A model predictive control method for a multi-path switching buck-boost converter

Abstract

The application discloses a model prediction control method of a multi-path switching Buck-Boost converter and relates to power electronic conversion control. The technical solution points are as follows: step 1: output voltage and current detection and preprocessing; step 2: voltage outer loop PI regulation and current reference value generation; step 3: current inner loop mode division model prediction control; step 4: double-state observer design and parameter estimation; and step 5: power supply switching logic and PWM signal generation. The application mainly detects input power supply voltage and load state, adaptively matches optimal working modes and control parameters, ensures synchronous and accurate control in all power supply switching and mode conversion processes, realizes smooth action of main switching devices and output voltage stability through one set of control architecture, and significantly improves system efficiency and robustness.

Description

Technical Field

[0001] This invention relates to the field of power electronic conversion control technology, and in particular to a model predictive control method for a multi-channel switching Buck-Boost converter. Background Technology

[0002] With the widespread application of power electronics technology in communication base stations, photovoltaic energy storage, industrial control, and aerospace, critical loads are facing increasingly stringent requirements for power supply reliability and voltage stability. Multi-source auxiliary power supply solutions, due to their ability to improve power supply continuity, have become a key technical means to ensure the stable operation of sensitive loads. As the core energy conversion unit of a multi-source system, the Buck-Boost converter needs to achieve flexible switching between power sources and precise control of the output voltage.

[0003] Traditional multi-channel switching Buck-Boost converter control schemes mostly employ a proportional-integral (PI) dual-loop strategy, but they have significant technical drawbacks: First, dynamic response lag. Under nonlinear conditions such as power switching and load abrupt changes, PI control relying on a small-signal linearization model is prone to large output voltage overshoot and long settling time, failing to meet the stringent voltage fluctuation requirements of sensitive loads such as radar and spaceborne computers. Second, parameter sampling is limited. Inductor current, as the core control variable, needs to be detected in real time through sampling resistors or current sensors, which is greatly affected by electromagnetic interference and sampling accuracy, and it is difficult to deploy sampling elements in highly integrated scenarios. Third, poor load adaptability. When the load impedance changes dynamically, the controller with fixed parameters cannot adjust the control strategy in real time, leading to a decrease in system robustness. Fourth, unsmooth mode switching. Traditional dual-mode (Buck / Boost) control has a voltage gain dead zone when the input and output voltages are similar, which can easily cause mode switching oscillations and affect power supply stability.

[0004] Model predictive control (MPC), as a novel nonlinear control method, boasts advantages such as fast dynamic response and strong multi-objective control capabilities. However, existing MPC solutions are not optimized for multi-channel switching scenarios: they lack integration with power supply priority switching logic, leading to significant voltage fluctuations during switching; and they fail to address the challenges of sampling inductor current and time-varying load impedance, limiting their engineering applications. Therefore, a novel control strategy that adapts to multi-channel switching scenarios and balances control accuracy and robustness is urgently needed. Summary of the Invention

[0005] To address the above shortcomings, this invention provides a model predictive control method for a multi-channel switching Buck-Boost converter. By establishing a predictive model in different modes, introducing a dual-state observer, and designing power priority switching logic, it can achieve rapid dynamic response, low voltage fluctuation, and precise control without sampling dependence under multiple power supply switching and load change conditions, and adapt to stable power supply under any power demand.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A model predictive control method for a multi-channel switched Buck-Boost converter includes the following steps: Step 1: Output voltage and current detection and preprocessing; Step 2: Voltage outer loop PI adjustment and current reference value generation; Step 3: Current inner loop sub-mode model predictive control; Step 4: Design and parameter estimation of the two-state observer; Step 5: Power switching logic and PWM signal generation.

[0007] Furthermore, step 1 includes the following sub-steps: Step 1.1: Acquire the five input power supply voltage signals and output voltage signals using a voltage sampler; Step 1.2: Acquire the output current signal using a current sampler, and calculate the initial load impedance value by combining it with the output voltage; Step 1.3: Input the five input power voltage signals into the power priority detection module, determine the current working power supply in the order of "Vin1→Vin2→Vin3→Vin4→Vin5→Vin1", and output the working power supply voltage and power status signal. Step 1.4: Compare the operating power supply voltage Vin with the output voltage reference value V. ref The input mode determination module outputs the converter operating mode signal mode. The operating mode signals are: mode=1 corresponds to Buck mode, mode=2 corresponds to Boost mode, and mode=3 corresponds to transition mode.

