CN116131366A - Coordinated control method for transient stability and safe supporting capacity of network-structured VSC system - Google Patents
Coordinated control method for transient stability and safe supporting capacity of network-structured VSC system Download PDFInfo
- Publication number
- CN116131366A CN116131366A CN202310049853.3A CN202310049853A CN116131366A CN 116131366 A CN116131366 A CN 116131366A CN 202310049853 A CN202310049853 A CN 202310049853A CN 116131366 A CN116131366 A CN 116131366A
- Authority
- CN
- China
- Prior art keywords
- vsc
- voltage
- coefficient
- power angle
- feedforward
- 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.)
- Granted
Links
- 230000001052 transient effect Effects 0.000 title claims abstract description 115
- 238000000034 method Methods 0.000 title claims abstract description 55
- 238000007665 sagging Methods 0.000 claims description 20
- 239000003990 capacitor Substances 0.000 claims description 12
- 238000003860 storage Methods 0.000 claims description 12
- OIGNJSKKLXVSLS-VWUMJDOOSA-N prednisolone Chemical compound O=C1C=C[C@]2(C)[C@H]3[C@@H](O)C[C@](C)([C@@](CC4)(O)C(=O)CO)[C@@H]4[C@@H]3CCC2=C1 OIGNJSKKLXVSLS-VWUMJDOOSA-N 0.000 claims description 11
- 238000004590 computer program Methods 0.000 claims description 10
- 238000010586 diagram Methods 0.000 description 12
- 230000004044 response Effects 0.000 description 11
- 230000006870 function Effects 0.000 description 6
- 238000011217 control strategy Methods 0.000 description 5
- 230000008569 process Effects 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 230000001360 synchronised effect Effects 0.000 description 4
- 238000009826 distribution Methods 0.000 description 3
- 238000013016 damping Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 238000010248 power generation Methods 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Images
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
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
- H02J3/48—Controlling the sharing of the in-phase component
-
- 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
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
- H02J3/16—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load by adjustment of reactive power
-
- 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
- H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
- H02J3/241—The oscillation concerning frequency
-
- 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)
- Supply And Distribution Of Alternating Current (AREA)
- Control Of Electrical Variables (AREA)
Abstract
The invention discloses a coordination control method and a coordination control system for transient stability and safe supporting capacity of a network-structured VSC system, wherein the coordination control method comprises the following steps: determining a functional relation between the total output current amplitude of the network-structured VSC system and reactive voltage control link parameters; determining a constraint condition based on the functional relation and the maximum current amplitude, determining a maximum droop coefficient of the transient grid-formed VSC system capable of maintaining a voltage source control mode based on the constraint condition, and adjusting the droop coefficient based on the maximum droop coefficient; obtaining a fault degree coefficient of PCC side voltage in a current operation mode, and determining a feedforward compensation power angle based on the fault degree coefficient and the functional relation; and determining transient feedforward active power based on the feedforward compensation power angle, and feedforward the transient feedforward active power to an active frequency control link of the network-structured VSC system to improve an input active power reference value so as to realize coordinated control of transient stability and safety supporting capacity of the network-structured VSC system.
Description
Technical Field
The invention relates to the technical field of network-structured converters, in particular to a coordination control method and system for transient stability and safety support capacity of a network-structured VSC system.
Background
With the continuous development of new energy power generation, the power supply structure of the power system in China is obviously changed, the duty ratio of the traditional synchronous power generation equipment is gradually reduced, the power electronic power supply permeability of a voltage source converter (voltage source converter, VSC) interface is continuously increased, the potential of the power electronic power supply based on the VSC is further explored, and the method is an urgent need for future power grid development. In recent years, a Grid Formation (GFM) technology has been attracting attention as a possible solution to the system transformation. The GFM control is essentially a voltage source control mode (voltage control mode, VCM) which is different from the grid-following control, and the amplitude and the phase of the port voltage are formed independently by a power synchronization method, so that the power required by the system is output, and the grid-connected synchronous operation is realized. The thought of modeling the grid-connected characteristic of the synchronous machine improves the active supporting capability of the power electronic power supply with the VSC interface, ensures the continuation of a power system stability research system, and cannot avoid the problem of transient stability under the traditional large disturbance. In addition, considering the hardware overcurrent capability of the power electronic equipment, the transient safety problem is easy to occur when the actual GFM-VSC system operates under the large disturbance, and the problem that how to ensure the transient stability and safety of the GFM-VSC under the premise of maintaining the VCM characteristic and simultaneously maximize the active supporting capability of an external power grid is urgent to be solved.
Therefore, there is a need for an improved control method for coordinating the transient stability, safety and support capabilities of a networked VSC system.
Disclosure of Invention
The invention provides a control method and a control system for transient stability and safety support capacity of a coordinated network-structured VSC (GFM-VSC) system, which are used for solving the problem that how to ensure the transient stability and safety of the GFM-VSC system per se and maximize the active support capacity of an external power grid on the premise of maintaining the VCM characteristic under large disturbance.
In order to solve the above-mentioned problems, according to an aspect of the present invention, there is provided a coordinated control method of transient stability and safety support capability of a network-structured VSC system, the method comprising:
determining a functional relation between the total output current amplitude of the network-structured VSC system and reactive voltage control link parameters;
determining a constraint condition based on the functional relation and the maximum current amplitude, determining a maximum droop coefficient of the transient grid-formed VSC system capable of maintaining a voltage source control mode based on the constraint condition, and adjusting the droop coefficient based on the maximum droop coefficient;
obtaining a fault degree coefficient of PCC side voltage in a current operation mode, and determining a feedforward compensation power angle based on the fault degree coefficient and the functional relation;
And determining transient feedforward active power based on the feedforward compensation power angle, and feedforward the transient feedforward active power to an active frequency control link of the network-structured VSC system to improve an input active power reference value so as to realize coordinated control of transient stability and safety supporting capacity of the network-structured VSC system.
Preferably, wherein the functional relationship comprises:
wherein I is L The total output current amplitude for the grid-formed VSC; i L,d And I L,q Outputting current for an inner ring dq axis of the network-structured VSC system; ρ is a fault degree coefficient of the grid voltage; delta is a virtual power angle; k (K) Q Is a sagging coefficient; q (Q) N And U N Rated reactive power and voltage amplitude respectively; c (C) 1 A filter capacitor which is GFM-VSC; u (U) PCC A PCC side PCC voltage magnitude; x is X L Is the line inductance; omega is fundamental voltage reference angular frequency; delta is the intermediate quantity; u (U) ref The voltage reference amplitude for a grid-type VSC.
