Heat balance phase management system of multi-phase staggered Buck converter

Abstract

The invention discloses a heat balance phase management system of a multi-phase staggered Buck converter, and relates to the technical field of power electronics. The system comprises a working phase quantization module, a temperature monitoring module, a closed-loop control module and a fault early warning module, the number of effective working phases is dynamically adjusted through real-time monitoring of the inductive current of each phase and the temperature of a switching tube, a phase working enable signal is generated, and PWM signal modulation is achieved in cooperation with closed-loop control. The system can select a phase with lower temperature to be put into operation according to load current and temperature change, so that inter-phase heat balance is realized, the reliability of the system is improved, and the service life of devices is prolonged. Compared with an existing dynamic phase management technology, interphase heat distribution can be effectively optimized, aging of the switch tube is reduced, and system efficiency and long-term stability are improved.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and particularly to a thermal balance phase management system for a multi-phase interleaved Buck converter. Background Art

[0002] With the continuous increase in the demand for high-power and high-energy-efficiency power supplies in electronic devices, multi-phase interleaved Buck converters are widely used as a common power management solution for microprocessors. Since the load of a microprocessor usually switches dynamically between light load and heavy load, in the heavy load stage, to reduce the current stress of a single device and improve the overall conversion efficiency, all phases need to be put into operation to achieve the sharing of large currents between phases. In the light load stage, if all phases are still kept working, the conversion efficiency of the system will be reduced due to the increase in no-load losses. Therefore, dynamic phase management is required to reduce the number of effective working phases during light load to improve the light load efficiency.

[0003] Existing dynamic phase management technologies usually adopt the "phase rotation switching" scheme, that is, after determining the number of working phases, the load current is sequentially and alternately distributed to each phase to achieve dynamic phase management. However, this scheme has the following deficiencies: First, even if the same type of switching tube device is used, there are still parameter deviations such as parasitic resistance and turn-on loss, and these subtle differences will intensify during long-term operation, resulting in an imbalance in the working temperature distribution of switching tubes in different phases. Second, due to the differences in heat dissipation conditions caused by the PCB layout, the switching tubes in different phases will also have uneven heat distribution in actual applications. Long-term thermal mismatch will reduce the reliability of the device, shorten the service life, and even cause local phase devices to fail due to overheating.

[0004] Therefore, the existing dynamic phase management technologies cannot effectively solve the system reliability problem caused by device thermal imbalance. Summary of the Invention

[0005] To overcome the problem of reduced system reliability caused by the unbalanced temperature distribution of switching tubes in a multi-phase interleaved Buck converter in the prior art, the present invention provides a thermal balance phase management system for a multi-phase interleaved Buck converter, which realizes dynamic phase management and fault diagnosis based on temperature balance.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The thermal balance phase management system for a multi-phase interleaved Buck converter of the present invention includes a working phase quantization module, a temperature monitoring module, a closed-loop control module, and a fault warning module. Each module realizes the thermal balance management, dynamic control, and fault warning of a multi-phase system through signal interaction. The functions and signal flow are as follows:

[0008] The working phase quantization module is configured to sample the output voltage and the phase inductor currents of the multi-phase interleaved Buck converter, monitor the current sharing state among phases, generate a current sharing state signal, and determine the current number of effective working phases by comparing the load current with a preset phase current threshold.

[0009] The temperature monitoring module is configured to monitor the temperature conditions of the switches in each phase, generate temperature diagnosis signals including single-switch temperature anomalies, uneven temperature within a phase, and unbalanced temperature among phases through comprehensive determination of various parameters such as the switch temperature value, safe range, and temperature rise ratio, and output a phase operation enabling signal according to the matching relationship between temperature and load to achieve dynamic temperature balance management for each phase.

[0010] The closed-loop control module is configured to generate a duty cycle modulation signal based on the inductor current, output voltage, and reference voltage signal, successively through a current sharing loop, a voltage loop, and a current loop, and compare it with a phase-shifted carrier signal to generate an initial PWM drive signal P'. k ; Through a logical AND operation with the phase operation enabling signal, finally output the final upper-switch PWM drive signal P 2k-1 , and the lower-switch PWM drive signal P 2k .

