Improved active-disturbance-rejection control method for optical storage converter based on fractional order complementary sliding mode

Abstract

The invention discloses an improved active-disturbance-rejection control method for an optical storage converter based on a fractional order complementary sliding mode, and aims to solve the problem that a conventional observer is not high in observation precision and observes the high-order derivative of external disturbance. According to sliding mode control, a system generates certain buffeting due to internal discontinuity when reaching a sliding mode surface, and in order to enable a control signal to be continuous and smooth to reduce buffeting, a double-power reaching law is introduced to improve the buffeting phenomenon of sliding mode control; a fractional order complementary sliding mode is designed to improve the tracking precision of the system aiming at the problem that the traditional sliding mode control is not high in tracking precision, so that the controller realizes faster and more accurate control.

Description

Technical Field

[0001] The present invention belongs to the technical field of power electronics, and particularly relates to an improved active disturbance rejection control method for a photovoltaic energy storage converter based on fractional-order complementary sliding mode. Background Technique

[0002] Solar energy is an ideal clean energy source. It is not only inexhaustible in quantity but also low in cost. An important device in photovoltaic power generation is the photovoltaic grid-connected inverter, which is a non-linear, strongly coupled, and multi-variable system. The main measure to ensure the stability of the photovoltaic system is to ensure the stability of the DC bus voltage. The DC bus voltage is affected by light, temperature, grid-side voltage, and load switching. To maintain its voltage stability, it is necessary to further study new control strategies for photovoltaic grid-connected inverters to ensure their stable operation under various conditions.

[0003] In a photovoltaic energy storage grid-connected system, the photovoltaic and energy storage batteries coupled through the DC bus are important components of the photovoltaic energy storage converter. Traditional PI control is difficult to control due to its non-linearity, strong coupling, and multi-input multi-output characteristics, making it difficult to meet the control requirements. In the face of control requirements such as high precision and fast response of the photovoltaic energy storage converter, researchers at home and abroad have proposed various control methods, such as sliding mode control, active disturbance rejection control, fuzzy control, and model predictive control. Although fuzzy control is simple to control and does not require the mathematical model of the controlled object, its lack of systematicness and difficulty in parameter adjustment have some impact on the stable control of the photovoltaic energy storage converter. Although model predictive control is good at dealing with multi-input multi-output systems, its complex calculation and influence by model errors and other factors make it unable to have sufficient control over the photovoltaic energy storage converter. Active disturbance rejection control is a new type of practical control technology. This control technology does not depend on the accuracy of the mathematical model of the controlled object and has strong anti-interference ability and robustness. Traditional ADRC adopts a non-linear form and requires a large number of parameters to be tuned, which is not conducive to engineering practice. Summary of the Invention

[0004] The purpose of the present invention is to provide an improved active disturbance rejection control method for a photovoltaic energy storage converter based on fractional-order complementary sliding mode to enhance the robustness and steady-state accuracy of the photovoltaic energy storage converter system.

[0005] The technical solution adopted by the present invention is an improved active disturbance rejection control method for a photovoltaic energy storage converter based on fractional-order complementary sliding mode, which is used to control the latter-stage converter of the photovoltaic energy storage converter. The latter-stage converter includes a three-phase full-bridge inverter, LC filtering, grid connection side, and load, and is specifically implemented according to the following steps: Step 1: Construct an equivalent mathematical model of the three-phase full-bridge inverter; Step 2: Construct a mathematical model in the d-q axis rotating coordinate system through dq transformation according to the equivalent mathematical model constructed in Step 1; Step 3: Construct the active disturbance rejection control paradigm and design a reduced-order generalized proportional-integral observer; Step 4: The given active power and reactive power pass through the power outer loop to obtain the current reference values of the d-q axes of the current inner loop; Step 5: Design a fractional-order complementary sliding mode surface and a double power reaching law to construct a sliding mode controller; Step 6: Obtain the control output through the sliding mode controller, use SPWM modulation to obtain the duty cycle, and apply the duty cycle to the control of the switching tubes of the three-phase full-bridge inverter, so as to realize the signal control of the full-bridge switch.

