Control method of direct current converter, control terminal and storage medium

Abstract

The application provides a control method of a direct current converter, a control terminal and a storage medium. The direct current converter comprises a flying capacitor, a first switch tube, a second switch tube, a third switch tube and a fourth switch tube. The method comprises the following steps: obtaining the working state of a battery; when it is detected that the working state of the battery is an abnormal state, obtaining the voltage of the flying capacitor, and controlling the action of each switch tube of the direct current converter according to the voltage of the flying capacitor and the working state of the battery, so as to charge or discharge the flying capacitor, and make the voltage of the flying capacitor in a preset range; wherein the abnormal state comprises a forbidden charging state and a forbidden discharging state. When the battery part switch tube is blocked, the voltage of the flying capacitor is always maintained at a normal voltage by controlling the action of each switch tube, and when the battery returns to normal, the normal working of the direct current converter is not affected, and the stability of the direct current converter is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power supply, and in particular to a control method of a direct current converter, a control terminal and a storage medium. BACKGROUND

[0002] At present, the application demand of high-power battery charging and discharging becomes more, and using three-phase electricity to charge the battery and using high-voltage battery energy storage becomes a better solution. For example, for a photovoltaic energy storage system, a direct current converter and an inverter can be used to realize the grid-connected charging and discharging of the battery. The direct current converter realizes the conversion between the battery voltage and the direct current bus voltage through the on-off control of the switching tube.

[0003] In the prior art, when the battery is forbidden to charge or discharge due to some reasons, the switching tube is blocked, and all the switching tubes are disconnected, so that the voltage of the flying capacitor cannot be maintained. When the battery returns to normal, the flying capacitor cannot be charged, which affects the normal work of the direct current converter. SUMMARY

[0004] The embodiments of the present application provide a control method of a direct current converter, a control terminal and a storage medium to solve the problem that the voltage of the flying capacitor cannot be maintained when the battery is forbidden to charge or discharge in the prior art, which affects the normal work of the direct current converter.

[0005] In the first aspect, the embodiments of the present application provide a control method of a direct current converter, the direct current converter comprising: a flying capacitor, a first switching tube, a second switching tube, a third switching tube and a fourth switching tube; the first end of the first switching tube is connected with the positive electrode of a battery and the first end of the third switching tube respectively, and the second end of the first switching tube is connected with the negative electrode of the battery and the negative direct current bus through the second switching tube; the second end of the third switching tube is connected with the positive direct current bus through the fourth switching tube; and the flying capacitor is connected between the second end of the first switching tube and the second end of the third switching tube.

[0006] The above method comprises:

[0007] obtaining the working state of the battery;

[0008] when it is detected that the working state of the battery is an abnormal state, obtaining the voltage of the flying capacitor, and controlling the action of each switching tube of the direct current converter according to the voltage of the flying capacitor and the working state of the battery, so as to charge or discharge the flying capacitor, so that the voltage of the flying capacitor is within a preset range;

[0009] The abnormal state includes a forbidden charging state and a forbidden discharging state.

[0010] In a second aspect, an embodiment of the present application provides a control terminal, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, the steps of the control method of the direct current converter according to the first aspect or any possible implementation manner of the first aspect are implemented.

[0011] In a third aspect, an embodiment of the present application provides a computer readable storage medium, which stores a computer program, and when the computer program is executed by a processor, the steps of the control method of the direct current converter according to the first aspect or any possible implementation manner of the first aspect are implemented.

[0012] The embodiment of the present application provides a control method of a direct current converter, a control terminal and a storage medium. The direct current converter comprises a flying capacitor, a first switch tube, a second switch tube, a third switch tube and a fourth switch tube. The first end of the first switch tube is connected with the positive pole of a battery and the first end of the third switch tube, respectively. The second end of the first switch tube is connected with the negative pole of the battery and the negative direct current bus through the second switch tube, respectively. The second end of the third switch tube is connected with the positive direct current bus through the fourth switch tube. The flying capacitor is connected between the second end of the first switch tube and the second end of the third switch tube. The method comprises the following steps: obtaining the working state of the battery; when it is detected that the working state of the battery is an abnormal state, obtaining the voltage of the flying capacitor, and controlling the action of each switch tube of the direct current converter according to the voltage of the flying capacitor and the working state of the battery, so as to charge or discharge the flying capacitor, and make the voltage of the flying capacitor in a preset range; wherein the abnormal state comprises a forbidden charging state and a forbidden discharging state. In the embodiment of the present application, when the battery is in an abnormal working state and part of the switch tubes are blocked, the voltage of the flying capacitor is always maintained at a normal voltage by controlling the action of the limited other switch tubes, so that the flying capacitor can work normally when the battery returns to normal, and the normal working of the direct current converter is not affected, and the stability of the direct current converter is improved. At the same time, the voltage of the flying capacitor is always maintained at a normal voltage, the voltage difference of the switch tubes will not be too large to damage the switch tubes, and the loss of the switch tubes can be effectively reduced. BRIEF DESCRIPTION OF DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0014] Figure 1 It is a circuit structure schematic diagram of a direct current converter provided by the embodiment of the present application.

