Control method and control device for a multi-phase boost-buck circuit

Abstract

The application provides a control method of a multi-phase buck-boost circuit, the circuit comprising a first multi-phase buck-boost module and a second multi-phase buck-boost module, both of which are connected with a first power supply and a second power supply and both of which comprise N buck-boost units connected in parallel, each of the buck-boost units comprising a first switch tube and a second switch tube; and the corresponding control method is that when the multi-phase buck-boost circuit is in a discharging mode, the second switch tubes of each buck-boost unit of the first multi-phase buck-boost module are controlled in staggered parallel connection, and the second switch tubes of each buck-boost unit of the second multi-phase buck-boost module are controlled in staggered parallel connection, so that the multi-phase buck-boost circuit works in a BOOST mode. The application can control the discharging process of the multi-phase buck-boost circuit, so that the application can be applied to a bidirectional charging pile system.

Description

Technical Field

[0001] This invention relates to the field of control technology for buck-boost circuits, and more particularly to a control method and control device for a multiphase buck-boost circuit. Background Technology

[0002] A bidirectional charging station system can include multiple bidirectional charging station modules. One end of each module is connected to the power grid, and the other end is used to connect to the electric vehicle's battery. The bidirectional charging station modules include DC-DC modules and DC-AC modules. The DC-DC module includes a buck-boost circuit.

[0003] Currently, buck-boost circuits typically use single-phase buck-boost circuits to boost and buck voltage. However, single-phase buck-boost circuits are limited by power constraints in terms of voltage stress, current stress, and response speed, and suffer from problems such as small voltage input range, low load capacity, and large ripple. Therefore, in bidirectional charging pile systems, multi-phase buck-boost circuits are used to boost and buck voltage. However, a control method for multi-phase buck-boost circuits that makes them suitable for bidirectional charging pile systems is lacking. Summary of the Invention

[0004] This invention provides a control method and control device for a multiphase step-up / step-down circuit to solve the problem that the prior art lacks a control method for a multiphase step-up / step-down circuit, making the multiphase step-up / step-down circuit applicable to bidirectional charging pile systems.

[0005] In a first aspect, embodiments of the present invention provide a control method for a multiphase buck-boost circuit. The multiphase buck-boost circuit includes a first multiphase buck-boost module and a second multiphase buck-boost module, both connected to a first power supply and a second power supply, and each including N buck-boost units connected in parallel. Each buck-boost unit includes a first switch and a second switch, where N ≥ 2. The control method for the multiphase buck-boost circuit includes: when the multiphase buck-boost circuit is in discharge mode, performing interleaved parallel control on the second switches of each buck-boost unit of the first multiphase buck-boost module, performing interleaved parallel control on the second switches of each buck-boost unit of the second multiphase buck-boost module, and not driving the first switches of each buck-boost unit of the first and second multiphase buck-boost modules, so that the multiphase buck-boost circuit operates in BOOST mode, and the first power supply discharges the second power supply.

[0006] In a second aspect, embodiments of the present invention provide a control device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the control method for a multiphase buck-boost circuit as described in the first aspect or any possible implementation thereof.

[0007] This invention provides a control method and control device for a multiphase buck-boost circuit. The multiphase buck-boost circuit includes a first multiphase buck-boost module and a second multiphase buck-boost module, both connected to a first power supply and a second power supply, and each including N buck-boost units connected in parallel. Each buck-boost unit includes a first switch and a second switch. The corresponding control method involves interleaving the second switches of each buck-boost unit in the first multiphase buck-boost module and interleaving the second switches of each buck-boost unit in the second multiphase buck-boost module when the multiphase buck-boost circuit is in discharge mode, thereby enabling the multiphase buck-boost circuit to operate in BOOST mode. This invention can control the discharge process of the multiphase buck-boost circuit, making it applicable to bidirectional charging pile systems. It can not only control the equalization of voltage and current in each phase but also achieve bus control, etc. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a flowchart illustrating the implementation of the control method for the multiphase buck-boost circuit provided in this embodiment of the invention.

[0010] Figure 2 This is a connection diagram of the multiphase buck-boost circuit provided in an embodiment of the present invention;

[0011] Figure 3 This is a schematic diagram of the multiphase buck-boost circuit provided in an embodiment of the present invention;

[0012] Figure 4 This is a schematic diagram of the Buck control loop in the charging mode provided in an embodiment of the present invention;

[0013] Figure 5 This is a schematic diagram of a Boost control loop under discharge mode provided in an embodiment of the present invention;

[0014] Figure 6 This is a schematic diagram of another Boost control loop in the discharge mode provided by an embodiment of the present invention;

[0015] Figure 7 This is a schematic diagram of the control device for the multiphase step-up / step-down circuit provided in an embodiment of the present invention;

[0016] Figure 8 This is a schematic diagram of the control device provided in an embodiment of the present invention. Detailed Implementation

[0017] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0018] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments will be described below in conjunction with the accompanying drawings.

[0019] See Figure 1 The diagram illustrates a flowchart of the control method for a multiphase buck-boost circuit provided in an embodiment of the present invention. The execution entity of the control method for the multiphase buck-boost circuit can be a control device, which can be a controller.

[0020] See Figure 2 and Figure 3 The aforementioned multiphase buck-boost circuit includes a first port, a second port, a third port, a first multiphase buck-boost module 21, and a second multiphase buck-boost module 22. The first port is used to connect to a first power supply, and the second and third ports are both used to connect to a second power supply. The first multiphase buck-boost module 21 is connected to the first port and the second port, respectively, and the second multiphase buck-boost module 22 is connected to the first port and the third port, respectively. When the multiphase buck-boost circuit is in charging mode, the second power supply charges the first power supply. When the multiphase buck-boost circuit is in discharging mode, the first power supply discharges to the second power supply.

[0021] See Figure 1 The control methods for the above-mentioned multiphase buck-boost circuit include:

[0022] In S101, when the multiphase buck-boost circuit is in charging mode, the multiphase buck-boost circuit is controlled to work in BUCK mode.

[0023] In S102, when the multiphase buck-boost circuit is in discharge mode, the multiphase buck-boost circuit is controlled to work in BOOST mode.

[0024] The BUCK module is the buck mode, and the BOOST mode is the boost mode.

[0025] In this embodiment, when the multi-phase buck-boost circuit is in charging mode, the second power supply charges the first power supply through the multi-phase buck-boost circuit. At this time, the multi-phase buck-boost circuit is controlled to operate in buck mode. When the multi-phase buck-boost circuit is in discharging mode, the first power supply charges the second power supply through the multi-phase buck-boost circuit. At this time, the multi-phase buck-boost circuit is controlled to operate in boost mode.

[0026] The first power source can be a DC power source, such as a battery. The second power source can be a DC power source, such as a battery, or an AC power source, such as the power grid. When the second power source is an AC power source, the second port is not directly connected to the AC power source, but can be connected to the second power source through a power conversion circuit, such as a bidirectional DC-AC conversion circuit.

[0027] This embodiment uses the above control method to control the multi-phase step-up / step-down circuit, enabling it to be applied to a bidirectional charging pile system.

[0028] In some embodiments, see Figure 3 The first port includes a first terminal BAT+ and a second terminal BAT-. The first terminal BAT+ is used to connect to the positive terminal of the first power supply, and the second terminal BAT- is used to connect to the negative terminal of the first power supply. The second port includes a third terminal A and a fourth terminal B. Both the first and second multiphase buck-boost modules include N buck-boost units connected in parallel, where N ≥ 2 and N is a positive integer. Each buck-boost unit includes a first switching transistor and a second switching transistor. The second end of the first switching transistor and the first end of the second switching transistor in each buck-boost unit are connected to the first terminal BAT+, and the second end of the second switching transistor in each buck-boost unit is connected to the second terminal BAT-. The first end of the first switching transistor in each buck-boost unit of the first multiphase buck-boost module is connected to the third terminal A. The first end of the first switching transistor in each buck-boost unit of the second multiphase buck-boost module is connected to the fourth terminal B.

[0029] The above S101 may include:

[0030] When the multiphase buck-boost circuit is in charging mode, the first switching transistors of each buck-boost unit of the first multiphase buck-boost module are interleaved and connected in parallel, and the first switching transistors of each buck-boost unit of the second multiphase buck-boost module are interleaved and connected in parallel, so that the multiphase buck-boost circuit works in BUCK mode.

[0031] The above S102 may include:

[0032] When the multiphase buck-boost circuit is in discharge mode, the second switching transistors of each buck-boost unit of the first multiphase buck-boost module are interleaved and connected in parallel, and the second switching transistors of each buck-boost unit of the second multiphase buck-boost module are interleaved and connected in parallel, so that the multiphase buck-boost circuit works in BOOST mode.

[0033] In this embodiment, each buck-boost unit can be regarded as a single-phase buck-boost circuit, and the multi-phase buck-boost circuit in this embodiment is a 2N-phase buck-boost circuit.

