Output control method and device of intermediate-frequency power supply, storage medium and computer equipment

Abstract

The invention discloses an output control method and device of an intermediate-frequency power supply, a storage medium and computer equipment, and relates to the technical field of intermediate-frequency power supplies. The method comprises the following steps: determining an alternating current output by an inverter of a medium-frequency power supply in real time, and determining an active current component and a reactive current component of the alternating current; obtaining a target output current, determining an active current target value and a reactive current target value of the target output current, determining a first error value between the active current target value and the active current component, and determining a second error value between the reactive current target value and the reactive current component; performing proportional-integral adjustment on the first error value and the second error value to obtain a modulation signal, and generating a pulse width modulation signal based on the modulation signal; and on-off control is performed on a switching tube in a bridge type inverter circuit of the inverter based on the pulse width modulation signal so as to adjust the alternating current output by the inverter. The method can improve the control precision of the output current of the medium-frequency power supply.

Description

Technical Field

[0001] This invention relates to the field of intermediate frequency power supply technology, and in particular to an output control method, device, storage medium, and computer equipment for an intermediate frequency power supply. Background Technology

[0002] Currently, medium-frequency power supplies are widely used in the field of metal smelting, especially playing a key role in aluminum production. Their core function is to convert industrial frequency (50 / 60Hz) AC or DC power into medium-frequency AC power with frequencies ranging from several hundred hertz to tens of kilohertz, outputting a stable medium-frequency current to meet the needs of processes such as induction heating and electromagnetic stirring.

[0003] However, in actual production processes, high-precision real-time control of the output current of the intermediate frequency power supply is required to ensure process stability. Existing control methods mostly employ open-loop or fixed-duty-cycle pulse width modulation (PWM) strategies. This involves sending a PWM signal with a preset duty cycle to the inverter's switching transistors to control their on / off state, thereby stabilizing the output current of the intermediate frequency power supply at a specific value. However, these methods lack real-time feedback regulation of the output current. When the grid voltage fluctuates or the load changes, the PWM signal cannot be adjusted in a timely manner, leading to instability in the output current of the intermediate frequency power supply. This inability to accurately control the output current affects the stability of the melting process and can even cause product quality degradation or equipment malfunctions. Summary of the Invention

[0004] In view of this, this application provides an output control method, device, storage medium and computer equipment for intermediate frequency power supplies, the main purpose of which is to solve the technical problem of weak control accuracy of the output current of intermediate frequency power supplies.

[0005] According to a first aspect of the present invention, an output control method for a medium-frequency power supply is provided for controlling the output current of an inverter of the medium-frequency power supply, the method comprising: The AC current output by the inverter of the intermediate frequency power supply is determined in real time, and the active current component and reactive current component of the AC current are determined. Obtain a preset target output current, determine the active current target value and reactive current target value of the target output current, determine the first error value between the active current target value and the active current component, and determine the second error value between the reactive current target value and the reactive current component. A modulation signal is obtained by performing proportional-integral adjustment on the first error value and the second error value, and a pulse width modulation signal is generated based on the modulation signal; The switching transistors in the bridge inverter circuit of the inverter are controlled to turn on and off based on the pulse width modulation signal, so as to adjust the AC current output by the inverter so that the AC current approaches the target output current.

[0006] In an optional embodiment, the intermediate frequency power supply is an intermediate frequency power supply that outputs three-phase alternating current; the alternating current includes phase A alternating current, phase B alternating current, and phase C alternating current; determining the active current component and reactive current component of the alternating current includes: performing αβ transformation on the phase A alternating current, the phase B alternating current, and the phase C alternating current to obtain α current component and β current component, and determining the instantaneous phase angle of the alternating current voltage output by the inverter of the intermediate frequency power supply; based on the instantaneous phase angle, performing dq transformation on the α current component and the β current component to obtain the active current component and reactive current component.

[0007] In an optional embodiment, the step of performing proportional-integral adjustment on the first error value and the second error value to obtain a modulation signal, and generating a pulse width modulation signal based on the modulation signal, includes: performing proportional-integral adjustment on the first error value to obtain a d-axis voltage command signal; performing proportional-integral adjustment on the second error value to obtain a q-axis voltage command signal; performing inverse Park transform on the d-axis voltage command signal and the q-axis voltage command signal to obtain an α-axis voltage command signal and a β-axis voltage command signal; and performing space vector modulation on the α-axis voltage command signal and the β-axis voltage command signal to obtain the pulse width modulation signal.

