Control method, device and circuit of current source converter

Abstract

The invention provides a control method, device and circuit of a current source type converter, and belongs to the technical field of converters. The method comprises the following steps: acquiring a direct-current reference voltage and a power grid voltage input into the current source type converter; extracting a three-phase alternating-current voltage in the power grid voltage to obtain an alternating-current reference voltage; determining a driving control signal based on the DC reference voltage, the AC reference voltage and a modulation algorithm; and controlling the current source type converter based on the driving control signal. By adopting the current source type converter, each harmonic in the power grid voltage is prevented from entering the modulation loop, and the problem of oscillation divergence of the direct current bus is solved, so that the working stability of the current source type converter and the load is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of converters, and particularly to a control method, device and circuit for a current source type converter. Background Art

[0002] A current source type converter can convert three-phase alternating current of a power grid into direct current to supply power to each load.

[0003] The control method of the current source type converter is: based on a DC reference voltage, a grid voltage and a modulation algorithm, a drive control signal is determined, and then the current source type converter is controlled based on the drive control signal.

[0004] However, in the case of a weak power grid, the harmonic power coupling generated by the interaction between the converter and the equivalent impedance of the weak power grid is serious. Each harmonic is mixed into the grid voltage and enters the modulation loop together with the three-phase alternating current, resulting in unstable drive control signals, oscillation and divergence of the DC bus voltage, affecting the normal operation of the load, and reducing the working stability of the current source type converter and the load. Summary of the Invention

[0005] Embodiments of the present disclosure provide a control method for a current source type converter, which can suppress each harmonic in the grid voltage from entering the modulation loop, solve the problem of oscillation and divergence of the DC bus, and thus improve the working stability of the current source type converter and the load. The technical solution is as follows:

[0006] In a first aspect, a control method for a current source type converter is provided. The method includes:

[0007] Obtain a DC reference voltage and a grid voltage input to the current source type converter;

[0008] Extract three-phase AC voltages in the grid voltage to obtain an AC reference voltage;

[0009] Based on the DC reference voltage, the AC reference voltage and a modulation algorithm, determine a drive control signal;

[0010] Based on the drive control signal, control the current source type converter.

[0011] In a possible implementation, the extracting three-phase AC voltages in the grid voltage to obtain an AC reference voltage includes:

[0012] Determine the frequency of the three-phase AC voltages;

[0013] Based on the frequency of the three-phase AC voltages, perform a single-frequency component extraction process on the grid voltage to obtain the AC reference voltage.

[0014] In a possible implementation, the frequency of the three-phase AC voltage is a preset fixed frequency value.

[0015] In a possible implementation, determining the frequency of the three-phase AC voltage includes:

[0016] Measuring the three-phase AC voltage based on a preset frequency measurement algorithm to obtain the frequency of the three-phase AC voltage.

[0017] In a possible implementation, extracting a single-frequency component from the grid voltage based on the frequency of the three-phase AC voltage to obtain the AC reference voltage includes:

[0018] Extracting a single-frequency component from the three-phase AC voltage in the grid voltage based on the frequency of the three-phase AC voltage and a band-pass filter to obtain the AC reference voltage.

[0019] In a possible implementation, obtaining the DC reference voltage includes:

[0020] Determining the DC reference voltage based on a preset DC bus voltage reference value, the output voltage and output current of the current source type converter, and a voltage-current double-loop control algorithm.

[0021] In a second aspect, a control device for a current source type converter is provided, and the device includes:

[0022] An acquisition module for acquiring a DC reference voltage and the grid voltage input to the current source type converter;

[0023] An extraction module for extracting the three-phase AC voltage from the grid voltage to obtain an AC reference voltage;

[0024] A determination module for determining a drive control signal based on the DC reference voltage, the AC reference voltage, and a modulation algorithm;

[0025] A control module for controlling the current source type converter based on the drive control signal.

[0026] In a possible implementation, the extraction module is used to:

[0027] Determine the frequency of the three-phase AC voltage;

[0028] Extract a single-frequency component from the grid voltage based on the frequency of the three-phase AC voltage to obtain the AC reference voltage.

[0029] In a possible implementation, the frequency of the three-phase AC voltage is a preset fixed frequency value.

[0030] In a possible implementation, the extraction module is configured to:

[0031] Measure the three-phase AC voltage based on a preset frequency measurement algorithm to obtain the frequency of the three-phase AC voltage.

