Alternating parallel flyback inverter based on ADRC control

Abstract

The invention discloses an alternating parallel flyback inverter based on ADRC control in the field of power electronic control. The alternating parallel flyback inverter comprises a current control module, a voltage control module and an active disturbance rejection controller. The current control module is used for sensing the output current of the flyback inverter and generating a corresponding control signal; the current control module adopts an ADRC control algorithm to predict and compensate the influence from load change and environmental interference. The ADRC can estimate and compensate the harmonic interference of the power grid in real time, so that the output voltage of the inverter is closer to a pure sinusoidal waveform, the interference of harmonic waves on the power grid and other equipment can be effectively reduced by accurately inhibiting the harmonic component of the power grid, the electric energy quality is improved, the ADRC has a relatively high response speed, the harmonic interference of the power grid can be detected and compensated in time, and the power grid harmonic interference can be effectively eliminated. The rapid response capability enables the inverter to rapidly adjust the output voltage, and ensures that the system can make a response in time when the harmonic wave of the power grid changes, thereby maintaining stable operation.

Description

Technical Field

[0001] The present invention relates to the field of power electronic control, and in particular to an alternating parallel flyback inverter based on ADRC control. Background Art

[0002] As a key device for converting DC to AC power, the inverter plays a vital role in energy systems. It efficiently converts DC power generated by renewable energy systems (such as solar and wind power generation) into AC power, enabling this energy to be smoothly integrated into existing power systems and grids. The inverter's function not only enables energy interconnection but also improves energy efficiency and reduces energy loss. To meet the ever-increasing demand for energy, inverter development focuses on improving efficiency, reducing size, enhancing reliability, and promoting intelligent applications. Inverters exist in various topologies, such as alternating parallel flyback inverters, resonant inverters, and multi-level inverters. However, due to the flyback inverter's advantages such as high efficiency and high energy density, the current trend in inverter development is towards alternating parallel flyback inverters. Alternating parallel flyback inverters are electronic devices used to convert DC power to AC power and are widely used in renewable energy generation systems, electric vehicles, and uninterruptible power supplies (UPS).

[0003] Due to the coordinated operation of multiple inverter modules, the system design and control of alternating parallel inverters are relatively complex. Precise timing and power balance control are required to ensure coordination and stable operation between modules. Traditional alternating parallel flyback inverters are typically controlled using proportional, integral, and derivative (PID) controllers or empirical parameter tuning methods. However, in practical applications, parameter adjustment often requires trial and error or empirical experience, which can be time-consuming and labor-intensive. In some cases, PID controllers cannot effectively handle the coupling effects of multiple-input, multiple-output (MIMO) systems. When there are cross-effects or mutual coupling in the system, PID controllers may not be able to effectively decouple and handle them. PID controllers have limited control effectiveness for nonlinear systems. When faced with nonlinear systems, PID controllers may not be able to adapt to the system's dynamic changes and nonlinear characteristics, resulting in reduced control performance.

[0004] Traditional methods require multiple system tests and parameter adjustments, making it difficult to maintain good control performance under varying loads and environmental conditions. Furthermore, they struggle to meet the requirements for load disturbance suppression and response speed, resulting in relatively poor disturbance immunity. When the system is subject to external disturbances, the PID controller may not respond promptly and effectively, resulting in degraded control performance. Furthermore, the PID controller has limited robustness to large changes in system parameters or nonlinear systems. If the system's properties change, the PID controller may not adapt to the new operating conditions, requiring parameter readjustment or the use of alternative control methods.

[0005] Therefore, those skilled in the art provide an alternating parallel flyback inverter based on ADRC control to solve the problems raised in the above background technology. Summary of the Invention

[0006] The object of the present invention is to provide an alternating parallel flyback inverter based on ADRC control to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] The alternating parallel flyback inverter based on ADRC control includes a current control module, a voltage control module and an active disturbance rejection controller. The current control module is used to sense the output current of the flyback inverter and generate a corresponding control signal. The current control module adopts the ADRC control algorithm to achieve precise control of the output current by predicting and compensating for the influence of load changes and environmental interference. The voltage control module is used to sense the output voltage of the flyback inverter and generate a corresponding control signal. The voltage control module adopts the ADRC control algorithm to achieve precise control of the output voltage by adaptively adjusting parameters and introducing a disturbance observer, and has good anti-interference capability. The active disturbance rejection controller is used to calculate and generate the final control signal based on the output signals of the current control module and the voltage control module. The active disturbance rejection controller comprehensively considers factors such as load changes, environmental interference and system dynamic characteristics to achieve high-precision and high-stability control of the flyback inverter.