[0015] Figure 2is an implementation flow chart of a control method of a direct current converter provided by an embodiment of the present application;

[0016] Figure 3 is a circuit structure schematic diagram of a direct current converter provided by another embodiment of the present application;

[0017] Figure 4 is Figure 3 a current path of the direct current converter shown in

[0018] Figure 5 is Figure 3 a second current path of the direct current converter shown in

[0019] Figure 6 is Figure 3 a third current path of the direct current converter shown in

[0020] Figure 7 is Figure 3 a fourth current path of the direct current converter shown in

[0021] Figure 8 is a schematic diagram of a control loop of a direct current converter provided by an embodiment of the present application;

[0022] Figure 9 is a circuit structure schematic diagram of a direct current converter provided by another embodiment of the present application;

[0023] Figure 10 is a structure schematic diagram of a control device of a direct current converter provided by an embodiment of the present application;

[0024] Figure 11 is a schematic diagram of a control terminal provided by an embodiment of the present application. DETAILED DESCRIPTION

[0025] In the following description, for the purpose of explanation and not limitation, specific details are set forth, such as particular system configurations, techniques, etc., in order to provide a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application can be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

[0026] In order to make the objects, technical solutions and advantages of the present application clearer, the following will be described with reference to the accompanying drawings by embodiments.

[0027] Referring to Figure 1As shown in the figure, the circuit structure of the direct current converter is shown, and the direct current converter comprises: a flying capacitor C1, a first switch Q1, a second switch Q2, a third switch Q3, and a fourth switch Q4; the first end of the first switch Q1 is connected with the positive pole of a battery Bat and the first end of the third switch Q3, respectively; the second end of the first switch Q1 is connected with the negative pole of the battery Bat and the negative direct current bus BUS- through the second switch Q2, respectively; the second end of the third switch Q3 is connected with the positive direct current bus BUS+ through the fourth switch Q4; the flying capacitor C1 is connected between the second end of the first switch Q1 and the second end of the third switch Q3;

[0028] Figure 2 The implementation flowchart of the control method of the direct current converter is shown. The above method comprises:

[0029] S101: obtaining the working state of the battery Bat;

[0030] S102: when detecting that the working state of the battery Bat is an abnormal state, obtaining the voltage of the flying capacitor C1, and according to the voltage of the flying capacitor C1 and the working state of the battery Bat, controlling the action of each switch of the direct current converter to charge or discharge the flying capacitor C1, so that the voltage of the flying capacitor C1 is within a preset range;

[0031] The abnormal state comprises: a forbidden charging state and a forbidden discharging state.

[0032] In the embodiment of the present application, when the working state of the battery Bat is in the forbidden charging or forbidden discharging state, the flying capacitor C1 is charged or discharged by controlling the action of each switch, so that the voltage of the flying capacitor C1 is always maintained within a preset range, ensuring that the flying capacitor C1 can normally charge and discharge when the battery Bat returns to normal, so that the direct current converter can work normally, and the stability of the direct current converter is improved. The voltage of the flying capacitor C1 is always maintained at a normal voltage, so that the voltage difference borne by the switch of the direct current converter will not exceed the maximum voltage difference of the switch, avoiding damage to the switch due to excessive voltage difference, and improving the safety of the direct current converter. At the same time, the loss of the switch can also be effectively reduced.

[0033] The preset range is determined based on the direct current bus voltage, for example, can be U BUS The direct current bus voltage is U, and Δu is the voltage allowed offset, so that the voltage of the flying capacitor C1 is stabilized at about

[0034] It should be noted that, with reference to Figure 1 The direct current converter further comprises a first inductor L1, a positive direct current bus capacitor C2, a negative direct current bus capacitor C3, a battery capacitor C4, and the like, which are well known in the art and will not be described in detail.​

[0035] In a possible implementation, with reference to Figure 3 , the direct current converter can further include: a first switch K1; the second end of the first switch tube Q1 is further connected with the bus midpoint through the first switch K1; S102 can include:

[0036] S1021: when the working state of the battery Bat is the forbidden charging state, the third switch tube Q3 and the fourth switch tube Q4 are controlled to be turned off, the first switch K1 is controlled to be turned off, and when the voltage of the flying capacitor C1 is greater than the flying capacitor voltage reference value, the first switch tube Q1 is controlled to be turned on and the second switch tube Q2 is controlled to be turned off; when the voltage of the flying capacitor C1 is not greater than the flying capacitor voltage reference value, the second switch tube Q2 is controlled to be turned on and the first switch tube Q1 is controlled to be turned off;

