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 determining a maximum phase, a minimum phase and an intermediate phase based on current voltages of three phases in a three-phase alternating current; determining a first duty ratio corresponding to the maximum phase based on the current voltage of the maximum phase; determining a second duty ratio corresponding to the intermediate phase based on the current voltage of the intermediate phase; based on the second duty ratio corresponding to the intermediate phase, a third duty ratio corresponding to the minimum phase is determined, and the minimum phase and the intermediate phase complement each other; and based on the current three-phase voltage, the first duty ratio, the second duty ratio and the third duty ratio, controlling a plurality of controllable switching devices in the current source type converter to be switched on or switched off. According to the invention, the voltage stress is reduced, and the EMI performance 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 form a DC bus to supply power to some load devices.

[0003] Generally, the duty ratio corresponding to the maximum phase is calculated based on the voltage of the maximum phase, the duty ratio corresponding to the minimum phase is calculated based on the voltage of the minimum phase, and the middle phase is complementary to the minimum phase.

[0004] However, within each switching period of the above control process, the DC output voltage of the bridge arm will directly jump from zero to the line voltage between the middle phase and the maximum phase, and will also directly jump from the line voltage between the middle phase and the maximum phase to zero. The amplitude of the jump is relatively large, which easily causes resonance between the inductor and the capacitor, resulting in relatively large voltage stress and poor EMI (Electro Magnetic Compatibility) performance. Summary of the Invention

[0005] Embodiments of the present disclosure provide a control method for a current source type converter, which can reduce the amplitude of each jump of the DC output voltage of the bridge arm, thereby reducing the voltage stress and improving the EMI (Electro Magnetic Compatibility) performance. 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] Based on the current voltages of the three phases in the three-phase alternating current, determine the maximum phase, the minimum phase and the middle phase;

[0008] Based on the current voltage of the maximum phase, determine the first duty ratio corresponding to the maximum phase;

[0009] Based on the current voltage of the middle phase, determine the second duty ratio corresponding to the middle phase;

[0010] Based on the second duty ratio corresponding to the middle phase, determine the third duty ratio corresponding to the minimum phase, where the minimum phase is complementary to the middle phase;

[0011] Based on the first duty ratio, the second duty ratio and the third duty ratio, control the conduction or disconnection of a plurality of controllable switching devices in the current source type converter.

[0012] In a possible implementation, controlling the conduction or disconnection of multiple controllable switching devices in the current source type converter based on the first duty cycle, the second duty cycle, and the third duty cycle includes:

[0013] In any switching period, when the controllable switching device corresponding to the middle is in the off state, controlling the controllable switching device on the upper bridge arm corresponding to the minimum or the controllable switching device on the lower bridge arm corresponding to the minimum to be in the on state; when the controllable switching device corresponding to the middle is in the on state, controlling the controllable switching device on the upper bridge arm corresponding to the minimum and the controllable switching device on the lower bridge arm corresponding to the minimum to be in the off state.

[0014] In a possible implementation, controlling the conduction or disconnection of multiple controllable switching devices in the current source type converter based on the first duty cycle, the second duty cycle, and the third duty cycle includes:

[0015] In any switching period, when the controllable switching devices corresponding to the maximum and the middle are both in the off state, controlling the controllable switching devices on the upper bridge arm corresponding to the minimum and the controllable switching devices on the lower bridge arm corresponding to the minimum to be both in the on state; when the controllable switching device corresponding to the maximum is in the on state and the controllable switching device corresponding to the middle is in the off state, controlling the controllable switching device on the upper bridge arm corresponding to the minimum or the controllable switching device on the lower bridge arm corresponding to the minimum to be in the on state.

[0016] In a possible implementation, controlling the conduction or disconnection of multiple controllable switching devices in the current source type converter based on the first duty cycle, the second duty cycle, and the third duty cycle includes:

[0017] Based on the first duty cycle, controlling the controllable switching devices on the upper bridge arm corresponding to the maximum and the controllable switching devices on the lower bridge arm corresponding to the maximum to be both conducting or both disconnecting;

[0018] Based on the second duty cycle, controlling the controllable switching devices on the upper bridge arm corresponding to the middle and the controllable switching devices on the lower bridge arm corresponding to the middle to be both conducting or both disconnecting;

[0019] Based on the third duty cycle, controlling the controllable switching devices on the upper bridge arm corresponding to the minimum and the controllable switching devices on the lower bridge arm corresponding to the minimum to be both conducting or both disconnecting.

[0020] In a possible implementation, determining the first duty cycle corresponding to the maximum based on the current voltage of the maximum phase includes:

[0021] Determine a first duty cycle corresponding to the maximum phase based on the sum of squares of the current voltages of the three phases, the current voltage of the maximum phase, and the DC voltage.

[0022] In a possible implementation, the determining the second duty cycle corresponding to the intermediate phase based on the current voltage of the intermediate phase includes:

[0023] Determine the second duty cycle corresponding to the intermediate phase based on the sum of squares of the current voltages of the three phases, the current voltage of the intermediate phase, and the DC voltage.

[0024] In a possible implementation, the controllable switching device 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.

[0025] In a second aspect, a control device for a current source type converter is provided, and the device includes:

[0026] A first determination module, configured to determine a maximum phase, a minimum phase, and an intermediate phase based on the current voltages of the three phases in the three-phase alternating current;

[0027] A second determination module, configured to determine a first duty cycle corresponding to the maximum phase based on the current voltage of the maximum phase;

[0028] A third determination module, configured to determine a second duty cycle corresponding to the intermediate phase based on the current voltage of the intermediate phase;

[0029] A fourth determination module, configured to determine a third duty cycle corresponding to the minimum phase based on the second duty cycle corresponding to the intermediate phase, where the minimum phase and the intermediate phase are complementary;

[0030] A control module, configured to control multiple controllable switching devices in the current source type converter to conduct or disconnect based on the current voltages of the three phases, the first duty cycle, the second duty cycle, and the third duty cycle.

[0031] In a possible implementation, the control module is configured to:

[0032] In any switching period, when the controllable switching device corresponding to the middle phase is in the off state, control the controllable switching device on the upper bridge arm corresponding to the minimum phase or the controllable switching device on the lower bridge arm corresponding to the minimum phase to be in the on state; when the controllable switching device corresponding to the middle phase is in the on state, control the controllable switching device on the upper bridge arm corresponding to the minimum phase and the controllable switching device on the lower bridge arm corresponding to the minimum phase to be in the off state.

[0033] In a possible implementation, the control module is further configured to:

[0034] In any switching period, when the controllable switching devices corresponding to the maximum phase and the middle phase are both in the off state, control the controllable switching devices on the upper bridge arm corresponding to the minimum phase and the controllable switching devices on the lower bridge arm corresponding to the minimum phase to be both in the on state; when the controllable switching device corresponding to the maximum phase is in the on state and the controllable switching device corresponding to the middle phase is in the off state, control the controllable switching device on the upper bridge arm corresponding to the minimum phase or the controllable switching device on the lower bridge arm corresponding to the minimum phase to be in the on state.

[0035] In a possible implementation, the control module is configured to:

[0036] Based on the first duty cycle, control the controllable switching devices on the upper bridge arm corresponding to the maximum phase and the controllable switching devices on the lower bridge arm corresponding to the maximum phase to be both on or both off;

[0037] Based on the second duty cycle, control the controllable switching devices on the upper bridge arm corresponding to the middle phase and the controllable switching devices on the lower bridge arm corresponding to the middle phase to be both on or both off;

[0038] Based on the third duty cycle, control the controllable switching devices on the upper bridge arm corresponding to the minimum phase and the controllable switching devices on the lower bridge arm corresponding to the minimum phase to be both on or both off.