Preferably, wherein the constraint comprises:
wherein I is L The total output current amplitude for the grid-formed VSC; i L,d And I L,q Outputting current for an inner ring dq axis of the network-structured VSC system; ρ is a fault degree coefficient of the grid voltage; delta is a virtual power angle; k (K) Q Is a sagging coefficient; q (Q) N And U N Rated reactive power and voltage amplitude respectively; i max Is the maximum current amplitude; wherein by lowering K Q In such a way that the net VSC system always has a total output current amplitude I within the interval ρ ε (0, 1) L Less than maximum current amplitude constraint I max The range of the power angle, i.e. the virtual power angle delta is always solvedOn the premise of determining the maximum sagging coefficient.
Preferably, wherein said determining a feedforward compensation power angle based on said fault extent coefficient and said functional relationship comprises:
when the fault degree coefficient is equal to 1, the rated current amplitude I is calculated N As the total output current amplitude of the grid-formed VSC, and combining the fault extent coefficient and the rated current amplitude I N Substituting the virtual power angle into the functional relation to obtain the virtual power angle at the moment as a feedforward compensation power angle;
when the failure degree coefficient is not equal to 1, the maximum current amplitude I is calculated max As the total output current amplitude of the grid-formed VSC and combining the fault extent coefficient and the maximum current amplitude I max Substituting the virtual power angle into the functional relation, and acquiring the virtual power angle at the moment as a feedforward compensation power angle.
Preferably, wherein said determining a transient feedforward active power based on said feedforward compensation power angle comprises:
wherein P is N * Is transient feedforward active power; ρ is a fault degree coefficient of the grid voltage; u (U) VSC And U N The voltage amplitude of the actual port and the rated voltage amplitude of the net-structured VSC system are respectively; p (P) N Rated power of the network-structured VSC system; delta F Compensating the power angle for feedforward; delta 0 Is a virtual power angle in the initial running state of the system.
According to another aspect of the present invention there is provided a coordinated control system of transient stability and safety support capability of a networked VSC system, the system comprising:
the function relation determining unit is used for determining a function relation between the total output current amplitude of the network-structured VSC system and reactive voltage control link parameters;
a droop coefficient adjustment unit, configured to determine a constraint condition based on the functional relationship and a maximum current amplitude, determine a maximum droop coefficient of a transient-state grid-formed VSC system capable of maintaining a voltage source control mode based on the constraint condition, and adjust the droop coefficient based on the maximum droop coefficient;
the feedforward compensation power angle determining unit is used for obtaining a fault degree coefficient of the PCC side voltage in the current operation mode and determining a feedforward compensation power angle based on the fault degree coefficient and the functional relation;
and the feedforward control unit is used for determining transient feedforward active power based on the feedforward compensation power angle, and feedforward the transient feedforward active power to an active frequency control link of the network-structured VSC system so as to improve an input active power reference value and realize coordination control of transient stability and safety supporting capacity of the network-structured VSC system.
Preferably, wherein the functional relationship comprises:
wherein I is L The total output current amplitude for the grid-formed VSC; i L,d And I L,q Outputting current for an inner ring dq axis of the network-structured VSC system; ρ is a fault degree coefficient of the grid voltage; delta is a virtual power angle; k (K) Q Is a sagging coefficient; q (Q) N And U N Rated reactive power and voltage amplitude respectively; c (C) 1 A filter capacitor which is GFM-VSC; u (U) PCC A PCC side PCC voltage magnitude; x is X L Is the line inductance; omega is fundamental voltage reference angular frequency; delta is the intermediate quantity; u (U) ref The voltage reference amplitude for a grid-type VSC.
Preferably, wherein the constraint comprises:
wherein I is L The total output current amplitude for the grid-formed VSC; i L,d And I L,q Outputting current for an inner ring dq axis of the network-structured VSC system; ρ is a fault degree coefficient of the grid voltage; delta is a virtual power angle; k (K) Q Is a sagging coefficient; q (Q) N And U N Rated reactive power and voltage amplitude respectively; i max Is the maximum current amplitude; wherein by lowering K Q In such a way that the net VSC system always has a total output current amplitude I within the interval ρ ε (0, 1) L Less than maximum current amplitude constraint I max The maximum sagging coefficient is determined on the premise that the virtual power angle delta always has a solution.
Preferably, the feedforward compensation power angle determining unit determines the feedforward compensation power angle based on the fault degree coefficient and the functional relation, and includes:
when the fault degree coefficient is equal to 1, the rated current amplitude I is calculated N As the total output current amplitude of the grid-formed VSC, and combining the fault extent coefficient and the rated current amplitude I N Substituting the virtual power angle into the functional relation to obtain the virtual power angle at the moment as a feedforward compensation power angle;
when the failure degree coefficient is not equal to 1, the maximum current amplitude I is calculated max As the total output current amplitude of the grid-formed VSC and combining the fault extent coefficient and the maximum current amplitude I max Substituting the virtual power angle into the functional relation, and acquiring the virtual power angle at the moment as a feedforward compensation power angle.
Preferably, the feedforward control unit determines a transient feedforward active power based on the feedforward compensation power angle, including:
wherein P is N * Is transient feedforward active power; ρ is a fault degree coefficient of the grid voltage; u (U) VSC And U N Are respectively net-structured VSC system realityThe voltage amplitude of the inter-port and the rated voltage amplitude; p (P) N Rated power of the network-structured VSC system; delta F Compensating the power angle for feedforward; delta 0 Is a virtual power angle in the initial running state of the system.
Based on another aspect of the present invention, there is provided a computer readable storage medium having stored thereon a computer program which when executed by a processor implements the steps of any one of the methods for coordinated control of transient stability and safe support capabilities of a networked VSC system.
Based on another aspect of the present invention, the present invention provides an electronic device, including:
the computer readable storage medium as described above; and
one or more processors configured to execute the programs in the computer-readable storage medium.
The invention provides a coordination control method and a coordination control system for transient stability and safety support capacity of a network-structured VSC system, wherein the coordination control method comprises the following steps: determining a functional relation between the total output current amplitude of the network-structured VSC system and reactive voltage control link parameters; determining a constraint condition based on the functional relation and the maximum current amplitude, determining a maximum droop coefficient of the transient grid-formed VSC system capable of maintaining a voltage source control mode based on the constraint condition, and adjusting the droop coefficient based on the maximum droop coefficient; obtaining a fault degree coefficient of PCC side voltage in a current operation mode, and determining a feedforward compensation power angle based on the fault degree coefficient and the functional relation; and determining transient feedforward active power based on the feedforward compensation power angle, and feedforward the transient feedforward active power to an active frequency control link of the network-structured VSC system to improve an input active power reference value so as to realize coordinated control of transient stability and safety supporting capacity of the network-structured VSC system. The transient performance enhancement module is formed by the droop coefficient remodelling of the reactive voltage control loop and the transient active power feedforward link, so that the GFM-VSC system can maintain the VCM characteristic in the whole fault process, and the active support is provided for an external power grid on the premise of meeting the self transient safety and stability.