[0032] In a possible implementation, the extraction module is configured to:

[0033] Extract the single-frequency component of the three-phase AC voltage in the grid voltage based on the frequency of the three-phase AC voltage and a band-pass filter to obtain the AC reference voltage.

[0034] In a possible implementation, the acquisition module is configured to:

[0035] Determine the DC reference voltage based on a preset DC bus voltage reference value, the output voltage and output current of the current source type converter, and a voltage-current double-loop control algorithm.

[0036] In a third aspect, a control circuit for a current source type converter is provided. The control circuit includes a current source type converter and a controller;

[0037] The controller is configured to:

[0038] Obtain the DC reference voltage and the grid voltage input to the current source type converter;

[0039] Extract the three-phase AC voltage in the grid voltage to obtain the AC reference voltage;

[0040] Determine a drive control signal based on the DC reference voltage, the AC reference voltage, and a modulation algorithm;

[0041] Control the current source type converter based on the drive control signal.

[0042] In a possible implementation, the controller is configured to:

[0043] Determine the frequency of the three-phase AC voltage;

[0044] Extract the single-frequency component of the grid voltage based on the frequency of the three-phase AC voltage to obtain the AC reference voltage.

[0045] In a possible implementation, the frequency of the three-phase AC voltage is a preset fixed value.

[0046] In a possible implementation, the controller is configured to:

[0047] Measure the three-phase AC voltage based on a preset frequency measurement algorithm to obtain the frequency of the three-phase AC voltage.

[0048] In a possible implementation, the controller is configured to:

[0049] Extract a single frequency component from the three-phase AC voltage in the grid voltage based on the frequency of the three-phase AC voltage and a band-pass filter to obtain the AC reference voltage.

[0050] In a possible implementation, the controller is configured to:

[0051] Determine the DC reference voltage based on a preset DC bus voltage reference value, the output voltage and output current of the current source type converter, and a voltage-current double-loop control algorithm.

[0052] In a fourth aspect, a computer device is provided. The computer device includes a processor and a memory. At least one instruction is stored in the memory, and the instruction is loaded and executed by the processor to implement the operations performed by the control method of the current source type converter.

[0053] In a fifth aspect, a computer-readable storage medium is provided. At least one instruction is stored in the storage medium, and the instruction is loaded and executed by the processor to implement the operations performed by the control method of the current source type converter.

[0054] In a sixth aspect, a computer program product is provided. The computer program product includes at least one instruction, and the at least one instruction is loaded and executed by the processor to implement the operations performed by the control method of the current source type converter.

[0055] The beneficial effects brought by the technical solutions provided in the embodiments of the present disclosure are as follows: In the solutions mentioned in the embodiments of the present disclosure, since the AC reference voltage is obtained by extracting the three-phase alternating current in the grid voltage, various harmonics in the grid voltage are suppressed from entering the modulation loop, the problem of DC bus oscillation divergence is solved, and thus the working stability of the current source type converter and the load is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] To more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0057] Figure 1 It is a topological schematic diagram of a current source type converter provided by an embodiment of the present disclosure;

[0058] Figure 2 is a flowchart of a control method for a current source type converter provided by an embodiment of the present disclosure;

[0059] Figure 3 is a flowchart of a control method for a current source type converter provided by an embodiment of the present disclosure;

[0060] Figure 4 is a schematic diagram of a method for extracting a single frequency component from a grid voltage provided by an embodiment of the present disclosure;

[0061] Figure 5 is a schematic structural diagram of a control device for a current source type converter provided by an embodiment of the present disclosure;

[0062] Figure 6 is a structural block diagram of a terminal provided by an embodiment of the present disclosure;

[0063] Figure 7 is a structural block diagram of a server provided by an embodiment of the present disclosure. Specific embodiments

[0064] To make the objectives, technical solutions, and advantages of the present disclosure clearer, the following will further describe the embodiments of the present disclosure in detail with reference to the accompanying drawings.

[0065] The embodiments of the present disclosure provide a control method for a current source type converter, and this method can be implemented by a computer device. The computer device can be a terminal, a server, etc. The terminal can be a desktop computer, a notebook computer, a tablet computer, a mobile phone, etc.

[0066] The computer device can include a processor, a memory, a communication component, etc.

[0067] The processor can be a central processing unit (CPU), and the processor can be used to read instructions and process data. The memory can be various volatile memories or non-volatile memories, such as a solid state disk (SSD), a dynamic random access memory (DRAM), etc. The communication component can be a wired network connector, a wireless fidelity (WiFi) module, a Bluetooth module, a cellular network communication module, etc. The communication component can be used to transmit data with other devices.

