
First comparison module is used to get the dc voltage measurements of direct voltage reference value and sending end, and right
The direct voltage reference value and the dc voltage measurements of sending end obtain voltage deviation as difference；
Second comparison module is used to get the power measurement values of value and power reference and sending end, and to the power
The power measurement values of reference value and sending end obtain power deviation as difference；
The coefficient selection module is used to calculate tradeoff coefficient according to the voltage deviation and preset voltage deviation factor；
The mode switch module is led to for being modified according to preset DC voltage offset value to the voltage deviation
It crosses preset first formula and error is calculated according to the tradeoff coefficient, the revised voltage deviation and the power deviation；
The PI controller is for carrying out the error d shaft current is calculated；
Preset first formula are as follows:
δ=K Δ u '+(1-K) Δ p
In formula, Δ u ' is revised voltage deviation, and Δ p is power deviation, and K is tradeoff coefficient.
Preferably, the coefficient selection module be also used to by preset second formula according to preset voltage deviation with it is described
Voltage deviation coefficient calculates tradeoff coefficient；
Preset second formula are as follows:
K=λ1Δu2
In formula, λ1For preset voltage deviation factor, Δ u is voltage deviation.
Preferably, the mode switch module specifically includes:
First computing unit, for inclined to the voltage according to preset DC voltage offset value by preset third formula
Difference is modified；
The preset third formula are as follows:
Δ u '=Δ u-sign (Δ u) λ2
In formula, (Δ u) is the sign function of Δ u, λ to sign2For preset DC voltage offset value；
Second computing unit, for inclined according to the tradeoff coefficient, the revised voltage by preset first formula
The poor and described power deviation calculates error；
Preset first formula are as follows:
δ=K Δ u '+(1-K) Δ p
In formula, Δ u ' is revised voltage deviation, and Δ p is power deviation, and K is tradeoff coefficient.
As can be seen from the above technical solutions, the embodiment of the present invention has the advantage that
The present invention provides a kind of DC voltage control method of both-end flexible direct current occasion and DC voltage controller,
This method comprises: getting the voltage deviation between the direct voltage reference value of sending end and the dc voltage measurements of sending end, sending
Power deviation between the value and power reference at end and the power measurement values of sending end；According to voltage deviation and preset voltage deviation system
Number calculates tradeoff coefficient；Voltage deviation is modified according to preset DC voltage offset value, by preset first formula according to
Weigh coefficient, revised voltage deviation and power deviation and calculates error；Error input PI controller is obtained into d shaft current；In advance
Set the first formula are as follows: δ=K Δ u '+(1-K) Δ p, in formula, Δ u ' is revised voltage deviation, and Δ p is power deviation, and K is
Weigh coefficient.The present invention, which may be implemented to carry out the DC voltage for determining power end control, makes its stabilization, by mathematical function into
It is existing to avoid system concussion caused by different controller switchings on traditional technology for row pattern switching (i.e. the calculating process of error)
As, and before being placed in PI link due to pattern switching, the time of pattern switching is greatly shortened, direct current during failure is reduced
The out-of-limit level of voltage.
Detailed description of the invention
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, below will to embodiment or
Attached drawing needed to be used in the description of the prior art is briefly described, it should be apparent that, the accompanying drawings in the following description is only
Some embodiments of the present invention, for those of ordinary skill in the art, without any creative labor,
It can also be obtained according to these attached drawings other attached drawings.
Fig. 1 is the structural schematic diagram of Traditional DC voltage margin controller；
Fig. 2 is a kind of one embodiment of the DC voltage control method of both-end flexible direct current occasion provided by the invention
Flow diagram；
Fig. 3 is a kind of structural schematic diagram of one embodiment of DC voltage controller provided by the invention；
Fig. 4 is the connection schematic diagram of DC voltage controller provided by the invention and both-end MMC-HVDC system；
Fig. 5 is the schematic diagram of the both-end flexible HVDC transmission system based on MMC；
Fig. 6 is the 2 DC voltage comparison diagram of converter station under different controllers；
The electrical quantity contrast schematic diagram that Fig. 7 is direction of tide when being forward direction；
The electrical quantity contrast schematic diagram that Fig. 8 is direction of tide when being reversed.
