A converter current sharing control method, system, device and medium

Abstract

This invention discloses a converter current sharing control method, system, device, and medium. A first state-space model is constructed based on the converter's topology. The first state-space model is transformed by introducing the difference and sum of the two-phase inductor currents to obtain a second state-space model. Based on the linear relationship between the output voltage change rate and the sum of the two-phase inductor currents, and the linear relationship between the difference of the two-phase inductor currents and the output voltage, the second state-space model is decoupled into an inductor current regulation subsystem and a voltage regulation subsystem, used to construct a third state-space model of the switching affine system. A minimum projection controller is designed based on the linear matrix inequality of the Lyapunov function constructed from the third state-space model to generate control signals to control the power switch to regulate the output voltage and achieve current sharing. The method provided in this application provides precise current sharing control, rapid voltage regulation, and stability during input voltage jumps or reference voltage changes.

Description

Technical Field

[0001] This invention relates to the field of electronic device control technology, and in particular to a converter current sharing control method, system, device and medium. Background Technology

[0002] With the continuous growth in demand for high-efficiency power conversion in modern electronic devices, especially in fields such as data centers, distributed energy, and electric vehicles, the requirements for high-power, high-efficiency power supplies are becoming increasingly stringent. Traditional single DC-DC converters, due to limitations in power devices, are difficult to meet the needs of high-power applications. Therefore, parallel operation of two-phase or multi-phase DC-DC converters has become a common solution. By operating in parallel, not only can the output power be increased, but the stress on switching devices can also be reduced, thereby improving efficiency and reliability.

[0003] Two-phase interleaved parallel Buck converters are DC-DC converters with output voltage lower than input voltage, widely used in various low-voltage electronic devices. In practical applications, due to component parameter mismatch and wiring impedance differences, imbalances in inductor current across phases can easily occur, leading to overload on single-phase converters, resulting in overheating, increased losses, and even shortened converter lifespan. Therefore, effective current sharing control of the inductor current in each phase directly affects the converter's stability, efficiency, and lifespan.

[0004] In existing technologies, current sharing control is a key technology for achieving reliability and stable performance in two-phase interleaved parallel Buck converters. This method allocates the inductor current of each phase in the parallel module in real time to ensure that the current allocated to each phase of the converter matches the demand. However, existing current sharing control methods have some drawbacks: they are highly dependent on the main module, which can easily lead to single-point failures; the current sharing accuracy is affected when the load changes significantly; and the flexibility of current sharing control is poor for complex circuit designs.

[0005] Therefore, it is evident that improving the accuracy and flexibility of current sharing control while achieving output voltage regulation has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] This invention provides a converter current sharing control method and system to solve the technical problem of improving the accuracy and flexibility of current sharing control while achieving output voltage regulation. The controller is designed by constructing a switching affine system by decoupling inductor current and voltage, thereby improving the accuracy and flexibility of current sharing control while ensuring system stability and reducing dependence on the main module.

[0007] In a first aspect, the present invention provides a converter current sharing control method, the method being applied to a Buck converter with a constant current source load and two phases interleaved in parallel, the method comprising:

[0008] Based on the topology of the constant current source load two-phase interleaved parallel Buck converter and the rate of change of inductor current and output voltage of each phase of the topology, a first state-space model is constructed.

[0009] The state variables of the first state space model are transformed by introducing the difference between the two-phase inductor currents and the sum of the two-phase inductor currents to obtain the second state space model.

[0010] Based on the linear relationship between the output voltage change rate and the sum of the two-phase inductor currents, and the linear relationship between the difference between the two-phase inductor currents and the output voltage, the second state-space model is decoupled into an inductor current regulation subsystem and a voltage regulation subsystem using input transformation; the state variable of the inductor current regulation subsystem is the output voltage, and the state variable of the voltage regulation subsystem is a matrix composed of the output voltage and the sum of the two-phase inductor currents;

[0011] Based on the inductor current regulation subsystem and the voltage regulation subsystem, a third state space model of the switching affine system is constructed.

[0012] Based on the third state space model, the Lyapunov function of the switching affine system is constructed, and the minimum projection controller is designed according to the linear matrix inequality of the Lyapunov function.

[0013] Based on the aforementioned minimum projection controller, a distributed minimum projection switch technique is used to generate control signals;

[0014] The power switch is controlled by the control signal to adjust the output voltage and achieve current sharing control.

[0015] Preferably, the construction of the first state-space model based on the topology of the two-phase interleaved parallel Buck converter with the constant current source load and the rate of change of inductor current and output voltage of each phase of the topology includes:

[0016] Based on the topology of the constant current source load two-phase interleaved parallel Buck converter, the first state variable of the constant current source load two-phase interleaved parallel Buck converter is selected. The first state variable includes the first inductor current of the first phase converter, the second inductor current of the second phase converter, and the output voltage.

[0017] Based on the first state variable, a first state space model of the topology is constructed. The first state space model includes a first inductor current rate of change equation, a second inductor current rate of change equation, and an output voltage rate of change equation.

