Control device based on voltage feed-forward control method and switching power supply

Abstract

The embodiment of the invention provides a control method based on voltage feed-forward. The control method comprises the following steps: acquiring a sampling signal of a DC bus voltage accessed to the input end of the power switch device; processing the sampling signal to separate a direct current component and an alternating current component of the sampling signal; generating an inverse proportion feedforward signal according to the direct current component and the alternating current component of the sampling signal; according to the inverse proportion feedforward signal and an output signal provided by the output end of the power switch device, a target control signal is generated, and the target control signal is used for controlling the duty ratio of the power switch device. According to the embodiment of the invention, the feedforward signal and the control system output target control signal are adopted, and a top-speed response path from disturbance generation to control action is established, so that the problems of poor real-time performance of the system and large power frequency noise of an output direct current end are solved.

Description

Technical Field

[0001] This application relates to the field of digital power supply design for precision signal detection, and specifically to a digital switching power supply based on a voltage feedforward control method. Background Technology

[0002] Digital switching power supplies play a crucial role in modern electronic devices, especially in applications requiring precise control and intelligence. These devices have extremely high requirements for power supply output quality and are highly sensitive to low-frequency noise in the output voltage, particularly noise within the power frequency range. In practical circuit applications, the noise present on the output DC bus is typically low-frequency noise with a fundamental frequency of 100 Hz or 120 Hz (single-phase system) and 300 Hz or 360 Hz (three-phase system). Although the operating frequency of the switching power supply itself can reach tens of kilohertz or even higher, and its output can suppress low-frequency noise to some extent, in noise-sensitive applications, this residual low-frequency ripple can still significantly affect device performance. For example, in the field of weak signal detection, it can lead to a reduced signal-to-noise ratio, posing a challenge to accurate signal detection.

[0003] In the design of digital switching power supplies, the control system typically comprises two parts: a control section and the main power stage. The DC-DC power stage is the controlled object, while the digital controller is responsible for implementing algorithmic control. It regulates the switching behavior of the power stage by generating duty cycle signals, thereby maintaining stable output voltage. The control stage commonly employs a negative feedback system, adjusting the duty cycle after a disturbance occurs to reduce its impact on the output voltage. For disturbances caused by input voltage variations, an input voltage feedforward control strategy can be introduced. This strategy aims to take corrective measures before the disturbance affects the output, improving system response speed and stability by predicting the outcome and compensating for anticipated disturbances in advance.

[0004] In related technologies, feedforward techniques typically sample and feedback the input voltage directly, but their attenuation effect on the AC component is insufficient. Furthermore, the output often relies on proportional-integral-derivative (PID) circuits to adjust the output voltage ripple, resulting in poor system real-time performance. Since low-frequency fluctuations in the input voltage are still limited by the system response bandwidth, it is difficult to effectively eliminate these interferences at the output voltage level. This problem is particularly prominent in high-voltage output applications. Summary of the Invention

[0005] This application provides a voltage feedforward-based control method to solve the problem of large output ripple caused by low-frequency fluctuations in input voltage in digital switching power supplies. Through a novel feedforward control algorithm, the power frequency ripple is significantly suppressed, improving the output quality of the power supply and the system response speed.

[0006] The voltage feedforward-based control method provided in this application includes: acquiring a sampling signal of the DC bus voltage connected to the input terminal of the power switching device; processing the sampling signal to separate the DC component and AC component of the sampling signal; generating an inverse proportional feedforward signal based on the DC component and AC component of the sampling signal; and generating a target control signal based on the inverse proportional feedforward signal and the output signal provided by the output terminal of the power switching device, wherein the target control signal is used to control the duty cycle of the power switching device.

