CN116865361A - Virtual synchronous generator power control method based on fractional differentiation - Google Patents
Virtual synchronous generator power control method based on fractional differentiation Download PDFInfo
- Publication number
- CN116865361A CN116865361A CN202310894839.3A CN202310894839A CN116865361A CN 116865361 A CN116865361 A CN 116865361A CN 202310894839 A CN202310894839 A CN 202310894839A CN 116865361 A CN116865361 A CN 116865361A
- Authority
- CN
- China
- Prior art keywords
- synchronous generator
- virtual synchronous
- power
- virtual
- output
- 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
- 230000001360 synchronised effect Effects 0.000 title claims abstract description 63
- 238000000034 method Methods 0.000 title claims abstract description 20
- 230000004069 differentiation Effects 0.000 title claims abstract description 10
- 238000004364 calculation method Methods 0.000 claims description 10
- 230000009466 transformation Effects 0.000 claims description 6
- 238000005070 sampling Methods 0.000 claims description 3
- 230000010355 oscillation Effects 0.000 abstract description 7
- 230000004044 response Effects 0.000 abstract description 7
- 230000007547 defect Effects 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 4
- 238000013016 damping Methods 0.000 description 3
- 230000001629 suppression Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
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
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Eletrric Generators (AREA)
Abstract
The invention discloses a virtual synchronous generator power control method based on fractional order differentiation, and belongs to the technical field of virtual synchronous generator control. According to the invention, a fractional differential compensation link is connected in series on a forward channel of the VSG system, so that fractional differential control can be introduced, and the response of the system to power fluctuation is improved; the fractional differential compensation can better inhibit the power oscillation which changes rapidly, and improve the stability and response speed of the system; the method overcomes the defect of insufficient inertia of a first-order virtual inertia strategy in an initial response stage based on differential compensation while ensuring the steady-state control performance of power and reducing the overshoot of dynamic power.
Description
Technical Field
The invention relates to the technical field of virtual synchronous generator control, in particular to a virtual synchronous generator power control method based on fractional order differentiation.
Background
A virtual synchronous generator (Virtual Synchronous Generator, VSG) is an inverter-based power conversion system that mimics the operating characteristics of a conventional synchronous generator for interconnecting distributed power resources with a power network. The virtual synchronous generator is additionally provided with a fractional differential link on a forward channel of angular frequency closed-loop control of first-order virtual inertia, so that the method not only increases the system damping, but also effectively reduces the power overshoot in the dynamic process while ensuring the steady-state control performance of the virtual synchronous generator, and realizes higher-quality power injection and system stability.
The existing VSG based on the first-order virtual inertia can inhibit frequency fluctuation, but due to the fact that overload capacity of a power electronic device is weak, when a virtual inertia rotation value is designed to be large, active power instructions or load abrupt changes can cause active power output by the VSG in a dynamic process to generate large overshoot or low-frequency oscillation, so that an energy storage unit is subjected to large power impact, and the VSG triggers over-current protection. Although the increase of the damping coefficient can inhibit the overshoot of active power or low-frequency oscillation, the VSG grid-connected steady-state power deviation and the grid-connected steady-state power sharing precision are increased, and the problems are to be solved.
Disclosure of Invention
The technical problems to be solved by the invention are as follows: how to solve the problem that the dynamic and static characteristics of active output power cannot be considered when the virtual synchronous generator is in grid-connected operation, the power control method of the virtual synchronous generator based on fractional differentiation is provided, and the shortcomings of inertia shortage of a first-order virtual inertia strategy based on differential compensation in an initial response stage are overcome while ensuring the power steady-state control performance and reducing the dynamic power overshoot.
The invention solves the technical problems through the following technical proposal, and the invention comprises the following steps:
s1: sampling three-phase output voltage u of virtual synchronous generator a 、u b 、u c And three-phase inductance current i a 、i b 、i c And respectively obtaining the dq axis component u of the output voltage through single synchronous rotation coordinate transformation d 、u q And an inductor current dq axis component i d 、i q Wherein the d axis is an active axis, and the q axis is a reactive axis;
s2: based on the output voltage dq axis component u obtained in step S1 d 、u q And an inductor current dq axis component i d 、i q Obtain the output average active power P out ；
S3: outputting active power P from the virtual synchronous generator obtained in the step S2 out Integrating through virtual inertia link and adding rated angular frequency omega n An output angular frequency ω as a virtual synchronous generator;
s4: integrating the output angular frequency omega of the virtual synchronous generator obtained in the step S3 to obtain an output phase angle delta of the virtual synchronous generator;
s5: modulating the amplitude u of the voltage modulation waves of the d axis and the q axis of the virtual synchronous generator d 、u q And S4, obtaining a three-phase modulation wave of the bridge arm voltage by carrying out inverse transformation on the output phase angle delta obtained in the step through single synchronous rotation coordinates, and modulating the three-phase modulation wave to be used as a driving signal of the IGBT circuit.
