Control method and device for preventing pump-generated voltage backflow based on synchronous BUCK circuit

Abstract

This invention relates to the field of motor control technology, specifically to a control method and apparatus for preventing backflow of pump-generated voltage based on a synchronous BUCK circuit. The method includes: executing switching control of the synchronous BUCK circuit according to a set frequency and duty cycle of the switching transistors, and recording the values ​​of Vo and Vin once per switching control cycle; upon reaching a predetermined judgment period, reading the Vo and Vin values ​​recorded in each switching control cycle within the judgment period; determining whether a pump-generated voltage has occurred based on the changes in the Vo and Vin values ​​recorded in each switching control cycle within the judgment period; and if so, turning off both switching transistors Q1 and Q2. By acquiring the values ​​of Vin and Vo, the state of the synchronous BUCK circuit is determined using these two voltage values. When it is determined that a pump-generated voltage has occurred, both switching transistors Q1 and Q2 are turned off. That is, by controlling the switching state and duty cycle of Q1 and Q2, backflow of pump-generated voltage energy is prevented.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to a control method and device for preventing pump-generated voltage backflow based on a synchronous BUCK circuit. Background Technology

[0002] Synchronous BUCK circuits offer advantages such as high efficiency and a wide input voltage range, making them suitable for DC power supply in high-power AC servo motor amplifiers. Their circuit topology is as follows: Figure 1 As shown, its basic principle is to utilize the energy storage characteristics of inductor L, and to achieve a specific ratio reduction in output voltage compared to input voltage by controlling the continuous switching action of switching transistors Q1 and Q2 at a certain frequency and with a specific duty cycle.

[0003] In a system that uses a synchronous BUCK circuit to power an AC servo motor amplifier, the motor, as an unstable inductive load, experiences significant fluctuations in its load rate with each start and stop. Furthermore, during rapid braking and when the potential energy carried by the motor decreases vertically, substantial energy is generated and pumped back into the capacitor through the amplifier, creating a pump-generated voltage. For the synchronous BUCK circuit, as Vo increases, the duty cycle of switch Q1 decreases. Since the duty cycle of switch Q2 is symmetrical to that of switch Q1, it increases. At this point, the inductor L, switch Q2, and the body diode of switch Q1 form a boost circuit from Vo to Vin. The system is in a reverse current state, causing the input voltage Vin to rise rapidly, jeopardizing system safety. Summary of the Invention

[0004] To address the aforementioned problems, embodiments of the present invention provide a control method and apparatus for preventing pump-generated voltage backflow based on a synchronous BUCK circuit.

[0005] One aspect of this invention provides a control method for preventing pump-generated voltage backflow based on a synchronous BUCK circuit, comprising:

[0006] The synchronous BUCK circuit performs switching control according to the set frequency and duty cycle of the switching transistor, and records the values ​​of Vo and Vin once in each switching control cycle;

[0007] When the predetermined judgment period is reached, the values ​​of Vo and Vin recorded in each switch control cycle within the judgment period are read, where the judgment period is longer than the switch control cycle.

[0008] The change in the values ​​of Vo and Vin recorded in each switch control cycle within the judgment period is used to determine whether pump-generated voltage is generated.

[0009] If so, turn off both switching transistors Q1 and Q2;

[0010] If not, return to the step of performing the switching control of the synchronous BUCK circuit according to the set frequency and duty cycle of the switching transistor, and recording the values ​​of Vo and Vin once for each switching control cycle.

[0011] Optionally, the step of determining whether a pump-generated voltage is generated by utilizing the changes in the values ​​of Vo and Vin recorded in each switch control cycle within the read judgment period includes:

[0012] Calculate the average value of Vin recorded within the judgment period, Vinavg, and determine whether the calculated average value Vinavg is greater than the preset threshold Vinavgcs.

[0013] If the average value Vinavg is greater than the preset threshold Vinavgcs, calculate the first average value Voavg of Vo recorded within the judgment period; calculate the first difference ΔVoavg between the average value of Vo recorded in the second half of the judgment period and the average value of Vo recorded in the first half of the judgment period; calculate the difference ΔVinavg between the average value of Vin recorded in the second half of the judgment period and the average value of Vin recorded in the first half of the judgment period.

