Intermediate bus voltage adjustment method, device and two-stage DC converter

Abstract

The present invention discloses an intermediate bus voltage adjustment method, device and two-stage DC converter, which relate to the field of electronic power technology. The intermediate bus voltage adjustment method is used for a two-stage DC converter, which includes a first DC converter and a second DC converter, wherein the first DC converter is connected to an input bus, the second DC converter is connected to an output bus, the first DC converter and the second DC converter are connected through an intermediate bus, one of the first DC converter and the second DC converter is a resonant converter, and the other is a non-resonant converter, and the method includes: adjusting the intermediate bus voltage according to the voltage of the input bus, the voltage of the output bus and the real-time operating frequency of the resonant converter. The present invention can solve the technical problems of low conversion efficiency in some working conditions and system instability of the existing DC converter when facing input voltage fluctuations or changes in load demand.

Description

Technical Field

[0001] The present invention relates to the field of electronic power technology, and in particular to an intermediate bus voltage adjustment method, device and a two-stage DC converter. Background Art

[0002] As a core device in the field of power electronics, the main function of the DC converter is to convert one DC power supply into another DC power supply with different output characteristics. With the development of new energy technologies, such as photovoltaic power generation and wind power generation, DC converters need to adapt to a wider range of input or output voltages to meet the needs of different application scenarios.

[0003] In the prior art, a wider voltage regulation range is achieved by cascading two-stage DC converters. However, the bus voltage of the two-stage DC converter is usually set to a fixed voltage. Thus, when the input voltage or load demand changes, the two-stage DC converter cannot be flexibly adjusted to adapt to these changes, resulting in reduced conversion efficiency under certain operating conditions. Moreover, input voltage fluctuations or load changes may cause the voltage to be too high or too low, thereby affecting the stability and reliability of the two-stage DC converter.

[0004] Therefore, how to adjust the bus voltage of the DC converter has become a problem that needs to be solved urgently. Summary of the invention

[0005] An embodiment of the present invention provides an intermediate bus voltage adjustment method for adjusting the intermediate bus voltage of a two-stage DC converter to solve the technical problems of low conversion efficiency and system instability in some working conditions of the existing DC converter when facing input voltage fluctuations or load demand changes, wherein the two-stage DC converter includes a first DC converter and a second DC converter, the first DC converter is connected to the input bus, the second DC converter is connected to the output bus, the first DC converter and the second DC converter are connected through an intermediate bus, one of the first DC converter and the second DC converter is a resonant converter, and the other is a non-resonant converter; the method includes:

[0006] Determining a first bus target value of the resonant converter and a second bus target value of the non-resonant converter according to the voltage of the input bus, the voltage of the output bus, and the real-time operating frequency of the resonant converter;

[0007] Determining a reference value of the intermediate bus voltage according to the first bus target value and the second bus target value;

[0008] The intermediate bus voltage is adjusted according to the reference value of the intermediate bus voltage.

[0009] In one embodiment, determining a first bus target value of the resonant converter and a second bus target value of the non-resonant converter according to the voltage of the input bus, the voltage of the output bus, and the real-time operating frequency of the resonant converter includes:

[0010] In the case where the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, a first bus target value of the resonant converter is determined according to the voltage of the input bus and the real-time operating frequency of the resonant converter; a second bus target value of the non-resonant converter is determined according to the voltage of the output bus; or

[0011] When the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, the first bus target value of the resonant converter is determined according to the voltage of the output bus and the real-time operating frequency of the resonant converter; and the second bus target value of the non-resonant converter is determined according to the voltage of the input bus.

[0012] In one embodiment, determining a first bus target value of the resonant converter includes:

[0013] Obtaining the real-time operating frequency and resonant frequency of the resonant converter;

[0014] Inputting the real-time operating frequency and the resonant frequency into a closed-loop control system to determine a resonant adjustment voltage;

[0015] When the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, the first bus target value of the resonant converter is determined based on the resonant regulation voltage and the voltage of the input bus; or, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, the first bus target value of the resonant converter is determined based on the resonant regulation voltage and the voltage of the output bus.

[0016] In one embodiment, the first bus target value is calculated according to the following formula:

[0017]

[0018] in, is the first bus target value, To regulate the voltage for resonance, is the number of winding turns of the resonant converter close to the intermediate bus side; when the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, is the number of winding turns of the resonant converter close to the input bus, is the voltage of the input bus, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, is the number of winding turns of the resonant converter close to the output bus, is the voltage of the output bus.

[0019] In one embodiment, determining a second bus target value of the non-resonant converter includes:

[0020] Determining a non-resonant regulation voltage according to a buck-boost operation mode of the non-resonant converter;

[0021] In the case where the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, the second bus target value of the non-resonant converter is determined based on the non-resonant regulation voltage and the voltage of the output bus; or, in the case where the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, the second bus target value of the non-resonant converter is determined based on the non-resonant regulation voltage and the voltage of the input bus.

[0022] In one embodiment, determining the non-resonant regulation voltage according to the buck-boost operation mode of the non-resonant converter includes:

[0023] In the case where the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, if the non-resonant converter is in a boost operation mode, the non-resonant adjustment voltage is a negative value, and if the non-resonant converter is in a buck operation mode, the non-resonant adjustment voltage is a positive value;

[0024] Alternatively, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, if the non-resonant converter is in a boost operation mode, the non-resonant adjustment voltage is a positive value, and if the non-resonant converter is in a buck operation mode, the non-resonant adjustment voltage is a negative value;

[0025] Wherein, the absolute value of the non-resonance regulation voltage is a preset fixed value.

[0026] In one embodiment, the second bus target value is calculated according to the following formula:

[0027]

[0028] in, is the target value of the second busbar, is a non-resonant voltage regulation; when the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, is the voltage of the output bus, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, is the voltage of the input bus.

[0029] In one embodiment, determining the reference value of the intermediate bus voltage according to the first bus target value and the second bus target value includes:

[0030] The maximum value of the first bus target value and the second bus target value is used as a reference value of the intermediate bus voltage.

[0031] The embodiment of the present invention further provides an intermediate bus voltage adjustment device, which is used to adjust the intermediate bus voltage of a two-stage DC converter to solve the technical problems of low conversion efficiency and system instability in some working conditions of the existing DC converter when facing input voltage fluctuations or load demand changes, wherein the two-stage DC converter includes a first DC converter and a second DC converter, the first DC converter is connected to the input bus, the second DC converter is connected to the output bus, the first DC converter and the second DC converter are connected through an intermediate bus, one of the first DC converter and the second DC converter is a resonant converter, and the other is a non-resonant converter; the device includes:

[0032] A first processing module, configured to determine a first bus target value of the resonant converter and a second bus target value of the non-resonant converter according to a voltage of the input bus, a voltage of the output bus, and a real-time operating frequency of the resonant converter;

[0033] a second processing module, configured to determine a reference value of the intermediate bus voltage according to the first bus target value and the second bus target value;

[0034] An adjustment module is used to adjust the intermediate bus voltage according to a reference value of the intermediate bus voltage.

[0035] The embodiment of the present invention further provides a two-stage DC converter, comprising a first DC converter, a second DC converter and the above-mentioned intermediate bus voltage adjustment device;

[0036] Among them, the first DC converter is connected to the input bus, the second DC converter is connected to the output bus, the first DC converter and the second DC converter are connected through an intermediate bus, one of the first DC converter and the second DC converter is a resonant converter, and the other is a non-resonant converter; the intermediate bus voltage adjustment device is connected to the first DC converter and the second DC converter.

[0037] An embodiment of the present invention further provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned intermediate bus voltage adjustment method when executing the computer program.

[0038] An embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned intermediate bus voltage adjustment method is implemented.

[0039] An embodiment of the present invention further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the above-mentioned intermediate bus voltage adjustment method is implemented.

[0040] The intermediate bus voltage adjustment method provided by the embodiment of the present invention is used for a two-stage DC converter, the two-stage DC converter includes a first DC converter and a second DC converter, the first DC converter is connected to the input bus, the second DC converter is connected to the output bus, the first DC converter and the second DC converter are connected through the intermediate bus, one of the first DC converter and the second DC converter is a resonant converter, and the other is a non-resonant converter; the method includes: determining the first bus target value of the resonant converter and the second bus target value of the non-resonant converter according to the voltage of the input bus, the voltage of the output bus and the real-time operating frequency of the resonant converter; determining the reference value of the intermediate bus voltage according to the first bus target value and the second bus target value; and adjusting the intermediate bus voltage according to the reference value of the intermediate bus voltage. In this way, the efficiency and stability of the two-stage DC converter can be improved by dynamically adjusting the intermediate bus voltage according to the voltage of the input bus, the voltage of the output bus and the real-time operating frequency of the resonant converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] In the attached picture:

[0043] Figure 1 is a structural diagram of a two-stage DC converter in an embodiment of the present invention;

[0044] Figure 2 This is a flow chart of a method for adjusting the intermediate bus voltage in an embodiment of the present invention;

[0045] Figure 3is an architecture diagram of a closed-loop control system in an embodiment of the present invention;

[0046] Figure 4 This is a structural example diagram of a two-stage DC converter in an embodiment of the present invention;

[0047] Figure 5 This is a structural example diagram of another two-stage DC converter in an embodiment of the present invention;

[0048] Figure 6 is a schematic diagram of an intermediate bus voltage adjustment device in an embodiment of the present invention;

[0049] Figure 7 Schematic diagram of a computer device in an embodiment of the present invention. DETAILED DESCRIPTION

[0050] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0051] In the description of this specification, the terms "include", "including", "have", "contain", etc. are all open terms, which mean including but not limited to. The descriptions with reference to the terms "one embodiment", "a specific embodiment", "some embodiments", "for example", etc. mean that the specific features, structures or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. The order of steps involved in each embodiment is used to schematically illustrate the implementation of the present application, and the order of steps is not limited and can be appropriately adjusted as needed.

[0052] It has been found through research that in the prior art, the bus voltage of the DC converter is usually set to a fixed voltage, which has the following problems:

[0053] 1. Low conversion efficiency: When the load is light, if the fixed voltage is set too high, the DC converter needs to consume extra energy to maintain the high bus voltage, which will lead to energy waste. In addition, if the input voltage or load demand changes, the DC converter may not be able to flexibly adjust to adapt to these changes, resulting in reduced conversion efficiency in some working conditions.

[0054] 2. Reduced system stability and reliability: When faced with input voltage fluctuations or load changes, the set fixed voltage may cause the voltage to be too high or too low, which will affect the stability and reliability of the two-stage DC converter.

[0055] Based on this, an embodiment of the present invention provides an intermediate bus voltage adjustment scheme, which is for adjusting the intermediate bus voltage of a two-stage DC converter, wherein the structure of the two-stage DC converter is as follows Figure 1 As shown, the two-stage DC converter may include a first DC converter and a second DC converter, the first DC converter is connected to the input bus, the second DC converter is connected to the output bus, the first DC converter and the second DC converter are connected via an intermediate bus, one of the first DC converter and the second DC converter is a resonant converter, and the other is a non-resonant converter, so that the intermediate bus voltage of the two-stage DC converter can be dynamically adjusted according to the voltage of the input bus, the voltage of the output bus and the real-time operating frequency of the resonant converter to solve the problem caused by the above-mentioned bus voltage being set to a fixed voltage.

[0056] like Figure 2 FIG. 1 is a flow chart of a method for adjusting the intermediate bus voltage provided by an embodiment of the present invention. The method can be used to adjust the intermediate bus voltage. Figure 1 The intermediate bus voltage of the two-stage DC converter shown is adjusted, and the method may include:

[0057] Step 201, determining a first bus target value of the resonant converter and a second bus target value of the non-resonant converter according to the voltage of the input bus, the voltage of the output bus and the real-time operating frequency of the resonant converter;

[0058] Step 202, determining a reference value of the intermediate bus voltage according to the first bus target value and the second bus target value;

[0059] Step 203: adjusting the intermediate bus voltage according to the reference value of the intermediate bus voltage.

[0060] It should be noted that the executor of the intermediate bus voltage adjustment method provided in the embodiment of the present invention can be a two-stage DC converter, or an electronic device connected to the two-stage DC converter for communication, or a functional module or functional entity in the electronic device that can implement the intermediate bus voltage adjustment method. The above-mentioned electronic devices include but are not limited to mobile phones, tablet computers, computers, cameras and wearable devices.

[0061] The above-mentioned intermediate bus voltage adjustment method is described below.

[0062] In specific implementation, in step 201, first, the first bus target value of the resonant converter and the second bus target value of the non-resonant converter can be determined according to the voltage of the input bus, the voltage of the output bus and the real-time operating frequency of the resonant converter, wherein the first bus target value of the resonant converter can be understood as the expected voltage value of the resonant converter to the intermediate bus; the second bus target value of the non-resonant converter can be understood as the expected voltage value of the non-resonant converter to the intermediate bus. Based on this, in steps 202 and 203, the reference value of the intermediate bus voltage can be determined according to the expected voltage value of the resonant converter to the intermediate bus and the expected voltage value of the non-resonant converter to the intermediate bus, and then the intermediate bus voltage can be adjusted according to the reference value of the intermediate bus voltage.

[0063] The embodiments of the present invention can be divided into two cases: the first case is that the first DC converter is a resonant converter and the second DC converter is a non-resonant converter; the second case is that the first DC converter is a non-resonant converter and the second DC converter is a resonant converter.

[0064] For the above two situations, determining the first bus target value of the resonant converter and the second bus target value of the non-resonant converter, that is, the above step 201, may specifically include:

[0065] In the case where the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, a first bus target value of the resonant converter is determined according to the voltage of the input bus and the real-time operating frequency of the resonant converter; a second bus target value of the non-resonant converter is determined according to the voltage of the output bus; or

[0066] When the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, the first bus target value of the resonant converter is determined according to the voltage of the output bus and the real-time operating frequency of the resonant converter; and the second bus target value of the non-resonant converter is determined according to the voltage of the input bus.

[0067] In specific implementation, when the first DC converter is a resonant converter, the resonant converter is connected to the input bus, and the non-resonant converter is connected to the output bus. The first bus target value can be determined according to the voltage of the input bus and the real-time operating frequency of the resonant converter, and the second bus target value can be determined according to the voltage of the output bus; when the second DC converter is a resonant converter, the resonant converter is connected to the output bus, and the non-resonant converter is connected to the input bus. The first bus target value can be determined according to the voltage of the output bus and the real-time operating frequency of the resonant converter, and the second bus target value can be determined according to the voltage of the input bus.

[0068] In one embodiment, the above-mentioned determination of the first bus target value of the resonant converter may specifically include:

[0069] Obtaining the real-time operating frequency and resonant frequency of the resonant converter;

[0070] Inputting the real-time operating frequency and the resonant frequency into a closed-loop control system to determine a resonant adjustment voltage;

[0071] When the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, the first bus target value of the resonant converter is determined based on the resonant regulation voltage and the voltage of the input bus; or, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, the first bus target value of the resonant converter is determined based on the resonant regulation voltage and the voltage of the output bus.

[0072] In a specific implementation, the above-mentioned resonant regulation voltage is a regulation voltage that makes the resonant converter work as close to the resonance point as possible, which can be calculated by a closed-loop control system. The closed-loop control system architecture is as follows: Figure 3 Specifically, Figure 3 As shown, the closed-loop control system includes a comparator and a regulator. The comparator is used to convert the input parameter FfD and FreRef Compare them and get the error between them, where FfD is the real-time operating frequency of the resonant converter, which can be obtained through the output parameters of the resonant converter; FreRef It refers to the frequency when the inductive reactance (XL) and capacitive reactance (XC) of the circuit are equal in the resonant circuit, that is, the resonant frequency, which can be calculated in advance according to the resonant frequency calculation formula. No unnecessary details are given here. The regulator is used to process the error between the two and output the resonant adjustment voltage. , where the regulator can be a PI regulator, a PD regulator, an adaptive regulator, etc., and can be set according to actual needs.

[0073] In one embodiment, the resonant regulation voltage is obtained. After that, the first bus target value can be calculated according to the following formula:

[0074]

[0075] in, is the first bus target value, To regulate the voltage for resonance, is the number of winding turns of the resonant converter close to the intermediate bus side; when the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, is the number of winding turns of the resonant converter close to the input bus, is the voltage of the input bus, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, is the number of winding turns of the resonant converter close to the output bus, is the voltage of the output bus.

[0076] In specific implementation, in the above formula, the number of winding turns of the resonant converter close to the intermediate bus side and the number of winding turns of the resonant converter close to the input bus side (or the number of winding turns of the resonant converter close to the output bus side) are pre-obtained parameters of the resonant converter.

[0077] In one embodiment, the above-mentioned determination of the second bus target value of the non-resonant converter may specifically include:

[0078] Determining a non-resonant regulation voltage according to a buck-boost operation mode of the non-resonant converter;

[0079] When the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, the second bus target value of the non-resonant converter is determined based on the non-resonant regulation voltage and the voltage of the output bus; or, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, the second bus target value of the non-resonant converter is determined based on the non-resonant regulation voltage and the voltage of the input bus.

[0080] In one embodiment, determining the non-resonant regulation voltage according to the buck-boost operation mode of the non-resonant converter may specifically include:

[0081] In the case where the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, if the non-resonant converter is in a boost operation mode, the non-resonant adjustment voltage is a negative value, and if the non-resonant converter is in a buck operation mode, the non-resonant adjustment voltage is a positive value;

[0082] Alternatively, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, if the non-resonant converter is in a boost operation mode, the non-resonant adjustment voltage is a positive value, and if the non-resonant converter is in a buck operation mode, the non-resonant adjustment voltage is a negative value;

[0083] The absolute value of the non-resonance regulation voltage is a preset fixed value.

[0084] In specific implementation, there will be a dead zone when the non-resonant converter is designed for wave generation. The size of the dead zone time will affect the output performance and efficiency of the non-resonant converter. Therefore, a fixed value, i.e., the absolute value of the non-resonant regulation voltage, can be calculated based on the maximum specification voltage and dead zone time of the non-resonant converter.

[0085] In the embodiment of the present invention, the positive and negative values ​​of the non-resonant regulation voltage are related to the buck-boost operation mode and the connection position of the non-resonant converter. When the second DC converter is a non-resonant converter, the non-resonant converter is connected to the output bus. If the non-resonant converter is in the boost operation mode, the intermediate bus voltage is lower than the output bus voltage, so the non-resonant regulation voltage is a negative value. If the non-resonant converter is in the buck operation mode, the intermediate bus voltage is higher than the output bus voltage, so the non-resonant regulation voltage is a positive value. When the first DC converter is a non-resonant converter, the non-resonant converter is connected to the input bus. If the non-resonant converter is in the boost operation mode, the intermediate bus voltage is higher than the input bus voltage, so the non-resonant regulation voltage is a positive value. If the non-resonant converter is in the buck operation mode, the intermediate bus voltage is lower than the input bus voltage, so the non-resonant regulation voltage is a negative value.

[0086] It should be noted that the operating mode of the non-resonant converter can be determined according to the buck-boost type of the non-resonant converter. If the non-resonant converter is a boost converter, then only the boost operating mode is supported; if it is a buck converter, then only the buck operating mode is supported; if it is a boost-and-buck converter, then it is in the boost operating mode when boosting and in the buck operating mode when bucking.

[0087] In one embodiment, after the non-resonant regulation voltage is obtained, the second bus target value may be calculated according to the following formula:

[0088]

[0089] in, is the target value of the second busbar, is a non-resonant voltage regulation; when the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, is the voltage of the output bus, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, is the voltage of the input bus.

[0090] In this way, based on the above embodiment, the first bus target value of the resonant converter and the second bus target value of the non-resonant converter can be obtained. Since the actual voltage value of the intermediate bus needs to at least reach the expected voltage value (i.e., the first bus target value and the second bus target value) to meet the working requirements of the DC converter, in one embodiment, step 202 may specifically include:

[0091] The maximum value of the first bus target value and the second bus target value is used as a reference value of the intermediate bus voltage.

[0092] In specific implementation, the reference value of the intermediate bus voltage can be calculated by the following formula:

[0093]

[0094] in, is the reference value of the intermediate bus voltage.

[0095] In specific implementation, the reference value of the intermediate bus voltage can be sent to the power control module of the two-stage DC converter, and the power control module generates a PWM wave to control the voltage value of the intermediate bus to the reference value of the intermediate bus voltage.

[0096] In summary, in the embodiment of the present invention, the intermediate bus voltage adjustment method of the above-mentioned two-stage DC converter dynamically adjusts the intermediate bus voltage according to the voltage of the input bus, the voltage of the output bus and the real-time operating frequency of the resonant converter, which can improve the efficiency and stability of the two-stage DC converter.

[0097] In order to more clearly understand the above intermediate bus voltage adjustment method, two specific examples are used for explanation below.

[0098] Example 1:

[0099] Figure 4 This is a structural example diagram of a two-stage DC converter provided by an embodiment of the present invention. Figure 4 The first DC converter is a CLLC resonant converter, and the second DC converter is a BUCK converter (non-resonant converter). The ratio of the number of turns of the winding close to the intermediate bus side and the number of turns of the winding close to the input bus side of the CLLC resonant converter is 1:1.

[0100] The first bus target value can be calculated based on the voltage of the input bus and the real-time operating frequency of the CLLC resonant converter. Specifically, it can be calculated using the following formula:

[0101]

[0102] in, is the voltage of the input bus, The resonant regulation voltage is calculated by the real-time operating frequency and resonant frequency input closed-loop control system of the CLLC resonant converter.

[0103] The second bus target value can be determined according to the voltage of the output bus. Specifically, it can be calculated by the following formula:

[0104]

[0105] in, is the output bus voltage, The non-resonant voltage regulation is used. Since the BUCK converter is a step-down converter, its working mode is the step-down working mode, and the BUCK converter is connected to the output bus. Therefore, the intermediate bus voltage is higher than the output bus voltage. The non-resonant voltage regulation >0.

[0106] Will and The larger value of is used as the reference value of the intermediate bus voltage, and the reference value of the intermediate bus voltage is sent to the power control module of the two-stage DC converter. The power control module generates a PWM wave to control the intermediate bus voltage value to the reference value of the intermediate bus voltage.

[0107] Example 2:

[0108] Figure 5 This is another structural example diagram of a two-stage DC converter provided by an embodiment of the present invention. Figure 5 The first DC converter is a BUCK converter (non-resonant converter), and the second DC converter is a CLLC resonant converter. The ratio of the number of turns of the winding close to the intermediate bus side and the number of turns of the winding close to the output bus side of the CLLC resonant converter is 1:1.

[0109] The first bus target value can be calculated based on the voltage of the output bus and the real-time operating frequency of the CLLC resonant converter. Specifically, it can be calculated using the following formula:

[0110]

[0111] in, is the output bus voltage, The resonant regulation voltage is calculated by the real-time operating frequency and resonant frequency input closed-loop control system of the CLLC resonant converter.

[0112] The second bus target value can be determined according to the voltage of the input bus. Specifically, it can be calculated by the following formula:

[0113]

[0114] in, is the voltage of the input bus, The non-resonant voltage regulation is used. Since the BUCK converter is a step-down converter, its working mode is the step-down working mode, and the BUCK converter is connected to the input bus. Therefore, the intermediate bus voltage is lower than the input bus voltage. The non-resonant voltage regulation <0.

[0115] Will and The larger value of is used as the reference value of the intermediate bus voltage, and the reference value of the intermediate bus voltage is sent to the power control module of the two-stage DC converter. The power control module generates a PWM wave to control the intermediate bus voltage value to the reference value of the intermediate bus voltage.

[0116] The present invention also provides an intermediate bus voltage adjustment device, as described in the following embodiments. Since the principle of solving the problem by the device is similar to the above intermediate bus voltage adjustment method, the implementation of this method can refer to the implementation of the intermediate bus voltage adjustment method, and the repeated parts will not be repeated.

[0117] like Figure 6 As shown, it is a schematic diagram of an intermediate bus voltage adjustment device provided by an embodiment of the present invention, the device is used for a two-stage DC converter, the two-stage DC converter includes a first DC converter and a second DC converter, the first DC converter is connected to an input bus, the second DC converter is connected to an output bus, the first DC converter and the second DC converter are connected through an intermediate bus, one of the first DC converter and the second DC converter is a resonant converter, and the other is a non-resonant converter; the device may include the following modules:

[0118] A first processing module 601 is used to determine a first bus target value of the resonant converter and a second bus target value of the non-resonant converter according to the voltage of the input bus, the voltage of the output bus and the real-time operating frequency of the resonant converter;

[0119] A second processing module 602 is used to determine a reference value of the intermediate bus voltage according to the first bus target value and the second bus target value;

[0120] The adjustment module 603 is used to adjust the intermediate bus voltage according to the reference value of the intermediate bus voltage.

[0121] In one embodiment, the first processing module 601 may be specifically used for:

[0122] In the case where the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, a first bus target value of the resonant converter is determined according to the voltage of the input bus and the real-time operating frequency of the resonant converter; a second bus target value of the non-resonant converter is determined according to the voltage of the output bus; or

[0123] When the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, the first bus target value of the resonant converter is determined according to the voltage of the output bus and the real-time operating frequency of the resonant converter; and the second bus target value of the non-resonant converter is determined according to the voltage of the input bus.

[0124] In one embodiment, the first processing module 601 may also be used to:

[0125] Obtaining the real-time operating frequency and resonant frequency of the resonant converter;

[0126] Inputting the real-time operating frequency and the resonant frequency into a closed-loop control system to determine a resonant adjustment voltage;

[0127] When the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, the first bus target value of the resonant converter is determined based on the resonant regulation voltage and the voltage of the input bus; or, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, the first bus target value of the resonant converter is determined based on the resonant regulation voltage and the voltage of the output bus.

[0128] In one embodiment, the first processing module 601 is used to calculate the first bus target value according to the following formula:

[0129]

[0130] in, is the first bus target value, To regulate the voltage for resonance, is the number of winding turns of the resonant converter close to the intermediate bus side; when the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, is the number of winding turns of the resonant converter close to the input bus, is the voltage of the input bus, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, is the number of winding turns of the resonant converter close to the output bus, is the voltage of the output bus.

[0131] In one embodiment, the first processing module 601 may also be used to:

[0132] Determining a non-resonant regulation voltage according to a buck-boost operation mode of the non-resonant converter;

[0133] In the case where the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, the second bus target value of the non-resonant converter is determined based on the non-resonant regulation voltage and the voltage of the output bus; or, in the case where the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, the second bus target value of the non-resonant converter is determined based on the non-resonant regulation voltage and the voltage of the input bus.

[0134] In one embodiment, the first processing module 601 may also be used to:

[0135] In the case where the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, if the non-resonant converter is in a boost operation mode, the non-resonant adjustment voltage is a negative value, and if the non-resonant converter is in a buck operation mode, the non-resonant adjustment voltage is a positive value;

[0136] Alternatively, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, if the non-resonant converter is in a boost operation mode, the non-resonant adjustment voltage is a positive value, and if the non-resonant converter is in a buck operation mode, the non-resonant adjustment voltage is a negative value;

[0137] Wherein, the absolute value of the non-resonance regulation voltage is a preset fixed value.

[0138] In one embodiment, the first processing module 601 may also be used to calculate the second bus target value according to the following formula:

[0139]

[0140] in, is the target value of the second busbar, is a non-resonant voltage regulation; when the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, is the voltage of the output bus, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, is the voltage of the input bus.

[0141] In one embodiment, the second processing module 602 may be specifically configured to:

[0142] The maximum value of the first bus target value and the second bus target value is used as a reference value of the intermediate bus voltage.

[0143] The embodiment of the present invention further provides a two-stage DC converter, which includes a first DC converter, a second DC converter and the above-mentioned intermediate bus voltage adjustment device;

[0144] Among them, the first DC converter is connected to the input bus, the second DC converter is connected to the output bus, the first DC converter and the second DC converter are connected through an intermediate bus, one of the first DC converter and the second DC converter is a resonant converter, and the other is a non-resonant converter; the intermediate bus voltage adjustment device is connected to the first DC converter and the second DC converter.

[0145] It should be noted that the two-stage DC converter of the embodiment of the present invention is applicable to a variety of application scenarios. Its input bus is compatible with a variety of DC power sources such as power grid + inverter, energy storage battery, photovoltaic panel, etc., and the output bus is designed to connect DC loads such as energy storage battery and DC charging pile. The two-stage converter improves system compatibility and reliability through flexible power supply adaptation and load support, and meets a wide range of DC power conversion needs.

[0146] An embodiment of the present invention further provides a computer device, Figure 7 It is a schematic diagram of a computer device in an embodiment of the present invention. The computer device 700 includes a memory 710, a processor 720, and a computer program 730 stored in the memory 710 and executable on the processor 720. When the processor 720 executes the computer program 730, the above-mentioned intermediate bus voltage adjustment method is implemented.

[0147] An embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned intermediate bus voltage adjustment method is implemented.

[0148] An embodiment of the present invention further provides a computer program product, which includes a computer program. When the computer conversion program is executed by a processor, the above-mentioned intermediate bus voltage adjustment method is implemented.

[0149] The intermediate bus voltage adjustment method provided by the embodiment of the present invention is used for a two-stage DC converter, the two-stage DC converter includes a first DC converter and a second DC converter, the first DC converter is connected to the input bus, the second DC converter is connected to the output bus, the first DC converter and the second DC converter are connected through the intermediate bus, one of the first DC converter and the second DC converter is a resonant converter, and the other is a non-resonant converter; the method includes: determining the first bus target value of the resonant converter and the second bus target value of the non-resonant converter according to the voltage of the input bus, the voltage of the output bus and the real-time operating frequency of the resonant converter; determining the reference value of the intermediate bus voltage according to the first bus target value and the second bus target value; and adjusting the intermediate bus voltage according to the reference value of the intermediate bus voltage. In this way, the efficiency and stability of the two-stage DC converter can be improved by dynamically adjusting the intermediate bus voltage according to the voltage of the input bus, the voltage of the output bus and the real-time operating frequency of the resonant converter.

[0150] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0151] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0152] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0153] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0154] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for adjusting an intermediate bus voltage, characterized in that: For a two-stage DC converter, the two-stage DC converter comprises a first DC converter and a second DC converter, the first DC converter is connected to an input bus, the second DC converter is connected to an output bus, the first DC converter and the second DC converter are connected via an intermediate bus, one of the first DC converter and the second DC converter is a resonant converter, and the other is a non-resonant converter; the intermediate bus voltage adjustment method comprises: Determining a first bus target value of the resonant converter and a second bus target value of the non-resonant converter according to the voltage of the input bus, the voltage of the output bus, and the real-time operating frequency of the resonant converter; Determining a reference value of the intermediate bus voltage according to the first bus target value and the second bus target value; adjusting the intermediate bus voltage according to the reference value of the intermediate bus voltage; Determining a first bus target value of the resonant converter and a second bus target value of the non-resonant converter according to the voltage of the input bus, the voltage of the output bus, and the real-time operating frequency of the resonant converter includes: In the case where the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, a first bus target value of the resonant converter is determined according to the voltage of the input bus and the real-time operating frequency of the resonant converter; a second bus target value of the non-resonant converter is determined according to the voltage of the output bus; or In the case where the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, a first bus target value of the resonant converter is determined according to the voltage of the output bus and the real-time operating frequency of the resonant converter; and a second bus target value of the non-resonant converter is determined according to the voltage of the input bus; Determining a first bus target value of the resonant converter includes: Obtaining the real-time operating frequency and resonant frequency of the resonant converter; Inputting the real-time operating frequency and the resonant frequency into a closed-loop control system to determine a resonant adjustment voltage; When the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, the first bus target value of the resonant converter is determined based on the resonant regulation voltage and the voltage of the input bus; or, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, the first bus target value of the resonant converter is determined based on the resonant regulation voltage and the voltage of the output bus.

2. The method according to claim 1, characterized in that The first bus target value is calculated according to the following formula: in, is the first busbar target value, To regulate the voltage for resonance, is the number of winding turns of the resonant converter close to the intermediate bus side; when the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, is the number of winding turns of the resonant converter close to the input bus, is the voltage of the input bus, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, is the number of winding turns of the resonant converter close to the output bus, is the voltage of the output bus.

3. The method according to claim 1, characterized in that Determining a second bus target value of the non-resonant converter includes: Determining a non-resonant regulation voltage according to a buck-boost operation mode of the non-resonant converter; In the case where the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, the second bus target value of the non-resonant converter is determined based on the non-resonant regulation voltage and the voltage of the output bus; or, in the case where the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, the second bus target value of the non-resonant converter is determined based on the non-resonant regulation voltage and the voltage of the input bus.

4. The method according to claim 3, characterized in that Determining the non-resonant regulation voltage according to the buck-boost operation mode of the non-resonant converter includes: In the case where the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, if the non-resonant converter is in a boost operation mode, the non-resonant adjustment voltage is a negative value, and if the non-resonant converter is in a buck operation mode, the non-resonant adjustment voltage is a positive value; Alternatively, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, if the non-resonant converter is in a boost operation mode, the non-resonant adjustment voltage is a positive value, and if the non-resonant converter is in a buck operation mode, the non-resonant adjustment voltage is a negative value; Wherein, the absolute value of the non-resonance regulation voltage is a preset fixed value.

5. The method according to any one of claims 3 to 4, characterized in that: The second bus target value is calculated according to the following formula: in, is the target value of the second busbar, is a non-resonant voltage regulation; when the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, is the voltage of the output bus, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, is the voltage of the input bus.

6. The method according to claim 1, characterized in that Determining a reference value of the intermediate bus voltage according to the first bus target value and the second bus target value includes: The maximum value of the first bus target value and the second bus target value is used as a reference value of the intermediate bus voltage.

7. An intermediate bus voltage adjustment device, characterized in that: For a two-stage DC converter, the two-stage DC converter comprises a first DC converter and a second DC converter, the first DC converter is connected to an input bus, the second DC converter is connected to an output bus, the first DC converter and the second DC converter are connected via an intermediate bus, one of the first DC converter and the second DC converter is a resonant converter, and the other is a non-resonant converter; the intermediate bus voltage adjustment device comprises: A first processing module, configured to determine a first bus target value of the resonant converter and a second bus target value of the non-resonant converter according to a voltage of the input bus, a voltage of the output bus, and a real-time operating frequency of the resonant converter; a second processing module, configured to determine a reference value of the intermediate bus voltage according to the first bus target value and the second bus target value; An adjustment module, used for adjusting the intermediate bus voltage according to a reference value of the intermediate bus voltage; The first processing module is specifically used to: when the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, determine the first bus target value of the resonant converter according to the voltage of the input bus and the real-time operating frequency of the resonant converter; and determine the second bus target value of the non-resonant converter according to the voltage of the output bus; or, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, determine the first bus target value of the resonant converter according to the voltage of the output bus and the real-time operating frequency of the resonant converter; and determine the second bus target value of the non-resonant converter according to the voltage of the input bus; Determining a first bus target value of the resonant converter includes: acquiring a real-time operating frequency and a resonant frequency of the resonant converter; inputting the real-time operating frequency and the resonant frequency into a closed-loop control system to determine a resonant regulation voltage; when the first DC converter is a resonant converter and the second DC converter is a non-resonant converter, determining the first bus target value of the resonant converter according to the resonant regulation voltage and the voltage of the input bus; or, when the first DC converter is a non-resonant converter and the second DC converter is a resonant converter, determining the first bus target value of the resonant converter according to the resonant regulation voltage and the voltage of the output bus.

8. A two-stage DC converter, characterized in that: include: A first DC converter, a second DC converter and an intermediate bus voltage regulating device as claimed in claim 7; Among them, the first DC converter is connected to the input bus, the second DC converter is connected to the output bus, the first DC converter and the second DC converter are connected through an intermediate bus, one of the first DC converter and the second DC converter is a resonant converter, and the other is a non-resonant converter; the intermediate bus voltage adjustment device is connected to the first DC converter and the second DC converter.

9. A computer 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, the intermediate bus voltage adjustment method described in any one of claims 1 to 6 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the intermediate bus voltage adjustment method according to any one of claims 1 to 6 is implemented.

11. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the intermediate bus voltage adjustment method according to any one of claims 1 to 6 is implemented.

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