High-frequency ultrasonic power supply, control method thereof and high-frequency ultrasonic equipment

Abstract

The invention relates to the technical field of ultrasonic power supplies, in particular to a high-frequency ultrasonic power supply, a control method thereof and high-frequency ultrasonic equipment. The sampling circuit measures the actual output voltage and current and calculates the actual power of the load; the power controller generates a voltage control instruction according to a difference value between a set power threshold value and the actual power of the load and limits the voltage control instruction through the power amplitude limiter; and the voltage controller generates a current control instruction according to a difference value between the voltage control instruction output by the voltage controller amplitude limiter and the actual output voltage, and the current control instruction is limited by the voltage amplitude limiter. The current controller generates a driving control signal according to the difference value between the current control instruction output by the current controller amplitude limiter and the actual output current, and the driving control signal is limited by the duty ratio amplitude limiter; and the duty ratio of a switching tube of the DC / DC converter is adjusted through a driving control signal output by the duty ratio amplitude limiter, so that the actual power, current and voltage of the load are adjusted. According to the invention, the power supply can always meet the control requirements of voltage, current and power.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic power supplies, and in particular to a high-frequency ultrasonic power supply and a control method thereof, and a high-frequency ultrasonic device. Background Art

[0002] Ultrasonic technology was first used in the late 19th century and early 20th century. After decades of development and research, its application scope has become more and more extensive. Power ultrasonic equipment is mainly composed of ultrasonic transducers and ultrasonic power supplies. Ultrasonic power supplies are composed of power electronic circuits. The AC / DC converter converts the industrial frequency alternating current into direct current, and then the DC / AC converter inverts the electrical signal into high-frequency alternating current; after receiving the high-frequency alternating current, the transducer converts the electrical energy into high-frequency mechanical vibration to generate ultrasonic waves. In recent years, with the continuous advancement of ultrasonic power supply technology, the application scope of ultrasonic power supplies has been greatly expanded. The output frequency of ultrasonic power supplies has gradually developed towards high frequency, covering a frequency range of 20kHz to 10MHz. The increase in output frequency means that the switching frequency of ultrasonic power supply devices increases, the concentration of ultrasonic energy increases, and the depth of action deepens, thereby improving the effect of ultrasonic processing or detection. In addition, with the improvement of control algorithms, the response speed and control accuracy of ultrasonic power supplies are significantly improved, which can meet more complex and sophisticated control requirements. Ultrasonic power supplies are widely used in medicine and industry. In the medical field, ultrasonic technology is used in ultrasonic imaging, ultrasonic scalpels, ultrasonic ablation and other equipment to assist doctors in diagnosis and treatment; in the industrial field, ultrasonic technology is used in cleaning, welding, cutting, grinding and other processes, significantly improving production efficiency and product quality.

[0003] According to the current power electronics technology, ultrasonic power supplies are mainly composed of power electronic circuits composed of fully controlled semiconductor power devices (MOSFET, IGBT). Ultrasonic transducers are usually used as loads at the output end of ultrasonic power supplies, and their output impedance tends to change over a large range with changes in the load. When the load changes dynamically, if the output voltage and output power cannot be adjusted in time, it is very easy to cause overcurrent and overload in the output circuit and the load. In severe cases, it will cause the power devices of the ultrasonic power supply and the load to fail and be damaged. According to the change of load impedance, the power is adjusted. The existing ultrasonic power supply generally adopts a method of real-time detection of the load voltage and current values ​​through a sampling circuit at the output end of the power supply. Based on these voltage and current data, the system can calculate the impedance value and power of the load, and then adjust the duty cycle of the DC / AC converter through an open-loop or closed-loop control strategy, thereby controlling the output power of the ultrasonic power supply. In this control strategy, the closed-loop control is mainly based on feedback adjustment of the output power. When the load impedance changes significantly, the system adjusts the duty cycle to ensure the stability of the output power.