[0018] Preferably, the step of decoupling the second state-space model into an inductor current regulation subsystem and a voltage regulation subsystem by input transformation based on the linear relationship between the output voltage change rate and the sum of the two-phase inductor currents, and the linear relationship between the difference between the two-phase inductor currents and the output voltage, includes:

[0019] In the second state space model, the voltage output and the sum of the two-phase inductor currents are changed into a matrix composed of the output voltage and the sum of the two-phase inductor currents, so as to decouple the second state space model into an inductor current regulation subsystem and a voltage regulation subsystem. The voltage regulation subsystem cannot receive the reverse signal of the inductor current regulation subsystem.

[0020] The model equation for the inductor current regulation subsystem is:

[0021]

[0022] The model equation for the voltage regulation subsystem is:

[0023]

[0024] Where z1(t) represents the difference in inductor current between the first and second phase converters at time t, z2(t) represents the sum of the inductor currents between the first and second phase converters at time t, z3(t) is the output voltage at time t, E is the input voltage, S1(t) and S2(t) are the control signals for the first and second switching transistors at time t, respectively, and I... O L1 is the constant current source load current, C is the output capacitor, and L2 and L1 are the inductance values ​​of the first phase converter and the second phase converter, respectively.

[0025] Preferably, the step of constructing the Lyapunov function of the switched affine system based on the third state space model includes:

[0026] Based on the current difference between the two-phase inductors and the preset reference output voltage, a power switch control algorithm is designed. The power switch control algorithm is set to ensure that the output voltage tracks the reference output voltage to the maximum extent and that the current difference between the two-phase inductors approaches zero infinitely.

[0027] Based on the power switch control algorithm, the balance point of the switching affine system is obtained, and the set of switch balance points is obtained based on the balance point of the switching affine system.

[0028] Based on the third state space model and the set of switch equilibrium points, the Lyapunov function of the switching affine system is constructed.

[0029] Preferably, the Lyapunov function is:

[0030]

[0031] in, z e =[z1 e z2 e z3 e ] T ,z e To switch the equilibrium point of the affine system, z1 e z2 e and z3 e These represent the values ​​of z1, z2, and z3 when the affine system reaches its equilibrium point. For the voltage regulation subsystem Σ v The equilibrium point, where γ is the weighting factor for adjusting the flow sharing performance. Let be the positive definite matrix of the Lyapunov function.

[0032] Preferably, the step of designing the minimum projection controller based on the linear matrix inequality of the Lyapunov function includes:

[0033] The Lyapunov function is differentiated along the trajectory of the switched affine system, and the Lyapunov function index is obtained by substituting the equilibrium point of the switched affine system into the derivative.

[0034] A minimum projection controller is designed by selecting the portion of the Lyapunov function index related to switching transistor control. The minimum projection controller is as follows:

[0035]

[0036]

[0037] in, S represents the combined control signals of the first and second switching transistors;

[0038] Based on the equilibrium point of the switching affine system and the set of switching equilibrium points, construct the time rate of change equation of the switching affine system;

[0039] Based on the time rate of change equation, obtain the feedback gain matrix that controls the switching affine system to the equilibrium point. The feedback gain matrix is ​​used to reflect the switching balance relationship.

[0040] Substitute the feedback gain matrix into the Lyapunov function index, and transform the derivative along the trajectory of the switched affine system into a standard quadratic inequality;

[0041] The standard quadratic inequality is converted into a linear matrix inequality. The weighting factor is selected through circuit simulation, and the linear matrix inequality is solved to obtain a positive definite matrix that meets the positive definiteness requirement.

[0042] Preferably, based on the minimum projection controller, a distributed minimum projection switch technique is used to generate the control signal, including:

[0043] The control signal of the minimum projection controller is solved with the objective of maximizing the decrease of the Lyapunov function index.

[0044] The control signal is:

[0045]

[0046] Secondly, the present invention also provides a converter current sharing control system to implement the converter current sharing control method described above. The system is applied to a two-phase interleaved parallel Buck converter with a constant current source load. The system includes: a first state space model construction unit, a second state space model construction unit, an input transformation decoupling unit, a third state space model construction unit, a minimum projection controller design unit, a control signal generation unit, and a current sharing control unit.

[0047] The first state-space model construction unit is used to construct a first state-space model based on the topology of the constant current source load two-phase interleaved parallel Buck converter and the rate of change of inductor current and output voltage of each phase of the topology.

[0048] The second state space model construction unit is used to introduce the difference between two-phase inductor currents and the sum of the two-phase inductor currents to transform the state variables of the first state space model to obtain the second state space model.

[0049] The input transformation decoupling unit is used to decouple the second state-space model into an inductor current regulation subsystem and a voltage regulation subsystem based on the linear relationship between the output voltage change rate and the sum of the two-phase inductor currents, and the linear relationship between the difference between the two-phase inductor currents and the output voltage. The input variable of the inductor current regulation subsystem is the output voltage, and the input variable of the voltage regulation subsystem is a matrix composed of the output voltage and the sum of the two-phase inductor currents.

[0050] The third state space model construction unit is used to construct a third state space model of the switching affine system based on the inductor current regulation subsystem and the voltage regulation subsystem.

[0051] The minimum projection controller design unit is used to construct the Lyapunov function of the switching affine system based on the third state space model, and to design the minimum projection controller according to the linear matrix inequality of the Lyapunov function.

[0052] The control signal generation unit is used to generate control signals based on the minimum projection controller using distributed minimum projection switching technology;

[0053] The current sharing control unit is used to control the power switch using the control signal to adjust the output voltage and achieve current sharing control.