[0007] In some embodiments, processing the sampled signal to separate the DC and AC components of the sampled signal includes: inputting the sampled signal into a proportional voltage divider circuit, sampling the output signal of the proportional voltage divider circuit using a digital control chip to obtain a first sampled signal; inputting the first sampled signal into a first filter to obtain the DC component of the sampled signal; inputting the first sampled signal into the first filter to obtain a second sampled signal; and subtracting the DC component of the sampled signal from the second sampled signal to obtain the AC component of the sampled signal.

[0008] In some embodiments, both the first filter and the second filter are moving average filters, wherein the averaging time of the first filter is set to be greater than twice the fundamental period of the AC component of the sampled signal, and the averaging time of the second filter is set to be less than half the fundamental period.

[0009] In some embodiments, generating an inverse proportional feedforward signal based on the DC and AC components of the sampled signal includes: proportionally amplifying and integrating the AC component of the sampled signal to obtain a third sampled signal; superimposing the third sampled signal with the DC component of the sampled signal to obtain a fourth sampled signal; and processing the fourth sampled signal through an inverse proportional function to output the inverse proportional feedforward signal.

[0010] In some embodiments, generating a target control signal based on the inverse proportional feedforward signal and the output signal provided by the output terminal of the power switching device, the target control signal being used to control the duty cycle of the power switching device, includes: determining a digital voltage loop and a digital current loop in the control loop based on the circuit topology connected to the power switching device; determining the output signal of the control loop based on the digital voltage loop and the digital current loop in the control loop, thereby determining the output signal provided by the output terminal of the power switching device; and performing a cross product calculation between the output signal of the control loop and the inverse proportional feedforward signal to generate the target control signal, the target control signal being used to control the duty cycle of the power switching device.

[0011] In some embodiments, determining the output signal of the control loop based on the digital voltage loop and the digital current loop in the control loop, so as to determine the output signal provided by the output terminal of the power switching device, includes: the operating modes of the digital voltage loop and the digital current loop are nested mode or competitive mode; in the digital voltage loop, a current reference signal is generated based on the error between the output voltage sample value and the reference voltage; in the digital current loop, the control loop output signal is determined based on the error between the inductor current sample value and the current reference signal.

[0012] In some embodiments, the control method further includes: generating a target control signal as a pulse width modulation signal based on the inverse proportional feedforward signal and the output signal provided by the output terminal of the power switching device; comparing the pulse width modulation signal with the carrier of the output signal to determine a target duty cycle; and controlling the duty cycle of the power switching device according to the target duty cycle.

[0013] The voltage feedforward-based control device provided in this application includes an acquisition module configured to acquire a sampled signal of the DC bus voltage connected to the input terminal of the power switching device; a first processing module configured to process the sampled signal to separate the DC component and AC component of the sampled signal; a second processing module configured to generate an inverse proportional feedforward signal based on the DC component and AC component of the sampled signal; and a third processing module configured to generate a target control signal based on the inverse proportional feedforward signal and the output signal provided by the output terminal of the power switching device, wherein the target control signal is used to control the duty cycle of the power switching device.

[0014] The voltage feedforward-based control device provided in this application embodiment further includes a pulse modulation module, configured to generate a target control signal as a pulse width modulation signal based on the inverse proportional feedforward signal and the output signal provided by the output terminal of the power switching device; compare the pulse width modulation signal with the carrier of the output signal to determine a target duty cycle; and control the duty cycle of the power switching device according to the target duty cycle.

[0015] The switching power supply provided in this application includes a power switching device; the voltage feedforward-based control device of the above embodiment is configured to control the duty cycle of the power switching device.

[0016] The voltage feedforward-based control method provided in this application includes: acquiring a sampling signal of the DC bus voltage connected to the input terminal of the power switching device; processing the sampling signal to separate the DC component and AC component of the sampling signal; generating an inverse proportional feedforward signal based on the DC component and AC component of the sampling signal; and generating a target control signal based on the inverse proportional feedforward signal and the output signal provided by the output terminal of the power switching device, wherein the target control signal is used to control the duty cycle of the power switching device.