[0011] The fault warning module is configured to receive various diagnosis signals from the working phase quantization module and the temperature monitoring module, determine whether there are fault states such as current imbalance, temperature anomaly, or uneven heat distribution in the system, and output corresponding warning signals when anomalies are detected.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0013] By combining load current monitoring and inter-phase temperature distribution, the present invention uses the temperature monitoring module to monitor the temperature states of the switches in each phase in real time, dynamically select the phases with relatively lower temperatures to operate, avoid some phases from being in a high-temperature working state for a long time due to device parameter changes or poor heat dissipation conditions, achieve an even distribution of heat in the multi-phase Buck converter, effectively reduce the aging rate of devices caused by thermal mismatch, and improve the system reliability and device service life.

[0014] The present invention integrates a fault warning module, which can diagnose potential faults such as uneven current sharing, abnormal switch temperature, and thermal mismatch among phases in real time, and output warning signals or turn off abnormal phases in a timely manner, significantly improving the system safety and maintainability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is the technical roadmap of the dynamic thermal balance phase management system of the multi-phase parallel Buck converter provided by the present invention.

[0016] Figure 2 It is a logic schematic diagram of the temperature monitoring module in the dynamic thermal balance phase management system of the multiphase parallel Buck converter provided by the present invention.

[0017] Figure 3 It is a logic schematic diagram of the closed-loop control module in the dynamic thermal balance phase management system of the multiphase parallel Buck converter provided by the present invention.

[0018] Figure 4 It is the phase working timing diagram of the traditional three-phase parallel Buck converter with phase rotation switching.

[0019] Figure 5 It is the phase working timing diagram of the three-phase parallel Buck converter of the dynamic thermal balance phase management system provided by the present invention. Detailed implementation manners

[0020] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It should be understood that these embodiments are only used to illustrate the present invention and do not limit the protection scope of the present invention. Unless otherwise specified, the processes, control strategies and parameter settings involved in implementing the present invention are all well-known common knowledge in the technical field or can be routinely determined by those skilled in the art.

[0021] Figure 1 It shows the overall structure of the thermal balance phase management system of the multi-phase interleaved Buck converter of the present invention. This system mainly includes a working phase quantization module 100, a temperature monitoring module 200, a closed-loop control module 300 and a fault warning module 400. Each module works together to achieve temperature-based phase management.

[0022] The functions of each module and the signal interaction relationship are as Figure 1 shown.

[0023] Refer to Figure 1 , the working phase quantization module 100 is used to collect the output voltage of the multi-phase interleaved Buck converter and the inductor current of each phase, perform current sharing monitoring based on the inductor current sampling result, generate a current sharing status signal sign1 and input it to the fault warning module; at the same time, by comparing the load current with a preset threshold, determine the current number of effective working phases m, and input the m value to the temperature monitoring module 200 to guide subsequent phase temperature monitoring and enable control.

[0024] The temperature monitoring module 200 is composed of a temperature acquisition unit, a temperature monitoring unit, and a phase control unit. Among them, the temperature acquisition unit collects the temperature signals of each phase of the switching tubes in real time through temperature sensors, compares them with a preset safe temperature range, determines whether each switching tube is within the normal operating temperature range, and generates a switching tube temperature anomaly signal sign2. The temperature monitoring unit analyzes the temperature rise conditions of the upper and lower tubes in the same phase, calculates the ratio K of the temperature rise of the upper and lower tubes in the same phase, and generates a thermal imbalance signal sign3 within the phase. At the same time, based on the inter-phase temperature distribution, an inter-phase thermal imbalance signal sign4 is output. The phase control unit receives the effective number of working phases m from the working phase quantization module, and based on the monitored average temperature of each phase, dynamically screens m phases with relatively lower temperatures, and generates phase working enable signals F1 to F N , which are transmitted to the closed-loop control module 300 for realizing dynamic input or sleep control of each phase.