[0054] Thirdly, the present invention also provides a computer device, the computer device including a memory, a processor and a transceiver, which are connected to each other via a bus; the memory is used to store a set of computer program instructions and data, and to transmit the stored data to the processor, the processor executes the program instructions stored in the memory to execute the converter current sharing control method described above.

[0055] Fourthly, the present invention also provides a computer-readable storage medium storing a computer program that, when executed, implements the L-converter current sharing control method described above.

[0056] This invention provides a converter current sharing control method, system, device, and medium. Compared with the prior art, the beneficial effects of the embodiments of this invention are at least one of the following:

[0057] (1) It can achieve precise current sharing control and fast voltage regulation, ensuring that the constant current source load two-phase interleaved parallel Buck converter remains stable when the input voltage jumps or the reference voltage changes.

[0058] (2) The switching transistors of different converters are controlled independently, which greatly improves the scalability and robustness of the system and reduces the complexity and cost of the control system. Attached Figure Description

[0059] Figure 1 This is a schematic diagram of the steps of a converter current sharing control method provided in a preferred embodiment of the present invention;

[0060] Figure 2 This is a schematic diagram of a two-phase interleaved parallel Buck converter with a constant current source load provided in a preferred embodiment of the present invention;

[0061] Figure 3 This is a simulation circuit diagram of a constant current source load two-phase interleaved parallel Buck converter on PSIM provided in a preferred embodiment of the present invention;

[0062] Figure 4 This is a schematic diagram of the two-phase inductor current difference after adopting the converter current sharing control method provided in the embodiment of the present invention, according to a preferred embodiment of the present invention;

[0063] Figure 5 This is the output voltage waveform after employing the converter current sharing control method provided in this embodiment of the invention, as provided in a preferred embodiment of the invention.

[0064] Figure 6 This is a schematic diagram of the two-phase inductor current difference when the input voltage jumps from 12V to 24V, provided by a preferred embodiment of the present invention, using the converter current sharing control method provided in the embodiment of the present invention.

[0065] Figure 7 This is the output voltage waveform of the converter current sharing control method provided in a preferred embodiment of the present invention when the input voltage jumps from 12V to 24V.

[0066] Figure 8 This is a schematic diagram of the difference in inductor current between two phases when the reference voltage jumps from 8V to 5V, provided by a preferred embodiment of the present invention, using the converter current sharing control method provided by the embodiment of the present invention.

[0067] Figure 9 This is a preferred embodiment of the present invention, showing the output voltage waveform when the reference voltage jumps from 8V to 5V using the converter current sharing control method provided in this embodiment of the present invention.

[0068] Figure 10 This is a schematic diagram of a converter current sharing control system provided in a preferred embodiment of the present invention;

[0069] Figure 11 This is a schematic diagram of the structure of a computer device provided in one embodiment of the present invention. Detailed Implementation

[0070] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. The embodiments are provided for illustrative purposes only and should not be construed as limiting the scope of the invention. The accompanying drawings are for reference and illustration only and do not constitute a limitation on the scope of protection of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention. In the description of the present invention, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise stated, "a plurality of" means two or more.

[0071] In the description of this invention, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to communication within two components. The terms "vertical," "horizontal," "left," "right," "upper," "lower," and similar expressions used herein are for illustrative purposes only and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0072] In the description of this invention, it should be noted that, unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing specific embodiments only and is not intended to limit the invention. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0073] Please see Figure 1 In an embodiment of the present invention, a converter current sharing control method is provided, the method being applied to a two-phase interleaved parallel Buck converter with a constant current source load, the method comprising:

[0074] S1. Based on the topology of the constant current source load two-phase interleaved parallel Buck converter and the rate of change of inductor current and output voltage of each phase of the topology, a first state-space model is constructed.

[0075] S2. Using the output voltage, the difference between the two-phase inductor currents, and the sum of the two-phase inductor currents as the first state variables of the state space model, the state space model is reconstructed to obtain the second state space model.

[0076] S3. Based on the linear relationship between the output voltage change rate and the sum of the two-phase inductor currents, and the linear relationship between the difference between the two-phase inductor currents and the output voltage, the second state space model is decoupled into an inductor current regulation subsystem and a voltage regulation subsystem by input transformation; the state variable of the inductor current regulation subsystem is the output voltage, and the state variable of the voltage regulation subsystem is a matrix composed of the output voltage and the sum of the two-phase inductor currents.

[0077] S4. Based on the inductor current regulation subsystem and the voltage regulation subsystem, construct the third state space model of the switching affine system.

[0078] S5. Based on the third state space model, construct the Lyapunov function of the switching affine system, and design the minimum projection controller according to the linear matrix inequality of the Lyapunov function.

[0079] S6. Based on the minimum projection controller, a control signal is generated using distributed minimum projection switch technology.

[0080] S7. The power switch is controlled by the control signal to adjust the output voltage of the Buck converter with two phases interleaved in parallel and to achieve current sharing control.

