Adaptive ADB-bang-bang current sharing control method and system for multiple multiphase buck-boost circuits connected in parallel

Abstract

The invention discloses a self-adaptive ADB-bang-bang current sharing control method and system for multiple multi-phase buck-boost circuits connected in parallel, relates to the field of DC micro-grids, and solves the technical problem of circulating current caused by sampling deviation and inconsistent parameters when a plurality of DC-DC boost converters are connected in parallel. According to the invention, a PI controller with conditional integration is introduced into a voltage outer loop controller of each converter, so that the voltage error of each converter is obtained; a switching function is obtained, and when the switching function is not changed, integral and proportional links are normally carried out; when the function is switched on and off, the output of the integrator is reset, the integral link of each PI controller is automatically closed and reset, and the upper and lower limit thresholds of hysteresis control are changed on line in real time; the operation stability of the DC micro-grid can be improved.

Description

Technical Field

[0001] This invention relates to the field of DC microgrids, specifically to an adaptive ADB-bang-bang current sharing control method and system for multiple multiphase buck-boost circuits in parallel. Background Technology

[0002] In DC microgrids, fluctuations in the DC bus voltage directly reflect the system's power transmission information. Especially during off-grid operation, the DC bus voltage is not a fixed value but rather fluctuates within a range. Therefore, control strategies based on the DC bus voltage signal are commonly used in DC microgrid systems. Droop control, which characterizes the relationships between voltage and power, and voltage and current, is a simple and reliable option. Typically, in a DC microgrid, each DC unit is connected to the DC bus via a DC / DC converter. Here, the current is defined as positive when each unit outputs power to the microgrid; that is, the current is positive when the unit discharges and negative when it charges. Most DC / DC converters employ dual voltage and current closed-loop control. Therefore, the common implementation of droop control in DC microgrids is to add droop curve control outside the converter's dual voltage and current closed-loop control as an outer control loop to obtain the converter's output DC voltage reference value before performing dual voltage and current closed-loop control. Currently, droop control has become the most common solution for parallel operation of multiple converter modules.

[0003] However, in practical engineering applications, the multi-machine parallel scheme using droop control has an inherent and difficult-to-eliminate problem, namely the circulating current problem. Therefore, this invention proposes an adaptive ADB-bang-bang current sharing control method and system for multiple multiphase buck-boost circuits in parallel, which is used to solve the circulating current problem caused by sampling deviation and parameter inconsistency when multiple DC-DC boost converters are connected in parallel. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes an adaptive ADB-bang-bang current sharing control method and system for multiple multiphase buck-boost circuits in parallel, which is used to solve the technical problem of circulating current caused by sampling deviation and parameter inconsistency when multiple DC-DC boost converters are connected in parallel. This invention automatically shuts down and resets the integral links of each controller when the DC bus voltage enters the adaptive hysteresis interval, so that each converter behaves as a voltage source with the same positive output impedance in this interval and their open-circuit voltage is consistent. This eliminates the driving condition of zero-sum mode current in the parallel system from the control structure, and ensures that the circulating current is strictly zero or suppressed to a very small range under steady state, thus solving the above-mentioned problem.

[0005] To achieve the above objectives, a first aspect of the present invention provides an adaptive ADB-bang-bang current sharing control method for multiple multiphase buck-boost circuits in parallel, comprising: A PI controller with conditional integration is introduced into the voltage outer loop controller of each converter to obtain the voltage error of each converter. Get switch function When the switching function At that time, no changes will be made, and the points and ratio process will proceed as normal; When the switching function When the integrator output is cleared to zero, the integral circuit of each PI controller is automatically shut down and reset, and the upper and lower limit thresholds of the hysteresis control are changed online in real time.

[0006] Preferably, the PI controller with conditional integral satisfies the following formula: (1); In the formula, The converter number, This is the PI control output of the i-th converter in the frequency domain. This is the value obtained by subtracting the actual value from the reference value in the frequency domain. and A proportionality coefficient set manually; For the Laplace operator, it represents the basic unit of the control quantity after being transformed to the frequency domain by the Laplace transform.

[0007] Preferably, obtaining the voltage error of each converter includes: Based on number The converters are extracted sequentially, and the voltage error of the converters is determined according to the calculation formula (2); The calculation formula (2) is: (2); In the formula, For the voltage error of the converter, The droop control rated voltage is the voltage when there is no power. Buffer the output for voltage measurement. This is the current bus voltage. For the first Measurement error of the converter.