[0068] See Figure 1 , Figure 1 is a topological schematic diagram of a current source type converter, where, v gabcIs the current voltage of the three phases in three-phase alternating current, V dc Is the output voltage of the current source type converter, i dc Is the output current of the current source type converter, which can convert three-phase alternating current into direct current to form a DC bus.

[0069] Figure 2 Is a flowchart of a control method for a current source type converter provided by an embodiment of the present disclosure. Refer to Figure 2 , This embodiment includes:

[0070] 201. Obtain the DC reference voltage and the grid voltage input to the current source type converter.

[0071] The DC reference voltage is a voltage value that needs to be adjusted by the current source type converter, which is calculated based on a control algorithm, and can also be called the DC voltage adjustment value. In a possible implementation, the method for obtaining the DC reference voltage can be:

[0072] Based on the preset DC bus voltage reference value, the output voltage and output current of the current source type converter, and the voltage-current double-loop control algorithm, determine the DC reference voltage.

[0073] In implementation, the preset DC bus voltage reference value is set according to the load demand, or is already set when the load leaves the factory, that is, the voltage value that can supply the load to work stably. Refer to Figure 3 , Input the preset DC bus voltage reference value, the output voltage and output current of the current source type converter into the voltage-current double-loop control algorithm to obtain the output DC reference voltage.

[0074] Furthermore, the voltage-current double-loop control algorithm includes a voltage control algorithm and a current control algorithm. Input the preset DC bus voltage reference value and the output voltage of the current source type converter into the voltage control algorithm to obtain the output current reference value. Input the current reference value and the output current of the current source type converter into the current control algorithm to obtain the output DC reference voltage.

[0075] Of course, in the embodiment of the present disclosure, the method for the DC reference voltage can be determined based on the voltage-current double-loop control algorithm, and the above voltage-current double-loop control algorithm can also be replaced by other algorithms, such as a voltage single-loop algorithm, a proportional-integral control algorithm, a non-linear control method in which the loop output is positively correlated with the voltage error, and so on.

[0076] The above is the method for obtaining the DC reference voltage, and for the grid voltage input to the current source type converter, it can be directly obtained.

[0077] 202. Extract the three-phase AC voltages in the grid voltage to obtain the AC reference voltage.

[0078] In implementation, since the grid voltage not only has three-phase AC voltage but also carries various harmonics generated, therefore, in order to suppress the entry of various harmonics into the modulation algorithm along with the three-phase AC voltage, the three-phase AC voltage in the grid voltage can be extracted to obtain an AC reference voltage with harmonics removed.

[0079] In a possible implementation manner, referring to Figure 3 , the method for obtaining the AC reference voltage can be: determining the frequency of the three-phase AC voltage; based on the frequency of the three-phase AC voltage, performing a single-frequency component extraction process on the grid voltage to obtain the AC reference voltage.

[0080] In implementation, since the frequency of the three-phase AC voltage is quite different from the frequency of the harmonics, therefore, the frequency of the three-phase AC voltage can be determined first, and then the method of single-frequency component extraction process can be used to extract the voltage of this frequency from the grid voltage. In this way, the three-phase AC voltage with harmonics removed is obtained, which is the AC reference voltage.

[0081] In a possible implementation manner, the frequency of the three-phase AC voltage can be a preset fixed value. Usually, when the power grid is relatively stable, the frequency of the three-phase AC voltage will stabilize near a fixed value. Therefore, the frequency of the three-phase AC voltage can be set to this fixed value. For example, the frequency of the three-phase AC voltage can be set to 50 Hz according to the actual situation.

[0082] In another possible implementation manner, the frequency of the three-phase AC voltage can also be measured in real time. The method can be: based on a preset frequency measurement algorithm, measuring the three-phase AC voltage to obtain the frequency of the three-phase AC voltage.

[0083] In this way, the obtained frequency of the three-phase AC voltage is more accurate. And when the power grid is relatively unstable, the frequency of the three-phase AC voltage will also change. Therefore, the frequency of the three-phase AC voltage obtained based on the measurement will be closer to the actual situation of the three-phase AC voltage, and thus the accuracy of the extracted three-phase AC voltage can be improved.

[0084] There can be various preset frequency measurement algorithms for measuring the frequency of the three-phase AC voltage. For example, it can be a phase-locked loop, a frequency-locked loop, etc. Or, other methods for measuring frequency can also be used. The embodiments of the present disclosure do not limit this.