[0006] The characteristics of the present invention also lie in that, Step 1 is specifically as follows: The mathematical model of the three-phase full-bridge inverter in the photovoltaic energy storage converter in the three-phase coordinate system is: (1) In formula (1), U ao and U bo and U co are respectively the sum of the voltages of the filtering parts of the a, b, and c phases of the three-phase inverter and the grid-side voltage, R is the equivalent resistance, i a and i b and i c are respectively the output phase currents of the a, b, and c phases of the three-phase full-bridge inverter, L is the AC-side filtering inductor of the three-phase full-bridge inverter, e a and e b and e c are respectively the grid-side voltages of the a, b, and c phases.

[0007] Step 2 is specifically as follows, Convert formula (1) from the three-phase coordinate system to the two-phase rotating d-q coordinate system, and its mathematical model in the dq two-phase coordinate system is: (2) In formula (2), R is the filtering resistance of the three-phase full-bridge inverter, ω is the grid voltage angular frequency; u dr and u qr are respectively the output voltages on the d and q axes, udr = s d u dc 、 u qr = s q u dc ; s d 、s q are the d - axis and q - axis switching functions respectively; u dc is the DC - side bus voltage; e d 、 e q are the components of the grid voltage on the d - axis and q - axis; i Ld 、 i Lq are the components of the grid - side current on the d - axis and q - axis; Differentiate Equation (2) and transform it into a normal form that satisfies second - order active disturbance rejection: (3).

[0008] Step 3 is specifically as follows: Expand Equation (3) as follows: (4) In Equation (4), is the grid voltage angular frequency; Convert Equation (4) into the ADRC normal form to get: (5) In Equation (5), b d 、 b q are the control quantity gains on the d - axis and q - axis respectively, F d 、 F q are the equivalent lumped disturbances on the d - axis and q - axis respectively. The lumped disturbance includes the unmodeled part of the system, the coupling part, and the internal and external disturbances of the system. The expression of the lumped disturbance is: (6) Define the d - axis state variables 、 、 , and the q - axis state variables are 、 、 , then the state - space equation of the system shown in Equation (4) is: (7) Design the form of the reduced - order generalized proportional - integral observer RGPIO according to Equation (7) as: (8) In formula (8), β 1 , β 2 , β 3 >0, are all the observer gains of the d-axis; h 1 , h 2 , h 3 >0, are all the observer gains of the q-axis, z d1 , z d2 , z d3 , z q1 , z q2 , z q3 are respectively x d2 , x d3 , 、x q2 , x q3 , observation values of

[0009] .

[0010] Step 4 is specifically as follows, Set the reference values of the active power and reactive power of the photovoltaic energy storage converter as P ref , Q ref , when the photovoltaic energy storage converter is operating, the reference values of the inner-loop d-axis and q-axis currents i Ldref , i Lqref are respectively expressed as: (9).

[0011] Step 5 is specifically as follows, For the i Ld , i Lq after dq transformation and the deviation of their reference values e 1 , e 2 are constructed to obtain: (10) In Equation (10), i Ldref is i Ld 's reference value, i Lqref is i Lq 's reference value; The operator representing fractional calculus is defined as: (11) In Equation (11), is 's real part, is a real number and is the order of calculus; and t are respectively the upper and lower limits of the operator; According to the deviation value e 1 、 e 2 Design the fractional-order complementary sliding mode surfaces of the d-axis and q-axis s d 、 s q as: (12) In Equation (12), s dg 、 s qg are the generalized sliding mode surfaces of the dq-axis, s dc 、 s qc are the complementary sliding mode surfaces of the dq-axis; The generalized sliding mode surface of the dq-axis is defined as: (13) In Equation (13), s dg 、 s qg are the generalized sliding mode surfaces of the dq-axis, s dc 、 s qc are the complementary sliding mode surfaces of the dq-axis; The complementary sliding mode surface of the dq-axis is defined as: (14) Take the α -order time derivatives of both sides of Equation (13) and Equation (14) respectively to obtain: (15) It can be obtained from Equation (14) and Equation (15) that: (16) At this time, the Lyapunov function is defined as: (17) Take the α derivative of Equation (17), and according to Equations (13) to (17), we get: (18) Therefore, the complementary fractional-order sliding mode controller is designed as: (19) From Equation (18), we get u deq and u qeq as: (19) Introduce the double power reaching law: (20) Combining Equation (20) and Equation (21), we get the complete control law u dr , u qr as: (22).

