CN113937818A - Bus voltage stabilization control method for photovoltaic power generation system - Google Patents
Bus voltage stabilization control method for photovoltaic power generation system Download PDFInfo
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- CN113937818A CN113937818A CN202111332593.8A CN202111332593A CN113937818A CN 113937818 A CN113937818 A CN 113937818A CN 202111332593 A CN202111332593 A CN 202111332593A CN 113937818 A CN113937818 A CN 113937818A
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- 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
- H02J3/381—Dispersed generators
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
- H02M7/5387—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
- H02M7/53871—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current
- H02M7/53875—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current with analogue control of three-phase output
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
- H02M7/539—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters with automatic control of output wave form or frequency
- H02M7/5395—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters with automatic control of output wave form or frequency by pulse-width modulation
-
- 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
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
- H02J2300/22—The renewable source being solar energy
- H02J2300/24—The renewable source being solar energy of photovoltaic origin
-
- 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
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
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- Engineering & Computer Science (AREA)
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Abstract
The invention relates to a bus voltage stabilization control method of a photovoltaic power generation system, which comprises the following steps: 1) the values of alternating voltage, alternating current, direct current bus voltage and phase angle obtained according to the voltage and current sampling and the phase-locked loop are sent to a DSP chip (TS 28379D); 2) converting the alternating voltage and the current quantity obtained by the sampling circuit into quantities corresponding to d-q axes through coordinate transformation; 3) obtaining trigger pulses of the three-phase fully-controlled bridge by a two-level space vector pulse width modulation control method; and further realizing the flow of energy from the direct current bus to the power grid.
Description
Technical Field
The invention relates to a control method for optimizing grid voltage orientation vector control by an active disturbance rejection technology, which is mainly applied to the field of photovoltaic power generation and can solve the problems of illumination change, system complexity, grid voltage fluctuation, load change and the like.
Background
In recent years, the problems of energy crisis and environmental pollution are increasingly highlighted. Therefore, research, development and utilization of new energy are inevitable processes for solving energy exhaustion and environmental pollution. Solar energy is one of renewable natural energy, is distributed all over the world, is environment-friendly, reliable and convenient to use, and is one of the green energy sources which are used as the most extensive and development potential of energy structure adjustment at present. However, due to the randomness of illumination and the strong uncertainties of nonlinearity, variable parameters and the like of the photovoltaic power generation system, the voltage stability at the bus of the photovoltaic power generation system is greatly challenged, and the large-scale application of photovoltaic power generation is directly influenced. Therefore, optimizing the performance of the grid-side converter and its control strategy has a great practical significance for optimizing the economy, stability and safety of the photovoltaic power generation system.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: by taking a three-phase full-bridge inverter as an example, the problem that the direct-current bus voltage is influenced by disturbance and fluctuates greatly is solved by providing a power grid voltage directional vector control method applying an active disturbance rejection technology.
The invention is realized by adopting the following technical means: a bus voltage stabilization control method of a photovoltaic power generation system comprises the following steps:
1) the values of alternating voltage, alternating current, direct current bus voltage and phase angle obtained according to the voltage and current sampling and the phase-locked loop are sent to a DSP chip (TS 28379D);
2) converting the alternating voltage and the current quantity obtained by the sampling circuit into quantities corresponding to d-q axes through coordinate transformation;
3) obtaining trigger pulses of the three-phase fully-controlled bridge by a two-level space vector pulse width modulation control method; and further realizing the flow of energy from the direct current bus to the power grid.
The coordinate transformation is realized by the following formula:
the phase angle theta is the included angle between the d axis in the two-phase rotating d-q coordinate system and the a axis in the three-phase static coordinate system, and omega is the synchronous rotation angular velocity and is obtained by a phase-locked loop.
