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 steps of obtaining first comparison values corresponding to a plurality of first time points within a first preset duration, wherein the first comparison values corresponding to the first time points are the maximum value in line voltage absolute values of three-phase alternating current input into the current source type converter at the first time points; based on the minimum value in the first comparison values corresponding to the multiple first time points, a second comparison value is determined, and the second comparison value is not larger than the minimum value in the first comparison values corresponding to the multiple first time points; determining a minimum value between the second comparison value and a direct-current voltage expected value of a load driven by the current source type converter as a direct-current voltage reference value; and controlling the current source type converter based on the DC voltage reference value and the DC voltage output by the current source type converter. According to the invention, the normal operation of the load is ensured, and the stability of load operation is improved.

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 to supply power to some loads.

[0003] Generally, a current source type converter controls the conduction or shutdown of a plurality of controllable switching devices in the current source type converter based on a DC voltage reference value and the actually output DC voltage, so that the output DC voltage can approach the DC voltage reference value, thereby effectively supplying power to the load.

[0004] However, during the actual operation process, the three-phase alternating current input to the current source type converter may be interrupted or mutated, resulting in a sudden drop in the DC voltage. When the output DC voltage drops below the DC voltage reference value, the output capacity of the current source type converter cannot meet the DC voltage reference value, resulting in a drastic fluctuation in the DC voltage output to the load, affecting the normal operation of the load, and thus reducing the stability of the load operation. Summary of the Invention

[0005] An embodiment of the present disclosure provides a control method for a current source type converter, which can improve the stability 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] Obtain first comparison values corresponding to a plurality of first time points within a first preset duration, where the first comparison value corresponding to the first time point is the maximum value among the absolute values of the line voltages of the three-phase alternating current input to the current source type converter at the first time point;

[0008] Determine a second comparison value based on the minimum value among the first comparison values corresponding to the plurality of first time points, where the second comparison value is not greater than the minimum value among the first comparison values corresponding to the plurality of first time points;

[0009] Determine the minimum value between the second comparison value and the DC voltage expectation value of the load driven by the current source type converter as the DC voltage reference value;

[0010] Control the current source type converter based on the DC voltage reference value and the DC voltage output by the current source type converter.

[0011] In a possible implementation manner, determining a second comparison value based on the minimum value among the first comparison values corresponding to the multiple first time points includes:

[0012] Determining the minimum value among the first comparison values corresponding to the multiple first time points to obtain the second comparison value.

[0013] In a possible implementation manner, determining a second comparison value based on the minimum value among the first comparison values corresponding to the multiple first time points includes:

[0014] Taking the product of the minimum value among the first comparison values corresponding to the multiple first time points and a preset proportionality coefficient as the second comparison value, where the preset proportionality coefficient is a positive value less than 1.

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

[0016] If the DC voltage reference value is less than the DC voltage expected value, obtaining third comparison values corresponding to multiple second time points within a second preset duration, where the second preset duration is greater than half of the fundamental wave period of the three-phase alternating current;

[0017] If the minimum value among the third comparison values corresponding to the multiple second time points is greater than the minimum value among the first comparison values corresponding to the multiple first time points, determining a fourth comparison value based on the minimum value among the third comparison values corresponding to the multiple second time points;

[0018] Taking the minimum value between the fourth comparison value and the DC voltage expected value of the load driven by the current source type converter as the DC voltage reference value corresponding to the second preset duration;

[0019] Determining at least one intermediate value between the DC voltage reference value corresponding to the second preset duration and the previously determined DC voltage reference value;

[0020] Controlling the current source type converter based on the at least one intermediate value and the DC voltage.

[0021] In a possible implementation manner, determining at least one intermediate value between the DC voltage reference value corresponding to the second preset duration and the previously determined DC voltage reference value includes:

[0022] Performing low-pass filtering on the DC voltage reference value and the previously determined DC voltage reference value to obtain the at least one intermediate value.

[0023] In a possible implementation manner, determining at least one intermediate value between the DC voltage reference value corresponding to the second preset duration and the previously determined DC voltage reference value includes:

[0024] Based on a preset numerical spacing, obtain at least one intermediate value between the DC voltage reference value and the previously determined DC voltage reference value.

[0025] In a possible implementation, the method further includes: performing low-pass filtering on the three-phase alternating current.

[0026] In a possible implementation, the controllable switching device in the current source type converter is any one of an IGBT (Insulated Gate Bipolar Transistor), a Mosfet (Metal Oxide Semiconductor Field Effect Transistor), and a combination of an IGBT and a diode in reverse parallel.

[0027] In a second aspect, a control device for a current source type converter is provided, and the device includes:

[0028] An acquisition module, configured to acquire first comparison values corresponding to a plurality of first time points within a first preset duration, where the first comparison value corresponding to the first time point is the maximum value among the absolute values of the line voltages of the three-phase alternating current input to the current source type converter at the first time point;

[0029] A first determination module, configured to determine a second comparison value based on the minimum value among the first comparison values corresponding to the plurality of first time points, where the second comparison value is not greater than the minimum value among the first comparison values corresponding to the plurality of first time points;

[0030] A second determination module, configured to determine the minimum value between the second comparison value and the DC voltage expectation value of the load driven by the current source type converter as the DC voltage reference value;

[0031] A control module, configured to control the current source type converter based on the DC voltage reference value and the DC voltage output by the current source type converter.