[0017] The voltage feedforward-based control method provided in this application establishes an extremely fast response path from disturbance occurrence to control action by using the feedforward signal and the target control signal output by the control system, thereby solving the problem of poor system real-time performance. Ultimately, this series of coordinated steps enables the digital switching power supply to achieve unprecedented power frequency ripple suppression capability when facing low-frequency input voltage fluctuations, significantly improving output quality and system dynamic performance. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram illustrating the working steps of the voltage feedforward-based control method provided in the embodiments of this application.

[0020] Figure 2 A block diagram of a digital power supply structure provided for an embodiment of this application.

[0021] Figure 3 A block diagram of digital power control provided for an embodiment of this application. Detailed Implementation

[0022] In related technologies, feedforward techniques typically sample and feedback the input voltage directly, but their attenuation effect on the AC component is insufficient. Furthermore, the output often relies on proportional-integral-derivative (PID) circuits to adjust the output voltage ripple, resulting in poor system real-time performance. Since low-frequency fluctuations in the input voltage are still limited by the system response bandwidth, it is difficult to effectively eliminate these interferences at the output voltage level. This problem is particularly prominent in high-voltage output applications.

[0023] To address the aforementioned technical problems, this application provides a voltage feedforward-based control method, which aims to solve the problem of large output ripple caused by low-frequency fluctuations in input voltage in digital switching power supplies. Through a novel feedforward control algorithm, the power frequency ripple is significantly suppressed, improving the output quality of the power supply and the system response speed.

[0024] The embodiments of this application can be applied to digital switching power supplies, such as digital switching power supplies for precision control and intelligent equipment.

[0025] The following describes the voltage feedforward-based control method provided by the exemplary embodiments of this application in conjunction with the application scenarios described above and with reference to the accompanying drawings. It should be noted that the above application scenarios are only shown for the purpose of understanding the principles of this application, and the embodiments of this application are not limited in any way in this respect.

[0026] Figure 1 This diagram illustrates the working steps of the voltage feedforward-based control method provided in an embodiment of this application. Figure 1 As shown, the voltage feedforward-based control method provided in this application includes: Step 01: Obtain the sampling signal of the DC bus voltage connected to the input terminal of the power switching device; Step 02: Process the sampled signal to separate the DC and AC components of the sampled signal; Step 03: Generate an inverse proportional feedforward signal based on the DC and AC components of the sampled signal; Step 04: Generate a target control signal based on the inverse proportional feedforward signal and the output signal provided by the output terminal of the power switching device. The target control signal is used to control the duty cycle of the power switching device.

[0027] Specifically, the real-time monitoring and acquisition of the DC bus voltage at the input of the power switching device ensures that the sampled signal fully contains both the DC component and AC ripple information. The sampled signal is then processed to separate the DC and AC components. The algorithm then proceeds to the feedforward signal construction stage, generating an inversely proportional feedforward signal that accurately predicts and compensates for disturbances based on the separated AC and DC components. Instead of slow correction via a traditional PID loop, the inversely proportional feedforward signal directly determines the target control signal by combining it with the output signal of the dual-loop voltage and current control system at the power switching device's output. This controls the duty cycle of the power switching device, achieving rapid closed-loop control of the entire power system.

[0028] Thus, the voltage feedforward-based control method provided in this application establishes an extremely fast response path from disturbance occurrence to control action by using the feedforward signal and the target control signal output by the control system, thereby solving the problem of poor system real-time performance. Ultimately, this series of coordinated steps enables the digital switching power supply to achieve unprecedented power frequency ripple suppression capability when facing low-frequency input voltage fluctuations, significantly improving output quality and system dynamic performance.

