CN111965972A - Energy storage backstepping control method based on disturbance observer - Google Patents

Energy storage backstepping control method based on disturbance observer Download PDF

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CN111965972A
CN111965972A CN202010540450.5A CN202010540450A CN111965972A CN 111965972 A CN111965972 A CN 111965972A CN 202010540450 A CN202010540450 A CN 202010540450A CN 111965972 A CN111965972 A CN 111965972A
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converter
energy storage
controller
backstepping
current
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CN111965972B (en
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葛乐
吴雅楠
雷震
杨志超
徐文剑
张涛
郝雨辰
张友旺
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Nanjing Institute of Technology
State Grid Jiangsu Electric Power Co Ltd
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State Grid Jiangsu Electric Power Co Ltd
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    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B13/00—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion
    • G05B13/02—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric
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    • G05B13/042—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators in which a parameter or coefficient is automatically adjusted to optimise the performance
    • G05B13/045—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators in which a parameter or coefficient is automatically adjusted to optimise the performance using a perturbation signal
    • 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
    • H02J3/28—Arrangements for balancing of the load in a network by storage of energy
    • H02J3/32—Arrangements for balancing of the load in a network by storage of energy using batteries with converting means

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Abstract

The invention discloses an energy storage backstepping control method based on an interference observer, which comprises the steps of firstly, establishing a topological structure and a mathematical model of a two-stage energy storage converter, and analyzing reasons for causing direct-current voltage fluctuation; secondly, designing a backstepping method controller of the DC/AC converter in the two-stage energy storage converter by using a backstepping method based on the disturbance observer; and thirdly, designing a backstepping method controller of the DC/DC bidirectional converter in the two-stage energy storage converter by using a backstepping method based on the disturbance observer. A controller of the energy storage converter is designed by adopting a backstepping method based on a disturbance observer. Finally, Matlab/Simulink simulation verifies that the control algorithm has better robustness and dynamic response performance compared with a backstepping control algorithm. The robustness and the dynamic response capability of the backstepping control are improved, and the real-time tracking compensation of the direct-current voltage fluctuation can be effectively realized under the condition of not increasing a voltage/current sensor.

Description

Energy storage backstepping control method based on disturbance observer
Technical Field
The invention relates to the technical field of energy storage converters, in particular to an energy storage backstepping control method based on a disturbance observer.
Background
The stored energy plays more and more important roles in each link of power generation, transmission, distribution and use of a power grid due to the characteristics of electric energy storage, quick power response, flexible configuration and the like. The energy storage converter is an important component in an energy storage system, is accurately and quickly controlled, can ensure positive response to the power grid requirement, and enhances the flexibility of the power grid. Therefore, researches on the control technology of the energy storage converter are receiving more and more attention from students.
The energy storage bidirectional converter has two topological structures of a single-stage topology and a two-stage topology, and the single-stage topology is widely adopted at present because the single-stage topology has a small voltage working range and is not strong in applicability. The two-stage structure consists of a DC/DC bidirectional converter and a DC/AC converter. Under the energy storage grid-connected operation mode, the DC/AC responds to a power instruction of a power grid, accurate and quick power response is achieved, and meanwhile, the DC/DC bidirectional converter is used for stabilizing the voltage of a direct current side.
At present, the research on the control of the energy storage bidirectional converter mostly focuses on the aspect of linear control. The duty cycle of the DC/DC bi-directional converter and the output voltage of the DC/AC converter are both linearly modulated in accordance with a reduction in the error between the reference value and the sampled value. When external disturbance exists, the input error signal cannot change instantaneously, so that the output signal has typical transient impact and can reach new balance after a plurality of switching cycles. The backstepping method controller design is based on a nonlinear model, a high-order system is divided into a limited number of subsystems, so that the complexity of control law calculation is greatly reduced, and the high-order system has global stability through the stabilization design of each subsystem, which is a characteristic that a traditional linear control means does not have.