[0025] The closed-loop control module 300 is responsible for the closed-loop control of the multi-phase converter. After receiving the voltage and inductor current from the working phase module 100, the closed-loop control module 300 will generate the initial PWM drive signal P' of each phase under the coordinated action of the current sharing loop, voltage loop, and current loop k , and then perform a logical AND operation in combination with the phase working enable signal input by the temperature monitoring module, and output the final PWM drive signal to the corresponding switching tubes of the interleaved parallel Buck converter to realize the on-off control of each switching tube.

[0026] The fault warning module 400 is responsible for the fault information processing and warning of the system. The fault warning module 400 receives the current sharing status signal sign1 output by the working phase quantization module, and issues a warning if the current distribution is uneven. The fault warning module also receives the switching tube temperature anomaly signal sign2, the thermal imbalance signal sign3 within the phase, and the inter-phase thermal imbalance signal sign4 output by the temperature monitoring module. If a fault or temperature anomaly is found, it can cut off the phase in time or issue a warning signal to ensure the safety of the system.

[0027] To further clarify the operating mechanism of the working phase quantization module 100, the following describes its specific process in detail:

[0028] Data acquisition and input processing: The data sampling unit collects the converter output voltage V through a voltage sensor o , and collects the inductor current I of each phase through a current sensor k , and the sampling signals are synchronously input to the digital processing chip, and the sampling frequency is f.

[0029] Current sharing monitoring and status judgment: The current sharing monitoring unit is based on the sampled inductor current I k , and obtains the average value I of the N-phase inductor currentsav =(I1 + I2 + … + I k ) / N. When |I av - I k | < ε (ε is the allowable current sharing error), the output current sharing status signal sign1 k = 0; otherwise, the output sign1 k = 1, which is used to indicate the inter-phase current sharing imbalance.

[0030] Load current calculation and phase decision: The phase decision unit calculates the load current I sum = I1 + I2 + … + I N , and successively compares it with the preset phase current thresholds I th1 to I thN , and divides the system power range, specifically:

[0031] When I sum ≤ I th1 , it is in the first power range, and the effective number of working phases m = 1 is determined; when I th1 < I sum ≤ I th2 , it is in the second power range, and the effective number of working phases m = 2 is determined; and so on; when I sum > I th(N-1) , it is in the Nth power range, and the effective number of working phases m = N is determined. The preset current thresholds I th1 to I th(N-1) are specific parameters set according to experiments or system operating characteristics

[0032] Finally, the phase decision unit outputs the effective number of working phases m to the temperature monitoring module 200 as the basis for subsequent phase screening and enabling control.

[0033] The temperature monitoring module 200 is responsible for real-time monitoring of the temperature status of each phase switch tube and executing corresponding control strategies based on the monitoring results. The following describes its specific working process in detail: Figure 2 Detailed description of its specific working process:

[0034] The temperature acquisition unit acquires the temperature of the kth phase switch tube through a temperature sensor, which are respectively recorded as: the temperature of the upper tube of the kth phase T 2k-1 and the temperature of the lower tube of the kth phase T 2k . The sampled data is quantized by the sampling frequency f and converted into a digital signal. Refer to Figure 2 , the acquired temperature signal T first passes through a window comparison module. The window comparison module sets the upper and lower limits as T max , T min , T max is the maximum junction temperature allowed for the internal silicon chip of the switch tube, and T minis the temperature when the switching device is not working at room temperature. If the temperature of the switching device exceeds T max it will cause thermal runaway or permanent damage. If the temperature is lower than T min there may be a situation of temperature sensor failure. If the temperature T of any switching device 2k-1 / 2k >T max and T 2k-1 / 2k <T min , then the temperature abnormal signal sign2 of the corresponding switching device 2k-1 / 2k = 1, which is input to the fault warning module 400. The fault warning module 400 issues a warning signal and outputs W k = 0, and the closed-loop control module is linked to turn off the PWM drive signal of the k-th phase.

