Control method of resonant conversion device, resonant conversion device and coated power supply

Abstract

The application relates to a control method of a resonant conversion device, the resonant conversion device and a coated power supply. The control method comprises the following steps: determining a zero-crossing advance moment of an output current corresponding to a bridge arm in the resonant conversion device; acquiring an output moment of a driving signal output to a switch tube of the resonant conversion device; and determining a target moment of outputting the driving signal to the switch tube according to the output moment and the zero-crossing advance moment. The control method of the resonant conversion device can ensure that the resonant conversion device always works in an inductive state during the process of load conversion.

Description

Technical Field

[0001] This application relates to the field of electronic equipment technology, and in particular to a control method for a resonant converter, a resonant converter, and a coating power supply. Background Technology

[0002] With the rapid development of power electronics technology, people's demands for various electronic products are increasing, and the demand for DC power supplies is also rising. Therefore, DC power supplies with wide input and output ranges are needed. Resonant converters can achieve both wide input and wide output ranges. Under frequency conversion modulation, the peak gain frequency of a resonant converter increases with the lighter the load. To achieve zero-voltage turn-on and ensure monotonic gain, the resonant converter needs to operate in an inductive state.

[0003] However, existing technology cannot guarantee that the resonant converter will always operate in an inductive state during load changes. Summary of the Invention

[0004] Therefore, it is necessary to provide a control method, a resonant converter, and a coating power supply that can ensure the resonant converter always operates in an inductive state during load changes, in order to address the above-mentioned technical problems.

[0005] In a first aspect, this application provides a control method for a resonant converter, the method comprising:

[0006] Determine the zero-crossing lead time of the output current corresponding to the bridge arm in the resonant converter. The zero-crossing lead time refers to the time before the zero-crossing time of the output current.

[0007] Obtain the output time of the drive signal output to the switching transistor of the resonant converter;

[0008] Based on the output time and the zero-crossing lead time, determine the target time for outputting the drive signal to the switching transistor.

[0009] In one embodiment, determining the target time for outputting the drive signal to the switching transistor based on the output time and the zero-crossing lead time includes:

[0010] The output time is compared with the zero-crossing lead time to obtain the comparison result; the comparison result is used to represent the time logic between the output time and the zero-crossing lead time.

[0011] The target time is determined based on the comparison results.

[0012] In one embodiment, determining the target time based on the comparison result includes:

[0013] If the comparison result shows that the output time is before the zero-crossing lead time, then the output time is taken as the target time.

[0014] If the comparison result shows that the output time is after the zero-crossing lead time, then the zero-crossing lead time is taken as the target time.

[0015] In one embodiment, determining the zero-crossing lead time of the output current corresponding to the bridge arm in the resonant converter includes:

[0016] Determine the voltage signal corresponding to the output current;

[0017] Determine the zero-crossing lead time based on the voltage signal.

[0018] In one embodiment, determining the zero-crossing lead time based on the voltage signal includes:

[0019] The moment when the absolute value of the voltage signal amplitude decreases to the first preset threshold is determined as the zero-crossing lead moment.

[0020] In one embodiment, determining the zero-crossing lead time based on the voltage signal includes:

[0021] Based on the voltage signal, determine the leading voltage signal; the leading voltage signal is the signal obtained by shifting the waveform phase of the voltage signal forward.

[0022] The zero-crossing lead time is determined based on the leading voltage signal.

[0023] In one embodiment, determining the zero-crossing lead time based on the lead voltage signal includes:

[0024] The zero-crossing time of the leading voltage signal is defined as the zero-crossing leading time.

[0025] In one embodiment, determining the zero-crossing lead time based on the lead voltage signal includes:

[0026] The moment when the absolute value of the amplitude of the leading voltage signal decreases to the second preset threshold is determined as the zero-crossing leading moment.

[0027] Secondly, one embodiment of this application provides a resonant converter, including a power supply module, a switching module, a resonant module, and a control module;

[0028] The power supply module is electrically connected to the switch module, and the power supply module is used to transmit DC power to the switch module.

[0029] The switching module is connected between the power supply module and the resonant module. The switching module is used to convert the DC power output by the power supply module into AC power according to the drive signal output by the control module. The resonant module is used to perform resonant conversion of AC power.

[0030] The control module is used to execute the steps of the method provided in the first aspect.

[0031] In one embodiment, the switching module includes multiple bridge arms, each corresponding to an output current.

[0032] Thirdly, one embodiment of this application also provides a coating power supply, which includes the resonant converter provided in the second aspect above, for supplying power to a plasma load.