[0012] In Equation (21), , .

[0013] The beneficial effects of the present invention are: The improved active disturbance rejection control method of the photovoltaic energy storage converter based on fractional-order complementary sliding mode in the present invention observes the high-order derivative of external disturbances in view of the low observation accuracy of the traditional observer; due to the internal discontinuity, the sliding mode control usually causes a certain chattering when reaching the sliding mode surface. In order to make the control signal continuous and smooth to reduce the generation of chattering, the double power reaching law is introduced to improve the chattering phenomenon of the sliding mode control. A fractional-order complementary sliding mode is designed to improve the tracking accuracy of the system in view of the low tracking accuracy of the traditional sliding mode control, so that the controller can achieve faster and more accurate control. Description of the Drawings

[0014] Figure 1 is the overall structure diagram of the photovoltaic energy storage converter; Figure 2 is the control block diagram of the improved active disturbance rejection control method of the photovoltaic energy storage converter based on fractional-order complementary sliding mode of the present invention; Figure 3It is the control schematic diagram of the improved active disturbance rejection control method of the photovoltaic energy storage converter based on fractional-order complementary sliding mode of the present invention; Figure 4 It is the transient response diagram of the three-phase currents a, b, c and the DC bus voltage under the PI control strategy when the load power suddenly increases from 30 kw to 60 kw; Figure 5 It is the transient response diagram of the three-phase currents a, b, c and the DC bus voltage under the control method of the present invention when the load power suddenly increases from 30 kw to 60 kw; Figure 6 It is the transient response diagram of the three-phase currents a, b, c and the DC bus voltage under the PI control strategy when the load power suddenly decreases from 60 kw to -20 kw; Figure 7 It is the transient response diagram of the three-phase currents a, b, c and the DC bus voltage under the control method of the present invention when the load power suddenly decreases from 60 kw to -20 kw; Figure 8 It is the waveform diagram of the three-phase current output by the inverter; Figure 9 It is the harmonic analysis diagram of the grid-connected current under the PI control strategy; Figure 10 It is the harmonic analysis diagram of the grid-connected current under the control method of the present invention. Specific implementation manners

[0015] The present invention will be described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0016] Embodiment 1 This embodiment provides an improved active disturbance rejection control method for a photovoltaic energy storage converter based on fractional-order complementary sliding mode, which is used to control the latter-stage converter of the photovoltaic energy storage converter. The latter-stage converter includes a three-phase full-bridge inverter, LC filtering, grid-connected side and load. The overall structure of the photovoltaic energy storage converter is as Figure 1 shown, and it is mainly composed of a bidirectional DC-DC converter, a photovoltaic array, an energy storage battery, a three-phase full-bridge inverter, filtering, an AC load and a power distribution network. Among them, MPPT is the maximum power tracking technology, which is connected to the bus through the MPPT algorithm to achieve the maximum power tracking of the bus voltage. The energy storage system can achieve bidirectional energy flow with the bus through the DC converter. The latter-stage converter is composed of a three-phase full-bridge inverter part, a filtering part and a power distribution network part. The photovoltaic energy storage converter is composed of a bidirectional chopper and a three-phase full-bridge inverter. Among them, S 1 ~S 6 are the switching tubes of the three-phase converter; S 7 , S 8 are the switching tubes of the DC chopper, e a , e b ,e c is the grid-side phase voltage; C dc is the DC-side capacitor; L bat is the filter inductor of the DC chopper; u bat is the battery output voltage; i L is the battery output current, that is, the current flowing through the inductor L bat ; i out is the current input from the DC bus to the converter; i pv is the current output by the PV array after MPPT; S j represents the on / off status of the switching tubes of each bridge arm in the converter:

[0017] Such as Figure 2 shown, it is specifically implemented according to the following steps: Step 1: Construct an equivalent mathematical model of a three-phase full-bridge inverter; Step 2: Construct a mathematical model in the d-q axis rotating coordinate system through dq transformation based on the equivalent mathematical model constructed in Step 1; Step 3: Construct an active disturbance rejection control paradigm and design a reduced-order generalized proportional-integral observer; Step 4: The given active power and reactive power pass through the power outer loop to obtain the current reference values of the d-q axes of the current inner loop; Step 5: Construct an error term between the current reference value output by the power outer loop in Step 4 and the current value of the mathematical model in the d-q axis rotating coordinate system obtained in Step 2. Design a fractional-order complementary sliding surface based on the error term, and design a double power-law reaching law to improve the chattering phenomenon of the system to obtain a sliding mode controller; Step 6: Obtain the control output through the sliding mode controller, use SPWM modulation to obtain the duty cycle, and apply the duty cycle to the control of the switching tubes of the three-phase full-bridge inverter, so as to realize the signal control of the full-bridge switch.

[0018] Embodiment 2 This embodiment provides an improved active disturbance rejection control method for a photovoltaic-storage converter based on fractional-order complementary sliding mode. On the basis of Embodiment 1, Step 1 is specifically that the mathematical model of the three-phase full-bridge inverter in the photovoltaic-storage converter in the three-phase coordinate system is: (1) In formula (1), U ao ,U bo and U co are respectively the sum of the filter part voltages of the a, b, and c phases of the three-phase inverter and the grid-side voltage. R is the equivalent resistance. i a and i b and i c are respectively the output phase currents of the a, b, and c phases of the three-phase full-bridge inverter. L is the filter inductor on the AC side of the three-phase full-bridge inverter. e a and e b and e c are respectively the grid-side voltages of the a, b, and c phases.

[0019] Embodiment 3 This embodiment provides an improved active disturbance rejection control method for a photovoltaic energy storage converter based on fractional-order complementary sliding mode. On the basis of Embodiments 1-2, Step 2 is specifically as follows: Equation (1) is converted from a three-phase coordinate system to a two-phase rotating d-q coordinate system, and its mathematical model in the dq two-phase coordinate system is: (2) In Equation (2), R is the filter resistance of the three-phase full-bridge inverter. ω is the grid voltage angular frequency; u dr and u qr are respectively the output voltages on the d and q axes. u dr =s d u dc and u qr =s q u dc ; s d and s q are respectively the d and q axis switching functions; u dc is the DC bus voltage; e d and e q are the components of the grid voltage on the d and q axes; i Ld and i Lq are the components of the grid-side current on the d and q axes; Derive Equation (2) to transform it into a normal form that satisfies second-order active disturbance rejection: (3).

[0020] Example 4 This example provides an improved active disturbance rejection control method for a photovoltaic energy storage converter based on fractional-order complementary sliding mode. On the basis of Examples 1 - 3, step 3 is specifically as follows: Expand Equation (3) as follows: (4) In Equation (4), is the angular frequency of the grid voltage; Convert Equation (4) into the ADRC normal form to obtain: (5) In Equation (5), , b d , b q are the control quantity gains of the d-axis and q-axis respectively, F d , F q are the lumped disturbances of the equivalent d-axis and q-axis respectively. The lumped disturbance includes the unmodeled part, the coupling part, and the internal and external disturbances of the system. The expression of the lumped disturbance is: (6) Define the d-axis state variables , , , and the q-axis state variables are , , . Then the state-space equation of the system shown in Equation (4) is: (7) Design the reduced-order generalized proportional-integral observer RGPIO according to Equation (7) in the form of: (8) In Equation (8), β 1 , β 2 , β 3 > 0, all are the observer gains of the d-axis; h 1 , h 2 , h 3 > 0, all are the observer gains of the q-axis, z d1 ,z d2 and z d3 and z q1 and z q2 and z q3 are respectively x d2 and x d3 and 、x q2 and x q3 and observation values.