[0009] As a further solution of the present invention: it also includes a photovoltaic module PV, a filter energy storage capacitor Cin, an interleaved parallel flyback circuit and a grid-connected circuit. The interleaved parallel flyback circuit includes a switch VT1, a switch VT2, a switch VT3, a switch VT4, a resonant capacitor structure Cs1 and a resonant capacitor structure Cs2. The switches VT1, VT2, VT3 and VT4 are connected in parallel with each other. The grid-connected circuit includes a transformer module consisting of a transformer T1 and a capacitor Lpl and a transformer T2 and a capacitor Lp2, which respectively constitute a flyback circuit, a full-bridge inverter circuit consisting of a switch tube Q1, a switch tube Q2, a switch tube Q3 and a switch tube Q4, and a rectifier diode VD1 and a rectifier diode VD2.

[0010] As a further solution of the present invention: the photovoltaic module PV is connected in parallel with the filter energy storage capacitor Cin, and the inverter uses force control and acceleration control to drive the inverter output.

[0011] As a further solution of the present invention: the switch tube Q1, the switch tube Q2, the switch tube Q3 and the switch tube Q4 are each composed of a switch device and an inductive element, such as an inductor and a diode, and perform periodic switching actions through PWM control.

[0012] The control method of the alternating parallel flyback inverter based on ADRC control monitors and compensates for the impact of load changes and environmental disturbances on the inverter output. By introducing an adaptive disturbance observer and adjusting parameters, the control method can monitor and estimate the impact of external disturbances on the inverter in real time. By compensating for the estimated disturbance, the controller can automatically adjust the output current and voltage to adapt to load changes and environmental changes. The control method includes the following steps:

[0013] S01. The alternating parallel flyback inverter is used as a second-order control system, and the expression to be controlled is:

[0014]

[0015] Among them, f(·) is the total disturbance that integrates the internal and external disturbances of the system, and the state variable x1=y is selected. Then equation (1) can be transformed into the following state equation:

[0016]

[0017] S02. Establish a tracking-differentiator (TD) of the alternating parallel flyback inverter and arrange the transition process, as shown in the following formula:

[0018]

[0019] The real controller can only process discrete models, so the equation (1.3) is discretized to obtain the following discrete expression:

[0020]

[0021] In the formula, x1 is the tracking signal of the input signal v; x2 is the differential signal of x1; h is the sampling period; r0 determines the tracking speed of the signal; it filters the noise of the signal; fhan() is a fastest synthesis function, which is used to better arrange the transition process of the reference signal so that it does not overshoot. The specific form is as follows:

[0022]

[0023] S03. Using the output of the tracking differentiator as the error, a nonlinear state error feedback control law is constructed:

[0024] u0=β1fal(e1,a1,δ)+β2fal(e2,a2,δ)(0.15)

[0025] Where e1 is the error signal; e2 is the error differential signal; β1, β2, α1, α2 are the controller adjustable parameters; fal() is a nonlinear function, and the expression of fal() is as follows:

[0026]

[0027] S04. Finally, an extended state observer is constructed for the controller to observe the change law of the system control target. The observer expression is as follows:

[0028]

[0029] Similarly, the obtained extended state observer is discretized, and the expression of the discretized extended state observer is as follows:

[0030]

[0031] In the control of alternating parallel flyback inverters, the ADRC method can be applied to the coordination and control of each inverter module. By collecting the feedback signal of the system and estimating the disturbance, the ADRC controller can calculate the control quantity of the inverter module in real time to achieve the purpose of stable operation and coordinated work.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. High-precision harmonic compensation: ADRC can estimate and compensate for grid harmonic interference in real time, making the inverter's output voltage closer to a pure sine waveform. By accurately suppressing the grid's harmonic components, it can effectively reduce the interference of harmonics on the grid and other equipment, and improve power quality.

[0034] 2. Fast response capability: ADRC has a fast response speed and can detect and compensate for grid harmonic interference in a timely manner. This fast response capability enables the inverter to quickly adjust the output voltage, ensuring that the system can respond in time when the grid harmonics change and maintain stable operation.