[0008] Furthermore, a power status signal of 1 indicates that the power supply is normal; a power status signal of 0 indicates that the power supply is faulty.

[0009] Furthermore, a converter operating mode signal of 1 indicates Buck mode; a converter operating mode signal of 2 indicates Boost mode; and a converter operating mode signal of 3 indicates transition mode.

[0010] Furthermore, step 2 includes the following sub-steps: Step 2.1: Subtract the output voltage reference value from the sampled value to obtain the voltage error signal; Step 2.2: Input the voltage error signal into the PI controller to generate the inductor current reference value. The discrete domain transfer function of the PI controller is: in, For proportional gain, Let Z be the integral gain, T be the control period, and Z be the complex variable. Step 2.3: Based on the converter operating mode signal, adaptively adjust the PI regulator parameters to ensure that the voltage loop bandwidth matches the switching frequency in different modes.

[0011] Furthermore, step 3 includes the following sub-steps: Step 3.1: Establish the state equations for the corresponding mode: Buck mode: Boost Mode: Transition mode: Step 3.2: Discretize the state equations using the forward Euler method to establish a prediction model for inductor current and output voltage: in, Let f(.) be the duty cycle of the current switching cycle, and f(.) be the mode-dependent state function. Step 3.3: Construct a cost function that includes control objectives and constraints: Where P and Q are weighting coefficients, both taken as 0.5. This is the duty cycle constraint penalty term, and d(k)∈[0,1]; Step 3.4: Solve the optimal control law corresponding to the minimum cost function offline to obtain the optimal duty cycle d*(k) for the current cycle.

[0012] Furthermore, step 4 includes the following sub-steps: Step 4.1: Design an inductor current observer to achieve sampling-free estimation of the inductor current based on the output voltage and duty cycle. The observation equation is: in, This is the observed value of the inductor current; For the output voltage observation value, , For observer gain, and , ; Step 4.2: Design the load impedance observer and define... Establish observation equations to track load changes in real time: in, for The observed values, , For observer gain; Step 4.3: The observed data... and Substitute the values ​​into the model predictive control calculations to replace the actual sampled values, thereby improving control robustness.

[0013] Furthermore, step 5 includes the following sub-steps: Step 5.1: Monitor the working power status signal in real time. When the working power status signal = 0, it is determined that the current power supply is faulty. Start the power switching program and switch to the next priority power supply within 0.3ms. Update the working power supply voltage and working mode signal. Step 5.2: Based on the optimal duty cycle d*(k) and the power switching state, generate the main switch PWM drive signal, and control the switching on and off of the switch after amplification by the drive circuit; Step 5.3: During the power switching transition period, start the smooth switching algorithm of the startup mode and call the optimal control law of the corresponding mode to ensure that the output voltage is oscillating.