Further, in step S2, an average active power P is output out The calculation formula is as follows:
further, in the step S3, the calculation formula of the output angular frequency ω of the virtual synchronous generator is:
wherein K is d The differential element coefficient is S is a fractional differential element, a is a fractional order coefficient, J is virtual moment of inertia, D is virtual damping, P ref An active power command is given for the virtual synchronous generator.
Further, in step S4, the calculation formula of the output phase angle δ of the virtual synchronous generator is:
compared with the prior art, the invention has the following advantages: according to the fractional differential-based virtual synchronous generator power control method, a fractional differential compensation link is connected in series on a forward channel of a VSG system, so that fractional differential control can be introduced, and the response of the system to power fluctuation is improved; the fractional differential compensation can better inhibit the power oscillation which changes rapidly, and improve the stability and response speed of the system.
Drawings
FIG. 1 is a schematic diagram of a main circuit and control structure of a virtual synchronous generator according to an embodiment of the present invention;
FIG. 2 is a control block diagram of a method of virtual synchronous generator power stabilization in an embodiment of the invention;
FIG. 3 is a graph comparing the power oscillation suppression of a virtual synchronous generator designed according to the present invention and a conventional virtual synchronous generator in an embodiment of the present invention;
FIG. 4 shows the differential link coefficient K of the present invention in an embodiment of the present invention d Schematic of the impact on power;
fig. 5 is a schematic diagram showing the influence of fractional order coefficient a of the present invention on power in the embodiment of the present invention.
Detailed Description
The following describes in detail the examples of the present invention, which are implemented on the premise of the technical solution of the present invention, and detailed embodiments and specific operation procedures are given, but the scope of protection of the present invention is not limited to the following examples.
As shown in fig. 1, in the embodiment, the main circuit and the control structure of the virtual synchronous generator are shown, the direct current source is powered by the distributed power source, two output ends of the direct current source are respectively connected with two input ends of the three-phase bridge arm, and three output ends of the three-phase bridge arm are connected with the LC filterThe three-phase inputs of the wave device are correspondingly connected. L (L) f Filter inductance of LC filter, C f Is the filter capacitance of the LC filter, R f Is the resistance of the LC filter. i.e L a，i L b，i L c is three-phase inductance current of virtual synchronous generator, u a ，u b ，u c Is the three-phase output voltage of the virtual synchronous generator.
The module 1 is a power calculation module which collects the voltage and the current of the public coupling point of the main circuit module 5 to calculate active power and reactive power; the module 2 is a virtual synchronous generator module; the module 3 is a voltage and current double closed-loop control module and plays a decoupling role; the module 4 is a PWM wave generation module. The module 5 is a main circuit module.
As shown in fig. 2, a control block diagram of a power stabilizing method of a virtual synchronous generator in this embodiment is shown, and the main steps of the control method of the present invention are as follows:
step 1, sampling three-phase output voltage u of virtual synchronous generator a 、u b 、u c And three-phase inductance current i a 、i b 、i c And respectively obtaining the dq axis component u of the output voltage through single synchronous rotation coordinate transformation d 、u q And an inductor current dq axis component i d 、i q Wherein the d axis is an active axis, and the q axis is a reactive axis;
step 2, based on the output voltage dq axis component u obtained in step 1 d 、u q And an inductor current dq axis component i d 、i q Obtain the output average active power P out 。
Output average active power P out The calculation formula is as follows:
step 3, outputting active power P from the virtual synchronous generator obtained in the step 2 out Integrating through virtual inertia link and adding rated angular frequency omega n As the output angular frequency ω of the virtual synchronous generator, the calculation formula is as follows:
wherein K is d The differential element coefficient is S is a fractional differential element, a is a fractional order coefficient, J is virtual moment of inertia, D is virtual damping, P ref An active power command is given for the virtual synchronous generator.