[0037] S1022: when the working state of the battery Bat is the forbidden discharging state, the first switch tube Q1 and the second switch tube Q2 are controlled to be turned off, the first switch K1 is controlled to be turned on, and when the voltage of the flying capacitor C1 is greater than the flying capacitor voltage reference value, the third switch tube Q3 is controlled to be turned on and the fourth switch tube Q4 is controlled to be turned off; when the voltage of the flying capacitor C1 is not greater than the flying capacitor voltage reference value, the fourth switch tube Q4 is controlled to be turned on and the third switch tube Q3 is controlled to be turned off;

[0038] The flying capacitor voltage reference value is in a preset range.

[0039] Corresponding to the direct current converter in Figure 2 , when the battery Bat is charged, the third switch tube Q3 and the fourth switch tube Q4 act to charge the battery Bat; when the battery Bat is discharged, the first switch tube Q1 and the second switch tube Q2 act to charge the direct current bus. When the working state of the battery Bat is the forbidden charging state, the third switch tube Q3 and the fourth switch tube Q4 are first controlled to be turned off, the driving of the third switch tube Q3 and the fourth switch tube Q4 is blocked, and the charging of the battery Bat is prohibited; at the same time, the first switch K1 is turned off, the flying capacitor C1 is charged and discharged through the on-off of the first switch tube Q1 and the second switch tube Q2, and the stability of the voltage of the flying capacitor C1 is realized.

[0040] Similarly, when the working state of the battery Bat is the forbidden discharging state, the first switch tube Q1 and the second switch tube Q2 are first controlled to be turned off, the driving of the first switch tube Q1 and the second switch tube Q2 is blocked, and the discharging of the battery Bat is prohibited; at the same time, the first switch K1 is closed, the flying capacitor C1 is charged and discharged through the on-off of the third switch tube Q3 and the fourth switch tube Q4, and the stability of the voltage of the flying capacitor C1 is realized.

[0041] For example, the flying capacitor voltage reference value can be

[0042] Corresponding to the above embodiment, in a possible implementation, when the working state of the battery Bat is the forbidden charging state, and the voltage of the flying capacitor C1 is not greater than the flying capacitor voltage reference value, the battery Bat charges the flying capacitor C1 through the body diode of the third switch tube Q3 and the second switch tube Q2;

[0043] When the working state of the battery Bat is the forbidden charging state, and the voltage of the flying capacitor C1 is greater than the flying capacitor voltage reference value, the flying capacitor C1 is discharged through the body diode of the first switch tube Q1 and the fourth switch tube Q4;

[0044] When the working state of the battery Bat is the forbidden discharging state, and the voltage of the flying capacitor C1 is greater than the flying capacitor voltage reference value, the flying capacitor C1 is discharged through the body diode of the second switch tube Q2 and the third switch tube Q3;

[0045] When the working state of the battery Bat is the forbidden discharging state, and the voltage of the flying capacitor C1 is not greater than the flying capacitor voltage reference value, the flying capacitor C1 is charged through the fourth switch tube Q4 and the first switch K1.

[0046] Specifically, when the working state of the battery Bat is the forbidden charging state, the third switch tube Q3 and the fourth switch tube Q4 are controlled to be turned off, the battery Bat charging path is cut off, and the first switch K1 is also turned off; when the voltage of the flying capacitor C1 is greater than the flying capacitor voltage reference value, the first switch tube Q1 is controlled to be turned on, the current path shown in the figure is formed, the flying capacitor C1 is discharged through the body diode of the first switch tube Q1 and the fourth switch tube Q4, and the voltage of the flying capacitor C1 is reduced; Figure 4 When the voltage of the flying capacitor C1 is less than the flying capacitor voltage reference value, the current path shown in the figure is formed, the battery Bat charges the flying capacitor C1 through the body diode of the third switch tube Q3 and the second switch tube Q2, and the voltage of the flying capacitor C1 is increased. Figure 5 When the working state of the battery Bat is the forbidden charging state, the third switch tube Q3 and the fourth switch tube Q4 are controlled to be turned off, the battery Bat charging path is cut off, and the first switch K1 is also turned off; when the voltage of the flying capacitor C1 is greater than the flying capacitor voltage reference value, the first switch tube Q1 is controlled to be turned on, the current path shown in the figure is formed, the flying capacitor C1 is discharged through the body diode of the first switch tube Q1 and the fourth switch tube Q4, and the voltage of the flying capacitor C1 is reduced; When the voltage of the flying capacitor C1 is less than the flying capacitor voltage reference value, the current path shown in the figure is formed, the battery Bat charges the flying capacitor C1 through the body diode of the third switch tube Q3 and the second switch tube Q2, and the voltage of the flying capacitor C1 is increased.