[0014] Compared with the prior art, the beneficial effects of the present invention are that the model predictive control strategy realizes adaptive control in multi-power switching scenarios through mode-specific predictive modeling and dual-state observer design. Only one control architecture is needed to complete the precise driving and power switching management of all main switching devices. All main switching transistors are controlled smoothly, and all power switching processes maintain low voltage fluctuations, which significantly reduces system losses and control complexity, and improves the stability and reliability of the converter under wide input voltage and wide load range. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0016] Figure 1 This is an example topology diagram of the model predictive control method for a multi-channel switched Buck-Boost converter according to the present invention; Figure 2 This is a flowchart illustrating the model predictive control method for a multi-channel switched Buck-Boost converter according to the present invention. Figure 3 This is a comparison diagram of the architectures of traditional PI dual-loop control and the model predictive control strategy of this invention; Figure 4 This is an implementation logic diagram of the model predictive control method for a multi-channel switched Buck-Boost converter according to the present invention; Figure 5The theoretical waveform diagram is shown for the model predictive control method of a multi-channel switched Buck-Boost converter according to the present invention. Figure 6 The equivalent circuit diagram of the Buck mode operation of the model predictive control method for a multi-channel switched Buck-Boost converter according to the present invention is shown below. Figure 7 The circuit diagram for Boost mode operation of the model predictive control method for a multi-channel switched Buck-Boost converter according to the present invention is shown below. Figure 8 The equivalent circuit diagram for the transition mode operation of the model predictive control method for a multi-channel switched Buck-Boost converter according to the present invention is shown below. Figure 9 This is a waveform diagram of the power switching process of a model predictive control method for a multi-channel switched Buck-Boost converter according to the present invention. Figure 10 Comparison of inductor current observation waveforms for a model predictive control method for a multi-channel switched Buck-Boost converter according to the present invention; Figure 11 The load change response waveform diagram is shown for the model predictive control method of a multi-channel switched Buck-Boost converter according to the present invention. Figure 12 The single-mode steady-state experimental waveform diagram is shown for the model predictive control method of a multi-channel switched Buck-Boost converter according to the present invention. Figure 13 The experimental waveform diagram for multi-mode switching of the model predictive control method for a multi-channel switched Buck-Boost converter of the present invention is shown below. Figure 14 The power switching experimental waveform diagram is shown for the model predictive control method of a multi-channel switching Buck-Boost converter according to the present invention. Figure 15 The waveform diagram is an experimental verification diagram of the state observer for the model predictive control method of a multi-channel switched Buck-Boost converter of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0020] Figure 1 This is a multi-channel switching Buck-Boost converter topology. The circuit includes five independent power supplies, an input-side main control switch group, and a dual-transistor anti-series connection to prevent shoot-through and protect the power supply. The input-side synchronous rectifier switch and output-side components are multiplexed to simplify the circuit and reduce cost. The circuit includes a power inductor L, an output capacitor C0, a load R, a driver circuit module, a sampling circuit module, and a control chip module. The power inductor L stores and releases energy, while the output capacitor C0 stabilizes the output voltage.

[0021] The five independent power supplies include a first independent DC power supply V1, a second independent DC power supply V2, a third independent DC power supply V3, a fourth independent DC power supply V4, and a fifth independent power supply V5.

[0022] The input-side main control switch group includes a first reverse series switch, a second reverse series switch, a third reverse series switch, a fourth reverse series switch, and a fifth reverse series switch, with each of the reverse series switches corresponding to one power input.

[0023] The first reverse series switch includes a first switch S1 and a second switch S2; the second reverse series switch includes a third switch S1 and a fourth switch S2; the third reverse series switch includes a fifth switch, an output-side main control switch S5, and a sixth switch S6; the fourth reverse series switch includes a seventh switch S7 and an eighth switch S8; and the fifth reverse series switch includes a ninth switch S9 and a tenth switch S10.

[0024] The key features of the multi-channel switching Buck-Boost converter lie in its adaptive switching of multiple power supplies and multi-mode collaborative control capabilities. Current inner-loop model predictive control provides precise duty cycle adjustment for the converter's three operating modes (Buck mode, Boost mode, and transient mode), ensuring stable output voltage. Dual-state observers enable inductor current estimation without sampling and real-time load impedance tracking, respectively, solving parameter sampling challenges and addressing time-varying load interference. Power supply priority switching logic ensures rapid switching to backup power in case of main power supply failure, improving power supply continuity. To simplify the analysis, the following assumptions are made: all power devices operate under ideal conditions; the output capacitor is large enough to minimize output voltage fluctuations; the power inductor current is continuous, and the load inductance is much larger than the parasitic inductance, making the load current approximately a constant current source during the switching cycle.

[0025] For a multi-channel switching Buck-Boost converter, the input voltage is higher than the output voltage, which is called Buck mode; the input voltage is lower than the output voltage, which is called Boost mode; and the input voltage is close to the output voltage (23V≤Vin≤25V), which is called transition mode. The converter operates in two core scenarios: single-supply steady-state operation and multi-supply switching.

[0026] Figure 2 The diagram illustrates the operating mode transitions in two scenarios. The steady-state operating scenario corresponds to continuous operation in a single mode, while the power switching scenario represents the dynamic mode transition process as the power supply voltage changes. Mode 1 represents Buck mode steady-state operation (Vin > 25V), Mode 2 represents Boost mode steady-state operation (Vin < 23V), Mode 3 represents transition mode steady-state operation (23V ≤ Vin ≤ 25V), and Mode 4 represents the mode transition process triggered by power switching.

[0027] A model predictive control method for a multi-channel switched Buck-Boost converter includes the following steps: Step 1: Output voltage and current detection and preprocessing.

