Current source converter control method, device, circuit, equipment and medium

Abstract

The invention provides a control method, device, circuit and equipment of a current source type converter and a medium, and belongs to the technical field of converters. The method comprises the following steps: detecting a direct-current voltage output by a current source type converter; when the direct-current voltage is greater than the direct-current upper limit threshold value, a plurality of controllable switching devices in the current source type converter are controlled to be switched off, so that a charging loop of a direct-current bus capacitor in the current source type converter is switched off; and when the direct current voltage is smaller than the first direct current lower limit threshold value, determining a driving control signal, and controlling a plurality of controllable switching devices in the current source type converter based on the driving control signal. According to the invention, the plurality of controllable switching devices are controlled to be switched off and stop charging the bus capacitor, and in the process, the bus capacitor charges the load all the time so as to reduce the DC voltage, thereby reducing the possibility of DC overvoltage protection events and load safety threat events, and improving the stability and safety of load operation.

Description

Technical Field

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

[0002] Three-phase alternating current can be subjected to AC-DC conversion through a current source type converter to output a DC voltage for supplying power to some loads.

[0003] Generally, a current source type converter controls the conduction or shutdown of multiple controllable switching devices therein based on the input three-phase alternating current and the DC voltage required by the load, so as to charge the bus capacitor in the current source type converter. Then, the bus capacitor discharges to output a DC voltage.

[0004] However, in the actual working process, when the current source type converter needs to supply power to a light load, it may cause the power transmitted on the DC side to be greater than the power required by the load, resulting in continuous accumulation of energy in the bus capacitor and continuous increase of the DC voltage, triggering DC overvoltage protection or threatening the safety of the load, thus affecting normal operation. Summary of the Invention

[0005] An embodiment of the present disclosure provides a control method for a current source type converter, which can reduce the possibility of occurrence of DC overvoltage protection events and events threatening the safety of the load, and improve the stability and safety of load operation. 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] Detect the DC voltage output by the current source type converter;

[0008] When the DC voltage is greater than the DC upper limit threshold, control the multiple controllable switching devices in the current source type converter to disconnect, so as to disconnect the charging circuit of the DC bus capacitor in the current source type converter;

[0009] When the DC voltage is less than the first DC lower limit threshold, determine a drive control signal, and based on the drive control signal, control the multiple controllable switching devices in the current source type converter.

[0010] In a possible implementation manner, the DC upper limit threshold is the sum of the DC voltage reference value and the upper fluctuation value, where the DC voltage reference value is the DC voltage expected to be input by the target load driven by the current source type converter, and the upper fluctuation value is a positive value.

[0011] In a possible implementation, the DC lower threshold is the difference between the DC voltage reference value and the lower fluctuation value, where the DC voltage reference value is the DC voltage that the target load driven by the current source type converter expects to input, and the lower fluctuation value is a positive value.

[0012] In a possible implementation, the determining the drive control signal includes:

[0013] Based on the DC voltage reference value, the DC voltage, and the first specified control algorithm, determine the voltage regulation value, where the DC voltage reference value is the DC voltage that the target load driven by the current source type converter expects to input;

[0014] Based on the voltage regulation value, determine the drive control signal.

[0015] In a possible implementation, the method further includes:

[0016] When the duration reaches a preset duration after controlling a plurality of controllable switch devices in the current source type converter based on the drive control signal, if the DC voltage is less than the second DC lower threshold, then switch the first specified control algorithm to the second specified control algorithm, where the second DC lower threshold is greater than the first DC lower threshold and less than the DC upper threshold.

[0017] In a possible implementation, the first specified control algorithm is a voltage-current double-loop control algorithm, and the second specified control algorithm is a voltage single-loop control algorithm, a proportional control algorithm, a proportional-integral control algorithm, or a non-linear control algorithm.

[0018] In a possible implementation, the method further includes:

[0019] When switching the first specified control algorithm to the second specified control algorithm, use the voltage regulation value finally output by the first specified control algorithm as the initial value of the voltage regulation value of the second specified control algorithm.

[0020] In a possible implementation, the method further includes:

[0021] After switching the first specified control algorithm to the second specified control algorithm, when the DC voltage rises to the second DC lower threshold, switch the second specified control algorithm to the first specified control algorithm.

[0022] In a possible implementation, the method further includes:

[0023] When switching the second specified control algorithm to the first specified control algorithm, use the voltage regulation value finally output by the second specified control algorithm as the initial value of the voltage regulation value of the first specified control algorithm.