[0033] Fourthly, one embodiment of this application also provides a method for controlling a coating power supply, the method comprising:

[0034] In response to the received operating voltage requirement of the coating apparatus, the resonant converter in the coating power supply is controlled to supply power to the coating apparatus according to the method provided in the first aspect above.

[0035] This application provides a control method for a resonant converter, the resonant converter itself, and a coating power supply. The method involves determining the zero-crossing lead time of the output current corresponding to the bridge arm in the resonant converter; obtaining the output time of the drive signal output to the switching transistor of the resonant converter; and determining the target time for outputting the drive signal to the switching transistor based on the output time and the zero-crossing lead time. In this embodiment, the target time for outputting the drive signal to the switching transistor is determined based on the zero-crossing lead time of the output current corresponding to the bridge arm in the resonant converter and the output time. The output time ensures that the resonant converter operates in an inductive state. The zero-crossing lead time of the output current is related to the load connected to the resonant converter, so the final determined target time is load-dependent; different loads result in different target times. This allows the resonant converter to continue operating in an inductive state even when the load changes, better ensuring zero-voltage turn-on of the switching transistor under extreme operating conditions. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the gain curve of a resonant converter in one embodiment;

[0037] Figure 2 This is a flowchart illustrating the steps of a control method for a resonant converter in one embodiment;

[0038] Figure 3 This is a flowchart illustrating the steps of the control method for the resonant converter in another embodiment;

[0039] Figure 4 This is a flowchart illustrating the steps of the control method for the resonant converter in another embodiment;

[0040] Figure 5 This is a flowchart illustrating the steps of the control method for the resonant converter in another embodiment;

[0041] Figure 6 The waveform of the voltage signal is shown in one embodiment.

[0042] Figure 7 This is a flowchart illustrating the steps of the control method for the resonant converter in another embodiment;

[0043] Figure 8 This is a flowchart illustrating the steps of the control method for the resonant converter in another embodiment;

[0044] Figure 9 This is a flowchart illustrating the steps of the control method for the resonant converter in another embodiment;

[0045] Figure 10 This is a waveform diagram of the drive signal output by the control module to the switching transistor in one embodiment;

[0046] Figure 11 The waveform diagram shows the drive signal output by the control module to the switching transistor in another embodiment.

[0047] Figure 12 This is a schematic diagram of the resonant converter in one embodiment;

[0048] Figure 13 This is a schematic diagram of the resonant converter in another embodiment;

[0049] Figure 14 This is a schematic diagram of the driving logic of the switching transistor in a resonant converter in one embodiment;

[0050] Figure 15 This is a schematic diagram of the connection method of the primary winding of a three-phase transformer in one embodiment;

[0051] Figure 16 This is a schematic diagram of the connection method of the secondary winding of a three-phase transformer in one embodiment;

[0052] Figure 17 This is a schematic diagram showing the connection method of another capacitor in the resonant module in one embodiment. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0054] Before detailing the technical solutions of the embodiments of this disclosure, the technical background or evolution of the embodiments of this disclosure will be introduced first. In applications such as DC sputtering coating, there is a need for DC power supplies with wide input and wide output. Resonant converters can achieve wide input and wide output. Under frequency conversion modulation, the frequency point corresponding to the peak gain of the resonant converter is higher as the load becomes lighter. In order to achieve zero-voltage turn-on of the resonant converter and ensure monotonic gain, the resonant converter needs to operate in an inductive state. For example, the gain curve of a multiphase LCC resonant converter is as follows... Figure 1 As shown. When the switching frequency is greater than the frequency limiting point, the resonant converter operates in an inductive state. From Figure 1 As can be seen, in the inductive state, as the load decreases from heavy to light, the switching frequency corresponding to the resonant peak increases, and the peak gain also increases. In existing technologies, the parameters of the main circuit in the resonant converter are typically adjusted to ensure that the resonant converter operates in an inductive state within a specific load range. However, the existing methods limit parameter design, leading to higher voltage, current, or thermal stress in the resonant converter, limiting the supported load range, and failing to guarantee that the resonant converter operates in an inductive state as the load continuously changes. Therefore, this application provides a control method for a resonant converter device.

[0055] In one embodiment, such as Figure 2 As shown, a control method for a resonant converter is provided. This embodiment illustrates the application of this method to a control module. In this embodiment, the method includes the following steps:

[0056] Step 200: Determine the zero-crossing lead time of the output current corresponding to the bridge arm in the resonant converter. The zero-crossing lead time refers to the time before the zero-crossing time of the output current.