[0008] Preferably, the obtaining switch function ,include: Obtain the bus voltage; when the bus voltage is outside the adaptive hysteresis interval, then the switching function... ; When the bus voltage is not outside the adaptive hysteresis interval, the switching function The adaptive hysteresis interval is [ ], The lower threshold for adaptive hysteresis. The upper threshold of the adaptive hysteresis loop.

[0009] Preferably, the online real-time adjustment of the upper and lower thresholds of the hysteresis control includes: Set minimum stay time And determine the inertial constant of the busbar The hysteresis half-width is then determined by formula (5). ; Determine the smooth sign function And set the upper half-width of the adaptive hysteresis loop. and adaptive hysteresis lower half-width ; Based on the upper half-width of the adaptive hysteresis and adaptive hysteresis lower half-width The final adaptive hysteresis interval is obtained: (3); (4); The calculation formula (5) is: (5); In the formula, The current DC bus voltage slope, To switch time, For design reference inertia, i.e., under manually selected standard operating conditions .

[0010] Preferably, the setting of the minimum dwell time ,include: Get the current DC bus voltage slope Based on DC bus voltage slope Half width Limit it, based on the limited halfwidth Determine the minimum stay time The minimum residence time Satisfy the following formula: (6); In the formula, This represents the instantaneous value of the current DC bus slope.

[0011] Preferably, the step of obtaining the current DC bus voltage slope ,include: (7).

[0012] Preferably, the DC bus voltage slope is used as the basis for... Half width Limitations are imposed, including: Half width Satisfy the following formula: (8); (9); (10); In the formula, Minimum switching time is used to prevent frequent switching and ensure hysteresis duration; One sampling period is used to calculate an estimate of the voltage slope; This is the upper limit of the maximum allowable voltage deviation; The base dead zone width is typically taken as an appropriate amplification value for the peak values ​​of noise and ripple; The sum of the peak values ​​of ripple and noise is used as a reference value to determine the base dead zone width.

[0013] Preferably, the determination of the busbar inertia constant ,include: (11); In the formula, This represents the total capacitance of the DC bus. The rated power of a DC microgrid or DC parallel system.

[0014] Preferably, the function for determining the smooth sign is... And set the upper half-width of the adaptive hysteresis loop. and adaptive hysteresis lower half-width ,include: The smoothing sign function Satisfy the following formula: (12); In the formula, The slope noise scale is used. The slope of the DC bus voltage; Extracting directional gain According to the smooth sign function and directional gain Determine the upper half-width of the adaptive hysteresis loop and adaptive hysteresis lower half-width : (13); (14); In the formula, directional gain The value range is (0,1), which is the proportional coefficient used to control whether the hysteresis loop tightens or loosens when the voltage deviates from the reference value; For voltage error; Based on the current voltage error and DC bus voltage slope upper half-width of adaptive hysteresis and adaptive hysteresis lower half-width Limit the upper half-width of the adaptive hysteresis loop. and adaptive hysteresis lower half-width As the final adaptive hysteresis upper half-width and adaptive hysteresis lower half-width .

[0015] Preferably, the step based on the current voltage error and DC bus voltage slope upper half-width of adaptive hysteresis and adaptive hysteresis lower half-width Limitations are imposed, including: set up ;in, ; When the DC bus voltage is higher than the reference voltage and continues to rise: (15); When the DC bus voltage is higher than the reference voltage, but is decreasing: (16); When the DC bus voltage is lower than the reference voltage and continues to decrease: (17); When the DC bus voltage is lower than the reference voltage, but is rising: (18).

[0016] A second aspect of the present invention provides an adaptive ADB-bang-bang current sharing control system with multiple multiphase buck-boost circuits in parallel, comprising: a preliminary processing module and a dynamic threshold module; The preliminary processing module is used to introduce a PI controller with conditional integral into the voltage outer loop controller of each converter to obtain the voltage error of each converter. The dynamic threshold module is used to obtain the switching function. When the switching function At that time, no changes will be made, and the points and ratio process will proceed as normal; When the switching function When the integrator output is cleared to zero, the integral circuit of each PI controller is automatically shut down and reset, and the upper and lower limit thresholds of the hysteresis control are changed online in real time.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention obtains the voltage error of each converter by introducing a PI controller with conditional integration into the voltage outer loop controller of each converter; and obtains the switching function. When the switching function At that time, no changes are made, and the integral and proportional phases proceed normally; when the switching function... When the integrator output is cleared to zero, the integral circuit of each PI controller is automatically shut down and reset, and the upper and lower limit thresholds of the hysteresis control are changed online in real time. This solves the technical problem of circulating current caused by sampling deviation and parameter inconsistency when multiple DC-DC boost converters are connected in parallel, and improves the stability of DC microgrid operation.