[0024] In a second aspect, a control device for a current source type converter is provided. The device includes:

[0025] A detection module for detecting the DC voltage output by the current source type converter;

[0026] A first control module for controlling a plurality of controllable switch devices in the current source type converter to disconnect when the DC voltage is greater than the DC upper threshold value, so as to disconnect the charging circuit of the DC bus capacitor in the current source type converter;

[0027] A second control module for determining a drive control signal when the DC voltage is less than the first DC lower threshold value, and controlling a plurality of controllable switch devices in the current source type converter based on the drive control signal.

[0028] In a possible implementation, the DC upper threshold value is the sum of the DC voltage reference value and the upper fluctuation value, where the DC voltage reference value is the DC voltage expected to be input by the target load driven by the current source type converter, and the upper fluctuation value is a positive value.

[0029] In a possible implementation, the DC lower threshold value is the difference between the DC voltage reference value and the lower fluctuation value, where the DC voltage reference value is the DC voltage expected to be input by the target load driven by the current source type converter, and the lower fluctuation value is a positive value.

[0030] In a possible implementation, the second control module is used for:

[0031] Determine a voltage regulation value based on the DC voltage reference value, the DC voltage, and the first specified control algorithm, where the DC voltage reference value is the DC voltage expected to be input by the target load driven by the current source type converter;

[0032] Determine a drive control signal based on the voltage regulation value.

[0033] In a possible implementation, the second control module is further used for:

[0034] When the duration reaches a preset duration after controlling a plurality of controllable switching devices in the current source type converter based on the drive control signal, if the DC voltage is less than a second DC lower limit threshold, the first specified control algorithm is switched to a second specified control algorithm, where the second DC lower limit threshold is greater than the first DC lower limit threshold and less than the DC upper limit threshold.

[0035] In a possible implementation manner, the first specified control algorithm is a voltage-current double-loop control algorithm, and the second specified control algorithm is a voltage single-loop control algorithm, a proportional control algorithm, a proportional-integral control algorithm, or a non-linear control algorithm.

[0036] In a possible implementation manner, the second control module is further configured to:

[0037] When switching the first specified control algorithm to the second specified control algorithm, use the voltage regulation value finally output by the first specified control algorithm as the initial value of the voltage regulation value of the second specified control algorithm.

[0038] In a possible implementation manner, the second control module is further configured to:

[0039] After switching the first specified control algorithm to the second specified control algorithm, when the DC voltage rises to the second DC lower limit threshold, switch the second specified control algorithm to the first specified control algorithm.

[0040] In a possible implementation manner, the second control module is further configured to:

[0041] When switching the second specified control algorithm to the first specified control algorithm, use the voltage regulation value finally output by the second specified control algorithm as the initial value of the voltage regulation value of the first specified control algorithm.

[0042] In a third aspect, a control circuit for a current source type converter is provided, and the control circuit includes a current source type converter and a controller;

[0043] The controller is configured to:

[0044] Detect the DC voltage output by the current source type converter;

[0045] When the DC voltage is greater than the DC upper limit threshold, control a plurality of controllable switching devices in the current source type converter to be turned off to disconnect the charging circuit of the DC bus capacitor in the current source type converter;

[0046] When the DC voltage is less than the first DC lower threshold, a drive control signal is determined, and based on the drive control signal, a plurality of controllable switch devices in the current source type converter are controlled.

[0047] In a possible implementation manner, the DC upper threshold is the sum of the DC voltage reference value and the upper fluctuation value, where the DC voltage reference value is the DC voltage that the target load driven by the current source type converter expects to input, and the upper fluctuation value is a positive value.

[0048] In a possible implementation manner, the DC lower threshold is the difference between the DC voltage reference value and the lower fluctuation value, where the DC voltage reference value is the DC voltage that the target load driven by the current source type converter expects to input, and the lower fluctuation value is a positive value.

[0049] In a possible implementation manner, the controller is configured to:

[0050] Determine a voltage regulation value based on the DC voltage reference value, the DC voltage, and the first specified control algorithm, where the DC voltage reference value is the DC voltage that the target load driven by the current source type converter expects to input;

[0051] Determine a drive control signal based on the voltage regulation value.