[0057] A resonant converter includes bridge arms, and the output current of each bridge arm can be called the resonant current. The output current of a resonant converter corresponds to moments from early to late. The zero-crossing moment of the output current corresponding to a bridge arm in a resonant converter refers to the moment when the output current is zero. The zero-crossing lead moment is the moment before the zero-crossing moment of the output current, that is, the moment earlier than the zero-crossing moment.

[0058] The control module determines the zero-crossing lead time of the output current corresponding to the bridge arm in the resonant converter. This embodiment does not limit the specific method for determining the zero-crossing lead time, as long as the function can be achieved.

[0059] Step 210: Obtain the output time of the drive signal output to the switching transistor of the resonant converter.

[0060] When controlling the resonant converter, the control module outputs drive signals to the switching transistors within the converter to activate them. The control module obtains the output timing of these drive signals. This output timing is pre-calculated. In other words, the control module first calculates the output timing of the drive signals to the switching transistors and then outputs the drive signals accordingly.

[0061] In an optional embodiment, the control module includes a calculation module that can calculate the output time of the drive signal output to the switching transistor of the resonant converter.

[0062] Step 220: Determine the target time for outputting the drive signal to the switching transistor based on the output time and the zero-crossing lead time.

[0063] After the control module obtains the zero-crossing lead time and the output time, it determines the target time for outputting the drive signal to the switching transistor based on the zero-crossing lead time and the output time. That is, by comparing the zero-crossing lead time and the output time, the target time for the control module to output the drive signal to the switching transistor is determined.

[0064] The resonant converter can have multiple bridge arms. By using the method provided in this embodiment to output a driving signal for each bridge arm, it can be ensured that the resonant converter operates in an inductive state.

[0065] The control method for the resonant converter provided in this application determines the zero-crossing lead time of the output current corresponding to the bridge arm in the resonant converter; obtains the output time of the drive signal output to the switching transistor of the resonant converter; and determines the target time for outputting the drive signal to the switching transistor based on the output time and the zero-crossing lead time. In this embodiment, the target time for outputting the drive signal to the switching transistor is determined based on the zero-crossing lead time of the output current corresponding to the bridge arm in the resonant converter and the output time. The output time ensures that the resonant converter operates in an inductive state. The zero-crossing lead time of the output current is related to the load connected to the resonant converter, so the final determined target time is load-related. Different loads result in different target times, thereby enabling the resonant converter to still operate in an inductive state during load changes, and better ensuring the zero-voltage turn-on of the switching transistor under extreme operating conditions.

[0066] In one embodiment, such as Figure 3 As shown, this relates to an implementation method for determining the target time for outputting a drive signal to the switching transistor based on the output time and the zero-crossing lead time. The steps of this implementation method include:

[0067] Step 300: Compare the output time with the zero-crossing lead time to obtain the comparison result; the comparison result is used to represent the time logic between the output time and the zero-crossing lead time.

[0068] After acquiring the output time and zero-crossing lead time, the control module compares the output time and the zero-crossing lead time to obtain a comparison result. The comparison result represents the time logic between the output time and the zero-crossing lead time. In other words, the comparison result includes output times between the zero-crossing lead times (i.e., the output time is earlier than the zero-crossing lead time) and output times after the zero-crossing lead time (i.e., the output time is later than the zero-crossing lead time).

[0069] Step 310: Determine the target time based on the comparison results.

[0070] After determining the comparison result between the output time and the zero-crossing lead time, the control module determines the target time based on this comparison result. In other words, the time logic between the control module's output time and the zero-crossing lead time determines the target time.

[0071] In one embodiment, such as Figure 4 As shown, this relates to an implementation method for determining the target time based on comparison results. The steps of this implementation method include:

[0072] Step 400: If the comparison result shows that the output time is before the zero-crossing lead time, then the output time is taken as the target time.

[0073] If the control module compares the output time and the zero-crossing lead time and finds that the output time is between the zero-crossing lead time and the zero-crossing lead time (i.e., the output time is earlier than the zero-crossing lead time), then the output time of the drive signal output to the switch of the resonant converter is determined as the target time for outputting the drive signal to the switch.

[0074] Step 410: If the comparison result shows that the output time is after the zero-crossing lead time, then the zero-crossing lead time is taken as the target time.

[0075] If the control module compares the output time and the zero-crossing lead time and finds that the output time is after the zero-crossing lead time (i.e., the output time is later than the zero-crossing lead time), then the zero-crossing lead time of the output current corresponding to the bridge arm in the resonant converter is determined as the target time for outputting the drive signal to the switching transistor.

[0076] In this embodiment, the control module determines the target time by comparing the output time with the zero-crossing lead time and based on the comparison result. This method is simple, quick, and easy to implement.