And 4, integrating the output angular frequency omega of the virtual synchronous generator obtained in the step 3 to obtain an output phase angle delta of the virtual synchronous generator, wherein a calculation formula of the output phase angle delta of the virtual synchronous generator is as follows:
step 5, modulating the amplitude u of the d-axis and q-axis voltage of the virtual synchronous generator d 、u q And (4) obtaining a three-phase modulation wave of the bridge arm voltage by carrying out inverse transformation on the output phase angle delta obtained in the step (4) through single synchronous rotation coordinates, and modulating the three-phase modulation wave to be used as a driving signal of the IGBT circuit.
The invention is applicable to the distributed power inverter adopting the virtual synchronous generator algorithm.
As shown in fig. 4, the virtual synchronous generator parameter K designed for the present invention d The influence on the power is schematically shown, and K can be seen d The larger the power oscillation suppression is, the better.
As shown in fig. 5, the influence of the fractional order coefficient a of the virtual synchronous generator designed by the invention on the power is shown schematically, and it can be seen that the larger the value of a is, the better the suppression of the power oscillation is.
In summary, in the method for controlling the power of the virtual synchronous generator based on fractional differentiation according to the embodiment, the damping ratio of the system is increased, the dynamic response speed is accelerated, and the power impact of power overshoot is suppressed while maintaining the steady-state active power control precision and the steady-state active power average characteristic.
While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.
Claims (4)
1. The virtual synchronous generator power control method based on fractional differentiation is characterized by comprising the following steps of:
s1: sampling three-phase output voltage u of virtual synchronous generator a 、u b 、u c And three-phase inductance current i a 、i b 、i c And respectively obtaining the dq axis component u of the output voltage through single synchronous rotation coordinate transformation d 、u q And an inductor current dq axis component i d 、i q Wherein the d axis is an active axis, and the q axis is a reactive axis;
s2: based on the output voltage dq axis component u obtained in step S1 d 、u q And an inductor current dq axis component i d 、i q Obtain the output average active power P out ；
S3: outputting active power P from the virtual synchronous generator obtained in the step S2 out Integrating through virtual inertia link and adding rated angular frequency omega n An output angular frequency ω as a virtual synchronous generator;
s4: integrating the output angular frequency omega of the virtual synchronous generator obtained in the step S3 to obtain an output phase angle delta of the virtual synchronous generator;
s5: modulating the amplitude u of the voltage modulation waves of the d axis and the q axis of the virtual synchronous generator d 、u q And S4, obtaining a three-phase modulation wave of the bridge arm voltage by carrying out inverse transformation on the output phase angle delta obtained in the step through single synchronous rotation coordinates, and modulating the three-phase modulation wave to be used as a driving signal of the IGBT circuit.
2. The method for controlling power of a virtual synchronous generator based on fractional differentiation according to claim 1, wherein: in step S2, the average active power P is output out The calculation formula is as follows:
3. the method for controlling the power of the virtual synchronous generator based on fractional differentiation according to claim 2, wherein the method comprises the following steps: in the step S3, a calculation formula of the output angular frequency ω of the virtual synchronous generator is:
wherein K is d The differential element coefficient is S is a fractional differential element, a is a fractional order coefficient, J is virtual moment of inertia, D is virtual damping, P ref An active power command is given for the virtual synchronous generator.