[0085] In a possible implementation manner, after obtaining the frequency of the three-phase AC voltage, referring to Figure 4 , the method for performing a single-frequency component extraction process on the grid voltage can be: transforming the three-phase AC voltage Vgabc in the abc coordinate system to the αβ coordinate system to obtain two-phase voltage components, and then based on these two-phase voltage components and the frequency of the three-phase AC voltage, obtaining the AC reference voltage.

[0086] 1. Convert the three-phase voltage Vgabc in the abc coordinate system to the αβ coordinate system to obtain the voltage calculation vector Vc and the actual voltage vector Vr;

[0087] 2. Rotate the voltage calculation vector Vc|t=nΔT by an angle of ωgΔT at the moment t=nΔT to obtain the predicted voltage vector Vcpre|t=(n + 1)ΔT at the moment t=(n + 1)ΔT, where ωg is the frequency of the three-phase alternating current obtained in the above process;

[0088] 3. Calculate the α-axis component of the predicted voltage vector Vcpre|t=(n + 1)ΔT and the α-axis component of the actual voltage vector Vr|t=(n + 1)ΔT, and then calculate the error Verr for the two calculated α-axis components;

[0089] 4. The α-axis component of the voltage calculation vector Vcpre|t=(n + 1)ΔT at the moment t=(n + 1)ΔT is Vcα|t=(n + 1)ΔT = Vcpreα|t=(n + 1)ΔT+Verr*Ki, and its β-axis component is Vcβ|t=(n + 1)ΔT = Vcpreβ|t=(n + 1)ΔT; where Ki is the integral coefficient;

[0090] 5. Based on the α-axis component and the β-axis component of the voltage calculation vector Vcpre|t=(n + 1)ΔT, calculate the value of the voltage calculation vector Vc|t=(n + 1)ΔT, and then convert the obtained value of the voltage calculation vector Vc|t=(n + 1)ΔT to the abc coordinate system to obtain its fundamental frequency voltage component Vg1abc.

[0091] In another possible implementation, the method for extracting a single frequency component from the grid voltage can also be: based on the frequency of the three-phase alternating voltage and a band-pass filter, extract a single frequency component from the three-phase alternating voltage in the grid voltage to obtain an alternating current reference voltage.

[0092] In implementation, set the parameters of the band-pass filter based on the frequency of the three-phase alternating voltage, and input the grid voltage into the band-pass filter to obtain the output alternating current reference voltage.

[0093] Or, the method for extracting a single frequency component from the grid voltage can also be any other reasonable method, which is not limited in the embodiments of the present disclosure.

[0094] 203. Determine the drive control signal based on the DC reference voltage, the AC reference voltage, and the modulation algorithm.

[0095] In implementation, refer to Figure 3, the obtained DC reference voltage and AC reference voltage can be input into a modulation algorithm for modulation to obtain an output drive control signal.

[0096] 204. Control the current source converter based on the drive control signal.

[0097] In implementation, based on the drive control signal, multiple controllable semiconductor switch devices in the current source converter can be controlled. By controlling the turning on or off of the multiple controllable semiconductor switch devices, the output voltage of the current source converter can be made closer to a preset DC bus voltage reference value, thereby effectively powering the load.

[0098] All the above optional technical solutions can be combined arbitrarily to form alternative embodiments of the present disclosure, which will not be elaborated here one by one.

[0099] In the embodiments of the present disclosure, since the AC reference voltage is obtained by extracting the three-phase alternating current in the grid voltage, the harmonics in the grid voltage are suppressed from entering the modulation loop, solving the problem of DC bus oscillation divergence, thereby improving the operating stability of the current source converter and the load.

[0100] The embodiments of the present disclosure provide a control device for a current source converter. The device can be the computer device in the above embodiments, such as Figure 5 As shown, the device includes:

[0101] An acquisition module 510, configured to acquire a DC reference voltage and the grid voltage input to the current source converter;

[0102] An extraction module 520, configured to extract the three-phase AC voltage in the grid voltage to obtain an AC reference voltage;

[0103] A determination module 530, configured to determine a drive control signal based on the DC reference voltage, the AC reference voltage, and a modulation algorithm;

[0104] A control module 540, configured to control the current source converter based on the drive control signal.

[0105] In a possible implementation manner, the extraction module 520 is configured to:

[0106] Determine the frequency of the three-phase AC voltage;

[0107] Based on the frequency of the three-phase AC voltage, perform a single-frequency component extraction process on the grid voltage to obtain the AC reference voltage.