[0077] In one embodiment, such as Figure 5As shown, this relates to an implementation method for determining the zero-crossing lead time of the output current corresponding to the bridge arm in a resonant converter. The steps of this implementation method include:

[0078] Step 500: Determine the voltage signal corresponding to the output current.

[0079] After determining the output current corresponding to the bridge arm in the resonant converter, the control module determines the voltage signal corresponding to that output current. Specifically, after obtaining the output current, the control module converts the current signal into a voltage signal.

[0080] Step 510: Determine the zero-crossing lead time based on the voltage signal.

[0081] After receiving the voltage signal, the control module determines the zero-crossing lead time, that is, it determines the time in the voltage signal that is earlier than the zero-crossing time.

[0082] In this embodiment, the control module determines the zero-crossing lead time by determining the voltage signal corresponding to the output current. This method is simple, quick, and easy to implement.

[0083] In one embodiment, an implementation method for determining the zero-crossing lead time based on a voltage signal includes the following steps:

[0084] The moment when the absolute value of the voltage signal amplitude decreases to the first preset threshold is determined as the zero-crossing lead moment.

[0085] The first preset threshold can be set by the user and stored in the control module. The first preset threshold is greater than zero. After receiving the voltage signal, the control module monitors the amplitude of the voltage signal in real time. When the absolute value of the amplitude decreases to the preset first threshold, the time corresponding to the first preset threshold is determined as the zero-crossing lead time.

[0086] In an optional embodiment, the waveform of the voltage signal is as follows: Figure 6 The sine wave shown. Figure 6 The zero-crossing times of the voltage signal are t1, t2, t3, and t4, and the zero-crossing lead time is t. 1-id t 2-id t 3-id and t 4-id .

[0087] In this embodiment, the method of determining the zero-crossing lead time by directly reducing the absolute value of the voltage signal amplitude to the first preset threshold is simple, easy to understand, and easy to implement.

[0088] In one embodiment, see Figure 7 This involves another implementation method for determining the zero-crossing lead time based on a voltage signal, the steps of which include:

[0089] Step 700: Determine the leading voltage signal based on the voltage signal; the leading voltage signal is the signal obtained by shifting the waveform phase of the voltage signal forward.

[0090] After receiving the voltage signal, the control module determines the leading voltage signal. The phase of the leading voltage signal leads the phase of the voltage signal.

[0091] In an optional embodiment, the control module transmits the voltage signal to an inductor to obtain a leading voltage signal.

[0092] In another alternative embodiment, the control module directly shifts the phase of the obtained voltage signal waveform forward by a preset phase to obtain a leading voltage signal.

[0093] Step 710: Determine the zero-crossing lead time based on the lead voltage signal.

[0094] After receiving the lead voltage signal, the control module determines the zero-crossing lead time based on the lead voltage signal. This embodiment does not limit the specific method for determining the lead and zero-crossing lead times based on the lead voltage signal, as long as the function can be achieved.

[0095] In this embodiment, another method is provided to determine the zero-crossing lead time by using a leading voltage signal determined from a voltage signal. Users can choose the method to determine the zero-crossing lead time according to their actual usage scenario.

[0096] Please see Figure 8 In one embodiment, an implementation for determining the zero-crossing lead time based on a leading voltage signal includes the following steps:

[0097] Step 800: Determine the zero-crossing time of the leading voltage signal as the zero-crossing leading time.

[0098] If the phase of the leading voltage signal leads the phase of the voltage signal, and the time corresponding to the first amplitude in the leading voltage signal is earlier than the time corresponding to the first amplitude in the voltage signal, then after obtaining the leading voltage signal, the control module determines the zero-crossing time of the leading voltage signal as the zero-crossing leading time, that is, it determines the time corresponding to the zero amplitude in the leading voltage signal as the zero-crossing leading time.

[0099] Please continue reading Figure 8 In one embodiment, another implementation involves determining the zero-crossing lead time based on a leading voltage signal, the steps of which include:

[0100] Step 810: Determine the time when the absolute value of the amplitude of the leading voltage signal decreases to the second preset threshold as the zero-crossing leading time.

[0101] The second preset threshold can be set by the user and stored in the control module. The second preset threshold is greater than zero. The second preset threshold can be the same as or different from the first preset threshold.

[0102] After receiving the leading voltage signal, the control module monitors the amplitude of the leading voltage signal in real time. When the absolute value of the amplitude decreases to a preset second threshold, the time corresponding to the second preset threshold is determined as the zero-crossing leading time.

[0103] The above embodiments provide two implementation methods for determining the zero-crossing lead time based on the lead voltage signal. Users can choose according to their actual needs, making the control method of the resonant converter highly practical.