[0034] To enable the multiphase buck-boost circuit to operate in BUCK mode, the first switches of each buck-boost unit in the first multiphase buck-boost module and the second multiphase buck-boost module are interleaved and connected in parallel. In this mode, the second switches of each buck-boost unit in both modules are not driven. Similarly, to enable the multiphase buck-boost circuit to operate in BOOST mode, the second switches of each buck-boost unit in both modules are interleaved and connected in parallel. In this mode, the first switches of each buck-boost unit in both modules are not driven. In other words, when the multiphase buck-boost circuit operates in BUCK mode, only the first switch of each buck-boost unit is active; when the multiphase buck-boost circuit operates in BOOST mode, only the second switch of each buck-boost unit is active.

[0035] Specifically, the first switching transistors of each buck-boost unit of the first multiphase buck-boost module are interleaved and parallel controlled. This means that the phases of the drive signals sent to the first switching transistors of each buck-boost unit of the first multiphase buck-boost module are interleaved, while the amplitudes and periods are the same. This allows the first switching transistors of each buck-boost unit of the first multiphase buck-boost module to be turned on and off alternately.

[0036] By performing interleaved parallel control on the first switching transistors of each buck-boost unit of the second multiphase buck-boost module, the phases of the drive signals sent to the first switching transistors of each buck-boost unit of the second multiphase buck-boost module are interleaved, while the amplitudes and periods are the same. This allows the first switching transistors of each buck-boost unit of the second multiphase buck-boost module to be turned on and off alternately.

[0037] It should be noted that when the multiphase buck-boost circuit is in charging mode, the first switching transistors of the buck-boost units between the first and second multiphase buck-boost modules can be either interleaved or not. For example, the drive signal for the first switching transistor of the Kth buck-boost unit of the first multiphase buck-boost module and the first switching transistor of the Kth buck-boost unit of the second multiphase buck-boost module can be the same; in this case, the first switching transistors of the buck-boost units between the two modules are not interleaved. 1 ≤ K ≤ N, and K is a positive integer.

[0038] By performing interleaved parallel control on the second switching transistors of each buck-boost unit of the first multiphase buck-boost module, the phases of the drive signals sent to the second switching transistors of each buck-boost unit of the first multiphase buck-boost module are interleaved, while the amplitudes and periods are the same. This allows the second switching transistors of each buck-boost unit of the first multiphase buck-boost module to be turned on and off alternately.

[0039] By performing interleaved parallel control on the second switching transistors of each buck-boost unit of the second multiphase buck-boost module, the phases of the drive signals sent to the second switching transistors of each buck-boost unit of the second multiphase buck-boost module are interleaved, while the amplitudes and periods are the same. This allows the second switching transistors of each buck-boost unit of the second multiphase buck-boost module to be turned on and off alternately.

[0040] It should be noted that when the multiphase buck-boost circuit is in discharge mode, the second switching transistors of the buck-boost units between the first and second multiphase buck-boost modules can be either interleaved or not. For example, the drive signal for the second switching transistor of the Kth buck-boost unit of the first and second multiphase buck-boost modules can be the same; in this case, the second switching transistors of the buck-boost units between the two modules are not interleaved.

[0041] In one possible implementation, see Figure 3 Each buck-boost unit in the first and second multiphase buck-boost modules also includes an inductor. The second terminal of the first switch transistor and the first terminal of the second switch transistor in each buck-boost unit are both connected to the second terminal of the inductor of that buck-boost unit, and the first terminal of the inductor of each buck-boost unit is connected to the first terminal.

[0042] Figure 3 A schematic diagram of a multiphase buck-boost circuit with N=2 is shown. (See also...) Figure 3The first multiphase buck-boost module includes two buck-boost units. One buck-boost unit includes an inductor L1, a first switch Q1, and a second switch Q2. The other buck-boost unit includes an inductor L2, a first switch Q3, and a second switch Q4. The second multiphase buck-boost module includes two buck-boost units. One buck-boost unit includes an inductor L3, a first switch Q5, and a second switch Q6. The other buck-boost unit includes an inductor L4, a first switch Q7, and a second switch Q8.

[0043] In one possible implementation, the second port further includes a fifth terminal C, and the third port further includes a sixth terminal D. Both the fifth terminal C and the sixth terminal D are connected to the second terminal BAT-. The first multiphase buck-boost module further includes a first capacitor C1, and the second multiphase buck-boost module further includes a second capacitor C2. The first capacitor C1 has its first end connected to the third terminal A, and its second end connected to both the second terminal BAT- and the fifth terminal C. The second capacitor C2 has its first end connected to the fourth terminal B, and its second end connected to both the second terminal BAT- and the sixth terminal D.

[0044] In some embodiments, see Figure 4 The above-mentioned interleaved parallel control of the first switching transistors of each buck-boost unit in the first multi-phase buck-boost module and the interleaved parallel control of the first switching transistors of each buck-boost unit in the second multi-phase buck-boost module, to make the multi-phase buck-boost circuit work in BUCK mode, includes:

[0045] Obtain the sampling voltage Vbat_fab and sampling current Ibat_fab of the first port;

[0046] The voltage error value of the first port is obtained by subtracting the sampling voltage Vbat_fab of the first port from the control reference voltage Vbat_ref of the first port.

[0047] The charging current is obtained by sampling the current Ibat_fab at the first port, and the current error value of the first port is obtained by subtracting the charging current from the control reference current Ibat_ref at the first port; wherein, the control reference current at the first port is the product of the control given current Ibat_set at the first port and the first preset derating factor.

[0048] Based on the voltage error value and the current error value of the first port, the first switching transistors of each step-up and step-down unit of the first multiphase step-up and step-down module are interleaved and connected in parallel, and the first switching transistors of each step-up and step-down unit of the second multiphase step-up and step-down module are interleaved and connected in parallel, so that the multiphase step-up and step-down circuit works in BUCK mode.

[0049] This embodiment can use existing methods to obtain the sampling voltage Vbat_fab and sampling current Ibat_fab of the first port. The sampling voltage Vbat_fab of the first port is the real-time voltage of the first port, and the sampling current Ibat_fab of the first port is the real-time current of the first port. Since the first port is connected to the first power supply, the sampling voltage Vbat_fab and sampling current Ibat_fab of the first port can also be considered as the sampling voltage and sampling current of the first power supply.

[0050] The control reference voltage Vbat_ref of the first port can be understood as the target voltage of the first port; that is, the sampling voltage Vbat_fab of the first port needs to be adjusted to the target voltage of the first port. The control reference voltage of the first port is a preset voltage value, which can be set according to actual needs.

[0051] The control reference current Ibat_ref of the first port can be understood as the target current of the first port, that is, the sampling current Ibat_fab of the first port needs to be adjusted to the target current of the first port. The control reference current Ibat_ref of the first port is the product of the control given current Ibat_set of the first port and the first preset derating factor.

[0052] The control current Ibat_set for the first port is a pre-set current value that can be set according to actual needs.

[0053] The first preset derating factor is a current-limiting derating factor with a value less than 1, which can be derived from the power derating factor. For example, with a rated power of 30 kilowatts, in high-temperature environments (extreme low-pressure environments, high-pressure environments, certain fault environments), the actual convertible power must be multiplied by this power derating factor for derating operation. The first preset derating factor can be set according to actual needs and is not specifically limited here.

[0054] The charging current is obtained from the sampling current Ibat_fab at the first port. See [reference needed]. Figure 4 The charging current is obtained by multiplying the sampled current Ibat_fab at the first port by -1. In this case, the charging direction is defined as negative and the discharging direction as positive. If the charging direction is defined as positive and the discharging direction as negative, the charging current can be obtained by multiplying the sampled current Ibat_fab at the first port by 1.

[0055] This embodiment can use the voltage error value and the current error value of the first port to perform interleaved parallel control on the first switching transistors of each step-up and step-down unit of the first multiphase step-up and step-down module, and to perform interleaved parallel control on the first switching transistors of each step-up and step-down unit of the second multiphase step-up and step-down module, so that the multiphase step-up and step-down circuit works in BUCK mode.

[0056] In some embodiments, the above-mentioned interleaved parallel control of the first switching transistors of each step-up / step-down unit of the first multiphase step-up / step-down module and the interleaved parallel control of the first switching transistors of each step-up / step-down unit of the second multiphase step-up / step-down module, based on the voltage error value and the current error value of the first port, to make the multiphase step-up / step-down circuit operate in BUCK mode, includes:

[0057] The voltage error value of the first port is input into the first PI controller to obtain the first control quantity;

[0058] The current error value of the first port is input into the second PI controller to obtain the second control quantity;

[0059] The first control quantity and the second control quantity are input into the first limiter to obtain the first limit control quantity;

[0060] The first limiting control quantity is modulated to obtain 2N first drive signals, and the 2N first drive signals are sent to the first switching transistors of the 2N buck-boost units respectively, so that the multiphase buck-boost circuit works in BUCK mode. Each first switching transistor corresponds to one first drive signal. The phase difference between the first drive signal of the first switching transistor of the Mth buck-boost unit of the first multiphase buck-boost module and the first drive signal of the first switching transistor of the (M+1)th buck-boost unit of the first multiphase buck-boost module is 360 / N. The phase difference between the first drive signal of the first switching transistor of the Mth buck-boost unit of the second multiphase buck-boost module and the first drive signal of the first switching transistor of the (M+1)th buck-boost unit of the second multiphase buck-boost module is 360 / N, and 1≤M≤N-1.