[0039] In a possible implementation, the second determination module is configured to:

[0040] Based on the sum of the squares of the current voltages of the three phases, the current voltage of the maximum phase, and the DC voltage, determine the first duty cycle corresponding to the maximum phase.

[0041] In a possible implementation, the third determination module is configured to:

[0042] Based on the sum of the squares of the current voltages of the three phases, the current voltage of the middle phase, and the DC voltage, determine the second duty cycle corresponding to the middle phase.

[0043] In a possible implementation, the controllable switch device is any one of an IGBT, a Mosfet, and a combination of an IGBT and a diode in reverse parallel.

[0044] 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.

[0045] The controller is configured to:

[0046] Based on the current voltages of the three phases in the three-phase alternating current, determine the maximum phase, the minimum phase, and the intermediate phase.

[0047] Based on the current voltage of the maximum phase, determine the first duty cycle corresponding to the maximum phase.

[0048] Based on the current voltage of the intermediate phase, determine the second duty cycle corresponding to the intermediate phase.

[0049] Based on the second duty cycle corresponding to the intermediate phase, determine the third duty cycle corresponding to the minimum phase, where the minimum phase is complementary to the intermediate phase.

[0050] Based on the current voltages of the three phases, the first duty cycle, the second duty cycle, and the third duty cycle, control multiple controllable switch devices in the current source type converter to conduct or disconnect.

[0051] In a possible implementation, the controller is configured to:

[0052] Within any switching period, when the controllable switch device corresponding to the intermediate phase is in the off state, control the controllable switch device on the upper arm or the controllable switch device on the lower arm corresponding to the minimum phase to be in the on state. When the controllable switch device corresponding to the intermediate phase is in the on state, control the controllable switch device on the upper arm and the controllable switch device on the lower arm corresponding to the minimum phase to be in the off state.

[0053] In a possible implementation, the controller is configured to:

[0054] Within any switching period, when the controllable switch devices corresponding to the maximum phase and the intermediate phase are both in the off state, control the controllable switch devices on the upper arm and the controllable switch devices on the lower arm corresponding to the minimum phase to be in the on state. When the controllable switch device corresponding to the maximum phase is in the on state and the controllable switch device corresponding to the intermediate phase is in the off state, control the controllable switch device on the upper arm or the controllable switch device on the lower arm corresponding to the minimum phase to be in the on state.

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

[0056] Based on the first duty cycle, control the controllable switch devices on the maximum-corresponding upper bridge arm and the controllable switch devices on the maximum-corresponding lower bridge arm to be both turned on or both turned off;

[0057] Based on the second duty cycle, control the controllable switch devices on the middle-corresponding upper bridge arm and the controllable switch devices on the middle-corresponding lower bridge arm to be both turned on or both turned off;

[0058] Based on the third duty cycle, control the controllable switch devices on the minimum-corresponding upper bridge arm and the controllable switch devices on the minimum-corresponding lower bridge arm to be both turned on or both turned off.

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

[0060] Based on the sum of squares of the current voltages of the three phases, the current voltage of the maximum phase, and the DC voltage, determine the first duty cycle corresponding to the maximum.

[0061] In a possible implementation, the controller is configured to:

[0062] Based on the sum of squares of the current voltages of the three phases, the current voltage of the middle phase, and the DC voltage, determine the second duty cycle corresponding to the middle.

[0063] In a possible implementation, the controllable switch device is any one of an IGBT, a Mosfet, and a combination of an IGBT and a diode in reverse parallel.

[0064] In a fourth aspect, 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.

[0065] In a fifth aspect, a computer-readable storage medium is provided, in which at least one instruction is stored, 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.

[0066] In a sixth aspect, a computer program product is provided, which 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.

[0067] 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 first duty cycle corresponding to the maximum phase is determined based on the current voltage of the maximum phase, the second duty cycle corresponding to the intermediate phase is determined based on the current voltage of the intermediate phase, and the minimum phase is complementary to the intermediate phase. In this way, within each switching cycle, the DC output voltage of the bridge arm will jump from zero to the line voltage between the minimum phase and the maximum phase, then jump from the line voltage between the minimum phase and the maximum phase to the line voltage between the intermediate phase and the maximum phase, then jump from the line voltage between the intermediate phase and the maximum phase to the line voltage between the minimum phase and the maximum phase, and then jump from the line voltage between the minimum phase and the maximum phase to zero.

[0068] Since in any sector of the 12 sectors, the line voltage between the minimum phase and the maximum phase is less than the line voltage between the intermediate phase and the maximum phase, therefore, by adopting the present disclosure, the jump amplitude of the DC output voltage of the bridge arm is reduced, thereby reducing the voltage stress and improving the EMI performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] 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.

[0070] Figure 1 is a topology diagram of a current source type converter provided by an embodiment of the present disclosure;

[0071] Figure 2 is a flowchart of a control method for a current source type converter provided by an embodiment of the present disclosure;

[0072] Figure 3 is a waveform diagram of a three-phase alternating current provided by an embodiment of the present disclosure;

[0073] Figure 4 is a driving timing diagram of a current source type converter in the related art;

[0074] Figure 5 is a schematic diagram of the change of the DC output voltage of the bridge arm in the related art;

[0075] Figure 6 is a driving timing diagram of a current source type converter provided by an embodiment of the present disclosure;

[0076] Figure 7 is a schematic diagram of the change of the DC output voltage of a bridge arm provided by an embodiment of the present disclosure;

[0077] Figure 8It is a schematic structural diagram of a control device for a current source type converter provided by an embodiment of the present disclosure;

[0078] Figure 9 It is a structural block diagram of a terminal provided by an embodiment of the present disclosure;

[0079] Figure 10 It is a structural block diagram of a server provided by an embodiment of the present disclosure. Detailed implementation manners

[0080] To make the objectives, technical solutions and advantages of the present disclosure clearer, the following will further describe in detail the embodiments of the present disclosure in conjunction with the accompanying drawings.

[0081] Refer to Figure 1 , Figure 1 is a topological schematic diagram of a current source type converter, where v a , v b , v c are the current voltages of three phases in three-phase alternating current, V dc is the direct current voltage, V PN is the direct current output voltage of the bridge arm. This current source type converter can convert three-phase alternating current into direct current, thereby forming a direct current bus.

[0082] 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:

[0083] 201. Based on the current voltages of three phases in three-phase alternating current, determine the maximum phase, minimum phase, and intermediate phase.

[0084] In implementation, the current voltages of three phases in three-phase alternating current can be periodically detected, that is, Figure 1 in v a , v b and v c , and the maximum phase, minimum phase, and intermediate phase are determined according to the magnitudes of the absolute values of the current voltages of these three phases.

[0085] Among the current voltages of three phases, the phase with the largest absolute value of the current voltage is the maximum phase, the phase with the smallest absolute value of the current voltage is the minimum phase, and the phase with the absolute value of the current voltage in the middle is the intermediate phase.

[0086] Refer to Figure 3 , in the embodiment of the present disclosure, the period of three-phase alternating current is divided into 12 sectors, that is, Figure 3 the sectors 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 in

[0087] In sector 1, vc > v a > 0 > v b , |v c | > |v c | > |v a |, then the maximum phase is v b , the intermediate phase is v c , the minimum phase is v a .

[0088] In sector 2, v a > v c > 0 > v b , |v b | > |v a | > |v c |, then the maximum phase is v b , the intermediate phase is v a , the minimum phase is v c .