[0104] Please see Figure 9 One embodiment of this application provides a control method for a resonant converter, the steps of which include:

[0105] Step 900: Determine the voltage signal corresponding to the output current of the bridge arm in the resonant converter.

[0106] Step 910: The moment when the absolute value of the voltage signal amplitude decreases to the first preset threshold is determined as the zero-crossing lead time; where the zero-crossing lead time refers to the moment before the zero-crossing time of the output current.

[0107] Step 920: Obtain the output time of the drive signal output to the switching transistor of the resonant converter;

[0108] Step 930: Compare the output time with the zero-crossing lead time to obtain the comparison result; the comparison result is used to represent the time logic between the output time and the zero-crossing lead time.

[0109] Step 940: If the comparison result shows that the output time is before the zero-crossing lead time, then the output time is taken as the target time.

[0110] Step 950: If the comparison result shows that the output time is between the zero-crossing and leading times, then the zero-crossing and leading times are taken as the target time.

[0111] In an optional embodiment, such as Figure 6 As shown, the control module can anticipate the zero-crossing time t. 2-id t 4_id The voltage signal amplitude is determined at a specific moment before it crosses zero from negative to positive. Similarly, the control module can determine the zero-crossing time t ahead of the signal. 1-id t 3-id This determines that the voltage signal amplitude is about to cross zero from positive to negative.

[0112] When the resonant converter operates in an inductive state and the modulation method is frequency conversion modulation, the control module will send a drive signal to the switching transistors S1 and S4 of the first bridge arm during the interval between two adjacent zero crossings in the voltage signal, so that the switching transistors S1 and S4 perform a switching action.

[0113] During the negative half-cycle of the voltage signal, in the time interval between t1 and t2, the control module outputs a drive signal DR to the switch S4 of the first bridge arm. leg1l-off Synchronously output drive signal DR to switch S1 leg1h-on If the control module determines that the output time of the drive signal to switch S4 and switch S1 is ahead of the zero-crossing time t... 2-id Before a certain time, drive signals are normally output to switches S4 and S1, meaning the output time is used as the target time for the output drive signal. For example... Figure 10 As shown, waveform A is the waveform of the drive signal output to switch S1 calculated by the calculation module in the control module; waveform B is the waveform of the drive signal output to switch S1 by the control module in actual use; waveform C is the waveform of the drive signal output to switch S4 calculated by the calculation module in the control module; and waveform D is the waveform of the drive signal output to switch S4 by the control module in actual use.

[0114] If the control module determines that the output time of the drive signal to switch S4 and switch S1 is ahead of the zero-crossing time t 2-id Then, at the zero-crossing time t... 2-id The drive signal is output to switches S4 and S1, with the zero-crossing lead time used as the target time for the output drive signal. For example... Figure 11 As shown, waveform E is the waveform of the drive signal output by the calculation module in the control module to the switch S1; waveform F is the waveform of the drive signal output by the control module to the switch S1 during actual use; waveform G is the waveform of the drive signal calculated by the calculation module in the control module and output to the switch S4; and waveform H is the waveform of the drive signal output by the control module to the switch S4 during actual use.

[0115] During the positive half-cycle of the voltage signal, in the time interval between t2 and t3, the control module sends the drive signal DR to the switch S1 of the first bridge arm. leg1h-off Synchronously output drive signal DR to switch S4 leg1l-on If the control module determines that the output time of the drive signal to switch S1 and switch S4 is ahead of the zero-crossing time t... 3-id Before a certain time, drive signals are normally output to switches S4 and S1, meaning the output time is used as the target time for the output drive signal. For example... Figure 10As shown, waveform A is the waveform of the drive signal output to switch S1 calculated by the calculation module in the control module; waveform B is the waveform of the drive signal output to switch S1 by the control module in actual use; waveform C is the waveform of the drive signal output to switch S4 calculated by the calculation module in the control module; and waveform D is the waveform of the drive signal output to switch S4 by the control module in actual use.

[0116] If the control module determines that the output time of the drive signal to switch S4 and switch S1 is ahead of the zero-crossing time t 3-id Then, at the zero-crossing time t... 3-id The drive signal is output to switches S4 and S1, with the zero-crossing lead time used as the target time for the output drive signal. For example... Figure 11 As shown, waveform E is the waveform of the drive signal output by the calculation module in the control module to the switch S1; waveform F is the waveform of the drive signal output by the control module to the switch S1 during actual use; waveform G is the waveform of the drive signal calculated by the calculation module in the control module and output to the switch S4; and waveform H is the waveform of the drive signal output by the control module to the switch S4 during actual use.