[0081] The constant current source load two-phase interleaved parallel Buck converter is a special power conversion device that combines the advantages of a constant current source load and a two-phase interleaved parallel Buck converter. This converter achieves step-down conversion of the input voltage while maintaining a constant output current by alternately switching two inductors. In the two-phase interleaved parallel Buck converter, the two inductors are connected to two switching transistors, which operate alternately to achieve alternating energy storage and release in the inductors. When one transistor is turned on, the corresponding inductor stores energy; when that transistor is turned off, the inductor releases the stored energy, and the stored current is output to the constant current source load through a diode. Because the two inductors operate alternately, higher conversion efficiency and lower output voltage ripple can be achieved.

[0082] like Figure 2 The diagram shows a schematic of a two-phase interleaved parallel Buck converter with a constant current source load, including: a voltage source E for providing the required input power supply voltage and a constant current source I for the output current. oSwitch S1 is connected in series with diode D1, and switch S2 is connected in series with diode D2. Switch S1 and diode D1 are then connected in parallel to voltage source E, and switch S2 and diode D2 are also connected in series and in parallel to voltage source E. Two energy storage inductors, L1 and L2, allow current to flow through diode D1 when switch S1 is off, and through diode D2 when switch S2 is off. The output capacitor C, connected in parallel to the constant current source load, maintains the stability of the constant current source load voltage as the switching states of switches S1 and S2 change.

[0083] For constant current source loads, two-phase interleaved parallel Buck converters need to maintain a constant and balanced output current. In a preferred embodiment of the present invention, to achieve a constant and balanced output current of the two-phase interleaved parallel Buck converter, firstly, a state variable is selected based on the topology of the two-phase interleaved parallel Buck converter for the constant current source load. This state variable is defined as a first state variable, which includes the first inductor current of the first phase converter, the second inductor current of the second phase converter, and the output voltage.

[0084] Based on the dynamic characteristics of the topology, a first state-space model of the topology is constructed. The first state-space model includes the first inductor current change rate equation, the second inductor current change rate equation, and the output voltage change rate equation. The first state-space model is shown below:

[0085]

[0086]

[0087]

[0088] Where i1(t) and i2(t) are the first and second inductor currents at time t, respectively, z3(t) is the output voltage at time t, E is the input voltage, and S1 and S2 are the control signals for the first and second switching transistors, respectively. Let be the rate of change of the first inductor current at time t. Let be the rate of change of the second inductor current at time t. Let I be the rate of change of the output voltage at time t. o L1 is the constant current source load current, C is the output capacitor, and L2 and L1 are the inductance values ​​of the first phase converter and the second phase converter, respectively.

[0089] Furthermore, the first state variables are transformed by introducing the difference between the two-phase inductor currents and the sum of the two-phase inductor currents to transform the first state variables of the first state space model. The first state variables are then transformed from the first inductor current of the first-phase converter, the second inductor current of the second-phase converter, and the output voltage to the output voltage, the difference between the two-phase inductor currents, and the sum of the two-phase inductor currents. The resulting second state space model is as follows:

[0090]

[0091]

[0092]

[0093] Where z1(t) represents the difference between the two-phase inductor currents of the first-phase converter and the second-phase converter at time t, z2(t) represents the sum of the two-phase inductor currents of the first-phase converter and the second-phase converter at time t, and S1(t) and S2(t) are the control signals of the first and second switching transistors at time t, respectively.

[0094] As shown in the second state-space model, the rate of change of voltage depends on the sum of the two-phase inductor currents, and the difference between the two-phase inductor currents depends on the output voltage. The second state-space model can be viewed as two interconnected systems. One subsystem controls the coupled dynamics of the output voltage and the sum of the two-phase inductor currents, representing a voltage regulation subsystem focused on voltage control. The other subsystem controls the coupled dynamics of the difference between the two-phase inductor currents and the output voltage, representing an inductor current regulation subsystem focused on inductor current control. The voltage regulation subsystem provides power to the inductor current regulation subsystem, and its dynamics are independent of the inductor current regulation subsystem. Therefore, based on the linear relationship between the rate of change of output voltage and the sum of the two-phase inductor currents, and the linear relationship between the difference between the two-phase inductor currents and the output voltage, the second state-space model is decoupled into an inductor current regulation subsystem and a voltage regulation subsystem using input transformation.

[0095] Furthermore, in the second state-space model, the voltage output and the sum of the two-phase inductor currents are transformed into a matrix composed of the output voltage and the sum of the two-phase inductor currents, thereby decoupling the two-phase inductor current difference from the voltage output and the sum of the two-phase inductor currents. Here, the input variable of the inductor current regulation subsystem is the output voltage, and the input variable of the voltage regulation subsystem is a matrix composed of the output voltage and the sum of the two-phase inductor currents. The voltage regulation subsystem cannot receive the reverse signal from the inductor current regulation subsystem.

[0096] The model equation for the inductor current regulation subsystem is as follows:

[0097]

[0098] The model equations for the voltage regulation subsystem are as follows:

[0099]

[0100] Based on switching affine theory, the inductor current regulation subsystem can be reconstructed as follows:

[0101]

[0102] in,

[0103] The voltage regulation subsystem is reconfigured as follows:

[0104]

[0105] in,

[0106] The reconstructed inductor current regulation subsystem and voltage regulation subsystem are used as the third state space model of the switching affine system.

[0107] Furthermore, based on the third state space model, the Lyapunov function of the switching affine system is constructed, and the minimum projection controller is designed according to the linear matrix inequality of the Lyapunov function.