[0089] In sector 3, v a > 0 > v c > v b , |v a | > |v b | > |v c |, then the maximum phase is v a , the intermediate phase is v b , the minimum phase is v c .

[0090] In sector 4, v a > 0 > v b > v c , |v a | > |v c | > |v b |, then the maximum phase is v a , the intermediate phase is v c , the minimum phase is v b .

[0091] In sector 5, v a > v b > 0 > v c , |v c | > |v a | > |v b |, then the maximum phase is v c , the intermediate phase is v a , the minimum phase is v b .

[0092] In sector 6, v b > v a > 0 > v c , |v c|>|v b |>|v a |, then the maximum phase is v c , the middle phase is v b , the minimum phase is v a 。

[0093] In sector 7, v b >0>v a >v c , |v b |>|v c |>|v a |, then the maximum phase is v b , the middle phase is v c , the minimum phase is v a 。

[0094] In sector 8, v b >0>v c >v a , |v c |>|v a |>|v c |, then the maximum phase is v b , the middle phase is v a , the minimum phase is v c 。

[0095] In sector 9, v b >v c >0>v a , |V a |>|v b |>|v c |, then the maximum phase is v a , the middle phase is v b , the minimum phase is v c 。

[0096] In sector 10, v c >v b >0>v a , |v a |>|v c |>|v b |, then the maximum phase is v a , the middle phase is v c , the minimum phase is v b 。

[0097] In sector 11, v c >0>v b >v a , |v c |>|v a |>|v b |, then the maximum phase is v c, the middle phase is v a , the minimum phase is v b .

[0098] In sector 12, v c > 0 > v a > v b , |v c | > |v b | > |v a |, then the maximum phase is v c , the middle phase is v b , the minimum phase is v a .

[0099] The characteristics of these 12 sectors are: in any sector, the current voltage of the maximum phase is opposite to the current voltage of the minimum phase, and the current voltage of the maximum phase is also opposite to the current voltage of the middle phase.

[0100] 202. Based on the current voltage of the maximum phase, determine the first duty cycle corresponding to the maximum phase.

[0101] In implementation, after determining the maximum phase, based on the current voltage of the maximum phase, calculate the first duty cycle corresponding to the maximum phase. The first duty cycle refers to the ratio of the conduction duration of the part of the controllable switching devices corresponding to the maximum phase to the total duration of the switching cycle. Among them, the part of the controllable switching devices corresponding to the maximum phase is the controllable switching device on the upper bridge arm corresponding to the maximum phase or the controllable switching device on the lower bridge arm corresponding to the maximum phase.

[0102] Since the first duty cycle is calculated based on the current voltage of the maximum phase, therefore, the maximum phase will be conducted at the middle time of the switching cycle, and the conduction duration of the maximum phase is the duration corresponding to the first duty cycle (i.e., the product of the first duty cycle and the total duration of the switching cycle).

[0103] The above-mentioned conduction of the maximum phase at the middle time of the switching cycle can also be understood as that in each switching cycle of the driving timing diagram, the driving signal of the maximum phase is symmetrically set with respect to the middle moment of the switching cycle.

[0104] 203. Based on the current voltage of the middle phase, determine the second duty cycle corresponding to the middle phase.

[0105] In implementation, after determining the middle phase, based on the current voltage of the middle phase, calculate the second duty cycle corresponding to the middle phase. The second duty cycle refers to the ratio of the conduction duration of the part of the controllable switching devices corresponding to the middle phase to the total duration of the switching cycle. Among them, the part of the controllable switching devices corresponding to the middle phase is the controllable switching device on the upper bridge arm corresponding to the middle phase or the controllable switching device on the lower bridge arm corresponding to the middle phase.

[0106] Since the second duty ratio is calculated based on the current voltage of the intermediate phase, the intermediate phase is turned on at the middle time of the switching cycle, and the conduction duration of the intermediate phase is the duration corresponding to the second duty ratio (i.e., the product of the second duty ratio and the total duration of the switching cycle).

[0107] The above-mentioned turning on of the intermediate phase at the middle time of the switching cycle can also be understood as that in each switching cycle of the driving timing diagram, the driving signal of the intermediate phase is symmetrically set with respect to the middle moment of the switching cycle.

[0108] 204. Determine the third duty ratio corresponding to the minimum phase based on the second duty ratio corresponding to the intermediate phase.

[0109] Among them, the minimum phase is complementary to the intermediate phase.

[0110] In implementation, after determining the second duty ratio corresponding to the intermediate phase, based on the principle that the minimum phase is complementary to the intermediate phase, the third duty ratio corresponding to the minimum phase is (1 - the second duty ratio).

[0111] The minimum phase is turned on at the initial time and the final time of the switching cycle, and the conduction duration of the minimum phase is the duration corresponding to the third duty ratio (i.e., the product of the third duty ratio and the total duration of the switching cycle), or it can also be the difference between the total duration of the switching cycle and the duration corresponding to the second duty ratio.

[0112] The above-mentioned turning on of the minimum phase at the initial time and the final time of the switching cycle can also be understood as that in each switching cycle of the driving timing diagram, the driving signal of the minimum phase is symmetrically located at both ends of the switching cycle, and the sum of the conduction durations of the minimum phase at both ends is the duration corresponding to the third duty ratio.

[0113] 205. Control the conduction or disconnection of multiple controllable switching devices in the current source type converter based on the current voltages of the three phases, the first duty ratio, the second duty ratio, and the third duty ratio.

[0114] In implementation, after determining the first duty ratio, the second duty ratio, and the third duty ratio, the conduction or disconnection of multiple controllable switching devices in the current source type converter can be controlled based on the current voltages of the three phases, the first duty ratio, the second duty ratio, and the third duty ratio.

[0115] In a possible implementation manner, the controllable switching 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 switching devices, and the embodiments of the present disclosure do not make specific limitations on this.

[0116] Next, the beneficial effects of the control method of the current source type converter provided by the present disclosure will be described in detail:

[0117] In the related art, usually, the duty cycle of the maximum phase and the duty cycle of the minimum phase are first calculated, and then the intermediate phase is complementary to the minimum phase. When the current source type converter is operating, the maximum phase and the minimum phase conduct in the middle time of a switching cycle, and the intermediate phase conducts at the beginning time and the end time of a switching cycle. Refer to Figure 4 , at the start (time 0) of a switching cycle ( Figure 4 0 - T5 or T5 - T10 in

[0118] ), the intermediate phase is in the conducting state. The maximum phase conducts at time T1. The intermediate phase disconnects and the minimum phase conducts at time T2. The minimum phase disconnects and the intermediate phase conducts at time T3. The maximum phase disconnects at time T4. The intermediate phase remains in the conducting state from time T4 to time T5 until entering the next switching cycle, and the above process is repeated. Among them, the duration corresponding to the duty cycle of the maximum phase is T1 - T4, the duration corresponding to the duty cycle of the minimum phase is T2 - T3, and the duration corresponding to the duty cycle of the intermediate phase is the sum of the duration of 0 - T2 and the duration of T3 - T5 (which is also equal to twice the duration of 0 - T2 and also equal to twice the duration of T3 - T5). Figure 5 In the above control process, refer to PN , since only the intermediate phase conducts during the 0 - T1 process, a loop cannot be formed in the arm, so the DC output voltage V PN of the arm is 0. The maximum phase conducts at time T1, and a loop is formed between the maximum phase and the intermediate phase. Therefore, at this time, the DC output voltage V PN of the arm jumps from 0 to "the line voltage between the intermediate phase and the maximum phase". The intermediate phase disconnects and the minimum phase conducts at time T2, and a loop is formed between the maximum phase and the minimum phase. Therefore, at this time, the DC output voltage V PN of the arm jumps from "the line voltage between the intermediate phase and the maximum phase" to "the line voltage between the minimum phase and the maximum phase". The minimum phase disconnects and the intermediate phase conducts at time T3, and a loop is formed between the maximum phase and the intermediate phase. Therefore, at this time, the DC output voltage V PN of the arm jumps from "the line voltage between the minimum phase and the maximum phase" to "the line voltage between the intermediate phase and the maximum phase". The maximum phase disconnects at time T4, and only the intermediate phase conducts, so a loop cannot be formed in the arm. Therefore, at this time, the DC output voltage V

[0119] jumps from "the line voltage between the intermediate phase and the maximum phase" to zero. PN And because the current voltage of the maximum phase and the current voltage of the minimum phase are in opposite directions in the same sector, and the current voltage of the maximum phase and the current voltage of the minimum phase are also in opposite directions, the line voltage formed between the intermediate phase and the maximum phase will be greater than the line voltage between the minimum phase and the maximum phase. Therefore, in the related art, the DC output voltage V Figure 5A relatively large jump between zero and the "line voltage formed between the intermediate phase and the maximum phase" as shown.