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

[0033] Determine the minimum value among the first comparison values corresponding to the plurality of first time points to obtain the second comparison value.

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

[0035] Determine the product of the minimum value among the first comparison values corresponding to the multiple first time points and a preset proportionality coefficient as the second comparison value, where the preset proportionality coefficient is a positive value less than 1.

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

[0037] If the DC voltage reference value is less than the DC voltage expected value, obtain third comparison values corresponding to multiple second time points within a second preset duration, where the second preset duration is greater than half of the fundamental wave period of the three-phase alternating current;

[0038] If the minimum value among the third comparison values corresponding to the multiple second time points is greater than the minimum value among the first comparison values corresponding to the multiple first time points, determine a fourth comparison value based on the minimum value among the third comparison values corresponding to the multiple second time points;

[0039] Determine the minimum value between the fourth comparison value and the DC voltage expected value of the load driven by the current source type converter as the DC voltage reference value corresponding to the second preset duration;

[0040] Determine at least one intermediate value between the DC voltage reference value corresponding to the second preset duration and the previously determined DC voltage reference value;

[0041] Control the current source type converter based on the at least one intermediate value and the DC voltage.

[0042] In a possible implementation manner, the control module is configured to:

[0043] Perform low-pass filtering on the DC voltage reference value and the previously determined DC voltage reference value to obtain the at least one intermediate value.

[0044] In a possible implementation manner, the control module is configured to:

[0045] Obtain at least one intermediate value between the DC voltage reference value and the previously determined DC voltage reference value based on a preset numerical interval.

[0046] In a possible implementation manner, the control module is further configured to: perform low-pass filtering on the three-phase alternating current.

[0047] In a possible implementation, the controllable switch device in the current source type converter is any one of an IGBT (Insulated Gate Bipolar Transistor), a Mosfet (Metal Oxide Semiconductor Field Effect Transistor), and a combination of an IGBT and a diode in reverse parallel.

[0048] 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.

[0049] The controller is configured to:

[0050] Obtain first comparison values corresponding to a plurality of first time points within a first preset duration, where the first comparison value corresponding to the first time point is the maximum value among the absolute values of the line voltages of the three-phase alternating current input to the current source type converter at the first time point;

[0051] Determine a second comparison value based on the minimum value among the first comparison values corresponding to the plurality of first time points, where the second comparison value is not greater than the minimum value among the first comparison values corresponding to the plurality of first time points;

[0052] Determine the minimum value between the second comparison value and the expected value of the DC voltage of the load driven by the current source type converter as the DC voltage reference value;

[0053] Control the current source type converter based on the DC voltage reference value and the DC voltage output by the current source type converter.

[0054] In a possible implementation, the controller is configured to:

[0055] Determine the minimum value among the first comparison values corresponding to the plurality of first time points to obtain the second comparison value.

[0056] In a possible implementation, the controller is configured to:

[0057] Determine the product of the minimum value among the first comparison values corresponding to the plurality of first time points and a preset proportionality coefficient as the second comparison value, where the preset proportionality coefficient is a positive value less than 1.

[0058] In a possible implementation, the controller is further configured to:

[0059] If the DC voltage reference value is less than the DC voltage expected value, obtain third comparison values corresponding to a plurality of second time points within a second preset duration, where the second preset duration is greater than half of a fundamental wave period of the three-phase alternating current;

[0060] If the minimum value among the third comparison values corresponding to the plurality of second time points is greater than the minimum value among the first comparison values corresponding to the plurality of first time points, determine a fourth comparison value based on the minimum value among the third comparison values corresponding to the plurality of second time points;

[0061] Determine the minimum value between the fourth comparison value and the DC voltage expected value of the load driven by the current source type converter as the DC voltage reference value corresponding to the second preset duration;

[0062] Determine at least one intermediate value between the DC voltage reference value corresponding to the second preset duration and the previously determined DC voltage reference value;

[0063] Control the current source type converter based on the at least one intermediate value and the DC voltage.

[0064] In a possible implementation manner, the controller is configured to:

[0065] Perform low-pass filtering on the DC voltage reference value and the previously determined DC voltage reference value to obtain the at least one intermediate value.

[0066] In a possible implementation manner, the controller is configured to:

[0067] Obtain at least one intermediate value between the DC voltage reference value and the previously determined DC voltage reference value based on a preset numerical interval.

[0068] In a possible implementation manner, the control module is further configured to: perform low-pass filtering on the three-phase alternating current.

[0069] In a possible implementation manner, the controllable switch device in the current source type converter is any one of an IGBT (Insulated Gate Bipolar Transistor), a Mosfet (Metal Oxide Semiconductor Field Effect Transistor), and a combination of an IGBT and a diode in reverse parallel.

[0070] Fourthly, a computer device is provided, which 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.

[0071] Fifthly, 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.

[0072] Sixthly, 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.

[0073] 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, the second comparison value determined by the maximum value of the absolute value of the line voltage reflects to a certain extent the ability of the current source type converter to output direct current voltage. If the second comparison value is less than the direct current voltage reference value, it indicates that a situation of sudden drop in direct current voltage has occurred. Taking the second comparison value as the new direct current voltage reference value can avoid the occurrence of the situation where the output ability of the current source type converter cannot meet the direct current voltage reference value, thereby ensuring the normal operation of the load and improving the stability of the load operation. Description of the Drawings

[0074] 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 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.