[0035] 3. Good robustness: Since the frequency and amplitude of power grid harmonic interference may change, traditional control methods may not be able to handle harmonic disturbances of varying amplitude and frequency. ADRC has strong robustness and can adapt to harmonic disturbances of different frequencies and amplitudes to maintain stable control performance.

[0036] 4. Adaptability and self-adaptation: ADRC estimates the model parameters of the system and harmonic interference in real time through an adaptive observer, thereby improving the controller's adaptability to harmonic interference. This adaptive capability enables ADRC to cope with harmonic interference of different types and amplitudes, providing a more flexible and reliable control strategy. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of the present invention;

[0038] Figure 2 It is the logic block diagram of the ADRC controller in the present invention;

[0039] Figure 3 It is the logic framework of the controller in the present invention;

[0040] Figure 4 The primary and secondary current waveforms of the flyback inverter in the BCM working mode of the present invention are shown. DETAILED DESCRIPTION

[0041] See also Figures 1-4 In an embodiment of the present invention, an alternating parallel flyback inverter based on ADRC control includes a current control module, a voltage control module and an active disturbance rejection controller; the current control module is used to sense the output current of the flyback inverter and generate a corresponding control signal; the current control module adopts an ADRC control algorithm to achieve precise control of the output current by predicting and compensating for the influence of load changes and environmental interference; the voltage control module is used to sense the output voltage of the flyback inverter and generate a corresponding control signal; the voltage control module adopts an ADRC control algorithm to achieve precise control of the output voltage by adaptively adjusting parameters and introducing a disturbance observer, and has good anti-interference capability; the active disturbance rejection controller is used to calculate and generate a final control signal based on the output signals of the current control module and the voltage control module; the active disturbance rejection controller comprehensively considers factors such as load changes, environmental interference and system dynamic characteristics, and achieves high-precision and high-stability control of the flyback inverter.

[0042] Furthermore, it also includes a photovoltaic component PV, a filter energy storage capacitor Cin, an interleaved parallel flyback circuit and a grid-connected circuit. The interleaved parallel flyback circuit includes a switch VT1, a switch VT2, a switch VT3, a switch VT4, a resonant capacitor structure Cs1 and a resonant capacitor structure Cs2. The switch VT1, the switch VT2, the switch VT3 and the switch VT4 are connected in parallel with each other. The grid-connected circuit includes a transformer module consisting of a transformer T1 and a capacitor Lpl and a transformer T2 and a capacitor Lp2, which respectively constitute a flyback circuit, a full-bridge inverter circuit consisting of a switch tube Q1, a switch tube Q2, a switch tube Q3 and a switch tube Q4, and a rectifier diode VD1 and a rectifier diode VD2.

[0043] The photovoltaic module PV is connected in parallel with the filter energy storage capacitor Cin, and the inverter uses force control and acceleration control to drive the inverter output.

[0044] Among them, the switching tube Q1, the switching tube Q2, the switching tube Q3 and the switching tube Q4 are each composed of a switching device and an inductive element, such as an inductor and a diode, and perform periodic switching actions through a PWM control method.

[0045] The control method of the alternating parallel flyback inverter based on ADRC control achieves more accurate and stable current and voltage control by monitoring and compensating the impact of load changes and environmental interference on the inverter output. In this system, by introducing an adaptive disturbance observer and adjustment parameters, the impact of external disturbances on the inverter is monitored and estimated in real time. By compensating for the estimated disturbance, the controller can automatically adjust the output current and voltage to adapt to load changes and environmental changes, thereby improving the control performance and stability of the system. In addition, the system also uses force control and acceleration control to drive the inverter output to achieve more accurate power conversion and power output. The force control method can load appropriate voltage and current at the inverter output according to the position, velocity and acceleration of the target object to achieve the effect of accurately controlling the object reception. The acceleration control method can adjust the acceleration of the inverter output according to the feedback signal, thereby further improving the dynamic response and control stability of the system.