[0120] In the embodiments of the present disclosure, the first duty cycle corresponding to the maximum phase and the second duty cycle corresponding to the intermediate phase will be calculated first, and then the minimum phase and the intermediate phase are complementary. When the current source type converter operates, the maximum phase and the intermediate phase conduct in the middle time of a switching cycle, and the minimum phase conducts at the initial time and the end time of a switching cycle. Refer to Figure 6 , at the start (time 0) of a switching cycle ( Figure 6 0 - t5 or t5 - t10 in), the minimum phase is in the conducting state. At time t1, the maximum phase conducts. At time t2, the minimum phase disconnects and the intermediate phase conducts. At time t3, the intermediate phase disconnects and the minimum phase conducts. At time t4, the maximum phase disconnects. From time t4 to time t5, the minimum phase remains in the conducting state until entering the next switching cycle, and the above process is repeated. Among them, the duration corresponding to the first duty cycle of the maximum phase is t1 - t4, the duration corresponding to the second duty cycle of the intermediate phase is t2 - t3, and the duration corresponding to the third duty cycle of the minimum phase is the sum of the duration of 0 - t2 and the duration of t3 - t5 (also equal to twice the duration of 0 - t2, and also equal to twice the duration of t3 - t5).

[0121] In the above control process, refer to Figure 7 , during the 0 - t1 process, since only the minimum phase conducts and a loop cannot be formed in the arm, therefore, the DC output voltage V PN of the arm is 0; at time t1, the maximum phase conducts, and a loop is formed between the maximum phase and the minimum phase. Therefore, at this time, the DC output voltage V PN jumps from 0 to the "line voltage between the minimum phase and the maximum phase"; at time t2, the minimum phase disconnects and the intermediate phase conducts, and a loop is formed between the maximum phase and the intermediate phase. Therefore, at this time, the DC output voltage V PN jumps from the "line voltage between the minimum phase and the maximum phase" to the "line voltage between the intermediate phase and the maximum phase"; at time t3, the intermediate phase disconnects and the minimum phase conducts, and a loop is formed between the maximum phase and the minimum phase. Therefore, at this time, the DC output voltage V PN jumps from the "line voltage between the intermediate phase and the maximum phase" to the "line voltage between the minimum phase and the maximum phase"; at time t4, the maximum phase disconnects, and only the minimum phase conducts, and a loop cannot be formed in the arm. Therefore, at this time, the DC output voltage V PN jumps from the "line voltage between the minimum phase and the maximum phase" to zero.

[0122] It can be seen that by adopting the technical solution provided by the embodiments of the present disclosure, the DC output voltage V PNJust make a jump between zero and the line voltage between the minimum phase and the maximum phase, or make a jump between the line voltage between the minimum phase and the maximum phase and the line voltage between the intermediate phase and the maximum phase. The amplitudes of these two jumps are both smaller than the amplitude of the jump between zero and the line voltage between the intermediate phase and the maximum phase in the related art. Therefore, by adopting the technical solution provided by the embodiments of the present disclosure, the jump amplitude of the DC output voltage V of the bridge arm is reduced. PN Thus, the voltage stress is reduced, the current waveform quality of the good three-phase alternating current is ensured, the cost of the filter on the three-phase alternating current side is reduced, and the EMI performance is improved.

[0123] In the embodiments of the present disclosure, there are several methods for controlling the conduction or disconnection of multiple controllable switch devices in the current source type converter. Next, an introduction is made to them:

[0124] The first control method:

[0125] In any switching period, when the controllable switch device corresponding to the intermediate phase is in the off state, control the controllable switch device on the upper arm corresponding to the minimum phase or the controllable switch device on the lower arm corresponding to the minimum phase to be in the on state. When the controllable switch device corresponding to the intermediate phase is in the on state, control the controllable switch device on the upper arm corresponding to the minimum phase and the controllable switch device on the lower arm corresponding to the minimum phase to be in the off state.

[0126] In implementation, in any switching period, referring to Figure 6 , the conduction of some controllable switch devices corresponding to the minimum phase can be controlled first. The some controllable switch devices corresponding to the minimum phase refer to: when the current voltage of the minimum phase is greater than zero, control the controllable switch device on the upper arm corresponding to the minimum phase to be in the on state, and control the controllable switch device on the lower arm corresponding to the minimum phase to be in the off state; when the current voltage of the minimum phase is less than zero, control the controllable switch device on the lower arm corresponding to the minimum phase to be in the on state, and control the controllable switch device on the upper arm corresponding to the minimum phase to be in the off state.

[0127] At the moment t1, control some controllable switch devices corresponding to the maximum phase to be in the on state. First, the calculation method of the duration from 0 to t1 can be: first calculate the first difference between 1 and the first duty ratio, then multiply the first difference by the total duration of the switching period to obtain the first duration, and half of the first duration is the duration from 0 to t1. Second, the some controllable switch devices corresponding to the maximum phase refer to: when the current voltage of the maximum phase is greater than zero, control the controllable switch device on the upper arm corresponding to the maximum phase to be in the on state, and control the controllable switch device on the lower arm corresponding to the maximum phase to be in the off state; when the current voltage of the maximum phase is less than zero, control the controllable switch device on the lower arm corresponding to the maximum phase to be in the on state, and control the controllable switch device on the upper arm corresponding to the maximum phase to be in the off state.

[0128] At time t2, control the corresponding part of the controllable switching device in the on state to turn off, and control the corresponding part of the intermediate controllable switching device to turn on. First, the calculation method of the duration from 0 to t2 can be: first calculate the second difference between 1 and the second duty cycle, and then multiply the second difference by the total duration of the switching period to obtain the second duration, and half of the second duration is the duration from 0 to t2. Secondly, the corresponding part of the intermediate controllable switching device refers to: when the current voltage of the intermediate phase is greater than zero, control the controllable switching device on the upper arm corresponding to the intermediate to turn on, and control the controllable switching device on the lower arm corresponding to the intermediate to turn off; when the current voltage of the intermediate phase is less than zero, control the controllable switching device on the lower arm corresponding to the intermediate to turn on, and control the controllable switching device on the upper arm corresponding to the intermediate to turn off.

[0129] At time t3, control the corresponding part of the intermediate controllable switching device in the on state to turn off, and control the corresponding part of the minimum controllable switching device to turn on. The calculation method of the duration from t2 to t3 is: calculate the product of the second duty cycle and the total duration of the switching period, that is, obtain the duration from t2 to t3.