[0021] Example 5 This example provides an improved active disturbance rejection control method for a photovoltaic-storage converter based on fractional-order complementary sliding mode. On the basis of Examples 1-4, step 4 is specifically as follows Let the reference values of the active power and reactive power of the photovoltaic-storage converter be P ref and Q ref . When the photovoltaic-storage converter is running, the reference values of the inner-loop d-axis and q-axis currents i Ldref and i Lqref are respectively expressed as (9).

[0022] Example 6 This example provides an improved active disturbance rejection control method for a photovoltaic-storage converter based on fractional-order complementary sliding mode. On the basis of Examples 1-5, step 5 is specifically as follows For the deviation i Ld and i Lq after dq transformation and their reference values e 1 and e 2 are constructed to obtain (10) In formula (10), i Ldref is the reference value of i Ld , and i Lqref is the reference value of i Lq ; The operator representing fractional calculus is defined as: (11) In Equation (11), is the real part of is a real number and is the order of calculus; and t are the upper and lower limits of the operator respectively; According to the deviation value e 1 , e 2 design the fractional - order complementary sliding mode surfaces of the d - axis and q - axis as: s d , s q as: (12) In Equation (12), s dg , s qg are the generalized sliding mode surfaces of the dq - axis, s dc , s qc are the complementary sliding mode surfaces of the dq - axis; The generalized sliding mode surface of the dq - axis is defined as: (13) In Equation (13), s dg , s qg are the generalized sliding mode surfaces of the dq - axis, s dc , s qc are the complementary sliding mode surfaces of the dq - axis; The complementary sliding mode surface of the dq - axis is defined as: (14) Take the α - th time derivative of both sides of Equation (13) and Equation (14) to obtain: (15) From Equation (14) and Equation (15), it can be obtained that: (16) At this time, the Lyapunov function is defined as: (17) Take the α derivative of Equation (17), and according to Equation (13) - Equation (17), it is obtained that: (18) Therefore, the complementary fractional-order sliding mode controller is designed as follows: (19) From equation (18), we get u deq and u qeq as follows: (20) Introduce the double power-law reaching law: (21) In equation (21), , ; when s→0 in the double power-law reaching law, s>0, indicating that the controller can make the approaching speed of the system continuously decrease to 0 when approaching the sliding mode surface, avoiding the switching in the conventional reaching law, thus effectively eliminating the chattering of the sliding mode controller itself; Combining equation (20) and equation (21), we obtain the complete control law u dr , u qr as follows: (22).

[0023] As Figure 3 shown is the control diagram of the improved active disturbance rejection control method for the photovoltaic energy storage converter based on fractional-order complementary sliding mode of the present invention. The control method of the present invention has the following advantages: 1) The reduced-order generalized proportional integral observer adopted by the present invention does not require an accurate mathematical model and is applicable to devices with large circuit parameter variations. The ordinary generalized proportional integral observer is a high-order observer. In the case of being affected by random disturbances, the system can maintain a certain stability. However, the high-order observer will generate oscillations, affecting the control accuracy of the system. By reducing the order of the generalized proportional integral observer, it can better apply to the topology of the photovoltaic energy storage converter and improve its estimation accuracy.

[0024] 2) Aiming at the problems of discontinuous chattering and poor tracking accuracy of traditional sliding mode control, this paper designs a fractional-order complementary sliding mode to control the system. Compared with traditional sliding mode, the complementary sliding mode designs a sliding mode surface complementary to the generalized sliding mode surface, making the system slide along the intersection line of the two sliding mode surfaces, having a faster convergence speed and higher tracking accuracy. Theoretically, its tracking accuracy is half of that of the traditional sliding mode control method. On the basis of the complementary sliding mode, adding fractional order, combining the fractional calculus theory and the sliding mode control theory, makes the fractional-order sliding mode control have better robustness, self-adaptability and anti-interference ability, and can better handle various complex controls.

[0025] 3) The sliding mode control term is mainly used to achieve the stability of the system. By adjusting the output of the controller, the system state moves on the sliding mode surface. The reaching law term mainly realizes the rapid approach of the system. By adjusting the output of the controller, the system state rapidly approaches the desired state. The double power reaching law designed in the present invention has better chattering elimination ability compared with the traditional reaching law. When the system is about to reach the sliding mode surface, the reaching speed of this controller continuously decreases to 0, avoiding the switching in the conventional reaching law, thus eliminating the chattering of the sliding mode controller itself.