[0052] In a possible implementation manner, the controller is further configured to:

[0053] When the duration after controlling a plurality of controllable switch devices in the current source type converter based on the drive control signal reaches a preset duration, if the DC voltage is less than the second DC lower threshold, the first specified control algorithm is switched to the second specified control algorithm, where the second DC lower threshold is greater than the first DC lower threshold and less than the DC upper threshold.

[0054] In a possible implementation manner, the first specified control algorithm is a voltage-current double-loop control algorithm, and the second specified control algorithm is a voltage single-loop control algorithm, a proportional control algorithm, a proportional-integral control algorithm, or a nonlinear control algorithm.

[0055] In a possible implementation manner, the controller is further configured to:

[0056] When switching the first specified control algorithm to the second specified control algorithm, use the voltage regulation value finally output by the first specified control algorithm as the initial value of the voltage regulation value of the second specified control algorithm.

[0057] In a possible implementation manner, the controller is further configured to:

[0058] After switching the first specified control algorithm to the second specified control algorithm, when the DC voltage rises to the second DC lower threshold, switch the second specified control algorithm to the first specified control algorithm.

[0059] In a possible implementation, the controller is further configured to:

[0060] When switching the second specified control algorithm to the first specified control algorithm, use the voltage regulation value finally output by the second specified control algorithm as the initial value of the voltage regulation value of the first specified control algorithm.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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, it is possible to control multiple controllable switching devices to disconnect and stop charging the bus capacitor. During this process, the bus capacitor has been charging the load, thereby reducing the DC voltage, and further reducing the possibility of DC overvoltage protection events and events threatening the safety of the load, and improving the stability and safety of the load operation. Description of the Drawings

[0065] In order 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 drawings in the following description are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0066] Figure 1 is a topological schematic diagram of a current source type converter provided by an embodiment of the present disclosure;

[0067] Figure 2 is a flowchart of a control method of a current source type converter provided by an embodiment of the present disclosure;

[0068] Figure 3 is a flowchart of a method for determining a drive control signal provided by an embodiment of the present disclosure;

[0069] Figure 4 is a flowchart of a method for determining a drive control signal provided by an embodiment of the present disclosure;

[0070] 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;

[0071] Figure 6 is a block diagram of a structure of a terminal provided by an embodiment of the present disclosure;

[0072] Figure 7 is a block diagram of a structure of a server provided by an embodiment of the present disclosure. Detailed implementation manners

[0073] 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.

[0074] An embodiment of the present disclosure provides 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.

[0075] The computer device can include a processor, a memory, a communication component, etc.

[0076] The processor can be a central processing unit (CPU). The processor can be used to read instructions and process data. For example, it can detect the DC voltage output by the current source type converter, control multiple controllable switch devices in the current source type converter to turn off, determine a drive control signal, and control multiple controllable switch devices in the current source type converter based on the drive control signal, and so on.

[0077] 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 memory can be used for data storage. For example, it can store the data of the detected DC voltage output by the current source type converter, store the data of the DC upper limit threshold and the first DC lower limit threshold, store the data of the determined drive control signal, and so on.

[0078] 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 for data transmission with other devices.

[0079] See Figure 1 , Figure 1 is a topological schematic diagram of a current source type converter, where, v gabc is the three-phase AC voltage of the input current source type converter, V dc is the DC voltage output by the current source type converter, i dc is the output current of the current source type converter, C dc is the DC bus capacitor in the current source type converter. This current source type converter can convert three-phase alternating current into direct current, thereby forming a DC bus.

[0080] Figure 2 is a flowchart of a control method for a current source type converter provided by an embodiment of the present disclosure. See Figure 1 and Figure 2 , this embodiment includes:

[0081] 201. Detect the DC voltage output by the current source type converter.

[0082] In implementation, the DC voltage output by the current source type converter can be detected periodically, so as to obtain real-time and accurate DC voltage values.

[0083] 202. When the DC voltage is greater than the DC upper limit threshold, control multiple controllable switch devices in the current source type converter to disconnect, so as to disconnect the charging circuit of the DC bus capacitor in the current source type converter.

[0084] Among them, the DC upper limit threshold is a preset upper limit value of the DC voltage, so as to avoid the occurrence of DC overvoltage protection or events threatening the safety of the target load when the DC voltage exceeds the DC upper limit threshold.