Drawings
Exemplary embodiments of the present invention may be more completely understood in consideration of the following drawings:
fig. 1 is a flow chart of a coordinated control method 100 of transient stability and safety support capability of a networked VSC system according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a topology and a control strategy of a network VSC system according to an embodiment of the present invention;
fig. 3 (a) and (b) are inner loop current amplitude profiles of a grid-built VSC system under different coordinate systems, respectively, according to an embodiment of the present invention;
fig. 4 (a), (b), (d) and (d) are inner loop current magnitude profiles, respectively, of a grid-built VSC system with different droop coefficients, according to embodiments of the present invention;
fig. 5 is a schematic diagram of a GFM-VSC system transient active power feedforward control in accordance with an embodiment of the invention;
fig. 6 is a graph of a transient response waveform of the GFM-VSC system without clipping limitation;
fig. 7 is a waveform diagram of the transient response of the GFM-VSC system with additional d-axis current priority clipping in accordance with an embodiment of the invention;
fig. 8 is a waveform diagram of transient response of the GFM-VSC system under an improved control method according to an embodiment of the invention;
fig. 9 is a schematic structural diagram of a coordinated control system 900 of transient stability and safety support capability of a networked VSC system according to an embodiment of the present invention.
Detailed Description
The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the examples described herein, which are provided to fully and completely disclose the present invention and fully convey the scope of the invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, like elements/components are referred to by like reference numerals.
Unless otherwise indicated, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art. In addition, it will be understood that terms defined in commonly used dictionaries should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.
Fig. 1 is a flow chart of a coordinated control method 100 of transient stability and safety support capability of a networked VSC system according to an embodiment of the present invention. As shown in fig. 1, in the coordinated control method for transient stability and safety support capability of the network VSC system provided by the embodiment of the invention, a transient performance enhancement module is formed by the droop coefficient remodelling of the reactive voltage control loop and the transient active power feedforward link, so that the GFM-VSC system can maintain the VCM characteristic in the whole fault process, and the active support is provided for an external power grid on the premise of meeting the self transient safety and stability. The coordinated control method 100 for transient stability and safe supporting capability of the grid-connected VSC system provided by the embodiment of the present invention starts from step 101, and in step 101, a functional relationship between the total output current amplitude and reactive voltage control link parameters of the grid-connected VSC system is determined.
Preferably, wherein the functional relationship comprises:
wherein I is L The total output current amplitude for the grid-formed VSC; i L,d And I L,q Outputting current for an inner ring dq axis of the network-structured VSC system; ρ is a fault degree coefficient of the grid voltage; delta is a virtual power angle; k (K) Q Is a sagging coefficient; q (Q) N And U N Rated reactive power and voltage amplitude respectively; c (C) 1 A filter capacitor which is GFM-VSC; u (U) PCC A PCC side PCC voltage magnitude; x is X L Is the line inductance; omega is fundamental voltage reference angular frequency; delta is the intermediate quantity; u (U) ref The voltage reference amplitude for a grid-type VSC.
In step 102, a constraint is determined based on the functional relationship and the maximum current magnitude, a maximum droop coefficient for which the transient grid-tied VSC system is capable of maintaining the voltage source control mode is determined based on the constraint, and the droop coefficient is adjusted based on the maximum droop coefficient.
Preferably, wherein the constraint comprises:
wherein I is L The total output current amplitude for the grid-formed VSC; i L,d And I L,q Outputting current for an inner ring dq axis of the network-structured VSC system; ρ is a fault degree coefficient of the grid voltage; delta is a virtual power angle; k (K) Q Is a sagging coefficient; q (Q) N And U N Rated reactive power and voltage amplitude respectively; i max Is the maximum current amplitude; wherein by lowering K Q In such a way that the net VSC system always has a total output current amplitude I within the interval ρ ε (0, 1) L Less than maximum current amplitude constraint I max The maximum sagging coefficient is determined on the premise that the virtual power angle delta always has a solution.
In the invention, based on the topological structure and the control strategy of the GFM-VSC grid-connected system, the control equation of the GFM-VSC system and the power injected through the line impedance are deduced. Comprising the following steps:
step 1-1: based on the control strategy of the GFM-VSC system, the control equation for deriving the GFM-VSC is as follows:
wherein: j (J) vir Is a virtual inertia coefficient; u (U) ref And omega ref The voltage reference amplitude and the virtual angular frequency are GFM-VSC; d (D) P And K is equal to P For damping and active frequency coefficients, respectively, an ac adjustment coefficient K is defined AC ＝K P +D P ；K Q Is the reactive voltage amplitude coefficient; p (P) N And omega g Rated power and PCC side angular frequency respectively; q (Q) N And U N Rated reactive power and voltage amplitude, respectively.
Step 1-2: considering that the voltage-current inner loop control response speed is far greater than the power outer loop control response speed, the port voltage actual value U of the GFM-VSC system can be set VSC Equal to the reference value U ref The method comprises the steps of carrying out a first treatment on the surface of the With PCC side voltage as reference, the system injects active power P into the power grid through line impedance T And reactive power Q T The method comprises the following steps:
wherein: u (U) PCC A PCC side PCC voltage magnitude; x is X L Is the line inductance; delta is the phase difference between the GFM-VSC port voltage and the PCC side voltage, and may be referred to as the virtual power angle.
And then, a parameter remolding method of the sagging coefficient in reactive voltage control is deduced on the basis of maintaining VCM constraint and transient safety constraint by a GFM-VSC system. Comprising the following steps:
step 2-1: deriving a port voltage reference value of the GFM-VSC based on the foregoing step 1:
step 2-2: based on the port voltage reference value obtained in the step 2-1, the internal ring dq axis output currents of the GFM-VSC system under transient state are respectively obtained as follows:
wherein: ρ is the degree of grid voltage failureCoefficients; c (C) 1 The filter capacitor is a GFM-VSC, and the value of the filter capacitor is smaller and negligible; i L,d And I L,q The current is output for the inner ring dq axis of the GFM-VSC system.
Step 2-3: based on the internal ring dq axis output current of the GFM-VSC system obtained in the step 2-2, the total output current amplitude I of the GFM-VSC can be obtained L The method comprises the following steps:
step 2-4: determining the initial value of the reactive voltage control loop parameter as K according to the steady-state operating point requirement and the allowable voltage fluctuation range of the system Q0 ,U N0 Q and N0 substituting the current into the formula (5) can obtain the current amplitude distribution rule of the GFM-VSC system under different voltage faults and different power angle positions.