[0108] The Lyapunov function is mainly used to determine the stability of nonlinear dynamic systems. When the Lyapunov function of a nonlinear dynamic system exists and satisfies positive definiteness and decreasing property, the stability of the system can be determined according to Lyapunov's stability theorem.

[0109] In a preferred embodiment of the present invention, a power switch control algorithm is designed based on the difference in current between the two-phase inductors and a preset reference output voltage. The power switch control algorithm is set to maximize the tracking of the reference output voltage and to ensure that the difference in current between the two-phase inductors is infinitely close to zero. The switch control algorithm is expressed as follows:

[0110]

[0111] Among them, v d This indicates the reference output voltage.

[0112] For the inductor current regulation subsystem, according to the power switch control algorithm, if the difference between the two-phase inductor currents z1(t) is 0, then the sum of the two-phase inductor currents z2(t) reaches the constant current source load current value, and the output voltage z3(t) stably tracks the reference output voltage. At this time, the equilibrium point of the switching affine system is reached. The equilibrium point of the switching affine system is expressed as:

[0113]

[0114] Among them, z1 e z2 e and z3 e These represent the values ​​of z1, z2, and z3 when the switching affine system reaches equilibrium, respectively.

[0115] Furthermore, the dynamic behavior of the switching affine system is averaged over time, and the switching state S1 is replaced by the average value. Switch state S2 is replaced with average value. Assuming the state variables of the switched affine system reach its equilibrium point, the set of switching equilibrium points under the current-sharing framework, with the two-phase inductor current difference approaching zero (i.e., i1 = i2), is determined by the algebraic conditions of the average system. The algebraic conditions of the average system are obtained by time averaging the dynamic behavior of the switched affine system, describing its stable behavior. The algebraic conditions of the average system are:

[0116]

[0117] Solving the algebraic conditions of the average system yields the set of switching equilibrium points:

[0118]

[0119] In a preferred embodiment of the present invention, the Lyapunov function is:

[0120]

[0121] in, z e =[z1 e z2 e z3 e ] T ,z e To switch the equilibrium point of the affine system, z1 e z2 e and z3 e These represent the values ​​of z1, z2, and z3 when the affine system reaches its equilibrium point. For the voltage regulation subsystem Σ v The equilibrium point, γ is the weighting factor for adjusting the flow sharing performance, and P is the positive definite matrix of the Lyapunov function.

[0122] In a preferred embodiment of the present invention, the stability of the switching affine system is ensured by ensuring the positive definiteness of the positive definite matrix.

[0123] Specifically, based on the equilibrium points and switching equilibrium point set of the switched affine system, the time rate of change equation of the switched affine system is constructed as follows:

[0124]

[0125] in, This represents the rate of change of time when switching affine systems.

[0126] Based on the time-rate-of-change equation, obtain the feedback gain matrix that controls the switching affine system to the equilibrium point. The feedback gain matrix reflects the switching balance relationship and is expressed as follows:

[0127] K = [K1, K2] T

[0128] Where K1 represents the feedback gain matrix of switch S1, and K2 represents the feedback gain matrix of switch S1.

[0129] The switching balance relationship and the feedback gain matrix have the following relationship:

[0130] [S1-S1 e S2-S2 e ] T =K(zz) e )

[0131] Furthermore, by differentiating the Lyapunov function along the trajectory of the switched affine system, we obtain:

[0132]

[0133] Furthermore, substituting the trajectory derivative into the equilibrium point of the switching affine system, we obtain the Lyapunov function index:

[0134]

[0135] The minimum projection controller is designed by selecting the Lyapunov function parameters related to switching transistor control. The minimum projection controller is:

[0136]

[0137]

[0138] in, S represents the combined control signals of the first switching transistor and the second transistor.

[0139] Furthermore, substituting the feedback gain matrix into the Lyapunov function index, we obtain:

[0140]

[0141] In order to facilitate subsequent quadratic inequality operations and better match the structure of system state variables and control inputs, the feedback gain matrix K is reasonably equivalent to:

[0142]

[0143]

[0144] Furthermore, the above The derivative along the trajectory of the switching affine system is transformed into a standard quadratic inequality, which is:

[0145]

[0146] in,

[0147] If Then the derivative of the Lyapunov function index along the trajectory of the switched affine system remains negative, thus ensuring the asymptotic stability of the switched affine system.

[0148] From the above standard quadratic form inequality, it can be seen that it does not satisfy the requirements of the linear matrix inequality. Therefore, by... Transforming the standard quadratic inequality, we get:

[0149]

[0150] in,

[0151] Furthermore, the weighting factors are determined through circuit simulation to make the positive definite matrix corresponding to the linear matrix inequality positive definite. The circuit simulation parameters are shown in Table 1.

[0152] Table 1

[0153] parameter value E 12V <![CDATA[L1]]> 300μH <![CDATA[L2]]> 200μH C 40μH <![CDATA[I o ]]> 3A

[0154] With a weighting factor of γ = 1.5, the circuit parameters in Table 1 are substituted into the constant current source load two-phase interleaved parallel Buck converter model. The linear matrix inequalities are solved using the LMI toolbox in MATLAB, yielding:

[0155]

[0156] P satisfies the positive definiteness requirement, thus maintaining the stability of the switching affine system.