[0014] Determine whether the first average value Voavg is greater than the preset threshold Voavgcs, whether the first difference ΔVoavg is greater than the preset threshold ΔVoavgcs, and whether the difference ΔVinavg is greater than the preset threshold ΔVinavgcs;

[0015] If the first average value Voavg is greater than the preset threshold Voavgcs, the first difference ΔVoavg is greater than the preset threshold ΔVoavgcs, and the difference ΔVinavg is greater than the preset threshold ΔVinavgcs, then a pumping voltage is determined to be generated.

[0016] Optionally, the preset threshold Vinavgcs is the maximum allowable input voltage of the synchronous BUCK circuit plus a fixed value; the preset threshold Voavgcs is 101% of the target value of the output voltage of the synchronous BUCK circuit; the preset threshold ΔVoavgcs is 0; the preset threshold ΔVinavgcs is 0.

[0017] Optionally, after turning off both switching transistors Q1 and Q2, the following steps are also included:

[0018] Record the value of Vo according to the switching control cycle, and when the predetermined judgment cycle is reached, read the value of Vo recorded in each switching control cycle within the judgment cycle;

[0019] Calculate the second average value of Vo recorded within the judgment period, Voavg, and calculate the second difference ΔVoavg between the average value of Vo recorded in the second half of the judgment period and the average value of Vo recorded in the first half of the judgment period.

[0020] Determine whether the second average value Voavg is less than the preset threshold Voavgcs and whether the second difference ΔVoavg is less than the preset threshold ΔVoavgcs;

[0021] If the second average value Voavg is less than the preset threshold Voavgcs and the second difference ΔVoavg is less than the preset threshold ΔVoavgcs, the process of returning to the synchronous BUCK circuit switching control according to the set frequency and duty cycle of the switching transistors, and recording the values ​​of Vo and Vin once in each switching control cycle, otherwise the switching transistors Q1 and Q2 remain off.

[0022] Optionally, the control methods also include:

[0023] Determine the duty cycle D of switch Q2 Q2 At the same time, determine the duty cycle D. Q2 Is it less than the preset threshold D? Q2max ;

[0024] At duty cycle D Q2 Not less than the preset threshold D Q2max In this case, the pump-generated voltage is determined, and thus both switching transistors Q1 and Q2 are turned off; where D Q2max The following conditions must be met:

[0025] (1 - D) Q2max ) < (Vor / Vinrmax)

[0026] Where Vor is the target output voltage of the synchronous BUCK circuit, and Vinrmax is the rated maximum input voltage of the synchronous BUCK circuit.

[0027] Another aspect of the present invention provides a control device for preventing pump-generated voltage backflow based on a synchronous BUCK circuit, comprising:

[0028] The constant voltage control module is used to execute the switching control of the synchronous BUCK circuit according to the set frequency and duty cycle of the switching transistor, and records the values ​​of Vo and Vin once in each switching control cycle;

[0029] The data reading module is used to read the Vo and Vin values ​​recorded in each switch control cycle within the predetermined judgment period when the judgment period is reached, where the judgment period is longer than the switch control cycle.

[0030] The pump-up voltage determination module is used to determine whether pump-up voltage is generated by using the changes in the values ​​of Vo and Vin recorded in each switch control cycle within the judgment period. If it is determined that pump-up voltage is generated, it returns to the reverse current control module; if it is determined that pump-up voltage is not generated, it returns to the constant voltage control module.

[0031] The reverse current control module is used to turn off both switching transistors Q1 and Q2.

[0032] Optional, a pump-up voltage determination module, specifically used for

[0033] Calculate the average value of Vin recorded within the judgment period, Vinavg, and determine whether the calculated average value Vinavg is greater than the preset threshold Vinavgcs.