[0047] When the working state of the battery Bat is the forbidden discharging state, the first switch tube Q1 and the second switch tube Q2 are controlled to be turned off, the battery Bat discharging path is cut off, and the first switch K1 is closed; when the voltage of the flying capacitor C1 is greater than the flying capacitor voltage reference value, the third switch tube Q3 is controlled to be turned on, the current path shown in the figure is formed, the flying capacitor C1 is discharged through the body diode of the third switch tube Q3 and the second switch tube Q2, and the voltage of the flying capacitor C1 is reduced; Figure 6 When the voltage of the flying capacitor C1 is less than the flying capacitor voltage reference value, the current path shown in the figure is formed, the battery Bat charges the flying capacitor C1 through the body diode of the third switch tube Q3 and the second switch tube Q2, and the voltage of the flying capacitor C1 is increased. Figure 7 When the working state of the battery Bat is the forbidden charging state, the third switch tube Q3 and the fourth switch tube Q4 are controlled to be turned off, the battery Bat charging path is cut off, and the first switch K1 is also turned off; when the voltage of the flying capacitor C1 is greater than the flying capacitor voltage reference value, the first switch tube Q1 is controlled to be turned on, the current path shown in the figure is formed, the flying capacitor C1 is discharged through the body diode of the first switch tube Q1 and the fourth switch tube Q4, and the voltage of the flying capacitor C1 is reduced;

[0048] In a possible implementation, reference is made to Figure 8The switch tube of the direct current converter can be controlled by a control loop; the control loop can comprise: a charge-discharge control loop, a flying capacitor voltage loop, a boost voltage loop, and a buck voltage loop;

[0049] The charge-discharge control loop obtains the voltage of the direct current bus and the voltage of the battery Bat, and outputs a first loop given value based on the voltage of the direct current bus and the voltage of the battery Bat;

[0050] The flying capacitor voltage loop obtains the voltage of the flying capacitor C1, and outputs a second loop given value based on the voltage of the flying capacitor C1;

[0051] The boost voltage loop obtains the first loop given value and the second loop given value, and outputs a first switch control signal and a second switch control signal based on the first loop given value and the second loop given value; wherein the first switch control signal is used for controlling the first switch tube Q1, and the second switch control signal is used for controlling the second switch tube Q2;

[0052] The buck voltage loop obtains the first loop given value and the second loop given value, and outputs a third switch control signal and a fourth switch control signal based on the first loop given value and the second loop given value; wherein the third switch control signal is used for controlling the third switch tube Q3, and the fourth switch control signal is used for controlling the fourth switch tube Q4.

[0053] Corresponding to the above embodiment, the charge-discharge control loop, the flying capacitor voltage loop, the boost voltage loop, and the buck voltage loop are arranged, and the control of each switch tube is realized through the loop. The flying capacitor voltage loop detects the voltage of the flying capacitor C1, and generates the second loop given value according to the voltage of the flying capacitor C1; the boost voltage loop and the buck voltage loop control each switch tube according to the second loop given value, and realize the control of the voltage of the flying capacitor C1.

[0054] Exemplarily, in a possible implementation, with reference to Figure 8 For the boost voltage loop, the first loop given value is input into a first limiter to obtain a first preprocessed signal; the difference between the first preprocessed signal and the second loop given value is input into a second limiter to obtain the first switch control signal; and the sum of the first preprocessed signal and the second loop given value is input into a third limiter to obtain the second switch control signal; wherein the minimum limiting value of the second limiter and the third limiter is 0;

[0055] For the buck voltage loop, the first loop given value is input into a fourth limiter and a first inverter to obtain a second preprocessed signal; the difference between the second preprocessed signal and the second loop given value is input into a fifth limiter to obtain the third switch control signal; and the sum of the second preprocessed signal and the second loop given value is input into a sixth limiter to obtain the fourth switch control signal; wherein the minimum limiting value of the fifth limiter and the sixth limiter is 0;

[0056] When the working state of the battery Bat is the forbidden charging state, the first pretreatment signal is 0; when the working state of the battery Bat is the forbidden discharging state, the second pretreatment signal is 0.

[0057] In a possible implementation, the minimum clipping values of the first clipper and the second clipper are both 0.

[0058] In another possible implementation, the reference Figure 8 For the flying capacitor voltage loop, the difference between the voltage of the flying capacitor C1 and the flying capacitor voltage reference value is input into the first PI controller to obtain a second loop given value.

[0059] When the voltage of the flying capacitor C1 is greater than the flying capacitor voltage reference value, the second loop given value is negative; otherwise, the second loop given value is positive.