Specific embodiment
The embodiment of the invention provides a kind of DC voltage control method of both-end flexible direct current occasion and direct current are voltage-controlled
Device processed is solved when voltage is more than system limiting design value, and handover control system does not carry out stable DC electricity to controller at once
Pressure, the technical problem for causing the voltage overshoot of direct current system voltage excessive.
In order to make the invention's purpose, features and advantages of the invention more obvious and easy to understand, below in conjunction with this hair
Attached drawing in bright embodiment, technical scheme in the embodiment of the invention is clearly and completely described, it is clear that is retouched below
The embodiment stated is only a part of the embodiment of the present invention, and not all embodiment.Based on the embodiments of the present invention, originally
Field those of ordinary skill all other embodiment obtained without making creative work, belongs to this hair
The range of bright protection.
Referring to Fig. 2, an a kind of reality of the DC voltage control method of both-end flexible direct current occasion provided by the invention
Apply example, comprising:
201, get voltage deviation between the direct voltage reference value of sending end and the dc voltage measurements of sending end,
Power deviation between the value and power reference of sending end and the power measurement values of sending end；
Step 201 is accomplished that voltage deviation detection and power deviation detection, and voltage deviation detects mainly by system
When normal operation, the direct voltage reference value U of sending endrefWith voltage measuring value UdcMake difference to generate, output is that voltage deviation is believed
Number Δ u, power deviation detection is mainly by when operating normally, the value and power reference P of sending endrefIt is and power measurement values PacMake
Difference generates output bias signal delta p.
202, tradeoff coefficient is calculated according to voltage deviation and preset voltage deviation factor；
After determining voltage deviation and power deviation, by preset second formula according to preset voltage deviation and voltage deviation
Coefficient calculates tradeoff coefficient；
Preset second formula are as follows:
K=λ1Δu2
In formula, λ1For preset voltage deviation factor, Δ u is voltage deviation.
In the present embodiment, tradeoff COEFFICIENT K is determined according to the size of Δ u.In preset second formula, λ1Greater than zero, examine
Worry is worked as | Δ u | when larger, either high voltage or low-voltage have the biggish characteristic of K.And | Δ u | when=0, K=0, this
Shi Weiding Active power mode is consistent with control model when operating normally.
203, voltage deviation is modified according to preset DC voltage offset value, by preset first formula according to power
Weigh coefficient, revised voltage deviation and power deviation calculating error；
After determining tradeoff coefficient, voltage deviation is carried out according to preset DC voltage offset value by preset third formula
Amendment, then error is calculated according to tradeoff coefficient, revised voltage deviation and power deviation by preset first formula；
Preset third formula are as follows:
Δ u '=Δ u-sign (Δ u) λ2
In formula, (Δ u) is the sign function of Δ u, λ to sign2For preset DC voltage offset value.
Preset first formula are as follows:
δ=K Δ u '+(1-K) Δ p
In formula, Δ u ' is revised voltage deviation, and Δ p is power deviation, and K is tradeoff coefficient.
In the present embodiment, it needs first to be modified voltage deviation, according to preset third formula, λ2Greater than zero.When straight
Galvanic electricity pressure increases when Δ u being caused to be greater than zero,
Δ u '=Δ u- λ2=(Uref-λ2)-Udc
It is equivalent to and has turned down direct voltage reference value, be Uref-λ2, advantageously allow DC voltage decline.Similarly, when straight
When galvanic electricity drops lead to Δ u less than zero,
Δ u '=Δ u+ λ2=(Uref+λ2)-Udc
It is equivalent to and direct voltage reference value has been turned up, be Uref+λ2, advantageously allow DC voltage rising.Therefore, it corrects
DC deviation signal facilitate DC voltage keep stablize.
According to preset first formula it is found that as K=1, δ=Δ u ' is at this time constant voltage control；As K=0, δ=
Δ p, at this time to determine active power controller；It otherwise, is sagging control model.The present invention is determined by the size of K value as a result,
The selection of control model.
204, error input PI controller is obtained into d shaft current；
After obtaining d shaft current, then both-end flexible direct current system can be inputted to d shaft current and carry out subsequent operation, the process
For those skilled in the art well-known technique and be not protection content of the invention, be not described in detail herein.