[0034] If the average value Vinavg is greater than the preset threshold Vinavgcs, calculate the first average value Voavg of Vo recorded within the judgment period; calculate the first difference ΔVoavg between the average value of Vo recorded in the second half of the judgment period and the average value of Vo recorded in the first half of the judgment period; calculate the difference ΔVinavg between the average value of Vin recorded in the second half of the judgment period and the average value of Vin recorded in the first half of the judgment period.

[0035] Determine whether the first average value Voavg is greater than the preset threshold Voavgcs, whether the first difference ΔVoavg is greater than the preset threshold ΔVoavgcs, and whether the difference ΔVinavg is greater than the preset threshold ΔVinavgcs;

[0036] If the first average value Voavg is greater than the preset threshold Voavgcs, the first difference ΔVoavg is greater than the preset threshold ΔVoavgcs, and the difference ΔVinavg is greater than the preset threshold ΔVinavgcs, then a pumping voltage is determined to be generated.

[0037] Optionally, the preset threshold Vinavgcs is the maximum allowable input voltage of the synchronous BUCK circuit plus a fixed value; the preset threshold Voavgcs is 101% of the target value of the output voltage of the synchronous BUCK circuit; the preset threshold ΔVoavgcs is 0; the preset threshold ΔVinavgcs is 0.

[0038] Optional, also includes:

[0039] The data recording module is used to record the value of Vo according to the switching control cycle after both switching transistors Q1 and Q2 are turned off, and to read the value of Vo recorded in each switching control cycle within the judgment period when the predetermined judgment period is reached.

[0040] The data calculation module is used to calculate the second average value Voavg of the Vo values ​​recorded within the judgment period, and to calculate the second difference ΔVoavg between the average value of Vo recorded within the second half of the judgment period and the average value of Vo recorded within the first half of the judgment period.

[0041] The data judgment module is used to determine whether the second average value Voavg is less than the preset threshold Voavgcs and whether the second difference ΔVoavg is less than the preset threshold ΔVoavgcs. If the second average value Voavg is less than the preset threshold Voavgcs and the second difference ΔVoavg is less than the preset threshold ΔVoavgcs, the module returns to the constant voltage control module; otherwise, it returns to the reverse current control module.

[0042] Optional, also includes:

[0043] The duty cycle determination module is used to determine the duty cycle D of the switching transistor Q2. Q2 At the same time, determine the duty cycle D. Q2 Is it less than the preset threshold D? Q2max ;

[0044] At duty cycle D Q2 Not less than the preset threshold D Q2max In this case, the pump-generated voltage is determined, and thus both switching transistors Q1 and Q2 are turned off; where D Q2max The following conditions must be met:

[0045] (1 - D) Q2max ) < (Vor / Vinrmax)

[0046] Where Vor is the target output voltage of the synchronous BUCK circuit, and Vinrmax is the rated maximum input voltage of the synchronous BUCK circuit.

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows: by collecting the values ​​of Vin and Vo, the state of the synchronous BUCK circuit is determined by using the two collected voltage values. When it is determined that a pump-generated voltage is generated, both switching transistors Q1 and Q2 are turned off. That is, by controlling the switching state and duty cycle of Q1 and Q2, the reverse flow of pump-generated voltage energy is prevented. Attached Figure Description

[0048] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, are not intended to limit the scope of the invention. In the drawings:

[0049] Figure 1 The circuit topology diagram for the synchronous BUCK circuit;

[0050] Figure 2A flowchart illustrating a control method for preventing pump-generated voltage backflow based on a synchronous BUCK circuit, provided in an embodiment of the present invention;

[0051] Figure 3 The changing trends of Vo and Vin after the pump-generated voltage is generated in the synchronous BUCK circuit;

[0052] Figure 4 This is a schematic diagram of a control device for preventing pump-generated voltage backflow based on a synchronous BUCK circuit, provided as an embodiment of the present invention. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. Here, the illustrative embodiments and descriptions of this invention are used to explain the invention, but are not intended to limit the invention.