[0075] Figure 1 is a schematic circuit topology diagram of a current source type converter provided by an embodiment of the present disclosure;

[0076] Figure 2 is a flowchart of a control method of a current source type converter provided by an embodiment of the present disclosure;

[0077] Figure 3 is a schematic diagram of the change of a first comparison value provided by an embodiment of the present disclosure;

[0078] Figure 4 is a flowchart of a control method of a current source type converter provided by an embodiment of the present disclosure;

[0079] Figure 5 is a flowchart of a control method of a current source type converter provided by an embodiment of the present disclosure;

[0080] Figure 6 It is a schematic structural diagram of a control device for a current source type converter provided by an embodiment of the present disclosure;

[0081] Figure 7 It is a block diagram of the structure of a terminal provided by an embodiment of the present disclosure;

[0082] Figure 8 It is a block diagram of the structure of a server provided by an embodiment of the present disclosure. Detailed implementation manners

[0083] To make the purpose, 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.

[0084] Refer to Figure 1 , Figure 1 is a schematic circuit topology diagram of a current source type converter, where v gabc is the current voltage of three phases in three-phase alternating current, and V dc is the DC voltage. This current source type converter can convert three-phase alternating current into direct current to supply power to the load driven by the current source type converter.

[0085] Figure 2 It 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:

[0086] 201. Obtain first comparison values corresponding to multiple first time points within a first preset duration.

[0087] In implementation, the first comparison values corresponding to multiple first time points within the first preset duration can be obtained periodically. This period can be the control period of the current source converter and can be set according to actual situations.

[0088] Among them, the first comparison value corresponding to the first time point is the maximum value among the absolute values of the line voltages of the three-phase alternating current input to the current source type converter at the first time point, that is: when the current source type converter is applied, its input is three-phase alternating current and its output is DC voltage. The first comparison value corresponding to the first time point is the maximum value among the absolute values of the line voltages |v gab |, |v gbc |, |v gac | of the three-phase alternating current at the first time point. Refer to Figure 3 , Figure 3 in which V e is the envelope formed by the first comparison values corresponding to multiple first time points.

[0089] Since the current source type converter is a buck converter, the first comparison value corresponding to the determined first time point can reflect the maximum output capability of the current source type converter at this first time point, that is, the numerical value of the first comparison value limits the numerical value of the DC voltage.

[0090] 202. Determine a second comparison value based on the minimum value among the first comparison values corresponding to multiple first time points.

[0091] Wherein, the second comparison value is not greater than the minimum value among the first comparison values corresponding to multiple first time points.

[0092] In implementation, since the current source type converter is a buck converter, therefore, a second comparison value not greater than the minimum value among multiple first comparison values can be determined according to the actual situation, so that the second comparison value can more accurately reflect the actual output capability of the current source type converter.

[0093] There can be various methods for determining the second comparison value based on the first comparison value.

[0094] In a possible implementation manner, the minimum value among the first comparison values corresponding to multiple first time points can be determined (see V Figure 3 in eMin ), and this minimum value is directly determined as the second comparison value.

[0095] The minimum value among the first comparison values corresponding to the multiple first time points corresponds to the lowest DC voltage after the sudden drop of the DC voltage within the first preset duration. Therefore, directly using the minimum value among the first comparison values corresponding to the multiple first time points as the second comparison value can reflect that the output capability of this current source type converter has suddenly dropped, thus providing a reference for subsequent determination of the DC voltage reference value.

[0096] In another possible implementation manner, the product of the minimum value among the first comparison values corresponding to multiple first time points and a preset proportionality coefficient can be determined as the second comparison value, where the preset proportionality coefficient is a positive value less than 1.

[0097] In implementation, the minimum value among the first comparison values corresponding to multiple first time points can be determined first, and then this minimum value is multiplied by the preset proportionality coefficient to obtain a value less than this minimum value, which is the second comparison value. In this way, the preset proportionality coefficient can be set based on the actual situation of the buck converter of the current source type converter, so as to obtain a value that can more accurately reflect the DC voltage output capability, that is, the obtained second comparison value can more accurately reflect the DC voltage output capability, providing a more accurate reference for subsequent determination of the DC voltage reference value.

[0098] Among them, the preset proportional coefficient can be any reasonable value. For example, it can be values such as 0.95, 0.92, 0.85, etc. The embodiments of the present disclosure do not make specific limitations on this.

[0099] In another possible implementation, the difference between the minimum value among the first comparison values corresponding to multiple first time points and the preset adjustment value can be determined as the second comparison value.

[0100] In implementation, the minimum value among the first comparison values corresponding to multiple first time points can be determined first, and then the difference between this minimum value and the preset adjustment value can be determined as the second comparison value. Among them, the preset adjustment value can be set based on the actual situation of the current source type converter, which is a buck converter, so as to obtain a second comparison value that can more accurately reflect the DC voltage output ability, providing a more accurate reference for determining the DC voltage reference value subsequently.