[0157] Furthermore, based on the minimum projection controller, a distributed minimum projection switch technique is used to generate the control signal. With the objective of maximizing the decrease in the Lyapunov function index, the control signal of the minimum projection controller is solved. The control signal is:

[0158]

[0159] The first inductor current, second inductor current, input voltage, constant current source load current, and output capacitance of a two-phase interleaved parallel Buck converter with a constant current source load are collected, and the parameter z is calculated. e The values ​​of B1, B2, β1, and β2, combined with the weighting factors and positive definite matrices selected in the simulation, are used to obtain control signals. These signals control the on and off states of the switching transistors S1 and S2 of the two-phase interleaved parallel Buck converter with constant current source load, thereby adjusting the output voltage of the two-phase interleaved parallel Buck converter with constant current source load and achieving current sharing among the converters in each phase.

[0160] In this preferred embodiment, Figure 2 The simulation circuit diagram of the constant current source load two-phase interleaved parallel Buck converter on PSIM is shown below. Figure 3 As shown, a reference voltage V is selected. d =8V, output current I o =3A, the two-phase inductor current difference and output voltage waveforms after adopting the converter current sharing control method provided in this embodiment of the invention are as follows: Figure 4 and Figure 5 As shown; the difference in two-phase inductor current and output voltage when the input voltage jumps from 12V to 24V are respectively as follows: Figure 6 and Figure 7 As shown; the difference in inductor current and output voltage between the two phases when the reference voltage jumps from 8V to 5V are respectively as follows: Figure 8 and Figure 9 As shown, from Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 It is understood that the converter current sharing control method of the present invention can achieve precise current sharing control and fast voltage regulation, ensuring that the Buck converter with constant current source loads in two phases interleaved in parallel remains stable when the input voltage jumps or the reference voltage changes.

[0161] In a preferred embodiment of the present invention, a first state-space model is constructed based on the topology of a two-phase interleaved parallel Buck converter with a constant current source load and the rate of change of inductor current and output voltage of each phase of the topology. The difference between the two-phase inductor currents and the sum of the two-phase inductor currents are introduced to transform the state variables of the first state-space model, resulting in a second state-space model. Based on the linear relationship between the rate of change of output voltage and the sum of the two-phase inductor currents, and the linear relationship between the difference between the two-phase inductor currents and the output voltage, the second state-space model is decoupled into an inductor current regulation subsystem and a voltage regulation subsystem using input transformation. The state variable of the current regulation subsystem is the output voltage, and the state variable of the voltage regulation subsystem is a matrix composed of the output voltage and the sum of the two-phase inductor currents. Based on the inductor current regulation subsystem and the voltage regulation subsystem, a third state space model of the switching affine system is constructed. Based on the third state space model, the Lyapunov function of the switching affine system is constructed, and a minimum projection controller is designed according to the linear matrix inequality of the Lyapunov function. Based on the minimum projection controller, a distributed minimum projection switching technique is used to generate control signals. The control signals are used to control the power switches to regulate the output voltage and achieve current sharing control. The converter current sharing control method provided in this application can achieve precise current sharing control and fast voltage regulation, ensuring that the two-phase interleaved parallel Buck converter with constant current source load remains stable when the input voltage jumps or the reference voltage changes.

[0162] Accordingly, such as Figure 10 As shown, based on a converter current sharing control method, this embodiment of the invention also provides a converter current sharing control system. The system is applied to a two-phase interleaved parallel Buck converter with a constant current source load, and implements the converter current sharing control method disclosed in this embodiment of the invention. The system includes: a first state space model construction unit 1, a second state space model construction unit 2, an input transformation decoupling unit 3, a third state space construction unit 4, a minimum projection controller design unit 5, a control signal generation unit 6, and a current sharing control unit 7.

[0163] The first state space model construction unit 1 is used to construct a first state space model based on the topology of the constant current source load two-phase interleaved parallel Buck converter and the rate of change of inductor current and output voltage of each phase of the topology.

[0164] The second state space model construction unit 2 is used to introduce the difference between two-phase inductor currents and the sum of the two-phase inductor currents to transform the state variables of the first state space model to obtain the second state space model.

[0165] The input transformation decoupling unit 3 is used to decouple the second state space model into an inductor current regulation subsystem and a voltage regulation subsystem based on the linear relationship between the output voltage change rate and the sum of the two-phase inductor currents, and the linear relationship between the difference between the two-phase inductor currents and the output voltage. The state variable of the inductor current regulation subsystem is the output voltage, and the state variable of the voltage regulation subsystem is a matrix composed of the output voltage and the sum of the two-phase inductor currents.

[0166] The third state space construction unit 4 is used to construct a third state space model of the switching affine system based on the inductor current regulation subsystem and the voltage regulation subsystem.

[0167] The minimum projection controller design unit 5 is used to construct the Lyapunov function of the switching affine system based on the third state space model, and to design the minimum projection controller according to the linear matrix inequality of the Lyapunov function.

[0168] The control signal generation unit 6 is used to generate control signals based on the minimum projection controller using distributed minimum projection switching technology.

[0169] The current sharing control unit 7 is used to control the power switch with the control signal to adjust the output voltage and achieve current sharing control.

[0170] For specific limitations regarding a converter current sharing control system, please refer to the above-described limitations regarding a converter current sharing control method, which will not be repeated here. Those skilled in the art will recognize that the modules and steps described in conjunction with the embodiments disclosed in this invention can be implemented in hardware, software, or a combination of both. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this invention.