In embodiments of the present invention, λ1And λ2For two important parameters, i.e., preset DC voltage deviation factor and preset straight
Voltage offset values are flowed, the size of the two values determines to improve the response characteristic of controller.It should be noted that the present invention provides
Both-end flexible direct current occasion DC voltage control method executing subject be DC voltage controller (i.e. invention provide
DC voltage controller), and preset DC voltage deviation factor in the present embodiment and preset DC voltage offset value be through
Cross the Utopian parameter value that training obtains, the training process specifically:
(1) DC voltage controller provided by the invention is accessed into both-end MMC-HVDC system, the position of access is original
MMC-HVDC system is determined at active power outer ring controller, such as Fig. 4.
(2) DC voltage deviation factor and DC voltage offset value, i.e. λ are initialized1And λ2。
(3) two parameters are brought into the DC voltage controller, that is, be input in MMC-HVDC.
(4) short trouble is set, and operation MMC-HVDC emulation exports DC voltage simulation value UDc,And calculating target function
Formula changes target function type are as follows:
In formula, wherein tmIt is fault moment, tnIt is failure finish time.As optimal solution when above-mentioned objective function minimum.
The core of controller provided by the invention is to determine the DC voltage of power end, including system stable operation
The failure of period and the DC voltage stability during recovery, therefore the objective function selected is minimum for DC voltage deviation.
(5) target function value is judged using following criterion, if meeting convergence criterion formula, stops calculating, institute
The parameter asked is parameter current, i.e., using current DC voltage deviation factor and DC voltage offset value as preset direct current
Otherwise pressure deviation factor and preset DC voltage offset value are transferred to (6).
The convergence criterion is the difference of the objective function of the objective function that convergence criterion is nth iteration and (n-1)th iteration
Absolute value be less than setting small quantity, it may be assumed that
|obj(n)-obj(n-1)| < ξ
(6) pass through list suitable for optimizing the optimization of multiple real variables using the simplex method embedded in PSCAD/EMTDC
Pure shape method generates new λ1And λ2, it is transferred to (3).
Controller provided by the invention only contains a PI link, therefore simplifies controller architecture and parameter designing, and
Pattern switching will be constructed by continuous mathematical function, and the system reforming phenomena of different controller switchings be avoided, since mode is cut
It changes before being placed in PI link, greatly shortens the time of pattern switching, the out-of-limit level of DC voltage during reducing failure.
The above is the detailed description carried out to the DC voltage control method of both-end flexible direct current occasion a kind of, for convenient for
Understand, below by with a concrete application scene to the application of the DC voltage control method of both-end flexible direct current occasion a kind of into
Row explanation, application examples include:
The both-end flexible HVDC transmission system shown in fig. 5 based on MMC has been built in PSCAD/EMTDC.The ginseng of system
Number is as shown in the table.
1 MMC-HVDC system parameter of table
(1) controller parameter selects
For conventional voltage nargin control in, voltage margin value UdcrefHAnd UdcrefLCan neither be too big, can not be too small,
The 10% of direct-current transmission voltage rated value can be selected as with reference to the current margins control in Traditional DC transmission of electricity.In addition, right
In the present invention relates to constant voltage, the parameter of constant dc power control it is as shown in table 2.
2 conventional controller types of table
For optimization voltage margin control, three phase short circuit fault occurs with 1 AC system side of converter station, and (transition resistance is
10 Europe) for be illustrated.Formula (8) is needed to instruct range of integration, therefore sets fault moment tm=1.0s, therefore
Barrier removes moment tn=1.2s.As a result, to DC voltage deviation factor λ1With DC voltage offset value λ2It is trained, obtains excellent
Optimal solution after change are as follows:
λ1 (n)=12.1, λ2 (n)=5.3
Wherein n is the number of iterations, and n=80.
(2) converter station 2 exchanges the experiment of side fault traversing
In order to verify the reasonability of original constant voltage controller and voltage margin controller parameter, the hair of converter station 2 is devised
The experiment of raw exchange side failure.This is because converter station 1 uses constant DC voltage control, if parameter setting is reasonable,
Converter station 2 occurs to be able to maintain DC voltage stability when AC fault；On the other hand, voltage margin is controlled in 2 side of converter station
Negative interaction cannot be brought for DC voltage stability effect when it exchanges side and breaks down for traditional constant dc power control.
In this regard, with t0=1.0s to t1In (non-constant DC voltage control end) the AC system side of converter station 2 three-phase shortcircuit occurs for=1.2s
For failure, comparison 2 no-voltage controller of converter station, conventional voltage nargin controller and the improvement voltage margin controller change of current
Stand 2 DC voltage contrast effect it is as shown in Figure 6.