[0101] In addition to the several methods listed above for determining the second comparison value based on the first comparison value, other reasonable methods can also be used. The embodiments of the present disclosure do not make limitations on this.

[0102] 203. Determine the minimum value between the second comparison value and the DC voltage expectation value of the load driven by the current source type converter as the DC voltage reference value.

[0103] Among them, the DC voltage expectation value is a fixed value determined based on the load, which can be obtained through the factory parameters of the load or through experiments. The embodiments of the present disclosure do not make limitations on this.

[0104] If the second comparison value is greater than or equal to the DC voltage expectation value, the DC voltage expectation value is still determined as the DC voltage reference value. This DC voltage expectation value is the required voltage value of the load. Based on this DC voltage expectation value, controlling the current source type converter can enable the DC voltage output by the current source type converter to effectively provide drive for the load.

[0105] If the second comparison value is less than the DC voltage expectation value, it indicates that a situation of DC voltage sudden drop has occurred. At this time, the relatively small second comparison value can be determined as the DC voltage reference value, avoiding the situation that the output ability of the current source type converter cannot meet the DC voltage reference value, thus ensuring the normal operation of the load and improving the stability of the load operation.

[0106] 204. Control the current source type converter based on the DC voltage reference value and the DC voltage output by the current source type converter.

[0107] In implementation, the DC voltage reference value is the voltage value required by the load and that can be normally output by the current source type converter. Based on the DC voltage reference value and the actually output DC voltage, switching control is performed on multiple controllable switching devices in the current source type converter, so that the output DC voltage can be closer to the DC voltage reference value.

[0108] In a possible implementation manner, referring to Figure 4 , the DC voltage expected value V default and the three-phase alternating current V gabc are input into the DC voltage reference value setting algorithm (i.e., the above-mentioned steps 201-203), so as to obtain the DC voltage reference value V dcref . The DC voltage reference value V dcref is input into the voltage-current closed-loop control algorithm, and the modulation reference signal V ref is output. The modulation reference signal V ref and the three-phase alternating current V gabc are input into the modulation algorithm, so as to output a drive control signal. Based on this drive control signal, multiple controllable switching devices in the current source type converter are controlled to be turned off or on, so that the output DC voltage can be closer to the DC voltage reference value.

[0109] In a possible implementation manner, low-pass filtering processing can also be performed on the three-phase alternating current, so that the change of the three-phase alternating current is slower and smoother, that is, so that Figure 3 the envelope line in changes slower and smoother, thereby improving the stability and accuracy of the control process, improving the control performance, and further making the finally obtained second comparison value more accurate.

[0110] Further, each time after determining the minimum value among the first comparison values corresponding to multiple first time points through the three-phase alternating current, real-time low-pass filtering processing can be performed on this minimum value, so that the minimum value obtained after the low-pass filtering processing is between the current actual minimum value and the minimum value of the previous moment, that is, the minimum value obtained after the low-pass filtering processing will be a little larger than the current actual minimum value. Then, based on the minimum value obtained after the low-pass filtering processing, the second comparison value is determined. In this way, the value of the minimum value determined each time (i.e., Figure 3 the V eMin in) changes relatively slowly and smoothly with time, thereby improving the stability and accuracy of the control process, improving the control performance, and further making the finally obtained second comparison value more accurate.

[0111] In a possible implementation manner, the controllable switching device in the current source type converter can be any one of IGBT, Mosfet, and the combination of IGBT and diode in reverse parallel.

[0112] In the embodiment of the present disclosure, the second comparison value determined by the maximum value of the line voltage absolute value reflects to a certain extent the ability of the current source type converter to output a DC voltage. If the second comparison value is less than the DC voltage reference value, it indicates that a DC voltage dip has occurred. Taking the second comparison value as the new DC voltage reference value can avoid the situation where the output ability of the current source type converter cannot meet the DC voltage reference value, thus ensuring the normal operation of the load and improving the stability of the load operation.

[0113] The above introduces the method for determining a DC voltage reference value that can change with the actual situation when the DC voltage drops due to the interruption or mutation of three-phase alternating current. Conversely, when the interrupted or mutated three-phase alternating current gradually returns to normal, the current source type converter can still be controlled through the above steps 201-204, or it can be controlled by other methods. Below, see Figure 5 , and introduce this other method:

[0114] 501. If the DC voltage reference value is less than the DC voltage expected value, obtain the third comparison values corresponding to multiple second time points within a second preset duration.

[0115] In implementation, if the determined DC voltage reference value is less than the DC voltage expected value, it indicates that the process of interruption or mutation of three-phase alternating current is in progress at this time. Therefore, the third comparison values corresponding to multiple second time points within the second preset duration can be sampled.

[0116] Among them, the third comparison value corresponding to the second time point is the maximum value of the absolute values of the line voltages of the three-phase alternating current input to the current source type converter at the second time point.

[0117] The second preset duration is greater than half of the fundamental wave period of the three-phase alternating current. It can be understood that at least half of the fundamental wave period can more accurately reflect the numerical change of the three-phase alternating current. Therefore, obtaining the data of the second preset duration at this time provides an accurate reference for determining whether the three-phase alternating current is returning to normal subsequently.

[0118] 502. If the minimum value among the third comparison values corresponding to multiple second time points is greater than the minimum value among the first comparison values corresponding to multiple first time points, determine a fourth comparison value based on the minimum value among the third comparison values corresponding to multiple second time points.