[0046] By estimating and offsetting system disturbances, precise control is achieved. In the control of an alternating parallel flyback inverter, the ADRC method can be applied to improve the system's robustness, response speed, and load disturbance rejection capabilities. It can be applied in multiple fields of power electronics technology, such as inverter control, grid stability, and motor drives. An alternating parallel flyback inverter is a power system with multiple modules operating in parallel, commonly used in renewable energy generation systems such as solar and wind power. This inverter system is efficient, reliable, and highly scalable, but the coordinated operation of multiple inverter modules makes control relatively complex. Traditional control methods often fail to meet system requirements. Therefore, the introduction of the ADRC control method can effectively overcome these problems. The core idea of ​​the ADRC control method is to establish a model to estimate and offset various system disturbances, enabling the controller to more accurately track the desired output. By applying ADRC control to the control of an alternating parallel flyback inverter, the stability and quality of the inverter's output voltage can be improved. Inverters are widely used in power systems to convert direct current into alternating current for power supply. However, the inverter's output is subject to interference from various internal and external factors, such as load fluctuations and grid voltage variations. ADRC can estimate and compensate for these disturbances in real time, making the inverter's output voltage more stable and improving power quality. In terms of grid stability, ADRC can be applied to control energy interactions between power plants and the grid. Frequency and voltage fluctuations exist in the grid, especially when large-scale renewable energy is integrated into the power system. ADRC can compensate for these disturbances in real time through rapid response and accurate disturbance estimation, maintaining grid frequency and voltage stability. Specifically, it involves the following steps:

[0047] S01. The alternating parallel flyback inverter is used as a second-order control system, and the expression to be controlled is:

[0048]

[0049] Among them, f(·) is the total disturbance that integrates the internal and external disturbances of the system, and the state variable x1=y is selected. Then equation (1) can be transformed into the following state equation:

[0050]

[0051] S02. Establish a tracking-differentiator (TD) of the alternating parallel flyback inverter and arrange the transition process, as shown in the following formula:

[0052]

[0053] The real controller can only process discrete models, so the equation (1.3) is discretized to obtain the following discrete expression:

[0054]

[0055] In the formula, x1 is the tracking signal of the input signal v; x2 is the differential signal of x1; h is the sampling period; r0 determines the tracking speed of the signal; it filters the noise of the signal; fhan() is a fastest synthesis function, which is used to better arrange the transition process of the reference signal so that it does not overshoot. The specific form is as follows:

[0056]

[0057] S03. Using the output of the tracking differentiator as the error, a nonlinear state error feedback control law is constructed:

[0058] u0=β1fal(e1,a1,δ)+β2fal(e2,a2,δ)(0.24)

[0059] Where e1 is the error signal; e2 is the error differential signal; β1, β2, α1, α2 are the controller adjustable parameters; fal() is a nonlinear function, and the expression of fal() is as follows:

[0060]

[0061] S04. Finally, an extended state observer is constructed for the controller to observe the change law of the system control target. The observer expression is as follows:

[0062]

[0063] Similarly, the obtained extended state observer is discretized, and the expression of the discretized extended state observer is as follows:

[0064]

[0065] In the control of alternating parallel flyback inverters, the ADRC method can be applied to the coordination and control of each inverter module. By collecting the feedback signal of the system and estimating the disturbance, the ADRC controller can calculate the control quantity of the inverter module in real time to achieve the purpose of stable operation and coordinated work.

[0066] The operating principle of the present invention is as follows: First, the input DC power supply is filtered and smoothed by an input inductor and a filter capacitor. Then, the DC voltage is distributed to multiple switching circuits. Each switching circuit consists of a switching device and an inductive element, such as an inductor and a diode. These switching devices perform periodic switching operations using PWM control. During operation, the switching devices in each switching circuit are alternately turned on and off, causing current to flow periodically between different switching circuits. Through reasonable current distribution, the total output current is shared among multiple switching circuits, thereby reducing the load on individual switching devices and improving system reliability. In addition, due to the parallel structure, even if one switching circuit fails, the other switching circuits can still operate normally, ensuring continuous power supply to the system. To achieve the synthesis of the output AC voltage, the switching devices in each switching circuit switch in a complementary manner, that is, when one is turned on, the other is turned off, achieving a flyback operation of the output voltage. The amplitude and frequency of the output AC voltage can be controlled by the PWM controller to switch the switching devices at high frequency.