However, the controller of the back-stepping method puts higher requirements on the accuracy of the nonlinear model of the system, and when the system is sensitive or the voltage fluctuation of the direct-current side is large due to the change of the transmission power of the system, the back-stepping method cannot stabilize the power fluctuation by means of the robustness of the back-stepping method. Therefore, the power fluctuation of a system is equivalent to disturbance current in the design process of a back-step controller of the DC/DC bidirectional converter, a back-step method (DOPBS) control algorithm based on a disturbance observer is provided, the robustness and the dynamic response capability of the back-step method control are improved, and the real-time tracking compensation of the direct-current voltage fluctuation can be effectively realized without adding a voltage/current sensor.
Disclosure of Invention
The invention aims to: the energy storage backstepping control method based on the disturbance observer is provided to improve the robustness and the dynamic response capability of backstepping control, and can effectively realize real-time tracking compensation of direct-current voltage fluctuation under the condition of not increasing a voltage/current sensor.
The solution of the invention is: a disturbance observer-based energy storage backstepping (DOPBS) control method comprises the following steps:
the method comprises the following steps: establishing a topological structure and a mathematical model of the two-stage energy storage converter, and analyzing the reason of direct-current voltage fluctuation;
step two: a step-back method controller of a DC/AC converter in the two-stage energy storage converter is designed by a step-back method based on a disturbance observer;
step three: a backstepping method controller of a DC/DC bidirectional converter in a two-stage energy storage converter is designed by a backstepping method based on a disturbance observer.
In the first step, a topological structure of a two-stage energy storage converter is provided, the two-stage energy storage converter is formed by a DC/AC converter and a DC/DC bidirectional converter sharing a DC side, and a mathematical model of the two-stage energy storage converter comprises the following contents:
(1) the mathematical model of the DC/AC converter is as follows:
Figure BDA0002537414310000021
where ω is the grid angular frequency, id、iqD and q axis components, u, of the grid-connected current isd、usqD-and q-axis components, u, of the AC mains voltagerd、urqD-axis components and q-axis components of the AC side outlet voltage of the DC/AC converter respectively;
(2) the mathematical model of the DC/DC bidirectional converter is as follows:
in a Boost working state, a mathematical model is as follows:
Figure BDA0002537414310000022
in the formula, D2Is a switch tube S2Conducting time;
in the Buck working state, the mathematical model is as follows:
Figure BDA0002537414310000023
in the formula ibatFor outputting current, i, to a DC/DC bidirectional converteroFor system power fluctuation to be equivalent to the disturbance current amount on a direct current capacitor, D1Is a switch tube S1Conducting time;
neglecting the loss of the DC/DC bidirectional converter, under the steady state condition, the power of the energy storage end is balanced with the power of the DC side, and the power is expressed as:
uessiL＝udcibat (4)
wherein U isessFor the terminal voltage of the energy storage cell, iLOutput inductive current for energy storage, UdcIs a direct voltage ibatIs DC/DCThe bidirectional converter outputs a current.