[0061] Both the first and second PI controllers are PI controllers with pre-set parameters and can be implemented using existing methods, which will not be elaborated further. The first PI controller outputs a first control value, and the second PI controller outputs a second control value.

[0062] The first limiter is used to limit the various input parameters and output the smaller value among the limited parameters. The limiting operation is an internal data calculation operation. In digital control, data overflow and dynamic operation issues may exist. For example, the normal data range is -100 to 100, but in dynamic or abnormal situations, data may reach 200. Therefore, the data must be limited to not exceed the range of -100 to 100 to protect and improve dynamic performance.

[0063] In this embodiment, after the first control quantity and the second control quantity are respectively subjected to limiting operation, the first limiter obtains the first control quantity and the second control quantity after limiting, and the output first limiting control quantity is the smaller value between the first control quantity and the second control quantity after limiting.

[0064] By modulating the first limiting control quantity, the same number of first drive signals as the number of first switching transistors can be obtained, i.e., 2N first drive signals. Each first drive signal is sent to the corresponding first switching transistor, which can control the multiphase buck-boost circuit to work in BUCK mode.

[0065] In this module, the phase difference between the first drive signal of the first switch transistor of the Mth step-up / step-down unit and the first drive signal of the first switch transistor of the (M+1)th step-up / step-down unit is 360 / N degrees. Specifically, the difference between the first drive signal of the first switch transistor of the Mth step-up / step-down unit and the phase difference between the first drive signal of the (M+1)th step-up / step-down unit is 360 / N degrees. Both signals have the same amplitude and period.

[0066] The phase difference between the first drive signal of the first switch transistor of the Mth step-up / step-down unit of the second multiphase step-up / step-down module and the first drive signal of the first switch transistor of the (M+1)th step-up / step-down unit of the second multiphase step-up / step-down module is 360 / N degrees. That is, the difference between the phase of the first drive signal of the first switch transistor of the Mth step-up / step-down unit of the second multiphase step-up / step-down module and the phase of the first drive signal of the first switch transistor of the (M+1)th step-up / step-down unit of the second multiphase step-up / step-down module is 360 / N degrees. Both signals have the same amplitude and period.

[0067] For example, Figure 4 The Buck control loop in charging mode with N=2 is given. Figure 4In this process, the first limiting control quantity is modulated to obtain four first drive signals, namely PWM1_B, PWM2_B, PWM11_B, and PWM12_B. Each first drive signal is sent to its corresponding first switch transistor, which can control the multiphase buck-boost circuit to operate in BUCK mode. The first drive signal can be a PWM wave.

[0068] This embodiment adopts parallel independent interleaved voltage and current dual closed-loop PI control. The voltage outer loop is adjusted by PI and used as the reference for two independent current inner loops. After the two independent current inner loops are adjusted by PI, they are compared with triangular waves staggered by 180 degrees to generate the corresponding first drive signal.

[0069] In some embodiments, see Figure 3 The third terminal A is used to connect to the positive busbar through the first isolation circuit, and the fourth terminal B is used to connect to the negative busbar through the second isolation circuit; the positive busbar and the negative busbar are also connected to the second power supply through the power conversion circuit;

[0070] See Figure 5 The above-mentioned interleaved parallel control of the second switching transistors of each step-up / step-down unit in the first multi-phase step-up / step-down module and the interleaved parallel control of the second switching transistors of each step-up / step-down unit in the second multi-phase step-up / step-down module, to enable the multi-phase step-up / step-down circuit to operate in BOOST mode, includes:

[0071] Obtain the sampling voltage Vbus_P of the positive bus, and subtract the sampling voltage Vbus_P of the positive bus from the control reference voltage Vbus_P_ref of the positive bus to obtain the voltage error value of the positive bus.

[0072] Obtain the sampling voltage Vbus_N of the negative bus, and subtract the sampling voltage Vbus_N of the negative bus from the control reference voltage Vbus_N_ref of the negative bus to obtain the voltage error value of the negative bus.

[0073] Based on the voltage error values ​​of the positive bus and the negative bus, the second switching transistors of each step-up and step-down unit of the first multiphase step-up and step-down module are interleaved and connected in parallel, and the second switching transistors of each step-up and step-down unit of the second multiphase step-up and step-down module are interleaved and connected in parallel, so that the multiphase step-up and step-down circuit operates in BOOST mode.

[0074] In this embodiment, the second power source is an AC power source. The first isolation circuit is connected to both the positive bus and the neutral (N) line; the second isolation circuit is connected to both the negative bus and the neutral (N) line.

[0075] The first and second isolation circuits can both be bidirectional LLC circuits or bidirectional CLLC circuits, etc. The power conversion circuit is a bidirectional DC-AC circuit, such as a T-type three-level circuit, etc.

[0076] This embodiment controls the second switching transistors of each step-up / step-down unit by controlling the bus voltage, so that the multi-phase step-up / step-down circuit operates in BOOST mode. The ultimate control target is the main bus port, which can reduce the pressure on subsequent regulation.

[0077] The sampling voltage Vbus_P of the positive bus and the sampling voltage Vbus_N of the negative bus can be acquired using existing methods. The sampling voltage Vbus_P of the positive bus is the real-time voltage of the positive bus, and the sampling voltage Vbus_N of the negative bus is the real-time voltage of the negative bus.

[0078] The control reference voltage Vbus_P_ref of the positive bus can be understood as the target voltage of the positive bus, meaning the sampled voltage of the positive bus needs to be adjusted to the target voltage. The control reference voltage Vbus_P_ref of the positive bus is a preset voltage value that can be set according to actual needs. The control reference voltage of the positive bus can be proportionally calculated based on the control reference voltage of the first port, with a lower limit of 360Vdc and an upper limit of 415Vdc.

[0079] The control reference voltage Vbus_N_ref of the negative bus can be understood as the target voltage of the negative bus, meaning the sampled voltage of the negative bus needs to be adjusted to the target voltage. The control reference voltage Vbus_N_ref of the negative bus is a preset voltage value that can be set according to actual needs.

[0080] This embodiment can use the voltage error values ​​of the positive bus and the negative bus to perform interleaved parallel control on the second switching transistors of each step-up and step-down unit of the first multi-phase step-up and step-down module, and to perform interleaved parallel control on the second switching transistors of each step-up and step-down unit of the second multi-phase step-up and step-down module, so that the multi-phase step-up and step-down circuit works in BOOST mode.

[0081] In some embodiments, see Figure 5 The above-mentioned method involves interleaving and paralleling the second switches of each step-up / step-down unit in the first multi-phase step-up / step-down module and the second switches of each step-up / step-down unit in the second multi-phase step-up / step-down module based on the voltage error values ​​of the positive and negative busbars, thereby enabling the multi-phase step-up / step-down circuit to operate in BOOST mode. This includes:

[0082] Obtain the first preset rate limiting data, and multiply the first preset rate limiting data by the first preset coefficient to obtain the target rate limiting data;

[0083] The voltage error value of the positive bus is input into the third PI controller to obtain the third control quantity. The third control quantity and the target current limiting data are input into the second limiter to obtain the second limit control quantity. The second limit control quantity is multiplied by the second preset coefficient to obtain the first target limit control quantity.

[0084] The voltage error value of the negative bus is input into the fourth PI controller to obtain the fourth control quantity. The fourth control quantity and the target current limiting data are input into the third limiter to obtain the third limit control quantity. The third limit control quantity is multiplied by the third preset coefficient to obtain the second target limit control quantity.

[0085] Based on the first target limiting control amount and the second target limiting control amount, the second switching transistors of each buck-boost unit of the first multiphase buck-boost module are interleaved and connected in parallel, and the second switching transistors of each buck-boost unit of the second multiphase buck-boost module are interleaved and connected in parallel, so that the multiphase buck-boost circuit works in BOOST mode.

[0086] The first preset rate limiting data can be rate limiting data sent by the host computer. Specifically, it can be a rate limiting coefficient, similar to the aforementioned first preset rate reduction coefficient, and will not be described in detail here.

[0087] The first preset coefficient can be set according to actual needs. In one possible implementation, the first preset coefficient can be 1 / 2.

[0088] The second and third limiters have the same function as the first limiter mentioned above, and will not be described again.

[0089] The descriptions of the third and fourth PI controllers can be referenced from those of the first and second PI controllers, and will not be repeated here.