[0004] However, the existing control methods need to detect the instantaneous values ​​of the output voltage and current to accurately measure impedance. Conventional sampling circuits include: sampling resistors and op amp conditioning circuits, Hall sensors, current transformers, etc. However, these sampling circuits are limited by the bandwidth of the components and can generally meet the sampling of output signals of tens of kilohertz and below. When the output frequency of the ultrasonic power supply is increased to hundreds of kHz or even several MHz, the signal distortion and phase lag caused by the conventional voltage and current detection methods have a large impact, and it is difficult to achieve the required control accuracy. The real-time detection methods of high-frequency (MHz level) voltage and current, such as the magnetic ring method, current probe, power meter, etc., are more difficult to insulate, and the volume and cost are also greatly increased accordingly, and some methods are not sufficiently integrable. In addition, this method of closed-loop control based only on output power may cause the output current or voltage to exceed the safety threshold when the load impedance changes over a large range. Considering the resistive load R, according to When the load resistance is low, the current is likely to exceed the threshold; when the load resistance is high, the voltage is likely to exceed the threshold. These voltage and current overlimits can easily lead to damage to the ultrasonic transducer load and power devices of the power supply. However, if the output voltage and current are simply limited, the output power control accuracy may be insufficient, and the output power may be limited and unable to meet the output requirements of the power supply. Summary of the invention

[0005] To this end, the technical problem to be solved by the present invention is to overcome the defects of the existing control method that the cost of detecting the instantaneous values ​​of the output voltage and current is too high, and in the process of large-range changes in load impedance, the output current or voltage may exceed the safety threshold, thereby damaging the ultrasonic transducer load and power supply power devices.

[0006] In order to solve the above technical problems, the present invention provides a high-frequency ultrasonic power supply, comprising:

[0007] Power circuit, including:

[0008] An AC / DC converter, whose input end is connected to an AC power source and whose output end is connected to a DC / AC converter;

[0009] A DC / AC converter, an input end of which is connected to the AC / DC converter, and an output end of which is connected to the load;

[0010] Control loop, including:

[0011] The sampling circuit has an input end connected to the load and an output end connected to the power controller, the voltage controller, and the current controller; the sampling circuit measures the actual output voltage and the actual output current of the load and calculates the actual power of the load;

[0012] After receiving the actual power of the load output by the sampling circuit, the power controller generates a voltage control instruction based on the difference between the set power threshold and the actual power of the load;

[0013] A voltage controller limiter, whose input end is connected to the power controller to limit the voltage control command, and whose output end is connected to the voltage controller;

[0014] After receiving the voltage control instruction output by the voltage controller limiter, the voltage controller generates a current control instruction based on the difference between the voltage control instruction and the actual output voltage of the load;

[0015] A current controller limiter, whose input end is connected to the voltage controller to limit the current control instruction, and whose output end is connected to the current controller;

[0016] After receiving the current control instruction output by the current controller limiter, the current controller generates a drive control signal based on the difference between the current control instruction and the actual output current of the load;

[0017] The duty cycle limiter has an input end connected to the current controller to limit the drive control signal, and an output end is used to output the drive control signal to the DC / AC converter. By adjusting the duty cycle of the switch tube of the DC / AC converter, the voltage output by the DC / AC converter is adjusted, thereby controlling the actual power, actual output current and actual output voltage of the load.

[0018] Preferably, the power circuit further comprises:

[0019] The DC / DC converter has an input end connected to the AC / DC converter output end, and an output end connected to the DC / AC converter input end.

[0020] Preferably, the duty cycle limiter has an input end connected to the current controller to limit the drive control signal, and an output end is used to output the drive control signal to the DC / DC converter, and the voltage output by the DC / DC converter is adjusted by adjusting the duty cycle of the switch tube of the DC / DC converter, so as to control the actual power, current and voltage of the load through the DC / AC converter.