(3) Cause of DC voltage fluctuation
Figure BDA0002537414310000031
UessFor the terminal voltage of the energy storage cell, iLOutput inductive current for energy storage, UdcThe DC/AC converter is a DC voltage, and P is active power output by the DC/AC converter;
in the second step, a backstepping method controller for designing the DC/AC converter in the two-stage energy storage converter by using a backstepping method based on the disturbance observer comprises the following contents:
step S1: let x1＝idControl amount urdIs marked as u1Control amount urqIs marked as u2The control quantity is abstracted as;
Figure BDA0002537414310000032
step S2: definition error eP1＝id-id_refThen, then
Figure BDA0002537414310000033
Step S3: defining a virtual control quantity:
Figure BDA0002537414310000034
in the formula, pi＞0；
Defining a virtual control quantity error: e.g. of the typeP2＝x2-αP1
Step S4: defining the Lyapunov function: vP2＝VP1+eP2 2/2
To make it possible to
Figure BDA0002537414310000035
The input control is designed as:
Figure BDA0002537414310000036
step S5: in the same way, let y1＝iq，eQ1＝iq-iq_refAt this time, the process of the present invention,
Figure BDA0002537414310000037
designing a virtual control quantity:
Figure BDA0002537414310000038
Figure BDA0002537414310000041
in the formula, q1＞0、q2＞0；
Step S6: united type (6) - (7):
Figure BDA0002537414310000042
step S7: solve to calculate the final control quantity urdAnd urq。
Step three, designing a backstepping method controller of a DC/DC converter in the two-stage energy storage converter by using a backstepping method based on the disturbance observer, wherein the controller comprises the following contents:
step A: remember udcIs x1，iLIs x2Amount of disturbance ioIs d1The disturbance current i in the Boost working stateoThe mathematical model of the DC/DC bidirectional converter is as follows:
Figure BDA0002537414310000043
and B: the general nonlinear system with interference is represented by the following matrix:
Figure BDA0002537414310000044
wherein, X1Is the system state, u1For control input, diFor disturbance, F1(x)，G1(x)，H1(x)，s1(x) Is a known smoothable function; l is the derivative of lie, m01Is m1(x) A minimum value; interference d1(t) satisfies the derivative bounded condition, namely:
Figure BDA0002537414310000045
and C: the DOPBS controller in the Boost working state is designed as follows:
Figure BDA0002537414310000046
Figure BDA0002537414310000047
z1＝x1
z2＝x2-α1
wherein k is1，1，β21，η21Are all adjustable parameters of the controller, and the controller is connected with the controller,
Figure BDA0002537414310000051
is a disturbance state d1Estimated value of, alpha1Is a virtual controller;
step D: similarly, the disturbance current i is obtained under the Buck working stateoThe mathematical model of the DC/DC converter is as follows:
Figure BDA0002537414310000052
step E: the general nonlinear system with interference is represented by the following matrix:
Figure BDA0002537414310000053
step F: the Buck operating state DOPBS controller is designed as follows:
Figure BDA0002537414310000054
Figure BDA0002537414310000055
z1′＝x1′
z2′＝x2′-α1′。
drawings
Fig. 1 shows a two-stage energy storage converter topology.
Fig. 2 is a DC/AC converter topology.
Fig. 3 is a DC/DC bi-directional converter topology.
Fig. 4 is a step-back method for controlling the active power waveform.
Fig. 5 is a DOPBS controlled active power waveform.
FIG. 6 shows the waveform of the inductor current controlled by the step-back method and DOPBS.
FIG. 7 shows the waveforms of the step-back method and DOPBS control DC voltage.
Detailed Description
In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific embodiments.
The invention provides a disturbance observer-based energy storage back-stepping (DOPBS) control method, which comprises the following steps:
according to the mathematical model of the DC/AC converter shown in the figure 2, the current reference instruction signal i of the current loop reverse control loop is obtained according to the active and reactive reference instructions of the power gridd_refAnd iq_refAfter passing through the back-steering controller, the control instruction u is outputrdAnd urq. Designing a back-stepping controller for tracking the power instruction of the power grid by the DC/AC converter, wherein the process is as follows:
step 1: let x1＝idControl amount urdIs marked as u1Control amount urqIs marked as u2At this time, the control amount may be abstracted as:
Figure BDA0002537414310000061
substituting formula (2) for formula (15) to obtain:
Figure BDA0002537414310000062
recording:
Figure BDA0002537414310000063
equation (15) is further abstracted as:
Figure BDA0002537414310000064
step 2: definition error eP1＝id-id_refThen, then
Figure BDA0002537414310000065
And step 3: defining a virtual control quantity:
Figure BDA0002537414310000066
in the formula, p1＞0。
Defining a virtual control quantity error:
eP2＝x2-αP1 (17)
the Lyapunov function is also defined: vP1＝eP1 2A/2, then
Figure BDA0002537414310000071
Substituting formula (17) for formula (18) to obtain:
Figure BDA0002537414310000072
at this time, if eP2When the value is equal to 0, then
Figure BDA0002537414310000073
Further design is therefore required.