After AC fault occurs for converter station 2 (i.e. non-dc voltage controling end), converter station 2 using constant dc power control and
DC voltage can be maintained within (1 ± 15%) using voltage margin control, and stablizing effect is essentially identical, demonstrates
Related Rational Parameters, and voltage margin control will not influence 1 stable DC voltage effect of converter station.
(3) converter station 1 exchanges the experiment of side fault traversing
With t0In (constant DC voltage control end) the AC system side of converter station 1 three phase short circuit fault (transition occurs for=1.0s
Resistance is 10 Europe, duration 0.2s) for be illustrated, set converter station 2 determines active power command value as 0.9pu,
And it is accounted for according to two kinds of direction of tide.Regulation direction of tide is positive when being converter station 2 to 1, otherwise is reversed.Fig. 7~
Fig. 8 lists the feelings of the DC voltage of converter station 2 and two kinds of voltage margin controller output current-orders under two kinds of direction of tide
Condition.
Fig. 7 lists the comparison of the electrical quantity when trend is positive, and system produces transient overvoltage at this time.However, from
It sees on the whole, mentioned optimal control method has a distinct increment than the ability of the stable DC voltage of traditional controller.From controller
From the point of view of output, t0For fault moment, optimal controller is adjusted immediately, such as electric current idrefIt is shown, but traditional controller at this time
There is no movement, but controller just starts to act when voltage being waited to rise to definite value (1.1pu), which corresponds to t1, immediately
I in figuredrefPIt is gradually increasing, idrefHIt is gradually reduced, when both are equal (corresponding t2Moment) just it is switched to that determine direct current voltage-controlled
System.It can be seen that conventional voltage nargin control be switched to determine DC voltage time it is t more late than optimal control2-t0Time, make
At the positive overshoot of the former about 0.09pu higher than the peak value of the latter.
Fig. 8 lists the comparison of the electrical quantity when trend is reversed, and system produces transient state low-voltage at this time.From figure
As a result as it can be seen that mentioned control method still has preferable control performance at low voltage, DC voltage control is mentioned than conventional method
High about 0.1pu.Similar with Fig. 7, traditional controller is more late than the time that optimal controller plays the role of determining DC voltage at this time
Time, therefore it is larger to cause later low-voltage overshoot.
The above are one embodiment of a kind of DC voltage control method of both-end flexible direct current occasion, below will be to this
A kind of DC voltage controller that invention provides is illustrated, referring to Fig. 3, the present invention also provides a kind of direct current is voltage-controlled
One embodiment of device processed, comprising: the first comparison module 301, the second comparison module 302, coefficient selection module 303, mode are cut
Change the mold block 304 and PI controller 305；
First comparison module 301 is connect with coefficient selection module 303；
First comparison module 301, the second comparison module 302 are connect with mode switch module 304 respectively；
The connection of coefficient selection module 303 is connect with mode switch module 304；
Mode switch module 304 is connect with PI controller 305；
First comparison module 301 is used to get the dc voltage measurements of direct voltage reference value and sending end, and to straight
Stream voltage reference value and the dc voltage measurements of sending end obtain voltage deviation as difference；
Second comparison module 302 is used to get the power measurement values of value and power reference and sending end, and to value and power reference
Power deviation is obtained as difference with the power measurement values of sending end；
Coefficient selection module 303 is used to calculate tradeoff coefficient according to voltage deviation and preset voltage deviation factor；
Mode switch module 304 is for being modified voltage deviation according to preset DC voltage offset value, by preset
First formula calculates error according to tradeoff coefficient, revised voltage deviation and power deviation；
PI controller 305 is for carrying out error d shaft current is calculated；
Preset first formula are as follows:
δ=K Δ u '+(1-K) Δ p
In formula, Δ u ' is revised voltage deviation, and Δ p is power deviation, and K is tradeoff coefficient.
Further, coefficient selection module 303 is also used to through preset second formula according to preset voltage deviation and electricity
Deviation factor is pressed to calculate tradeoff coefficient；
Preset second formula are as follows:
K=λ1Δu2
In formula, λ1For preset voltage deviation factor, Δ u is voltage deviation.