[0029] Figure 2 This is a block diagram of a digital power supply structure provided for an embodiment of this application. Figure 2 As shown, in digital switching power supply design, the loop is divided into two parts: the control section and the main power stage. The DC / DC power stage is the controlled object of the digital switching power supply. The digital controller implements algorithmic control, and as the control stage of the digital switching power supply, it generates duty cycle signals to control the switching behavior of the power stage, thereby keeping the output power supply stable. The control stage introduces a negative feedback system, the purpose of which is to reduce the impact of disturbances on the output voltage. When a disturbance occurs, the control circuit generally does not know in advance the required duty cycle calibration amount, but for the adjustment of the input voltage, the duty cycle can be adjusted in real time through input voltage feedforward. Nevertheless, with current feedforward technology, low-frequency fluctuations in the input voltage are still limited by the system response bandwidth and cannot be well removed at the output voltage end, especially in the high-voltage output field, where the impact of low-frequency noise is particularly significant. If low-frequency noise is not handled properly, it will significantly affect the performance of the equipment, especially in the field of weak signal detection, reducing the signal-to-noise ratio and posing a challenge to the correct detection of signals.

[0030] The implementation of steps 01 to 04 above will be further described below based on digital switching power supply design.

[0031] First, in step 01, the DC bus voltage sampling signal at the input terminal of the power switching device is acquired to monitor the input voltage status in real time and capture any fluctuations. Then, in step 02, the sampling signal is processed and decomposed into DC and AC components. The DC component represents the stable part of the voltage, while the AC component contains ripple and noise. Then, in step 03, an inverse proportional feedforward signal is generated using the separated DC and AC components. This signal is designed to compensate for changes in the input voltage. Finally, in step 04, the inverse proportional feedforward signal is combined with the output signal at the output terminal of the power switching device. The output signal usually comes from the system's feedback loop and is used to generate a target control signal. This signal is directly used to adjust the duty cycle of the power switching device, thereby controlling the power supply output.

[0032] In this process, step 01, voltage sampling, provides real-time data on input disturbances, enabling the system to sense changes. Step 02, separation processing, utilizes signal processing principles to decompose the voltage into different frequency components, allowing for accurate identification of low-frequency fluctuations requiring compensation. Step 03, inverse proportional feedforward generation, operates on the principle that the signal duty cycle decreases when the input voltage increases and increases when it decreases, thereby offsetting the impact of disturbances. Step 04, integration, combines feedforward compensation with feedback control. The feedforward component provides a fast response, while the feedback component ensures steady-state accuracy, achieving synergistic effects and improving overall control efficiency.

[0033] Existing feedforward technology in digital switching power supplies is insufficient in compensating for low-frequency fluctuations in the input voltage, resulting in large output voltage ripple and affecting equipment performance. The precise component separation in step 02 improves the ability to identify low-frequency noise, the inverse proportional feedforward in step 03 ensures the accuracy of the compensation direction, and the direct control signal generation in step 04 avoids the delay of traditional PID adjustment, thereby improving the system response speed and stability. In terms of effect, this method can effectively suppress power frequency ripple, reduce noise in applications such as high-voltage output and weak signal detection, improve the signal-to-noise ratio, and ensure the quality of power output.

[0034] In some embodiments, step 02 above includes: The sampling signal is input to the proportional voltage divider circuit, and the output signal of the proportional voltage divider circuit is sampled by a digital control chip to obtain the first sampling signal. The first sampled signal is input into the first filter to obtain the DC component of the sampled signal; The first sampled signal is input into the first filter to obtain the second sampled signal; The AC component of the sampled signal is obtained by subtracting the DC component of the second sampled signal from the DC component of the sampled signal.

[0035] Specifically, the original sampled signal is input into a proportional voltage divider circuit for voltage scaling to accommodate the input range of subsequent digital processing circuits. A digital control chip then samples the divided signal to obtain a first sampled signal. This first sampled signal is input in parallel to two processing paths: one path inputs it to a first filter to extract the DC component representing the average voltage level, and the other path inputs it to a second filter to obtain a second sampled signal. Finally, the second sampled signal is subtracted from the previously obtained DC component to separate the AC component from the sampled signal.