[0119] In implementation, when the minimum value among the third comparison values corresponding to multiple second time points is greater than the minimum value among the first comparison values corresponding to multiple first time points, it indicates that the maximum value of the absolute value of the line voltage of the three-phase alternating current is increasing with time at this time, representing that the three-phase alternating current is returning to normal.

[0120] At this time, the fourth comparison value can be determined based on the minimum value among the third comparison values corresponding to multiple second time points. The determination method is similar to that in step 202 above. For example, the minimum value among the third comparison values corresponding to multiple second time points can be directly determined as the fourth comparison value, or the product of the minimum value among the third comparison values corresponding to multiple second time points and a preset proportional coefficient can be determined as the fourth comparison value, etc. The embodiments of the present disclosure do not limit this.

[0121] 503. Determine the minimum value between the fourth comparison value and the expected DC voltage of the load driven by the current source type converter as the DC voltage reference value corresponding to the second preset duration.

[0122] If the fourth comparison value is greater than or equal to the expected DC voltage, the expected DC voltage is still determined as the DC voltage reference value. This expected DC voltage is the required voltage value of the load. Controlling the current source type converter based on this expected DC voltage can enable the DC voltage output by the current source type converter to effectively provide drive for the load.

[0123] If the fourth comparison value is less than the expected DC voltage, it indicates that the line voltage of the three-phase alternating current is still relatively low and the DC voltage output ability of the current source type converter is poor. At this time, the relatively small fourth comparison value can be determined as the DC voltage reference value, avoiding the situation where the output ability of the current source type converter cannot meet the DC voltage reference value, thus ensuring the normal operation of the load and improving the stability of the load operation. See Figure 3 , Figure 3 The V in eMinT is the DC voltage reference value corresponding to the second preset duration.

[0124] 504. Determine at least one intermediate value between the DC voltage reference value corresponding to the second preset duration and the previously determined DC voltage reference value.

[0125] Since it has been determined in step 502 that the current is during the recovery period of the three-phase alternating current, at this time, at least one intermediate value can be selected, and the current source type converter can be controlled based on this intermediate value. In this way, on the one hand, since the intermediate value is less than the DC voltage reference value, controlling the current source type converter based on the intermediate value and the DC voltage will not result in the situation where the output ability of the current source type converter cannot meet the DC voltage reference value, ensuring the normal operation of the load. On the other hand, controlling the current source type converter based on at least one intermediate value can avoid the situation of unstable DC voltage output caused by a sudden increase in the DC voltage reference value. The at least one intermediate value realizes a slow change between the DC voltage reference value corresponding to the second preset duration and the previous DC voltage reference value, thereby improving the stability of the load operation.

[0126] 505. Control a current source type converter based on at least one intermediate value and a DC voltage.

[0127] In implementation, at least one intermediate value and a DC voltage reference value corresponding to a second preset duration can be sorted in ascending order of numerical value, and the current source type converter can be controlled in this order, so as to realize a slow change of the DC voltage and improve the stability of the load operation.

[0128] In step 504, there can be various methods for determining the intermediate value.

[0129] In a possible implementation manner, a low-pass filtering process can be performed on the DC voltage reference value and the previously determined DC voltage reference value to obtain at least one intermediate value.

[0130] In another possible implementation manner, at least one intermediate value between the DC voltage reference value and the previously determined DC voltage reference value can be obtained based on a preset numerical interval.

[0131] In implementation, the sum of the previously determined DC voltage reference value and the preset numerical interval is determined as an intermediate value, and the current source type converter is controlled based on this intermediate value and the DC voltage. Then, a preset numerical interval is added to the determined intermediate value to obtain the next intermediate value, and the current source type converter is controlled based on this intermediate value and the DC voltage. Until the value after adding a preset numerical interval to the determined intermediate value exceeds the DC voltage reference value corresponding to the second preset duration, then this value is discarded, and the current source type converter is directly controlled based on the DC voltage reference value corresponding to the second preset duration and the DC voltage.

[0132] Through the above steps 501 - 505, the control during the process of restoring the three-phase alternating current to normal is smoother, avoiding output fluctuations caused by mutations, thereby improving the stability of the load operation.

[0133] 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.

[0134] The beneficial effects brought by the technical solutions provided in the embodiments of the present disclosure are: in the solutions mentioned in the embodiments of the present disclosure, the second comparison value determined by the maximum value of the line voltage absolute value reflects to a certain extent the ability of the current source type converter to output DC voltage. If the second comparison value is less than the DC voltage reference value, it indicates that a situation of sudden drop in DC voltage has occurred. Taking the second comparison value as the new DC voltage reference value avoids the occurrence of the situation where the output ability of the current source type converter cannot meet the DC voltage reference value, thereby ensuring the normal operation of the load and improving the stability of the load operation.