[0108] In a possible implementation manner, the frequency of the three-phase AC voltage is a preset fixed value.

[0109] In a possible implementation, the extraction module 520 is configured to:

[0110] Measure the three-phase AC voltage based on a preset frequency measurement algorithm to obtain the frequency of the three-phase AC voltage.

[0111] In a possible implementation, the extraction module 520 is configured to:

[0112] Extract a single frequency component from the three-phase AC voltage in the grid voltage based on the frequency of the three-phase AC voltage and a band-pass filter to obtain the AC reference voltage.

[0113] In a possible implementation, the acquisition module 510 is configured to:

[0114] Determine the DC reference voltage based on a preset DC bus voltage reference value, the output voltage and output current of the current source type converter, and a voltage-current double-loop control algorithm.

[0115] The embodiments of the present disclosure further provide a control circuit for a current source type converter. The control circuit includes a current source type converter and a controller;

[0116] The controller is configured to:

[0117] Acquire a DC reference voltage and the grid voltage input to the current source type converter;

[0118] Extract the three-phase AC voltage from the grid voltage to obtain an AC reference voltage;

[0119] Determine a drive control signal based on the DC reference voltage, the AC reference voltage, and a modulation algorithm;

[0120] Control the current source type converter based on the drive control signal.

[0121] In a possible implementation, the controller is configured to:

[0122] Determine the frequency of the three-phase AC voltage;

[0123] Extract a single frequency component from the grid voltage based on the frequency of the three-phase AC voltage to obtain the AC reference voltage.

[0124] In a possible implementation, the frequency of the three-phase AC voltage is a preset fixed value.

[0125] In a possible implementation, the controller is configured to:

[0126] Measure the three-phase AC voltage based on a preset frequency measurement algorithm to obtain the frequency of the three-phase AC voltage.

[0127] In a possible implementation, the controller is configured to:

[0128] Extract a single-frequency component from the three-phase AC voltage in the grid voltage based on the frequency of the three-phase AC voltage and a band-pass filter to obtain the AC reference voltage.

[0129] In a possible implementation, the controller is configured to:

[0130] Determine the DC reference voltage based on a preset DC bus voltage reference value, the output voltage and output current of the current source type converter, and a voltage-current double-loop control algorithm.

[0131] It should be noted that: when the control device of the current source type converter provided in the above embodiment controls the current source type converter, only the division of the above functional modules is used for illustration. In actual applications, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the control device of the current source type converter provided in the above embodiment and the embodiment of the control method of the current source type converter belong to the same concept, and the specific implementation process is detailed in the method embodiment, which will not be elaborated here.

[0132] Figure 6 The block diagram of a terminal 600 provided by an exemplary embodiment of the present disclosure is shown. The terminal may be the computer device in the above embodiment. The terminal 600 may be: a smart phone, a tablet computer, an MP3 player (Moving Picture Experts Group Audio Layer III), an MP4 (Moving Picture Experts Group Audio Layer IV) player, a laptop computer or a desktop computer. The terminal 600 may also be referred to by other names such as user equipment, portable terminal, laptop terminal, desktop terminal, etc.

[0133] Generally, the terminal 600 includes: a processor 601 and a memory 602.

[0134] The processor 601 may include one or more processing cores, such as a quad-core processor, an octa-core processor, etc. The processor 601 may be implemented in at least one hardware form of DSP (digital signal processing), FPGA (field-programmable gate array), or PLA (programmable logic array). The processor 601 may also include a main processor and a coprocessor. The main processor is a processor used to process data in the wake state, also known as the CPU (central processing unit); the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor 601 may be integrated with a GPU (graphics processing unit), and the GPU is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 601 may further include an AI (artificial intelligence) processor, and the AI processor is used to process computational operations related to machine learning.

[0135] The memory 602 may include one or more computer-readable storage media, and the computer-readable storage media may be non-transitory. The memory 602 may further include high-speed random access memory and non-volatile memory, such as one or more disk storage devices and flash storage devices. In some embodiments, the non-transitory computer-readable storage media in the memory 602 is used to store at least one instruction, and the at least one instruction is used to be executed by the processor 601 to implement the control method of the current source type converter provided in the method embodiments of the present disclosure.