[0036] Based on the concepts of signal conditioning and frequency domain separation, the proportional voltage divider circuit works by using a resistor network to linearly reduce the high-voltage signal to a safe and easily sampled level—a common and necessary step in processing high-voltage signals. The sampling principle of the digital control chip utilizes its built-in analog-to-digital converter to convert the analog voltage signal into discrete digital quantities, providing a foundation for subsequent digital filtering and other algorithmic processing. The principle of using two filters lies in leveraging their different frequency response characteristics. The first filter is designed as a low-pass filter to attenuate AC ripple, thus outputting a clean DC component, while the second filter is designed to allow AC components to pass through, or has a different cutoff frequency, ensuring that the second sampled signal retains complete AC information. The principle of subtraction is based on the fundamental mathematical relationship of signal decomposition: subtracting the DC component from the complete signal containing both DC and AC components yields the AC component as the remainder.

[0037] In some implementations, both the first filter and the second filter are moving average filters. The averaging time of the first filter is set to be greater than twice the fundamental period of the AC component of the sampled signal, and the averaging time of the second filter is set to be less than half the fundamental period.

[0038] Specifically, both the first and second filters are moving average filters. The averaging time of the first filter is set to be greater than twice the fundamental period of the AC component in the sampled signal, while the averaging time of the second filter is set to be less than half of the fundamental period.

[0039] The moving average filter achieves filtering by averaging the signal values ​​within a specified time window. The first filter, due to its longer averaging time, has a very low equivalent low-pass cutoff frequency, which can effectively smooth and filter out AC ripple, thereby accurately extracting the DC component of the signal. The second filter, due to its shorter averaging time, has a higher cutoff frequency, which can quickly respond to and retain the AC variation components in the signal. Based on the principle that the signal can be decomposed into the superposition of DC and AC, the pure AC component can be separated by subtracting the DC component from the output of the second filter.

[0040] The parameter configuration of the first and second filters enables efficient and accurate separation of DC and AC components, especially ensuring the integrity of low-frequency AC ripple information. This provides a high-precision error signal for subsequent feedforward compensation, thereby directly improving the system's real-time compensation capability for low-frequency fluctuations in the input voltage, effectively suppressing the power frequency ripple of the output voltage, and improving the performance and stability of the power supply in scenarios such as high-voltage output and weak signal detection.

[0041] In some embodiments, step 03 above includes: The AC component of the sampled signal is proportionally amplified and integrated to obtain the third sampled signal; The fourth sampled signal is obtained by superimposing the third sampled signal with the DC component of the sampled signal. The fourth sampled signal is processed by an inverse proportional function to output an inverse proportional feedforward signal.

[0042] Specifically, the process of generating the inverse proportional feedforward signal first involves proportional amplification and integration of the separated AC component. Proportional amplification precisely adjusts the amplitude of the compensation signal to meet system gain requirements, while integration corrects signal phase delay to match the dynamic response of the control loop, resulting in the third sampled signal. This third sampled signal is then superimposed with the DC component, a process that re-integrates the DC reference voltage with the processed AC ripple information, forming the fourth sampled signal. Finally, the fourth sampled signal is processed by an inverse proportional function. This function, based on a mathematical inverse relationship, causes the output signal value to decrease as the input voltage increases and vice versa, ultimately outputting the inverse proportional feedforward signal.

[0043] By optimizing the amplitude and phase characteristics of the AC component through proportional-integral processing and superimposing calculations to ensure that the compensation signal is established on the correct DC reference, the inverse proportional function directly maps the input voltage disturbance to the reverse compensation amount, thereby constructing a fast feedforward channel that can generate an accurate reverse compensation signal in real time. This greatly improves the system's ability to suppress low-frequency fluctuations in the input voltage, significantly reduces the ripple content of the output voltage, and effectively improves the stability and signal-to-noise ratio of the power supply in scenarios such as high-voltage output and weak signal detection. It overcomes the shortcomings of traditional feedforwards, such as slow response and inaccurate compensation.