[0060] In another possible implementation, the reference Figure 8 For the charging and discharging control loop, the difference between the DC bus voltage and the bus voltage reference value is input into the second PI controller to obtain a first current reference value; the difference between the voltage of the battery Bat and the battery voltage reference value is input into the third PI controller to obtain a second current reference value through the second inverter. The difference between the larger one of the first current reference value and the second current reference value and a current sampling value is input into the fourth PI controller to obtain a first loop given value.

[0061] For example, the reference Figure 8 When the working state of the battery Bat is the forbidden discharging state and the voltage of the battery Bat is low, the second reference current is negative, the first reference current is positive, and the first loop given value is also positive; the first loop given value is input into the step-down loop, is negative after the first inverter, and is 0 after the fourth clipper. When the voltage of the flying capacitor C1 is greater than the flying capacitor voltage reference value, the second loop given value is negative, the third control signal is positive, the fourth control signal is 0, the fourth switch Q4 is turned off, and the third switch Q3 is turned on. When the voltage of the flying capacitor C1 is not greater than the flying capacitor voltage reference value, the second loop given value is positive, the third control signal is 0, the fourth control signal is positive, the fourth switch Q4 is turned on, and the third switch Q3 is turned off. Since the first switch Q1 and the second switch Q2 are forced to be clamped when the working state of the battery Bat is the forbidden discharging state, the output of the step-up loop is not considered.

[0062] Similarly, when the working state of the battery Bat is forbidden charging, the first loop is given negative, the first loop is given input boost ring, and after the first limiter, it is 0; when the voltage of the flying capacitor C1 is greater than the flying capacitor voltage reference value, the second loop is given negative, then the first control signal is positive, the second control signal is 0, the first switch tube Q1 is turned on, and the second switch tube Q2 is turned off. When the voltage of the flying capacitor C1 is not greater than the flying capacitor voltage reference value, the second loop is given positive, the first switch control signal is 0, the second switch control signal is positive, the first switch tube Q1 is turned off, and the second switch tube Q2 is turned on. Since the working state of the battery Bat is forbidden charging, the third switch tube Q3 and the fourth switch tube Q4 are forced to be blocked, so the output of the buck ring is not considered.

[0063] In a possible implementation, the method can further include:

[0064] S103: when it is detected that the working state of the battery Bat is a normal state, the first switch K1 is controlled to be turned off, and each switch tube of the direct current converter is controlled to act according to a target control parameter, so as to charge or discharge the battery Bat;

[0065] The normal state includes a charging state and a discharging state.

[0066] In a possible implementation, S103 can include:

[0067] S1031: when the working state of the battery Bat is the charging state, the first switch K1 is controlled to be turned off, and the third switch tube Q3 and the fourth switch tube Q4 are controlled to be turned on according to a first preset duty cycle;

[0068] S1032: when the working state of the battery Bat is the discharging state, the first switch K1 is controlled to be turned off, and the first switch tube Q1 and the second switch tube Q2 are controlled to be turned on according to a second preset duty cycle.

[0069] In the embodiment of the application, in the normal working state, for example, in the discharging state, the first switch tube Q1 and the second switch tube Q2 are alternately turned on to form a boost circuit, and the battery Bat is discharged to charge the direct current bus. Similarly, in the charging state, the third switch tube Q3 and the fourth switch tube Q4 are alternately turned on to form a buck circuit, and the direct current bus is bucked to charge the battery Bat.

[0070] In a possible implementation, with reference to Figure 9 The direct current converter can further include a diode D1.

[0071] The second end of the first switch tube Q1 is connected to the bus midpoint through the first switch K1 and the diode D1.

[0072] In a possible implementation, with reference to Figure 9The direct current converter can further include a first resistor R1.

[0073] The second end of the first switch tube Q1 is connected to the bus midpoint through the first switch K1, the first resistor R1 and a diode D1.

[0074] Reference Figure 9 The direct current converter can further include a diode D1 to ensure one-way conduction, and the first resistor R1 is used for current limiting.

[0075] It should be understood that the size of the serial number of each step in the above embodiment does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiment of the application.

[0076] The following is the device embodiment of the application, and for the details not described in detail, reference can be made to the corresponding method embodiments described above.

[0077] Figure 10 The structure schematic diagram of the control device of the direct current converter provided by the embodiment of the application is shown, and the direct current converter includes: a flying capacitor C1, a first switch tube Q1, a second switch tube Q2, a third switch tube Q3 and a fourth switch tube Q4. The first end of the first switch tube Q1 is connected to the positive electrode of a battery Bat and the first end of the third switch tube Q3, respectively. The second end of the first switch tube Q1 is connected to the negative electrode of the battery Bat and the negative direct current bus BUS- through the second switch tube Q2, respectively. The second end of the third switch tube Q3 is connected to the positive direct current bus BUS+ through the fourth switch tube Q4. The flying capacitor C1 is connected between the second end of the first switch tube Q1 and the second end of the third switch tube Q3. For the convenience of description, only the parts related to the embodiment of the application are shown, and the details are as follows:

[0078] As shown in Figure 10 The control device of the direct current converter includes:

[0079] The parameter acquisition module 21 is configured to acquire the working state of the battery Bat.