And 4, step 4: defining the Lyapunov function:
VP2＝VP1+eP2 2/2
due to the fact that
Figure BDA0002537414310000074
Then there are:
Figure BDA0002537414310000075
to make it possible to
Figure BDA0002537414310000076
The input control is designed as:
Figure BDA0002537414310000077
in the formula p2Is a normal number.
In the same way, let y1＝iq，eQ1＝iq-iq_refAt this time, the process of the present invention,
Figure BDA0002537414310000078
designing a virtual control quantity:
Figure BDA0002537414310000079
Figure BDA00025374143100000710
in the formula, q1＞0、q2＞0。
Finally calculate urd、urqAnd the vertical type (21) and (22) are connected:
Figure BDA0002537414310000081
recording:
Figure BDA0002537414310000082
Figure BDA0002537414310000083
Figure BDA0002537414310000084
Figure BDA0002537414310000085
solved according to Cramer's law:
Figure BDA0002537414310000086
Figure BDA0002537414310000087
the final controlled variable u can be calculated from the equation (23)rdAnd urq。
Therefore, the system is finally decomposed into simpler subsystems, and the whole system is gradually stabilized in the global sense through the control law design of the two subsystems.
The DOPBS consideration herein is a generally second order nonlinear system with interference as follows:
Figure BDA0002537414310000088
y＝s(x)
in the formula xiIs the system state, y is the system output state signal, hi、giS (1. ltoreq. i. ltoreq.2) is a known smooth differentiable function, di(t) is an unknown bounded interference, hence di(t) satisfies the following condition:
Figure BDA0002537414310000089
the DOPBS controller is designed based on the traditional backstepping method, and then a nonlinear disturbance observer is designed in a targeted manner. The bounded disturbance of the system is taken into account in the control law derivation process, and finally the closed-loop system can be stabilized under the condition of the bounded disturbance. The nonlinear disturbance observer model designed herein is as follows:
Figure RE-GDA0002703892410000091
in the formula
Figure BDA0002537414310000093
To disturb di(t) estimated value, qiBeing the state of a non-linear disturbance observer, pi(xi) Is a nonlinear function to be designed,/i(xi) Is a non-linear observation gain function and satisfies the followingExpression:
Figure BDA0002537414310000094
defining an interference estimation error:
Figure BDA0002537414310000095
the interference estimation error can be described by the following system:
Figure BDA0002537414310000096
the DOPBS herein is represented after considering the following general nonlinear system matrixing with interference:
Figure BDA0002537414310000097
in the formula
Figure BDA0002537414310000098
G(x)＝[G1(x)，G2(x)，...，Gn(x)]，
Wherein the content of the first and second substances,
Figure BDA0002537414310000099
i＝1，2，...，n-1，
Figure BDA00025374143100000910
U(t)＝[1，...，1，u]T，H(x)＝[H1(x)，H2(x)，...，Hn(x)]，
Figure BDA00025374143100000911
D(t)＝[d1，d2，...，dn]T
to better estimate the interference, the relative order of the interference to the output needs to be taken into account. For this reason, the following assumptions are given:
suppose system (4-20) interference diRelative order to output s (x) is riSo that
Figure BDA00025374143100000912
1, 2.. n, where L denotes the lie derivative, mi(x) Is bounded within the feasible domain, and mi(x) Can be further decomposed into:
mi(x)＝m0i+mii(x) (30)
in the formula m0iIs mi(x) Minimum value of (1), mii(x) If > 0, then pi(xi) The following were chosen:
Figure BDA00025374143100000913
at this time, the interfering system (4-19) can be further described as:
Figure BDA0002537414310000101
the power fluctuation of the AC side and the DC side is equivalent to disturbance current on a DC capacitor, and the disturbance current i is considered in the design process of a backstepping method controller of a DC/DC bidirectional converteroAnd the DOPBS controller is designed to inhibit fluctuation, so that the closed-loop system meets asymptotic stability in the working state of the DC/DC bidirectional converter Boost/Buck. The energy storage DC/DC bidirectional converter is controlled to balance the unbalanced power of the system by modulating the conduction time of the energy storage DC/DC bidirectional converter in a Boost/Buck working state, and the influence on the direct-current voltage is weakened.