[0018] 2. In this invention, when the bus voltage enters the hysteresis interval, the integral circuits of all parallel converters are immediately shut down and cleared to zero, leaving only the proportional control. This ensures that the open-circuit voltages of each converter within the hysteresis are strictly consistent, and the unique solution of the zero-sum mode is zero. This completely eliminates circulating current from a structural perspective, and even if the load is zero, there will be no self-circulating current. Traditional droop control cannot avoid circulating current. This invention is the first to ensure no circulating current at the control structure level through "hysteresis + integral reset".

[0019] 3. The upper and lower limits of the hysteresis loop are dynamically adjusted according to the rate of change of the bus voltage and the bus inertia. The limits are tightened when the load changes abruptly and relaxed when returning to steady state. A minimum dwell time is set to ensure that the bus voltage quickly returns to the hysteresis region and stays stably under dynamic disturbances, avoiding frequent switching or high-frequency jitter. This ensures that the non-circulating current operating region remains effective in dynamic environments. For the first time, the hysteresis loop is coupled with the physical characteristics of the bus, unifying dynamic performance, voltage regulation accuracy and non-circulating current control.

[0020] 4. By using pure hardware methods such as passive averaging nodes or local self-calibration, the bus voltage error signals of each controller in the hysteresis loop are made naturally consistent under no communication conditions, ensuring that the open-circuit voltages of all converters in the hysteresis loop are exactly the same, achieving strict zero circulating current or suppressing residual circulating current to a negligible range, avoiding reliance on master-slave or digital communication, and solving the circulating current problem of multi-machine parallel control for the first time under completely distributed and no communication conditions. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the operation steps of the present invention; Figure 2 This is a schematic diagram illustrating the operation steps of changing the upper and lower thresholds of hysteresis control according to the present invention. Figure 3 This is a schematic diagram of the system modules of the present invention. Detailed Implementation

[0023] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Please see Figure 1 The first aspect of this invention provides an adaptive ADB-bang-bang current sharing control method for multiple multiphase buck-boost circuits in parallel, comprising: A PI controller with conditional integration is introduced into the voltage outer loop controller of each converter to obtain the voltage error of each converter. Get switch function When the switching function At that time, no changes will be made, and the points and ratio process will proceed as normal; When the switching function When the integrator output is cleared to zero, the integral circuit of each PI controller is automatically shut down and reset, and the upper and lower limit thresholds of the hysteresis control are changed online in real time.

[0025] It is worth noting that, to balance bus voltage regulation accuracy and system dynamic performance, this invention dynamically adjusts the upper and lower limits of the hysteresis loop by estimating the bus voltage change rate and the equivalent inertia of the bus capacitance online: when the load changes abruptly or the bus inertia is small, the hysteresis loop automatically widens to prevent jitter caused by frequent switching in and out of the integrator; when the bus voltage returns to the reference value or the inertia is large, the hysteresis loop tightens to improve voltage regulation accuracy. In this way, the system ensures a fast response under large disturbances and guarantees zero circulating current and voltage quality in steady state. Simultaneously, the integrator is reconnected outside the dead zone to ensure long-term voltage regulation with zero steady-state error.