[0035] Then, the temperature T of the upper transistor of the k-th phase and the temperature T of the lower transistor collected 2k-1 are input to the arithmetic logic unit ALU to calculate the temperature rise of the two transistors respectively. ΔT 2k 2k-1 = T 2k-1 - T0, ΔT 2k 2k = T 2k - T0, where T0 is the ambient temperature. Then, the ratio K of the temperature rise of the upper and lower switching transistors of the k-th phase is K = ΔT 2k-1 / ΔT 2k . If the ratio K of the temperature rise of the upper and lower transistors of the same phase of the k-th phase exceeds the preset range [K min , K max , a phase internal heat imbalance signal sign3 k = 1 is generated. If the ratio K of the temperature rise of the upper and lower transistors of the same phase of the k-th phase does not exceed the preset range [K min , K max , a phase internal heat imbalance signal sign3 k = 0 is generated. The preset range [K min , K max should be set in combination with the safe operating area parameters of the two switching devices, and can be determined by those skilled in the art according to the device characteristics and actual working conditions. When K≥K max , the temperature rise of the upper transistor of this phase is greater than that of the lower transistor, indicating that the upper transistor has been working under a heavier load for a long time, while the other transistor is working under a light load, which will lead to system instability. According to the parameter K, the specific parameters of the two switching devices in the appropriate phase can be guided to be selected to reduce this imbalance.

[0036] The average value of the temperature T of the upper transistor and the temperature T of the lower transistor of the same phase collected 2k-1 is obtained to get the phase average temperature T of the k-th phase 2k avk = (T 2k-1 + T 2k ) / 2. The phase average temperature T of each phase avk ​And the effective number of working phases m are jointly input into the logic operation unit, and first, the average value T of the N-phase phase average temperature is calculated av =(T av1 +T av2 +…+T avN ) / N, and the difference is calculated with the phase average temperature T of each phase respectively. If |T avk -T av |<ε avk (ε T is the maximum value of the deviation of the phase average temperature from the average temperature allowed by the thermally balanced multi-phase parallel Buck converter), then the phase thermal equilibrium effect is good, and the inter-phase thermal imbalance signal sign4 T of this phase = 0. Otherwise, the phase is thermally imbalanced, and the inter-phase thermal imbalance signal sign4 k = 1. Sort the N-phase phase average temperatures, and output the m-th largest temperature among them as T k , compare T m with the phase average temperature T of each phase m input into the comparator. If T avk >T avk , output the phase operation enable signal F m of the k-th phase = 0; if T k ≤T avk , output the phase operation enable signal F m of the k-th phase = 1; the phase enable signals F1 to F k are output to the closed-loop control module 300 for phase dynamic control. N The working process of the closed-loop control module 300 is as follows. For the specific process, see

[0037] : Figure 3 :

[0038] Current sharing loop: Input the inductor currents I1, I2, …, I N into the current sharing loop, and calculate the average value I of the N-phase inductor currents av =(I1 + I2 + … + I N ) / N. I av is used as the current sharing reference and input into the subsequent current sharing loop. The inductor current I of each phase k is compared with the calculated average value I of the N-phase inductor currents av to obtain the current sharing error signal: e Ik = I av -I k , where: e Ik represents the current sharing error signal of the k-th phase; the error signal is used for closed-loop control to adjust the current distribution of each phase to make all phases tend to be balanced.

[0039] Voltage loop: Input the output voltage V collected by the working phase quantization moduleo and the given reference voltage V Ref . Add the original given reference voltage V o to the equal - current error signal e of each phase Ik to output a corrected reference voltage V' Refk = V Ref + e Ik . Compare the output voltage V o with the corrected reference voltage V' of each phase Refk to obtain the voltage error signal e Vk = V' Refk - V o , and this signal is used to maintain the output voltage at the desired level.