[0008] In an optional embodiment, the intermediate frequency power supply is an intermediate frequency power supply that outputs single-phase AC power; the step of determining the AC current output by the inverter of the intermediate frequency power supply in real time, and determining the active current component and reactive current component of the AC current, includes: acquiring the AC current output by the inverter, and delaying the phase of the AC current by 90 degrees to obtain an orthogonal AC current; determining the instantaneous phase angle of the AC voltage output by the inverter of the intermediate frequency power supply, and performing dq transformation on the AC current and the orthogonal AC current based on the instantaneous phase angle to obtain the active current component and reactive current component.

[0009] In an optional embodiment, the step of controlling the switching transistors in the bridge inverter circuit of the inverter based on the pulse width modulation signal to adjust the AC current output by the inverter includes: acquiring each rising edge of the pulse width modulation signal and delaying the rising edge by a preset time to generate a first pulse width modulation signal; acquiring each falling edge of the pulse width modulation signal and delaying the falling edge by the preset time to generate a second pulse width modulation signal, and inverting the second pulse width modulation signal to obtain a third pulse width modulation signal; controlling the switching transistors of the upper arm of the bridge inverter circuit to turn on and off through the first pulse width modulation signal, and controlling the switching transistors of the lower arm of the bridge inverter circuit to turn on and off through the third pulse width modulation signal.

[0010] In an optional embodiment, the step of performing proportional-integral (PI) adjustment on the first error value and the second error value to obtain a modulation signal includes: obtaining a preset proportional gain and integral gain required for the PI adjustment; determining an error energy value based on the first error value and the second error value, and determining whether the error energy value is within a preset energy range; when the error energy value exceeds the energy range, increasing the proportional gain of the PI adjustment, and performing PI adjustment on the first error value and the second error value respectively to obtain a modulation signal; when the error energy value is less than the energy range, decreasing the integral gain of the PI adjustment, and performing PI adjustment on the first error value and the second error value respectively to obtain a modulation signal.

[0011] In an optional embodiment, increasing the proportional gain of the proportional-integral adjustment includes: The method involves determining whether the proportional gain is higher than a preset upper limit value. If the proportional gain is not higher than the upper limit value, the proportional gain is multiplied by a preset first coefficient to obtain an improved proportional gain, wherein the first coefficient is greater than one. The method of reducing the integral gain of the proportional-integral adjustment includes determining whether the integral gain is lower than a preset lower limit value. If the integral gain is lower than the lower limit value, the integral gain is multiplied by a preset second coefficient to obtain a reduced integral gain, wherein the second coefficient is less than one.

[0012] According to a second aspect of the present invention, an output control device for an intermediate frequency power supply is provided, the device comprising: The current processing module is used to determine the AC current output by the inverter of the intermediate frequency power supply in real time, and to determine the active current component and reactive current component of the AC current. An error identification module is used to acquire a preset target output current, determine the active current target value and reactive current target value of the target output current, determine a first error value between the active current target value and the active current component, and determine a second error value between the reactive current target value and the reactive current component. The signal generation module is used to perform proportional-integral adjustment on the first error value and the second error value to obtain a modulation signal, and generate a pulse width modulation signal based on the modulation signal; The output control module is used to control the switching transistors in the bridge inverter circuit of the inverter based on the pulse width modulation signal, so as to adjust the AC current output by the inverter so that the AC current approaches the target output current.

[0013] According to a third aspect of the present invention, a storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the above-described intermediate frequency power supply output control method.

[0014] According to a fourth aspect of the present invention, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the above-described intermediate frequency power supply output control method.

[0015] This invention provides an output control method, device, storage medium, and computer equipment for a medium-frequency power supply. It detects the AC current output by the inverter in the medium-frequency power supply in real time, determines its active and reactive current components, and applies proportional-integral (PI) modulation to the first error value between the active current component and the target active current value calculated based on the target current value, and the second error value between the reactive current component and the target reactive current value, respectively. This generates corresponding modulation signals, which in turn generate a PWM signal, forming a closed-loop feedback control. Compared to existing open-loop or fixed duty cycle control methods, this invention can respond in real time to grid voltage fluctuations or load changes, dynamically adjusting the duty cycle of the PWM signal, effectively improving the stability and control accuracy of the output current. This not only ensures the continuity and process stability of the smelting process but also significantly improves product quality and production safety.