[0130] At time t4, control the corresponding part of the maximum controllable switching device in the on state to turn off. The calculation method of the duration from t1 to t2 is: calculate the product of the first duty cycle and the total duration of the switching period, that is, obtain the duration from t1 to t2.

[0131] During the time period from t4 to t5, only the corresponding part of the minimum controllable switching device is in the on state.

[0132] The second control method:

[0133] In any switching period, when both the corresponding maximum controllable switching device and the corresponding intermediate controllable switching device are in the off state, control both the controllable switching device on the upper arm corresponding to the minimum and the controllable switching device on the lower arm corresponding to the minimum to be in the on state. When the corresponding maximum controllable switching device is in the on state and the corresponding intermediate controllable switching device is in the off state, control either the controllable switching device on the upper arm corresponding to the minimum or the controllable switching device on the lower arm corresponding to the minimum to be in the on state.

[0134] In implementation, in any switching period, refer to Figure 6 , you can first control both the controllable switching device on the upper arm corresponding to the minimum and the controllable switching device on the lower arm corresponding to the minimum to turn on. At this time, since only the corresponding minimum controllable switching device in the three-phase corresponding bridge arm parts is turned on, therefore, the bridge arm DC output voltage V PNThe voltages at points P and N at both ends are clamped to the current voltage of the minimum phase, so that the voltages at points P and N do not jump to exceed the current voltage of the minimum phase, realizing active clamping and thus reducing the voltage stress.

[0135] Moreover, when all the controllable switch devices corresponding to the minimum phase are in the on state, since the voltage drop across the series circuit of all the controllable switch devices of the minimum phase is greater than that of D dc the voltage drop, therefore, the current will flow through D dc instead of flowing through the series circuit where all the controllable switch devices of the minimum phase are located. Therefore, controlling all the controllable switch devices of the minimum phase to conduct will not have any impact on the operation of the current source type converter, ensuring reliable operation even when the input voltage of the three-phase alternating current (i.e., the current voltage of the three phases) is relatively high, and ensuring a wide range of input voltage operating ranges.

[0136] At time t1, control some of the controllable switch devices corresponding to the maximum phase to conduct and control some of the controllable switch devices corresponding to the minimum phase to turn off. First, the calculation method for the duration of 0 - t1 can be: first calculate the first difference between 1 and the first duty cycle, then multiply the first difference by the total duration of the switching period to obtain the first duration, and half of the first duration is the duration of 0 - t1. Second, some of the controllable switch devices corresponding to the maximum phase refer to: when the current voltage of the maximum phase is greater than zero, control the controllable switch device on the upper bridge arm corresponding to the maximum phase to conduct and control the controllable switch device on the lower bridge arm corresponding to the maximum phase to turn off; when the current voltage of the maximum phase is less than zero, control the controllable switch device on the lower bridge arm corresponding to the maximum phase to conduct and control the controllable switch device on the upper bridge arm corresponding to the maximum phase to turn off. Then, controlling some of the controllable switch devices corresponding to the minimum phase to turn off means: when the current voltage of the minimum phase is greater than zero, control the controllable switch device on the lower bridge arm corresponding to the minimum phase to turn off, and the controllable switch device on the upper bridge arm corresponding to the minimum phase remains in the on state; when the current voltage of the minimum phase is less than zero, control the controllable switch device on the upper bridge arm corresponding to the minimum phase to turn off, and the controllable switch device on the lower bridge arm corresponding to the minimum phase remains in the on state.

[0137] At time t2, control the corresponding part of the controllable switch device in the on state to turn off, and control the corresponding part of the controllable switch device in the middle to turn on. First, the calculation method of the duration from 0 to t2 can be: first calculate the second difference between 1 and the second duty cycle, and then multiply the second difference by the total duration of the switching period to obtain the second duration, and half of the second duration is the duration from 0 to t2. Second, the corresponding part of the controllable switch device in the middle refers to: when the current voltage of the middle phase is greater than zero, control the controllable switch device on the upper arm corresponding to the middle to turn on, and control the controllable switch device on the lower arm corresponding to the middle to turn off; when the current voltage of the middle phase is less than zero, control the controllable switch device on the lower arm corresponding to the middle to turn on, and control the controllable switch device on the upper arm corresponding to the middle to turn off.

[0138] At time t3, control the corresponding part of the controllable switch device in the on state in the middle to turn off, and control the corresponding part of the controllable switch device with the minimum value to turn on. The calculation method of the duration from t2 to t3 is: calculate the product of the second duty cycle and the total duration of the switching period, that is, obtain the duration from t2 to t3.

[0139] At time t4, control the corresponding part of the controllable switch device in the on state with the maximum value to turn off, and control the corresponding part of the controllable switch device in the off state with the minimum value to turn on. The calculation method of the duration from t1 to t2 is: calculate the product of the first duty cycle and the total duration of the switching period, that is, obtain the duration from t1 to t2.

[0140] During the time period from t4 to t5, the controllable switch devices on the upper arm corresponding to the minimum value and the controllable switch devices on the lower arm corresponding to the minimum value are both in the on state, so that the voltages at point P and point N will not jump to exceed the current voltage of the minimum phase, realizing active clamping, thereby reducing the voltage stress.

[0141] The third control method:

[0142] Within any switching period, based on the first duty cycle, control both the controllable switch device on the upper arm corresponding to the maximum value and the controllable switch device on the lower arm corresponding to the maximum value to be turned on or turned off; based on the second duty cycle, control both the controllable switch device on the upper arm corresponding to the middle value and the controllable switch device on the lower arm corresponding to the middle value to be turned on or turned off; based on the third duty cycle, control both the controllable switch device on the upper arm corresponding to the minimum value and the controllable switch device on the lower arm corresponding to the minimum value to be turned on or turned off.

[0143] In implementation, refer to Figure 6 , taking the switching period from 0 to t5 as an example, based on the first duty cycle and the total duration of the switching period, the conduction period of the maximum phase in the switching period can be determined (that is Figure 6If it is within t1 - t4 in [ ], then at time t1, it is possible to control both the controllable switching device on the upper bridge arm corresponding to the maximum and the controllable switching device on the lower bridge arm corresponding to the maximum to be turned on, and at time t4, it is possible to control both the controllable switching device on the upper bridge arm corresponding to the maximum and the controllable switching device on the lower bridge arm corresponding to the maximum to be turned off.

[0144] Based on the second duty cycle and the total duration of the switching period, the conduction period of the intermediate phase in the switching period can be determined (i.e., Figure 6 If it is within t2 - t3 in [ ], then at time t2, it is possible to control both the controllable switching device on the upper bridge arm corresponding to the intermediate phase and the controllable switching device on the lower bridge arm corresponding to the intermediate phase to be turned on, and at time t3, it is possible to control both the controllable switching device on the upper bridge arm corresponding to the intermediate phase and the controllable switching device on the lower bridge arm corresponding to the intermediate phase to be turned off.

[0145] Based on the third duty cycle and the total duration of the switching period, the conduction period of the minimum phase in the switching period can be determined (i.e., Figure 6 If it is within 0 - t2 and t3 - t5 in [ ], then at time t3, it is possible to control both the controllable switching device on the upper bridge arm corresponding to the minimum and the controllable switching device on the lower bridge arm corresponding to the minimum to be turned on, and at time t7 in the next switching period, it is possible to control both the controllable switching device on the upper bridge arm corresponding to the minimum and the controllable switching device on the lower bridge arm corresponding to the minimum to be turned off.