[0021] Preferably, limiting the voltage control instruction by a voltage control limiter includes:

[0022] When the voltage control instruction is greater than the maximum threshold value in the preset voltage range, the voltage control instruction is set to the maximum threshold value in the preset voltage range;

[0023] When the voltage control command is within the preset voltage range, the voltage control command remains unchanged.

[0024] Preferably, limiting the current control instruction by a current control limiter includes:

[0025] When the current control instruction is greater than the maximum threshold value in the preset current range, the current control instruction is set to be the maximum threshold value in the preset current range;

[0026] When the current control command is within the preset current range, the current control command remains unchanged.

[0027] Preferably, limiting the driving control signal by a duty cycle limiter includes:

[0028] When the driving control signal is greater than the maximum threshold value in the preset duty cycle range, the driving control signal is set to the maximum threshold value in the preset duty cycle range;

[0029] When the driving control signal is within the preset duty cycle range, the driving control signal remains unchanged.

[0030] Preferably, the preset duty cycle range is [0, 0.5].

[0031] The present invention also provides a method for controlling a high-frequency ultrasonic power supply, comprising:

[0032] The actual output voltage and the actual output current of the load are measured by a sampling circuit connected to the load, and the actual power of the load is calculated;

[0033] Calculate the difference between the set power threshold and the actual power of the load. The power controller generates a voltage control instruction according to the difference between the set power threshold and the actual power of the load, and limits the voltage control instruction through the voltage control limiter.

[0034] The voltage controller generates a current control command based on the difference between the voltage control command output by the voltage control limiter and the actual output voltage of the load, and limits the current control command through the current control limiter.

[0035] The difference between the current control command output by the current control limiter and the actual output current of the load is calculated, and the current controller generates a drive control signal according to the difference between the current control command output by the current control limiter and the actual output current of the load, and limits the drive control signal through the duty cycle limiter;

[0036] According to the driving control signal output by the duty cycle limiter, the duty cycle of the switch tube of the DC / AC converter is adjusted to adjust the voltage output by the DC / AC converter, thereby controlling the actual power, actual output current and actual output voltage of the load.

[0037] The present invention also provides a high-frequency ultrasonic device, comprising:

[0038] A high frequency ultrasonic power supply as described above;

[0039] The ultrasonic transducer has an input end connected to the output end of the DC / AC converter, and an output end connected to the input end of the control loop.

[0040] The above technical solution of the present invention has the following beneficial effects compared with the prior art:

[0041] The high-frequency ultrasonic power supply and its control method and high-frequency ultrasonic equipment described in the present invention do not require a high-frequency detection and conditioning circuit to detect the instantaneous values ​​of the output voltage and the output current in real time. The actual output voltage and the actual output current of the load are measured through a sampling circuit connected to the load, and the actual power of the load is calculated; by measuring the effective values ​​of the output voltage and the output current of the load, the cost of the detection circuit and related components is effectively reduced. The power controller generates a voltage control instruction according to the difference between the set power threshold and the actual power of the load, and limits the voltage control instruction through the voltage control limiter; the voltage controller generates a current control instruction according to the difference between the voltage control instruction output by the voltage control limiter and the actual output voltage of the load, and limits the current control instruction through the current control limiter; the current controller generates a drive control signal according to the difference between the current control instruction output by the current control limiter and the actual output current of the load, and limits the drive control signal through the duty cycle limiter; according to the drive control signal output by the duty cycle limiter, the duty cycle of the switch tube of the DC / AC converter is adjusted to adjust the voltage output by the DC / AC converter, thereby controlling the actual power, actual output current and actual output voltage of the load. Simply limiting the output voltage and current can easily lead to limited output power. The three-closed-loop control proposed in the present invention can dynamically enter the corresponding closed-loop control mode when the load impedance changes according to the set voltage, current and power ranges, thereby ensuring that the power supply always maintains maximum output in the safe working area within the full range of load impedance, and switching between control modes is smooth and without transition process, thereby improving the output response speed and accuracy of the high-frequency ultrasonic power supply.