Step 2-5: based on the distribution rule, K is reduced Q The GFM-VSC system can always have the total output current amplitude I in the interval rho epsilon (0, 1) L Less than maximum current amplitude constraint I max The virtual power angle delta always has a solution in the following formula. Thus, the constraint is determined as:
step 2-6: constrained by equation (6), the maximum sag factor K of the GFM-VSC system required to maintain VCM characteristics in transient state can be obtained Q1 . At this time, the initial value K of the sag coefficient of the reactive voltage ring is set Q0 Adjust to K Q1 The GFM-VSC can meet transient safety under large disturbance and has VCM characteristics all the time.
In step 103, a fault degree coefficient of the PCC side voltage in the current operation mode is obtained, and a feedforward compensation power angle is determined based on the fault degree coefficient and the functional relation.
Preferably, wherein said determining a feedforward compensation power angle based on said fault extent coefficient and said functional relationship comprises:
when the fault degree coefficient is equal to 1, the rated current amplitude I is calculated N As the total output current amplitude of the grid-formed VSC, and combining the fault extent coefficient and the rated current amplitude I N Substituting the virtual power angle into the functional relation to obtain the virtual power angle at the moment as a feedforward compensation power angle;
When the failure degree coefficient is not equal to 1, the maximum current amplitude I is calculated max As the total output current amplitude of the grid-formed VSC and combining the fault extent coefficient and the maximum current amplitude I max Substituting the virtual power angle into the functional relation, and acquiring the virtual power angle at the moment as a feedforward compensation power angle.
In step 104, a transient feedforward active power is determined based on the feedforward compensation power angle, and the transient feedforward active power is feedforward to an active frequency control link of the network-structured VSC system to improve an input active power reference value, so as to realize coordinated control of transient stability and safety support capability of the network-structured VSC system.
Preferably, wherein said determining a transient feedforward active power based on said feedforward compensation power angle comprises:
wherein P is N * Is transient feedforward active power; ρ is a fault degree coefficient of the grid voltage; u (U) VSC And U N The voltage amplitude of the actual port and the rated voltage amplitude of the net-structured VSC system are respectively; p (P) N Rated power of the network-structured VSC system; delta F Compensating the power angle for feedforward; delta 0 Is a virtual power angle in the initial running state of the system.
In the invention, under the constraint of the transient stability and the maximum active supporting capacity based on the GFM-VSC system, a transient active power feedforward link is obtained, which is specifically as follows:
Step 3-1: detecting the fault degree of the PCC side voltage to obtain a fault degree coefficient rho;
step 3-2: based on the PCC side voltage fault degree, obtaining a feedforward compensation power angle delta F . Where, if ρ=1, no fault, ρ and rated current amplitude I N Substituting into formula (5) to obtain delta F Delta at this time F Is the virtual power angle delta in the initial running state of the system 0 The method comprises the steps of carrying out a first treatment on the surface of the If ρ is not equal to 1, a fault occurs, ρ is compared with the maximum current amplitude I max Substituting into formula (5) to obtain delta F Delta at this time F Delta is max ；
Step 3-3: delta to be obtained F Substituting the power into the following formula to obtain specific transient feedforward active power P N * The method comprises the following steps:
wherein: p (P) N * Is transient feedforward active power; u (U) VSC And U N The actual port voltage amplitude and the rated voltage amplitude of the GFM-VSC system are respectively; p (P) N Rated for GFM-VSC systems.
Step 3-4: the obtained transient feedforward active power P N * And the active frequency control link is fed forward to the GFM-VSC system, so that the input active power reference value is improved.
Finally, transient active power feedforward controlled by active frequency is adjusted through droop coefficients controlled by reactive voltage, so that a transient enhancement control module of the GFM-VSC is formed; after the control method is added to a typical GFM control scheme, the improved control method ensures the transient stability and safety of the GFM-VSC on the premise of maintaining the VCM characteristic, and simultaneously maximizes the active supporting capacity of the system to an external power grid.
The following specifically exemplifies embodiments of the present invention
In the present invention, the present invention will be described in further detail based on the network-structured VSC grid-connected system as shown in fig. 2 as an example. The system adopts a typical GFM control scheme based on virtual synchronous machine control and is additionally provided with a transient performance enhancement module. In said fig. 2: u (u) PCC ,i PCC PCC side voltage and current respectively; u (u) VSC ,i VSC The output voltage and current of the VSC; e is the internal potential of the VSC; i.e L For filteringInductor current; u (u) dc Is a direct current voltage; z is Z Line Impedance for line transmission; l (L) 1 ,R 1 C (C) 1 The parameters of the VSC output filter are respectively; c (C) dc The capacitor is a direct current bus capacitor; p (P) AC 、Q AC Active power and reactive power are output for the VSC respectively; p (P) T 、Q T Active and reactive power is transmitted for the line, respectively. The control system comprises an active frequency control link, a reactive voltage control link, a voltage current inner loop control link of an additional current limiting module and a PWM modulation link.
The invention provides an improved control method for coordinating transient stability, safety and supporting capacity of a GFM-VSC system, which comprises the following steps:
step 1: deriving a control equation of the GFM-VSC system and power injected through line impedance based on the topology structure and the control strategy of the GFM-VSC grid-connected system shown in FIG. 2;
Step 1-1: as shown in fig. 2, based on the control strategy of the GFM-VSC system, the control equation for deriving the GFM-VSC is as follows:
wherein: j (J) vir Is a virtual inertia coefficient; u (U) ref And omega ref The voltage reference amplitude and the virtual angular frequency are GFM-VSC; d (D) P And K is equal to P For damping and active frequency coefficients, respectively, an ac adjustment coefficient K is defined AC ＝K P +D P ；K Q Is the reactive voltage amplitude coefficient; p (P) N And omega g Rated power and PCC side angular frequency respectively; q (Q) N And U N Rated reactive power and voltage amplitude, respectively.
Step 1-2: considering that the voltage-current inner loop control response speed is far greater than the power outer loop control response speed, the port voltage actual value U of the GFM-VSC system can be set VSC Equal to the reference value U ref The method comprises the steps of carrying out a first treatment on the surface of the As shown in fig. 2, with the PCC side voltage as a reference, the system injects active power P into the grid through the line impedance T And reactive power Q T The method comprises the following steps:
wherein: u (U) PCC A PCC side PCC voltage magnitude; x is X L Is the line inductance; delta is the phase difference between the GFM-VSC port voltage and the PCC side voltage, and may be referred to as the virtual power angle.