[0028] Step 1.1: Acquire the voltage signals and output voltage signal Vo of five independent power supplies using a voltage sampler; the five independent power supply voltage signals include the voltage signal Vin1 of the first independent DC power supply V1, the voltage signal Vin2 of the second independent DC power supply V2, the voltage signal Vin3 of the third independent DC power supply V3, the voltage signal Vin4 of the fourth independent DC power supply V4, and the voltage signal Vin5 of the fifth independent power supply V5; where Vin1~Vin5 are the real-time voltage values ​​of the five independent power supplies, and Vo is the voltage at the converter output terminal.

[0029] Step 1.2: Acquire the output current signal Io using a current sampler, and calculate the initial load impedance value R by combining it with the output voltage Vo.

[0030] Step 1.3: Input the five input power voltage signals into the power priority detection module, and determine the current working power supply in the order of "Vin1→Vin2→Vin3→Vin4→Vin5→Vin1". Output the working power supply voltage Vin and the power status signal Vin. Power status signal: Vin=1 indicates that the power supply is normal, and Vin=0 indicates that the power supply is faulty.

[0031] Step 1.4: Input the operating power supply voltage Vin and the output voltage reference value Vref into the mode determination module, and output the converter operating mode signal mode. The operating mode signals are: mode=1 corresponds to Buck mode, mode=2 corresponds to Boost mode, and mode=3 corresponds to transition mode.

[0032] Step 2: Voltage outer loop PI adjustment and current reference value generation.

[0033] Step 2.1: Set the output voltage reference value V ref With sampled value V O By subtracting the values, we obtain the voltage error signal V. ref -V o .

[0034] Step 2.2: Input the voltage error signal into the PI regulator to generate the inductor current reference value I. ref The discrete-domain transfer function of the PI controller is: in, For proportional gain, Let Z be the integral gain, T be the control period, and Z be the complex variable.

[0035] Step 2.3: Based on the working mode signal mode, adaptively adjust the PI regulator parameters to ensure that the voltage loop bandwidth matches the switching frequency in different modes (when the switching frequency is 50kHz, the bandwidth is 1~2.5kHz).

[0036] Step 3: Current inner loop sub-mode model predictive control.

[0037] Step 3.1: Establish the state equations for the corresponding mode: Buck mode: Boost Mode: Transition mode: Step 3.2: Discretize the state equations using the forward Euler method to establish a prediction model for inductor current and output voltage: in, f(.) represents the duty cycle of the current switching cycle, and f(.) is the mode-dependent state function.

[0038] Step 3.3: Construct a cost function that includes control objectives and constraints: Where P and Q are weighting coefficients, both taken as 0.5. This is the duty cycle constraint penalty term, and d(k)∈[0,1].

[0039] Step 3.4: Solve the optimal control law corresponding to the minimum cost function offline to obtain the optimal duty cycle d*(k) for the current cycle.

[0040] Step 4: Design and parameter estimation of the dual-state observer.

[0041] Step 4.1: Design an inductor current observer to achieve sampling-free estimation of the inductor current based on the output voltage and duty cycle. The observation equation is: in, This is the observed value of the inductor current; For the output voltage observation value, , For observer gain, and , .

[0042] Step 4.2: Design the load impedance observer and define... Establish observation equations to track load changes in real time: in, for The observed values, , This is the observer gain.

[0043] Step 4.3: The observed data... and Substitute the values ​​into the model predictive control calculations to replace the actual sampled values, thereby improving control robustness.

[0044] Step 5: Power switching logic and PWM (Pulse Width Modulation) signal generation.

[0045] Step 5.1: Real-time monitoring of the power supply status signal V in When V in When the value is 0, it indicates a current power supply failure. The power switching procedure is initiated, and the system switches to the next priority power supply within 0.3ms, updating the operating power supply voltage V. in The operating mode signal, mode.

[0046] Step 5.2: Based on the optimal duty cycle d*(k) and the power switching state, generate the PWM drive signal for the main control switch group on the input side, and control the switching transistors to turn on and off after amplification by the drive circuit.

[0047] Step 5.3: During the power switching transition period, start the smooth switching algorithm of the startup mode and call the optimal control law of the corresponding mode to ensure that the output voltage is oscillating.

[0048] Example: Figure 3 This is a comparison diagram of the architecture of traditional PI dual-loop control and the model predictive control strategy of the present invention, where (a) is the architecture diagram of traditional PI dual-loop control and (b) is the architecture diagram of the model predictive control strategy of the present invention. Figure 4 This is an implementation logic diagram of the model predictive control method for a multi-channel switched Buck-Boost converter according to the present invention.