[0042] In addition, the present invention also introduces a DC / DC converter, the input end of the DC / DC converter is connected to the output end of the AC / DC converter, and the output end of the DC / DC converter is connected to the input end of the DC / AC converter. The duty cycle limiter outputs a driving control signal to the DC / DC converter, and the voltage output by the DC / DC converter is adjusted by adjusting the duty cycle of the switch tube of the DC / DC converter, and the actual power, current and voltage of the load are controlled by the DC / AC converter. Directly adjusting the duty cycle of the switch tube of the DC / AC converter may cause the calculation frequency of the controller and the switching frequency of the power device to be too high, especially at high frequencies, the output of the DC / AC converter is unstable, which will cause a large power loss. The DC / DC converter controls the output voltage by adjusting the duty cycle, which can accurately control energy transmission with low loss, which can not only improve the efficiency and stability of the power supply, but also simplify the control strategy and reduce the power loss of the ultrasonic power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0044] Figure 1 It is a structural diagram of a high-frequency ultrasonic power supply.

[0045] Figure 2 It is a schematic diagram of voltage, current and power curves.

[0046] Figure 3 It is the simulated waveform of output voltage and output current when the load is 10Ω.

[0047] Figure 4 It is the simulated waveform of output voltage and output current when the load is 15Ω.

[0048] Figure 5 This is the simulated waveform of the effective value of the output current when the load is 15Ω.

[0049] Figure 6 It is the simulated waveform of output voltage and output current when the load is 80Ω.

[0050] Figure 7 This is the simulated waveform of the effective value of the output current when the load is 100Ω. DETAILED DESCRIPTION

[0051] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0052] like Figure 1 As stated, Figure 1 This is a structural diagram of a high-frequency ultrasonic power supply.

[0053] Embodiment 1 of the present invention provides a high-frequency ultrasonic power supply, including:

[0054] Power circuit, including:

[0055] An AC / DC converter, whose input end is connected to an AC power source and whose output end is connected to a DC / AC converter;

[0056] A DC / AC converter, an input end of which is connected to the AC / DC converter, and an output end of which is connected to the load;

[0057] Control loop, including:

[0058] The sampling circuit has an input end connected to the load and an output end connected to the power controller, the voltage controller, and the current controller; the sampling circuit measures the actual output voltage and the actual output current of the load and calculates the actual power of the load;

[0059] After receiving the actual power of the load output by the sampling circuit, the power controller generates a voltage control instruction based on the difference between the set power threshold and the actual power of the load;

[0060] A voltage controller limiter, whose input end is connected to the power controller to limit the voltage control command, and whose output end is connected to the voltage controller;

[0061] In this embodiment, preferably, limiting the voltage control instruction by a voltage control limiter includes:

[0062] When the voltage control instruction is greater than the maximum threshold value in the preset voltage range, the voltage control instruction is set to the maximum threshold value in the preset voltage range;

[0063] When the voltage control command is within the preset voltage range, the voltage control command remains unchanged.

[0064] After receiving the voltage control instruction output by the voltage controller limiter, the voltage controller generates a current control instruction based on the difference between the voltage control instruction and the actual output voltage of the load;

[0065] A current controller limiter, whose input end is connected to the voltage controller to limit the current control instruction, and whose output end is connected to the current controller;

[0066] In this embodiment, preferably, limiting the current control instruction by a current control limiter includes:

[0067] When the current control instruction is greater than the maximum threshold value in the preset current range, the current control instruction is set to be the maximum threshold value in the preset current range;

[0068] When the current control command is within the preset current range, the current control command remains unchanged.

[0069] After receiving the current control instruction output by the current controller limiter, the current controller generates a drive control signal based on the difference between the current control instruction and the actual output current of the load;

[0070] The duty cycle limiter has an input end connected to the current controller to limit the drive control signal, and an output end is used to output the drive control signal to the DC / AC converter. By adjusting the duty cycle of the switch tube of the DC / AC converter, the voltage output by the DC / AC converter is adjusted, thereby controlling the actual power, actual output current and actual output voltage of the load.