[0040] Current loop: Input the voltage error e Vk into the corresponding proportional - integral (PI) control unit to output a current reference quantity I Refk . The system first subtracts the reference current I Refk from the inductance current I of each phase k to obtain the current error signal e of each phase Ik = I Refk - I k . This error signal e Ik is then input into the proportional - integral control unit to output the modulation signal V of the k - th phase rk , V rk ∈[0, 1]. Its purpose is to let the proportional - integral (PI) control unit continuously adjust the PWM drive signal of the corresponding phase so that the actual inductance current I k tracks the reference current I Refk , thereby achieving precise current control and current sharing.

[0041] PWM drive signal modulation unit: After determining the total number of phases m currently in operation, re - number the phases actually in operation in sequence. The sequence number of the k - th phase (original number) in the effective phases is denoted as k'. Phase - shift the initial saw - tooth carrier wave of the k - th phase (the f c of the saw - tooth carrier wave is the switching frequency of the switching tube, the highest value of the saw - tooth carrier wave is 1, and the lowest value is 0) by an angle of 360°(k' - 1) / m, where k' = 1, 2, …, m. Then, compare the phase - shifted saw - tooth carrier wave V ck with the modulation signal V rk as follows:

[0042]

[0043] Thereby generating the initial PWM drive signal P' of the k - th phase k. Through this phase-shifting method, the switching timings of each phase can be dispersed in a multi-phase interleaved Buck converter.

[0044] Phase enabling and final PWM drive signal generation: After obtaining the initial PWM drive signal P', k it is then logically ANDed with the phase operating enable signal F k to generate the final PWM drive signal: P 2k = P' k ∧F k , When the phase is not allowed to operate (F k = 0), the PWM output is turned off, and the PWM drive signal P of the lower switch of phase k 2k is always low, and the PWM drive signal P of the upper switch of phase k 2k-1 is always high. Conversely, when the phase is allowed to operate (F k = 1), the PWM output remains normal, and the PWM drive signal P of the lower switch of phase k 2k is a PWM drive signal with a duty cycle of V rk (the value of V rk is the duty cycle D), and the PWM drive signal P of the upper switch of phase k 2k-1 is a PWM drive signal with a duty cycle of 1 - V rk . Through the above process, the closed-loop control module realizes dynamic phase management and precise control based on the coordination of voltage, current, current sharing, and temperature.

[0045] The working logic of the fault warning module 400 is as follows:

[0046] The fault warning module 400 receives the current sharing status signal sign1 provided by the working phase quantization module, as well as the switch temperature abnormal signal sign2, the internal phase thermal imbalance signal sign3, and the inter-phase thermal imbalance signal sign4 provided by the temperature monitoring module.

[0047] When the current sharing status signal sign1 of the k-th phase k = 1, it is determined that there is inter-phase current sharing imbalance, and a current sharing warning signal is output to indicate that the current deviation of the k-th phase exceeds the allowable current sharing deviation.

[0048] When the switch temperature abnormal signal sign2 of the k-th phase 2k-1 = 1 or sign2 2k = 1, it is determined that there is a temperature abnormality in the switch of the k-th phase, and a control signal W k is immediately generated and sent to the closed-loop control module to trigger the shutdown of this phase, and a temperature warning signal is synchronously output to indicate that the device temperature is abnormal.

[0049] When the internal phase thermal imbalance signal sing3 of the k-th phase kWhen it is equal to 1, it is determined that the temperature rise difference between the upper and lower switches of the k-th phase is relatively large, indicating a situation of unbalanced load, and an in-phase thermal imbalance warning signal is output.

[0050] When the inter-phase thermal imbalance signal sign4 of the k-th phase k is equal to 1, it is determined that there is uneven inter-phase thermal distribution, the temperature deviation value of the k-th phase exceeds the allowable range, and an inter-phase thermal imbalance warning signal is output to remind the user to check the device and the temperature sampling frequency setting.

[0051] To verify the effectiveness of the dynamic thermal balance phase management system of the present invention, the following combines the application scenario of a typical three-phase interleaved parallel Buck converter to demonstrate the advantages of the present invention compared with the existing dynamic phase management strategy.

