Methods, apparatus, actuation devices, and computer readable media for operating a conductive assembly

Abstract

Embodiments of the present disclosure relate to a method, an apparatus, a starting device and a computer readable medium for operating a turn-on assembly. The turn-on assembly is coupled between an alternating current power source and an inductive load, and includes a first switch device and a second switch device connected in reverse series, the first switch device including a first body diode connected in reverse parallel with the first switch device, and the second switch device including a second body diode connected in reverse parallel with the second switch device. The method includes: in a first period, turning on the turn-on assembly at a first turn-on angle; and in a second period, turning on the turn-on assembly at a second turn-on angle greater than the first turn-on angle, wherein in the first period and the second period, based on a current flowing through the turn-on assembly, determining a turn-off timing of the first switch device or the second switch device having the first body diode or the second body diode connected in reverse parallel with the same current direction. The method presented herein can reduce power loss of a soft start circuit.

Description

Technical Field

[0001] The embodiments of the present invention generally relate to a method, apparatus, starting device, and computer-readable medium for operating a conducting component, and more specifically, to a method, apparatus, starting device, and computer-readable medium for operating a soft-start circuit. Background Technology

[0002] Existing soft-start methods mostly employ a gradual increase in the conduction angle of the conducting device over multiple cycles. However, existing soft-start methods result in significant power loss during startup and also reduce the lifespan of components. Summary of the Invention

[0003] Embodiments of this disclosure provide a method, apparatus, initiation device, and computer-readable medium for operating a conducting component, which can reduce losses generated during the initiation process, thereby at least partially solving the above-mentioned and other potential problems existing in the prior art.

[0004] The first aspect of this disclosure relates to a method of operating a conducting component. The conducting component is coupled between an AC power source and an inductive load, and includes a first switching device and a second switching device connected in reverse series. The first switching device includes a first body diode connected in antiparallel to the first switching device, and the second switching device includes a second body diode connected in antiparallel to the second switching device. The method includes: in a first cycle, turning on the conducting component at a first conduction angle; and in a second cycle, turning on the conducting component at a second conduction angle greater than the first conduction angle, wherein, in the first and second cycles, based on the current flowing through the conducting component, a turn-off timing is determined for the first or second switching device connected in antiparallel to the first or second body diode, whose conduction direction is the same as the current direction.

[0005] Through the above embodiments, the first switching device and the second switching device are at least partially in a state of simultaneous conduction during the startup process, thereby reducing power loss compared to the existing soft-start method.

[0006] According to one embodiment, determining the turn-off timing based on current includes: detecting the magnitude of the current; and, in response to the current being less than a threshold, providing a turn-off signal to a first or second switching device connected in reverse parallel to a first body diode or a second body diode whose conduction direction is the same as the current direction. Through the above embodiment, the magnitude of the current flowing through the body diode can be reduced, thereby reducing the power loss of the body diode.

[0007] According to one embodiment, the method further includes activating the conductive component at at least one third conduction angle in at least one third cycle, wherein the conduction angle used in the later cycle of the first, second, and third cycles is greater than the conduction angle used in the earlier cycle. Through the above embodiment, soft start can be achieved.

[0008] According to one embodiment, the method further includes providing a turn-off signal to a first switching device or a second switching device in response to a current equal to zero. Through the above embodiments, natural zero-crossing turn-off of the conducting component can be achieved, increasing the service life of the conducting component.

[0009] According to one embodiment, the method further includes determining the increase in the conduction angle per cycle based on the voltage boost slope of the inductive load and a preset boost curve. Through the above embodiment, soft-start can be achieved at a predetermined rate.

[0010] According to one embodiment, the threshold is determined based on the accuracy of current detection. Through the above embodiments, power loss in the conducting components can be minimized.

[0011] According to one embodiment, the shutdown timing includes the zero-crossing point of the voltage across the conducting component. With this embodiment, soft-start can be achieved simply by detecting the voltage across the conducting component.

[0012] A second aspect of this disclosure relates to an apparatus for operating a conducting component. The conducting component is coupled between an AC power source and an inductive load, and includes a first switching device and a second switching device connected in reverse series. The first switching device includes a first body diode connected in reverse parallel with the first switching device, and the second switching device includes a second body diode connected in reverse parallel with the second switching device. The apparatus includes: a current sampling device for sampling current in the conducting component; and a controller communicatively connected to the current sampling device and configured to perform the method according to any one of the foregoing embodiments.