[0090] The second preset coefficient can be the second preset reduction coefficient multiplied by 1 / 2, and the third preset coefficient can be the third preset reduction coefficient multiplied by 1 / 2. The descriptions of the second and third preset reduction coefficients can refer to the description of the first preset reduction coefficient mentioned above, and will not be repeated here.

[0091] In this embodiment, the second switching transistors of each buck-boost unit of the first multiphase buck-boost module are interleaved and parallel controlled according to the first target limiting control amount and the second target limiting control amount, and the second switching transistors of each buck-boost unit of the second multiphase buck-boost module are interleaved and parallel controlled, so that the multiphase buck-boost circuit works in BOOST mode.

[0092] In some embodiments, see Figure 5The above-mentioned method, based on the first target limiting control amount and the second target limiting control amount, performs interleaved parallel control on the second switching transistors of each buck-boost unit of the first multiphase buck-boost module, and performs interleaved parallel control on the second switching transistors of each buck-boost unit of the second multiphase buck-boost module, so that the multiphase buck-boost circuit operates in BOOST mode, including:

[0093] Obtain the sampling current of each buck-boost unit in the first and second multiphase buck-boost modules;

[0094] Obtain the total bus sampling voltage U bus and the sampling voltage U of the first port bat And sample the total bus voltage U bus Subtract the sampling voltage U at the first port bat The fixed feedforward parameter values ​​are obtained; the total bus sampling voltage U bus It is the sum of the sampling voltage of the positive bus and the sampling voltage of the negative bus;

[0095] For each buck-boost unit in the first and second multiphase buck-boost modules, the target limiting control value corresponding to the buck-boost unit is subtracted from the sampling current of the buck-boost module to obtain the first current error value of the buck-boost unit. The first current error value of the buck-boost unit is then input into the first current PI controller corresponding to the buck-boost unit to obtain the first PI control value of the buck-boost unit. The first PI control value of the buck-boost unit is then added to the fixed feedforward parameter value to obtain the feedforward control value of the buck-boost unit. The feedforward control value of the buck-boost unit is then multiplied by the bus voltage coefficient to obtain the first target control value of the buck-boost unit. The first target control value of the buck-boost unit is then modulated to obtain the second drive signal corresponding to the buck-boost unit.

[0096] The second drive signal corresponding to each buck-boost unit in the first and second multiphase buck-boost modules is sent to the second switching transistor of the buck-boost unit so that the multiphase buck-boost circuit works in BOOST mode.

[0097] In the first multiphase buck-boost module, the target limiting control quantity corresponding to each buck-boost unit is the first target limiting control quantity; in the second multiphase buck-boost module, the target limiting control quantity corresponding to each buck-boost unit is the second target limiting control quantity; the bus voltage coefficient is the reciprocal of the total bus sampling voltage.

[0098] The phase difference between the second drive signal of the second switch of the Mth step-up / step-down unit of the first multiphase step-up / step-down module and the second drive signal of the second switch of the (M+1)th step-up / step-down unit of the first multiphase step-up / step-down module is 360 / N. The phase difference between the second drive signal of the second switch of the Mth step-up / step-down unit of the second multiphase step-up / step-down module and the second drive signal of the second switch of the (M+1)th step-up / step-down unit of the second multiphase step-up / step-down module is also 360 / N, 1≤M≤N-1.

[0099] Obtaining the sampling current of each buck-boost unit in the first and second multiphase buck-boost modules can be achieved by obtaining the sampling current of the inductor flowing through each buck-boost unit.

[0100] For example, with Figure 3 and Figure 5 For example, Figure 5 This is a schematic diagram of a Boost control loop in discharge mode when N=2. Figure 5 In the process, the sampling current I of one of the buck-boost units in the first multi-phase buck-boost module is obtained. P1 _fdb can be the sampling current of the inductor flowing through the buck-boost unit, or the sampling current I of another buck-boost unit in the first multiphase buck-boost module. P2 _fdb can be the sampling current flowing through the inductor of the buck-boost unit, or the sampling current I of one of the buck-boost units in the second multiphase buck-boost module. N1 _fdb can be the sampled current flowing through the inductor of this buck-boost unit, or the sampled current I of another buck-boost unit in the second multiphase buck-boost module. N2 _fdb can be the sampling current flowing through the inductor of the buck-boost unit.

[0101] See Figure 5 The bus voltage coefficient is 1 / V Bus_Inst V Bus_Inst It is a value related to the total bus sampling voltage, and the two are numerically equal.

[0102] The first current PI controller can be referred to the description of the first PI controller above, and will not be repeated here.

[0103] Figure 5The latter half is divided into four paths, each corresponding to a buck-boost unit. From top to bottom, they correspond to one buck-boost unit in the first multi-phase buck-boost module, another buck-boost unit in the first multi-phase buck-boost module, one buck-boost unit in the second multi-phase buck-boost module, and another buck-boost unit in the second multi-phase buck-boost module. PWM1_UP is the second drive signal for one buck-boost unit in the first multi-phase buck-boost module, sent to the second switch of that unit; PWM2_UP is the second drive signal for the other buck-boost unit in the first multi-phase buck-boost module, sent to the second switch of that unit; PWM1_DOWM is the second drive signal for one buck-boost unit in the second multi-phase buck-boost module, sent to the second switch of that unit; PWM2_DOWM is the second drive signal for the other buck-boost unit in the second multi-phase buck-boost module, sent to the second switch of that unit.

[0104] The amplitudes and periods of all the second drive signals are the same, but the phases of the second drive signals in the same multiphase buck-boost module are staggered.

[0105] It should be noted that Vbat_fab and U... bat Both represent the sampled voltage of the first port, but the sampled voltage of the first port varies depending on the operating mode. Vbat_fab is the sampled voltage of the first port in charging mode, U... bat This is the sampling voltage at the first port in discharge mode.

[0106] In some embodiments, see Figure 3 The third terminal A is used to connect to the positive busbar through the first isolation circuit, and the fourth terminal B is used to connect to the negative busbar through the second isolation circuit; the positive busbar and the negative busbar are also connected to the second power supply through the power conversion circuit;

[0107] See Figure 6 The above-mentioned interleaved parallel control of the second switching transistors of each step-up / step-down unit in the first multi-phase step-up / step-down module and the interleaved parallel control of the second switching transistors of each step-up / step-down unit in the second multi-phase step-up / step-down module, to enable the multi-phase step-up / step-down circuit to operate in BOOST mode, includes:

[0108] Obtain the sampling power Pbat_fdb of the first port, and subtract the sampling power Pbat_fdb of the first port from the control reference power Pbat_ref of the first port to obtain the power error value of the first port;

[0109] Obtain the total bus sampling voltage Vbus_fdb, and subtract the total bus sampling voltage Vbus_fdb from the control reference upper limit Vbus_refH to obtain the total bus voltage error value; the total bus sampling voltage Vbus_fdb is the sum of the sampling voltages of the positive bus and the negative bus.

[0110] Based on the power error value and the total bus voltage error value at the first port, the second switching transistors of each step-up and step-down unit of the first multiphase step-up and step-down module are interleaved and connected in parallel, and the second switching transistors of each step-up and step-down unit of the second multiphase step-up and step-down module are interleaved and connected in parallel, so that the multiphase step-up and step-down circuit operates in BOOST mode.

[0111] It should be noted that Vbus_fdb and U bus All of these are the total bus sampling voltages in discharge mode, but different symbols are used to represent them in different control loops.

[0112] The sampling power Pbat_fdb of the first port can be calculated from the sampling current and sampling voltage of the first port, or it can be obtained through other existing methods.

[0113] The control reference power Pbat_ref of the first port can be obtained by multiplying the control reference current of the first port by the voltage of the first port, or it can be preset using other methods. The control reference power Pbat_ref of the first port can be understood as the target power of the first port, that is, the sampling power of the first port needs to be adjusted to the target power.

[0114] The control reference power of the first port can also be called the control reference power on the DC side, and the control reference power of the port connected to the second power supply can be called the control reference power on the AC side. In charging mode, the control reference power on the AC side multiplied by the charging efficiency equals the control reference power on the DC side; in discharging mode, the control reference power on the DC side multiplied by the discharging efficiency equals the control reference power on the AC side.

[0115] The upper limit of the control reference voltage of the total bus sampling voltage, Vbus_refH, refers to the upper limit of the control reference voltage of the total bus sampling voltage. Since the bus voltage fluctuates sinusoidally, there is an upper limit.

[0116] This embodiment can use the power error value and the total bus voltage error value of the first port to perform interleaved parallel control on the second switching transistors of each step-up and step-down unit of the first multi-phase step-up and step-down module, and to perform interleaved parallel control on the second switching transistors of each step-up and step-down unit of the second multi-phase step-up and step-down module, so that the multi-phase step-up and step-down circuit works in BOOST mode.