[0136] In some embodiments, the terminal 600 may further optionally include: a peripheral device interface 603 and at least one peripheral device. The processor 601, the memory 602, and the peripheral device interface 603 may be connected through a bus or signal lines. Each peripheral device may be connected to the peripheral device interface 603 through a bus, signal lines, or a circuit board. Specifically, the peripheral devices include at least one of a radio frequency circuit 604, a display screen 605, a camera 606, an audio circuit 607, a positioning component 608, and a power supply 609.

[0137] The peripheral device interface 603 can be used to connect at least one I / O (input / output) related peripheral device to the processor 601 and the memory 602. In some embodiments, the processor 601, the memory 602, and the peripheral device interface 603 are integrated on the same chip or circuit board; in some other embodiments, any one or two of the processor 601, the memory 602, and the peripheral device interface 603 can be implemented on a separate chip or circuit board, and this embodiment does not limit this.

[0138] The radio frequency circuit 604 is used to receive and transmit RF (radio frequency) signals, also known as electromagnetic signals. The radio frequency circuit 604 communicates with a communication network and other communication devices through electromagnetic signals. The radio frequency circuit 604 converts an electrical signal into an electromagnetic signal for transmission, or converts the received electromagnetic signal into an electrical signal. Optionally, the radio frequency circuit 604 includes: an antenna system, an RF transceiver, one or more amplifiers, a tuner, an oscillator, a digital signal processor, a codec chipset, a subscriber identity module card, and so on. The radio frequency circuit 604 can communicate with other terminals through at least one wireless communication protocol. The wireless communication protocol includes but is not limited to: metropolitan area network, each generation of mobile communication network (2G, 3G, 4G, and 5G), wireless local area network, and / or WiFi (wireless fidelity) network. In some embodiments, the radio frequency circuit 604 can also include a circuit related to NFC (near field communication), and the present disclosure does not limit this.

[0139] The display screen 605 is used to display the UI (user interface). The UI may include graphics, text, icons, videos, and any combination thereof. When the display screen 605 is a touch display screen, the display screen 605 also has the ability to collect touch signals on or above the surface of the display screen 605. The touch signals can be input to the processor 601 as control signals for processing. At this time, the display screen 605 can also be used to provide virtual buttons and / or virtual keyboards, also known as soft buttons and / or soft keyboards. In some embodiments, there may be one display screen 605, which is provided on the front panel of the terminal 600; in other embodiments, there may be at least two display screens 605, which are respectively provided on different surfaces of the terminal 600 or in a foldable design; in still other embodiments, the display screen 605 may be a flexible display screen, which is provided on the curved surface or the folding surface of the terminal 600. Even further, the display screen 605 can also be set to an irregular non-rectangular shape, that is, a special-shaped screen. The display screen 605 can be prepared using materials such as LCD (liquid crystal display) and OLED (organic light-emitting diode).

[0140] The camera module 606 is used to capture images or videos. Optionally, the camera module 606 includes a front camera and a rear camera. Generally, the front camera is provided on the front panel of the terminal, and the rear camera is provided on the back of the terminal. In some embodiments, there are at least two rear cameras, which are any one of a main camera, a depth-of-field camera, a wide-angle camera, and a telephoto camera, to achieve functions such as the combination of the main camera and the depth-of-field camera to achieve the background blur function, the combination of the main camera and the wide-angle camera to achieve panoramic shooting and VR (virtual reality) shooting functions, or other combined shooting functions. In some embodiments, the camera module 606 may also include a flash. The flash can be a single-color temperature flash or a two-color temperature flash. A two-color temperature flash refers to the combination of a warm light flash and a cold light flash, which can be used for light compensation under different color temperatures.

[0141] The audio circuit 607 may include a microphone and a speaker. The microphone is used to collect sound waves of the user and the environment, and convert the sound waves into electrical signals for input to the processor 601 for processing, or input to the radio frequency circuit 604 to achieve voice communication. For the purpose of stereo collection or noise reduction, there may be multiple microphones, which are respectively arranged at different parts of the terminal 600. The microphone may also be an array microphone or an omnidirectional collection microphone. The speaker is used to convert the electrical signal from the processor 601 or the radio frequency circuit 604 into sound waves. The speaker may be a traditional thin film speaker or a piezoelectric ceramic speaker. When the speaker is a piezoelectric ceramic speaker, it can not only convert the electrical signal into sound waves audible to humans, but also convert the electrical signal into sound waves inaudible to humans for uses such as ranging. In some embodiments, the audio circuit 607 may also include a headphone jack.

[0142] The positioning component 608 is used to locate the current geographical location of the terminal 600 to achieve navigation or LBS (location based service). The positioning component 608 may be a positioning component based on GPS (global positioning system), Beidou system, GLONASS system or Galileo system.