[0171] like Figure 11 As shown, an embodiment of the present invention provides a computer device including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the steps described in the above embodiment of the converter current sharing control method, for example... Figure 1 Steps S1 to S7 as described above.

[0172] Those skilled in the art will understand that the illustrations Figure 11This is merely an example of a computer device and does not constitute a limitation on the computer device. It may include more or fewer components than shown, or combine certain components, or different components. For example, the computer device may also include input / output devices, network access devices, buses, etc.

[0173] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the computer device, connecting various parts of the computer device via various interfaces and lines.

[0174] The memory can be used to store the computer programs and / or modules. The processor implements various functions of the computer device by running or executing the computer programs and / or modules stored in the memory and by calling data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the mobile phone (such as audio data, phonebook, etc.). In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0175] If the modules integrated into the computer device are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0176] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0177] Accordingly, embodiments of the present invention provide a computer-readable storage medium, the computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to perform steps in the converter current sharing control method of the above embodiments, for example... Figure 1 Steps S1 to S7 as described above.

[0178] This embodiment provides a converter current sharing control method, system, device, and medium to solve the technical problem of improving the accuracy and flexibility of current sharing control while achieving output voltage regulation. Based on the topology of a two-phase interleaved parallel Buck converter with a constant current source load and the rate of change of inductor current and output voltage in each phase of the topology, a first state-space model is constructed. The difference between the two-phase inductor currents and the sum of the two-phase inductor currents are introduced to transform the state variables of the first state-space model, resulting in a second state-space model. Based on the linear relationship between the output voltage change rate and the sum of the two-phase inductor currents, and the linear relationship between the difference between the two-phase inductor currents and the output voltage, the second state-space model is decoupled into an inductor current regulation subsystem and a voltage regulation subsystem using input transformation. The input variable of the system is the output voltage, and the input variable of the voltage regulation subsystem is a matrix composed of the output voltage and the sum of the two-phase inductor currents. Based on the inductor current regulation subsystem and the voltage regulation subsystem, a third state space model of the switching affine system is constructed. Based on the third state space model, the Lyapunov function of the switching affine system is constructed, and a minimum projection controller is designed according to the linear matrix inequality of the Lyapunov function. Based on the minimum projection controller, a distributed minimum projection switching technique is used to generate control signals. The control signals are used to control the power switches to regulate the output voltage and achieve current sharing control. The converter current sharing control method provided in this application can achieve accurate current sharing control and fast voltage regulation, ensuring that the two-phase interleaved parallel Buck converter with constant current source load remains stable when the input voltage jumps or the reference voltage changes.

[0179] The embodiments in this specification are described in a progressive manner. For directly identical or similar parts among the embodiments, refer to each other. Each embodiment focuses on its differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. It should be noted that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as these combinations of technical features do not contradict each other, they should be considered within the scope of this specification.

[0180] The above-described embodiments are merely preferred embodiments of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various improvements and substitutions without departing from the principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A converter current sharing control method, characterized in that, The method is applied to a two-phase interleaved parallel Buck converter with a constant current source load, and the method includes: Based on the topology of the constant current source load two-phase interleaved parallel Buck converter and the rate of change of inductor current and output voltage of each phase of the topology, a first state-space model is constructed. The state variables of the first state space model are transformed by introducing the difference between the two-phase inductor currents and the sum of the two-phase inductor currents to obtain the second state space model. Based on the linear relationship between the output voltage change rate and the sum of the two-phase inductor currents, and the linear relationship between the difference between the two-phase inductor currents and the output voltage, the second state-space model is decoupled into an inductor current regulation subsystem and a voltage regulation subsystem using input transformation; the state variable of the inductor current regulation subsystem is the output voltage, and the state variable of the voltage regulation subsystem is a matrix composed of the output voltage and the sum of the two-phase inductor currents; Based on the inductor current regulation subsystem and the voltage regulation subsystem, a third state space model of the switching affine system is constructed. Based on the third state space model, the Lyapunov function of the switching affine system is constructed, and the minimum projection controller is designed according to the linear matrix inequality of the Lyapunov function. Based on the aforementioned minimum projection controller, a distributed minimum projection switch technique is used to generate control signals; The power switch is controlled by the control signal to adjust the output voltage and achieve current sharing control.

2. The converter current sharing control method as described in claim 1, characterized in that, The first state-space model is constructed based on the topology of the two-phase interleaved parallel Buck converter with the constant current source load and the rate of change of inductor current and output voltage of each phase of the topology, including: Based on the topology of the constant current source load two-phase interleaved parallel Buck converter, the first state variable of the constant current source load two-phase interleaved parallel Buck converter is selected. The first state variable includes the first inductor current of the first phase converter, the second inductor current of the second phase converter, and the output voltage. Based on the first state variable, a first state space model of the topology is constructed. The first state space model includes a first inductor current rate of change equation, a second inductor current rate of change equation, and an output voltage rate of change equation.