[0117] This embodiment controls the second switching transistor of each buck-boost module by controlling the power, so that the multiphase buck-boost circuit works in BOOST mode.

[0118] In some embodiments, see Figure 6 The above-mentioned method involves interleaving and paralleling the second switches of each step-up / step-down unit in the first multi-phase step-up / step-down module and interleaving and paralleling the second switches of each step-up / step-down unit in the second multi-phase step-up / step-down module based on the power error value of the first port and the total bus voltage error value, so that the multi-phase step-up / step-down circuit operates in BOOST mode, including:

[0119] The power error value of the first port is input into the fifth PI controller to obtain the fifth control quantity;

[0120] The total bus voltage error value is input into the sixth PI controller to obtain the sixth control quantity;

[0121] Obtain the second preset rate limiting data;

[0122] The fifth control value, the sixth control value, and the second preset current limiting data are input into the fourth limiter to obtain the fourth limit control value;

[0123] Multiply the fourth amplitude limiting control amount by the fourth preset coefficient to obtain the third target amplitude limiting control amount;

[0124] Based on the third target limiting control amount, the second switching transistors of each step-up and step-down unit of the first multiphase step-up and step-down module are interleaved and connected in parallel, and the second switching transistors of each step-up and step-down unit of the second multiphase step-up and step-down module are interleaved and connected in parallel, so that the multiphase step-up and step-down circuit works in BOOST mode.

[0125] The descriptions of the fifth and sixth PI controllers can be referenced from those of the first and second PI controllers, and will not be repeated here.

[0126] The second preset rate limiting data can refer to the description of the first preset rate limiting data mentioned above; the two can be the same or different.

[0127] The fourth limiter has the same function as the first limiter, so it will not be described again.

[0128] The fourth preset coefficient can be the fourth preset reduction coefficient multiplied by 1 / 4. The description of the fourth preset reduction coefficient can be referred to the description of the first preset reduction coefficient mentioned above, and will not be repeated here.

[0129] In this embodiment, the second switching transistors of each step-up and step-down unit of the first multiphase step-up and step-down module can be interleaved and parallel controlled according to the third target limiting control amount, and the second switching transistors of each step-up and step-down unit of the second multiphase step-up and step-down module can be interleaved and parallel controlled, so that the multiphase step-up and step-down circuit works in BOOST mode.

[0130] In some embodiments, see Figure 6 The above-mentioned, based on the third target limiting control amount, performs interleaved parallel control on the second switching transistors of each buck-boost unit of the first multiphase buck-boost module, and interleaved parallel control on the second switching transistors of each buck-boost unit of the second multiphase buck-boost module, so that the multiphase buck-boost circuit operates in BOOST mode, including:

[0131] Obtain the sampling current of each buck-boost unit in the first and second multiphase buck-boost modules;

[0132] For each buck-boost unit in the first and second multiphase buck-boost modules, the sampling current of the buck-boost unit is subtracted from the third target limiting control value to obtain the second current error value of the buck-boost unit. The second current error value of the buck-boost unit is then input into the second current PI controller corresponding to the buck-boost unit to obtain the second PI control value of the buck-boost unit. The second PI control value of the buck-boost unit is multiplied by the bus voltage coefficient to obtain the second target control value of the buck-boost unit. The second target control value of the buck-boost unit is then modulated to obtain the third drive signal corresponding to the buck-boost unit. The bus voltage coefficient is the reciprocal of the total bus sampling voltage.

[0133] The third drive signal corresponding to each buck-boost unit in the first and second multiphase buck-boost modules is sent to the second switch of the buck-boost unit so that the multiphase buck-boost circuit works in BOOST mode.

[0134] In this module, the phase difference between the third drive signal of the second switch transistor of the Mth step-up / step-down unit and the third drive signal of the second switch transistor of the (M+1)th step-up / step-down unit is 360° / N. Similarly, the phase difference between the third drive signal of the second switch transistor of the Mth step-up / step-down unit and the third drive signal of the second switch transistor of the (M+1)th step-up / step-down unit is 360° / N, where 1 ≤ M ≤ N-1. All third drive signals have the same amplitude and period.

[0135] For example, with Figure 3 and Figure 6 For example, Figure 6 This is a schematic diagram of another Boost control loop in discharge mode when N=2. See [link / reference] Figure 6The latter half is divided into four paths, each corresponding to a buck-boost unit. From top to bottom, these correspond to one buck-boost unit in the first multi-phase buck-boost module, another buck-boost unit in the first multi-phase buck-boost module, one buck-boost unit in the second multi-phase buck-boost module, and another buck-boost unit in the second multi-phase buck-boost module. PWM1_UP1 is the third drive signal for one buck-boost unit in the first multi-phase buck-boost module, sent to the second switch of that unit; PWM2_UP1 is the third drive signal for the other buck-boost unit in the first multi-phase buck-boost module, sent to the second switch of that unit; PWM1_DOWM1 is the third drive signal for one buck-boost unit in the second multi-phase buck-boost module, sent to the second switch of that unit; PWM2_DOWM1 is the third drive signal for the other buck-boost unit in the second multi-phase buck-boost module, sent to the second switch of that unit. This allows the multi-phase buck-boost circuit to operate in BOOST mode.

[0136] The second current PI controller can be referred to the description of the first PI controller mentioned above, and will not be repeated here.

[0137] This embodiment can control the multiphase buck-boost circuit to operate in BOOST mode in two ways, as follows: Figure 5 and Figure 6 As shown.

[0138] The multiphase buck-boost circuit in this embodiment can also be called a multiphase buck / boost circuit. This embodiment, through the above control method, can realize a single-stage multiphase DC-DC interleaved control scheme in bidirectional power conversion, enabling voltage and current equalization across phases, and also achieving bus control, etc.

[0139] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0140] The following are device embodiments of the present invention. For details not described in detail, please refer to the corresponding method embodiments described above.

[0141] Figure 7 A schematic diagram of the control device for a multiphase buck-boost circuit provided in an embodiment of the present invention is shown. For ease of explanation, only the parts related to the embodiment of the present invention are shown, and are described in detail below:

[0142] The multiphase buck-boost circuit includes a first port, a second port, a third port, a first multiphase buck-boost module, and a second multiphase buck-boost module. The first port is used to connect to a first power supply, and both the second port and the third port are used to connect to a second power supply. The first multiphase buck-boost module is connected to the first port and the second port, and the second multiphase buck-boost module is connected to the first port and the third port, respectively. When the multiphase buck-boost circuit is in charging mode, the second power supply charges the first power supply. When the multiphase buck-boost circuit is in discharging mode, the first power supply discharges to the second power supply.

[0143] like Figure 7 As shown, the control device 30 of the multiphase step-up / step-down circuit includes: a first control module 31 and a second control module 32.

[0144] The first control module 31 is used to control the multi-phase buck-boost circuit to work in BUCK mode when the multi-phase buck-boost circuit is in charging mode.

[0145] The second control module 32 is used to control the multiphase buck-boost circuit to work in BOOST mode when the multiphase buck-boost circuit is in discharge mode.

[0146] In one possible implementation, the first port includes a first terminal and a second terminal, the first terminal being used to connect to the positive terminal of the first power supply, and the second terminal being used to connect to the negative terminal of the first power supply; the second port includes a third terminal and a fourth terminal; both the first and second multiphase buck-boost modules include N buck-boost units connected in parallel, where N≥2, and each buck-boost unit includes a first switch and a second switch; the second terminal of the first switch and the first terminal of the second switch in each buck-boost unit are connected to the first terminal, and the second terminal of the second switch in each buck-boost unit is connected to the second terminal; the first terminal of the first switch of each buck-boost unit in the first multiphase buck-boost module is connected to the third terminal; and the first terminal of the first switch of each buck-boost unit in the second multiphase buck-boost module is connected to the fourth terminal.

[0147] The first control module 31 is specifically used for:

[0148] When the multiphase buck-boost circuit is in charging mode, the first switching transistors of each buck-boost unit of the first multiphase buck-boost module are interleaved and connected in parallel, and the first switching transistors of each buck-boost unit of the second multiphase buck-boost module are interleaved and connected in parallel, so that the multiphase buck-boost circuit works in BUCK mode.

[0149] The second control module 32 is specifically used for:

[0150] When the multiphase buck-boost circuit is in discharge mode, the second switching transistors of each buck-boost unit of the first multiphase buck-boost module are interleaved and connected in parallel, and the second switching transistors of each buck-boost unit of the second multiphase buck-boost module are interleaved and connected in parallel, so that the multiphase buck-boost circuit works in BOOST mode.

[0151] In one possible implementation, the first control module 31 is specifically used for:

[0152] Obtain the sampling voltage and sampling current of the first port;

[0153] The voltage error value of the first port is obtained by subtracting the sampling voltage of the first port from the control reference voltage of the first port.