[0026] The ADB control method proposed in this invention eliminates the circulating current caused by the inherent error PI control integrator within the hysteresis control region by introducing hysteresis control. By appropriately setting the upper and lower limits of hysteresis control, the entire system can remain stable under DC bus load changes, preventing excessive jitter. This represents a significant improvement over traditional droop control. The technical effectiveness of eliminating circulating current is demonstrated below: 1. The theoretical verification of this invention is as follows: When the switching function At that time, the first Taiwan PI controller degenerates into pure proportional controller The Thevenin equivalent of the closed-loop connection to the busbar side is: (twenty one); In the formula, The transfer function for the duty cycle to bus voltage of each converter power stage (typical Boost converter transfer function). The output impedance of each converter (output impedance in the small-signal model of the power stage). For voltage error; make (twenty two); In the formula, This is the adaptive hysteresis gain coefficient, used to control the sensitivity of the inertia-slope effect to the hysteresis. The equivalent impedance of the closed-loop port of each converter (in the dead zone, it is equivalent to a positive impedance value to avoid circulating current). exist That is, it degrades to the following under DC or low-frequency conditions: (twenty three); In the formula, It is the first hysteresis loop. The DC error of each DC / DC converter is different, and the voltage measurement buffer output of each controller is also affected. Through equivalent resistor Connect a high-impedance buffer node ; By Kirchhoff's Current Law: (twenty four); Each converter station is used uniformly within the hysteresis loop. As the input for bus voltage measurement, the error signals of each converter within the hysteresis loop are: (25); Substituting the open-circuit voltage back, we get: (26); In the formula, For the first The open-circuit voltage of each converter (within the dead zone, the voltage of each converter is the same); In engineering practice, every DC / DC converter has sampling errors. Therefore, the following derivation addresses these sampling errors. The bias can be zeroed out through local hardware calibration on each unit. Reduce to the smallest possible size; Assuming it has been zero since then Within the hysteresis loop, control is performed using ADB. Entering the hysteresis loop, the integral is cleared and disabled, meaning there is no DC integral bias; where, The baseline for hysteresis noise; Errors are used locally by each ,have to: (27); Differential open circuit voltage Amplitude less than or equal to Substituting into the parallel system and the KCL expression, we can obtain the upper bound of the circulation: (28); When from zero Reduced to the mV level, while When the current is above several hundred mΩ, the order of magnitude of the circulating current is extremely small, which is equivalent to no circulating current in engineering.

[0027] 2. The theoretical verification of this invention is as follows: Port equations after incorporating line impedance: Incorporating the DC resistance of the line, we obtain the first... DC port relationship from the station to the bus: (29); In the formula, This refers to the external line impedance of the converter or the virtual impedance after applying virtual impedance droop control. For the first The instantaneous output current of the converter on the bus side; remember (30); In the formula, For the first The overall equivalent impedance of the converter is determined by its internal resistance. With external wiring resistor or droop resistor Joint decision; Therefore, the first hysteresis loop... The DC port equation of the platform is: (31); Bundle Substitute (31) into the parallel KCL: (32); In the formula, This refers to the DC load current (the load current supplied through the parallel converter). The unique solution is: (33); then: That is, no intrinsic circulation under no-load conditions; like That is, complete uniform flow; Since the zero-sum mode is always 0, the absence of circulation is strictly true.

[0028] 3. The theoretical verification of this invention is as follows: Outside the hysteresis region, there exists an integral term that returns to the inside of the hysteresis region, as proven below: Hysteresis outside Each PI controller uses the same error channel; the n PI controllers are then superimposed. (34); In the formula, The sum of the PI control outputs of n converters; In terms of the monotonicity and capability margin of Boost, And exist make In this case, take the Lyapunov function: (35); In the formula, is the Lyapunov function, a scalar function used in Lyapunov's second method to construct and determine the stability of a system.

[0029] achievable , Since it is related to the loop gain, it can be seen that the system will enter the hysteresis interval in a finite time, and the above derivation of the hysteresis interval applies.

[0030] Adaptive hysteresis satisfies To ensure minimum residence time, the system remains in the non-circulating region within the hysteresis loop for most of the steady-state time; among which, This represents the rate of change of bus voltage.

[0031] The PI controller with conditional integral in this application satisfies the following formula: (1); In the formula, The converter number, This is the PI control output of the i-th converter in the frequency domain. This is the value obtained by subtracting the actual value from the reference value in the frequency domain. and A proportionality coefficient set manually; For the Laplace operator, it represents the basic unit of the control quantity after being transformed to the frequency domain by the Laplace transform.

[0032] This application obtains the voltage error of each converter, including: Based on number The converters are extracted sequentially, and the voltage error of the converters is determined according to the calculation formula (2); The calculation formula (2) is: (2); In the formula, For the voltage error of the converter, The droop control rated voltage is the voltage when there is no power. Buffer the output for voltage measurement. This is the current bus voltage. For the first Measurement error of the converter.