[0080] The flying capacitor control module 22 is configured to, when detecting that the working state of the battery Bat is an abnormal state, acquire the voltage of the flying capacitor C1, and control the action of each switch tube of the direct current converter according to the voltage of the flying capacitor C1 and the working state of the battery Bat, so as to charge or discharge the flying capacitor C1, so that the voltage of the flying capacitor C1 is within a preset range.

[0081] The abnormal state includes a forbidden charging state and a forbidden discharging state.

[0082] In a possible implementation, the direct current converter further comprises: a first switch K1; the second end of the first switch tube Q1 is further connected to the bus midpoint through the first switch K1; the flying capacitor control module 22 can comprise:

[0083] The forbidden charging control unit is configured to: when the working state of the battery Bat is the forbidden charging state, control the third switch tube Q3 and the fourth switch tube Q4 to be turned off, control the first switch K1 to be turned off, and when the voltage of the flying capacitor C1 is greater than a flying capacitor voltage reference value, control the first switch tube Q1 to be turned on and the second switch tube Q2 to be turned off; and when the voltage of the flying capacitor C1 is not greater than the flying capacitor voltage reference value, control the second switch tube Q2 to be turned on and the first switch tube Q1 to be turned off.

[0084] The forbidden discharging control unit is configured to: when the working state of the battery Bat is the forbidden discharging state, control the first switch tube Q1 and the second switch tube Q2 to be turned off, control the first switch K1 to be turned on, and when the voltage of the flying capacitor C1 is greater than the flying capacitor voltage reference value, control the third switch tube Q3 to be turned on and the fourth switch tube Q4 to be turned off; and when the voltage of the flying capacitor C1 is not greater than the flying capacitor voltage reference value, control the fourth switch tube Q4 to be turned on and the third switch tube Q3 to be turned off.

[0085] The flying capacitor voltage reference value is in a preset range.

[0086] In a possible implementation, when the working state of the battery Bat is the forbidden charging state and the voltage of the flying capacitor C1 is not greater than the flying capacitor voltage reference value, the battery Bat charges the flying capacitor C1 through the body diode of the third switch tube Q3 and the second switch tube Q2.

[0087] When the working state of the battery Bat is the forbidden charging state and the voltage of the flying capacitor C1 is greater than the flying capacitor voltage reference value, the flying capacitor C1 is discharged through the body diode of the first switch tube Q1 and the fourth switch tube Q4.

[0088] When the working state of the battery Bat is the forbidden discharging state and the voltage of the flying capacitor C1 is greater than the flying capacitor voltage reference value, the flying capacitor C1 is discharged through the body diode of the second switch tube Q2 and the third switch tube Q3.

[0089] When the working state of the battery Bat is the forbidden discharging state and the voltage of the flying capacitor C1 is not greater than the flying capacitor voltage reference value, the flying capacitor C1 is charged through the fourth switch tube Q4 and the first switch K1.

[0090] In a possible implementation, the switch tubes of the direct current converter are controlled by a control loop; the control loop comprises: a charging and discharging control loop, a flying capacitor voltage loop, a boost voltage loop, and a buck voltage loop.

[0091] The charge-discharge control loop obtains the DC bus voltage and the voltage of the battery Bat, and outputs a first loop given value based on the DC bus voltage and the voltage of the battery Bat;

[0092] The flying capacitor voltage loop obtains the voltage of the flying capacitor C1, and outputs a second loop given value based on the voltage of the flying capacitor C1;

[0093] The boost loop obtains the first loop given value and the second loop given value, and outputs a first switch control signal and a second switch control signal based on the first loop given value and the second loop given value; wherein the first switch control signal is used to control the first switch Q1, and the second switch control signal is used to control the second switch Q2;

[0094] The boost loop obtains the first loop given value and the second loop given value, and outputs a first switch control signal and a second switch control signal based on the first loop given value and the second loop given value; wherein the first switch control signal is used to control the first switch Q1, and the second switch control signal is used to control the second switch Q2;

[0095] In a possible implementation, the apparatus can further include:

[0096] The charge-discharge control module is configured to, when detecting that the working state of the battery Bat is a normal state, control the first switch K1 to be disconnected, and control the respective switch tubes of the DC converter to act according to a target control parameter, so as to charge or discharge the battery Bat;

[0097] The normal state includes a charging state and a discharging state.