[0044] Figure 3 This is a block diagram of a digital power control system provided for an embodiment of this application. Figure 3 As shown, the specific implementation process of the feedforward voltage loop is as follows: The input voltage containing the low-frequency oscillation signal passes through the circuit with the proportional voltage divider coefficient Kin, and is sampled by the digital control chip to obtain a set of sampled values. These sampled values ​​pass through two moving average filters simultaneously. The averaging time of the first moving average filter is set to be greater than twice the fundamental period. The fundamental period is the fluctuation frequency of the AC component in the DC voltage after rectification of the grid voltage. For single-phase, it is generally 100Hz or 120Hz, and for three-phase, it is generally 300Hz or 360Hz. The larger the moving average of this filter, the closer it is to the average value of the rectified voltage, i.e., the average component. This value is denoted as Vin_dc. At the same time, the sampled values ​​pass through another moving average filter, whose moving average time is at least less than 1 / 2 of the fundamental period. According to the sampling theorem, the smaller the moving average time, the closer it is to the true value. This value is denoted as Vin_R. Subtracting the above values ​​yields the AC component of the input DC voltage.

[0045] Vin_ac=Vin_R Vin_dc After obtaining the AC component, the AC signal is proportionally amplified and integrated, and then added to the original average component to obtain an average value. The signal obtained after passing through a set of inverse proportional functions is the inverse proportional feedforward signal.

[0046] In some implementations, step 04 above includes: Based on the circuit topology of the power switching devices, determine the digital voltage loop and digital current loop in the control loop; Based on the digital voltage loop and digital current loop in the control loop, determine the output signal of the control loop, so as to determine the output signal provided by the output terminal of the power switching device; The output signal of the control loop is cross-multiplied with the inverse proportional feedforward signal to generate the target control signal, which is used to control the duty cycle of the power switching device.

[0047] Specifically, such as Figure 3 As shown, the control loop consists of a digital voltage loop and a digital current loop. The voltage loop and current loop can be as follows: Figure 2 The nested mode (series) shown can also be a competing mode between the voltage loop and the current loop. The inverse proportional feedforward signal is cross-multiplied with the output of the power supply control loop to generate the target control signal, which is used to control the duty cycle of the power switching device.

[0048] In some implementations, the output signal of the control loop is determined based on the digital voltage loop and the digital current loop in the control loop, in order to determine the output signal provided at the output terminal of the power switching device, including: The digital voltage loop and digital current loop operate in either nested or competing modes. In the digital voltage loop, a current reference signal is generated based on the error between the output voltage sample value and the reference voltage; In the digital current loop, the output signal of the control loop is determined based on the error between the sampled inductor current value and the current reference signal.

[0049] Specifically, the digital voltage loop and digital current loop in the digital switching power supply control system can be configured to operate in either nested or competitive modes. In nested mode, the voltage loop acts as the outer loop to generate the current reference signal, while the current loop acts as the inner loop for fast response. In competitive mode, the two loops are allowed to operate in parallel to optimize performance.

[0050] In the digital voltage loop, the system continuously monitors the sampled value of the output voltage and compares it with a preset reference voltage to calculate the error signal. Based on this error, an accurate current reference signal is generated using algorithms such as proportional-integral (PI) and PI algorithms. This signal defines the target value of the current loop. The digital current loop receives real-time sampled values ​​of the inductor current and compares them with the current reference signal provided by the voltage loop to determine the current error. An adjustment algorithm then determines the final output signal of the control loop. This signal is directly used to drive the power switching devices to adjust their duty cycle. Utilizing the synergistic effect of dual-loop feedback, the voltage loop ensures long-term stability of the output voltage, while the current loop achieves rapid transient response. This effectively improves the system's ability to suppress load changes and input disturbances, enhancing the overall dynamic performance and reliability of the power supply.