[0026] Experimental analysis To verify the effectiveness of the improved active disturbance rejection control method of the photovoltaic energy storage converter based on fractional-order complementary sliding mode of the present invention, a simulation circuit is built on the Hardware-In-the-Loop (HIL) experimental platform and compared and analyzed with the traditional PI control strategy. When the directions of voltage and current are the same, the power is defined as positive. The simulation parameters are set as shown in Table 1.

[0027] Table 1 Circuit parameters

[0028] As Figures 4 - 5 shown, under the two controls, when the load power suddenly changes, increasing from the stable output of 30 kW to 60 kW suddenly, the dynamic response of the three-phase inverter's AC side output power is caused. As Figure 4 known, the transition time under PI control is 18 ms. As Figure 5 known, the transition time of the control strategy used in this paper is 6 ms, and the convergence speed is improved compared with PI control.

[0029] As Figures 6 - 7 shown, under the two controls, when the load power suddenly changes, decreasing from the stable output of 60 kW to -20 kW suddenly, the dynamic response of the three-phase inverter's AC side output power is caused. As Figure 6 known, the transition time under PI control is 19 ms. As Figure 7 known, the transition time of the control strategy used in this paper is 13 ms, and the convergence speed is improved compared with PI control.

[0030] Figure 8 The grid-side current waveform under the control strategy of the present invention when the load power increases suddenly from 30 kW to 60 kW, then decreases suddenly from 60 kW to -10 kW, and then increases suddenly from -10 kW to 40 kW is shown. It can be seen that the current waveform is stable and there is no waveform distortion, and the AC current under the desired power can be achieved, verifying the feasibility of the control of the present invention.

[0031] As Figure 9 shown, the harmonic analysis of the grid-connected current of the energy storage converter under traditional PI control is shown, and the THD is 4.60%. Figure 10The harmonic analysis of the grid-connected current of the energy storage converter under the control of the present invention is shown, and the THD is 0.98%. By comparison, it can be seen that the control of the present invention has stronger harmonic suppression ability and improves the power quality of grid connection.

Claims

1. An improved auto-disturbance rejection control method for a photovoltaic storage converter based on fractional-order complementary sliding mode is used to control the subsequent converter of the photovoltaic storage converter, which includes a three-phase full-bridge inverter, LC Filtering, grid-connected side and load, characterized in that, Follow the steps below to implement it: Step 1: Construct an equivalent mathematical model of a three-phase full-bridge inverter; Step 2: Based on the equivalent mathematical model constructed in step 1, a mathematical model in the dq axis rotation coordinate system is constructed through dq transformation; Step 3: Construct the ADRC paradigm and design a reduced-order generalized proportional-integral observer; Step 4: The given active power and reactive power are passed through the power outer loop to obtain the current reference value of the dq axis of the current inner loop; Step 5: Design the fractional-order complementary sliding surface and the bi-power reaching law to construct the sliding mode controller; Step 6: Obtain the control output through the sliding mode controller, use SPWM modulation to get the duty cycle, and apply the duty cycle to the control of the three-phase full-bridge inverter switch tube, thereby realizing signal control of the full-bridge switch.

2. The improved active disturbance rejection control method for photovoltaic storage converter based on fractional-order complementary sliding mode according to claim 1 is characterized in that: The step 1 is specifically as follows: The mathematical model of the three-phase full-bridge inverter in the photovoltaic storage converter in the three-phase coordinate system is: （1） In formula (1), U ao , U bo , U co They are the sum of the voltage of the filter part of the three-phase inverter a, b, c phases and the voltage on the distribution network side. R is the equivalent resistance, i a , i b , i c They are the three-phase output currents of a, b, and c of the three-phase full-bridge inverter, L For the three-phase full-bridge inverter AC measurement filter inductor, e a , e b , e c They are the three-phase voltages a, b, and c on the grid-connected side respectively.