[0054] See Figure 2 The present invention provides a control method for preventing pump-generated voltage backflow based on a synchronous BUCK circuit, comprising:

[0055] S100 executes the switching control of the synchronous BUCK circuit according to the set frequency and duty cycle of the switching transistor, and records the values ​​of Vo and Vin once in each switching control cycle.

[0056] In practice, the switching control cycle is the time it takes for the switching transistor to turn on and off once. The switching control cycle can be denoted as T, and the values ​​of Vo and Vin are recorded once within each switching control cycle T.

[0057] S110, when the predetermined judgment period is reached, read the values ​​of Vo and Vin recorded in each switch control cycle within the judgment period, where the judgment period is longer than the switch control cycle.

[0058] In practice, the predetermined judgment period can be Tn, which is generally 2T-10T, that is, data is read after every 2-10 Vo and Vin values ​​are recorded.

[0059] S120: Determine whether a pump-generated voltage is generated by using the changes in the values ​​of Vo and Vin recorded in each switch control cycle within the judgment period. If yes, execute S130; otherwise, return to S100.

[0060] In practice, the specific process of determining whether a pump-generated voltage is generated may include: calculating the average value Vinavg of Vin recorded within the judgment period Tn, and determining whether the calculated average value Vinavg is greater than the preset threshold Vinavgcs.

[0061] If the average value Vinavg is not greater than the preset threshold Vinavgcs, return to execute S100, execute the switching control of the synchronous BUCK circuit according to the set frequency and duty cycle of the switching transistor, and record the values ​​of Vo and Vin once in each switching control cycle.

[0062] When the average value Vinavg is greater than the preset threshold Vinavgcs, i.e., after determining that Vin has increased, calculate the first average value of Vo recorded within the judgment period Tn, Voavg; calculate the first difference ΔVoavg between the average value of Vo recorded in the second half of the judgment period Tn and the average value of Vo recorded in the first half of the judgment period Tn; calculate the difference ΔVinavg between the average value of Vin recorded in the second half of the judgment period Tn and the average value of Vin recorded in the first half of the judgment period Tn.

[0063] Simultaneously, it determines whether the first average value Voavg is greater than the preset threshold Voavgcs, whether the first difference ΔVoavg is greater than the preset threshold ΔVoavgcs, and whether the difference ΔVinavg is greater than the preset threshold ΔVinavgcs. The preset threshold Vinavgcs is the maximum allowable input voltage of the synchronous BUCK circuit plus a fixed value; the preset threshold Voavgcs is 101% of the target output voltage value of the synchronous BUCK circuit; the preset threshold ΔVoavgcs is 0; the preset threshold ΔVinavgcs is 0. The fixed value can be 20, 30, etc., ensuring that the preset threshold Vinavgcs is greater than the maximum allowable input voltage of the synchronous BUCK circuit. This prevents the servo motor from frequently generating pump voltage in practical applications, even when the energy is low, thus avoiding frequent switching of transistors Q1 and Q2, which could affect system stability.

[0064] If the first average value Voavg is greater than the preset threshold Voavgcs, the first difference ΔVoavg is greater than the preset threshold ΔVoavgcs, and the difference ΔVinavg is greater than the preset threshold ΔVinavgcs, then a pump-generated voltage is determined to be generated. In step S130, both switching transistors Q1 and Q2 are turned off. Otherwise, if no pump-generated voltage is determined to be generated, the process returns to step S100. The switching control of the synchronous BUCK circuit is executed according to the set frequency and duty cycle of the switching transistors, and the values ​​of Vo and Vin are recorded once in each switching control cycle.

[0065] S130 turns off both switching transistors Q1 and Q2.

[0066] In practice, once the pump-generated voltage is determined, both switching transistors Q1 and Q2 are turned off, thereby blocking the reverse flow of the pump-generated voltage.

[0067] After both switching transistors Q1 and Q2 are turned off, the reverse current prevention control state is entered. In this state, the change in the value of Vo can be used to determine whether the pumping voltage generation of the system has ended.