[0071] In this embodiment, preferably, limiting the driving control signal by a duty cycle limiter includes:

[0072] When the driving control signal is greater than the maximum threshold value in the preset duty cycle range, the driving control signal is set to the maximum threshold value in the preset duty cycle range;

[0073] When the driving control signal is within the preset duty cycle range, the driving control signal remains unchanged.

[0074] In this embodiment, specifically, the preset duty cycle range is [0, 0.5].

[0075] In this embodiment, preferably, the power circuit further includes:

[0076] The DC / DC converter has an input end connected to the AC / DC converter output end, and an output end connected to the DC / AC converter input end.

[0077] In this embodiment, preferably, the duty cycle limiter has its input end connected to the current controller to limit the drive control signal, and its output end is used to output the drive control signal to the DC / DC converter, and the voltage output by the DC / DC converter is adjusted by adjusting the duty cycle of the switch tube of the DC / DC converter, so as to control the actual power, current and voltage of the load through the DC / AC converter.

[0078] The present invention introduces a DC / DC converter, wherein the input end of the DC / DC converter is connected to the output end of the AC / DC converter, and the output end of the DC / DC converter is connected to the input end of the DC / AC converter. A duty cycle limiter outputs a driving control signal to the DC / DC converter, and the voltage output by the DC / DC converter is adjusted by adjusting the duty cycle of the switch tube of the DC / DC converter, and the actual power, current and voltage of the load are controlled by the DC / AC converter. Directly adjusting the duty cycle of the switch tube of the DC / AC converter may cause the output of the DC / AC converter to be unstable, resulting in a large power loss, especially at high frequencies. The DC / DC converter controls the output voltage by adjusting the duty cycle, and can accurately control energy transmission with low loss, which can not only improve the efficiency and stability of the power supply, but also simplify the control strategy and reduce the power loss of the ultrasonic power supply.

[0079] Embodiment 2 of the present invention provides a method for controlling a high-frequency ultrasonic power supply, including:

[0080] The actual output voltage and the actual output current of the load are measured by a sampling circuit connected to the load, and the actual power of the load is calculated;

[0081] Calculate the difference between the set power threshold and the actual power of the load. The power controller generates a voltage control instruction according to the difference between the set power threshold and the actual power of the load, and limits the voltage control instruction through the voltage control limiter.

[0082] The voltage controller generates a current control command based on the difference between the voltage control command output by the voltage control limiter and the actual output voltage of the load, and limits the current control command through the current control limiter.

[0083] The difference between the current control command output by the current control limiter and the actual output current of the load is calculated, and the current controller generates a drive control signal according to the difference between the current control command output by the current control limiter and the actual output current of the load, and limits the drive control signal through the duty cycle limiter;

[0084] According to the driving control signal output by the duty cycle limiter, the duty cycle of the switch tube of the DC / AC converter is adjusted to adjust the voltage output by the DC / AC converter, thereby controlling the actual power, actual output current and actual output voltage of the load.

[0085] like Figure 2 As shown, Figure 2The figure is a schematic diagram of the voltage, current and power curves. The present invention divides the changing load impedance into three different intervals according to the corresponding safe working area, namely the constant current area, the constant power area, and the constant voltage area. The control algorithm enables the ultrasonic power supply to always meet the control requirements of voltage, current, and power during its operation when the load impedance changes over a large range, and is finally verified on the simulation and experimental platform.

[0086] When the load impedance is greater than 0 and less than or equal to R1, as the load impedance increases, the current closed loop is entered, and the controller controls the actual output current of the load to be the set current threshold. At this time, the current controller is in an unsaturated state, and the voltage controller and the power controller are in a saturated state; wherein, To set the power threshold, is the maximum threshold in the preset current range.