[0135] An embodiment of the present disclosure provides a control device for a current source type converter, and the device may be the computer device in the above embodiment, such as Figure 6 shown, the device includes:

[0136] An acquisition module 610, configured to acquire first comparison values corresponding to a plurality of first time points within a first preset duration, wherein the first comparison value corresponding to the first time point is the maximum value among the absolute values of the line voltages of the three-phase alternating current input to the current source type converter at the first time point;

[0137] A first determination module 620, configured to determine a second comparison value based on the minimum value among the first comparison values corresponding to the plurality of first time points, wherein the second comparison value is not greater than the minimum value among the first comparison values corresponding to the plurality of first time points;

[0138] A second determination module 630, configured to determine the minimum value between the second comparison value and the expected value of the DC voltage of the load driven by the current source type converter as the DC voltage reference value;

[0139] A control module 640, configured to control the current source type converter based on the DC voltage reference value and the DC voltage output by the current source type converter.

[0140] In a possible implementation manner, the first determination module 620 is configured to:

[0141] Determine the minimum value among the first comparison values corresponding to the plurality of first time points to obtain the second comparison value.

[0142] In a possible implementation manner, the first determination module 620 is configured to:

[0143] Determine the product of the minimum value among the first comparison values corresponding to the plurality of first time points and a preset proportionality coefficient as the second comparison value, wherein the preset proportionality coefficient is a positive value less than 1.

[0144] In a possible implementation manner, the control module 640 is further configured to:

[0145] If the DC voltage reference value is less than the DC voltage expected value, acquire third comparison values corresponding to a plurality of second time points within a second preset duration, wherein the second preset duration is greater than half of the fundamental wave period of the three-phase alternating current;

[0146] If the minimum value among the third comparison values corresponding to the multiple second time points is greater than the minimum value among the first comparison values corresponding to the multiple first time points, determine a fourth comparison value based on the minimum value among the third comparison values corresponding to the multiple second time points;

[0147] Determine the minimum value between the fourth comparison value and the expected DC voltage of the load driven by the current source type converter as the DC voltage reference value corresponding to the second preset duration;

[0148] Determine at least one intermediate value between the DC voltage reference value corresponding to the second preset duration and the previously determined DC voltage reference value;

[0149] Control the current source type converter based on the at least one intermediate value and the DC voltage.

[0150] In a possible implementation, the control module 640 is configured to:

[0151] Perform low-pass filtering on the DC voltage reference value and the previously determined DC voltage reference value to obtain the at least one intermediate value.

[0152] In a possible implementation, the control module 640 is configured to:

[0153] Obtain at least one intermediate value between the DC voltage reference value and the previously determined DC voltage reference value based on a preset numerical interval.

[0154] In a possible implementation, the control module is further configured to: perform low-pass filtering on the three-phase alternating current.

[0155] In a possible implementation, the controllable switching device in the current source type converter is any one of an IGBT (Insulated Gate Bipolar Transistor), a Mosfet (Metal Oxide Semiconductor Field Effect Transistor), and a combination of an IGBT and a diode in reverse parallel.

[0156] 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 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 embodiments and the embodiments of the control method of the current source type converter belong to the same concept. For the specific implementation process, please refer to the method embodiments, which will not be elaborated here.

[0157] Figure 7 FIG. shows a block diagram of a terminal 700 provided by an exemplary embodiment of the present disclosure. The terminal may be the computer device in the above embodiments. The terminal 700 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 notebook computer, or a desktop computer. The terminal 700 may also be referred to by other names such as a user equipment, a portable terminal, a laptop terminal, a desktop terminal, etc.

[0158] Generally, the terminal 700 includes a processor 701 and a memory 702.

[0159] The processor 701 may include one or more processing cores, such as a quad-core processor, an octa-core processor, etc. The processor 701 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 701 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the wake state, also known as the CPU (central processing unit); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 701 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 701 may further include an AI (artificial intelligence) processor, and the AI processor is used to process computational operations related to machine learning.

[0160] The memory 702 may include one or more computer-readable storage media, and the computer-readable storage media may be non-transitory. The memory 702 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 702 is used to store at least one instruction, and the at least one instruction is used to be executed by the processor 701 to implement the control method of the current source type converter provided in the method embodiments of the present disclosure.

[0161] In some embodiments, the terminal 700 may further optionally include: a peripheral device interface 703 and at least one peripheral device. The processor 701, the memory 702, and the peripheral device interface 703 may be connected by a bus or signal lines. Each peripheral device may be connected to the peripheral device interface 703 through a bus, signal lines, or a circuit board. Specifically, the peripheral devices include at least one of a radio frequency circuit 704, a display screen 705, a camera 706, an audio circuit 707, a positioning component 708, and a power supply 709.

[0162] The peripheral device interface 703 can be used to connect at least one I / O (input / output) related peripheral device to the processor 701 and the memory 702. In some embodiments, the processor 701, the memory 702, and the peripheral device interface 703 are integrated on the same chip or circuit board; in some other embodiments, any one or two of the processor 701, the memory 702, and the peripheral device interface 703 can be implemented on a separate chip or circuit board, and this embodiment does not limit this.

[0163] The radio frequency circuit 704 is used to receive and transmit RF (radio frequency) signals, also known as electromagnetic signals. The radio frequency circuit 704 communicates with a communication network and other communication devices through electromagnetic signals. The radio frequency circuit 704 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 704 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 704 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, generations of mobile communication networks (2G, 3G, 4G, and 5G), wireless local area network, and / or WiFi (wireless fidelity) network. In some embodiments, the radio frequency circuit 704 may further include a circuit related to NFC (near field communication), and this disclosure does not limit this.