[0085] In implementation, the latest detected DC voltage is compared with the pre-stored DC upper limit threshold. If the DC voltage is not greater than the DC upper limit threshold, it means that the power supply to the target load is normal at this time and no event of excessive DC voltage occurs. At this time, the drive control signal can be determined based on the input voltage (three-phase alternating current) and the DC voltage of the input current source type converter, and then multiple controllable switch devices in the current source type converter are controlled to work based on the drive control signal, so that the DC voltage can supply power to the target load normally.

[0086] If the DC voltage is greater than the DC upper threshold value, it indicates that there is a high probability that too much energy has accumulated in the DC bus capacitor under light load at this time. At this time, multiple controllable switch devices in the current source type converter can be controlled to disconnect, so as to disconnect the charging circuit of the DC bus capacitor in the current source type converter, enabling the DC bus capacitor to continuously discharge to supply power to the target load, thereby causing the DC voltage to gradually decrease, so as to avoid overvoltage protection or events that affect the normal operation of the target load.

[0087] Among them, the method of controlling multiple controllable switch devices in the current source type converter to disconnect can be to turn off the output of the drive control signal, that is, stop outputting the drive control signal to the multiple controllable switch devices, so that the controllable switch devices disconnect.

[0088] In a possible implementation manner, the above-mentioned DC upper threshold value can be the sum of the DC voltage reference value and the upper fluctuation value.

[0089] Among them, the DC voltage reference value is the DC voltage expected by the target load driven by the current source type converter. The DC voltage reference value can be preset through experimental results or calibrated when the target load leaves the factory. The specific acquisition method in the embodiments of the present disclosure is not limited.

[0090] The upper fluctuation value is a positive value. The upper fluctuation value can be set according to experimental results or experience to ensure that the value of the DC upper threshold can avoid overvoltage protection events and events that affect the normal operation of the target load. For example, the upper fluctuation value can be set to 5 volts, 3 volts, etc. The specific value in the embodiments of the present disclosure is not limited.

[0091] In a possible implementation manner, the controllable switch device can be any one of IGBT, Mosfet, and the combination of IGBT and diode in reverse parallel, or it can also be other reasonable switch devices. The embodiments of the present disclosure do not make specific limitations on this.

[0092] 203. When the DC voltage is less than the first DC lower threshold value, determine the drive control signal, and based on the drive control signal, control multiple controllable switch devices in the current source type converter.

[0093] In implementation, after controlling multiple controllable switch devices in the current source type converter to disconnect, since the charging of the DC bus capacitor has stopped and the DC bus capacitor is continuously discharging, the DC voltage will gradually decrease. When the DC voltage drops to less than the first DC lower threshold value, it indicates that the risk of excessive DC voltage has been lifted at this time and the target load can be powered normally. Therefore, the drive control signal can be determined at this time, and based on this drive control signal, multiple controllable switch devices in the current source type converter are controlled.

[0094] In a possible implementation, the DC lower threshold is the difference between the DC voltage reference value and the lower fluctuation value, where the DC voltage reference value is the DC voltage that the target load driven by the current source type converter expects to input, and the lower fluctuation value is a positive value.

[0095] The lower fluctuation value can be set according to experimental results or experience. For example, the lower fluctuation value can be set to 3 volts, 1 volt, etc., and the specific value thereof is not limited in the embodiments of the present disclosure.

[0096] In this way, through the above steps 201-203, the problem of excessive DC voltage can be detected in time, and the charging of the main bus capacitor can be stopped by controlling the disconnection of multiple controllable switching devices in the current source type converter, thereby reducing the DC voltage, and further reducing the possibility of DC overvoltage protection events and threats to the safety of the load, and improving the stability and safety of the load operation.

[0097] In a possible implementation, referring to Figure 3 , the method for determining the drive control signal may be: determining a voltage regulation value based on the DC voltage reference value, the DC voltage, and a first specified control algorithm, where the DC voltage reference value is the DC voltage that the target load driven by the current source type converter expects to input; determining the drive control signal based on the voltage regulation value.

[0098] In implementation, the DC voltage reference value and the DC voltage can be input into the first specified control algorithm to obtain the output voltage regulation value, and then the voltage regulation value and the three-phase AC voltage input into the current source type converter can be input into the modulation algorithm to obtain the output drive control signal.

[0099] Among them, the first specified control algorithm can be any reasonable control algorithm. For example, it can be a voltage-current double-loop control algorithm, etc., and the embodiments of the present disclosure do not limit this.