[0067] During operation, the alternating parallel flyback inverter can operate in two different modes: Boundary Conduction Mode (BCM) and Discontinuous Conduction Mode (DCM). The choice of these two modes has a significant impact on the performance and efficiency of the inverter. In BCM mode, a portion of the inverter's load current always flows through zero during each switching cycle, meaning that the load current is never completely disconnected. This means that during each switching cycle, at least one switching device in the circuit is in the on state. In BCM mode, the inverter's operating frequency is typically higher, enabling smaller AC output ripple and higher power conversion efficiency. Furthermore, since the load current is always present, the design and selection requirements for inductor components are relatively low, reducing system cost. In DCM mode, the inverter's load current is disconnected for a period of time during each switching cycle, meaning that the current is zero at a certain moment. This means that during each switching cycle, all switching devices in the circuit are in the off state. In DCM mode, the inverter's operating frequency is typically lower, enabling larger AC output ripple. Due to the time it takes for the load current to be disconnected, higher requirements are placed on the design and selection of inductor components, and more consideration needs to be given to energy storage and output smoothness.

[0068] Furthermore, the ADRC controller proposed in the present invention enables the inverter to operate in both DCM and BCM modes at different times and under different conditions, thereby improving inverter efficiency. Under this hybrid control strategy, an interleaved parallel circuit is used to coordinate inverter operation. When sunlight is weak, the inverter operating power is low, so the inverter main circuit operates in DCM mode, and the slave circuit is not operated. As sunlight increases, the inverter operating power increases but does not exceed the full-load power of the circuit. At this time, the inverter operates in BCM mode for the main circuit, and the slave circuit is not operated. However, when the inverter power continues to increase and meets the conditions for full-load operation, the main and slave circuits begin operating simultaneously, with the slave circuit operating exclusively in BCM mode. This hybrid use of these two modes not only improves inverter efficiency but also reduces hardware circuit losses. The flyback inverter can operate in both modes, ensuring that the switch reduces the primary current to zero within each cycle and that no losses are incurred when it is turned on again.

[0069] When a flyback inverter operates solely in BCM mode, the transformer's conversion efficiency is significantly improved compared to other modes. However, if BCM is used throughout the entire switching cycle, the switching frequency will increase rapidly when the voltage pin is small or large. This will increase switching losses in the long term and compromise inverter conversion efficiency and output power quality. When the inverter operates solely in DCM mode, the switching frequency remains constant with grid power, effectively reducing switching losses. However, in high-power inverters, prolonged operation in DCM prevents the switching frequency from adjusting to grid power, reducing inverter efficiency and resulting in significant power loss. Therefore, to ensure inverter output quality, the inverter must be able to switch freely between BCM and DCM. When the inverter operates in BCM, the transformer's power conversion density is higher and the THD of the grid-connected current is lower. However, in BCM mode, the switching frequency tracks grid power changes in real time. Therefore, when the potential angle is very small or very large within a cycle, the switching frequency is very high. When the potential angle is in the middle of the cycle, the switching frequency is very low. By using interleaved parallel technology, the inverter operates in single flyback BCM mode at low electrical angles and in interleaved flyback BCM mode at high electrical angles.

[0070] The formula for the average current on the secondary side of the transformer contains a distortion factor. At this time, the grid-connected current output by the inverter is no longer a standard sine wave. Therefore, under certain input voltage conditions, the inverter operates in BCM mode, which will cause the THD value to be too large. In this case, connecting the inverter to the grid will cause serious pollution to the grid.

[0071] The ADRC in the present invention can estimate and compensate for grid harmonic interference in real time, making the output voltage of the inverter closer to a pure sine waveform. By accurately suppressing the harmonic components of the grid, the interference of harmonics on the grid and other equipment can be effectively reduced, and the quality of electric energy can be improved; ADRC has a relatively fast response speed and can promptly detect and compensate for grid harmonic interference. This rapid response capability enables the inverter to quickly adjust the output voltage, ensuring that the system can respond promptly when the grid harmonics change and maintain stable operation; because the frequency and amplitude of the grid harmonic interference may change, traditional control methods may not be able to handle harmonic disturbances of varying amplitude and frequency. However, ADRC has strong robustness and can adapt to harmonic interferences of different frequencies and amplitudes, maintaining stable control performance; ADRC estimates the model parameters of the system and harmonic interference in real time through an adaptive observer, thereby improving the adaptability of the controller to harmonic interference. This adaptive capability enables ADRC to cope with harmonic interferences of different types and amplitudes, providing a more flexible and reliable control strategy.