Further, mode switch module 304 specifically includes:
First computing unit, for by preset third formula according to preset DC voltage offset value to voltage deviation into
Row amendment；
Preset third formula are as follows:
Δ u '=Δ u-sign (Δ u) λ2
In formula, (Δ u) is the sign function of Δ u, λ to sign2For preset DC voltage offset value；
Second computing unit, for passing through preset first formula according to tradeoff coefficient, revised voltage deviation and power
Deviation calculates error；
Preset first formula are as follows:
δ=K Δ u '+(1-K) Δ p
In formula, Δ u ' is revised voltage deviation, and Δ p is power deviation, and K is tradeoff coefficient.
It is apparent to those skilled in the art that for convenience and simplicity of description, foregoing description is
System, the specific work process of device and unit can refer to corresponding processes in the foregoing method embodiment, and details are not described herein.
In several embodiments provided herein, it should be understood that disclosed system, device and method can be with
It realizes by another way.For example, the apparatus embodiments described above are merely exemplary, for example, the unit
It divides, only a kind of logical function partition, there may be another division manner in actual implementation, such as multiple units or group
Part can be combined or can be integrated into another system, or some features can be ignored or not executed.Another point, it is shown
Or the mutual coupling, direct-coupling or communication connection discussed can be through some interfaces, between device or unit
Coupling or communication connection are connect, can be electrical property, mechanical or other forms.
The unit as illustrated by the separation member may or may not be physically separated, as unit
The component of display may or may not be physical unit, it can and it is in one place, or may be distributed over more
In a network unit.Some or all of unit therein can be selected to realize this embodiment scheme according to the actual needs
Purpose.
It, can also be in addition, the functional units in various embodiments of the present invention may be integrated into one processing unit
It is that each unit physically exists alone, can also be integrated in one unit with two or more units.Above-mentioned integrated list
Member both can take the form of hardware realization, can also realize in the form of software functional units.
If the integrated unit is realized in the form of SFU software functional unit and sells or use as independent product
When, it can store in a computer readable storage medium.Based on this understanding, technical solution of the present invention essence
On all or part of the part that contributes to existing technology or the technical solution can be with the shape of software product in other words
Formula embodies, which is stored in a storage medium, including some instructions are used so that a calculating
Machine equipment (can be personal computer, server or the network equipment etc.) executes each embodiment the method for the present invention
All or part of the steps.And storage medium above-mentioned includes: USB flash disk, mobile hard disk, read-only memory (ROM, Read-Only
Memory), random access memory (RAM, Random Access Memory), magnetic or disk etc. are various can store
The medium of program code.
The above, the above embodiments are merely illustrative of the technical solutions of the present invention, rather than its limitations；Although reference
Invention is explained in detail for previous embodiment, those skilled in the art should understand that: it still can be right
Technical solution documented by foregoing embodiments is modified or equivalent replacement of some of the technical features；And this
It modifies or replaces, the spirit and model of technical solution of various embodiments of the present invention that it does not separate the essence of the corresponding technical solution
It encloses.
Claims (6)
1. a kind of DC voltage control method of both-end flexible direct current occasion characterized by comprising
Get the power of voltage deviation between the direct voltage reference value of sending end and the dc voltage measurements of sending end, sending end
Power deviation between reference value and the power measurement values of sending end；
Tradeoff coefficient is calculated according to the voltage deviation and preset voltage deviation factor；
The voltage deviation is modified according to preset DC voltage offset value, by preset first formula according to the tradeoff
Coefficient, the revised voltage deviation and the power deviation calculate error；
Error input PI controller is obtained into d shaft current；
Preset first formula are as follows:
δ=K Δ u '+(1-K) Δ p
In formula, Δ u ' is revised voltage deviation, and Δ p is power deviation, and K is tradeoff coefficient.
2. the DC voltage control method of both-end flexible direct current occasion according to claim 1, which is characterized in that described
Tradeoff coefficient is calculated according to the voltage deviation and preset voltage deviation factor specifically:
Tradeoff coefficient is calculated according to preset voltage deviation and the voltage deviation coefficient by preset second formula；
Preset second formula are as follows:
K=λ1Δu2
In formula, λ1For preset voltage deviation factor, Δ u is voltage deviation.