[0143] The power supply 609 is used to supply power to each component in the terminal 600. The power supply 609 may be alternating current, direct current, a disposable battery or a rechargeable battery. When the power supply 609 includes a rechargeable battery, the rechargeable battery may support wired charging or wireless charging. The rechargeable battery may also be used to support fast charging technology.

[0144] In some embodiments, the terminal 600 further includes one or more sensors 610. The one or more sensors 610 include but are not limited to: an acceleration sensor 611, a gyroscope sensor 612, a pressure sensor 613, a fingerprint sensor 614, an optical sensor 615 and a proximity sensor 616.

[0145] The acceleration sensor 611 can detect the magnitude of acceleration on the three coordinate axes of the coordinate system established with the terminal 600. For example, the acceleration sensor 611 can be used to detect the components of the gravitational acceleration on the three coordinate axes. The processor 601 can control the display screen 605 to display the user interface in a landscape view or a portrait view according to the gravitational acceleration signal collected by the acceleration sensor 611. The acceleration sensor 611 can also be used for collecting game or user's motion data.

[0146] The gyroscope sensor 612 can detect the body orientation and rotation angle of the terminal 600. The gyroscope sensor 612 can cooperate with the acceleration sensor 611 to collect the 3D actions of the user on the terminal 600. Based on the data collected by the gyroscope sensor 612, the processor 601 can implement the following functions: motion sensing (such as changing the UI according to the user's tilting operation), image stabilization during shooting, game control, and inertial navigation.

[0147] The pressure sensor 613 can be disposed on the side frame of the terminal 600 and / or the lower layer of the display screen 605. When the pressure sensor 613 is disposed on the side frame of the terminal 600, it can detect the holding signal of the user on the terminal 600, and the processor 601 can perform left / right hand recognition or shortcut operations based on the holding signal collected by the pressure sensor 613. When the pressure sensor 613 is disposed on the lower layer of the display screen 605, the processor 601 can control the operable controls on the UI interface according to the pressure operation of the user on the display screen 605. The operable controls include at least one of button controls, scroll bar controls, icon controls, and menu controls.

[0148] The fingerprint sensor 614 is used to collect the fingerprint of the user. The processor 601 can identify the user's identity based on the fingerprint collected by the fingerprint sensor 614, or the fingerprint sensor 614 can identify the user's identity based on the collected fingerprint. When the identified user identity is a trusted identity, the processor 601 authorizes the user to perform relevant sensitive operations, and the sensitive operations include unlocking the screen, viewing encrypted information, downloading software, making payments, and changing settings, etc. The fingerprint sensor 614 can be disposed on the front, back, or side of the terminal 600. When there are physical buttons or manufacturer logos on the terminal 600, the fingerprint sensor 614 can be integrated with the physical buttons or manufacturer logos.

[0149] The optical sensor 615 is used to collect the ambient light intensity. In one embodiment, the processor 601 can control the display brightness of the display screen 605 according to the ambient light intensity collected by the optical sensor 615. Specifically, when the ambient light intensity is high, the display brightness of the display screen 605 is increased; when the ambient light intensity is low, the display brightness of the display screen 605 is decreased. In another embodiment, the processor 601 can also dynamically adjust the shooting parameters of the camera module 606 according to the ambient light intensity collected by the optical sensor 615.

[0150] A proximity sensor 616, also known as a distance sensor, is typically disposed on the front panel of the terminal 600. The proximity sensor 616 is used to collect the distance between the user and the front of the terminal 600. In one embodiment, when the proximity sensor 616 detects that the distance between the user and the front of the terminal 600 is gradually decreasing, the processor 601 controls the display screen 605 to switch from the lit state to the off state; when the proximity sensor 616 detects that the distance between the user and the front of the terminal 600 is gradually increasing, the processor 601 controls the display screen 605 to switch from the off state to the lit state.

[0151] Those skilled in the art can understand that Figure 6 the structure shown in does not constitute a limitation on the terminal 600, and may include more or fewer components than shown in the figure, or combine some components, or adopt a different component layout.

[0152] Figure 7 is a schematic structural diagram of a server provided by an embodiment of the present disclosure. The server 700 may vary greatly due to different configurations or performances, and may include one or more processors (central processing units, CPUs) 701 and one or more memories 702. Among them, at least one instruction is stored in the memory 702, and the at least one instruction is loaded and executed by the processor 701 to implement the methods provided by the above-mentioned various method embodiments. Of course, the server may also have components such as wired or wireless network interfaces, keyboards, and input / output interfaces for input / output. The server may also include other components for implementing device functions, which will not be elaborated here.