[0033] This application obtains the switching function. ,include: Obtain the bus voltage; when the bus voltage is outside the adaptive hysteresis interval, then the switching function... ; When the bus voltage is not outside the adaptive hysteresis interval, the switching function The adaptive hysteresis interval is [ ], The lower threshold for adaptive hysteresis. The upper threshold of the adaptive hysteresis loop.

[0034] Please see Figure 2 The online real-time adjustment of the upper and lower thresholds of hysteresis control in this application includes: Set minimum stay time And determine the inertial constant of the busbar The hysteresis half-width is then determined by formula (5). ; Determine the smooth sign function And set the upper half-width of the adaptive hysteresis loop. and adaptive hysteresis lower half-width ; Based on the upper half-width of the adaptive hysteresis and adaptive hysteresis lower half-width The final adaptive hysteresis interval is obtained: (3); (4); The calculation formula (5) is: (5); In the formula, The current DC bus voltage slope, To switch time, For design reference inertia, i.e., under manually selected standard operating conditions .

[0035] It should be noted that in common engineering applications, there are requirements for the voltage fluctuation range and response rate of the DC bus. Although fixed upper and lower limit hysteresis control can eliminate most of the circulating current, it can still cause excessive fluctuation and oscillation of the DC bus when the DC bus load is too large or the load switching is too fast. Therefore, this invention proposes an adaptive hysteresis with conditional integral reset (ADB) control method, which adjusts the hysteresis region by changing the upper and lower limit thresholds of the hysteresis control online in real time to obtain the best match with the load.

[0036] It should be noted that the core of ADB is to... , Change to adaptive halfwidth; at the same time, to avoid frequent switching, a minimum dwell time needs to be set. This refers to the shortest time spent in the hysteresis region.

[0037] It should be noted that the hysteresis half-width was defined during the initial stage of system operation. for: ; In the formula, = ; The maximum value of the hysteresis half-width is usually determined based on the maximum limit of voltage variation in the system or engineering requirements. The base dead zone width is typically chosen as an appropriate amplification value for the peak values ​​of noise and ripple. Weighting coefficients set manually; .

[0038] This application sets a minimum stay time. ,include: Get the current DC bus voltage slope Based on DC bus voltage slope Half width Limit it, based on the limited halfwidth Determine the minimum stay time The minimum residence time Satisfy the following formula: (6); In the formula, This represents the instantaneous value of the current DC bus slope.

[0039] This application obtains the current DC bus voltage slope. ,include: (7).

[0040] It should be noted that, ;in, The current total output power of the DC bus is instantaneous in the time domain.

[0041] This application is based on the DC bus voltage slope. Half width Limitations are imposed, including: Half width Satisfy the following formula: (8); (9); (10); In the formula, Minimum switching time is used to prevent frequent switching and ensure hysteresis duration; One sampling period is used to calculate an estimate of the voltage slope; This is the upper limit of the maximum allowable voltage deviation; The base dead zone width is typically taken as an appropriate amplification value for the peak values ​​of noise and ripple; The sum of the peak values ​​of ripple and noise is used as a reference value to determine the base dead zone width.

[0042] This application determines the busbar inertia constant. ,include: (11); In the formula, This represents the total capacitance of the DC bus. The rated power of a DC microgrid or DC parallel system.

[0043] It should be noted that, The inertial constant of the busbar is defined as follows: It is used to characterize the energy storage capacity and power response of a system.

[0044] This application determines the smoothing sign function. And set the upper half-width of the adaptive hysteresis loop. and adaptive hysteresis lower half-width ,include: The smoothing sign function Satisfy the following formula: (12); In the formula, The slope noise scale is used. The slope of the DC bus voltage; Extracting directional gain According to the smooth sign function and directional gain Determine the upper half-width of the adaptive hysteresis loop and adaptive hysteresis lower half-width : (13); (14); In the formula, directional gain The value range is (0,1), which is the proportional coefficient used to control whether the hysteresis loop tightens or loosens when the voltage deviates from the reference value; For voltage error; Based on the current voltage error and DC bus voltage slope upper half-width of adaptive hysteresis and adaptive hysteresis lower half-width Limit the upper half-width of the adaptive hysteresis loop. and adaptive hysteresis lower half-width As the final adaptive hysteresis upper half-width and adaptive hysteresis lower half-width .

[0045] It should be noted that when the voltage error When the DC bus voltage is higher than the reference voltage, only the upper half-width of the adaptive hysteresis loop is applied. Follow Scaling; when voltage error When the DC bus voltage is lower than the reference voltage, only the lower half-width of the adaptive hysteresis loop is applied. Follow Scaling.