3. the DC voltage control method of both-end flexible direct current occasion according to claim 2, which is characterized in that described
The voltage deviation is modified according to preset DC voltage offset value specifically:
The voltage deviation is modified according to preset DC voltage offset value by preset third formula；
The preset third formula are as follows:
Δ u '=Δ u-sign (Δ u) λ2
In formula, (Δ u) is the sign function of Δ u, λ to sign2For preset DC voltage offset value.
4. a kind of DC voltage controller characterized by comprising the first comparison module, the second comparison module, coefficient select mould
Block, mode switch module and PI controller；
First comparison module is connect with the coefficient selection module；
First comparison module, second comparison module are connect with the mode switch module respectively；
The coefficient selection module connection is connect with the mode switch module；
The mode switch module is connect with the PI controller；
First comparison module is used to get the dc voltage measurements of direct voltage reference value and sending end, and to described straight
Stream voltage reference value and the dc voltage measurements of sending end obtain voltage deviation as difference；
Second comparison module is used to get the power measurement values of value and power reference and sending end, and to the value and power reference
Power deviation is obtained as difference with the power measurement values of sending end；
The coefficient selection module is used to calculate tradeoff coefficient according to the voltage deviation and preset voltage deviation factor；
The mode switch module is for being modified the voltage deviation according to preset DC voltage offset value, by preset
First formula calculates error according to the tradeoff coefficient, the revised voltage deviation and the power deviation；
The PI controller is for carrying out the error d shaft current is calculated；
Preset first formula are as follows:
δ=K Δ u '+(1-K) Δ p
In formula, Δ u ' is revised voltage deviation, and Δ p is power deviation, and K is tradeoff coefficient.
5. DC voltage controller according to claim 4, which is characterized in that the coefficient selection module is also used to pass through
Preset second formula calculates tradeoff coefficient according to preset voltage deviation and the voltage deviation coefficient；
Preset second formula are as follows:
K=λ1Δu2
In formula, λ1For preset voltage deviation factor, Δ u is voltage deviation.
6. DC voltage controller according to claim 5, which is characterized in that the mode switch module specifically includes:
First computing unit, for being carried out according to preset DC voltage offset value to the voltage deviation by preset third formula
Amendment；
The preset third formula are as follows:
Δ u '=Δ u-sign (Δ u) λ2
In formula, (Δ u) is the sign function of Δ u, λ to sign2For preset DC voltage offset value；
Second computing unit, for by preset first formula according to the tradeoff coefficient, the revised voltage deviation and
The power deviation calculates error；
Preset first formula are as follows:
δ=K Δ u '+(1-K) Δ p
In formula, Δ u ' is revised voltage deviation, and Δ p is power deviation, and K is tradeoff coefficient.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810015275.0A CN108964105A (en) | 2018-01-08 | 2018-01-08 | The DC voltage control method and DC voltage controller of both-end flexible direct current occasion |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810015275.0A CN108964105A (en) | 2018-01-08 | 2018-01-08 | The DC voltage control method and DC voltage controller of both-end flexible direct current occasion |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN108964105A true CN108964105A (en) | 2018-12-07 |
Family
ID=64495433
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810015275.0A Pending CN108964105A (en) | 2018-01-08 | 2018-01-08 | The DC voltage control method and DC voltage controller of both-end flexible direct current occasion |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108964105A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110323774A (en) * | 2019-07-04 | 2019-10-11 | 许继电气股份有限公司 | A kind of DC line fault method for restarting, VSC control method and device |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103178539A (en) * | 2013-03-21 | 2013-06-26 | 浙江省电力公司电力科学研究院 | Direct current voltage deviation slope control method for multi-end flexible direct current power transmission system |
| JP2015220986A (en) * | 2014-05-13 | 2015-12-07 | エルエス産電株式会社Ｌｓｉｓ Ｃｏ．，Ｌｔｄ． | HVDC system |
| CN105244902A (en) * | 2015-10-23 | 2016-01-13 | 南方电网科学研究院有限责任公司 | Direct-current voltage slope control method and system of multi-terminal flexible direct-current power transmission system |
| CN105281356A (en) * | 2015-11-10 | 2016-01-27 | 中国科学院电工研究所 | Coordination control method of multi-terminal flexible direct-current power transmission system |