[0049] The waveforms at key points of converter operation are as follows: Figure 5 As shown, the typical working mode is as follows: Figures 6-8 As shown. The following section analyzes the various operating modes of the circuit. Taking the mode switching process triggered by power switching as an example, the entire control process can be divided into six stages.

[0050] Phase 1 (t0~t1): such as Figure 6 As shown, in the initial state, the converter is powered by power supply 1, which has a voltage of 27V and operates in Buck mode. The switching states are as follows: the sixth switch S6 is switched on and off according to the optimal duty cycle; the seventh switch S7 is normally closed; and the eighth and ninth switches S8 and S9 are complementaryly turned on. The load current forms a loop through the sixth switch S6 and the ninth switch S9. The auxiliary circuit is not activated, and the output voltage is stable at 24V.

[0051] Phase 2 (t1~t2): At time t1, the voltage of power supply 1 drops out of its operating range (18~30V), the power supply status signal is 0, the power supply switching program is initiated, and power is switched to power supply 2. The voltage of power supply 2 is 20V, and the operating mode is switched to Boost mode. At the same time, the inductor current observer and the load impedance observer are activated, quickly tracking the actual values ​​of the inductor current and load impedance, and the observation error gradually converges to 0.

[0052] Phase 3 (t2~t3): such as Figure 7 As shown, at time t2, the control strategy switches to the Boost mode optimal control law. The seventh switch S7 turns on and off according to the new optimal duty cycle, while the sixth switch S6 remains normally open, adjusting the switching timing to match the new power supply voltage. The auxiliary inductor L begins to charge and discharge according to the Boost mode characteristics, with the inductor current increasing at a slope of Vin / L, and the output voltage remaining stable.

[0053] Phase 4 (t3~t4): At time t3, the load impedance changes abruptly, rising from 4.8Ω to 9.6Ω. The load impedance observer quickly detects the impedance change and feeds the observed value back to the model predictive controller. The controller adjusts the cost function parameters and the optimal duty cycle in real time to suppress output voltage fluctuations.

[0054] Phase 5: (t4~t5): such as Figure 8 As shown, at time t4, the voltage of power supply 2 becomes abnormal, and power is switched to power supply 3, which has a voltage of 24V. The operating mode is changed to transition mode. The duty cycle of the sixth switch S6 is fixed at 0.85, and the duty cycle of the seventh switch S7 is adjusted to stabilize the voltage. At this time, the inductor current changes in three stages to ensure that there is no oscillation during the mode transition.

[0055] Phase 6 (t5~t6): At time t5, the power supply switching and mode conversion are completed, the converter enters the transition mode steady-state operation, the output voltage stabilizes at 24V, the observed value of the inductor current is basically consistent with the actual value, the observed value of the load impedance is accurately tracked, and the system enters a stable working state.

[0056] To verify the above theoretical analysis, a simulation model was constructed. The parameters of the multi-channel switching Buck-Boost converter used in the simulation are shown in Table 1. Figure 9 The output voltage and inductor current waveforms during the power switching process are shown. As can be seen from the figure, the output voltage fluctuation is ≤0.3V and the dynamic response time is ≤0.4ms during power switching, with no obvious oscillation. Figure 10 For the comparison of inductor current observation waveforms, the error between the observed value and the actual value is ≤1%, achieving high-precision sampling-free estimation. Figure 11 The waveform represents the response to a sudden load change. When the load impedance changes abruptly, the voltage fluctuation is ≤0.13V and the settling time is ≤0.34ms, indicating excellent system robustness.

[0057] To further verify the feasibility of the control strategy, a 120W multi-channel switching Buck-Boost converter prototype was manufactured. Figures 12-14 The experimental waveforms for single-mode steady-state, multi-mode switching, and power switching are displayed. From... Figure 12 As can be seen, in Buck mode, the output voltage is stable at 24V, the average inductor current is 5A, and the ripple meets the design requirements. Figure 13 The output voltage does not fluctuate significantly during the display mode switching process, achieving a smooth transition; Figure 14 This indicates that the dynamic response is fast during power switching and the voltage fluctuation is smaller than that of the traditional PI control scheme, verifying the superiority of the control strategy of the present invention. Figure 15 The waveform diagram shows the experimental verification of the state observer.