[0052] In the traditional dynamic phase cycling management strategy, the system dynamically adjusts the number of effective working phases according to the load current I sum For example, when I sum is in the medium load range, the system enables 2 phases to achieve the best conversion efficiency (T s = 1 / f s , f s is the phase cycling switching frequency), and the working timing diagram is as Figure 4 shown. However, this scheme does not consider the differences in device parameters of each phase switch and the differences in actual heat dissipation conditions caused by PCB layout, resulting in obvious differences in the temperatures of each phase switch during long-term operation, and it is difficult to achieve system thermal balance.

[0053] In contrast, the thermal equilibrium dynamic phase management strategy proposed by the present invention effectively improves the above deficiencies through real-time temperature monitoring and dynamic phase allocation. As Figure 5 shown: (1) At the 0 moment, the temperature monitoring module detects that the temperature of the switch of the 3rd phase is the highest, the system turns off the 3rd phase, and only the 1st and 2nd phases are enabled to operate for a duration of T = 1 / f, where f is the temperature sampling frequency; (2) At the T moment, the temperature of the 3rd phase is still higher than that of other phases, the system continues to turn off the 3rd phase, and only the 1st and 2nd phases work; (3) At the 2T moment, the temperature of the 1st phase rises to the highest, the system switches to the 2nd and 3rd phases to work, and the 1st phase is turned off; the remaining phases perform temperature equilibrium management in turn according to this rule, and continuously switch dynamically to achieve long-term thermal distribution equilibrium.

[0054] By dynamically screening the phases with relatively low temperatures to put into operation, the present invention can achieve dynamic equilibrium of the inter-phase heat distribution, reduce the risk of long-term high-temperature operation of the switches, and significantly improve the thermal balance of the system and the reliability of the devices.

[0055] The terms "Buck converter", "phase", etc. in the present invention are common expressions in the fields of power electronics and control engineering and are used to describe the present technical solution. Their specific meanings should be understood in the context and should not be regarded as limitations on the system structure or functions of the present invention.

[0056] The terms "receive", "control", "input", etc. in the present invention should be understood in a broad sense, including direct or indirect, physical or logical, wired or wireless connection and signal transmission, and also including software and hardware control and the process processed by an intermediate unit.

[0057] Each "module" and "unit" in the present invention is only a functional and logical division and does not specifically refer to a specific physical structure. During implementation, discrete or integrated design can be carried out according to requirements.

[0058] The terms "the k-th phase", "within a phase", "between phases", etc. in the present invention are only used to distinguish the relative relationships of different phases, modules or components and do not have limitations on space, structure or arrangement order. "k = 1, 2,..., N" is used to represent any phase number, and N is the total number of phases.

[0059] Those skilled in the art should be aware that, without departing from the core technical solution of the present invention, various equivalent replacements, functional adjustments or partial improvements made to the system structure, signal flow, control strategy or module division in the present invention shall fall within the protection scope of the present invention.

Claims

1. A thermal balance phase management system for a multi-phase interleaved Buck converter, characterized in that: include: The working phase quantization module is used to collect the output voltage and the inductor current of each phase of the multi-phase interleaved Buck converter, and judge the current balance between the phases through current sharing monitoring to generate a current sharing state signal; it is also used to calculate the sum of the inductor currents of each phase to obtain the load current, and compare the load current with a preset phase current threshold to determine the current effective working phase number m; The temperature monitoring module is used to collect the temperature of the switch tube of each phase and compare the temperature with the preset normal working temperature range to generate a switch tube temperature abnormality signal; it is also used to calculate the temperature rise ratio of the upper and lower switch tubes of the same phase, and compare it with the preset range, and generate a phase thermal imbalance signal according to the comparison result; further according to the effective working phase number m, select the mth largest phase average temperature value T from the phase average temperature of each phase m , and the mth largest phase average temperature value T m Compare with the average temperature of each phase to output a phase operation enable signal and generate a phase thermal imbalance signal; The closed-loop control module is used to receive the inductor current of each phase, a given reference voltage and an output voltage, and generate an initial PWM drive signal through a current sharing loop, a voltage loop and a current loop; and perform a logical AND operation on the initial PWM drive signal and the working enable signal of each phase output by the temperature monitoring module to output a final PWM drive signal.