[0098] In a possible implementation, the charge-discharge control module can include:

[0099] The charging control unit is configured to, when the working state of the battery Bat is the charging state, control the first switch K1 to be disconnected, and control the third switch tube Q3 and the fourth switch tube Q4 to be turned on according to a first preset duty cycle;

[0100] The discharging control unit is configured to, when the working state of the battery Bat is the discharging state, control the first switch K1 to be disconnected, and control the first switch tube Q1 and the second switch tube Q2 to be turned on according to a second preset duty cycle.

[0101] In a possible implementation, the DC converter can further include a diode D1.

[0102] The second end of the first switch tube Q1 is connected to the bus midpoint through the first switch K1 and the diode D1.

[0103] In a possible implementation, the DC converter can further include a first resistor R1.

[0104] The second terminal of the first switching transistor Q1 is connected to the midpoint of the busbar through the first switch K1, the first resistor R1, and the diode D1.

[0105] Figure 11 This is a schematic diagram of the terminal device 3 provided in an embodiment of the present invention. Figure 11 As shown, the terminal device 3 in this embodiment includes a processor 30 and a memory 31. The memory 31 is used to store a computer program 32, and the processor 30 is used to call and run the computer program 32 stored in the memory 31 to execute the steps in the control method embodiments of the various DC-DC converters described above, for example... Figure 2 The steps S101 to S102 are shown. Alternatively, the processor 30 is used to call and run the computer program 32 stored in the memory 31 to implement the functions of each module / unit in the above-described device embodiments, for example... Figure 10 The functions of modules 21 and 22 shown.

[0106] For example, computer program 32 can be divided into one or more modules / units, one or more of which are stored in memory 31 and executed by processor 30 to complete the present invention. One or more modules / units can be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of computer program 32 in terminal device 3. For example, computer program 32 can be divided into... Figure 10 Modules / units 21 to 22 are shown.

[0107] Terminal device 3 can be a computing device such as a desktop computer, laptop, handheld computer, or cloud server. Terminal device 3 may include, but is not limited to, processor 30 and memory 31. Those skilled in the art will understand that... Figure 11 This is merely an example of terminal device 3 and does not constitute a limitation on terminal device 3. It may include more or fewer components than shown, or combine certain components, or different components. For example, the terminal may also include input / output devices, network access devices, buses, etc.

[0108] The processor 30 can be a central processing unit (CPU), and can also be other general-purpose processors, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0109] The memory 31 can be an internal storage unit of the terminal device 3, such as a hard disk or a memory of the terminal device 3. The memory 31 can also be an external storage device of the terminal device 3, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the terminal device 3. Further, the memory 31 can also include both the internal storage unit and the external storage device of the terminal device 3. The memory 31 is used to store computer programs and other programs and data required by the terminal. The memory 31 can also be used to temporarily store data that has been output or will be output.

[0110] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above functional units and modules is exemplified, and in actual application, the above functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit, and the integrated unit can be realized in the form of hardware or in the form of software. In addition, the specific names of each functional unit and module are only for easy distinction, and do not limit the protection scope of the present application. The specific working process of the units and modules in the above system can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0111] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described or recorded in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0112] Those skilled in the art can understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0113] In the embodiments provided by the present application, it should be understood that the disclosed apparatus / terminal and method can be implemented in other ways. For example, the apparatus / terminal embodiments described above are merely schematic. For example, the division of the modules or units is merely a logical function division, and there can be another division manner in actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed coupling or direct coupling or communication connection between the units can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or in other forms.

[0114] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e. can be located in one place, or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiments.