The two-level space vector pulse width modulation control method in the step 3 specifically comprises the following steps:
1) the voltage value u at the DC bus is measureddc*Setting the voltage value u at the DC bus as a predetermined value rdcInputting the feedback quantity y into an extended state observer of the active disturbance rejection controller for calculation; then through the linear state error feedback control law u0＝KP(r-z1)-z2Combining, and finally outputting a control signal of an outer ring;
2) taking the output signal of the outer loop as the input signal I of the inner loop controlgd*Then with IgdThe difference is output through a proportional-integral (PI) controller and is used as the final output of a d axis;
3) input signal taking low level as q axis and IgqThe difference is output through a PI controller and is used as the final output of a q axis, and then Clack inverse transformation is carried out to obtain the trigger pulse of the inverter; and further realizing the flow of energy from the direct current bus to the power grid.
A photovoltaic power generation system using a bus voltage stabilization method is provided, wherein an active disturbance rejection controller is arranged on an outer ring of the photovoltaic power generation system, and comprises a tracking differentiator, an extended state observer and a nonlinear state error feedback control law; the tracking differentiator is used for arranging a transition process and giving a reasonable control signal, so that the contradiction between response speed and overshoot is solved; the extended state observer is used for solving the influence of the unknown part of the model and the unknown disturbance outside on the control object, and then a signal is given to compensate the disturbance. Changing the control object into a common integral series control object; and the nonlinear error feedback control law gives a control strategy of the controlled object.
Compared with the prior art, the photovoltaic power generation system can effectively improve the transient response of the direct current bus voltage and aim at the directional vector control of the power grid voltage. The first-order active disturbance rejection control technology is embedded into an outer ring controller, control optimization is achieved, and the minimum fluctuation amplitude and the minimum transient process are obtained when the photovoltaic power generation system is affected by disturbance.
Drawings
FIG. 1 is a block diagram of a photovoltaic power generation system of the present invention;
FIG. 2 is a block diagram of the vector control of grid voltage orientation for the embedded active disturbance rejection technique of the present invention;
fig. 3 is a schematic diagram of the active disturbance rejection controller of the present invention.
Detailed Description
The technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiment of the present invention:
the invention relates to a bus voltage stabilization control method of a photovoltaic power generation system, which comprises the following steps:
1) the values of alternating voltage, alternating current, direct current bus voltage and phase angle obtained according to the voltage and current sampling and the phase-locked loop are sent to a DSP chip (TS 28379D);
2) converting the alternating voltage and the current quantity obtained by the sampling circuit into quantities corresponding to d-q axes through coordinate transformation;
3) obtaining trigger pulses of the three-phase fully-controlled bridge by a two-level space vector pulse width modulation control method; and further realizing the flow of energy from the direct current bus to the power grid.
The coordinate transformation is realized by the following formula:
the phase angle theta is the included angle between the d axis in the two-phase rotating d-q coordinate system and the a axis in the three-phase static coordinate system, and omega is the synchronous rotation angular velocity and is obtained by a phase-locked loop.
The vector control block diagram of the invention is shown in figure 2, and the direct current busVoltage value u at linedc*Setting the voltage value u at the DC bus as a predetermined value rdcInputting the feedback quantity y into an extended state observer of the active disturbance rejection controller for calculation; then through the linear state error feedback control law u0＝KP(r-z1)-z2And combining and finally outputting the control signal of the outer ring. Taking the output signal of the outer loop as the input signal I of the inner loop controlgd*Then with IgdThe difference is output through a proportional-integral (PI) controller as the final output of the d-axis. Input signal taking low level as q axis and IgqAnd outputting the difference through a PI controller to be used as the final output of the q axis, and then performing reverse Clack transformation. Obtaining a trigger pulse of the inverter by a two-level space vector pulse width modulation control method; and further realizing the flow of energy from the direct current bus to the power grid.