Claims

1. Alternating parallel flyback inverter based on ADRC control, characterized by: It includes a current control module, a voltage control module and an active disturbance rejection controller; The current control module is used to sense the output current of the flyback inverter and generate a corresponding control signal; the current control module adopts the ADRC control algorithm to achieve precise control of the output current by predicting and compensating for the influence of load changes and environmental interference; the voltage control module is used to sense the output voltage of the flyback inverter and generate a corresponding control signal; the voltage control module adopts the ADRC control algorithm to achieve precise control of the output voltage by adaptively adjusting parameters and introducing a disturbance observer; the active disturbance rejection controller is used to calculate and generate the final control signal based on the output signals of the current control module and the voltage control module; the active disturbance rejection controller comprehensively considers factors such as load changes, environmental interference and system dynamic characteristics, and achieves high-precision and high-stability control of the flyback inverter.

2. Alternating parallel flyback inverter based on ADRC control, characterized by: It also includes a photovoltaic component PV, a filter energy storage capacitor Cin, an interleaved parallel flyback circuit and a grid-connected circuit. The interleaved parallel flyback circuit includes a switch VT1, a switch VT2, a switch VT3, a switch VT4, a resonant capacitor structure Cs1 and a resonant capacitor structure Cs2. The switches VT1, VT2, VT3 and VT4 are connected in parallel with each other. The grid-connected circuit includes a transformer module consisting of a transformer T1 and a capacitor Lpl and a transformer T2 and a capacitor Lp2, which respectively constitute a flyback circuit, a full-bridge inverter circuit consisting of a switch tube Q1, a switch tube Q2, a switch tube Q3 and a switch tube Q4, and a rectifier diode VD1 and a rectifier diode VD2.

3. The alternating parallel flyback inverter based on ADRC control according to claim 2, characterized in that: The photovoltaic module PV is connected in parallel with the filter energy storage capacitor Cin. The inverter uses force control and acceleration control to drive the inverter output.

4. The alternating parallel flyback inverter based on ADRC control according to claim 2, characterized in that: The switching tubes Q1 , Q2 , Q3 and Q4 are each composed of a switching device and an inductive element, such as an inductor and a diode, and perform periodic switching actions through PWM control.

5. A control method for an alternating parallel flyback inverter based on ADRC control, applied to the alternating parallel flyback inverter based on ADRC control according to any one of claims 1 to 4, characterized in that: By monitoring and compensating for the impact of load changes and environmental disturbances on the inverter output, and by introducing an adaptive disturbance observer and adjusting parameters, the impact of external disturbances on the inverter can be monitored and estimated in real time. By compensating for the estimated disturbance, the controller can automatically adjust the output current and voltage to adapt to load changes and environmental changes. The specific steps include: S01. The alternating parallel flyback inverter is used as a second-order control system, and the expression to be controlled is: Among them, f(·) is the total disturbance that integrates the internal and external disturbances of the system, and the state variable x1=y, Then equation (1) can be transformed into the following state equation: S02. Establish a tracking-differentiator (TD) of the alternating parallel flyback inverter and arrange the transition process, as shown in the following formula: The real controller can only process discrete models, so the equation (1.3) is discretized to obtain the following discrete expression: Where x1 is the tracking signal of the input signal v; x2 is the differential signal of x1; h is the sampling period; r0 determines the tracking speed of the signal; it filters the noise of the signal; fhan() is a fastest synthesis function, which is used to better arrange the transition process of the reference signal so that it does not overshoot. The specific form is as follows: S03. Using the output of the tracking differentiator as the error, a nonlinear state error feedback control law is constructed: u0=β1fal(e1,a1,δ)+β2fal(e2,a2,δ)(0.6) Where e1 is the error signal; e2 is the error differential signal; β1, β2, α1, α2 are the controller adjustable parameters; fal() is a nonlinear function, and the expression of fal() is as follows: S04. Finally, an extended state observer is constructed for the controller to observe the change law of the system control target. The observer expression is as follows: Similarly, the obtained extended state observer is discretized, and the expression of the discretized extended state observer is as follows: In the control of alternating parallel flyback inverters, the ADRC method can be applied to the coordination and control of each inverter module. By collecting the feedback signal of the system and estimating the disturbance, the ADRC controller can calculate the control quantity of the inverter module in real time to achieve the purpose of stable operation and coordinated work.

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