The details of designing the inverter controller based on the disturbance observer according to the mathematical model of the DC/DC bidirectional converter obtained in fig. 3 are as follows.
(a) Boost operating state
Remember udcIs x1，iLIs x2Amount of disturbance ioIs d1And then the belt disturbance is generated in the Boost working stateCurrent ioThe mathematical model of the DC/DC bidirectional converter is as follows:
Figure BDA0002537414310000102
matrixing equation (4-11), written as follows:
Figure BDA0002537414310000103
note X1＝[x1，x2]T，
Figure BDA0002537414310000104
G1(x)＝[g1(x)，g2(x)]T，g1(x)＝[0，0]T，
Figure BDA0002537414310000105
u1＝[1，D2]T，H1(x)＝[h1(x)，h2(x)]T，
Figure BDA0002537414310000106
h2(x)＝[0，0]TD disturbance d1(t)＝[d1(t)，0]T，s1(x)＝[x1，x2]T，
Figure BDA0002537414310000107
m2(x) 0, can choose
Figure BDA0002537414310000108
Wherein, X1Is the system state, u1For control input, diFor disturbance, F1(x)，G1(x)，H1(x)，s1(x) Is a known smoothable function. L is the derivative of lie, m01Is m1(x) A minimum value. Interference d1(t)The derivative bounded condition is satisfied, namely:
Figure BDA0002537414310000109
the DOPBS controller in the Boost working state is designed as follows:
Figure BDA0002537414310000111
wherein the content of the first and second substances,
Figure BDA0002537414310000112
z1＝x1
z2＝x2-α1
wherein k is1，1，β21，η21Are all adjustable parameters of the controller, and the controller is connected with the controller,
Figure BDA0002537414310000113
is a disturbance state d1Estimated value of, alpha1Is a virtual controller.
(b) Buck operating state
With disturbance current i in Buck operating stateoThe mathematical model of the DC/DC bidirectional converter is as follows:
Figure BDA0002537414310000114
in the same way, the method for preparing the composite material,
Figure BDA0002537414310000115
note X2＝[x1′，x2′]T，
Figure BDA0002537414310000116
C2(x)＝[g1′(x)，g2′(x)]T，g1′(x)＝[0，0]T，
Figure BDA0002537414310000117
u2＝[1，D2]T，H2(x)＝[h1′(x)，h2′(x)]T，
Figure BDA0002537414310000118
h2′(x)＝[0，0]TD disturbance d1′(t)＝[d1′(t)，0]T，
Figure BDA0002537414310000119
m2' (x) ═ 0, m can be selected01′＝0，
Figure BDA00025374143100001110
The Buck operating state DOPBS controller is designed as follows:
Figure BDA0002537414310000121
wherein the content of the first and second substances,
Figure BDA0002537414310000122
z1′＝x1′
z2′＝x2′-α1′
a two-stage energy storage converter model shown in figure 1 is established for simulation based on Matlab/Simulink, and the back-stepping control effect and the DOPBS control effect are compared, so that the feasibility of the DOPBS control algorithm is verified.