[0087] When the load impedance is greater than R1 and less than or equal to R2, as the load impedance increases, the power closed loop is entered, and the actual power of the load controlled by the controller is the set power threshold. At this time, the power controller is in an unsaturated state, and the current controller and the voltage controller are in a saturated state; wherein, To set the power threshold, is the maximum threshold in the preset current range, is the maximum threshold in the preset voltage range.

[0088] When the load impedance is greater than R2, as the load impedance increases, the voltage closed loop is entered, and the actual output voltage of the load controlled by the controller is the set voltage threshold. At this time, the voltage controller is in an unsaturated state, and the current controller and the power controller are in a saturated state; wherein, To set the power threshold, is the maximum threshold in the preset voltage range.

[0089] As shown in Table 1, Table 1 shows the load impedance and its corresponding closed-loop state.

[0090] Table 1

[0091]

[0092] The three-closed-loop control proposed in the present invention can dynamically enter the corresponding closed-loop control mode when the load impedance changes according to the set voltage, current and power ranges, thereby ensuring that the power supply always maintains the maximum output in the safe working area within the full range of load impedance, and switching between control modes is smooth and without transition process, thereby improving the output response speed and accuracy of the high-frequency ultrasonic power supply.

[0093] The third embodiment of the present invention simulates a high-frequency ultrasonic power supply proposed in the first embodiment, as shown in Table 2. Table 2 is a list of simulation and experimental parameters provided in the third embodiment.

[0094] Table 2

[0095]

[0096] Where U is the actual output voltage of the load and f is the output frequency of the DC / AC converter.

[0097] like Figure 3 As shown, Figure 3 The simulated waveforms of the output voltage and output current when the load is 10Ω are shown in Figure 2. Figure 4 As shown, Figure 4 The simulated waveforms of the output voltage and output current when the load is 15Ω are shown in Figure 1. Figure 3 , 4 It can be seen that the output voltage and output current are relatively stable when the load is 10Ω and 15Ω. Figure 5 The simulated waveform of the effective value of the output current when the load is 15Ω is 3A after reaching stability. When the load is 15Ω, the effective value of the output voltage is 45V and the output power is 135W, which meets the requirements of the output curve. Figure 6 As shown, Figure 6 It is the simulated waveform of output voltage and output current when the load is 80Ω. 80Ω is the turning point from constant power area to constant voltage area, and its power is still stable at 135W. At this time, it enters the voltage closed loop and the voltage gradually stabilizes. When the load impedance increases to 80Ω, although the system enters the voltage closed loop, the power is still maintained at 135W, which satisfies the smooth transition from constant power area to constant voltage area and ensures the continuity and stability of energy. Figure 7 As shown, Figure 7 The following are the simulated waveforms of the output voltage and output current when the load is 100Ω. After simulation and measurement, the output voltage is basically stable at 104V and the current is also 1.039A, which fully verifies the stability and control accuracy of the system in the constant voltage area.

[0098] The above simulation fully demonstrates that under different load conditions, the voltage and current of the present invention can remain relatively stable, thus avoiding the voltage and current instability caused by load fluctuations.

[0099] Embodiment 4 of the present invention provides a high-frequency ultrasonic device, including:

[0100] A high frequency ultrasonic power supply as described above;

[0101] The ultrasonic transducer has an input end connected to the output end of the DC / AC converter, and an output end connected to the input end of the control loop.