3. The converter current sharing control method as described in claim 1, characterized in that, Based on the linear relationship between the output voltage change rate and the sum of the two-phase inductor currents, and the linear relationship between the difference between the two-phase inductor currents and the output voltage, the second state-space model is decoupled into an inductor current regulation subsystem and a voltage regulation subsystem using input transformation, including: In the second state space model, the voltage output and the sum of the two-phase inductor currents are changed into a matrix composed of the output voltage and the sum of the two-phase inductor currents, so as to decouple the second state space model into an inductor current regulation subsystem and a voltage regulation subsystem. The voltage regulation subsystem cannot receive the reverse signal of the inductor current regulation subsystem. The model equation for the inductor current regulation subsystem is: The model equation for the voltage regulation subsystem is: in, express The difference in two-phase inductor current between the first-phase converter and the second-phase converter at any given moment. express The sum of the two-phase inductor currents of the first-phase converter and the second-phase converter at that moment. for Output voltage at all times Input voltage, and They are respectively The control signals for the first and second switching transistors at specific times. For constant current source load current, For output capacitor, and These are the inductance values ​​of the first-phase converter and the second-phase converter, respectively.

4. The converter current sharing control method as described in claim 3, characterized in that, The Lyapunov function for constructing the switched affine system based on the third state space model includes: Based on the current difference between the two-phase inductors and the preset reference output voltage, a power switch control algorithm is designed. The power switch control algorithm is set to ensure that the output voltage tracks the reference output voltage to the maximum extent and that the current difference between the two-phase inductors approaches zero infinitely. Based on the power switch control algorithm, the balance point of the switching affine system is obtained, and the set of switch balance points is obtained based on the balance point of the switching affine system. Based on the third state space model and the set of switch equilibrium points, the Lyapunov function of the switching affine system is constructed.

5. The converter current sharing control method as described in claim 4, characterized in that, The Lyapunov function is: in, , , , To switch the balance point of the affine system, , and They represent , and The value at which the affine system reaches equilibrium after switching. For voltage regulation subsystem The equilibrium point To adjust the weighting factor for flow sharing performance, Let be the positive definite matrix of the Lyapunov function.

6. The converter current sharing control method as described in claim 5, characterized in that, The design of the minimum projection controller based on the linear matrix inequality of the Lyapunov function includes: The Lyapunov function is differentiated along the trajectory of the switched affine system, and the Lyapunov function index is obtained by substituting the equilibrium point of the switched affine system into the derivative. A minimum projection controller is designed by selecting the portion of the Lyapunov function index related to switching transistor control. The minimum projection controller is as follows: in, , , , This represents the combined control signal set for the first and second switching transistors. Based on the equilibrium point of the switching affine system and the set of switching equilibrium points, construct the time rate of change equation of the switching affine system; Based on the time rate of change equation, obtain the feedback gain matrix that controls the switching affine system to the equilibrium point. The feedback gain matrix is ​​used to reflect the switching balance relationship. Substitute the feedback gain matrix into the Lyapunov function index, and transform the derivative along the trajectory of the switched affine system into a standard quadratic inequality; The standard quadratic inequality is converted into a linear matrix inequality. The weighting factor is selected through circuit simulation, and the linear matrix inequality is solved to obtain a positive definite matrix that meets the positive definiteness requirement.

7. The converter current sharing control method as described in claim 6, characterized in that, Based on the aforementioned minimum projection controller, a distributed minimum projection switch technique is used to generate control signals, including: The control signal of the minimum projection controller is solved with the objective of maximizing the decrease of the Lyapunov function index. The control signal is: 。 8. A converter current sharing control system, implementing the converter current sharing control method according to any one of claims 1-7, characterized in that, The system is applied to a two-phase interleaved parallel Buck converter with a constant current source load. The system includes: a first state space model construction unit, a second state space model construction unit, an input transformation decoupling unit, a third state space model construction unit, a minimum projection controller design unit, a control signal generation unit, and a current sharing control unit. The first state-space model construction unit is used to construct a first state-space model based on the topology of the constant current source load two-phase interleaved parallel Buck converter and the rate of change of inductor current and output voltage of each phase of the topology. The second state space model construction unit is used to introduce the difference between two-phase inductor currents and the sum of the two-phase inductor currents to transform the state variables of the first state space model to obtain the second state space model. The input transformation decoupling unit is used to decouple the second state-space model into an inductor current regulation subsystem and a voltage regulation subsystem based on the linear relationship between the output voltage change rate and the sum of the two-phase inductor currents, and the linear relationship between the difference between the two-phase inductor currents and the output voltage. The input variable of the inductor current regulation subsystem is the output voltage, and the input variable of the voltage regulation subsystem is a matrix composed of the output voltage and the sum of the two-phase inductor currents. The third state space model construction unit is used to construct a third state space model of the switching affine system based on the inductor current regulation subsystem and the voltage regulation subsystem. The minimum projection controller design unit is used to construct the Lyapunov function of the switching affine system based on the third state space model, and to design the minimum projection controller according to the linear matrix inequality of the Lyapunov function. The control signal generation unit is used to generate control signals based on the minimum projection controller using distributed minimum projection switching technology; The current sharing control unit is used to control the power switch using the control signal to adjust the output voltage and achieve current sharing control.

9. A computer device, characterized in that: The computer device includes a memory, a processor, and a transceiver, which are connected to each other via a bus; the memory is used to store a set of computer program instructions and data, and to transmit the stored data to the processor, and the processor executes the program instructions stored in the memory to perform the converter current sharing control method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program that, when executed, implements the converter current sharing control method as described in any one of claims 1 to 7.

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