[0013] A third aspect of this disclosure relates to a starting device, including the device described in the foregoing embodiments.

[0014] A fourth aspect of this disclosure relates to a computer-readable medium having computer-executable instructions stored thereon, which, when run on a processor, perform the method according to any one of the foregoing embodiments. Attached Figure Description

[0015] The above and other objects, features, and advantages of embodiments of the present disclosure will become more readily understood from the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the present disclosure will be described by way of example and non-limitation, wherein:

[0016] Figure 1A schematic diagram of the conduction waveform of the switching device in a soft-start circuit in the prior art is shown;

[0017] Figure 2 A schematic diagram of a soft-start circuit based on thyristors and relays in the prior art is shown;

[0018] Figure 3 A schematic diagram of a soft-start circuit based on an inverted series transistor in the prior art is shown;

[0019] Figure 4-6 It shows Figure 3 A schematic diagram of the operation process of the soft-start circuit shown;

[0020] Figure 7 A flowchart illustrating a method for operating a conduction component according to an embodiment of the present disclosure is shown;

[0021] Figure 8 A flowchart illustrating the determination of the shutdown timing in a method of operating a turn-on component according to an embodiment of the present disclosure is shown;

[0022] Figure 9 A schematic diagram of the current waveform is shown when the method of the present disclosure operates the conducting component according to an embodiment of the present disclosure;

[0023] Figure 10-12 A schematic diagram illustrating the operation of a conduction component according to an embodiment of the present disclosure is shown; and

[0024] Figure 13 A block diagram of an example device that can be used to implement embodiments of the present disclosure is shown. Detailed Implementation

[0025] The principles of this disclosure will now be described with reference to various exemplary embodiments shown in the accompanying drawings. It should be understood that the description of these embodiments is merely intended to enable those skilled in the art to better understand and further implement this disclosure, and is not intended to limit the scope of this disclosure in any way. It should be noted that similar or identical reference numerals may be used in the figures where feasible, and similar or identical reference numerals may denote similar or identical functions. Those skilled in the art will readily recognize that alternative embodiments of the structures and methods described herein may be employed without departing from the principles of the invention as described herein.

[0026] The following will combine Figure 1-6 This section details the structure of existing soft-start circuits and the shortcomings of existing soft-start methods. First, refer to... Figure 1 , Figure 1 A schematic diagram of the conduction waveform of the switching device in a soft-start circuit in the prior art is shown.

[0027] like Figure 1 As shown, for inductive loads, existing technologies typically achieve soft-start by gradually increasing the conduction angle of the conducting device in each soft-start cycle. The conduction angle refers to the conduction time of the conducting device within each soft-start cycle. In this way, the current variation in the inductive load is small, allowing the voltage applied across the conducting device to gradually increase from low to high without damaging the conducting device.

[0028] Figure 2 A schematic diagram of a soft-start circuit based on thyristors and relays in the prior art is shown. Figure 2 As shown, each branch of this soft-start circuit for inductive loads (such as three-phase motors) includes a thyristor and a relay connected in parallel. The conduction angle of the thyristor gradually increases every half AC cycle, and finally closes the relay when the conduction angle reaches its maximum, completing the soft start. Due to the inherent characteristics of the thyristor, its conduction loss is relatively large, resulting in a relatively large overall loss in this soft-start circuit.

[0029] Figure 3 A schematic diagram of a soft-start circuit based on an inverted series transistor in the prior art is shown. Figure 3 As shown, each branch of this soft-start circuit for an inductive load (e.g., a three-phase motor) includes conducting components M1-M3, each comprising a transistor connected in reverse series. Because the transistor's conduction losses are lower than those of a thyristor, ... Figure 3 The overall loss of the soft-start circuit shown is less than Figure 2 The soft-start circuit shown below. (The following is in conjunction with...) Figure 4-6 illustrate Figure 3 The operation of the soft-start circuit shown is illustrated using phases A and B as examples.

[0030] Figure 4-6 It shows Figure 2 The diagram illustrates the operation of the soft-start circuit. Figure 4 As shown, the soft-start circuit includes a phase A branch envelope conduction component M1, which comprises transistors S1 and S2 connected in reverse series, and a phase B branch conduction component M2, which comprises transistors S3 and S4 connected in reverse series. Each transistor includes a body diode connected in reverse parallel. In the first cycle of soft-start, assuming the phase A voltage is higher than the phase B voltage, the soft-start controller controls S1 and S4 to conduct and S2 and S3 to turn off. At this time, current flows from the phase A power supply through the body diodes of S1 and S2, and the body diodes of S4 and S3 to the phase B power supply.