[0154] The charging current is obtained based on the sampling current of the first port, and the current error value of the first port is obtained by subtracting the charging current from the control reference current of the first port; wherein, the control reference current of the first port is the product of the control given current of the first port and the first preset derating factor;

[0155] Based on the voltage error value and the current error value of the first port, the second switching transistors of each step-up and step-down unit of the first multiphase step-up and step-down module are interleaved and connected in parallel, and the second switching transistors of each step-up and step-down unit of the second multiphase step-up and step-down module are interleaved and connected in parallel, so that the multiphase step-up and step-down circuit works in BUCK mode.

[0156] In one possible implementation, the first control module 31 is specifically used for:

[0157] The voltage error value of the first port is input into the first PI controller to obtain the first control quantity;

[0158] The current error value of the first port is input into the second PI controller to obtain the second control quantity;

[0159] The first control quantity and the second control quantity are input into the first limiter to obtain the first limit control quantity;

[0160] The first limiting control quantity is modulated to obtain 2N first drive signals, and the 2N first drive signals are sent to the first switching transistors of the 2N buck-boost units respectively, so that the multiphase buck-boost circuit operates in BUCK mode; wherein, each first switching transistor corresponds to one first drive signal, the phase difference between the first drive signal of the first switching transistor of the Mth buck-boost unit of the first multiphase buck-boost module and the first drive signal of the first switching transistor of the (M+1)th buck-boost unit of the first multiphase buck-boost module is 360 / N, the phase difference between the first drive signal of the first switching transistor of the Mth buck-boost unit of the second multiphase buck-boost module and the first drive signal of the first switching transistor of the (M+1)th buck-boost unit of the second multiphase buck-boost module is 360 / N, 1≤M≤N-1.

[0161] In one possible implementation, the third terminal is used to connect to the positive bus via the first isolation circuit, and the fourth terminal is used to connect to the negative bus via the second isolation circuit; the positive bus and the negative bus are also connected to the second power supply via a power conversion circuit;

[0162] The second control module 32 is specifically used for:

[0163] Obtain the sampling voltage of the positive bus, and subtract the sampling voltage of the positive bus from the control reference voltage of the positive bus to obtain the voltage error value of the positive bus;

[0164] Obtain the sampling voltage of the negative bus, and subtract the sampling voltage of the negative bus from the control reference voltage of the negative bus to obtain the voltage error value of the negative bus;

[0165] Based on the voltage error values ​​of the positive bus and the negative bus, the second switching transistors of each step-up and step-down unit of the first multiphase step-up and step-down module are interleaved and connected in parallel, and the second switching transistors of each step-up and step-down unit of the second multiphase step-up and step-down module are interleaved and connected in parallel, so that the multiphase step-up and step-down circuit operates in BOOST mode.

[0166] In one possible implementation, the second control module 32 is specifically used for:

[0167] Obtain the first preset rate limiting data, and multiply the first preset rate limiting data by the first preset coefficient to obtain the target rate limiting data;

[0168] The voltage error value of the positive bus is input into the third PI controller to obtain the third control quantity. The third control quantity and the target current limiting data are input into the second limiter to obtain the second limit control quantity. The second limit control quantity is multiplied by the second preset coefficient to obtain the first target limit control quantity.

[0169] The voltage error value of the negative bus is input into the fourth PI controller to obtain the fourth control quantity. The fourth control quantity and the target current limiting data are input into the third limiter to obtain the third limit control quantity. The third limit control quantity is multiplied by the third preset coefficient to obtain the second target limit control quantity.

[0170] Based on the first target limiting control amount and the second target limiting control amount, the second switching transistors of each buck-boost unit of the first multiphase buck-boost module are interleaved and connected in parallel, and the second switching transistors of each buck-boost unit of the second multiphase buck-boost module are interleaved and connected in parallel, so that the multiphase buck-boost circuit works in BOOST mode.

[0171] In one possible implementation, the second control module 32 is specifically used for:

[0172] Obtain the sampling current of each buck-boost unit in the first and second multiphase buck-boost modules;

[0173] Obtain the total bus sampling voltage and the sampling voltage of the first port, and subtract the sampling voltage of the first port from the total bus sampling voltage to obtain the fixed feedforward parameter value; the total bus sampling voltage is the sum of the sampling voltage of the positive bus and the sampling voltage of the negative bus;

[0174] For each buck-boost unit in the first and second multiphase buck-boost modules, the target limiting control value corresponding to the buck-boost unit is subtracted from the sampled current of the buck-boost unit to obtain the first current error value of the buck-boost unit. The first current error value of the buck-boost unit is then input into the first current PI controller corresponding to the buck-boost unit to obtain the first PI control value of the buck-boost unit. The first PI control value of the buck-boost unit is then added to the fixed feedforward parameter value to obtain the feedforward control value of the buck-boost unit. The feedforward control value of the buck-boost unit is then multiplied by the bus voltage coefficient to obtain the first target control value of the buck-boost unit. The first target control value of the buck-boost unit is then modulated to obtain the second drive signal corresponding to the buck-boost unit.

[0175] The second drive signal corresponding to each buck-boost unit in the first and second multiphase buck-boost modules is sent to the second switching transistor of the buck-boost unit so that the multiphase buck-boost circuit works in BOOST mode.

[0176] In the first multiphase buck-boost module, the target limiting control quantity corresponding to each buck-boost unit is the first target limiting control quantity; in the second multiphase buck-boost module, the target limiting control quantity corresponding to each buck-boost unit is the second target limiting control quantity; the bus voltage coefficient is the reciprocal of the total bus sampling voltage.

[0177] The phase difference between the second drive signal of the second switch of the Mth step-up / step-down unit of the first multiphase step-up / step-down module and the second drive signal of the second switch of the (M+1)th step-up / step-down unit of the first multiphase step-up / step-down module is 360 / N. The phase difference between the second drive signal of the second switch of the Mth step-up / step-down unit of the second multiphase step-up / step-down module and the second drive signal of the second switch of the (M+1)th step-up / step-down unit of the second multiphase step-up / step-down module is also 360 / N, 1≤M≤N-1.

[0178] In one possible implementation, the third terminal is used to connect to the positive bus via the first isolation circuit, and the fourth terminal is used to connect to the negative bus via the second isolation circuit; the positive bus and the negative bus are also connected to the second power supply via a power conversion circuit;

[0179] The second control module 32 is specifically used for:

[0180] Obtain the sampling power of the first port, and subtract the sampling power of the first port from the control reference power of the first port to obtain the power error value of the first port;

[0181] Obtain the total bus sampling voltage, and subtract the total bus sampling voltage from the control reference upper limit of the total bus sampling voltage to obtain the total bus voltage error value; the total bus sampling voltage is the sum of the sampling voltages of the positive bus and the negative bus.

[0182] The power error value of the first port is input into the fifth PI controller to obtain the fifth control quantity;

[0183] The total bus voltage error value is input into the sixth PI controller to obtain the sixth control quantity;

[0184] Obtain the second preset rate limiting data;

[0185] The fifth control value, the sixth control value, and the second preset current limiting data are input into the fourth limiter to obtain the fourth limit control value;

[0186] Multiply the fourth amplitude limiting control amount by the fourth preset coefficient to obtain the third target amplitude limiting control amount;

[0187] Based on the third target limiting control amount, the second switching transistors of each step-up and step-down unit of the first multiphase step-up and step-down module are interleaved and connected in parallel, and the second switching transistors of each step-up and step-down unit of the second multiphase step-up and step-down module are interleaved and connected in parallel, so that the multiphase step-up and step-down circuit works in BOOST mode.

[0188] In one possible implementation, the second control module 32 is specifically used for:

[0189] Obtain the sampling current of each buck-boost unit in the first and second multiphase buck-boost modules;

[0190] For each buck-boost unit in the first and second multiphase buck-boost modules, the sampling current of the buck-boost unit is subtracted from the third target limiting control value to obtain the second current error value of the buck-boost unit. The second current error value of the buck-boost unit is then input into the second current PI controller corresponding to the buck-boost unit to obtain the second PI control value of the buck-boost unit. The second PI control value of the buck-boost unit is multiplied by the bus voltage coefficient to obtain the second target control value of the buck-boost unit. The second target control value of the buck-boost unit is then modulated to obtain the third drive signal corresponding to the buck-boost unit. The bus voltage coefficient is the reciprocal of the total bus sampling voltage.

[0191] The third drive signal corresponding to each buck-boost unit in the first and second multiphase buck-boost modules is sent to the second switch of the buck-boost unit so that the multiphase buck-boost circuit works in BOOST mode.

[0192] The phase difference between the third drive signal of the second switch of the Mth step-up / step-down unit of the first multiphase step-up / step-down module and the third drive signal of the second switch of the (M+1)th step-up / step-down unit of the first multiphase step-up / step-down module is 360 / N. The phase difference between the third drive signal of the second switch of the Mth step-up / step-down unit of the second multiphase step-up / step-down module and the third drive signal of the second switch of the (M+1)th step-up / step-down unit of the second multiphase step-up / step-down module is 360 / N, and 1≤M≤N-1.

[0193] Figure 8 This is a schematic diagram of the control device provided in an embodiment of the present invention. Figure 8 As shown, the control device 4 in this embodiment includes: a processor 40, a memory 41, and a computer program 42 stored in the memory 41 and executable on the processor 40. When the processor 40 executes the computer program 42, it implements the steps in the control method embodiments of the various multiphase buck-boost circuits described above, for example... Figure 1 S101 to S102 are shown. Alternatively, when the processor 40 executes the computer program 42, it implements the functions of each module / unit in the above-described device embodiments, for example... Figure 7 The functions of modules / units 31 to 32 shown.

[0194] For example, the computer program 42 can be divided into one or more modules / units, which are stored in the memory 41 and executed by the processor 40 to complete the present invention. The 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 the computer program 42 in the control device 4. For example, the computer program 42 can be divided into... Figure 7 Modules / units 31 to 32 are shown.

[0195] The control device 4 can be a controller, or a computing device such as a desktop computer, laptop, handheld computer, or cloud server. The control device 4 may include, but is not limited to, a processor 40 and a memory 41. Those skilled in the art will understand that... Figure 8 This is merely an example of control device 4 and does not constitute a limitation on control device 4. It may include more or fewer components than shown, or combine certain components, or different components. For example, the control device may also include input / output devices, network access devices, buses, etc.

[0196] The processor 40 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0197] The memory 41 can be an internal storage unit of the control device 4, such as a hard disk or memory of the control device 4. The memory 41 can also be an external storage device of the control device 4, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the control device 4. Furthermore, the memory 41 can include both internal storage units and external storage devices of the control device 4. The memory 41 is used to store the computer program and other programs and data required by the control device. The memory 41 can also be used to temporarily store data that has been output or will be output.

[0198] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0199] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0200] In the embodiments provided by this invention, it should be understood that the disclosed apparatus / control devices and methods can be implemented in other ways. For example, the apparatus / control device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0201] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0202] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0203] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the control method embodiments for each of the above-described multi-phase buck-boost circuits. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc. It should be noted that the content contained in the computer-readable medium may be appropriately added to or subtracted from the content as required by the legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium may not include electrical carrier signals and telecommunication signals.

[0204] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A control method for a multiphase step-up / step-down circuit, characterized in that, The multiphase buck-boost circuit includes a first multiphase buck-boost module and a second multiphase buck-boost module, both of which are connected to a first power supply and a second power supply, and each includes N buck-boost units connected in parallel. Each buck-boost unit includes a first switching transistor and a second switching transistor, where N≥2. The control method for the multiphase buck-boost circuit includes: When the multiphase buck-boost circuit is in discharge mode, the second switching transistors of each buck-boost unit of the first multiphase buck-boost module are interleaved and connected in parallel, and the second switching transistors of each buck-boost unit of the second multiphase buck-boost module are interleaved and connected in parallel. However, the first switching transistors of each buck-boost unit of the first and second multiphase buck-boost modules are not driven and controlled, so that the multiphase buck-boost circuit operates in BOOST mode, and the first power supply discharges the second power supply.

2. The control method for the multiphase buck-boost circuit according to claim 1, characterized in that, The multiphase step-up / step-down circuit includes a first port, a second port, and a third port; the first port includes a first terminal and a second terminal, the first terminal being used to connect to the positive terminal of the first power supply, and the second terminal being used to connect to the negative terminal of the first power supply; the second port and the third port are both used to connect to a second power supply and respectively include a third terminal and a fourth terminal; The second end of the first switching transistor and the first end of the second switching transistor of each step-up / step-down unit are both connected to the first terminal, and the second end of the second switching transistor of each step-up / step-down unit is also connected to the second terminal; the first end of the first switching transistor of each step-up / step-down unit included in the first multiphase step-up / step-down module is connected to the third terminal; the first end of the first switching transistor of each step-up / step-down unit included in the second multiphase step-up / step-down module is connected to the fourth terminal. The third terminal is used to connect to the positive bus via the first isolation circuit, and the fourth terminal is used to connect to the negative bus via the second isolation circuit; the positive bus and the negative bus are also connected to the second power supply via a power conversion circuit; The method of interleaving and paralleling the second switches of each step-up and step-down unit of the first multi-phase step-up and step-down module, interleaving and paralleling the second switches of each step-up and step-down unit of the second multi-phase step-up and step-down module, and not driving the first switches of each step-up and step-down unit of the first and second multi-phase step-up and step-down modules, so that the multi-phase step-up and step-down circuit operates in BOOST mode, includes: The sampling voltage of the positive bus is obtained, and the control reference voltage of the positive bus is subtracted from the sampling voltage of the positive bus to obtain the voltage error value of the positive bus. The sampling voltage of the negative bus is obtained, and the control reference voltage of the negative bus is subtracted from the sampling voltage of the negative bus to obtain the voltage error value of the negative bus. Based on the voltage error values ​​of the positive bus and the negative bus, the second switching transistors of each step-up and step-down unit of the first multi-phase step-up and step-down module are subjected to interleaved parallel control, and the second switching transistors of each step-up and step-down unit of the second multi-phase step-up and step-down module are subjected to interleaved parallel control. However, the first switching transistors of each step-up and step-down unit of the first and second multi-phase step-up and step-down modules are not driven, so that the multi-phase step-up and step-down circuit operates in BOOST mode.

3. The control method for the multiphase buck-boost circuit according to claim 2, characterized in that, The step of interleaving and paralleling the second switches of each step-up / step-down unit of the first multi-phase step-up / step-down module and the second switches of each step-up / step-down unit of the second multi-phase step-up / step-down module according to the voltage error values ​​of the positive bus and the negative bus, and not driving the first switches of each step-up / step-down unit of the first and second multi-phase step-up / step-down modules, so that the multi-phase step-up / step-down circuit operates in BOOST mode, includes: Obtain the first preset rate limiting data, and multiply the first preset rate limiting data by the first preset coefficient to obtain the target rate limiting data; The voltage error value of the positive bus is input into the third PI controller to obtain the third control quantity. The third control quantity and the target current limiting data are input into the second limiter to obtain the second limit control quantity. The second limit control quantity is multiplied by the second preset coefficient to obtain the first target limit control quantity. The voltage error value of the negative bus is input into the fourth PI controller to obtain the fourth control quantity. The fourth control quantity and the target current limiting data are input into the third limiter to obtain the third limit control quantity. The third limit control quantity is multiplied by the third preset coefficient to obtain the second target limit control quantity. Based on the first target limiting control amount and the second target limiting control amount, the second switching transistors of each buck-boost unit of the first multiphase buck-boost module are subjected to interleaved parallel control, and the second switching transistors of each buck-boost unit of the second multiphase buck-boost module are subjected to interleaved parallel control. However, the first switching transistors of each buck-boost unit of the first and second multiphase buck-boost modules are not driven, so that the multiphase buck-boost circuit operates in BOOST mode.

4. The control method for the multiphase buck-boost circuit according to claim 3, characterized in that, The step of performing interleaved parallel control on the second switches of each buck-boost unit of the first multiphase buck-boost module and interleaved parallel control on the second switches of each buck-boost unit of the second multiphase buck-boost module, based on the first target limiting control amount and the second target limiting control amount, and not driving the first switches of each buck-boost unit of the first and second multiphase buck-boost modules, so that the multiphase buck-boost circuit operates in BOOST mode, includes: Obtain the sampling current of each buck-boost unit in the first multiphase buck-boost module and the second multiphase buck-boost module; The total bus sampling voltage and the sampling voltage of the first port are obtained, and the sampling voltage of the first port is subtracted from the total bus sampling voltage to obtain a fixed feedforward parameter value; the total bus sampling voltage is the sum of the sampling voltage of the positive bus and the sampling voltage of the negative bus. For each buck-boost unit in the first and second multiphase buck-boost modules, the target limiting control value corresponding to the buck-boost unit is subtracted from the sampling current of the buck-boost unit to obtain the first current error value of the buck-boost unit. The first current error value of the buck-boost unit is then input into the first current PI controller corresponding to the buck-boost unit to obtain the first PI control value of the buck-boost unit. The first PI control value of the buck-boost unit is then added to the fixed feedforward parameter value to obtain the feedforward control value of the buck-boost unit. The feedforward control value of the buck-boost unit is then multiplied by the bus voltage coefficient to obtain the first target control value of the buck-boost unit. The first target control value of the buck-boost unit is then modulated to obtain the second drive signal corresponding to the buck-boost unit. The second drive signal corresponding to each buck-boost unit in the first multiphase buck-boost module and the second multiphase buck-boost module is sent to the second switching transistor of the buck-boost unit so that the multiphase buck-boost circuit works in BOOST mode. Wherein, the target limiting control quantity corresponding to each buck-boost unit in the first multi-phase buck-boost module is the first target limiting control quantity; the target limiting control quantity corresponding to each buck-boost unit in the second multi-phase buck-boost module is the second target limiting control quantity; the bus voltage coefficient is the reciprocal of the total bus sampling voltage; The phase difference between the second drive signal of the second switch of the Mth step-up / step-down unit of the first multiphase step-up / step-down module and the second drive signal of the second switch of the (M+1)th step-up / step-down unit of the first multiphase step-up / step-down module is 360 / N, and the phase difference between the second drive signal of the second switch of the Mth step-up / step-down unit of the second multiphase step-up / step-down module and the second drive signal of the second switch of the (M+1)th step-up / step-down unit of the second multiphase step-up / step-down module is 360 / N, 1≤M≤N-1.

5. The control method for the multiphase buck-boost circuit according to claim 1, characterized in that, The multiphase step-up / step-down circuit includes a first port, a second port, and a third port; the first port includes a first terminal and a second terminal, the first terminal being used to connect to the positive terminal of the first power supply, and the second terminal being used to connect to the negative terminal of the first power supply; the second port and the third port are both used to connect to a second power supply and respectively include a third terminal and a fourth terminal; The second end of the first switching transistor and the first end of the second switching transistor of each step-up / step-down unit are both connected to the first terminal, and the second end of the second switching transistor of each step-up / step-down unit is also connected to the second terminal; the first end of the first switching transistor of each step-up / step-down unit included in the first multiphase step-up / step-down module is connected to the third terminal; the first end of the first switching transistor of each step-up / step-down unit included in the second multiphase step-up / step-down module is connected to the fourth terminal. The third terminal is used to connect to the positive bus via the first isolation circuit, and the fourth terminal is used to connect to the negative bus via the second isolation circuit; the positive bus and the negative bus are also connected to the second power supply via a power conversion circuit; The method of interleaving and paralleling the second switches of each step-up and step-down unit of the first multi-phase step-up and step-down module, interleaving and paralleling the second switches of each step-up and step-down unit of the second multi-phase step-up and step-down module, and not driving the first switches of each step-up and step-down unit of the first and second multi-phase step-up and step-down modules, so that the multi-phase step-up and step-down circuit operates in BOOST mode, includes: Obtain the sampling power of the first port, and subtract the sampling power of the first port from the control reference power of the first port to obtain the power error value of the first port; The total bus sampling voltage is obtained, and the total bus sampling voltage is subtracted from the control reference upper limit of the total bus sampling voltage to obtain the total bus voltage error value; the total bus sampling voltage is the sum of the sampling voltage of the positive bus and the sampling voltage of the negative bus. The power error value of the first port is input into the fifth PI controller to obtain the fifth control quantity; The total bus voltage error value is input into the sixth PI controller to obtain the sixth control quantity; Obtain the second preset rate limiting data; The fifth control quantity, the sixth control quantity, and the second preset current limiting data are input into the fourth limiter to obtain the fourth limiting control quantity; Multiply the fourth amplitude limiting control amount by the fourth preset coefficient to obtain the third target amplitude limiting control amount; According to the third target limiting control amount, the second switching transistors of each buck-boost unit of the first multiphase buck-boost module are interleaved and connected in parallel, and the second switching transistors of each buck-boost unit of the second multiphase buck-boost module are interleaved and connected in parallel. However, the first switching transistors of each buck-boost unit of the first and second multiphase buck-boost modules are not driven and controlled, so that the multiphase buck-boost circuit operates in BOOST mode.

6. The control method for the multiphase buck-boost circuit according to claim 5, characterized in that, The step of performing interleaved parallel control on the second switches of each step-up / step-down unit of the first multi-phase step-up / step-down module and the second switches of each step-up / step-down unit of the second multi-phase step-up / step-down module according to the third target limiting control amount, and not driving the first switches of each step-up / step-down unit of the first and second multi-phase step-up / step-down modules, so that the multi-phase step-up / step-down circuit operates in BOOST mode, includes: Obtain the sampling current of each buck-boost unit in the first multiphase buck-boost module and the second multiphase buck-boost module; For each buck-boost unit in the first and second multiphase buck-boost modules, the sampling current of the buck-boost unit is subtracted from the third target limiting control value to obtain the second current error value of the buck-boost unit. This second current error value is then input to the corresponding second current PI controller to obtain the second PI control value of the buck-boost unit. The second PI control value of the buck-boost unit is multiplied by the bus voltage coefficient to obtain the second target control value of the buck-boost unit. This second target control value is then modulated to obtain the corresponding third drive signal for the buck-boost unit. The bus voltage coefficient is the reciprocal of the total bus sampling voltage. The third drive signal corresponding to each buck-boost unit in the first multiphase buck-boost module and the second multiphase buck-boost module is sent to the second switch of the buck-boost unit so that the multiphase buck-boost circuit works in BOOST mode. Wherein, the phase difference between the third drive signal of the second switch of the Mth step-up / step-down unit of the first multiphase step-up / step-down module and the third drive signal of the second switch of the (M+1)th step-up / step-down unit of the first multiphase step-up / step-down module is 360 / N, and the phase difference between the third drive signal of the second switch of the Mth step-up / step-down unit of the second multiphase step-up / step-down module and the third drive signal of the second switch of the (M+1)th step-up / step-down unit of the second multiphase step-up / step-down module is 360 / N, 1≤M≤N-1.

7. A control method for a multiphase step-up / step-down circuit as described in any one of claims 2-6, characterized in that, The control method for the multiphase buck-boost circuit also includes: When the multiphase buck-boost circuit is in charging mode, the first switching transistors of each buck-boost unit of the first multiphase buck-boost module are interleaved and connected in parallel, and the first switching transistors of each buck-boost unit of the second multiphase buck-boost module are interleaved and connected in parallel. However, the second switching transistors of each buck-boost unit of the first and second multiphase buck-boost modules are not driven and controlled, so that the multiphase buck-boost circuit works in BUCK mode, and the second power supply charges the first power supply.

8. The control method for a multiphase step-up / step-down circuit as described in claim 7, characterized in that, The method of interleaving and paralleling the first switching transistors of each step-up / step-down unit of the first multi-phase step-up / step-down module, interleaving and paralleling the first switching transistors of each step-up / step-down unit of the second multi-phase step-up / step-down module, and not driving the second switching transistors of each step-up / step-down unit of the first and second multi-phase step-up / step-down modules, so that the multi-phase step-up / step-down circuit operates in BUCK mode, includes: Obtain the sampling voltage and sampling current of the first port; The voltage error value of the first port is obtained by subtracting the sampling voltage of the first port from the control reference voltage of the first port. The charging current is obtained based on the sampling current of the first port, and the current error value of the first port is obtained by subtracting the charging current from the control reference current of the first port; wherein, the control reference current of the first port is the product of the control given current of the first port and the first preset derating factor. Based on the voltage error value and the current error value of the first port, the first switching transistors of each step-up and step-down unit of the first multi-phase step-up and step-down module are interleaved and connected in parallel, and the first switching transistors of each step-up and step-down unit of the second multi-phase step-up and step-down module are interleaved and connected in parallel. However, the second switching transistors of each step-up and step-down unit of the first and second multi-phase step-up and step-down modules are not driven and controlled, so that the multi-phase step-up and step-down circuit operates in BUCK mode.

9. The control method for the multiphase buck-boost circuit according to claim 8, characterized in that, The step of performing interleaved parallel control on the first switching transistors of each step-up / step-down unit of the first multi-phase step-up / step-down module and interleaved parallel control on the first switching transistors of each step-up / step-down unit of the second multi-phase step-up / step-down module, based on the voltage error value and current error value of the first port, and without driving control on the second switching transistors of each step-up / step-down unit of the first and second multi-phase step-up / step-down modules, so that the multi-phase step-up / step-down circuit operates in BUCK mode, includes: The voltage error value of the first port is input into the first PI controller to obtain the first control quantity; The current error value of the first port is input into the second PI controller to obtain the second control quantity; The first control quantity and the second control quantity are input into the first limiter to obtain the first limit control quantity; The first limiting control quantity is modulated to obtain 2N first drive signals, and the 2N first drive signals are respectively sent to the first switching transistors of the 2N buck-boost units, so that the multiphase buck-boost circuit operates in BUCK mode; wherein, each first switching transistor corresponds to one first drive signal, the phase difference between the first drive signal of the first switching transistor of the Mth buck-boost unit of the first multiphase buck-boost module and the first drive signal of the first switching transistor of the (M+1)th buck-boost unit of the first multiphase buck-boost module is 360 / N, the phase difference between the first drive signal of the first switching transistor of the Mth buck-boost unit of the second multiphase buck-boost module and the first drive signal of the first switching transistor of the (M+1)th buck-boost unit of the second multiphase buck-boost module is 360 / N, 1≤M≤N-1.

10. A control device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the control method for the multiphase buck-boost circuit as described in any one of claims 1 to 9.

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