[0117] The control module treats the switching transistors on the first, second, and third bridge arms of the resonant module in the same way. After outputting the drive signal using the above method, it can be determined that the resonant converter always operates in an inductive state during the load change process.

[0118] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0119] In one embodiment, such as Figure 12As shown, a resonant converter 10 is provided. The resonant converter 10 includes a power supply module 11, a switching module 12, a resonant module 13, and a control module 14. The power supply module 11, the switching module 12, and the resonant module 13 are electrically connected in sequence. In other words, the switching module 12 includes a first terminal and a second terminal, the resonant module 13 includes a first terminal and a second terminal, the output terminal of the power supply module 11 is connected to the first terminal of the switching module 12, the second terminal of the switching module 12 is connected to the first terminal of the resonant module 13, and the second terminal of the control module 13 is used to connect to a load; that is, the switching module 12 is connected between the power supply module 11 and the resonant module 13.

[0120] The power supply module 11 is used to output DC power to the switch module 12. Specifically, as shown... Figure 13 As shown, the power supply module 11 is a power source capable of outputting DC power, and the voltage of this power source is V. in V in =V BUSP -V BUSN The switching module 12 includes at least two bridge arms, each of which includes two switching transistors.

[0121] The switching module 12 is connected between the power supply module 11 and the resonant module 13. The switching module 12 is used to convert the DC power output from the power supply module 11 into AC power according to the drive signal output by the control module 14. The resonant module 13 is used to perform resonant conversion on the AC power. The control module 14 is used to execute the control method of the resonant converter device provided in the above embodiment.

[0122] The control module 14 outputs a drive signal to the switch module 12 according to the control method of the resonant converter provided in the above embodiment. The switch module 12 converts the DC power received from the power supply module 11 into AC power according to the output drive signal. The switch module 12 transmits the converted AC power to the resonant module 13, which performs resonant conversion on the received AC power, that is, adjusts the frequency and voltage of the AC power.

[0123] The control module 14 may be a computer device, a microprocessor chip or other device, and the computer device may be, but is not limited to, an industrial computer, a laptop computer, a smartphone, a tablet computer and a portable wearable device.

[0124] The resonant converter 10 can be a half-bridge LCC converter, a full-bridge LCC converter, or a multiphase LCC converter. The resonant module 13 in the resonant converter 10 can be an LC series resonant module, an LLC resonant module, or an LCC resonant module. This embodiment does not limit the specific type of the resonant converter 10, as long as it can achieve its function.

[0125] In this embodiment, the resonant converter 10 includes a power supply module 11, a switching module 12, a resonant module 13, and a control module 14. The power supply module 11 is electrically connected to the switching module 12 and is used to transmit direct current (DC) to the switching module 12. The switching module 12 is connected between the power supply module 11 and the resonant module 13. The switching module 12 is used to convert the DC output from the power supply module 11 into alternating current (AC) according to the drive signal output by the control module 14. The resonant module 13 is used to perform resonant conversion on the AC. The control module 14 is used to execute the steps of the control method of the resonant converter in the above embodiment. Since the control module 14 in this embodiment executes the steps of the control method in the above embodiment, the resonant converter 10 has all the beneficial effects of the control method of the resonant converter, which will not be elaborated further here.

[0126] In one embodiment, the switching module 12 includes multiple bridge arms, each corresponding to an output current. This embodiment does not limit the specific number of bridge arms in the switching module 12, as long as the function can be achieved.

[0127] In an optional embodiment, each bridge arm in the switching module 12 includes two switching transistors, and the control module 14 outputs a drive signal to each switching transistor to drive each switching transistor to work.

[0128] In an optional embodiment, the resonant converter 10 is a three-phase resonant converter, such as... Figure 13 As shown, the switching module 12 includes three bridge arms, totaling S1 to S66 switching transistors. The types of switching transistors include, but are not limited to, IGBTs (Insulated Gate Bipolar Transistors) and MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors). The resonant module 13 is an LCC resonant module, including three LCC resonant units. Each resonant unit includes one inductor and two capacitors; the inductor and one capacitor are connected in series, and the inductor and the other capacitor are connected in parallel. The parallel resonant capacitors can be connected in a star or delta configuration. Figure 13 Midpoint M of the first bridge arm a The corresponding output current is i a The midpoint M of the second bridge arm b The corresponding output current is i b The midpoint M of the third bridge arm c The corresponding output current is i c .