[0115] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically independently, or two or more units can be integrated into one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0116] The integrated modules / units, if implemented in the form of software functional units and sold or used as independent products, can be stored in a computer readable storage medium. Based on such understanding, all or part of the processes in the above-mentioned embodiment methods can also be completed by a computer program instructing related hardware, and the computer program can be stored in a computer readable storage medium. When the computer program is executed by a processor, the steps of the above-mentioned various method embodiments can be implemented. The computer program includes computer program code, which can be in the form of source code, object code, executable files or some intermediate forms, etc. The computer readable medium can include any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0117] The above embodiments are only used to illustrate the technical solutions of the present application, but not limit it; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A control method of a direct current converter, characterized by, The direct current converter comprises a flying capacitor, a first switch tube, a second switch tube, a third switch tube and a fourth switch tube; a first end of the first switch tube is connected with a positive pole of a battery and a first end of the third switch tube respectively; a second end of the first switch tube is connected with a negative pole of the battery and a negative direct current bus through the second switch tube respectively; a second end of the third switch tube is connected with a positive direct current bus through the fourth switch tube; the flying capacitor is connected across the second end of the first switch tube and the second end of the third switch tube; The method comprises: acquiring the working state of the battery; when the working state of the battery is detected as an abnormal state, acquiring the voltage of the flying capacitor, and controlling the action of each switch tube of the direct current converter according to the voltage of the flying capacitor and the working state of the battery, so as to charge or discharge the flying capacitor, so that the voltage of the flying capacitor is within a preset range; wherein the abnormal state comprises a forbidden charging state and a forbidden discharging state; The direct current converter further comprises a first switch; the second end of the first switch tube is further connected with a bus midpoint through the first switch; the control of the action of each switch tube of the direct current converter according to the voltage of the flying capacitor and the working state of the battery comprises: when the working state of the battery is a forbidden charging state, the third switch tube and the fourth switch tube are controlled to be turned off, the first switch is controlled to be turned off, and when the voltage of the flying capacitor is greater than a flying capacitor voltage reference value, the first switch tube is controlled to be turned on and the second switch tube is controlled to be turned off; when the voltage of the flying capacitor is not greater than the flying capacitor voltage reference value, the second switch tube is controlled to be turned on and the first switch tube is controlled to be turned off; when the working state of the battery is a forbidden discharging state, the first switch tube and the second switch tube are controlled to be turned off, the first switch is controlled to be turned on, and when the voltage of the flying capacitor is greater than the flying capacitor voltage reference value, the third switch tube is controlled to be turned on and the fourth switch tube is controlled to be turned off; when the voltage of the flying capacitor is not greater than the flying capacitor voltage reference value, the fourth switch tube is controlled to be turned on and the third switch tube is controlled to be turned off; wherein the flying capacitor voltage reference value is within the preset range; The direct current converter further comprises a diode; the second end of the first switch tube is connected with the bus midpoint through the first switch and the diode.

2. The control method of a DC converter according to claim 1, characterized by, when the working state of the battery is a forbidden charging state and the voltage of the flying capacitor is not greater than the flying capacitor voltage reference value, the battery charges the flying capacitor through the body diode of the third switch tube and the second switch tube; when the working state of the battery is a forbidden charging state and the voltage of the flying capacitor is greater than the flying capacitor voltage reference value, the flying capacitor is discharged through the body diode of the first switch tube and the fourth switch tube; when the working state of the battery is a forbidden discharging state and the voltage of the flying capacitor is greater than the flying capacitor voltage reference value, the flying capacitor is discharged through the body diode of the second switch tube and the third switch tube; When the working state of the battery is a forbidden discharging state and the voltage of the flying capacitor is not greater than the flying capacitor voltage reference value, the fourth switch and the first switch are used to charge the flying capacitor.

3. The control method of a DC converter according to claim 1, characterized by, The switch of the direct current converter is controlled by a control loop; the control loop comprises a charging and discharging control loop, a flying capacitor voltage loop, a boost voltage loop and a buck voltage loop; The charging and discharging control loop obtains the voltage of the direct current bus and the voltage of the battery, and outputs a first loop given value based on the voltage of the direct current bus and the voltage of the battery; The flying capacitor voltage loop obtains the voltage of the flying capacitor, and outputs a second loop given value based on the voltage of the flying capacitor; The boost voltage loop obtains the first loop given value and the second loop given value, and outputs a first switch control signal and a second switch control signal based on the first loop given value and the second loop given value; wherein the first switch control signal is used to control the first switch, and the second switch control signal is used to control the second switch; The buck voltage loop obtains the first loop given value and the second loop given value, and outputs a third switch control signal and a fourth switch control signal based on the first loop given value and the second loop given value; wherein the third switch control signal is used to control the third switch, and the fourth switch control signal is used to control the fourth switch.

4. The control method of a DC converter according to claim 1 or 3, characterized by, The method further comprises: When it is detected that the working state of the battery is a normal state, the first switch is controlled to be turned off, and each switch of the direct current converter is controlled to act according to a target control parameter, so as to charge or discharge the battery; The normal state comprises a charging state and a discharging state.

5. The control method of a DC converter according to claim 4, characterized by, When it is detected that the working state of the battery is a normal state, the first switch is controlled to be turned off, and each switch of the direct current converter is controlled to act according to a target control parameter, so as to charge or discharge the battery, comprising: When the working state of the battery is a charging state, the first switch is controlled to be turned off, and the third switch and the fourth switch are controlled to be turned on according to a first preset duty ratio; When the working state of the battery is a discharging state, the first switch is controlled to be turned off, and the first switch and the second switch are controlled to be turned on according to a second preset duty ratio.

6. The control method of a DC converter according to claim 1, characterized by, The direct current converter further comprises a first resistor; The second end of the first switch is connected to the bus midpoint through the first switch, the first resistor and the diode.

7. A control terminal, characterized by comprising: The computer program is executed by the processor to implement the steps of the control method of the direct current converter according to any one of claims 1 to 6.

8. A computer-readable storage medium storing a computer program, the computer-readable storage medium comprising: The computer program is executed by the processor to implement the steps of the control method of the direct current converter according to any one of claims 1 to 6.

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