[0153] In an exemplary embodiment, a computer-readable storage medium is also provided. For example, a memory including instructions, and the above instructions can be executed by a processor in the terminal to complete the control method of the current-source type converter in the above embodiment. The computer-readable storage medium may be non-transitory. For example, the computer-readable storage medium may be a ROM (read-only memory), a RAM (random access memory), a CD-ROM, a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0154] Those of ordinary skill in the art can understand that all or part of the steps of implementing the above embodiments can be completed by hardware, or can be completed by a program instructing relevant hardware. The program can be stored in a computer-readable storage medium, and the above-mentioned storage medium can be a read-only memory, a magnetic disk, or an optical disc, etc.

[0155] It should be noted that the information involved in this disclosure (including but not limited to user device information, user personal information, etc.), data (including but not limited to data for analysis, stored data, displayed data, etc.), and signals (including but not limited to signals transmitted between user terminals and other devices, etc.) are all authorized by users or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with the relevant laws, regulations, and standards of relevant countries and regions. For example, the "grid voltage", "drive control signal", etc. involved in this disclosure are all obtained under full authorization.

[0156] The above are only optional embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present disclosure shall be included within the protection scope of the present disclosure.

Claims

1. A control method for a current source type converter, characterized in that, The method includes: Obtaining a DC reference voltage and a grid voltage input to the current source type converter; Extracting three-phase AC voltages from the grid voltage to obtain an AC reference voltage; Determining a drive control signal based on the DC reference voltage, the AC reference voltage, and a modulation algorithm; Controlling the current source type converter based on the drive control signal.

2. The method according to claim 1, wherein The extracting three-phase AC voltages from the grid voltage to obtain an AC reference voltage includes: Determining the frequency of the three-phase AC voltages; Performing a single-frequency component extraction process on the grid voltage based on the frequency of the three-phase AC voltages to obtain the AC reference voltage.

3. The method according to claim 2, wherein The frequency of the three-phase AC voltages is a preset fixed value.

4. The method according to claim 2, wherein The determining the frequency of the three-phase AC voltages includes: Measuring the three-phase AC voltages based on a preset frequency measurement algorithm to obtain the frequency of the three-phase AC voltages.

5. The method according to claim 2, characterized in that, The performing a single-frequency component extraction process on the grid voltage based on the frequency of the three-phase AC voltages to obtain the AC reference voltage includes: Performing a single-frequency component extraction process on the three-phase AC voltages in the grid voltage based on the frequency of the three-phase AC voltages and a band-pass filter to obtain the AC reference voltage.

6. The method according to claim 1, characterized in that The obtaining a DC reference voltage includes: Determining the DC reference voltage based on a preset bus DC voltage reference value, the output voltage and output current of the current source type converter, and a voltage-current double-loop control algorithm.

7. A control device for a current source type converter, characterized in that, The device includes: An obtaining module, configured to obtain a DC reference voltage and a grid voltage input to the current source type converter; An extracting module, configured to extract three-phase AC voltages from the grid voltage to obtain an AC reference voltage; A determining module, configured to determine a drive control signal based on the DC reference voltage, the AC reference voltage, and a modulation algorithm; A control module, configured to control the current source type converter based on the drive control signal.

8. A control circuit for a current source type converter, characterized in that, The control circuit includes a current source type converter and a controller; The controller is configured to: Obtain a DC reference voltage and a grid voltage input to the current source type converter; Extract three-phase AC voltages from the grid voltage to obtain an AC reference voltage; Determine a drive control signal based on the DC reference voltage, the AC reference voltage, and a modulation algorithm; Control the current source type converter based on the drive control signal.

9. A computer device, characterized in that, The computer device includes a processor and a memory, and at least one instruction is stored in the memory, and the at least one instruction is loaded and executed by the processor to implement the operations performed by the control method of the current source type converter according to any one of claims 1 to 6.

10. A computer-readable storage medium, characterized in that, At least one instruction is stored in the storage medium, and the at least one instruction is loaded and executed by a processor to implement the operations performed by the control method of the current source type converter according to any one of claims 1 to 6.

11. A computer program product, characterized in that, The computer program product includes at least one instruction, and the at least one instruction is loaded and executed by a processor to implement the operations performed by the control method of the current source type converter according to any one of claims 1 to 6.

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