[0129] Under frequency conversion modulation Figure 13 The driving logic of each switch is as follows: Figure 14As shown. From Figure 14 In China, DR leg1h To output the drive signal to the switching transistor S1, DR leg1l This is the drive signal output to switch S4; DR leg2h To output the drive signal to the switching transistor S3, DR leg2l This is the drive signal output to the switching transistor S6; DR leg3h To output the drive signal to the switching transistor S5, DR leg3l This is the drive signal output to the switching transistor S2. Figure 12 As can be seen from the diagram: in the first bridge arm, the drive signals of switch S1 and switch S4 are complementary, that is, switch S1 and switch S4 are complementary in conduction; in the second bridge arm, the drive signals of switch S3 and switch S6 are complementary, that is, switch S3 and switch S6 are complementary in conduction; in the third bridge arm, the drive signals of switch S1 and switch S4 are complementary, that is, switch S5 and switch S2 are complementary in conduction. The drive signals of switches S1, S3 and S5 are sequentially delayed by a preset angle, typically 120°.

[0130] Please continue reading Figure 13 In an optional embodiment, the resonant converter 10 may further include a transformer 15 and a rectifier-filter module 16. The transformer 15 includes a first terminal and a second terminal, and includes an initial winding and a secondary winding. The initial winding serves as the first terminal of the transformer 15, and the secondary winding serves as the second terminal. The rectifier-filter module 16 includes a first terminal and a second terminal. The first terminal of the transformer 15 is connected to the second terminal of the resonant module 13, and the second terminal of the transformer 15 is connected to the first terminal of the rectifier-filter module 16. The second terminal of the rectifier-filter module 16 is used for connection to a load.

[0131] Transformer 15 is used to convert the voltage of the AC power after resonance transformation by resonant module 13, and transmit the converted AC power to rectifier and filter module 16. Rectifier and filter module 16 is used to convert the received AC power into DC power and filter the DC power.

[0132] When the resonant converter 10 includes a transformer 15, another capacitor in the resonant module 13 can be connected in parallel to the initial winding of the transformer 15 or in parallel to the secondary winding of the transformer 15.

[0133] In an optional embodiment, if the resonant converter 10 is a three-phase resonant converter, then the transformer 15 is a three-phase transformer. The primary and secondary windings of the three-phase transformer can be connected in a star configuration or a delta configuration. The two connection methods for the primary winding of the three-phase transformer are as follows: Figure 15 As shown, there are two connection methods for the secondary winding of a three-phase transformer. Figure 16 As shown. Two connection methods are shown for the other capacitor in resonant module 13 connected in parallel to the initial winding of transformer 15, and two connection methods are shown for the other capacitor connected in parallel to the secondary winding of transformer 15. Figure 17 As shown. Figure 15 , Figure 16 and Figure 17 T in sa T sb T sc T pa T pb T pc This is the connection point between another capacitor in transformer 15 and resonant module 13 and the inductor in rectifier filter module 16 and resonant module 13.

[0134] The three-phase resonant converter has wide input and output capabilities, as well as high gain under light load. It also has a narrower switching frequency range under the same load range and lower requirements for the rectifier module under the same ripple requirements.

[0135] One embodiment of this application provides a coating power supply, which includes the resonant converter as described in the above embodiment. This coating power supply is used to supply power to a plasma load.

[0136] Using the coating power supply provided in this embodiment to power the plasma load results in less energy storage and can reduce the hazards caused by arcing that may occur in the plasma load.

[0137] In a preferred embodiment, when the resonant converter in the coating power supply is a multiphase resonant converter, compared with a full-bridge resonant converter, it has a narrower switching frequency range within the same load range and lower requirements for the rectifier module under the same ripple requirements, while having the same wide input and output capabilities and high gain under light load. This reduces the energy storage required for the coating power supply output and more effectively mitigates the hazards caused by arcing that may occur in the plasma load.

[0138] The coating power supply provided in this embodiment includes a resonant converter, and the coating power supply has all the beneficial effects of the resonant converter, which will not be elaborated here.

[0139] One embodiment of this application provides a method for controlling a coating power supply, the method comprising the following steps:

[0140] In response to the received operating voltage requirement of the coating apparatus, the resonant converter in the coating power supply is controlled to supply power to the coating apparatus according to the method provided in the above embodiments.

[0141] The coating apparatus is a DC sputtering coating device. The chamber of the coating apparatus contains a target and a substrate, and is filled with an inert gas (e.g., argon) of a specific concentration. The target is a plasma target used to deposit plasma metal material onto the workpiece. After the workpiece is placed in the chamber, the coating process begins. Upon receiving the voltage requirement for operation, the control module in the resonant converter of the coating power supply executes the control method of the resonant converter provided in the above embodiment. This causes the coating power supply to apply DC power between the target and substrate electrodes. The inert gas in the chamber undergoes glow discharge to generate charged ions. Under the influence of the electric field, these charged ions accelerate and bombard the target surface. During bombardment, the charged ions strip atoms from the target surface, and the sputtered target atoms deposit on the substrate surface, achieving coating. During the bombardment of the target, the charged ions generate secondary electrons, which then collide with the inert gas atoms, forming more charged ions. This requires the coating power supply to provide a larger current to maintain the plasma.