[0031] like Figure 5As shown, after the conduction angles of M1 and M2 in the first cycle are reached, the soft-start controller disconnects S1-S4. Since the forward voltage drop across the body diode is approximately 0.7V, the loss of the soft-start circuit in the first cycle is approximately 2 * 0.7V * the current flowing through the body diode during the conduction angle of the first cycle.

[0032] like Figure 6 As shown, in the second cycle of soft start, the voltage of phase A is lower than that of phase B. The soft start controller controls S2 and S3 to turn on and S1 and S4 to turn off. At this time, the current flows from the phase B power supply through the body diodes of S3 and S4, and the body diodes of S2 and S1 to the phase A power supply.

[0033] After the conduction angles of M1 and M2 in the second cycle are reached, the soft-start controller disconnects S1-S4. Since the forward voltage drop across the body diode is approximately 0.7V, the power loss of the soft-start circuit in the second cycle is approximately 2 * 0.7V * the current flowing through the body diode during the conduction angle of the second cycle.

[0034] Repeat the above steps until the conduction angles of M1 and M2 reach their maximum, at which point the soft start will end.

[0035] The above control method does not require detecting the voltage across M1 and M2 or the current flowing through them. It only needs to control the on / off state of M1 and M2 based on the conduction angle, making the control method simple.

[0036] However, due to the voltage drop across the body diode, the above control method will cause M1 and M2 to generate significant losses during the soft-start process, affecting the lifespan of the devices.

[0037] The following will combine Figure 7-12 A detailed description of a backup power delay control circuit according to an exemplary embodiment of this disclosure is provided. First, refer to... Figure 7 , Figure 7 A flowchart illustrating a method of operating a conducting component according to an embodiment of the present disclosure is shown. The conducting component is coupled between an AC power source and an inductive load and includes a first switching device and a second switching device connected in reverse series. The first switching device includes a first body diode connected in reverse parallel with the first switching device, and the second switching device includes a second body diode connected in reverse parallel with the second switching device.

[0038] like Figure 7 As shown, the method of operating the conducting component includes: at 105, in a first cycle, turning on the conducting component with a first conduction angle. At 110, in a second cycle, turning on the conducting component with a second conduction angle greater than the first conduction angle. At 115, wherein, in the first and second cycles, based on the current flowing through the conducting component, the turn-off timing of a first switching device or a second switching device connected in reverse parallel to a first body diode or a second body diode with the same conduction direction as the current direction is determined.

[0039] Through the above embodiments, during the soft-start process, the switching devices within the conductive component are in a conducting state for a certain period. Since the on-state voltage drop of the switching device (e.g., MOSFET) is much smaller than the voltage drop across the body diode, therefore, compared to... Figure 3 Compared to the control method of the soft-start circuit shown in the previous embodiment, the method according to this embodiment can reduce the loss of the soft-start circuit and extend the service life of the conducting components.

[0040] In some embodiments, the method further includes activating the conductive component in at least one third cycle at at least one third conduction angle, wherein the conduction angle used in a later cycle of the first, second, and third cycles is greater than the conduction angle used in a previous cycle. In other embodiments, multiple other cycles may be included, each with a conduction angle in a later cycle greater than the conduction angle in a previous cycle, which may be determined based on specific design requirements and cost.

[0041] In some embodiments, the method further includes providing a turn-off signal to a first or second switching device in response to a zero current. In this way, zero-current turn-off of the conducting component can be achieved. In other embodiments, the conducting component can be turned off in other ways, depending on specific requirements and cost.

[0042] In some embodiments, the method further includes determining the increase in the conduction angle per cycle based on the voltage boost slope of the inductive load and a preset boost curve. In other embodiments, the conduction angle is adjusted in other ways, which may be determined according to specific design requirements and cost.

[0043] Figure 8 A flowchart illustrating the determination of the shutdown timing in a method for operating a turn-on component according to an embodiment of the present disclosure is shown. Figure 8 As shown, determining the turn-off timing based on current includes: at 205, detecting the magnitude of the current; and at 210, in response to the current being less than a threshold, providing a turn-off signal to a first or second switching device connected in reverse parallel to a first or second body diode whose conduction direction is the same as the current direction.