2. The thermal balance phase management system of a multi-phase interleaved Buck converter according to claim 1, characterized in that: The working phase quantization module compares the load current with a preset load current threshold, divides the load current into N power intervals, and outputs the corresponding effective working phase number m, specifically: When the load current is less than or equal to the first threshold, it is determined that the load is in the first power interval, and the output effective working phase number m=1; when the load current is greater than the first threshold and less than or equal to the second threshold, it is determined that the load current is in the second power interval, and the output effective working phase number m=2; the remaining power intervals are similarly determined, and when the load current is greater than the N-1th threshold, it is determined that the load current is in the Nth power interval, and the output effective working phase number m=N.

3. The thermal balance phase management system of a multi-phase interleaved Buck converter according to claim 1, characterized in that: The temperature monitoring module further comprises: The temperature acquisition unit is used to collect the temperature signal of each phase switch tube and convert it into a digital signal at the temperature sampling frequency; it is also used to compare the temperature value T of each switch tube with the preset normal working temperature range and generate a switch tube temperature abnormality signal; The temperature monitoring unit is used to calculate the ratio K of the temperature rise of the upper and lower switch tubes of the same phase, and compare K with the preset range [K min , K max ] to compare, and generate a phase thermal imbalance signal according to the comparison result; A phase control unit is used to calculate the average temperature of the two switching tubes of each phase, that is, the phase average temperature, and select the mth largest phase average temperature value among all phase average temperatures; compare the mth largest phase average temperature value with the phase average temperature of each phase, output a phase work enable signal; and generate a phase thermal imbalance signal based on the phase temperature balance.

4. The thermal balance phase management system of a multi-phase interleaved Buck converter according to claim 1, characterized in that: The closed-loop control module further comprises: A current sharing control unit, used for calculating an average inductor current according to the N-phase inductor current, and comparing the average inductor current with the inductor current of each phase to generate a current sharing error signal of each phase; A voltage control unit is used to add the current sharing error signal of each phase to a given reference voltage to generate a phase reference voltage of each phase, and compare the phase reference voltage of each phase with the output voltage to generate a voltage error signal of each phase; the voltage error signal of each phase is processed by a proportional-integral control unit to generate a target reference current of each phase; A current control unit, used for comparing the target reference current of each phase with the inductor current of the corresponding phase, generating a phase current error signal of each phase, and the current error signal of each phase is processed by the proportional-integral control unit to generate a duty cycle modulation signal of each phase; The PWM drive signal modulation unit is used to compare the duty cycle modulation signal of each phase with the phase-shifted carrier signal of the corresponding phase to generate the initial PWM drive signal of each phase; it is also used to perform a logical AND operation on the initial PWM signal and the corresponding phase working enable signal to output the final PWM drive signal.

5. The thermal balance phase management system of the multi-phase interleaved Buck converter according to claim 1, characterized in that: The system further includes a fault warning module, which includes: A signal receiving unit, used to receive the current sharing state signal generated by the working phase quantization module, and the switch tube temperature abnormality signal, the intra-phase thermal imbalance signal and the inter-phase thermal imbalance signal generated by the temperature monitoring module; The early warning judgment unit is configured as follows: Determine the current balance of each phase according to the current sharing state signal, and generate a first warning signal if there is current imbalance; Determine the temperature state of a single tube according to the abnormal temperature signal of the switch tube, and generate a second warning signal if the temperature of any switch tube is abnormal; Determine the load balance of the upper and lower tubes of the same phase according to the intra-phase thermal imbalance signal, and generate a third warning signal if the load is unbalanced; The inter-phase temperature balance is determined according to the inter-phase thermal imbalance signal, and a fourth warning signal is generated if the average temperature deviation of any phase exceeds an allowable range.

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