[0068] Specifically, it may include: S131, recording the value of Vo according to the switch control cycle T, and reading the value of Vo recorded in each switch control cycle T within the judgment cycle Tn when the predetermined judgment cycle Tn is reached;

[0069] S132, calculate the second average value Voavg of the Vo values ​​recorded within the judgment period Tn, and calculate the second difference ΔVoavg between the average value of Vo recorded within the second half of the judgment period Tn and the average value of Vo recorded within the first half of the judgment period Tn.

[0070] S133: Determine whether the second average value Voavg is less than the preset threshold Voavgcs and whether the second difference ΔVoavg is less than the preset threshold ΔVoavgcs. If the second average value Voavg is less than the preset threshold Voavgcs and the second difference ΔVoavg is less than the preset threshold ΔVoavgcs, determine that the pumping voltage has ended, and return to S100 to execute the switching control of the synchronous BUCK circuit according to the set frequency and duty cycle of the switching transistors, and record the values ​​of Vo and Vin once in each switching control cycle. Otherwise, continue to execute S130 to turn off the switching transistors Q1 and Q2.

[0071] In practice, in a system that uses a synchronous BUCK circuit to power an AC servo motor amplifier, if the system has both proportional and integral control, the trends of Vo and Vin after the servo motor generates the pumped voltage are as follows: Figure 3 As shown; let the duty cycle of switch Q1 be D. Q1 The duty cycle of Q2 is D. Q2 If we ignore the dead time, then we have: D Q2 =1- D Q1 ; Figure 3 At time t0, the servo motor begins to generate pump voltage, and Vo begins to rise; at time t1, Vo rises to a certain level (in reality, the rise in Vo is very small and therefore not obvious in the figure), and in order to maintain the stability of Vo, D... Q1 Decrease, D Q2As the voltage increases, the system balance is disrupted, and the system becomes a Boost circuit from Vo to Vin. During the period t1-t2, the servo motor continuously generates pumped voltage, and Vo is maintained at the target output voltage value under the control of the system. Energy is transferred from Vo to Vin, causing Vin to gradually increase. After time t2, the servo motor stops generating pumped voltage, the system disconnects from the Boost circuit, returns to the normal synchronous BUCK circuit, and Vin decreases. For the entire system, the period t1-t2 becomes a reverse flow state of pumped voltage. When Vin rises above the highest voltage Vinmax that the system can withstand, there is a risk of overvoltage damage to the system components.

[0072] In one implementation, according to the above-mentioned pump-generated voltage generation period, in order to maintain the stability of Vo, D Q1 Decrease, D Q2 The increased characteristic can also be determined based on D. Q2 The change in voltage is used to determine whether a pump-generated voltage is generated. Specifically, the system determines the duty cycle D of the switching transistor Q2 in real time. Q2 At the same time, determine the duty cycle D. Q2 Is it less than the preset threshold D? Q2max ;

[0073] At duty cycle D Q2 Not less than the preset threshold D Q2max In this case, the pump-generated voltage is determined, and thus both switching transistors Q1 and Q2 are turned off; where D Q2max The following conditions must be met:

[0074] (1 - D) Q2max ) < (Vor / Vinrmax)

[0075] Where Vor is the target output voltage of the synchronous BUCK circuit, and Vinrmax is the rated maximum input voltage of the synchronous BUCK circuit.

[0076] The technical solution of this invention collects the values ​​of Vin and Vo, and uses the two collected voltage values ​​to determine the state of the synchronous BUCK circuit. When it is determined that a pump-generated voltage is generated, both switching transistors Q1 and Q2 are turned off. That is, by controlling the switching state and duty cycle of Q1 and Q2, the reverse flow of pump-generated voltage energy is prevented.

[0077] See Figure 4 A control device for preventing pump-generated voltage backflow based on a synchronous BUCK circuit, provided in an embodiment of the present invention, includes:

[0078] The constant voltage control module 400 is used to perform switching control of the synchronous BUCK circuit according to the set frequency and duty cycle of the switching transistor, and records the values ​​of Vo and Vin once in each switching control cycle;

[0079] The data reading module 410 is used to read the values ​​of Vo and Vin recorded in each switch control cycle within the predetermined judgment period when the predetermined judgment period is reached, wherein the judgment period is longer than the switch control cycle.