[0044] Figure 9 A schematic diagram of the current waveform is shown when a conducting component is operated according to an embodiment of the present disclosure. For example... Figure 9 As shown, when it is detected at time t1 that the current in the conducting component is less than the threshold I... th When this happens, the controller sends a shutdown signal.

[0045] To minimize losses as much as possible, we expect I th The closer to zero, the better. In some embodiments, I th=0. That is, when the current in the conducting component reaches zero at time t2, the controller issues a turn-off signal.

[0046] However, in actual current detection processes, the detection accuracy of the current sensor will affect the threshold I. th The choice of threshold is crucial. For example, if the current sensor has a detection accuracy of 0.1A, its output may be the same whether the current flowing through the conducting component is 0.1A or 0A. Therefore, in some embodiments, the threshold is determined based on the accuracy of the current detection. In other embodiments, the threshold may be selected in other ways, depending on specific design requirements and cost.

[0047] In some embodiments, the turn-off timing includes the zero-crossing point of the voltage of the conducting component. This is because, in an inductive load, the voltage leads the current by a certain angle. When this angle is small, the current is also close to zero when the voltage reaches zero. Turning off the conducting component at this time can achieve a similar effect to the above-described scheme of turning off the conducting component by detecting that the current is less than a threshold, and can save the need for a current sensor.

[0048] The following is combined Figure 10-12 This section will explain the specific process of controlling the conduction component according to the method of this embodiment. First, refer to... Figure 10 , Figure 10 The conducting component shown is suitable for single-phase inductive loads and can also be used as a single-phase branch of a three-phase inductive load, with the same control method. The conducting component includes two MOSFETs S1 and S2 connected in reverse series, where S1 is connected in reverse parallel with an integrated diode D1, and S2 is connected in reverse parallel with an integrated diode D2.

[0049] like Figure 10 As shown, in the first cycle, the conducting components are turned on at a first conduction angle. At the beginning of the conduction angle, the controller controls both S1 and S2 to be turned on, and current flows through S1 and S2 to the inductive load.

[0050] like Figure 11 As shown, during the process of current reduction, when the controller detects that the current is less than the threshold, the controller controls S2 to disconnect, and at this time the current flows to the load through S1 and D2.

[0051] like Figure 12 As shown, when the controller detects that the current is 0, the controller controls S1 to turn off. At this time, since S2 has been turned off, and D2 will block the reverse current, no reverse current will flow through S1, thus naturally achieving zero-current turn-off of the conducting component.

[0052] The operation is similar when the current is reversed, and will not be described in detail here.

[0053] As can be seen from the above operation process, during soft-start, current only flows through the body diode of the MOSFET during certain moments when the current is relatively small; the current flows through the MOSFET body at other times. Therefore, the losses of the conducting components are greatly reduced throughout the soft-start process.

[0054] In another aspect of this disclosure, an apparatus for operating a conducting component coupled between an AC power source and an inductive load is also disclosed, and including a first switching device and a second switching device connected in reverse series. The first switching device includes a first body diode connected in reverse parallel with the first switching device, and the second switching device includes a second body diode connected in reverse parallel with the second switching device. The apparatus includes: a current sampling device for sampling current in the conducting component; and a controller communicatively connected to the current sampling device and configured to perform the method according to any of the foregoing embodiments.

[0055] In another aspect of this disclosure, a starting device is also disclosed, including the device according to the foregoing embodiments.

[0056] In another aspect of this disclosure, a computer-readable medium is also disclosed having computer-executable instructions stored thereon, which, when run on a processor, perform the method according to the foregoing embodiments.

[0057] Figure 13 A schematic block diagram of an example device 1300 that can be used to implement embodiments of the present disclosure is shown. Device 1300 can be used to implement... Figure 7-8 Methods 100 and 200. Device 1300 can be implemented as the means for operating the conduction component described above.

[0058] As shown in the figure, device 1300 includes a central processing unit (CPU controller) 1301, which can perform various appropriate actions and processes according to computer program instructions stored in read-only memory (ROM) 1302 or loaded from storage unit 1308 into random access memory (RAM) 1303. The controller 1301 may be, for example, the means described above for operating the conducting components. Various programs and data required for the operation of device 1300 may also be stored in RAM 1303. CPU 1301, ROM 1302, and RAM 1303 are interconnected via bus 1304. Input / output (I / O) interface 1305 is also connected to bus 1304.