[0051] In some implementations, the control method further includes: Based on the inverse proportional feedforward signal and the output signal provided by the output terminal of the power switching device, the generated target control signal is a pulse width modulation signal. The target duty cycle is determined by comparing the pulse width modulation signal with the carrier wave of the output signal. The duty cycle of the power switching device is controlled according to the target duty cycle.

[0052] Specifically, the final result is the PWM control voltage signal, which is compared with the carrier wave to directly obtain the duty cycle D; therefore, the input signal directly acts on the duty cycle signal; since the input signal directly acts on the duty cycle signal, the system responds relatively quickly to the input.

[0053] Computer simulations were conducted based on this scheme, demonstrating that the low-frequency fundamental component can be effectively suppressed after using the algorithm. The relevant parameters of the digital power supply are: three-phase AC input 380Vac / 50Hz; after three-phase rectification, the fundamental frequency of the DC bus voltage AC component is 300Hz; the switching voltage operating frequency is 40kHz; and the rated output of the high-voltage power supply is 3500V / 1A. The following table shows the values ​​obtained from the FFT (Fourier Transform) analysis of the output voltage using a fundamental frequency of 300Hz:

[0054] The results show that the low-frequency ripple amplitude below 1000Hz was greatly attenuated, with the amplitude of the 300Hz fundamental component attenuated by 97.7%, thus proving the effectiveness of the algorithm.

[0055] The control device provided in this application includes: The acquisition module is configured to acquire the sampling signal of the DC bus voltage connected to the input terminal of the power switching device; The first processing module is configured to process the sampled signal to separate the DC component and AC component of the sampled signal. The second processing module is configured to generate an inverse proportional feedforward signal based on the DC and AC components of the sampled signal. The third processing module is configured to generate a target control signal based on the inverse proportional feedforward signal and the output signal provided by the output terminal of the power switching device. The target control signal is used to control the duty cycle of the power switching device.

[0056] In some embodiments, the voltage feedforward-based control device further includes a pulse modulation module configured to generate a target control signal as a pulse width modulation signal based on the inverse proportional feedforward signal and the output signal provided by the output terminal of the power switching device; compare the pulse width modulation signal with the carrier of the output signal to determine the target duty cycle; and control the duty cycle of the power switching device according to the target duty cycle.

[0057] The control device provided in this application includes a memory and a processor. The memory stores a computer program, and the processor is configured to execute the control method of the above-described embodiments through the computer program. The embodiments of the control device include the voltage feedforward-based control method of the above-described embodiments, which will not be described again here.

[0058] For example, the voltage feedforward-based control method provided in this application embodiment can be executed by a computer device, which can be a terminal or a server. The terminal can be a smartphone, tablet, laptop, desktop computer, smart TV, smart speaker, wearable smart device, personal computer (PC), smart vehicle terminal, etc. The server can be an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery network (CDN), and big data and artificial intelligence platforms. However, it is not limited to these. The terminal and server can be directly or indirectly connected via wired or wireless communication, which is not limited in this application embodiment.

[0059] The switching power supply provided in this application includes the control device and power switching device provided in this application. The implementation of the switching power supply includes the voltage feedforward-based control method and control device described above, which will not be repeated here.

[0060] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0061] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0062] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0063] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer or a server) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0064] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A voltage feedforward-based control method for controlling power switching devices, characterized in that, The control method includes: Obtain the sampling signal of the DC bus voltage connected to the input terminal of the power switching device; The sampled signal is processed to separate the DC component and AC component of the sampled signal; Based on the DC and AC components of the sampled signal, an inverse proportional feedforward signal is generated; A target control signal is generated based on the inverse proportional feedforward signal and the output signal provided by the output terminal of the power switching device. The target control signal is used to control the duty cycle of the power switching device.