[0080] The pump voltage determination module 420 is used to determine whether a pump voltage is generated by using the changes in the values ​​of Vo and Vin recorded in each switch control cycle within the judgment period. If it is determined that a pump voltage is generated, it returns to the reverse current control module 430; if it is determined that no pump voltage is generated, it returns to the constant voltage control module 410.

[0081] The reverse flow control module 430 is used to turn off both switching transistors Q1 and Q2.

[0082] Optional, the pump-up voltage determination module 420 is specifically used for

[0083] Calculate the average value of Vin recorded within the judgment period, Vinavg, and determine whether the calculated average value Vinavg is greater than the preset threshold Vinavgcs.

[0084] If the average value Vinavg is greater than the preset threshold Vinavgcs, calculate the first average value Voavg of Vo recorded within the judgment period; calculate the first difference ΔVoavg between the average value of Vo recorded in the second half of the judgment period and the average value of Vo recorded in the first half of the judgment period; calculate the difference ΔVinavg between the average value of Vin recorded in the second half of the judgment period and the average value of Vin recorded in the first half of the judgment period.

[0085] Determine whether the first average value Voavg is greater than the preset threshold Voavgcs, whether the first difference ΔVoavg is greater than the preset threshold ΔVoavgcs, and whether the difference ΔVinavg is greater than the preset threshold ΔVinavgcs;

[0086] If the first average value Voavg is greater than the preset threshold Voavgcs, the first difference ΔVoavg is greater than the preset threshold ΔVoavgcs, and the difference ΔVinavg is greater than the preset threshold ΔVinavgcs, then a pumping voltage is determined to be generated.

[0087] Optionally, the preset threshold Vinavgcs is the maximum allowable input voltage of the synchronous BUCK circuit plus a fixed value; the preset threshold Voavgcs is 101% of the target value of the output voltage of the synchronous BUCK circuit; the preset threshold ΔVoavgcs is 0; the preset threshold ΔVinavgcs is 0.

[0088] Optional, also includes:

[0089] The data recording module 440 is used to record the value of Vo according to the switching control cycle after both switching transistors Q1 and Q2 are turned off, and to read the value of Vo recorded in each switching control cycle within the judgment cycle when the predetermined judgment cycle is reached.

[0090] The data calculation module 450 is used to calculate the second average value Voavg of the Vo values ​​recorded within the judgment period, and to calculate the second difference ΔVoavg between the average value of Vo recorded within the second half of the judgment period and the average value of Vo recorded within the first half of the judgment period.

[0091] The data judgment module 460 is used to determine whether the second average value Voavg is less than the preset threshold Voavgcs and whether the second difference ΔVoavg is less than the preset threshold ΔVoavgcs; if the second average value Voavg is less than the preset threshold Voavgcs and the second difference ΔVoavg is less than the preset threshold ΔVoavgcs, it returns to the constant voltage control module 400; otherwise, it returns to the reverse current control module 430.

[0092] Optional, also includes:

[0093] The duty cycle determination module is used to determine the duty cycle D of the switching transistor Q2. Q2 At the same time, determine the duty cycle D. Q2 Is it less than the preset threshold D? Q2max ;

[0094] At duty cycle D Q2 Not less than the preset threshold D Q2max In this case, the pump-generated voltage is determined, and thus both switching transistors Q1 and Q2 are turned off; where D Q2max The following conditions must be met:

[0095] (1 - D) Q2max ) < (Vor / Vinrmax)

[0096] Where Vor is the target output voltage of the synchronous BUCK circuit, and Vinrmax is the rated maximum input voltage of the synchronous BUCK circuit.