[0058] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included 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 model predictive control method for a multi-channel switched Buck-Boost converter, characterized in that, Includes the following steps: Step 1: Output voltage and current detection and preprocessing; Step 2: Voltage outer loop PI adjustment and current reference value generation; Step 3: Current inner loop sub-mode model predictive control; Step 4: Design and parameter estimation of the two-state observer; Step 5: Power switching logic and PWM signal generation.

2. The model predictive control method for a multi-channel switched Buck-Boost converter according to claim 1, characterized in that, Step 1 includes the following sub-steps: Step 1.1: Acquire the five input power supply voltage signals and output voltage signals using a voltage sampler; Step 1.2: Acquire the output current signal using a current sampler, and calculate the initial load impedance value by combining it with the output voltage; Step 1.3: Input the five input power voltage signals into the power priority detection module, determine the current working power supply in the order of "Vin1→Vin2→Vin3→Vin4→Vin5→Vin1", and output the working power supply voltage and power status signal. Step 1.4: Compare the operating power supply voltage Vin with the output voltage reference value V. ref The input mode determination module outputs the converter operating mode signal "mode".

3. The model predictive control method for a multi-channel switched Buck-Boost converter according to claim 2, characterized in that, A power status signal of 1 indicates that the power supply is normal; a power status signal of 0 indicates that the power supply is faulty.

4. The model predictive control method for a multi-channel switched Buck-Boost converter according to claim 3, characterized in that, A converter operating mode signal of 1 indicates Buck mode; a converter operating mode signal of 2 indicates Boost mode; and a converter operating mode signal of 3 indicates transition mode.

5. The model predictive control method for a multi-channel switched Buck-Boost converter according to claim 1, characterized in that, Step 2 includes the following sub-steps: Step 2.1: Subtract the output voltage reference value from the sampled value to obtain the voltage error signal; Step 2.2: Input the voltage error signal into the PI controller to generate the inductor current reference value. The discrete domain transfer function of the PI controller is: in, For proportional gain, Let Z be the integral gain, T be the control period, and Z be the complex variable. Step 2.3: Based on the converter operating mode signal, adaptively adjust the PI regulator parameters to ensure that the voltage loop bandwidth matches the switching frequency in different modes.

6. The model predictive control method for a multi-channel switched Buck-Boost converter according to claim 1, characterized in that, Step 3 includes the following sub-steps: Step 3.1: Establish the state equations for the corresponding mode: Buck mode: Boost Mode: Transition mode: Step 3.2: Discretize the state equations using the forward Euler method to establish a prediction model for inductor current and output voltage: in, Let f(.) be the duty cycle of the current switching cycle, and f(.) be the mode-dependent state function. Step 3.3: Construct a cost function that includes control objectives and constraints: Where P and Q are weighting coefficients, both taken as 0.

5. This is the duty cycle constraint penalty term, and d(k)∈[0,1]; Step 3.4: Solve the optimal control law corresponding to the minimum cost function offline to obtain the optimal duty cycle d*(k) for the current cycle.

7. The model predictive control method for a multi-channel switched Buck-Boost converter according to claim 1, characterized in that, Step 4 includes the following sub-steps: Step 4.1: Design an inductor current observer to achieve sampling-free estimation of the inductor current based on the output voltage and duty cycle. The observation equation is: in, This is the observed value of the inductor current; For the output voltage observation value, , For observer gain, and , ; Step 4.2: Design the load impedance observer and define... Establish observation equations to track load changes in real time: in, for The observed values, , For observer gain; Step 4.3: The observed data... and Substitute the values ​​into the model predictive control calculations to replace the actual sampled values, thereby improving control robustness.

8. The model predictive control method for a multi-channel switched Buck-Boost converter according to claim 1, characterized in that, Step 5 includes the following sub-steps: Step 5.1: Monitor the working power status signal in real time. When the working power status signal = 0, it is determined that the current power supply is faulty. Start the power switching program and switch to the next priority power supply within 0.3ms. Update the working power supply voltage and working mode signal. Step 5.2: Based on the optimal duty cycle d*(k) and the power switching state, generate the main switch PWM drive signal, and control the switching on and off of the switch after amplification by the drive circuit; Step 5.3: During the power switching transition period, start the smooth switching algorithm of the startup mode and call the optimal control law of the corresponding mode to ensure that the output voltage is oscillating.

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