3. The improved active disturbance rejection control method for photovoltaic storage converter based on fractional-order complementary sliding mode according to claim 2 is characterized in that: The step 2 is specifically as follows: Convert equation (1) from the three-phase coordinate system to the two-phase rotating dq coordinate system, and the mathematical model in the dq two-phase coordinate system is: （2） In formula (2), R is the filter resistor of the three-phase full-bridge inverter, ω is the grid voltage angular frequency; u dr , u qr are the output voltages on the d and q axes respectively, u dr =s d u dc , u qr =s q u dc ;s d 、s q They are the d and q axis switching functions respectively; u dc is the bus voltage on the DC side; e d , e q is the component of the grid voltage on the d and q axes; i Ld , i Lq is the component of the grid-side current in the d and q axes; Deriving equation (2) transforms it into a paradigm that satisfies the second-order auto-disturbance rejection: （3）。 4. The improved active disturbance rejection control method for photovoltaic storage converter based on fractional-order complementary sliding mode according to claim 3 is characterized in that: The step 3 is specifically as follows: Expand equation (3) as follows: （4） In formula (4), is the grid voltage angular frequency; Converting equation (4) into ADRC form yields: （5） In formula (5), b d , b q are the d-axis and q-axis control quantity gains respectively, F d , F q are the equivalent d-axis and q-axis lumped disturbances respectively. The lumped disturbance includes the unmodeled part of the system, the coupled part, and the internal and external disturbances of the system. The lumped disturbance expression is: （6） Define the d-axis state variable , , , the q-axis state variable is , , , then the spatial state equation of the system shown in formula (4) is: （7） According to formula (7), the form of the reduced-order generalized proportional integral observer RGPIO is: （8） In formula (8), β 1, β 2, β 3>0, all are observer gains of d-axis; h 1, h 2, h 3>0, both are the observer gains of the q-axis, z d1 , z d2 , z d3 , z q1 , z q2 , z q3 They are x d2 , x d3 , 、x q2 , x q3 , Observed value of .

5. The improved active disturbance rejection control method for photovoltaic storage converter based on fractional-order complementary sliding mode according to claim 4 is characterized in that: Said .

6. The improved active disturbance rejection control method for photovoltaic storage converter based on fractional-order complementary sliding mode according to claim 4 is characterized in that: The step 4 is specifically as follows: Assume that the active power and reactive power reference values ​​of the photovoltaic power converter are P ref , Q ref When the solar storage converter is running, the inner ring d and q axis current reference values ​​are i Ldref , i Lqref Respectively expressed as: （9）。 7. The improved active disturbance rejection control method for photovoltaic storage converter based on fractional-order complementary sliding mode according to claim 6 is characterized in that: The step 5 is specifically as follows: After dq transformation i Ld , i Lq Deviation from its reference value e 1. e 2. Build: （10） In formula (10), i Ldref for i Ld The reference value of i Lqref for i Lq Reference value of The operator representing fractional calculus is defined as: （11） In formula (11), for The real part of is a real number, the order of calculus; and t are the upper and lower limits of the operator respectively; According to the deviation value e 1. e 2 Design of fractional-order complementary sliding surfaces of d-axis and q-axis s d , s q for: （12） In formula (12), s dg , s qg is the generalized sliding mode surface of dq axis, s dc , s qc is the complementary sliding surface of dq axis; The generalized sliding surface of the dq axis is defined as: （13） In formula (13), s dg , s qg is the generalized sliding mode surface of dq axis, s dc , s qc is the complementary sliding surface of dq axis; The complementary sliding surface of the dq axis is defined as: （14） Take the two sides of equation (13) and equation (14) respectively α The time derivative is: （15） From equation (14) and equation (15), we can get: （16） At this time, the Lyapunov function is defined as: （17） Take formula (17) α Derivative, according to equation (13) to equation (17), we get: （18） Therefore, the complementary fractional-order sliding mode controller is designed as: （19） From formula (18), we can get u deq , u qeq for: （20） Introduce the double power reaching law: （21） Combining equation (20) and equation (21) gives the complete control law u dr , u qr for: （22）。 8. The improved active disturbance rejection control method for photovoltaic storage converter based on fractional-order complementary sliding mode according to claim 7 is characterized in that: In the formula (21), , .

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