The simulation parameter settings are shown in table 1:
TABLE 1 simulation parameters
Figure BDA0002537414310000123
Fig. 4 to 7 are graphs showing the control effect comparison of back-stepping and DOPBS, fig. 4 and 5 are graphs showing the tracking curves of the active power and the energy storage active power of the power grid when the back-stepping and DOPBS controllers regulate, fig. 6 is a graph showing the control effect comparison of back-stepping and DOPBS on the dc voltage, and fig. 7 is a graph showing the control effect comparison of back-stepping and DOPBS on the inductive current. Due to actual loss, the converter cannot completely send out corresponding active power according to a power instruction value required by a power grid, actually sent power fluctuates around the instruction value, and energy storage charge and discharge power is controlled to balance unbalanced power of the system.
The active power required by the power grid is suddenly increased from 0.1MW to 0.5MkW at the moment of 0.2s, the output power is correspondingly increased by the stored energy, the output inductive current is increased, and the direct-current voltage drop is caused. At the moment of 0.4s, the power is suddenly reduced from 0.5MW to-0.2 MW, the stored energy reduces the output force, the output inductive current is reduced, and the direct-current voltage is increased. Under two working conditions, a back-stepping controller and a DOPBS controller are respectively adopted to regulate the stored functional output, the output inductive current and the direct current voltage. By contrast, the active power tracking oscillation is obviously higher than that of the DOPBS controller during back-stepping control. The final simulation result shows that the DOPBS controller can quickly respond when the system power oscillates, and effectively restrain the power oscillation in a shorter time so as to enable the power oscillation to be stabilized at a desired value. Due to sudden increase and sudden decrease of power, the stored energy output inductive current also changes correspondingly, when back-tapping control is adopted, oscillation is obvious, the maximum amplitude reaches about 1kA, the inductive current recovery time is also longer, the dynamic characteristic regulated by using the DOPBS controller has obvious advantages, and the characteristics are specifically embodied in that the current fluctuation range is small, and the regulation time is short.
When a back-stepping controller is adopted, the direct current voltage UdcThe oscillation amplitude is large, the maximum amplitude is close to 50V, and the adjusting time is long. The adoption of the DOPBS controller has obvious voltage regulation effect and direct current voltage UdcThe oscillation amplitude is obviously reduced, the power suddenly increases at the instant, the direct current voltage UdcOnly falls by about 20V and is extremelyThe temperature is recovered to 650V in a short time; at 0.4s, the power suddenly drops, and the stored energy is continuously charged to cause the DC voltage to rise. When the voltage is regulated by a back-stepping controller, the voltage is stabilized at 650V after oscillation, the maximum voltage climbing amplitude is close to 60V, and when the voltage is regulated by a DOPBS controller, the voltage UdcThe amplitude is only 25V at the maximum, and the adjusting time is also greatly shortened.

Claims (4)

1. An energy storage backstepping control method based on a disturbance observer is characterized by specifically comprising the following steps:
the method comprises the following steps: establishing a topological structure and a mathematical model of the two-stage energy storage converter, and analyzing the reason of direct-current voltage fluctuation;
step two: a step-back method controller of a DC/AC converter in the two-stage energy storage converter is designed by a step-back method based on a disturbance observer;
step three: a backstepping method controller of a DC/DC bidirectional converter in a two-stage energy storage converter is designed by a backstepping method based on a disturbance observer.
2. The disturbance observer-based energy storage backstepping control method according to claim 1, wherein: in the first step, a topological structure and a mathematical model of the two-stage energy storage converter are established, and the reason causing direct-current voltage fluctuation is analyzed, wherein the two-stage energy storage converter is formed by a DC/AC converter and a DC/DC bidirectional converter sharing a direct-current side, and the mathematical models are respectively as follows:
(1) the mathematical model of the DC/AC converter is as follows:
Figure FDA0002537414300000011
where ω is the grid angular frequency, id、iqD and q axis components, u, of the grid-connected current isd、usqD-and q-axis components, u, of the AC mains voltagerd、urqD-axis components and q-axis components of the AC side outlet voltage of the DC/AC converter respectively;
(2) the mathematical model of the DC/DC bidirectional converter is as follows:
in a Boost working state, a mathematical model is as follows:
Figure FDA0002537414300000012
in the formula, D2Is a switch tube S2Conducting time;
in the Buck working state, the mathematical model is as follows:
Figure FDA0002537414300000013
in the formula ibatFor outputting current, i, to a DC/DC bidirectional converteroFor system power fluctuation to be equivalent to the disturbance current amount on a direct current capacitor, D1Is a switch tube S1Conducting time;
neglecting the loss of the DC/DC bidirectional converter, under the steady state condition, the power of the energy storage end is balanced with the power of the DC side, and the power is expressed as:
uessiL＝udcibat (4)
wherein U isessFor the terminal voltage of the energy storage cell, iLOutput inductive current for energy storage, UdcIs a direct voltage ibatAnd outputting current for the DC/DC bidirectional converter.