[0102] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0103] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0104] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0105] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0106] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A high-frequency ultrasonic power supply, characterized in that: include: Power circuit, including: An AC / DC converter, whose input end is connected to an AC power source and whose output end is connected to a DC / AC converter; A DC / AC converter, an input end of which is connected to the AC / DC converter, and an output end of which is connected to the load; Control loop, including: The sampling circuit has an input end connected to the load and an output end connected to the power controller, the voltage controller, and the current controller; the sampling circuit measures the actual output voltage and the actual output current of the load and calculates the actual power of the load; After receiving the actual power of the load output by the sampling circuit, the power controller generates a voltage control instruction based on the difference between the set power threshold and the actual power of the load; A voltage controller limiter, whose input end is connected to the power controller to limit the voltage control command, and whose output end is connected to the voltage controller; After receiving the voltage control instruction output by the voltage controller limiter, the voltage controller generates a current control instruction based on the difference between the voltage control instruction and the actual output voltage of the load; A current controller limiter, whose input end is connected to the voltage controller to limit the current control instruction, and whose output end is connected to the current controller; After receiving the current control instruction output by the current controller limiter, the current controller generates a drive control signal based on the difference between the current control instruction and the actual output current of the load; The duty cycle limiter has an input end connected to the current controller to limit the drive control signal, and an output end is used to output the drive control signal to the DC / AC converter. By adjusting the duty cycle of the switch tube of the DC / AC converter, the voltage output by the DC / AC converter is adjusted, thereby controlling the actual power, actual output current and actual output voltage of the load.

2. A high-frequency ultrasonic power supply according to claim 1, characterized in that: The power circuit also includes: The DC / DC converter has an input end connected to the AC / DC converter output end, and an output end connected to the DC / AC converter input end.

3. A high-frequency ultrasonic power supply according to claim 2, characterized in that: The duty cycle limiter has an input end connected to the current controller to limit the drive control signal, and an output end is used to output the drive control signal to the DC / DC converter. By adjusting the duty cycle of the switch tube of the DC / DC converter, the voltage output by the DC / DC converter is adjusted, and the actual power, current and voltage of the load are controlled through the DC / AC converter.

4. A high-frequency ultrasonic power supply according to claim 1, characterized in that: The voltage control command is limited by the voltage control limiter, including: When the voltage control instruction is greater than the maximum threshold value in the preset voltage range, the voltage control instruction is set to the maximum threshold value in the preset voltage range; When the voltage control command is within the preset voltage range, the voltage control command remains unchanged.

5. A high-frequency ultrasonic power supply according to claim 1, characterized in that: The current control command is limited by the current control limiter, including: When the current control instruction is greater than the maximum threshold value in the preset current range, the current control instruction is set to be the maximum threshold value in the preset current range; When the current control command is within the preset current range, the current control command remains unchanged.

6. A high-frequency ultrasonic power supply according to claim 1, characterized in that: The drive control signal is limited by the duty cycle limiter, including: When the driving control signal is greater than the maximum threshold value in the preset duty cycle range, the driving control signal is set to the maximum threshold value in the preset duty cycle range; When the driving control signal is within the preset duty cycle range, the driving control signal remains unchanged.

7. A high-frequency ultrasonic power supply according to claim 6, characterized in that: The preset duty cycle range is [0, 0.5].

8. A method for controlling a high-frequency ultrasonic power supply, characterized in that: include: The actual output voltage and the actual output current of the load are measured by a sampling circuit connected to the load, and the actual power of the load is calculated; Calculate the difference between the set power threshold and the actual power of the load. The power controller generates a voltage control instruction according to the difference between the set power threshold and the actual power of the load, and limits the voltage control instruction through the voltage control limiter. The voltage controller generates a current control command based on the difference between the voltage control command output by the voltage control limiter and the actual output voltage of the load, and limits the current control command through the current control limiter. The difference between the current control command output by the current control limiter and the actual output current of the load is calculated, and the current controller generates a drive control signal according to the difference between the current control command output by the current control limiter and the actual output current of the load, and limits the drive control signal through the duty cycle limiter; According to the driving control signal output by the duty cycle limiter, the duty cycle of the switch tube of the DC / AC converter is adjusted to adjust the voltage output by the DC / AC converter, thereby controlling the actual power, actual output current and actual output voltage of the load.

9. A high-frequency ultrasonic device, characterized in that: include: A high-frequency ultrasonic power supply according to any one of claims 1 to 9; The ultrasonic transducer has an input end connected to the output end of the DC / AC converter, and an output end connected to the input end of the control loop.

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