[0046] This application is based on the current voltage error and DC bus voltage slope upper half-width of adaptive hysteresis and adaptive hysteresis lower half-width Limitations are imposed, including: set up ;in, ; When the DC bus voltage is higher than the reference voltage and continues to rise: (15); When the DC bus voltage is higher than the reference voltage, but is decreasing: (16); When the DC bus voltage is lower than the reference voltage and continues to decrease: (17); When the DC bus voltage is lower than the reference voltage, but is rising: (18).

[0047] It should be noted that when the DC bus voltage is higher than the reference voltage and continues to rise, it indicates that the DC bus is being moved away from, and the upper edge of the hysteresis loop is tightening. When the DC bus voltage is higher than the reference voltage, but rises, it indicates that it is returning to the DC bus, and the upper edge of the hysteresis loop widens. When the DC bus voltage is lower than the reference voltage and continues to decrease, it indicates that the DC bus is being moved away from, and the lower edge of the hysteresis loop is tightening. When the DC bus voltage is lower than the reference voltage but rises, it indicates that the DC bus is returning to normal, and the lower edge of the hysteresis loop widens.

[0048] Please see Figure 3 The second aspect of the present invention provides an adaptive ADB-bang-bang current sharing control system with multiple multiphase buck-boost circuits in parallel, including: a preliminary processing module and a dynamic threshold module; Preliminary processing module: used to introduce a PI controller with conditional integral into the voltage outer loop controller of each converter to obtain the voltage error of each converter; Dynamic threshold module: used to obtain the switching function. When the switching function At that time, no changes will be made, and the points and ratio process will proceed as normal; When the switching function When the integrator output is cleared to zero, the integral circuit of each PI controller is automatically shut down and reset, and the upper and lower limit thresholds of the hysteresis control are changed online in real time.

[0049] Some of the data in the above formula are calculated by removing dimensions and taking their numerical values. The formula is the closest to the real situation obtained by software simulation of a large amount of collected data. The preset parameters and preset thresholds in the formula are set by those skilled in the art according to the actual situation or obtained through simulation of a large amount of data.

[0050] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. An adaptive ADB-bang-bang current sharing control method for multiple multiphase buck-boost circuits in parallel, characterized in that, include: A PI controller with conditional integration is introduced into the voltage outer loop controller of each converter to obtain the voltage error of each converter. Get switch function When the switching function At that time, no changes will be made, and the points and ratio process will proceed as normal; When the switching function When the integrator output is cleared to zero, the integral circuit of each PI controller is automatically shut down and reset, and the upper and lower limit thresholds of the hysteresis control are changed online in real time.

2. The adaptive ADB-bang-bang current sharing control method for multiple multiphase buck-boost circuits in parallel as described in claim 1, characterized in that, The PI controller with conditional integral satisfies the following formula: (1)； In the formula, The converter number, This is the PI control output of the i-th converter in the frequency domain. This is the value obtained by subtracting the actual value from the reference value in the frequency domain. and This is the proportionality coefficient. For the Laplace operator.

3. The adaptive ADB-bang-bang current sharing control method for multiple multiphase buck-boost circuits in parallel according to claim 1, characterized in that, The acquisition of the voltage error of each converter includes: Based on number The converters are extracted sequentially, and the voltage error of the converters is determined according to the calculation formula (2); The calculation formula (2) is: (2)； In the formula, For the voltage error of the converter, The droop control rated voltage is the voltage when there is no power. Buffer the output for voltage measurement. This is the current bus voltage. For the first Measurement error of the converter.

4. The adaptive ADB-bang-bang current sharing control method for multiple multiphase buck-boost circuits in parallel as described in claim 1, characterized in that, The acquisition switch function ,include: Obtain the bus voltage; when the bus voltage is outside the adaptive hysteresis interval, then the switching function... ; When the bus voltage is not outside the adaptive hysteresis interval, the switching function The adaptive hysteresis interval is [ ], The lower threshold for adaptive hysteresis. The upper threshold of the adaptive hysteresis loop.