[0059] Multiple components in device 1300 are connected to I / O interface 1305, including: input unit 1306, such as keyboard, mouse, etc.; output unit 1307, such as various types of monitors, speakers, etc.; storage unit 1308, such as disk, optical disk, etc.; and communication unit 1309, such as network card, modem, wireless transceiver, etc. Communication unit 1309 allows device 1300 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0060] Processing unit 1301 executes the various methods and processes described above, such as methods 100 and 200. For example, in some embodiments, methods 100 and 200 may be implemented as computer software programs or computer program products tangibly contained in a computer-readable medium, such as a non-transient computer-readable medium (e.g., storage unit 1308). In some embodiments, part or all of the computer program may be loaded and / or installed on device 1300 via ROM 1302 and / or communication unit 1309. When the computer program is loaded into RAM 1303 and executed by CPU 1301, one or more steps of methods 100 and 200 described above may be performed. Alternatively, in other embodiments, CPU 1301 may be configured to execute methods 100 and 200 by any other suitable means (e.g., by means of firmware).

[0061] Those skilled in the art will understand that the various steps of the methods disclosed above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using device-executable program code, which can then be stored in a storage device for execution by the computing device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, this disclosure is not limited to any particular combination of hardware and software. For example, some embodiments of this disclosure also include various program modules and / or integrated circuit modules for performing one or more steps of methods 100 and 200 and / or one or more other steps described in other embodiments of this disclosure. These program modules can be included or embodied in a device, such as... Figure 13 Among the 1300 devices.

[0062] It should be understood that although several devices or sub-devices of the device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of this disclosure, the features and functions of two or more devices described above can be embodied in one device. Conversely, the features and functions of one device described above can be further divided and embodied by multiple devices.

[0063] The above are merely optional embodiments of this disclosure and are not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A method of operating a conducting component, the conducting component being coupled between an AC power source and an inductive load, and comprising a first switching device and a second switching device connected in reverse series, the first switching device comprising a first body diode connected in reverse parallel with the first switching device, the second switching device comprising a second body diode connected in reverse parallel with the second switching device, the method comprising: In the first cycle, the conducting component is activated at a first conduction angle. In the second cycle, the conducting component is activated at a second conduction angle, which is greater than the first conduction angle. In the first cycle and the second cycle, based on the current flowing through the conducting component, the turn-off timing of the first switching device or the second switching device connected in reverse parallel to the first body diode or the second body diode, whose conduction direction is the same as the current direction, is determined.

2. The method of claim 1, wherein determining the turn-off timing based on the current comprises: Detect the magnitude of the current; as well as In response to the current being less than a threshold, the first switching device or the second switching device, which is connected in parallel in the opposite direction to the first body diode or the second body diode and whose conduction direction is the same as the current direction, provides a turn-off signal.

3. The method of claim 1, further comprising activating the conducting component at at least one third conduction angle in at least one third cycle, wherein the conduction angle used in the later cycle of the first cycle, the second cycle, and the third cycle is greater than the conduction angle used in the earlier cycle.

4. The method of claim 1, further comprising providing a turn-off signal to the first switching device or the second switching device in response to the current being equal to zero.

5. The method according to claim 1, further comprising determining the increase in the conduction angle for each cycle based on the voltage boost slope of the inductive load and a preset boost curve.

6. The method of claim 2, wherein the threshold is determined based on the accuracy of the current detection.

7. The method of claim 1, wherein the turn-off timing includes the voltage zero-crossing point of the turn-on component.

8. An apparatus for operating a conducting component, the conducting component being coupled between an AC power source and an inductive load, and comprising a first switching device and a second switching device connected in reverse series, the first switching device including a first body diode connected in reverse parallel with the first switching device, the second switching device including a second body diode connected in reverse parallel with the second switching device, the apparatus comprising: A current sampling device for sampling the current in the conducting component; as well as The controller is communicatively connected to the current sampling device and configured to perform the method according to any one of claims 1-7.

9. A starting device, comprising the device according to claim 8.

10. A computer-readable medium having stored thereon computer-executable instructions, which, when executed on a processor, perform the method according to any one of claims 1-7.

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