2. The control method based on voltage feedforward according to claim 1, characterized in that, The process of processing the sampled signal to separate the DC and AC components of the sampled signal includes: The sampling signal is input to the proportional voltage divider circuit, and the output signal of the proportional voltage divider circuit is sampled by a digital control chip to obtain the first sampling signal. The first sampled signal is input into the first filter to obtain the DC component of the sampled signal; The first sampled signal is input into the first filter to obtain the second sampled signal; The AC component of the sampled signal is obtained by subtracting the DC component of the second sampled signal from the DC component of the sampled signal.

3. The control method based on voltage feedforward according to claim 2, characterized in that, Both the first filter and the second filter are moving average filters. The averaging time of the first filter is set to be greater than twice the fundamental period of the AC component of the sampled signal, and the averaging time of the second filter is set to be less than half the fundamental period.

4. The control method based on voltage feedforward according to claim 1, characterized in that, The step of generating an inverse proportional feedforward signal based on the DC and AC components of the sampled signal includes: The AC component of the sampled signal is proportionally amplified and integrated to obtain the third sampled signal; The third sampled signal is superimposed with the DC component of the sampled signal to obtain the fourth sampled signal; The fourth sampled signal is processed by an inverse proportional function to output the inverse proportional feedforward signal.

5. The control method based on voltage feedforward according to claim 1, characterized in that, The step of generating a target control signal based on the inverse proportional feedforward signal and the output signal provided by the output terminal of the power switching device, the target control signal being used to control the duty cycle of the power switching device, includes: Based on the circuit topology of the power switching devices, determine the digital voltage loop and digital current loop in the control loop; Based on the digital voltage loop and digital current loop in the control loop, the output signal of the control loop is determined, so as to determine the output signal provided by the output terminal of the power switching device; The output signal of the control loop is cross-multiplied with the inverse proportional feedforward signal to generate a target control signal, which is used to control the duty cycle of the power switching device.

6. The control method based on voltage feedforward according to claim 5, characterized in that, The step of determining the output signal of the control loop based on the digital voltage loop and digital current loop in the control loop, in order to determine the output signal provided by the output terminal of the power switching device, includes: The digital voltage loop and the digital current loop operate in either nested or competing modes. In the digital voltage loop, a current reference signal is generated based on the error between the output voltage sample value and the reference voltage; In the digital current loop, the output signal of the control loop is determined based on the error between the sampled inductor current value and the current reference signal.

7. The control method based on voltage feedforward according to claim 1, characterized in that, The control method further includes: The target control signal generated based on the inverse proportional feedforward signal and the output signal provided by the output terminal of the power switching device is a pulse width modulation signal. The target duty cycle is determined by comparing the pulse width modulation signal with the carrier of the output signal. The duty cycle of the power switching device is controlled according to the target duty cycle.

8. A control device based on voltage feedforward, characterized in that, include: The acquisition module is configured to acquire a sampling signal of the DC bus voltage connected to the input terminal of the power switching device; The first processing module is configured to process the sampled signal to separate the DC component and AC component of the sampled signal. The second processing module is configured to generate an inverse proportional feedforward signal based on the DC and AC components of the sampled signal. The third processing module is configured to generate a target control signal based on the inverse proportional feedforward signal and the output signal provided by the output terminal of the power switching device. The target control signal is used to control the duty cycle of the power switching device.

9. The voltage feedforward-based control device according to claim 8, characterized in that, The voltage feedforward-based control device further includes: The pulse modulation module is configured to generate a pulse width modulation signal based on the inverse proportional feedforward signal and the output signal provided by the output terminal of the power switching device. The target duty cycle is determined by comparing the pulse width modulation signal with the carrier of the output signal. The duty cycle of the power switching device is controlled according to the target duty cycle.

10. A switching power supply, the switching power supply comprising: Power switching devices; The voltage-feedforward-based control device of claim 8 or 9, wherein the control device is configured to control the duty cycle of the power switching device.

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