Step 2: based on the maintenance of VCM capacity and transient safety constraint of the GFM-VSC system, an improved adjusting method for droop coefficients in reactive voltage control is deduced, and the method specifically comprises the following steps:
step 2-1: deriving a port voltage reference value of the GFM-VSC based on the foregoing step 1:
Step 2-2: based on the port voltage reference value obtained in the step 2-1, obtaining an inner ring dq axis output current of the GFM-VSC system under transient state as follows:
wherein: ρ is a grid voltage fault degree coefficient; c (C) 1 The filter capacitor is a GFM-VSC, and the value of the filter capacitor is smaller and negligible; i L,d And I L,q The current is output for the inner ring dq axis of the GFM-VSC system.
Step 2-3: based on the internal ring dq axis output current of the GFM-VSC system obtained in the step 2-2, the total output current amplitude I of the GFM-VSC can be obtained L The method comprises the following steps:
step 2-4: determining the initial value of the reactive voltage control loop parameter as K according to the steady-state operating point requirement and the allowable voltage fluctuation range of the system Q0 ,U N0 Q and N0 substituting the current into formula (5) to obtain the current amplitude distribution gauge of the GFM-VSC system under different voltage faults and different power angle positionsLaw, as shown in fig. 3.
In said fig. 3, it can be seen that the virtual power angle delta is for the total output current amplitude I L The influence of (a) becomes weaker with an increase in the failure degree coefficient ρ, and when the PCC-side voltage is recovered, the closer the position of δ is to 180 °, the I L The larger the value of (2), the easier it is to cross transient security constraints; considering that the overcurrent capability of the switching device is constant, the switching device can be controlled according to I L The droop coefficient of the reactive voltage control loop is adjusted to meet the requirements of transient safety and VCM (voltage control loop) characteristic maintenance of the system.
Step 2-5: k reduction Q The value of (2) is such that the GFM-VSC system always has a total output current amplitude I within the interval rho epsilon (0, 1) L Less than maximum current amplitude constraint I max The virtual power angle delta always has a solution in the following formula.
Change K Q From the values of (6), different K can be obtained Q The inner loop current magnitude satisfying the maximum current magnitude constraint is shown in FIG. 4, K in FIG. 4 (a) Q Taking infinity; k in FIG. 4 (b) Q =1.0 pu; k in (c) of FIG. 4 Q =0.8pu; k in (d) of FIG. 4 Q =0.6 pu. From FIG. 4, it can be seen that K Q Taking K Q0 I.e., 1.0pu, the GFM-VSC system cannot maintain VCM characteristics at voltage faults with ρ less than 0.1, regardless of how the δ position is changed. While reducing K Q After that, the system can meet the transient safety requirement and simultaneously has the capability of maintaining the VCM characteristics under any fault.
Step 2-6: constraint according to formula (6), obtaining the maximum sag coefficient K of the GFM-VSC system required to maintain VCM characteristics under transient state Q1 The method comprises the steps of carrying out a first treatment on the surface of the Initial value K of sagging coefficient of reactive voltage ring Q0 Adjust to K Q1 Therefore, the GFM-VSC is ensured to meet transient safety under large disturbance, and simultaneously has VCM characteristics all the time.
Step 3: based on the constraint of the transient stability and the maximized active supporting capacity of the GFM-VSC system, a transient active power feedforward link is obtained, as shown in fig. 5, specifically as follows:
Step 3-1: detecting the fault degree of the PCC side voltage to obtain a fault degree coefficient rho;
step 3-2: based on the PCC side voltage fault degree, obtaining a feedforward compensation power angle delta F . If ρ=1, then there is no fault, ρ is compared with the rated current amplitude I N Substituting into formula (5) to obtain delta at this time F Delta is 0 The method comprises the steps of carrying out a first treatment on the surface of the If ρ is not equal to 1, a fault occurs, ρ is compared with the maximum current amplitude I max Substituting into formula (5) to obtain delta at this time F Delta is max 。
Step 3-3: will delta F Substituting the power into the following formula to obtain specific transient feedforward active power P N * The method comprises the following steps:
wherein: p (P) N * Is transient feedforward active power; u (U) VSC And U N The actual port voltage amplitude and the rated voltage amplitude of the GFM-VSC system are respectively; p (P) N Rated for GFM-VSC systems.
Step 3-4: the obtained transient feedforward active power P N * For an active frequency control link fed forward to the GFM-VSC system, improving an input active power reference value;
step 4: finally, transient active power feedforward controlled by the active frequency and the droop coefficient of the reactive voltage control are respectively adjusted to form a transient enhancement control module of the GFM-VSC, as shown in a dotted line frame in the figure 1; the method ensures the transient stability and safety of the GFM-VSC under the premise of maintaining the VCM characteristic, and simultaneously maximizes the active supporting capacity of the system to an external power grid.
The specific simulation waveforms are shown in fig. 6, 7 and 8, the simulation working conditions are set as that the PCC side voltage has three-phase voltage sag faults at 0.3s, the faults are cleared at 0.4s, the amplitude of the PCC side voltage is recovered, and the transient response of the GFM-VSC system in the whole disturbance process is analyzed.
Said FIG. 6 shows the transient response waveform of the GFM-VSC system without clippingThe port voltage and PCC side voltage magnitudes, the transmitted active and reactive power, the virtual power angle and output current magnitudes, and the corresponding dq axis current components, respectively. As can be seen from said fig. 6, the GFM-VSC output current amplitude has exceeded the maximum current amplitude I during the fault duration max At the same time the current amplitude at the moment of fault clearing reaches I max Is 2 times less than the transient safety constraint of the system.
The transient response waveforms of the GFM-VSC system in the additional d-axis current priority clipping step are shown in fig. 7, which are the port voltage and PCC side voltage amplitudes, the transmitted active and reactive power, the virtual power angle and output current amplitudes, and the corresponding dq-axis current components, respectively. As can be seen from the above-mentioned fig. 7, the fault duration triggers the current limiting link, and although the port current of the GFM-VSC system is limited to meet the transient safety requirement, the port voltage drops rapidly, and the VCM characteristic cannot be maintained for active support; meanwhile, after the fault is cleared, the GFM-VSC cannot autonomously exit from the amplitude limiting mode, so that the system is in transient instability.
Said fig. 8 shows the transient response waveforms of the GFM-VSC system under the proposed improved control method, respectively the port voltage and PCC side voltage amplitudes, the transmitted active and reactive power, the virtual power angle and output current amplitudes and the corresponding dq-axis current components. As can be seen from said fig. 8, during the duration of the fault, the GFM-VSC is able to maintain VCM mode while the output current is Imax, maximizing the active support capacity of the GFM-VSC system while meeting the transient safety constraints; after the fault is cleared, the system can be quickly recovered, and has better transient stability.
Fig. 9 is a schematic structural diagram of a coordinated control system 900 of transient stability and safety support capability of a networked VSC system according to an embodiment of the present invention. As shown in fig. 9, a coordinated control system 900 for transient stability and safety support capability of a network VSC system according to an embodiment of the present invention includes: a functional relation determining unit 901, a droop coefficient adjusting unit 902, a feedforward compensation power angle determining unit 903 and a feedforward control unit 904.