[0097] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A control method for preventing pump-generated voltage backflow based on a synchronous BUCK circuit, characterized in that, include: The synchronous BUCK circuit performs switching control according to the set frequency and duty cycle of the switching transistor, and records the values ​​of Vo and Vin once in each switching control cycle; When the predetermined judgment period is reached, the values ​​of Vo and Vin recorded in each switch control cycle within the judgment period are read, where the judgment period is longer than the switch control cycle. The change in the values ​​of Vo and Vin recorded in each switch control cycle within the judgment period is used to determine whether pump-generated voltage is generated. If so, turn off both switching transistors Q1 and Q2; If not, return to the step of executing the switching control of the synchronous BUCK circuit according to the set frequency and duty cycle of the switching transistor, and recording the values ​​of Vo and Vin once for each switching control cycle; The steps for determining whether pump-generated voltage is generated by using the changes in Vo and Vin values ​​recorded in each switch control cycle within the read judgment period include: Calculate the average value of Vin recorded within the judgment period, Vinavg, and determine whether the calculated average value Vinavg is greater than the preset threshold Vinavgcs. If the average value Vinavg is greater than the preset threshold Vinavgcs, calculate the first average value Voavg of Vo recorded within the judgment period; calculate the first difference ΔVoavg between the average value of Vo recorded in the second half of the judgment period and the average value of Vo recorded in the first half of the judgment period; calculate the difference ΔVinavg between the average value of Vin recorded in the second half of the judgment period and the average value of Vin recorded in the first half of the judgment period. Determine whether the first average value Voavg is greater than the preset threshold Voavgcs, whether the first difference ΔVoavg is greater than the preset threshold ΔVoavgcs, and whether the difference ΔVinavg is greater than the preset threshold ΔVinavgcs; If the first average value Voavg is greater than the preset threshold Voavgcs, the first difference ΔVoavg is greater than the preset threshold ΔVoavgcs, and the difference ΔVinavg is greater than the preset threshold ΔVinavgcs, then the pumping voltage is determined to be generated.

2. The control method for preventing pump-generated voltage backflow based on a synchronous BUCK circuit as described in claim 1, characterized in that, The preset threshold Vinavgcs is the maximum allowable input voltage of the synchronous BUCK circuit plus a fixed value; The preset threshold Voavgcs is 101% of the target value of the output voltage of the synchronous BUCK circuit; The preset threshold ΔVoavgcs is 0; The preset threshold ΔVinavgcs is 0.

3. The control method for preventing pump-generated voltage backflow based on a synchronous BUCK circuit as described in claim 1, characterized in that, After turning off both switching transistors Q1 and Q2, the following steps are also included: Record the value of Vo according to the switching control cycle, and when the predetermined judgment cycle is reached, read the value of Vo recorded in each switching control cycle within the judgment cycle; Calculate the second average value of Vo recorded within the judgment period, Voavg, and calculate the second difference ΔVoavg between the average value of Vo recorded in the second half of the judgment period and the average value of Vo recorded in the first half of the judgment period. Determine whether the second average value Voavg is less than the preset threshold Voavgcs and whether the second difference ΔVoavg is less than the preset threshold ΔVoavgcs; If the second average value Voavg is less than the preset threshold Voavgcs and the second difference ΔVoavg is less than the preset threshold ΔVoavgcs, the process of returning to the synchronous BUCK circuit switching control according to the set frequency and duty cycle of the switching transistors, and recording the values ​​of Vo and Vin once in each switching control cycle, otherwise the switching transistors Q1 and Q2 remain off.

4. The control method for preventing pump-generated voltage backflow based on a synchronous BUCK circuit as described in claim 1, characterized in that, The control method further includes: Determine the duty cycle D of switch Q2 Q2 At the same time, determine the duty cycle D. Q2 Is it less than the preset threshold D? Q2max ; At duty cycle D Q2 Not less than the preset threshold D Q2max In this case, the pump-generated voltage is determined, and thus both switching transistors Q1 and Q2 are turned off; where D Q2max The following conditions must be met: (1 - D Q2max (Vor / Vinrmax) Where Vor is the target output voltage of the synchronous BUCK circuit, and Vinrmax is the rated maximum input voltage of the synchronous BUCK circuit.