(3) Cause of DC voltage fluctuation
Figure FDA0002537414300000021
UessFor the terminal voltage of the energy storage cell, iLOutput inductive current for energy storage, UdcIs direct current voltage, and P is the active power output by the DC/AC converter.
3. The disturbance observer-based energy storage backstepping control method according to claim 1, wherein: in the second step, a backstepping method controller for designing the DC/AC converter in the two-stage energy storage converter by using a backstepping method based on the disturbance observer comprises the following contents:
designing a backstepping method controller for tracking the power instruction of the power grid by the DC/AC converter, and comprising the following steps of:
step S1: let x1＝idControl amount urdIs marked as u1Control amount urqIs marked as u2The control quantity is abstracted as;
Figure FDA0002537414300000022
step S2: definition error eP1＝id-id_refThen, then
Figure FDA0002537414300000023
Step S3: defining a virtual control quantity:
Figure FDA0002537414300000024
in the formula, p1＞0；
Defining a virtual control quantity error: e.g. of the typeP2＝x2—αP1
Step S4: defining the Lyapunov function: vP2＝VP1+eP2 2/2
To make it possible to
Figure FDA0002537414300000025
The input control is designed as:
Figure FDA0002537414300000026
step S5: in the same way, let y1＝iq，eQ1＝iq-iq_refAt this time, the process of the present invention,
Figure FDA0002537414300000027
designing a virtual control quantity:
Figure FDA0002537414300000028
Figure FDA0002537414300000031
in the formula, q1＞0、q2＞0；
Step S6: united type (6) - (7):
Figure FDA0002537414300000032
step S7: solve to calculate the final control quantity urdAnd urq。
4. The disturbance observer-based energy storage backstepping control method according to claim 1, wherein: in the third step, a step-back method controller for designing the DC/DC converter in the two-stage energy storage converter by using a step-back method based on the disturbance observer comprises the following contents:
step A: remember udcIs x1，iLIs x2Amount of disturbance ioIs d1The disturbance current i in the Boost working stateoThe mathematical model of the DC/DC bidirectional converter is as follows:
Figure FDA0002537414300000033
and B: the general nonlinear system with interference is represented by the following matrix:
Figure FDA0002537414300000034
wherein, X1Is the system state, u1For control input, diFor disturbance, F1(x)，G1(x)，H1(x)，s1(x) Is a known smoothable function; l is the derivative of lie, m01Is m1(x) A minimum value; interference d1(t) satisfies the derivative bounded condition, namely:
Figure FDA0002537414300000035
and C: the DOPBS controller in the Boost working state is designed as follows:
Figure FDA0002537414300000036
wherein k is1，1，β21，η21Are all adjustable parameters of the controller, and the controller is connected with the controller,
Figure FDA0002537414300000041
is a disturbance state d1Estimated value of, alpha1Is a virtual controller;
step D: similarly, the disturbance current i is obtained under the Buck working stateoThe mathematical model of the DC/DC converter is as follows:
Figure FDA0002537414300000042
step E: the general nonlinear system with interference is represented by the following matrix:
Figure FDA0002537414300000043
step F: the Buck operating state DOPBS controller is designed as follows:
Figure FDA0002537414300000044
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