Preferably, the functional relation determining unit 901 is configured to determine a functional relation between the total output current amplitude and the reactive voltage control link parameter of the grid-formed VSC system.
Preferably, wherein the functional relationship comprises:
wherein I is L The total output current amplitude for the grid-formed VSC; i L,d And I L,q Outputting current for an inner ring dq axis of the network-structured VSC system; ρ is a fault degree coefficient of the grid voltage; delta is a virtual power angle; k (K) Q Is a sagging coefficient; q (Q) N And U N Rated reactive power and voltage amplitude respectively; c (C) 1 A filter capacitor which is GFM-VSC; u (U) PCC A PCC side PCC voltage magnitude; x is X L Is the line inductance; omega is fundamental voltage reference angular frequency; delta is the intermediate quantity; u (U) ref The voltage reference amplitude for a grid-type VSC.
Preferably, the droop coefficient adjustment unit 902 is configured to determine a constraint condition based on the functional relation and the maximum current amplitude, determine a maximum droop coefficient of the transient-state grid-formed VSC system capable of maintaining the voltage source control mode based on the constraint condition, and adjust the droop coefficient based on the maximum droop coefficient.
Preferably, wherein the constraint comprises:
wherein I is L The total output current amplitude for the grid-formed VSC; i L,d And I L,q Inner ring dq axis for a grid-built VSC systemOutputting a current; ρ is a fault degree coefficient of the grid voltage; delta is a virtual power angle; k (K) Q Is a sagging coefficient; q (Q) N And U N Rated reactive power and voltage amplitude respectively; i max Is the maximum current amplitude; wherein by lowering K Q In such a way that the net VSC system always has a total output current amplitude I within the interval ρ ε (0, 1) L Less than maximum current amplitude constraint I max The maximum sagging coefficient is determined on the premise that the virtual power angle delta always has a solution.
Preferably, the feedforward compensation power angle determining unit 903 is configured to obtain a fault degree coefficient of the PCC side voltage in the current operation mode, and determine the feedforward compensation power angle based on the fault degree coefficient and the functional relationship.
Preferably, the feedforward compensation power angle determining unit 903 determines a feedforward compensation power angle based on the fault degree coefficient and the functional relation, including:
when the fault degree coefficient is equal to 1, the rated current amplitude I is calculated N As the total output current amplitude of the grid-formed VSC, and combining the fault extent coefficient and the rated current amplitude I N Substituting the virtual power angle into the functional relation to obtain the virtual power angle at the moment as a feedforward compensation power angle;
when the failure degree coefficient is not equal to 1, the maximum current amplitude I is calculated max As the total output current amplitude of the grid-formed VSC and combining the fault extent coefficient and the maximum current amplitude I max Substituting the virtual power angle into the functional relation, and acquiring the virtual power angle at the moment as a feedforward compensation power angle.
Preferably, the feedforward control unit 904 is configured to determine a transient feedforward active power based on the feedforward compensation power angle, and feedforward the transient feedforward active power to an active frequency control link of the network VSC system, so as to improve an input active power reference value, and realize coordinated control of transient stability and safety support capability of the network VSC system.
Preferably, wherein the feedforward control unit 904 determines a transient feedforward active power based on the feedforward compensation power angle, including:
wherein P is N * Is transient feedforward active power; ρ is a fault degree coefficient of the grid voltage; u (U) VSC And U N The voltage amplitude of the actual port and the rated voltage amplitude of the net-structured VSC system are respectively; p (P) N Rated power of the network-structured VSC system; delta F Compensating the power angle for feedforward; delta 0 Is a virtual power angle in the initial running state of the system.
The coordinated control system 900 of the transient stability and safety support capability of the grid-configured VSC system according to the embodiment of the present invention corresponds to the coordinated control method 100 of the transient stability and safety support capability of the grid-configured VSC system according to another embodiment of the present invention, and will not be described herein.
Based on another aspect of the present invention, there is provided a computer readable storage medium having stored thereon a computer program which when executed by a processor implements the steps of any one of the methods for coordinated control of transient stability and safe support capabilities of a networked VSC system.
Based on another aspect of the present invention, the present invention provides an electronic device, including:
the computer readable storage medium as described above; and
one or more processors configured to execute the programs in the computer-readable storage medium.
The invention has been described with reference to a few embodiments. However, as is well known to those skilled in the art, other embodiments than the above disclosed invention are equally possible within the scope of the invention, as defined by the appended patent claims.
Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise therein. All references to "a/an/the [ means, component, etc. ]" are to be interpreted openly as referring to at least one instance of said means, component, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.
It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: the above embodiments are only for illustrating the technical aspects of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those of ordinary skill in the art that: modifications and equivalents may be made to the specific embodiments of the invention without departing from the spirit and scope of the invention, which is intended to be covered by the claims.
Claims (12)
1. A method for coordinated control of transient stability and safety support capability of a networked VSC system, the method comprising:
determining a functional relation between the total output current amplitude of the network-structured VSC system and reactive voltage control link parameters;
determining a constraint condition based on the functional relation and the maximum current amplitude, determining a maximum droop coefficient of the transient grid-formed VSC system capable of maintaining a voltage source control mode based on the constraint condition, and adjusting the droop coefficient based on the maximum droop coefficient;
obtaining a fault degree coefficient of PCC side voltage in a current operation mode, and determining a feedforward compensation power angle based on the fault degree coefficient and the functional relation;
and determining transient feedforward active power based on the feedforward compensation power angle, and feedforward the transient feedforward active power to an active frequency control link of the network-structured VSC system to improve an input active power reference value so as to realize coordinated control of transient stability and safety supporting capacity of the network-structured VSC system.
2. The method of claim 1, wherein the functional relationship comprises:
wherein I is L The total output current amplitude for the grid-formed VSC; i L,d And I L,q Outputting current for an inner ring dq axis of the network-structured VSC system; ρ is a fault degree coefficient of the grid voltage; delta is a virtual power angle; k (K) Q Is a sagging coefficient; q (Q) N And U N Rated reactive power and voltage amplitude respectively; c (C) 1 A filter capacitor which is GFM-VSC; u (U) PCC A PCC side PCC voltage magnitude; x is X L Is the line inductance; omega is fundamental voltage reference angular frequency; delta is an intermediate quantity. The method comprises the steps of carrying out a first treatment on the surface of the U (U) ref The voltage reference amplitude for a grid-type VSC.