[0100] The control method of the current source type converter provided by the embodiments of the present disclosure, in addition to being able to perform the above processing to solve the problem of excessive DC voltage, when facing problems such as sudden changes in load power, large DC voltage drops caused by the inertia of small-capacity thin-film capacitors, and long DC voltage recovery times, also provides the following method:

[0101] Referring to Figure 4 , when the duration reaches a preset duration after controlling multiple controllable switching devices in the current source type converter based on the drive control signal, if the DC voltage is less than the second DC lower threshold, the first specified control algorithm is switched to the second specified control algorithm, where the second DC lower threshold is greater than the first DC lower threshold and less than the DC upper threshold.

[0102] In implementation, during the process of performing step 203 above, the drive control signal is continuously determined periodically, and multiple controllable switch devices are controlled based on the newly determined drive control signal. If the duration of controlling the multiple controllable switch devices based on the drive control signal reaches a preset duration and the DC voltage is less than the second DC lower limit threshold, it indicates that the DC voltage is recovering and the recovery speed of the DC voltage is slow. Then, the applied control algorithm can be changed, that is, the first specified control algorithm can be switched to the second specified control algorithm. Since the response speed of the second specified control algorithm is greater than that of the first specified control algorithm, the recovery efficiency of the DC voltage can be effectively improved, thereby ensuring the stable and efficient operation of the load.

[0103] Among them, the second DC lower limit threshold can be set according to requirements or actual situations, and can be set to a value slightly larger than the first DC lower limit threshold, etc. It can be the difference between the DC voltage reference value and the third fluctuation value, and the third fluctuation value is a positive value.

[0104] In a possible implementation manner, the first specified control algorithm can be a voltage-current double-loop control algorithm, and the second specified control algorithm can be any one of a voltage single-loop control algorithm, a proportional control algorithm, a proportional-integral control algorithm, or a non-linear control algorithm. Of course, the first specified control algorithm and the second specified control algorithm can also be any other reasonable algorithms, and the embodiments of the present disclosure do not limit this.

[0105] In a possible implementation manner, after switching the first specified control algorithm to the second specified control algorithm, when the DC voltage rises to the second DC lower limit threshold, the second specified control algorithm is switched to the first specified control algorithm.

[0106] Generally, the response speed of the second specified control algorithm is greater than that of the first specified control algorithm, but the output accuracy of the first specified control algorithm is greater than that of the second specified control algorithm. Therefore, when the DC voltage rises to the second DC lower limit threshold, it indicates that the DC voltage has recovered to a large extent at this time. At this time, the second specified control algorithm can be switched back to the first specified control algorithm, so that the output voltage adjustment value is more accurate, thereby making the DC voltage closer to the DC voltage reference value to ensure the stable operation of the target load.

[0107] In a possible implementation manner, when switching the first specified control algorithm to the second specified control algorithm, the voltage adjustment value finally output by the first specified control algorithm is used as the initial value of the voltage adjustment value of the second specified control algorithm.

[0108] In implementation, when the second specified control algorithm needs to perform integral processing on the voltage regulation value output each time, if the initial value of the voltage regulation value is not set, it defaults to zero. If the initial value of the voltage regulation value is zero, then when the first specified control algorithm switches to the second specified control algorithm, the adjustment speed of the second specified control algorithm will be relatively slow. Therefore, in the embodiments of the present disclosure, to avoid the above situation, the voltage regulation value finally output by the first specified control algorithm will be used as the initial value of the voltage regulation value of the second specified control algorithm (which can also be called pre-synchronization processing), thereby improving the rate of the second specified control algorithm.

[0109] Similarly, when switching the second specified control algorithm to the first specified control algorithm, the voltage regulation value finally output by the second specified control algorithm is used as the initial value of the voltage regulation value of the first specified control algorithm.

[0110] In this way, when the first specified control algorithm needs to perform integral processing on the voltage regulation value output each time, the voltage regulation value finally output by the second specified control algorithm can be pre-synchronized as the initial value of the voltage regulation value of the first specified control algorithm to improve the rate of the first specified control algorithm.

[0111] All the above optional technical solutions can be combined arbitrarily to form optional embodiments of the present disclosure, which will not be elaborated one by one here.

[0112] In the embodiments of the present disclosure, the proposed solution can be based on controlling multiple controllable switch devices to disconnect and stop charging the DC bus capacitor. During this process, the DC bus capacitor has been charging the load, thereby reducing the DC voltage, and further reducing the possibility of DC overvoltage protection events and threats to the safety of the load, improving the stability and safety of the load operation.