[0146] With such a setting, it is possible to achieve the beneficial effects of "when both the controllable switching device corresponding to the maximum and the controllable switching device corresponding to the intermediate are in the off state, controlling both the controllable switching device on the upper bridge arm corresponding to the minimum and the controllable switching device on the lower bridge arm corresponding to the minimum to be in the on state, and when the controllable switching device corresponding to the maximum is in the on state and the controllable switching device corresponding to the intermediate is in the off state, controlling either the controllable switching device on the upper bridge arm corresponding to the minimum or the controllable switching device on the lower bridge arm corresponding to the minimum to be in the on state" in the second control method, that is, reducing the voltage stress, ensuring a wide range of input voltage operating range, and also reducing the complexity of the control method.

[0147] The above - mentioned several control methods are only listed. The control method in the embodiments of the present disclosure can also be other reasonable methods, and the embodiments of the present disclosure do not make specific limitations in this regard.

[0148] In the embodiments of the present disclosure, the method for determining the first duty cycle corresponding to the maximum can be as follows:

[0149] Based on the sum of the squares of the current voltages of the three phases, the current voltage of the maximum phase, and the DC voltage, determine the first duty cycle corresponding to the maximum.

[0150] In a possible implementation, the maximum corresponding first duty cycle can be determined based on the following formula (1):

[0151]

[0152] where d Max is the first duty cycle, V dc is the DC voltage, and v a , v b , v c are the current voltages of the three-phase alternating current respectively.

[0153] In the embodiments of the present disclosure, the method for determining the intermediate corresponding second duty cycle can be as follows:

[0154] Based on the sum of the squares of the current voltages of the three phases, the current voltage of the intermediate phase, and the DC voltage, determine the intermediate corresponding second duty cycle.

[0155] In a possible implementation, the intermediate corresponding second duty cycle can be determined based on the following formula (2):

[0156]

[0157] where d Mid is the second duty cycle, V dc is the DC voltage, and v a , v b , v c are the current voltages of the three-phase alternating current respectively.

[0158] Next, referring to Table 1, a summary introduction to the calculation methods of the duty cycles corresponding to the three phases in each sector is given:

[0159] Table 1

[0160]

[0161] In the embodiments of the present disclosure, the calculation method of the duty cycle corresponding to the three phases can also be other reasonable methods, and the embodiments of the present disclosure do not make specific limitations on this.

[0162] All the above optional technical solutions can be combined arbitrarily to form the optional embodiments of the present disclosure, which will not be elaborated one by one here.

[0163] In the solutions mentioned in the embodiments of the present disclosure, the maximum corresponding first duty cycle is determined based on the current voltage of the maximum phase, the intermediate corresponding second duty cycle is determined based on the current voltage of the intermediate phase, and the minimum phase is complementary to the intermediate phase. In this way, within each switching cycle, the DC output voltage V PNIt will jump from zero to the line voltage between the minimum phase and the maximum phase, then jump from the line voltage between the minimum phase and the maximum phase to the line voltage between the middle phase and the maximum phase, then jump from the line voltage between the middle phase and the maximum phase to the line voltage between the minimum phase and the maximum phase, and then jump from the line voltage between the minimum phase and the maximum phase to zero.

[0164] And since in any sector among the 12 sectors, the line voltage between the minimum phase and the maximum phase is less than the line voltage between the middle phase and the maximum phase, therefore, the jump amplitude of the DC output voltage V of the bridge arm is reduced, PN thus reducing the voltage stress, ensuring good current waveform quality of the three-phase alternating current, reducing the cost of the filter on the three-phase alternating current side, and improving the EMI performance.

[0165] The embodiment of the present disclosure provides a control device for a current source type converter, and this device can be the computer device in the above embodiment, such as Figure 8 as shown, the device includes:

[0166] A first determination module 810, configured to determine the maximum phase, the minimum phase, and the middle phase based on the current voltages of the three phases in the three-phase alternating current;

[0167] A second determination module 820, configured to determine the first duty ratio corresponding to the maximum phase based on the current voltage of the maximum phase;

[0168] A third determination module 830, configured to determine the second duty ratio corresponding to the middle phase based on the current voltage of the middle phase;

[0169] A fourth determination module 840, configured to determine the third duty ratio corresponding to the minimum phase based on the second duty ratio corresponding to the middle phase, where the minimum phase and the middle phase are complementary;

[0170] A control module 850, configured to control the conduction or disconnection of multiple controllable switching devices in the current source type converter based on the current voltages of the three phases, the first duty ratio, the second duty ratio, and the third duty ratio.

[0171] In a possible implementation manner, the control module 850 is configured to:

[0172] Within any switching period, when the controllable switching device corresponding to the middle phase is in the off state, control the controllable switching device on the upper bridge arm corresponding to the minimum phase or the controllable switching device on the lower bridge arm corresponding to the minimum phase to be in the on state, and when the controllable switching device corresponding to the middle phase is in the on state, control the controllable switching device on the upper bridge arm corresponding to the minimum phase and the controllable switching device on the lower bridge arm corresponding to the minimum phase to be in the off state.

[0173] In a possible implementation, the control module 850 is further configured to:

[0174] In any switching period, when both the controllable switching device corresponding to the maximum and the controllable switching device corresponding to the middle are in the off state, control both the controllable switching device on the upper bridge arm corresponding to the minimum and the controllable switching device on the lower bridge arm corresponding to the minimum to be in the on state; when the controllable switching device corresponding to the maximum is in the on state and the controllable switching device corresponding to the middle is in the off state, control either the controllable switching device on the upper bridge arm corresponding to the minimum or the controllable switching device on the lower bridge arm corresponding to the minimum to be in the on state.

[0175] In a possible implementation, the control module 850 is configured to:

[0176] Based on the first duty cycle, control both the controllable switching device on the upper bridge arm corresponding to the maximum and the controllable switching device on the lower bridge arm corresponding to the maximum to be either both on or both off;

[0177] Based on the second duty cycle, control both the controllable switching device on the upper bridge arm corresponding to the middle and the controllable switching device on the lower bridge arm corresponding to the middle to be either both on or both off;

[0178] Based on the third duty cycle, control both the controllable switching device on the upper bridge arm corresponding to the minimum and the controllable switching device on the lower bridge arm corresponding to the minimum to be either both on or both off.

[0179] In a possible implementation, the second determination module 820 is configured to:

[0180] Based on the sum of the squares of the current voltages of the three phases, the current voltage of the maximum phase, and the DC voltage, determine the first duty cycle corresponding to the maximum.

[0181] In a possible implementation, the third determination module 830 is configured to:

[0182] Based on the sum of the squares of the current voltages of the three phases, the current voltage of the middle phase, and the DC voltage, determine the second duty cycle corresponding to the middle.

[0183] In a possible implementation, the controllable switching device is any one of an IGBT, a Mosfet, and a combination of an IGBT and a diode in reverse parallel.

[0184] 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 and will not be elaborated here.

[0185] 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.

[0186] The controller is configured to:

[0187] Based on the current voltages of the three phases in the three-phase alternating current, determine the maximum phase, the minimum phase, and the intermediate phase;

[0188] Based on the current voltage of the maximum phase, determine the first duty cycle corresponding to the maximum phase;

[0189] Based on the current voltage of the intermediate phase, determine the second duty cycle corresponding to the intermediate phase;

[0190] Based on the second duty cycle corresponding to the intermediate phase, determine the third duty cycle corresponding to the minimum phase, where the minimum phase and the intermediate phase are complementary;

[0191] Based on the current voltages of the three phases, the first duty cycle, the second duty cycle, and the third duty cycle, control multiple controllable switch devices in the current source type converter to turn on or off.