[0142] It is understandable that during the coating process using a coating power supply, when no DC power is applied between the target and substrate electrodes, the plasma can be equivalent to a resistor with infinite resistance. As the coating power supply applies DC power between the target and substrate electrodes, the resistance of the plasma decreases. In other words, the resistance of the plasma changes during the coating process. Using the control method of the coating power supply provided in this embodiment, when powering the coating device, it is possible to ensure that the resonant converter in the coating power supply always operates in an inductive state. This allows the coating power supply to achieve zero-voltage switching of the switching module even when the load continuously changes, and ensures that the coating power supply has a higher gain capability under light load than under heavy load. Furthermore, when the load continuously changes, the functional relationship between the gain of the coating power supply and the frequency of the switching module remains monotonic, thereby improving the controllability of the coating power supply.

[0143] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0144] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A control method for a resonant converter, characterized in that, The method includes: Determine the zero-crossing lead time of the output current corresponding to the bridge arm in the resonant converter. The zero-crossing lead time refers to the time before the zero-crossing time of the output current. Obtain the output time of the drive signal output to the switching transistor of the resonant converter; Based on the output time and the zero-crossing lead time, determine the target time for outputting the drive signal to the switching transistor; Determining the target time for outputting the drive signal to the switching transistor based on the output time and the zero-crossing lead time includes: The output time and the zero-crossing lead time are compared to obtain a comparison result; the comparison result is used to represent the time logic between the output time and the zero-crossing lead time. If the comparison result is that the output time is before the zero-crossing lead time, then the output time is taken as the target time; if the comparison result is that the output time is after the zero-crossing lead time, then the zero-crossing lead time is taken as the target time.

2. The method according to claim 1, characterized in that, Determining the zero-crossing lead time of the output current corresponding to the bridge arm in the resonant converter includes: Determine the voltage signal corresponding to the output current; The zero-crossing lead time is determined based on the voltage signal.

3. The method according to claim 2, characterized in that, Determining the zero-crossing lead time based on the voltage signal includes: The moment when the absolute value of the amplitude of the voltage signal decreases to a first preset threshold is determined as the zero-crossing lead time.

4. The method according to claim 2, characterized in that, Determining the zero-crossing lead time based on the voltage signal includes: Based on the voltage signal, a leading voltage signal is determined; the leading voltage signal refers to the signal obtained by shifting the waveform phase of the voltage signal forward. The zero-crossing lead time is determined based on the leading voltage signal.

5. The method according to claim 4, characterized in that, Determining the zero-crossing lead time based on the leading voltage signal includes: The zero-crossing time of the leading voltage signal is determined as the zero-crossing leading time.

6. The method according to claim 4, characterized in that, Determining the zero-crossing lead time based on the leading voltage signal includes: The moment when the absolute value of the amplitude of the leading voltage signal decreases to a second preset threshold is determined as the zero-crossing leading moment.

7. The method according to claim 4, characterized in that, Determining the leading voltage signal based on the voltage signal includes: The voltage signal is transmitted to an inductor to obtain the leading voltage signal.

8. The method according to claim 4, characterized in that, Determining the leading voltage signal based on the voltage signal includes: The waveform of the voltage signal is shifted forward by a preset phase to obtain the leading voltage signal.

9. A resonant converter, characterized in that, It includes a power supply module, a switching module, a resonant module, and a control module; The power supply module is electrically connected to the switch module, and the power supply module is used to transmit DC power to the switch module. The switching module is connected between the power supply module and the resonant module. The switching module is used to convert the DC power output by the power supply module into AC power according to the drive signal output by the control module. The resonant module is used to perform resonant conversion on the AC power. The control module is used to perform the steps of the method described in any one of claims 1-8.

10. The resonant converter according to claim 9, characterized in that, The switching module includes multiple bridge arms, each of which corresponds to an output current.

11. A coated power supply, characterized in that, The coating power supply includes a resonant converter as described in any one of claims 9-10, used to supply power to the plasma load.

12. A method for controlling a coating power supply, characterized in that, include: In response to the received operating voltage requirement of the coating apparatus, the method according to any one of claims 1-8 controls the resonant converter in the coating power supply to supply power to the coating apparatus.

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