[0113] The embodiments of the present disclosure provide a control device for a current source type converter. The device can be the computer device in the above embodiments, such as Figure 5 shown, the device includes:

[0114] A detection module 510, configured to detect the DC voltage output by the current source type converter;

[0115] A first control module 520, configured to control multiple controllable switch devices in the current source type converter to disconnect when the DC voltage is greater than the DC upper threshold, so as to disconnect the charging circuit of the DC bus capacitor in the current source type converter;

[0116] A second control module 530, configured to determine a drive control signal when the DC voltage is less than the first DC lower threshold, and control multiple controllable switch devices in the current source type converter based on the drive control signal.

[0117] In a possible implementation, the DC upper threshold is the sum of the DC voltage reference value and the upper fluctuation value, where the DC voltage reference value is the DC voltage that the target load driven by the current source type converter expects to input, and the upper fluctuation value is a positive value.

[0118] In a possible implementation, the DC lower threshold is the difference between the DC voltage reference value and the lower fluctuation value, where the DC voltage reference value is the DC voltage that the target load driven by the current source type converter expects to input, and the lower fluctuation value is a positive value.

[0119] In a possible implementation, the second control module 530 is configured to:

[0120] Determine a voltage regulation value based on the DC voltage reference value, the DC voltage, and a first specified control algorithm, where the DC voltage reference value is the DC voltage that the target load driven by the current source type converter expects to input;

[0121] Determine a drive control signal based on the voltage regulation value.

[0122] In a possible implementation, the second control module 530 is further configured to:

[0123] When the duration after controlling a plurality of controllable switching devices in the current source type converter based on the drive control signal reaches a preset duration, if the DC voltage is less than a second DC lower threshold, switch the first specified control algorithm to a second specified control algorithm, where the second DC lower threshold is greater than the first DC lower threshold and less than the DC upper threshold.

[0124] In a possible implementation, the first specified control algorithm is a voltage-current double-loop control algorithm, and the second specified control algorithm is a voltage single-loop control algorithm, a proportional control algorithm, a proportional-integral control algorithm, or a non-linear control algorithm.

[0125] In a possible implementation, the second control module 530 is further configured to:

[0126] When switching the first specified control algorithm to the second specified control algorithm, use the voltage regulation value finally output by the first specified control algorithm as the initial value of the voltage regulation value of the second specified control algorithm.

[0127] In a possible implementation, the second control module 530 is further configured to:

[0128] After switching the first specified control algorithm to the second specified control algorithm, when the DC voltage rises to the second DC lower limit threshold, switch the second specified control algorithm to the first specified control algorithm.

[0129] In a possible implementation, the second control module 530 is further configured to:

[0130] When switching the second specified control algorithm to the first specified control algorithm, use the voltage regulation value finally output by the second specified control algorithm as the initial value of the voltage regulation value of the first specified control algorithm.

[0131] It should be noted that: when the control device of the current source type converter provided in the above embodiments controls the current source type converter, only the division of the above functional modules is used for illustration. In practical 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 embodiments and the embodiments of the control method of the current source type converter belong to the same concept. The specific implementation process can be found in the method embodiments and will not be repeated here.

[0132] An embodiment of the present disclosure provides a control circuit for a current source type converter. The control circuit includes a current source type converter and a controller;

[0133] The controller is configured to:

[0134] Detect the DC voltage output by the current source type converter;

[0135] When the DC voltage is greater than the DC upper limit threshold, control a plurality of controllable switch devices in the current source type converter to disconnect, so as to disconnect the charging circuit of the DC bus capacitor in the current source type converter;

[0136] When the DC voltage is less than the first DC lower limit threshold, determine a drive control signal, and based on the drive control signal, control a plurality of controllable switch devices in the current source type converter.

[0137] In a possible implementation, the DC upper limit threshold is the sum of the DC voltage reference value and the upper fluctuation value, where the DC voltage reference value is the DC voltage expected to be input by the target load driven by the current source type converter, and the upper fluctuation value is a positive value.

[0138] In a possible implementation, the DC lower threshold is the difference between the DC voltage reference value and the lower fluctuation value, where the DC voltage reference value is the DC voltage that the target load driven by the current source type converter expects to input, and the lower fluctuation value is a positive value.