4. A method of controlling power of a virtual synchronous generator based on fractional differentiation as described in claim 3, wherein: in step S4, the calculation formula of the virtual synchronous generator output phase angle δ is:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310894839.3A CN116865361A (en) | 2023-07-20 | 2023-07-20 | Virtual synchronous generator power control method based on fractional differentiation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310894839.3A CN116865361A (en) | 2023-07-20 | 2023-07-20 | Virtual synchronous generator power control method based on fractional differentiation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116865361A true CN116865361A (en) | 2023-10-10 |
Family
ID=88218914
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310894839.3A Pending CN116865361A (en) | 2023-07-20 | 2023-07-20 | Virtual synchronous generator power control method based on fractional differentiation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116865361A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107104447A (en) * | 2017-05-12 | 2017-08-29 | 合肥工业大学 | Virtual synchronous generator control method based on second order broad sense virtual inertia |
| US20180145582A1 (en) * | 2017-01-16 | 2018-05-24 | Hunan University | Virtual synchronous inverter with fast transient inrush fault currents restraining method thereof |
| CN109656140A (en) * | 2018-12-28 | 2019-04-19 | 三峡大学 | A kind of fractional order differential offset-type VSG control method |
| CN111953026A (en) * | 2020-07-12 | 2020-11-17 | 国网江苏省电力有限公司南京供电分公司 | Virtual synchronous generator control method and system based on second-order response voltage compensation |
| WO2023083128A1 (en) * | 2021-11-11 | 2023-05-19 | 广东志成冠军集团有限公司 | Island microgrid system, and interactive oscillation suppression method and system therefor |
-
2023
- 2023-07-20 CN CN202310894839.3A patent/CN116865361A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20180145582A1 (en) * | 2017-01-16 | 2018-05-24 | Hunan University | Virtual synchronous inverter with fast transient inrush fault currents restraining method thereof |
| CN107104447A (en) * | 2017-05-12 | 2017-08-29 | 合肥工业大学 | Virtual synchronous generator control method based on second order broad sense virtual inertia |
| CN109656140A (en) * | 2018-12-28 | 2019-04-19 | 三峡大学 | A kind of fractional order differential offset-type VSG control method |
| CN111953026A (en) * | 2020-07-12 | 2020-11-17 | 国网江苏省电力有限公司南京供电分公司 | Virtual synchronous generator control method and system based on second-order response voltage compensation |
| WO2023083128A1 (en) * | 2021-11-11 | 2023-05-19 | 广东志成冠军集团有限公司 | Island microgrid system, and interactive oscillation suppression method and system therefor |
Non-Patent Citations (1)
| Title |
|---|
| 屈子森;蔡云旖;杨欢;董宁波;赵荣祥;韩俊飞;: "基于自适应虚拟阻抗的虚拟同步机功率解耦控制策略", 电力***自动化, no. 17 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ouchen et al. | Direct power control of shunt active power filter using space vector modulation based on supertwisting sliding mode control | |
| CN109510248B (en) | Virtual synchronous inverter control method capable of inhibiting active oscillation and storage medium | |
| Xue et al. | Finite-control-set model predictive control for three-level NPC inverter-fed PMSM drives with $ LC $ filter | |
| Wallmark et al. | Input admittance expressions for field-oriented controlled salient PMSM drives | |
| CN112751346B (en) | Design method of DFIG-PSS controller based on virtual impedance | |
| WO2022134769A1 (en) | Control method for oscillation suppression of permanent magnet assisted synchronous reluctance motor | |
| Xia et al. | Feedback linearization control approach for brushless doubly-fed machine | |
| CN115102149A (en) | Overcurrent suppression system and method for network type converter | |
| CN113964858B (en) | Three-phase inverter grid-connected control system based on dual synchronization principle | |
| Liu et al. | Full speed range position-sensorless compound control scheme for PMSMs | |
| Jabbarnejad et al. | Power quality improvement using virtual flux combined control of grid connected converters under balanced and unbalanced grid operation | |
| CN111509767B (en) | High voltage ride through control method for wind power double-fed converter | |
| Chen et al. | Enhanced Q-axis Voltage Integral Damping Control for Fast PLL-Synchronized Inverters in Weak Grids | |
| Huang et al. | Comparison of DC-link voltage control schemes on grid-side and machine-side for type-4 wind generation system under weak grid | |
| Tao et al. | A phase compensation method combined with power correction for suppressing sub-synchronous resonance of wind generation under weak grid | |
| CN110224651B (en) | Open-phase control method for inhibiting second harmonic torque | |
| Li et al. | Sensorless Control of Dual Three-Phase IPMSM Based on Frequency Adaptive Linear Extended State Observer | |
| CN116865361A (en) | Virtual synchronous generator power control method based on fractional differentiation | |
| Sun et al. | A DC-link oscillation suppression strategy in metro traction drive system based on virtural damping resitor | |
| CN113839595B (en) | Harmonic wave and unbalanced current suppression method for double three-phase permanent magnet synchronous motor | |
| Chen et al. | Dynamics enhancement for power synchronization control with asymmetric ac voltage controller in strong grids | |
| CN114123245A (en) | Inverter controller, inverter grid-connected structure and power grid low-frequency oscillation suppression method | |
| Liang et al. | A position sensorless drive method with low computational cost and inductance identification for surface-mounted PMSM with hybrid converter | |
| Xu et al. | An advanced harmonic compensation strategy for dual three-phase permanent magnet synchronous machines considering different angle displacements | |
| Ding et al. | Harmonic suppression based on rectified current regulation with dc-link voltage decoupling for electrolytic capacitorless PMSM drives |
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 |