[0192] In a possible implementation, the controller is configured to:

[0193] Within any switching period, when the controllable switch device corresponding to the intermediate phase is in the off state, control the controllable switch device on the upper arm or the controllable switch device on the lower arm corresponding to the minimum phase to be in the on state. When the controllable switch device corresponding to the intermediate phase is in the on state, control the controllable switch device on the upper arm and the controllable switch device on the lower arm corresponding to the minimum phase to be in the off state.

[0194] In a possible implementation, the controller is configured to:

[0195] During any switching period, when both the controllable switching device corresponding to the maximum and the controllable switching device corresponding to the middle are in the off state, control both the controllable switching device on the upper arm corresponding to the minimum and the controllable switching device on the lower arm corresponding to the minimum to be in the on state. When the controllable switching device corresponding to the maximum is in the on state and the controllable switching device corresponding to the middle is in the off state, control either the controllable switching device on the upper arm corresponding to the minimum or the controllable switching device on the lower arm corresponding to the minimum to be in the on state.

[0196] In a possible implementation, the controller is configured to:

[0197] Based on the first duty cycle, control both the controllable switching device on the upper arm corresponding to the maximum and the controllable switching device on the lower arm corresponding to the maximum to be either both on or both off;

[0198] Based on the second duty cycle, control both the controllable switching device on the upper arm corresponding to the middle and the controllable switching device on the lower arm corresponding to the middle to be either both on or both off;

[0199] Based on the third duty cycle, control both the controllable switching device on the upper arm corresponding to the minimum and the controllable switching device on the lower arm corresponding to the minimum to be either both on or both off.

[0200] In a possible implementation, the controller is configured to:

[0201] Based on the sum of the squares of the current voltages of the three phases, the current voltage of the maximum phase, and the DC voltage, determine the first duty cycle corresponding to the maximum.

[0202] In a possible implementation, the controller is configured to:

[0203] Based on the sum of the squares of the current voltages of the three phases, the current voltage of the middle phase, and the DC voltage, determine the second duty cycle corresponding to the middle.

[0204] In a possible implementation, the controllable switching device is any one of an IGBT, a Mosfet, and a combination of an IGBT and a diode in reverse parallel.

[0205] Figure 9The structural block diagram of a terminal 900 provided by an exemplary embodiment of the present disclosure is shown. The terminal may be the computer device in the above embodiment. The terminal 900 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 900 may also be referred to by other names such as user equipment, portable terminal, laptop terminal, desktop terminal, etc.

[0206] Generally, the terminal 900 includes: a processor 901 and a memory 902.

[0207] The processor 901 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 901 may be implemented in at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), PLA (Programmable Logic Array). The processor 901 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 the CPU (Central Processing Unit); the co-processor is a low-power processor for processing data in the standby state. In some embodiments, the processor 901 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 901 may further include an AI (Artificial Intelligence) processor, and the AI processor is used to process computational operations related to machine learning.

[0208] The memory 902 may include one or more computer-readable storage media, and the computer-readable storage media may be non-transitory. The memory 902 may also include high-speed random access memory, as well as non-volatile memory, such as one or more disk storage devices, flash storage devices. In some embodiments, the non-transitory computer-readable storage media in the memory 902 is used to store at least one instruction, and the at least one instruction is used to be executed by the processor 901 to implement the control method of the current source type converter provided in the method embodiment of the present disclosure.

[0209] In some embodiments, the terminal 900 may further optionally include: a peripheral device interface 903 and at least one peripheral device. The processor 901, the memory 902, and the peripheral device interface 903 may be connected via a bus or signal lines. Each peripheral device may be connected to the peripheral device interface 903 via a bus, signal lines, or a circuit board. Specifically, the peripheral device includes at least one of: a radio frequency circuit 904, a display screen 905, a camera 906, an audio circuit 907, a positioning component 908, and a power supply 909.

[0210] The peripheral device interface 903 can be used to connect at least one I / O (input / output) related peripheral device to the processor 901 and the memory 902. In some embodiments, the processor 901, the memory 902, and the peripheral device interface 903 are integrated on the same chip or circuit board; in some other embodiments, any one or two of the processor 901, the memory 902, and the peripheral device interface 903 can be implemented on separate chips or circuit boards, and this embodiment does not limit this.

[0211] The radio frequency circuit 904 is used to receive and transmit RF (radio frequency) signals, also known as electromagnetic signals. The radio frequency circuit 904 communicates with a communication network and other communication devices through electromagnetic signals. The radio frequency circuit 904 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 904 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 904 can 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 904 may further include a circuit related to NFC (near field communication), and this disclosure does not limit this.

[0212] The display screen 905 is used to display the UI (user interface). The UI may include graphics, text, icons, videos, and any combination thereof. When the display screen 905 is a touch display screen, the display screen 905 also has the ability to collect touch signals on or above the surface of the display screen 905. The touch signals can be input to the processor 901 as control signals for processing. At this time, the display screen 905 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 905, which is provided on the front panel of the terminal 900; in other embodiments, there may be at least two display screens 905, which are respectively provided on different surfaces of the terminal 900 or are in a folded design; in still other embodiments, the display screen 905 may be a flexible display screen, which is provided on the curved surface or the folding surface of the terminal 900. Even further, the display screen 905 can also be set to an irregular non-rectangular shape, that is, a special-shaped screen. The display screen 905 can be prepared using materials such as LCD (liquid crystal display) and OLED (organic light-emitting diode).

[0213] The camera module 906 is used to collect images or videos. Optionally, the camera module 906 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 906 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.

[0214] The audio circuit 907 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 901 for processing, or input to the radio frequency circuit 904 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 900. The microphone may also be an array microphone or an omnidirectional collection microphone. The speaker is used to convert the electrical signal from the processor 901 or the radio frequency circuit 904 into sound waves. The speaker may be a traditional thin film speaker or a piezoelectric ceramic speaker. When the speaker is a piezoelectric ceramic speaker, it can not only convert the electrical signal into sound waves audible to humans, but also convert the electrical signal into sound waves inaudible to humans for uses such as ranging. In some embodiments, the audio circuit 907 may further include a headphone jack.

[0215] The positioning component 908 is used to locate the current geographical location of the terminal 900 to implement navigation or LBS (location based service). The positioning component 908 may be a positioning component based on GPS (global positioning system), Beidou system, GLONASS system or Galileo system.

[0216] The power supply 909 is used to supply power to each component in the terminal 900. The power supply 909 may be alternating current, direct current, a disposable battery or a rechargeable battery. When the power supply 909 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.

[0217] In some embodiments, the terminal 900 further includes one or more sensors 910. The one or more sensors 910 include but are not limited to: an acceleration sensor 911, a gyroscope sensor 912, a pressure sensor 913, a fingerprint sensor 914, an optical sensor 915 and a proximity sensor 916.

[0218] The acceleration sensor 911 can detect the magnitude of acceleration on the three coordinate axes of the coordinate system established with the terminal 900. For example, the acceleration sensor 911 can be used to detect the components of the gravitational acceleration on the three coordinate axes. The processor 901 can control the display screen 905 to display the user interface in a landscape view or a portrait view according to the gravitational acceleration signal collected by the acceleration sensor 911. The acceleration sensor 911 can also be used for collecting game or user's motion data.

[0219] The gyroscope sensor 912 can detect the body orientation and rotation angle of the terminal 900. The gyroscope sensor 912 can cooperate with the acceleration sensor 911 to collect the user's 3D actions on the terminal 900. Based on the data collected by the gyroscope sensor 912, the processor 901 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.