[0139] In a possible implementation, the controller is configured to:

[0140] Determine a voltage regulation value based on the DC voltage reference value, the DC voltage, and a first specified control algorithm, where the DC voltage reference value is the DC voltage that the target load driven by the current source type converter expects to input;

[0141] Determine a drive control signal based on the voltage regulation value.

[0142] In a possible implementation, the controller is further configured to:

[0143] When the duration after controlling a plurality of controllable switching devices in the current source type converter based on the drive control signal reaches a preset duration, if the DC voltage is less than a second DC lower threshold, switch the first specified control algorithm to a second specified control algorithm, where the second DC lower threshold is greater than the first DC lower threshold and less than the DC upper threshold.

[0144] In a possible implementation, the first specified control algorithm is a voltage-current double-loop control algorithm, and the second specified control algorithm is a voltage single-loop control algorithm, a proportional control algorithm, a proportional-integral control algorithm, or a nonlinear control algorithm.

[0145] In a possible implementation, the controller is further configured to:

[0146] When switching the first specified control algorithm to the second specified control algorithm, use the voltage regulation value finally output by the first specified control algorithm as the initial value of the voltage regulation value of the second specified control algorithm.

[0147] In a possible implementation, the controller is further configured to:

[0148] After switching the first specified control algorithm to the second specified control algorithm, when the DC voltage rises to the second DC lower threshold, switch the second specified control algorithm to the first specified control algorithm.

[0149] In a possible implementation, the controller is further configured to:

[0150] When switching the second specified control algorithm to the first specified control algorithm, the voltage regulation value finally output by the second specified control algorithm is used as the initial value of the voltage regulation value of the first specified control algorithm.

[0151] Figure 6 FIG. 600 shows a structural block diagram of a terminal 600 provided by an exemplary embodiment of the present disclosure. 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 a user equipment, a portable terminal, a laptop terminal, a desktop terminal, etc.

[0152] Generally, the terminal 600 includes a processor 601 and a memory 602.

[0153] The processor 601 may include one or more processing cores, such as a 4-core processor, an 8-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), and PLA (Programmable Logic Array). The processor 601 may also include a main processor and a co-processor. The main processor is a processor for processing data in the wake state, also known as a CPU (Central Processing Unit); the co-processor is a low-power processor for processing 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.

[0154] The memory 602 may include one or more computer-readable storage media, which may be non-transitory. The memory 602 may also 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 for being 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.

[0155] 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 device includes 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.

[0156] The peripheral device interface 603 may be used to connect at least one peripheral device related to I / O (input / output) 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 may be implemented on a separate chip or circuit board, and the present embodiment does not limit this.

[0157] 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 a 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 may communicate with other terminals through at least one wireless communication protocol. The wireless communication protocol includes but is not limited to: a metropolitan area network, each generation of mobile communication networks (2G, 3G, 4G, and 5G), a wireless local area network, and / or a WiFi (wireless fidelity) network. In some embodiments, the radio frequency circuit 604 may further include a circuit related to NFC (near field communication), and the present disclosure does not limit this.

[0158] 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 a virtual keyboard, also known as soft buttons and / or a soft keyboard. 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 are in a folding 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 more, the display screen 605 can also be set to an irregular non-rectangular shape, that is, an irregular-shaped screen. The display screen 605 can be prepared using materials such as LCD (liquid crystal display) and OLED (organic light-emitting diode).

[0159] The camera module 606 is used to collect 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 implement functions such as background blurring by fusing the main camera and the depth-of-field camera, panoramic shooting by fusing the main camera and the wide-angle camera, and VR (virtual reality) shooting functions or other fused 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 dual-color-temperature flash. A dual-color-temperature flash refers to a combination of a warm light flash and a cold light flash, which can be used for light compensation under different color temperatures.

[0160] 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 implement 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 signals 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 electrical signals into audible sound waves for humans, but also convert electrical signals into inaudible sound waves for humans for uses such as ranging. In some embodiments, the audio circuit 607 may further include a headphone jack.

[0161] The positioning component 608 is used to locate the current geographical location of the terminal 600 to implement 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.

[0162] 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.

[0163] 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.

[0164] The acceleration sensor 611 can detect the magnitudes of accelerations 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.

[0165] The gyroscope sensor 612 can detect the body direction 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.

[0166] 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.

[0167] The fingerprint sensor 614 is used to collect the fingerprints of the user. The processor 601 can identify the user's identity based on the fingerprints collected by the fingerprint sensor 614, or the fingerprint sensor 614 can identify the user's identity based on the collected fingerprints. 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.