3. The method of claim 1, wherein the constraint comprises:
wherein I is L The total output current amplitude for the grid-formed VSC; i L,d And I L,q Outputting current for an inner ring dq axis of the network-structured VSC system; ρ is a fault degree coefficient of the grid voltage; delta is a virtual power angle; k (K) Q Is a sagging coefficient; q (Q) N And U N Rated reactive power and voltage amplitude respectively; i max Is the maximum current amplitude; wherein by lowering K Q In such a way that the net VSC system always has a total output current amplitude I within the interval ρ ε (0, 1) L Less than maximum current amplitude constraint I max The range of the power angle, i.eAnd on the premise that the virtual power angle delta always has a solution, determining the maximum sagging coefficient.
4. The method of claim 1, wherein the determining a feedforward compensation power angle based on the fault level coefficient and the functional relationship comprises:
When the fault degree coefficient is equal to 1, the rated current amplitude I is calculated N As the total output current amplitude of the grid-formed VSC, and combining the fault extent coefficient and the rated current amplitude I N Substituting the virtual power angle into the functional relation to obtain the virtual power angle at the moment as a feedforward compensation power angle;
when the failure degree coefficient is not equal to 1, the maximum current amplitude I is calculated max As the total output current amplitude of the grid-formed VSC and combining the fault extent coefficient and the maximum current amplitude I max Substituting the virtual power angle into the functional relation, and acquiring the virtual power angle at the moment as a feedforward compensation power angle.
5. The method of claim 1, wherein the determining a transient feedforward active power based on the feedforward compensation power angle comprises:
wherein P is N * Is transient feedforward active power; ρ is a fault degree coefficient of the grid voltage; u (U) VSC And U N The voltage amplitude of the actual port and the rated voltage amplitude of the net-structured VSC system are respectively; p (P) N Rated power of the network-structured VSC system; delta F Compensating the power angle for feedforward; delta 0 Is a virtual power angle in the initial running state of the system.
6. A coordinated control system for transient stability and safety support capability of a networked VSC system, the system comprising:
The function relation determining unit is used for determining a function relation between the total output current amplitude of the network-structured VSC system and reactive voltage control link parameters;
a droop coefficient adjustment unit, configured to determine a constraint condition based on the functional relationship and a maximum current amplitude, determine a maximum droop coefficient of a transient-state grid-formed VSC system capable of maintaining a voltage source control mode based on the constraint condition, and adjust the droop coefficient based on the maximum droop coefficient;
the feedforward compensation power angle determining unit is used for obtaining a fault degree coefficient of the PCC side voltage in the current operation mode and determining a feedforward compensation power angle based on the fault degree coefficient and the functional relation;
and the feedforward control unit is used for determining transient feedforward active power based on the feedforward compensation power angle, and feedforward the transient feedforward active power to an active frequency control link of the network-structured VSC system so as to improve an input active power reference value and realize coordination control of transient stability and safety supporting capacity of the network-structured VSC system.
7. The system of claim 6, wherein the functional relationship comprises:
wherein I is L The total output current amplitude for the grid-formed VSC; i L,d And I L,q Outputting current for an inner ring dq axis of the network-structured VSC system; ρ is a fault degree coefficient of the grid voltage; delta is a virtual power angle; k (K) Q Is a sagging coefficient; q (Q) N And U N Respectively rated reactive powerA voltage amplitude; c (C) 1 A filter capacitor which is GFM-VSC; u (U) PCC A PCC side PCC voltage magnitude; x is X L Is the line inductance; omega is fundamental voltage reference angular frequency; delta is the intermediate quantity; u (U) ref The voltage reference amplitude for a grid-type VSC.
8. The system of claim 6, wherein the constraint comprises:
wherein I is L The total output current amplitude for the grid-formed VSC; i L,d And I L,q Outputting current for an inner ring dq axis of the network-structured VSC system; ρ is a fault degree coefficient of the grid voltage; delta is a virtual power angle; k (K) Q Is a sagging coefficient; q (Q) N And U N Rated reactive power and voltage amplitude respectively; i max Is the maximum current amplitude; wherein by lowering K Q In such a way that the net VSC system always has a total output current amplitude I within the interval ρ ε (0, 1) L Less than maximum current amplitude constraint I max The maximum sagging coefficient is determined on the premise that the virtual power angle delta always has a solution.
9. The system according to claim 6, wherein the feedforward compensation power angle determination unit that determines the feedforward compensation power angle based on the failure degree coefficient and the functional relationship includes:
When the fault degree coefficient is equal to 1, the rated current amplitude I is calculated N As the total output current amplitude of the grid-formed VSC, and combining the fault extent coefficient and the rated current amplitude I N Substituting the virtual power angle into the functional relation to obtain the virtual power angle at the moment as a feedforward compensation power angle;
when the failure degree coefficient is not equal to 1, the maximum current amplitude I is calculated max As the total output current amplitude of the grid-formed VSC and tying the degree of failureNumber and maximum current amplitude I max Substituting the virtual power angle into the functional relation, and acquiring the virtual power angle at the moment as a feedforward compensation power angle.
10. The system of claim 6, wherein the feedforward control unit determines a transient feedforward active power based on the feedforward compensation power angle, comprising:
wherein P is N * Is transient feedforward active power; ρ is a fault degree coefficient of the grid voltage; u (U) VSC And U N The voltage amplitude of the actual port and the rated voltage amplitude of the net-structured VSC system are respectively; p (P) N Rated power of the network-structured VSC system; delta F Compensating the power angle for feedforward; delta 0 Is a virtual power angle in the initial running state of the system.
11. A computer readable storage medium, on which a computer program is stored, characterized in that the program, when being executed by a processor, implements the steps of the method according to any of claims 1-5.