[0220] The pressure sensor 913 can be disposed on the side frame of the terminal 900 and / or the lower layer of the display screen 905. When the pressure sensor 913 is disposed on the side frame of the terminal 900, it can detect the user's holding signal on the terminal 900, and the processor 901 can perform left / right hand recognition or quick operation based on the holding signal collected by the pressure sensor 913. When the pressure sensor 913 is disposed on the lower layer of the display screen 905, the processor 901 can control the operable controls on the UI interface according to the user's pressure operation on the display screen 905. The operable controls include at least one of button controls, scroll bar controls, icon controls, and menu controls.

[0221] The fingerprint sensor 914 is used to collect the user's fingerprint. The processor 901 can identify the user's identity based on the fingerprint collected by the fingerprint sensor 914, or the fingerprint sensor 914 can identify the user's identity based on the collected fingerprint. When the identified user identity is a trusted identity, the processor 901 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 914 can be disposed on the front, back, or side of the terminal 900. When there are physical buttons or manufacturer logos on the terminal 900, the fingerprint sensor 914 can be integrated with the physical buttons or manufacturer logos.

[0222] The optical sensor 915 is used to collect the ambient light intensity. In one embodiment, the processor 901 can control the display brightness of the display screen 905 according to the ambient light intensity collected by the optical sensor 915. Specifically, when the ambient light intensity is high, the display brightness of the display screen 905 is increased; when the ambient light intensity is low, the display brightness of the display screen 905 is decreased. In another embodiment, the processor 901 can also dynamically adjust the shooting parameters of the camera module 906 according to the ambient light intensity collected by the optical sensor 915.

[0223] The proximity sensor 916, also known as a distance sensor, is usually disposed on the front panel of the terminal 900. The proximity sensor 916 is used to collect the distance between the user and the front of the terminal 900. In one embodiment, when the proximity sensor 916 detects that the distance between the user and the front of the terminal 900 is gradually decreasing, the processor 901 controls the display screen 905 to switch from the lit state to the off state; when the proximity sensor 916 detects that the distance between the user and the front of the terminal 900 is gradually increasing, the processor 901 controls the display screen 905 to switch from the off state to the lit state.

[0224] Those skilled in the art can understand that Figure 9 the structure shown in does not constitute a limitation on the terminal 900, and may include more or fewer components than shown in the figure, or combine some components, or adopt a different component arrangement.

[0225] Figure 10 is a schematic structural diagram of a server provided by an embodiment of the present disclosure. The server 1000 may vary greatly due to different configurations or performances, and may include one or more processors (central processing units, CPUs) 1001 and one or more memories 1002. Among them, at least one instruction is stored in the memory 1002, and the at least one instruction is loaded and executed by the processor 1001 to implement the methods provided by the above 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.

[0226] In an exemplary embodiment, a computer-readable storage medium is also provided. For example, a memory including instructions, and the above instructions can be executed by a processor in the terminal to complete the control method of the current-source type converter in the above embodiments. 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.

[0227] 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 disk, etc.

[0228] 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 the relevant laws, regulations, and standards of relevant countries and regions. For example, the "current three-phase voltage" involved in this disclosure is obtained under full authorization.

[0229] 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 principles 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: Determining a maximum phase, a minimum phase, and an intermediate phase based on the current voltages of the three phases in the three-phase alternating current; Determining a first duty ratio corresponding to the maximum phase based on the current voltage of the maximum phase; Determining a second duty ratio corresponding to the intermediate phase based on the current voltage of the intermediate phase; Determining a third duty ratio corresponding to the minimum phase based on the second duty ratio corresponding to the intermediate phase, where the minimum phase is complementary to the intermediate phase; Controlling multiple controllable switch devices in the current source type converter to conduct or disconnect based on the first duty ratio, the second duty ratio, and the third duty ratio.

2. The method according to claim 1, wherein The controlling multiple controllable switch devices in the current source type converter to conduct or disconnect based on the first duty ratio, the second duty ratio, and the third duty ratio includes: During any switching period, when the controllable switch device corresponding to the intermediate phase is in the off state, controlling the controllable switch device on the upper arm or the controllable switch device on the lower arm corresponding to the minimum phase to be in the on state, and when the controllable switch device corresponding to the intermediate phase is in the on state, controlling both the controllable switch device on the upper arm and the controllable switch device on the lower arm corresponding to the minimum phase to be in the off state.

3. The method according to claim 1, characterized in that, The controlling multiple controllable switch devices in the current source type converter to conduct or disconnect based on the first duty ratio, the second duty ratio, and the third duty ratio includes: During any switching period, when both the controllable switch device corresponding to the maximum phase and the controllable switch device corresponding to the intermediate phase are in the off state, controlling both the controllable switch device on the upper arm and the controllable switch device on the lower arm corresponding to the minimum phase to be in the on state, and when the controllable switch device corresponding to the maximum phase is in the on state and the controllable switch device corresponding to the intermediate phase is in the off state, controlling the controllable switch device on the upper arm or the controllable switch device on the lower arm corresponding to the minimum phase to be in the on state.

4. The method according to claim 1, wherein The controlling multiple controllable switch devices in the current source type converter to conduct or disconnect based on the first duty ratio, the second duty ratio, and the third duty ratio includes: During any switching period, controlling both the controllable switch device on the upper arm and the controllable switch device on the lower arm corresponding to the maximum phase to conduct or disconnect based on the first duty ratio; Controlling both the controllable switch device on the upper arm and the controllable switch device on the lower arm corresponding to the intermediate phase to conduct or disconnect based on the second duty ratio; Controlling both the controllable switch device on the upper arm and the controllable switch device on the lower arm corresponding to the minimum phase to conduct or disconnect based on the third duty ratio.

5. The method according to claim 1, wherein The determining the first duty ratio corresponding to the maximum phase based on the current voltage of the maximum phase includes: Determining the first duty ratio corresponding to the maximum phase based on the sum of the squares of the current voltages of the three phases, the current voltage of the maximum phase, and the DC voltage.

6. The method according to claim 1, wherein Determining the second duty ratio corresponding to the intermediate phase based on the current voltage of the intermediate phase includes: Determining the second duty ratio corresponding to the intermediate phase based on the sum of the squares of the current voltages of the three phases, the current voltage of the intermediate phase, and the DC voltage.

7. A control device for a current source type converter, characterized in that, The device includes: A first determination module, configured to determine a maximum phase, a minimum phase, and an intermediate phase based on the current voltages of the three phases in the three-phase alternating current; A second determination module, configured to determine the first duty ratio corresponding to the maximum phase based on the current voltage of the maximum phase; A third determination module, configured to determine the second duty ratio corresponding to the intermediate phase based on the current voltage of the intermediate phase; A fourth determination module, configured to determine the third duty ratio corresponding to the minimum phase based on the second duty ratio corresponding to the intermediate phase, where the minimum phase is complementary to the intermediate phase; A control module, configured to control multiple controllable switch devices in the current source type converter to conduct or disconnect based on the current voltages of the three phases, the first duty ratio, the second duty ratio, and the third duty ratio.

8. A control circuit for a current source type converter, characterized in that, The control circuit includes a current source type converter and a controller; The controller is configured to: Determine a maximum phase, a minimum phase, and an intermediate phase based on the current voltages of the three phases in the three-phase alternating current; Determine the first duty ratio corresponding to the maximum phase based on the current voltage of the maximum phase; Determine the second duty ratio corresponding to the intermediate phase based on the current voltage of the intermediate phase; Determine the third duty ratio corresponding to the minimum phase based on the second duty ratio corresponding to the intermediate phase, where the minimum phase is complementary to the intermediate phase; Control multiple controllable switch devices in the current source type converter to conduct or disconnect based on the current voltages of the three phases, the first duty ratio, the second duty ratio, and the third duty ratio.

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

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

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