| CN106451515A (en) * | 2016-08-17 | 2017-02-22 | 东北电力大学 | Generalized sagging control method suitable for multi-terminal flexible direct current power transmission system |
-
2018
- 2018-01-08 CN CN201810015275.0A patent/CN108964105A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103178539A (en) * | 2013-03-21 | 2013-06-26 | 浙江省电力公司电力科学研究院 | Direct current voltage deviation slope control method for multi-end flexible direct current power transmission system |
| JP2015220986A (en) * | 2014-05-13 | 2015-12-07 | エルエス産電株式会社Ｌｓｉｓ Ｃｏ．，Ｌｔｄ． | HVDC system |
| CN105244902A (en) * | 2015-10-23 | 2016-01-13 | 南方电网科学研究院有限责任公司 | Direct-current voltage slope control method and system of multi-terminal flexible direct-current power transmission system |
| CN105281356A (en) * | 2015-11-10 | 2016-01-27 | 中国科学院电工研究所 | Coordination control method of multi-terminal flexible direct-current power transmission system |
| CN106451515A (en) * | 2016-08-17 | 2017-02-22 | 东北电力大学 | Generalized sagging control method suitable for multi-terminal flexible direct current power transmission system |
Non-Patent Citations (2)
| Title |
|---|
| 李梅航: "适用于多端柔性直流输电系统的快速电压裕度控制策略", 《电网技术》 * |
| 陈朋: "适用于多端柔性直流输电系统的通用控制策略", 《电力系统自动化》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110323774A (en) * | 2019-07-04 | 2019-10-11 | 许继电气股份有限公司 | A kind of DC line fault method for restarting, VSC control method and device |
| CN110323774B (en) * | 2019-07-04 | 2020-11-13 | 许继电气股份有限公司 | Direct-current line fault restarting method, VSC control method and device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107508322B (en) | A kind of short-circuit fault of power system computational methods for considering photovoltaic electric station grid connection | |
| CN108039718B (en) | Improved flexible direct-current voltage control method and system | |
| CN106961121B (en) | Seamless switching control system and strategy based on current indirect control and sagging control | |
| CN105974983B (en) | The control method that a kind of digital voltage ring is followed mutually with electric current loop | |
| CN110350552B (en) | Droop control rapid secondary compensation method applied to direct-current micro-grid | |
| CN110544960A (en) | distributed control method for improving reactive power sharing capability of island microgrid | |
| CN111416376A (en) | Voltage balancing method for extra-high voltage flexible direct-current constant active power MMC converter station | |
| CN108964105A (en) | The DC voltage control method and DC voltage controller of both-end flexible direct current occasion | |
| CN114139364A (en) | Electromechanical-electromagnetic hybrid simulation method and device based on hybrid direct current system | |
| CN112653176B (en) | Variable working point droop control method for multi-end flexible direct current system | |
| CN110071499B (en) | Method and system for rapidly judging safety loop closing of power distribution network | |
| CN108363846A (en) | A kind of electromagnetism DC Model automatic adjusting method and system based on hybrid simulation | |
| CN107607885A (en) | A kind of variable-frequency power sources pilot system and its experimental control method | |
| CN106856334B (en) | A kind of power system state estimation method considering flexible direct current control characteristic | |
| CN105515025A (en) | Three-phase unbalance optimization method for low-voltage power distribution network | |
| CN113489044B (en) | Multi-terminal flexible direct current transmission self-adaptive droop control method considering line resistance | |
| CN112765920B (en) | Direct-current short-circuit current calculation method and system based on differential-common mode transformation | |
| CN109217384A (en) | More distributed generation resource power distribution methods based on the sagging control of active phase angle | |
| CN107026483B (en) | A kind of compound phase shifting control strategy under the DC transmission system inverter side AC fault suitable for LCC | |
| CN107562971B (en) | Alternating current/direct current power grid power flow calculation method based on PSS/E | |
| CN112260314A (en) | Phase-locked synchronous stable control method and system during fault ride-through period of wind turbine generator | |
| CN109842135B (en) | 1/3 capacity regulating method for capacity regulating transformer with balance winding and Dyn connection capacity regulating transformer | |
| CN113300402B (en) | Self-adaptive virtual impedance control method and system for LCC converter station | |
| CN115296333B (en) | Voltage balance control method based on ultra-high voltage direct current transmission system transmitting end LCC converter station | |
| CN113765121B (en) | VSC/LCC parallel hybrid multi-feed system commutation failure recovery method and system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20181207 |
|
| RJ01 | Rejection of invention patent application after publication |