The two-level space vector pulse width modulation control method mainly aims at an inverter circuit and generates eight basic voltage space vectors according to different switch combination modes; under a space rotating coordinate system, required voltage vectors are generated by optimizing and arranging the action time of the voltage vectors in adjacent sectors, and then trigger pulse waveforms are obtained. The three-phase voltage synthesized space vector u (t) can be expressed as:
it can be seen that u (t) is a rotating space vector with amplitude equal to the peak value of the phase voltage, and rotates at a constant speed in the counterclockwise direction at an angular frequency ω ═ 2 π f, and the SVPWM (sine wave pulse width modulation) algorithm represents the rotating vector u (t) in space by using the switching state of the three-phase bridge.
The vector control calculation is that in the coordinate transformation process, a vector E synthesized by the grid voltage is oriented on a d axis in a d-q coordinate system, and a phase voltage peak point of a phase angle theta is taken as a zero point of the phase angle theta, so that U existsgd＝|E|、Ugq0; further according to the instantaneous power theory, the output instantaneous active power P can be obtainedgAnd instantaneous reactive power QgSee equation 3:
wherein: u shapegd、Ugq、Igd、IgqThe d and q axis components of the grid side inverter voltage and current, respectively.
The reverse transformation of the Clack is carried out by adopting the following formula 4:
the grid voltage orientation vector control method of the active disturbance rejection controller structure is in an outer ring, namely udcThe access link introduces an active disturbance rejection control technology according to a disturbance observation channel z2And the control strategy based on disturbance elimination is realized by observing and compensating the total disturbance.
In addition, disturbance observation channel z is controlled based on active disturbance rejection2The estimation of the coupling item also avoids the design of cross decoupling, further simplifies the structure of the active disturbance rejection controller and the calculation process of a DSP (digital signal processor), and realizes the optimized control of the DC bus voltage.
The invention also relates to a photovoltaic power generation system using the bus voltage stabilizing method, an active disturbance rejection controller is arranged on an outer ring of the photovoltaic power generation system, the active disturbance rejection controller is shown in figure 3, wherein: r is a bus voltage reference input; y is the output; b1To control the gain; z is a radical of1An observed value of y; z is a radical of2Is composed of
The observed value of (a); z is a radical of3Is the observed value of the total disturbance; u is a control amount.
The n-order system is expressed as a differential equation:
wherein: u and y are input and output of the controlled object; w represents an unknown external disturbance; f is an equal uncertainty item of a total disturbance comprising a system model unknown part, an element parameter fluttering part, an external disturbance w and an estimation error part; b is the controller gain.
Order to
And x ═ x1x2 … x(n+1)]TAssuming that f is a derivative of the sum of the numbers,
wherein:
corresponding to a continuous Linear Extended State Observer (LESO) of
Wherein: z → x, z and
respectively, the state variable matrix and its derivative matrix. L is a gain matrix L ═ L of the state observer to be designed1 l2 … ln ln+1]T. Due to disturbance term
Unknown and can be estimated by the correction term, and thus omitted from equation (3.3)
The observer equation is rewritten and the observer equation is rewritten,
wherein: u. ofc＝[u y]TIs a combined input, ycIs the output.
Introducing observer bandwidth omega0Setting the L parameter; in the formula I1,l2,…,ln,ln+1For the parameters of the matrix L, a parameterization result can be obtained, so that the characteristic polynomial of the observer is as follows:
sn+1+l1sn+…+lns+ln+1＝(s+ω0)n+1 (5)
the observer's state variable z as the system becomes progressively stablei(i ═ 1,2,3, …, n +1) will track the state variable x of the system1Namely:
Claims (4)
1. a bus voltage stabilization control method of a photovoltaic power generation system is characterized by comprising the following steps: the method comprises the following steps:
1) the values of alternating voltage, alternating current, direct current bus voltage and phase angle obtained according to the voltage and current sampling and the phase-locked loop are sent to a DSP chip (TS 28379D);
2) converting the alternating voltage and the current quantity obtained by the sampling circuit into quantities corresponding to d-q axes through coordinate transformation;
3) obtaining trigger pulses of the three-phase fully-controlled bridge by a two-level space vector pulse width modulation control method; and further realizing the flow of energy from the direct current bus to the power grid.