5. The adaptive ADB-bang-bang current sharing control method for multiple multiphase buck-boost circuits in parallel according to claim 1, characterized in that, The online real-time adjustment of the upper and lower thresholds of the hysteresis control includes: Set minimum stay time And determine the inertial constant of the busbar The hysteresis half-width is then determined by formula (5). ; Determine the smoothing sign function And set the upper half-width of the adaptive hysteresis loop. and adaptive hysteresis lower half-width ; Based on the upper half-width of the adaptive hysteresis and adaptive hysteresis lower half-width The final adaptive hysteresis interval is obtained: ) (3)； ) (4)； The calculation formula (5) is: (5)； In the formula, The current DC bus voltage slope. To switch time, For design reference inertia.

6. The adaptive ADB-bang-bang current sharing control method for multiple multiphase buck-boost circuits in parallel according to claim 5, characterized in that, The setting of minimum dwell time ,include: Get the current DC bus voltage slope Based on DC bus voltage slope Half width Limit it, based on the limited halfwidth Determine the minimum stay time The minimum residence time Satisfy the following formula: (6)； In the formula, This represents the instantaneous value of the current DC bus slope.

7. The adaptive ADB-bang-bang current sharing control method for multiple multiphase buck-boost circuits in parallel according to claim 6, characterized in that, The current DC bus voltage slope is obtained. ,include: (7)。 8. The adaptive ADB-bang-bang current sharing control method for multiple multiphase buck-boost circuits in parallel according to claim 6, characterized in that, The DC bus voltage slope Half width Limitations are imposed, including: Half width Satisfy the following formula: (8)； (9)； (10)； In the formula, To minimize the switching time, One sampling period; This is the upper limit of the maximum allowable voltage deviation; The base dead zone width is typically chosen as an appropriate amplification value for the peak values ​​of noise and ripple. The sum of the peak values ​​of ripple and noise.

9. The adaptive ADB-bang-bang current sharing control method for multiple multiphase buck-boost circuits in parallel according to claim 5, characterized in that, The determination of the busbar inertia constant ,include: (11)； In the formula, This represents the total capacitance of the DC bus. The rated power of a DC microgrid or DC parallel system.

10. The adaptive ADB-bang-bang current sharing control method for multiple multiphase buck-boost circuits in parallel according to claim 5, characterized in that, The function for determining the smooth sign And set the upper half-width of the adaptive hysteresis loop. and adaptive hysteresis lower half-width ,include: The smoothing sign function Satisfy the following formula: (12)； In the formula, The slope noise scale is used. The slope of the DC bus voltage; Extracting directional gain According to the smooth sign function and directional gain Determine the upper half-width of the adaptive hysteresis loop and adaptive hysteresis lower half-width : (13)； (14)； In the formula, directional gain The value range is (0,1), which is the proportional coefficient used to control whether the hysteresis loop tightens or loosens when the voltage deviates from the reference value; For voltage error; Based on the current voltage error and DC bus voltage slope upper half-width of adaptive hysteresis and adaptive hysteresis lower half-width Limit the upper half-width of the adaptive hysteresis loop. and adaptive hysteresis lower half-width As the final adaptive hysteresis upper half-width and adaptive hysteresis lower half-width .

11. The adaptive ADB-bang-bang current sharing control method for multiple multiphase buck-boost circuits in parallel according to claim 10, characterized in that, According to the current voltage error and DC bus voltage slope upper half-width of adaptive hysteresis and adaptive hysteresis lower half-width Limitations are imposed, including: set up ;in, ; When the DC bus voltage is higher than the reference voltage and continues to rise: (15)； When the DC bus voltage is higher than the reference voltage, but is decreasing: (16)； When the DC bus voltage is lower than the reference voltage and continues to decrease: (17)； When the DC bus voltage is lower than the reference voltage, but is rising: (18)。 12. An adaptive ADB-bang-bang current sharing control system for multiple multiphase buck-boost circuits in parallel, used to operate the adaptive ADB-bang-bang current sharing control method for multiple multiphase buck-boost circuits in parallel as described in any one of claims 1 to 11, characterized in that, include: Preliminary processing module and dynamic threshold module; The preliminary processing module is used to introduce a PI controller with conditional integral into the voltage outer loop controller of each converter to obtain the voltage error of each converter. The dynamic threshold module is used to obtain the switching function. When the switching function At that time, no changes will be made, and the points and ratio process will proceed as normal; When the switching function When the integrator output is cleared to zero, the integral circuit of each PI controller is automatically shut down and reset, and the upper and lower limit thresholds of the hysteresis control are changed online in real time.

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