5. A control device for preventing pump-generated voltage backflow based on a synchronous BUCK circuit, characterized in that, include: The constant voltage control module is used to execute the switching control of the synchronous BUCK circuit according to the set frequency and duty cycle of the switching transistor, and records the values ​​of Vo and Vin once in each switching control cycle; The data reading module is used to read the Vo and Vin values ​​recorded in each switch control cycle within the predetermined judgment period when the judgment period is reached, where the judgment period is longer than the switch control cycle. The pump-up voltage determination module is used to determine whether pump-up voltage is generated by using the changes in the values ​​of Vo and Vin recorded in each switch control cycle within the judgment period. If it is determined that pump-up voltage is generated, it returns to the reverse current control module; if it is determined that pump-up voltage is not generated, it returns to the constant voltage control module. The reverse current control module is used to turn off both switching transistors Q1 and Q2; Pump boost voltage determination module, specifically used for Calculate the average value of Vin recorded within the judgment period, Vinavg, and determine whether the calculated average value Vinavg is greater than the preset threshold Vinavgcs. If the average value Vinavg is greater than the preset threshold Vinavgcs, calculate the first average value Voavg of Vo recorded within the judgment period; Calculate the first difference ΔVoavg between the average value of Vo recorded in the second half of the judgment period and the average value of Vo recorded in the first half of the judgment period; calculate the difference ΔVinavg between the average value of Vin recorded in the second half of the judgment period and the average value of Vin recorded in the first half of the judgment period. Determine whether the first average value Voavg is greater than the preset threshold Voavgcs, whether the first difference ΔVoavg is greater than the preset threshold ΔVoavgcs, and whether the difference ΔVinavg is greater than the preset threshold ΔVinavgcs; If the first average value Voavg is greater than the preset threshold Voavgcs, the first difference ΔVoavg is greater than the preset threshold ΔVoavgcs, and the difference ΔVinavg is greater than the preset threshold ΔVinavgcs, then the pumping voltage is determined to be generated.

6. The control device for preventing pump-generated voltage backflow based on a synchronous BUCK circuit as described in claim 5, characterized in that, The preset threshold Vinavgcs is the maximum allowable input voltage of the synchronous BUCK circuit plus a fixed value; The preset threshold Voavgcs is 101% of the target value of the output voltage of the synchronous BUCK circuit; The preset threshold ΔVoavgcs is 0; The preset threshold ΔVinavgcs is 0.

7. The control device for preventing pump-generated voltage backflow based on a synchronous BUCK circuit as described in claim 5, characterized in that, Also includes: The data recording module is used to record the value of Vo according to the switching control cycle after both switching transistors Q1 and Q2 are turned off, and to read the value of Vo recorded in each switching control cycle within the judgment period when the predetermined judgment period is reached. The data calculation module is used to calculate the second average value Voavg of the Vo values ​​recorded within the judgment period, and to calculate the second difference ΔVoavg between the average value of Vo recorded within the second half of the judgment period and the average value of Vo recorded within the first half of the judgment period. The data judgment module is used to determine whether the second average value Voavg is less than the preset threshold Voavgcs and whether the second difference ΔVoavg is less than the preset threshold ΔVoavgcs. If the second average value Voavg is less than the preset threshold Voavgcs and the second difference ΔVoavg is less than the preset threshold ΔVoavgcs, return to the constant voltage control module; otherwise, return to the reverse current control module.

8. The control device for preventing pump-generated voltage backflow based on a synchronous BUCK circuit as described in claim 5, characterized in that, Also includes: The duty cycle determination module is used to determine the duty cycle D of the switching transistor Q2. Q2 At the same time, determine the duty cycle D. Q2 Is it less than the preset threshold D? Q2max ; At duty cycle D Q2 Not less than the preset threshold D Q2max In this case, the pump-generated voltage is determined, and thus both switching transistors Q1 and Q2 are turned off; where D Q2max The following conditions must be met: (1 - D Q2max ) < (Vor / Vinrmax) Where Vor is the target output voltage of the synchronous BUCK circuit, and Vinrmax is the rated maximum input voltage of the synchronous BUCK circuit.

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