12. An electronic device, comprising:
the computer readable storage medium recited in claim 11; and
one or more processors configured to execute the programs in the computer-readable storage medium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310049853.3A CN116131366B (en) | 2023-02-01 | 2023-02-01 | Coordinated control method for transient stability and safe supporting capacity of network-structured VSC system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310049853.3A CN116131366B (en) | 2023-02-01 | 2023-02-01 | Coordinated control method for transient stability and safe supporting capacity of network-structured VSC system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116131366A true CN116131366A (en) | 2023-05-16 |
| CN116131366B CN116131366B (en) | 2024-07-19 |
Family
ID=86311305
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310049853.3A Active CN116131366B (en) | 2023-02-01 | 2023-02-01 | Coordinated control method for transient stability and safe supporting capacity of network-structured VSC system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116131366B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105356783A (en) * | 2015-10-28 | 2016-02-24 | 浙江大学 | Enhanced current-limiting control method aimed at drop-controlled inverter |
| CN108376986A (en) * | 2018-03-30 | 2018-08-07 | 海南电网有限责任公司文昌供电局 | Electric distribution network reactive-voltage control method and device |
| CN108418223A (en) * | 2017-04-27 | 2018-08-17 | 广东电网有限责任公司佛山供电局 | Active distribution network reactive voltage coordinated operation optimization method and system |
| CN110601221A (en) * | 2019-06-17 | 2019-12-20 | 湖南大学 | Voltage stability control method for connecting multi-voltage source type converter to medium-voltage direct-current system |
| US20200335978A1 (en) * | 2019-04-16 | 2020-10-22 | Xi'an University Of Technology | Adaptive Control Method for Output Feedback of Virtual Synchronous Generator |
| CN112542835A (en) * | 2020-12-08 | 2021-03-23 | 东南大学 | Multi-level control method for AC/DC hybrid micro-grid with high-proportion photovoltaic access |
| CN113541156A (en) * | 2021-06-28 | 2021-10-22 | 国网上海市电力公司 | Reactive voltage adjusting method based on reactor compensation device |
| CN115189424A (en) * | 2022-08-04 | 2022-10-14 | 湖南大学 | Coordination optimization configuration method for alternating current net rack and synchronous phase modulator |
| CN115579901A (en) * | 2022-10-18 | 2023-01-06 | 国网浙江省电力有限公司电力科学研究院 | Method and system for analyzing static voltage stability of LCC-HVDC receiving-end power grid |
| CN115586397A (en) * | 2022-09-26 | 2023-01-10 | 东南大学 | Active power distribution network fault distinguishing method, equipment and storage medium |
-
2023
- 2023-02-01 CN CN202310049853.3A patent/CN116131366B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105356783A (en) * | 2015-10-28 | 2016-02-24 | 浙江大学 | Enhanced current-limiting control method aimed at drop-controlled inverter |
| CN108418223A (en) * | 2017-04-27 | 2018-08-17 | 广东电网有限责任公司佛山供电局 | Active distribution network reactive voltage coordinated operation optimization method and system |
| CN108376986A (en) * | 2018-03-30 | 2018-08-07 | 海南电网有限责任公司文昌供电局 | Electric distribution network reactive-voltage control method and device |
| US20200335978A1 (en) * | 2019-04-16 | 2020-10-22 | Xi'an University Of Technology | Adaptive Control Method for Output Feedback of Virtual Synchronous Generator |
| CN110601221A (en) * | 2019-06-17 | 2019-12-20 | 湖南大学 | Voltage stability control method for connecting multi-voltage source type converter to medium-voltage direct-current system |
| CN112542835A (en) * | 2020-12-08 | 2021-03-23 | 东南大学 | Multi-level control method for AC/DC hybrid micro-grid with high-proportion photovoltaic access |
| CN113541156A (en) * | 2021-06-28 | 2021-10-22 | 国网上海市电力公司 | Reactive voltage adjusting method based on reactor compensation device |
| CN115189424A (en) * | 2022-08-04 | 2022-10-14 | 湖南大学 | Coordination optimization configuration method for alternating current net rack and synchronous phase modulator |
| CN115586397A (en) * | 2022-09-26 | 2023-01-10 | 东南大学 | Active power distribution network fault distinguishing method, equipment and storage medium |
| CN115579901A (en) * | 2022-10-18 | 2023-01-06 | 国网浙江省电力有限公司电力科学研究院 | Method and system for analyzing static voltage stability of LCC-HVDC receiving-end power grid |
Non-Patent Citations (3)
| Title |
|---|
| XIAOSHUN GUO: "Transient Stability Analysis and Controller Optimization of Grid-Connected Converter Under Input Power Variation", 2021 INTERNATIONAL CONFERENCE ON POWER SYSTEM TECHNOLOGY (POWERCON), 8 February 2022 (2022-02-08) * |
| 曾琦;李兴源;张立奎;邓旗;: "VSC-HVDC互联系统电压稳定控制策略", 工程科学与技术, no. 04, 20 July 2017 (2017-07-20) * |
| 黄林彬;辛焕海;鞠平;胡家兵;: "电力电子并网装备的同步稳定分析与统一同步控制结构", 电力自动化设备, no. 09, 4 September 2020 (2020-09-04) * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116131366B (en) | 2024-07-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109149620B (en) | Self-energy-storage multi-terminal flexible-straight system control method and system | |
| US20120112551A1 (en) | Intelligent power converter control for grid integration of renewable energies | |
| CN105356783B (en) | A kind of enhanced Current limited Control method for droop control inverter | |
| Chawda et al. | Power quality improvement in rural grid using adaptive control algorithm to enhance wind energy penetration levels | |
| EP4123896B1 (en) | Control method of three-phase multi-level inverter and inverter system | |
| CN109736870A (en) | Underground Local Fan wind speed adjusting method based on modified auto-disturbance rejection technology | |
| CN115102149A (en) | Overcurrent suppression system and method for network type converter | |
| CN115021277A (en) | Control method and system for improving damping characteristic of new energy through flexible direct current transmission | |
| CN109888776A (en) | For the prediction technique and terminal device of direct-driving type wind power plant subsynchronous resonance frequency | |
| CN115051404A (en) | Alternating voltage control method of high-voltage network-building type current converter | |
| CN116131366B (en) | Coordinated control method for transient stability and safe supporting capacity of network-structured VSC system | |
| CN111244958A (en) | Closed-loop global synchronous pulse width modulation method based on cyclic disturbance observation | |
| CN115378036A (en) | Emergency control method and device considering VSG current limitation and transient stability | |
| CN116345483A (en) | Voltage source type wind turbine generator oscillation suppression and parameter optimization method | |
| Guofei et al. | A control method with grid disturbances suppression for a single-phase LCL-filter-based grid-connected inverter | |
| CN116014692B (en) | Network-structured VSC fault current suppression method based on voltage vector dynamic tracking control | |
| CN113964837A (en) | Composite control method and system suitable for LCL type parallel active power filter | |
| CN112596376A (en) | Synchronous phase modulator excitation system optimization control method based on variable-discourse-domain fuzzy self-adaptive PID control | |
| Haro-Larrode et al. | Analysis of voltage dynamics within current control time-scale in a VSC connected to a weak AC grid via series compensated AC line | |
| CN115800340B (en) | Amplitude limiting control method and system for enhancing transient stability of network-structured VSC | |
| CN110867890B (en) | Step-falling slamming-slamming control method for double-fed fan direct-current bus voltage | |
| CN113241802B (en) | Microgrid grid-connected point voltage control system and method based on power cooperative regulation | |
| CN113595066B (en) | Method for restraining ultralow frequency oscillation of water-light complementary system based on additional controller | |
| CN114938006B (en) | Virtual inertia-based power grid frequency control method and system | |
| CN118137573B (en) | New energy grid-connected stable control method, system, electronic equipment and storage medium |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |