Control methods, devices, equipment, systems, and photovoltaic chargers for dual active bridge converters
By monitoring the voltage transfer ratio and measured data of the dual active bridge converter, and controlling the dual active bridge converter by adopting linear conversion or maintaining the initial phase shift parameters, the singularity problem in the phase shift angle calculation is solved, and the stable and safe operation of the converter is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENZHEN POWEROAK NEWENER CO LTD
- Filing Date
- 2026-07-01
- Publication Date
- 2026-07-31
AI Technical Summary
In existing technologies, the phase shift angle calculation of dual active bridge converters has a mathematical singularity, which causes the phase shift angle to tend to infinity or a sign jump, resulting in current distortion and hardware damage.
By acquiring measured data from the dual active bridge converter, monitoring whether the voltage transfer ratio meets the preset distortion adjustment conditions, and using linear conversion or maintaining the initial phase shift parameters, a drive signal is generated to control the converter's operation, thereby eliminating mathematical singularities and current distortion.
It effectively eliminates mathematical singularities and current distortions, ensuring the hardware safety and stability of the dual active bridge converter, reducing electromagnetic interference, and preventing hardware damage.
Smart Images
Figure CN122495864A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of converter control technology, and in particular to a control method, apparatus, device, system, and photovoltaic charger for a dual active bridge converter. Background Technology
[0002] Dual Active Bridge (DAB) converters are widely used in high-power photovoltaic charging, energy storage systems, and electric vehicle charging stations due to their electrical isolation, bidirectional power transfer capabilities, and ease of implementing zero-voltage switching (ZVS). In the parameter determination strategy of DAB converters, to reduce current stress and expand the soft-switching range, triple-phase-shift (TPS) or extended-phase-shift (EPS) control is typically employed. The minimum effective current value or minimum return power is usually used as the optimization objective, and a mathematical model is established to calculate the optimal phase shift angle to implement triple-phase-shift or extended-phase-shift control. While the optimal phase shift angle calculated by the mathematical model can achieve optimal efficiency for the DAB converter, the calculated phase shift angle may contain mathematical singularities, causing the phase shift angle to tend towards infinity or experience sign jumps, leading to current distortion and hardware damage to the DAB converter. Therefore, how to control the phase shift angle of a dual active bridge converter to eliminate mathematical singularities and thus avoid the phase shift angle from tending to infinity or experiencing sign jumps is a technical problem that needs to be solved. Summary of the Invention
[0003] This application provides a control method, apparatus, device, system, and photovoltaic charger for a dual active bridge converter, aiming to solve the technical problem of how to control the phase shift angle of a dual active bridge converter to eliminate mathematical singularities and thus avoid the phase shift angle from tending to infinity or experiencing sign jumps.
[0004] A control method for a dual active bridge converter includes: Obtain the measured data of the dual active bridge converter; Based on the measured data, the voltage transfer ratio and initial phase shift parameters of the dual active bridge converter are determined; When the voltage transmission ratio meets the preset distortion adjustment conditions, the initial phase shift parameters are linearly transformed to determine the target phase shift parameters; When the voltage transmission ratio does not meet the preset distortion adjustment condition, the initial phase shift parameter is determined as the target phase shift parameter; A drive signal is generated based on the target phase shift parameters to control the operation of the dual active bridge converter; The preset distortion adjustment condition is used to evaluate the current distortion that occurs in the dual active bridge converter.
[0005] Preferably, the preset distortion adjustment condition includes the absolute value of the difference between the voltage transmission ratio and 1 being less than a preset threshold.
[0006] Preferably, the measured data includes input voltage, output voltage, and output current; The determination of the voltage transfer ratio and initial phase shift parameters of the dual active bridge converter based on the measured data includes: The voltage transfer ratio of the dual active bridge converter is determined based on the input voltage and the output voltage. Based on the output voltage and the output current, determine the theoretical power of the dual active bridge converter; Based on the voltage transfer ratio and theoretical power of the dual active bridge converter, a target parameter determination strategy is determined, and the initial phase shift parameters are determined according to the target parameter determination strategy.
[0007] Preferably, the strategy for determining the target parameters based on the voltage transfer ratio and theoretical power of the dual active bridge converter includes: The preset parameter determination strategy that matches the voltage transfer ratio and theoretical power of the dual active bridge converter is determined as the target parameter determination strategy. Each of the preset parameter determination strategies includes the primary side inward phase angle formula, the reference phase angle formula, the secondary side inward phase angle formula, and the primary and secondary side outward phase angle formula; The formula for the primary side inward phase shift angle is used to determine the primary side inward phase shift angle based on the feedforward power and the voltage transmission ratio; the feedforward power is determined based on the output voltage, the output current, and a preset feedforward value. The reference phase shift angle formula is used to determine the reference phase shift angle based on the reference power and the voltage transmission ratio; The formula for the inner phase shift angle of the secondary side is used to determine the inner phase shift angle of the secondary side based on the voltage transmission ratio and the inner phase shift angle of the primary side; The formula for the outer phase shift angle of the primary and secondary sides is used to determine the outer phase shift angle of the primary and secondary sides based on the reference phase shift angle, the inner phase shift angle of the primary side, and the inner phase shift angle of the secondary side.
[0008] Preferably, the initial phase shift parameters include the initial primary side inner phase shift angle, the initial secondary side inner phase shift angle, and the initial primary and secondary side outer phase shift angles; The step of performing a linear transformation on the initial phase shift parameters to determine the target phase shift parameters includes: The initial primary side inward phase angle is linearly transformed using a linear transformation formula to determine the target primary side inward phase angle. The initial secondary side inward phase angle is then determined as the target secondary side inward phase angle, and the initial primary and secondary side outward phase angle is determined as the target primary and secondary side outward phase angle. Wherein, the linear transformation formula is , The phase angle is shifted inward from the original side of the target. The initial phase angle of the primary and secondary sides shifted outward. Let be the initial phase shift angle of the secondary side, and k be the voltage transfer ratio.
[0009] Preferably, the step of using a linear transformation formula to linearly transform the initial primary side inward phase shift angle to determine the target primary side inward phase shift angle includes: The initial primary side inward phase shift angle is linearly transformed using the aforementioned linear transformation formula to determine the linear primary side inward phase shift angle; The phase shift angle of the linear primary side is limited to determine the phase shift angle of the target primary side, so that the value of the phase shift angle of the target primary side is between 0 and 0.5.
[0010] A control device for a dual active bridge converter, comprising: The measured data acquisition module is used to acquire measured data of the dual active bridge converter; The measured data processing module determines the voltage transfer ratio and initial phase shift parameters of the dual active bridge converter based on the measured data. The first target phase shift parameter determination module is used to perform a linear transformation on the initial phase shift parameter to determine the target phase shift parameter when the voltage transfer ratio meets the preset distortion adjustment condition; the preset distortion adjustment condition is a condition used to evaluate the occurrence of current distortion in the dual active bridge converter. The second target phase shift parameter determination module is used to determine the initial phase shift parameter as the target phase shift parameter when the voltage transmission ratio does not meet the preset distortion adjustment condition; The drive control module generates a drive signal based on the target phase shift parameters to control the operation of the dual active bridge converter.
[0011] A control device includes a processor and a memory, wherein, Memory, used to store computer programs; The processor is used to execute the program stored in the memory to implement the control method of the dual active bridge converter described above.
[0012] A control system includes a dual active bridge converter and a control device, wherein the control device is connected to the dual active bridge converter and is used to control the dual active bridge converter to perform the control method of the dual active bridge converter described above.
[0013] A photovoltaic charger includes a photovoltaic module, a battery, and the aforementioned control system. The control system is connected to the photovoltaic module and the battery respectively, and is used to execute the aforementioned control method of a dual active bridge converter to control the dual active bridge converter to operate and transmit the electrical energy generated by the photovoltaic module to the battery so that the battery can supply power to the load.
[0014] The control method, apparatus, equipment, system, and photovoltaic charger for the dual active bridge converter provided in this embodiment determine the target phase-shift parameters for stable operation of the dual active bridge converter by monitoring whether the voltage transfer ratio meets the preset distortion adjustment conditions and using different methods. When the voltage transfer ratio meets the preset distortion adjustment conditions, the initial phase-shift parameters are linearly transformed to determine the target phase-shift parameters, thereby eliminating mathematical singularities and current distortion, significantly reducing electromagnetic interference, effectively protecting the hardware of the dual active bridge converter from damage, and ensuring the safety and stability of the dual active bridge converter's operation. Attached Figure Description
[0015] Figure 1 This is a circuit diagram of a dual active bridge converter provided in one embodiment of this application; Figure 2 This is a schematic diagram of a current distortion waveform provided in an embodiment of this application; Figure 3 This is a schematic diagram of another current distortion waveform provided in one embodiment of this application; Figure 4 This is a schematic diagram of another current distortion waveform provided in one embodiment of this application; Figure 5 This is a schematic diagram of another current distortion waveform provided in one embodiment of this application; Figure 6 This is a flowchart of a control method for a dual active bridge converter provided in an embodiment of this application; Figure 7 This is another flowchart of a control method for a dual active bridge converter provided in an embodiment of this application; Figure 8 This is another flowchart of a control method for a dual active bridge converter provided in an embodiment of this application; Figure 9 This is a schematic diagram of the control device for a dual active bridge converter provided in an embodiment of this application; Figure 10 This is a structural diagram of a control device provided in an embodiment of this application; Figure 11 This is a current waveform diagram after eliminating mathematical singularities and current distortion, provided in an embodiment of this application. Detailed Implementation
[0016] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0017] like Figure 1 As shown, the dual active bridge converter (DAB) in this embodiment is an isolated converter topology consisting of two full bridges on the primary and secondary sides and a high-frequency transformer.
[0018] This application provides a control method for a dual active bridge converter, used to control... Figure 1 The phase shift angle of the dual active bridge converter (DAB) is controlled to eliminate mathematical singularities generated during triple phase shift control or extended phase shift control, thereby preventing the phase shift angle from tending to infinity or causing sign jumps, and ensuring the hardware safety performance of the DAB. Triple phase shift control is a parameter determination strategy for a DAB, containing three control degrees of freedom: the primary side inner phase shift angle... Secondary side inward shift phase angle Phase angle of the original secondary side shift Extended phase-shift control is a parameter determination strategy for dual active bridge converters (DABs) that adds in-bridge phase shift to the single phase-shift control, and includes two degrees of freedom: the phase shift angle within the primary side. Phase angle of the original secondary side shift Single Phase Shift (SPS) refers to control that utilizes only the phase shift angle of the primary and secondary sides. A control strategy that controls power and keeps the duty cycle of the primary and secondary sides fixed at 50%.
[0019] In the triple phase-shift control or extended phase-shift control process of a dual active bridge converter, when the voltage transfer ratio is close to 1, a mathematical singularity occurs, causing the phase shift angle to tend towards infinity or abruptly change, thus leading to current distortion. For example... Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown in the schematic diagram of the current distortion waveform, when the voltage transfer ratio is close to 1, it will cause the dual active bridge converter to produce asymmetrical current distortion. Figure 2 , Figure 3 and Figure 4 The sharp peak circled in the middle, and Figure 5 (The spikes in the current). This asymmetrical current distortion not only destroys the soft-switching characteristics of the dual active bridge converter, but also generates severe electromagnetic interference, causing the power devices of the dual active bridge converter to fail, resulting in irreversible damage to the dual active bridge converter.
[0020] The control method for the dual active bridge converter provided in this embodiment acquires the measured data of the dual active bridge converter; based on the measured data, it determines the voltage transfer ratio and initial phase shift parameters of the dual active bridge converter; when the voltage transfer ratio meets the preset distortion adjustment conditions, it performs a linear transformation on the initial phase shift parameters to determine the target phase shift parameters; when the voltage transfer ratio does not meet the preset distortion adjustment conditions, it determines the initial phase shift parameters as the target phase shift parameters; based on the target phase shift parameters, it generates a drive signal to control the operation of the dual active bridge converter, thereby controlling the phase shift angle combination corresponding to the dual active bridge converter, eliminating the mathematical singularities generated during triple phase shift control or extended phase shift control, thus avoiding the phase shift angle from tending to infinity or experiencing sign jumps, thereby avoiding current distortion and electromagnetic interference, and ensuring the hardware safety performance of the dual active bridge converter.
[0021] In one embodiment, such as Figure 6 As shown, a control method for a dual active bridge converter is provided, through... Figure 10 The control device shown executes the control method of the dual active bridge converter in this embodiment, and controls... Figure 1 The phase shift angle of the dual active bridge converter is controlled by the following steps: S601: Obtain the measured data of the dual active bridge converter; S602: Based on measured data, determine the voltage transfer ratio and initial phase shift parameters of the dual active bridge converter; S603: When the voltage transfer ratio meets the preset distortion adjustment conditions, the initial phase shift parameters are linearly transformed to determine the target phase shift parameters; S604: When the voltage transfer ratio does not meet the preset distortion adjustment conditions, the initial phase shift parameter is determined as the target phase shift parameter; S605: Generates a drive signal based on the target phase shift parameters to control the operation of the dual active bridge converter; The preset distortion adjustment condition is used to evaluate the current distortion that occurs in the dual active bridge converter.
[0022] Among them, the measured data refers to the data corresponding to the dual active bridge converter monitored in real time.
[0023] As an example, in step S601, the control device acquires the measured data of the dual active bridge converter. In this example, the measured data includes, but is not limited to, voltage and current data obtained by monitoring the dual active bridge converter, used to determine the voltage transfer ratio and phase shift parameters of the dual active bridge converter.
[0024] In this context, the voltage transfer ratio refers to the ratio between the secondary-side voltage (referred to the primary side) and the primary-side input voltage in a dual active bridge converter. Initial phase-shift parameters refer to the unadjusted phase-shift parameters. These parameters include, but are not limited to, the primary-side inner phase-shift angle, the secondary-side inner phase-shift angle, and the primary-secondary-side outer phase-shift angle. For example... Figure 1 As shown, The phase shift angle, denoted as the primary side inward shift angle, is used to characterize the phase difference of the drive signal between the switching transistors of the upper half-bridge and the lower half-bridge on the primary side. The phase angle between the primary and secondary sides is denoted as the phase angle of the primary and secondary sides, and is used to characterize the phase difference between the overall waveform of the primary side and the overall waveform of the secondary side. The phase shift angle, denoted as the inner phase angle of the secondary side, is used to characterize the phase difference of the drive signal between the switching transistors of the upper half-bridge and the lower half-bridge of the secondary side.
[0025] As an example, in step S602, the control device determines the voltage value of the secondary side voltage referred to the primary side and the input voltage of the primary side based on the measured data of the dual active bridge converter. The ratio between the voltage value of the secondary side voltage referred to the primary side and the input voltage of the primary side is determined as the voltage transfer ratio. The control device also determines the phase shift parameters of the dual active bridge converter based on the measured data, and uses these phase shift parameters as the initial phase shift parameters. In this example, the control device determines the corresponding primary side inner phase shift angle, secondary side inner phase shift angle, and primary-secondary side outer phase shift angle between the primary and secondary sides based on the measured data of the dual active bridge converter. The primary side inner phase shift angle, secondary side inner phase shift angle, and primary-secondary side outer phase shift angle between the primary and secondary sides determined based on the measured data are used as the initial phase shift parameters.
[0026] As an example, in step S603, the control device judges the magnitude of the voltage transfer ratio and evaluates whether the voltage transfer ratio meets the preset distortion adjustment condition. When it is determined that the voltage transfer ratio meets the preset distortion adjustment condition, the initial phase shift parameter is linearly transformed to obtain the target phase shift parameter, so as to eliminate the mathematical singularity corresponding to the initial phase shift parameter and the current distortion phenomenon of the dual active bridge converter, and ensure the safety performance of the dual active bridge converter. Understandably, when the voltage transfer ratio meets the preset distortion adjustment condition, it indicates that when the dual active bridge converter operates at this voltage transfer ratio, it will generate a mathematical singularity that causes the initial phase shift parameter to tend to infinity or jump, and produce current distortion. At this time, it is necessary to adjust the initial phase shift parameter to obtain the target phase shift parameter that can eliminate the mathematical singularity and current distortion, so as to ensure that the hardware of the dual active bridge converter is not damaged. Therefore, the initial phase shift parameter is linearly transformed to determine the target phase shift parameter. In this example, when the voltage transfer ratio meets the preset distortion adjustment conditions, at least one of the primary side inner phase shift angle, the secondary side inner phase shift angle, and the primary and secondary side outer phase shift angles between the primary and secondary sides is linearly transformed to obtain the target phase shift parameters after linear transformation.
[0027] As an example, in step S604, the control device judges the magnitude of the voltage transfer ratio and evaluates whether the voltage transfer ratio meets the preset distortion adjustment condition. If it is determined that the voltage transfer ratio does not meet the preset distortion adjustment condition, the initial phase shift parameter is determined as the target phase shift parameter. Understandably, when the voltage transfer ratio does not meet the preset distortion adjustment condition, it indicates that when the dual active bridge converter operates at that voltage transfer ratio, it will not produce a mathematical singularity that causes the initial phase shift parameter to tend towards infinity or abruptly change, nor will it produce current distortion. In this case, there is no need to adjust the initial phase shift parameter. Controlling the dual active bridge converter according to the initial phase shift parameter can ensure that the hardware of the dual active bridge converter is not damaged. Therefore, determining the initial phase shift parameter as the target phase shift parameter allows for convenient and quick control of the dual active bridge converter.
[0028] Among them, the driving signal refers to the signal used to drive the switching transistors in the H-bridge of the dual active bridge converter.
[0029] As an example, in step S605, under the control of the target phase-shift parameter, the control device generates a drive signal corresponding to the target phase-shift parameter, controlling the switching transistors in the dual active bridge converter to operate, thereby eliminating mathematical singularities and current distortions, and effectively protecting the hardware of the dual active bridge converter from damage. Figure 11 The image shown is a current waveform after eliminating mathematical singularities and current distortion. Figure 11 It can be seen that, under the control of the target phase-shifting parameters, the current spikes of the dual active bridge converter are eliminated, and the switching transistors of the dual active bridge converter no longer bear excessive peak current, maintaining good soft-switching characteristics under all operating conditions. In actual measurements, the peak temperature of the switching transistors in the dual active bridge converter is reduced from above 110 degrees Celsius to below 85 degrees Celsius, completely eliminating the risk of thermal runaway.
[0030] For example, if the target phase shift parameter is the primary side inward phase shift angle after eliminating mathematical singularities, the control device generates a corresponding drive signal based on this angle to control the switching transistors in the dual active bridge converter, thereby eliminating current distortion and ensuring the converter's operational stability. As another example, the control device generates corresponding drive signals based on the primary side inward phase shift angle, the secondary side inward phase shift angle, and the primary-secondary side outward phase shift angle after eliminating mathematical singularities, controlling the switching transistors in the dual active bridge converter to eliminate current distortion and ensure its operational stability.
[0031] In this embodiment, by monitoring whether the voltage transfer ratio meets the preset distortion adjustment conditions, different methods are used to determine the target phase shift parameters for controlling the stable operation of the dual active bridge converter. When the voltage transfer ratio meets the preset distortion adjustment conditions, the initial phase shift parameters are linearly transformed to determine the target phase shift parameters, thereby eliminating mathematical singularities and current distortion, significantly reducing electromagnetic interference, effectively protecting the hardware of the dual active bridge converter from damage, and ensuring the safety and stability of the dual active bridge converter's operation.
[0032] In one embodiment, the preset distortion adjustment condition includes the absolute value of the difference between the voltage transfer ratio and 1 being less than a preset threshold.
[0033] The preset threshold refers to a relatively small preset value used to evaluate the magnitude of the absolute value corresponding to the difference between the voltage transfer ratio and 1.
[0034] As an example, the control device determines whether the absolute value of the difference between the voltage transfer ratio and 1 is less than a preset threshold. If the absolute value is less than the preset threshold, the voltage transfer ratio is deemed to meet a preset distortion adjustment condition. If the absolute value is not less than the preset threshold, the voltage transfer ratio is deemed not to meet the preset distortion adjustment condition. Understandably, the preset threshold is a relatively small value. If the absolute value is less than the preset threshold, it indicates that the voltage transfer ratio is approximately 1. In this case, if the dual active bridge converter transmits voltage with this voltage transfer ratio (approximately 1), it will produce a mathematical singularity that causes the initial phase shift parameter to tend towards infinity or abruptly change, thus resulting in current distortion. If the absolute value is not less than the preset threshold, it indicates that the difference between the voltage transfer ratio and 1 is relatively large. In this case, if the dual active bridge converter transmits voltage with this voltage transfer ratio (approximately 1), it will not produce a mathematical singularity that causes the initial phase shift parameter to tend towards infinity or abruptly change, nor will it produce current distortion.
[0035] In this embodiment, the absolute value of the difference between the voltage transfer ratio and 1 is determined to accurately determine whether the dual active bridge converter will produce mathematical singularities and current distortions that cause the initial phase shift parameters to tend towards infinity or jump when operating at this voltage transfer ratio. This allows for timely adjustment of the initial phase shift parameters to eliminate mathematical singularities and current distortions, ensuring the stability of the dual active bridge converter.
[0036] In one embodiment, the measured data includes input voltage, output voltage, and output current; Here, input voltage refers to the voltage on the primary side of the dual active bridge converter. Output voltage refers to the voltage on the secondary side of the dual active bridge converter. Output current refers to the current output from the secondary side of the dual active bridge converter.
[0037] In one embodiment, such as Figure 7 As shown, step S602, which involves determining the voltage transfer ratio and initial phase shift parameters of the dual active bridge converter based on measured data, includes: S701: Determine the voltage transfer ratio of the dual active bridge converter based on the input voltage and output voltage; S702: Determine the theoretical power of the dual active bridge converter based on the output voltage and output current; S703: Based on the voltage transfer ratio and theoretical power of the dual active bridge converter, determine the target parameter determination strategy, and determine the initial phase shift parameters according to the target parameter determination strategy.
[0038] As an example, in step S701, the control device, based on the turns ratio n between the number of turns of the transformer primary winding and the number of turns of the transformer secondary winding pre-stored in the system database, adjusts the input voltage monitored in real time. and output voltage The voltage transfer ratio k of the dual active bridge converter is determined through processing. In this example, the voltage transfer ratio k is: .
[0039] Theoretical power refers to the power that the dual active bridge converter needs to achieve under the measured output voltage and output current conditions.
[0040] As an example, in step S702, the control device outputs voltage. and output current The product of these two values is used to determine the theoretical power of the dual active bridge converter. That is, the theoretical power P of the dual active bridge converter is: .
[0041] The target parameter determination strategy refers to the strategy used to determine the initial phase shift parameters. Understandably, when using triple phase shift control (TPS) or extended phase shift control (EPS) for loop control of a dual active bridge converter, different voltage transfer ratios and different theoretical power require different strategies to determine the initial phase shift parameters; this strategy is the target parameter determination strategy.
[0042] As an example, in step S703, the control device queries the target parameter determination strategy pre-stored in the system database that has a mapping relationship with the range of voltage transfer ratio and theoretical power of the dual active bridge converter, according to the range of voltage transfer ratio and theoretical power of the dual active bridge converter. Using the target parameter determination strategy, the initial phase shift parameters corresponding to the dual active bridge converter operating under the voltage transfer ratio and theoretical power are determined.
[0043] In this embodiment, a target parameter determination strategy corresponding to the voltage transfer ratio and theoretical power of the dual active bridge converter is determined. Based on the target parameter determination strategy, the initial phase shift parameters are accurately determined so that subsequent adjustments to the initial phase shift parameters can be made to accurately eliminate mathematical singularities and current distortions.
[0044] In one embodiment, step S703, namely determining the target parameter determination strategy based on the voltage transfer ratio and theoretical power of the dual active bridge converter, includes: The preset parameter determination strategy that matches the voltage transfer ratio and theoretical power of the dual active bridge converter is determined as the target parameter determination strategy. Each preset parameter determination strategy includes the primary side inward phase angle formula, the reference phase angle formula, the secondary side inward phase angle formula, and the primary and secondary side outward phase angle formula; The formula for the primary-side inward phase shift angle is used to determine the primary-side inward phase shift angle based on the feedforward power and voltage transmission ratio; the feedforward power is determined based on the output voltage, output current, and preset feedforward value. The reference phase shift angle formula is used to determine the reference phase shift angle based on the reference power and voltage transfer ratio; The formula for the inner phase shift angle of the secondary side is used to determine the inner phase shift angle of the secondary side based on the voltage transfer ratio and the inner phase shift angle of the primary side. The formula for the outer phase shift angle of the primary and secondary sides is used to determine the outer phase shift angle of the primary and secondary sides based on the reference phase shift angle, the inner phase shift angle of the primary side, and the inner phase shift angle of the secondary side.
[0045] Among them, the preset parameter determination strategy refers to the parameter determination strategy that is pre-stored and matches the voltage transmission ratio and theoretical power.
[0046] As an example, Table 1 shows the mapping relationship table for voltage transfer ratio, theoretical power, and preset parameter determination strategies pre-stored in the system database of the control equipment. After determining the voltage transfer ratio and theoretical power of the dual active bridge converter, the control equipment determines the range of the voltage transfer ratio and the range of the theoretical power according to the mapping relationship table in Table 1. The parameter determination formula that matches the range of the voltage transfer ratio and the range of the theoretical power in the mapping relationship table is then used as the target parameter determination strategy. For example, if the voltage transfer ratio k > 1, the range of theoretical power is 0 ≤ P < 1. The strategy for determining the target parameters is: shift the phase angle inward from the original side. Reference phase shift angle Secondary side shifted inward phase angle Phase angle shifted outward from the original secondary side .
[0047] Furthermore, as shown in Table 1, the mapping relationship table corresponding to the voltage transfer ratio, theoretical power, and preset parameter determination strategies includes four preset parameter determination strategies. The first preset parameter determination strategy is when the voltage transfer ratio k > 1 and the theoretical power range is 0 ≤ P < 1. The second preset parameter determination strategy is based on a voltage transfer ratio k > 1 and a theoretical power range of [missing information]. The parameter determination strategy when ≤P≤1, the third preset parameter determination strategy is when the voltage transfer ratio k<1 and the theoretical power range is 0≤P<1. The fourth preset parameter determination strategy is based on a voltage transfer ratio k < 1 and a theoretical power range of [missing information]. Parameter determination strategies when P ≤ 1. Each preset parameter determination strategy includes the primary side inward phase shift formula, the reference phase shift formula, the secondary side inward phase shift formula, and the primary and secondary side outward phase shift formula. For example, if the voltage transfer ratio k > 1, the theoretical power range is 0 ≤ P < 1. The preset parameter determination strategy includes the original side inward phase angle formula. The formula for the reference phase shift angle Secondary side inward shift phase angle formula The formula for the phase angle shift of the primary and secondary sides. .in, The feedforward power is determined based on the output voltage, output current, and a preset feedforward value. The preset feedforward value refers to a preset power factor constant. This is the reference power, which is the preset value.
[0048] As shown in Table 1, the formula for the primary side inward phase shift angle is used for feedforward power. and voltage transfer ratio Determine the phase angle of the original side's inward shift. The reference phase shift angle formula is used for reference power. and voltage transfer ratio Determine the reference phase shift angle The formula for the secondary side inward phase shift angle is used based on the voltage transfer ratio. and the phase angle of the original side shift Determine the phase angle of the secondary side inward shift. The formula for the primary and secondary side external phase shift angle is used based on the reference phase shift angle. Phase angle shifted inward from the original side and the phase angle of the inner shift of the secondary side Determine the phase angle of the primary secondary side shift. .
[0049] Table 1 In one embodiment, the initial phase shift parameters include the initial primary side inner phase shift angle, the initial secondary side inner phase shift angle, and the initial primary and secondary side outer phase shift angles; The initial primary side inward phase shift angle refers to the initial primary side inward phase shift angle determined by the strategy based on the target parameters. The initial secondary side inward phase shift angle refers to the initial secondary side inward phase shift angle determined by the strategy based on the target parameters. The initial primary and secondary side outward phase shift angles refer to the initial primary and secondary side outward phase shift angles determined by the strategy based on the target parameters.
[0050] In one embodiment, step S603, which involves performing a linear transformation on the initial phase-shifting parameters to determine the target phase-shifting parameters, includes: S6031: The initial primary side inward phase angle is linearly transformed using a linear transformation formula to determine the target primary side inward phase angle, and the initial secondary side inward phase angle is determined as the target secondary side inward phase angle. The initial primary and secondary side outward phase angles are then determined as the target primary and secondary side outward phase angles. The linear transformation formula is as follows: , The phase angle is shifted inward from the original side of the target. The initial phase angle of the primary and secondary sides shifted outward. Let be the initial phase shift angle of the secondary side, and k be the voltage transfer ratio.
[0051] The target primary side inward phase shift angle refers to the inward phase shift angle of the primary side after eliminating mathematical singularities. The target secondary side inward phase shift angle refers to the inward phase shift angle of the secondary side after eliminating mathematical singularities. The target primary and secondary side outward phase shift angle refers to the outward phase shift angle of the primary and secondary sides after eliminating mathematical singularities.
[0052] As an example, in step S6031, the control device determines the initial secondary side inward phase shift angle. Initial primary and secondary side outward shift phase angle After the voltage transfer ratio k, a linear transformation formula is used. The initial secondary side shift phase angle Initial primary and secondary side outward shift phase angle A linear transformation is performed on the voltage transfer ratio k to obtain the primary side inward phase shift angle after linear transformation. This linearly transformed primary side inward phase shift angle is then determined as the target primary side inward phase shift angle. The control device will shift the initial secondary side inward by a phase angle. Determined as the target secondary side inward phase angle Shift the initial primary and secondary sides outward by phase angle The phase angle of the target primary and secondary sides is determined to be shifted outward. .
[0053] Understandably, the phase shift angle inside the primary side of the dual active bridge converter is the initial phase shift angle inside the primary side. At that time, the primary-side H-bridge of the dual active bridge converter undergoes an initial primary-side phase shift angle. After phase shift, the effective duty cycle of the output voltage With (1- Proportional to, that is The effective voltage of the secondary H-bridge of a dual active bridge converter referred to the primary side. With (1- Proportional to, that is To minimize the current stress in the dual active bridge converter, it is necessary to... and As equal as possible, that is Due to voltage conversion ratio So, voltage conversion ratio The reciprocal of m is , ,therefore, Equivalent to Further equivalent to ,Right now Since k is near 1, and ,So ,but .because ,So, The above formula This represents the ideal state of a dual active bridge converter under no-load (or light-load) conditions. Here, no-load or light-load conditions refer to the state where the output power of the dual active bridge converter is relatively low. In practical engineering, as the load increases, the phase angle of the primary and secondary sides shifts outward. As the power increases, the dual active bridge converter needs to transmit more power. According to the minimum current stress theory, when the power increases, the primary side internal phase shift angle should be reduced. and the phase angle of the inner shift of the secondary side This allows the waveform to revert to an SPS rectangular wave. Therefore, to ensure the accuracy of the linear transformation of the initial primary side phase shift angle, and because of the primary side phase shift angle... Phase angle with the original secondary side shifted outward A negative correlation will result in " As a correction term for "regression SPS", for Perform accuracy corrections and determine Therefore, in this example, the target primary side is shifted inward by a phase angle. .
[0054] In this embodiment, the modified linear transformation formula is as follows: This method performs a linear transformation on the initial primary side's inward phase shift angle to accurately determine the target primary side's inward phase shift angle. Furthermore, this method can adjust the primary side's inward phase shift angle through simple addition and subtraction operations, eliminating mathematical singularities and current distortions. This significantly reduces the computational requirements of the control equipment, shortens execution time, and improves the system's dynamic response speed.
[0055] In one embodiment, such as Figure 8As shown, step S6031, which involves using a linear transformation formula to linearly transform the initial primary side inward phase shift angle to determine the target primary side inward phase shift angle, includes: S801: The initial primary side inward phase shift angle is linearly transformed using a linear transformation formula to determine the linear primary side inward phase shift angle; S802: Limit the phase shift angle of the linear primary side to determine the phase shift angle of the target primary side so that the value of the phase shift angle of the target primary side is between 0 and 0.5.
[0056] Among them, the linear primary side inward phase shift angle refers to the primary side inward phase shift angle obtained by directly using the linear transformation formula to linearly transform the initial primary side inward phase shift angle.
[0057] As an example, in step S801, the control device uses a phase shift angle determined in the initial secondary side. Initial primary and secondary side outward shift phase angle After the voltage transfer ratio k, a linear transformation formula is used. The initial secondary side shift phase angle Initial primary and secondary side outward shift phase angle A linear transformation is performed on the voltage transfer ratio k to obtain the primary side internal phase shift angle after linear transformation. The primary side internal phase shift angle after linear transformation is determined as the linear primary side internal phase shift angle.
[0058] As an example, in step S802, the control device determines the magnitude of the linear primary side inward phase shift angle. If the linear primary side inward phase shift angle is within the range of 0 to 0.5, it is determined as the target primary side inward phase shift angle. If the linear primary side inward phase shift angle exceeds the range of 0 to 0.5, it is subjected to amplitude limiting processing to obtain the target primary side inward phase shift angle with a value range of 0 to 0.5. In this example, the specific methods of amplitude limiting include, but are not limited to, truncation limiting, soft compression limiting, clipping limiting, and proportional limiting. Among them, truncation limiting refers to directly flattening the linear primary side inward phase shift angle with a value range exceeding 0 to 0.5 to obtain the target primary side inward phase shift angle with a value range of 0 to 0.5. Soft compression limiting refers to compressing the linear primary side inward phase shift angle with a value range exceeding 0 to 0.5 to between 0 and 0.5 by increasing the compression ratio as the amplitude increases. Clipping refers to directly cutting off the linear primary side inward phase angle whose value range exceeds 0 to 0.5. Proportional clipping refers to reducing the linear primary side inward phase angle as a whole according to a preset proportional coefficient to obtain a target primary side inward phase angle whose value range is 0 to 0.5.
[0059] In this embodiment, the phase shift angle of the linear primary side is limited to determine the target phase shift angle of the primary side, so that the value of the target phase shift angle of the primary side is between 0 and 0.5, so as to ensure that the dual active bridge converter does not exceed the charging limit under the target phase shift angle of the primary side, and avoid abnormal operation of the dual active bridge converter.
[0060] This application also provides a control device 90 for a dual active bridge converter. Please refer to [link / reference]. Figure 9 The system includes: a measured data acquisition module 910 for acquiring measured data of the dual active bridge converter; a measured data processing module 920 for determining the voltage transfer ratio and initial phase shift parameters of the dual active bridge converter based on the measured data; a first target phase shift parameter determination module 930 for performing a linear transformation on the initial phase shift parameters to determine the target phase shift parameters when the voltage transfer ratio meets the preset distortion adjustment conditions; the preset distortion adjustment conditions are used to evaluate the current distortion of the dual active bridge converter; a second target phase shift parameter determination module 940 for determining the initial phase shift parameters as the target phase shift parameters when the voltage transfer ratio does not meet the preset distortion adjustment conditions; and a drive control module 950 for generating a drive signal based on the target phase shift parameters to control the operation of the dual active bridge converter.
[0061] This application also provides a control device 100, please refer to... Figure 10 It includes a memory 1001 and a processor 1002, wherein the memory 1001 is used to store computer programs; the processor 1002 is used to execute the programs stored in the memory 1001 to implement the control method of the dual active bridge converter described in any embodiment of this application.
[0062] This application also provides a control system, including a dual active bridge converter and a control device. The control device is connected to the dual active bridge converter and is used to control the dual active bridge converter to execute the control method of the dual active bridge converter described in any embodiment of this application.
[0063] This application also provides a photovoltaic charger, including a photovoltaic module, a battery, and a control system as described in the above embodiments. The control system is connected to the photovoltaic module and the battery respectively, and is used to execute the control method of the dual active bridge converter described in any embodiment of this application through the control system, control the dual active bridge converter to work, and transmit the electrical energy generated by the photovoltaic module to the battery so that the battery can supply power to the load.
[0064] As an example, the control device in the control system is connected to a dual active bridge converter, such as... Figure 1 As shown, the primary input terminals BUS+ and BUS- of the dual active bridge converter are connected to the output terminals of the photovoltaic module, and the secondary output terminals BAT+ and BAT- of the dual active bridge converter are connected to the input terminals of the battery. This is used to transfer the electrical energy output by the photovoltaic module to the battery when the control equipment controls the dual active bridge converter to work, so that the battery can supply power to the load.
[0065] In this application, "multiple" refers to two or more.
[0066] In this application, unless otherwise expressly defined, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0067] The terms “first,” “second,” “third,” “fourth,” etc., in this application (if present) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.
[0068] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.
[0069] Unless otherwise specified, all steps in this application may be performed sequentially or randomly. For example, if the method includes steps A and B, it means that the method may include steps A and B performed sequentially, or it may include steps B and A performed sequentially. For example, if the method may also include step C, it means that step C may be added to the method in any order. For example, the method may include steps A, B, and C, or it may include steps A, C, and B, or it may include steps C, A, and B, etc.
[0070] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A control method for a dual active bridge converter, characterized in that, include: Obtain the measured data of the dual active bridge converter; Based on the measured data, the voltage transfer ratio and initial phase shift parameters of the dual active bridge converter are determined; When the voltage transmission ratio meets the preset distortion adjustment conditions, the initial phase shift parameters are linearly transformed to determine the target phase shift parameters; When the voltage transmission ratio does not meet the preset distortion adjustment condition, the initial phase shift parameter is determined as the target phase shift parameter; A drive signal is generated based on the target phase shift parameters to control the operation of the dual active bridge converter; The preset distortion adjustment condition is used to evaluate the current distortion that occurs in the dual active bridge converter.
2. The control method for a dual active bridge converter according to claim 1, characterized in that, The preset distortion adjustment conditions include the absolute value of the difference between the voltage transmission ratio and 1 being less than a preset threshold.
3. The control method for a dual active bridge converter according to claim 1, characterized in that, The measured data includes input voltage, output voltage, and output current; The determination of the voltage transfer ratio and initial phase shift parameters of the dual active bridge converter based on the measured data includes: The voltage transfer ratio of the dual active bridge converter is determined based on the input voltage and the output voltage. Based on the output voltage and the output current, determine the theoretical power of the dual active bridge converter; Based on the voltage transfer ratio and theoretical power of the dual active bridge converter, a target parameter determination strategy is determined, and the initial phase shift parameters are determined according to the target parameter determination strategy.
4. The control method for a dual active bridge converter according to claim 3, characterized in that, The strategy for determining the target parameters based on the voltage transfer ratio and theoretical power of the dual active bridge converter includes: The preset parameter determination strategy that matches the voltage transfer ratio and theoretical power of the dual active bridge converter is determined as the target parameter determination strategy. Each of the preset parameter determination strategies includes the primary side inward phase angle formula, the reference phase angle formula, the secondary side inward phase angle formula, and the primary and secondary side outward phase angle formula; The formula for the primary side inward phase shift angle is used to determine the primary side inward phase shift angle based on the feedforward power and the voltage transmission ratio; the feedforward power is determined based on the output voltage, the output current, and a preset feedforward value. The reference phase shift angle formula is used to determine the reference phase shift angle based on the reference power and the voltage transmission ratio; The formula for the inner phase shift angle of the secondary side is used to determine the inner phase shift angle of the secondary side based on the voltage transmission ratio and the inner phase shift angle of the primary side; The formula for the outer phase shift angle of the primary and secondary sides is used to determine the outer phase shift angle of the primary and secondary sides based on the reference phase shift angle, the inner phase shift angle of the primary side, and the inner phase shift angle of the secondary side.
5. The control method for a dual active bridge converter according to claim 1, characterized in that, The initial phase shift parameters include the initial primary side inward phase shift angle, the initial secondary side inward phase shift angle, and the initial primary and secondary side outward phase shift angles. The step of performing a linear transformation on the initial phase shift parameters to determine the target phase shift parameters includes: The initial primary side inward phase angle is linearly transformed using a linear transformation formula to determine the target primary side inward phase angle. The initial secondary side inward phase angle is then determined as the target secondary side inward phase angle, and the initial primary and secondary side outward phase angle is determined as the target primary and secondary side outward phase angle. Wherein, the linear transformation formula is , The phase angle is shifted inward from the original side of the target. The initial phase angle of the primary and secondary sides shifted outward. Let be the initial phase shift angle of the secondary side, and k be the voltage transfer ratio.
6. The control method for a dual active bridge converter according to claim 5, characterized in that, The step of using a linear transformation formula to linearly transform the initial primary side inward phase shift angle to determine the target primary side inward phase shift angle includes: The initial primary side inward phase shift angle is linearly transformed using the aforementioned linear transformation formula to determine the linear primary side inward phase shift angle; The phase shift angle of the linear primary side is limited to determine the phase shift angle of the target primary side, so that the value of the phase shift angle of the target primary side is between 0 and 0.
5.
7. A control device for a dual active bridge converter, characterized in that, include: The measured data acquisition module is used to acquire measured data of the dual active bridge converter; The measured data processing module determines the voltage transfer ratio and initial phase shift parameters of the dual active bridge converter based on the measured data. The first target phase shift parameter determination module is used to perform a linear transformation on the initial phase shift parameter to determine the target phase shift parameter when the voltage transfer ratio meets the preset distortion adjustment condition; the preset distortion adjustment condition is a condition used to evaluate the occurrence of current distortion in the dual active bridge converter. The second target phase shift parameter determination module is used to determine the initial phase shift parameter as the target phase shift parameter when the voltage transmission ratio does not meet the preset distortion adjustment condition; The drive control module generates a drive signal based on the target phase shift parameters to control the operation of the dual active bridge converter.
8. A control device, characterized in that, Including processor and memory, among which, Memory, used to store computer programs; A processor is used to execute a program stored in memory to implement the control method of the dual active bridge converter according to any one of claims 1-6.
9. A control system, characterized in that, The device includes a dual active bridge converter and a control device, wherein the control device is connected to the dual active bridge converter and is used to control the dual active bridge converter to perform the control method of the dual active bridge converter according to any one of claims 1 to 6.
10. A photovoltaic charger, characterized in that, The device includes a photovoltaic module, a battery, and the control system described in claim 9. The control system is connected to the photovoltaic module and the battery, respectively, and is used to execute the control method of the dual active bridge converter described in any one of claims 1 to 6 through the control system, control the dual active bridge converter to operate, and transmit the electrical energy generated by the photovoltaic module to the battery so that the battery supplies power to the load.