[0168] 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.

[0169] The proximity sensor 616, also known as the distance sensor, is usually 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.

[0170] 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 certain components, or adopt a different component arrangement.

[0171] 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 a wired or wireless network interface, a keyboard, and an input / output interface for input / output. The server may also include other components for implementing the functions of the device, which will not be elaborated here.

[0172] In an exemplary embodiment, a computer-readable storage medium is also provided, such as 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.

[0173] 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 related 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.

[0174] 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 relevant laws, regulations, and standards of relevant countries and regions. For example, the "DC voltage output by the current source type converter", "three-phase AC voltage", etc. involved in this disclosure are all obtained under full authorization.

[0175] The above are only optional embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of this disclosure shall be included within the protection scope of this disclosure.

Claims

1. A control method for a current source type converter, characterized in that, The method includes: Detecting the DC voltage output by the current source type converter; When the DC voltage is greater than the DC upper limit threshold, controlling multiple controllable switch devices in the current source type converter to disconnect, so as to disconnect the charging circuit of the DC bus capacitor in the current source type converter; When the DC voltage is less than the first DC lower limit threshold, determining a drive control signal, and based on the drive control signal, controlling multiple controllable switch devices in the current source type converter.

2. The method according to claim 1, wherein The DC upper limit threshold is the sum of the DC voltage reference value and the upper fluctuation value, where the DC voltage reference value is the DC voltage expected to be input by the target load driven by the current source type converter, and the upper fluctuation value is a positive value.

3. The method according to claim 1, characterized in that The DC lower limit threshold is the difference between the DC voltage reference value and the lower fluctuation value, where the DC voltage reference value is the DC voltage expected to be input by the target load driven by the current source type converter, and the lower fluctuation value is a positive value.

4. The method according to claim 1, wherein The determining the drive control signal includes: Determining a voltage regulation value based on the DC voltage reference value, the DC voltage, and the first specified control algorithm, where the DC voltage reference value is the DC voltage expected to be input by the target load driven by the current source type converter; Determining a drive control signal based on the voltage regulation value.

5. The method according to claim 4, wherein The method further includes: When the duration after controlling multiple controllable switch devices in the current source type converter based on the drive control signal reaches a preset duration, if the DC voltage is less than the second DC lower limit threshold, switching the first specified control algorithm to the second specified control algorithm, where the second DC lower limit threshold is greater than the first DC lower limit threshold and less than the DC upper limit threshold.

6. The method according to claim 5, wherein The first specified control algorithm is a voltage-current double-loop control algorithm, and the second specified control algorithm is a voltage single-loop control algorithm, a proportional control algorithm, a proportional-integral control algorithm, or a non-linear control algorithm.

7. The method according to claim 5, wherein The method further includes: When switching the first specified control algorithm to the second specified control algorithm, using the voltage regulation value finally output by the first specified control algorithm as the initial value of the voltage regulation value of the second specified control algorithm.

8. The method according to claim 5, characterized in that The method further includes: After switching the first specified control algorithm to the second specified control algorithm, when the DC voltage rises to the second DC lower limit threshold, switching the second specified control algorithm to the first specified control algorithm.

9. The method according to claim 8, characterized in that, The method further includes: When switching the second specified control algorithm to the first specified control algorithm, using the voltage regulation value finally output by the second specified control algorithm as the initial value of the voltage regulation value of the first specified control algorithm.

10. A control device for a current source type converter, characterized in that, The device includes: A detection module for detecting the DC voltage output by the current source type converter; A first control module for controlling multiple controllable switch devices in the current source type converter to disconnect when the DC voltage is greater than the DC upper limit threshold, so as to disconnect the charging circuit of the DC bus capacitor in the current source type converter; A second control module, configured to determine a drive control signal when the DC voltage is less than a first DC lower threshold, and control a plurality of controllable switch devices in the current source type converter based on the drive control signal.

11. 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: Detect the DC voltage output by the current source type converter; When the DC voltage is greater than a DC upper threshold, control the plurality of controllable switch devices in the current source type converter to be turned off, so as to disconnect the charging circuit of the DC bus capacitor in the current source type converter; When the DC voltage is less than a first DC lower threshold, determine a drive control signal, and control a plurality of controllable switch devices in the current source type converter based on the drive control signal.

12. 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 9.

13. 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 9.

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