2. The bus voltage stabilization control method of the photovoltaic power generation system according to claim 1, characterized in that: the coordinate transformation is realized by the following formula:
the phase angle theta is the included angle between the d axis in the two-phase rotating d-q coordinate system and the a axis in the three-phase static coordinate system, and omega is the synchronous rotation angular velocity and is obtained by a phase-locked loop.
3. The bus voltage stabilization control method of the photovoltaic power generation system according to claim 1, characterized in that: the two-level space vector pulse width modulation control method in the step 3 specifically comprises the following steps:
1) the voltage value of the DC bus
Setting the voltage value u at the DC bus as a predetermined value rdcInputting the feedback quantity y into an extended state observer of the active disturbance rejection controller for calculation; then through the linear state error feedback control law u0＝KP(r-z1)-z2Combining, and finally outputting a control signal of an outer ring;
2) using the output signal of the outer loop as the input signal of the inner loop control
Then with IgdThe difference is output through a proportional-integral (PI) controller and is used as the final output of a d axis;
3) input signal taking low level as q axis and IgqThe difference is output through a PI controller and is used as the final output of a q axis, and then Clack inverse transformation is carried out to obtain the trigger pulse of the inverter; and further realizing the flow of energy from the direct current bus to the power grid.
4. A photovoltaic power generation system using a bus voltage stabilization method is characterized in that: an active disturbance rejection controller is arranged on the outer ring of the photovoltaic power generation system, and comprises a tracking differentiator, an extended state observer and a nonlinear state error feedback control law; the tracking differentiator is used for arranging a transition process and giving a reasonable control signal, so that the contradiction between response speed and overshoot is solved; the extended state observer is used for solving the influence of the unknown part of the model and the unknown disturbance outside on the control object, and then a signal is given to compensate the disturbance. Changing the control object into a common integral series control object; and the nonlinear error feedback control law gives a control strategy of the controlled object.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20190288611A1 (en) * | 2018-03-13 | 2019-09-19 | Shanghai Jiao Tong University | Nonlinear control method for micro-grid inverter with anti-disturbance |
| CN110957756A (en) * | 2019-10-29 | 2020-04-03 | 国网江苏省电力有限公司盐城供电分公司 | Photovoltaic inverter voltage control circuit based on active disturbance rejection technology |
| CN111555318A (en) * | 2020-05-29 | 2020-08-18 | 天津理工大学 | Control method of super-capacitor energy storage grid-connected system based on improved LADRC |
| CN111884502A (en) * | 2020-07-09 | 2020-11-03 | 三峡大学 | DC-DC converter cascade linear active disturbance rejection voltage control method |
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- 2021-11-11 CN CN202111332593.8A patent/CN113937818A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20190288611A1 (en) * | 2018-03-13 | 2019-09-19 | Shanghai Jiao Tong University | Nonlinear control method for micro-grid inverter with anti-disturbance |
| CN110957756A (en) * | 2019-10-29 | 2020-04-03 | 国网江苏省电力有限公司盐城供电分公司 | Photovoltaic inverter voltage control circuit based on active disturbance rejection technology |
| CN111555318A (en) * | 2020-05-29 | 2020-08-18 | 天津理工大学 | Control method of super-capacitor energy storage grid-connected system based on improved LADRC |
| CN111884502A (en) * | 2020-07-09 | 2020-11-03 | 三峡大学 | DC-DC converter cascade linear active disturbance rejection voltage control method |
Non-Patent Citations (2)
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| 朱士加 等: "一阶LADRC 的风电并网控制及其稳定性分析", 《电力系统及其自动化学报》 * |
| 赵尔全 等: "自抗扰控制器的建模与仿真分析", 《青岛理工大学学报》 * |
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