[0164] The display screen 705 is used to display the UI (user interface). The UI may include graphics, text, icons, videos, and any combination thereof. When the display screen 705 is a touch display screen, the display screen 705 also has the ability to collect touch signals on or above the surface of the display screen 705. The touch signal can be input to the processor 701 as a control signal for processing. At this time, the display screen 705 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 705, which is provided on the front panel of the terminal 700; in other embodiments, there may be at least two display screens 705, which are respectively provided on different surfaces of the terminal 700 or are in a foldable design; in still other embodiments, the display screen 705 may be a flexible display screen, which is provided on the curved surface or the folding surface of the terminal 700. Even more, the display screen 705 can also be set to an irregular non-rectangular shape, that is, a special-shaped screen. The display screen 705 can be prepared from materials such as LCD (liquid crystal display) and OLED (organic light-emitting diode).

[0165] The camera module 706 is used to collect images or videos. Optionally, the camera module 706 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, so as to realize the function of background blurring by fusing the main camera and the depth-of-field camera, the function of panoramic shooting by fusing the main camera and the wide-angle camera, and the VR (virtual reality) shooting function or other fused shooting functions. In some embodiments, the camera module 706 may also include a flash. The flash can be a single-color-temperature flash or a dual-color-temperature flash. The dual-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.

[0166] The audio circuit 707 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 701 for processing, or input to the radio frequency circuit 704 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 700. 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 701 or the radio frequency circuit 704 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 sound waves audible to humans, but also convert electrical signals into sound waves inaudible to humans for uses such as ranging. In some embodiments, the audio circuit 707 may further include a headphone jack.

[0167] The positioning component 708 is used to locate the current geographical location of the terminal 700 to implement navigation or LBS (location based service). The positioning component 708 may be a positioning component based on GPS (global positioning system), Beidou system, GLONASS system or Galileo system.

[0168] The power supply 709 is used to supply power to each component in the terminal 700. The power supply 709 may be alternating current, direct current, a disposable battery or a rechargeable battery. When the power supply 709 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.

[0169] In some embodiments, the terminal 700 further includes one or more sensors 710. The one or more sensors 710 include but are not limited to: an acceleration sensor 711, a gyroscope sensor 712, a pressure sensor 713, a fingerprint sensor 714, an optical sensor 715 and a proximity sensor 716.

[0170] The acceleration sensor 711 can detect the magnitudes of accelerations on the three coordinate axes of the coordinate system established with the terminal 700. For example, the acceleration sensor 711 can be used to detect the components of the gravitational acceleration on the three coordinate axes. The processor 701 can control the display screen 705 to display the user interface in a landscape view or a portrait view according to the gravitational acceleration signal collected by the acceleration sensor 711. The acceleration sensor 711 can also be used for collecting game or user's motion data.

[0171] The gyroscope sensor 712 can detect the body direction and rotation angle of the terminal 700. The gyroscope sensor 712 can cooperate with the acceleration sensor 711 to collect the 3D actions of the user on the terminal 700. Based on the data collected by the gyroscope sensor 712, the processor 701 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.

[0172] The pressure sensor 713 can be disposed on the side frame of the terminal 700 and / or the lower layer of the display screen 705. When the pressure sensor 713 is disposed on the side frame of the terminal 700, it can detect the holding signal of the user on the terminal 700, and the processor 701 can perform left / right hand recognition or shortcut operations according to the holding signal collected by the pressure sensor 713. When the pressure sensor 713 is disposed on the lower layer of the display screen 705, the processor 701 can control the operable controls on the UI interface according to the pressure operation of the user on the display screen 705. The operable controls include at least one of button controls, scroll bar controls, icon controls, and menu controls.

[0173] The fingerprint sensor 714 is used to collect the fingerprints of the user. The processor 701 can identify the user's identity according to the fingerprints collected by the fingerprint sensor 714, or the fingerprint sensor 714 can identify the user's identity according to the collected fingerprints. When the identified user identity is a trusted identity, the processor 701 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 714 can be disposed on the front, back, or side of the terminal 700. When there are physical buttons or manufacturer Logos on the terminal 700, the fingerprint sensor 714 can be integrated with the physical buttons or manufacturer Logos.

[0174] The optical sensor 715 is used to collect the ambient light intensity. In one embodiment, the processor 701 can control the display brightness of the display screen 705 according to the ambient light intensity collected by the optical sensor 715. Specifically, when the ambient light intensity is high, the display brightness of the display screen 705 is increased; when the ambient light intensity is low, the display brightness of the display screen 705 is decreased. In another embodiment, the processor 701 can also dynamically adjust the shooting parameters of the camera module 706 according to the ambient light intensity collected by the optical sensor 715.

[0175] The proximity sensor 716, also known as a distance sensor, is typically disposed on the front panel of the terminal 700. The proximity sensor 716 is used to collect the distance between the user and the front of the terminal 700. In one embodiment, when the proximity sensor 716 detects that the distance between the user and the front of the terminal 700 is gradually decreasing, the processor 701 controls the display screen 705 to switch from the lit state to the off state; when the proximity sensor 716 detects that the distance between the user and the front of the terminal 700 is gradually increasing, the processor 701 controls the display screen 705 to switch from the off state to the lit state.

[0176] Those skilled in the art can understand that Figure 7 the structure shown in does not constitute a limitation on the terminal 700, and may include more or fewer components than shown in the figure, or combine some components, or adopt a different component arrangement.

[0177] Figure 8 is a schematic structural diagram of a server provided by an embodiment of the present disclosure. The server 800 may vary greatly due to different configurations or performances, and may include one or more processors (central processing units, CPUs) 801 and one or more memories 802. Among them, at least one instruction is stored in the memory 802, and the at least one instruction is loaded and executed by the processor 801 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.

[0178] 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.

[0179] 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.

[0180] It should be noted that the information (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.) involved in this disclosure 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 "absolute value of the line voltage of the three-phase alternating current of the input current source type converter", "DC voltage output by the current source type converter", "DC voltage expected value", etc. involved in this disclosure are all obtained under full authorization.

[0181] 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: Obtaining first comparison values corresponding to multiple first time points within a first preset time period, where the first comparison value corresponding to the first time point is the maximum value among the absolute values of the line voltages of the three-phase alternating current input to the current source type converter at the first time point; Determining a second comparison value based on the minimum value among the first comparison values corresponding to the multiple first time points, where the second comparison value is not greater than the minimum value among the first comparison values corresponding to the multiple first time points; Determining the minimum value between the second comparison value and the expected value of the DC voltage of the load driven by the current source type converter as the DC voltage reference value; Controlling the current source type converter based on the DC voltage reference value and the DC voltage output by the current source type converter.

2. The method according to claim 1, characterized in that The determining the second comparison value based on the minimum value among the first comparison values corresponding to the multiple first time points includes: Determining the minimum value among the first comparison values corresponding to the multiple first time points to obtain the second comparison value.

3. The method according to claim 1, characterized in that, The determining the second comparison value based on the minimum value among the first comparison values corresponding to the multiple first time points includes: Determining the product of the minimum value among the first comparison values corresponding to the multiple first time points and a preset proportionality coefficient as the second comparison value, where the preset proportionality coefficient is a positive value less than 1.

4. The method according to claim 1, characterized in that, The method further includes: If the DC voltage reference value is less than the expected value of the DC voltage, obtaining third comparison values corresponding to multiple second time points within a second preset time period, where the second preset time period is greater than half of the fundamental wave period of the three-phase alternating current; If the minimum value among the third comparison values corresponding to the multiple second time points is greater than the minimum value among the first comparison values corresponding to the multiple first time points, determining a fourth comparison value based on the minimum value among the third comparison values corresponding to the multiple second time points; Determining the minimum value between the fourth comparison value and the expected value of the DC voltage of the load driven by the current source type converter as the DC voltage reference value corresponding to the second preset time period; Determining at least one intermediate value between the DC voltage reference value corresponding to the second preset time period and the previously determined DC voltage reference value; Controlling the current source type converter based on the at least one intermediate value and the DC voltage.

5. The method according to claim 4, wherein The determining at least one intermediate value between the DC voltage reference value corresponding to the second preset time period and the previously determined DC voltage reference value includes: Performing low-pass filtering on the DC voltage reference value and the previously determined DC voltage reference value to obtain the at least one intermediate value.

6. The method according to claim 4, characterized in that The determining at least one intermediate value between the DC voltage reference value corresponding to the second preset time period and the previously determined DC voltage reference value includes: Obtaining at least one intermediate value between the DC voltage reference value and the previously determined DC voltage reference value based on a preset numerical interval.

7. The method according to claim 1, wherein The method further includes: performing low-pass filtering on the three-phase alternating current.

8. The method according to claim 1, wherein The controllable switching device in the current source type converter is any one of an insulated gate bipolar transistor (IGBT), a metal oxide semiconductor field effect transistor (Mosfet), and a combination of an IGBT and a diode connected in antiparallel.

9. A control device for a current source type converter, characterized in that, The device includes: An acquisition module, configured to acquire first comparison values corresponding to a plurality of first time points within a first preset duration, where the first comparison value corresponding to the first time point is the maximum value among the absolute values of the line voltages of the three-phase alternating current input to the current source type converter at the first time point; A first determination module, configured to determine a second comparison value based on the minimum value among the first comparison values corresponding to the plurality of first time points, where the second comparison value is not greater than the minimum value among the first comparison values corresponding to the plurality of first time points; A second determination module, configured to determine the minimum value between the second comparison value and the expected value of the DC voltage of the load driven by the current source type converter as the DC voltage reference value; A control module, configured to control the current source type converter based on the DC voltage reference value and the DC voltage output by the current source type converter.

10. 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: Acquire first comparison values corresponding to a plurality of first time points within a first preset duration, where the first comparison value corresponding to the first time point is the maximum value among the absolute values of the line voltages of the three-phase alternating current input to the current source type converter at the first time point; Determine a second comparison value based on the minimum value among the first comparison values corresponding to the plurality of first time points, where the second comparison value is not greater than the minimum value among the first comparison values corresponding to the plurality of first time points; Determine the minimum value between the second comparison value and the expected value of the DC voltage of the load driven by the current source type converter as the DC voltage reference value; Control the current source type converter based on the DC voltage reference value and the DC voltage output by the current source type converter.

11. 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 8.

12. 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 8.

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