[0016] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 A flowchart illustrating an output control method for a medium-frequency power supply provided in an embodiment of the present invention is shown. Figure 2 A schematic diagram of an inverter provided in an embodiment of the present invention is shown; Figure 3 A schematic diagram of another inverter provided in an embodiment of the present invention is shown; Figure 4 A schematic diagram of the structure of an output control device for a medium-frequency power supply provided in an embodiment of the present invention is shown. Detailed Implementation

[0018] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the present application can be combined with each other.

[0019] Currently, in actual production processes, high-precision real-time control of the output current of intermediate frequency power supplies is required to ensure process stability. Existing control methods mostly employ open-loop or fixed duty cycle pulse width modulation (PWM) strategies. This involves sending a PWM signal with a preset duty cycle to the inverter's switching transistors to control their on / off state, thereby stabilizing the output current of the intermediate frequency power supply at a specific value. However, these methods lack real-time feedback adjustment of the output current. When the grid voltage fluctuates or the load changes, the PWM signal cannot be adjusted in a timely manner, leading to instability in the output current of the intermediate frequency power supply. This inability to accurately control the output current affects the stability of the melting process and can even cause product quality degradation or equipment malfunction.

[0020] To address the above problems, in one embodiment, such as Figure 1 As shown, an output control method for a medium-frequency power supply is provided. Taking a computer device that controls the output current of an inverter of a medium-frequency power supply as an example, the method includes the following steps: 101. Determine the AC current output by the inverter of the intermediate frequency power supply in real time, and determine the active current component and reactive current component of the AC current.

[0021] Among them, the inverter of the medium frequency power supply can be such as Figure 2 The inverter shown, which outputs three-phase alternating current, can also be as follows: Figure 3 The inverter shown outputs single-phase AC current.

[0022] Here, as Figure 2As shown, if the inverter of the intermediate frequency power supply is an inverter that outputs three-phase AC current, the A-phase AC current, B-phase AC current and C-phase AC current output by the inverter can be collected based on current sensors or current transformers.

[0023] Specifically, firstly, the A-phase AC current, the B-phase AC current, and the C-phase AC current can be transformed using an αβ transformation to obtain the α-current components and β-current components of the three-phase AC current in the αβ coordinate system. The αβ transformation, also known as the Clarke transformation, is a mathematical tool used to convert current or voltage in a three-phase stationary coordinate system (ABC coordinate system) into a two-phase stationary coordinate system (αβ coordinate system). Its core purpose is to simplify the analysis process of three-phase systems.

[0024] Here, the α-current component and the β-current component can be calculated by performing α-β transformation based on Equations 1 and 2: (1) (2) in, For the α current component, For the β current component, For phase A alternating current, This is the phase B alternating current. This represents the C-phase alternating current. Here, it can also be approximated as... Determined as .

[0025] Furthermore, the instantaneous phase angle of the AC voltage output by the inverter of the intermediate frequency power supply is determined. Here, the current AC voltage output by the inverter can be acquired, and the instantaneous phase angle of the AC voltage can be determined based on the phase-locked loop (PLL). Further, based on the instantaneous phase angle, the α current component and the β current component are subjected to dq transformation to obtain the active current component and reactive current component of the AC current in the rotating coordinate system (dq coordinate system).

[0026] The dq transformation, also known as the Park transformation, is used to convert from a two-phase stationary coordinate system (αβ coordinate system) to a two-phase rotating coordinate system (dq coordinate system). Specifically, the active and reactive current components can be calculated based on formulas 3 and 4: cos + sin (3) sin + cos (4) in, For the α current component, For the β current component, The instantaneous phase angle of the AC voltage. For active current components, This represents the reactive current component.

[0027] Furthermore, such as Figure 3 As shown, if the inverter of the intermediate frequency power supply is an inverter that outputs single-phase AC current, the instantaneous value of the AC current output by the inverter can be collected based on the current sensor or the current transformer, and the phase of the collected AC current is delayed by 90 degrees, that is, the phase of the AC current is delayed by 1 / 4 cycle to obtain the quadrature AC current.

[0028] Furthermore, the instantaneous phase angle of the AC voltage output by the inverter of the intermediate frequency power supply at the current moment is determined. Based on the instantaneous phase angle, the AC current and the orthogonal AC current are subjected to dq transformation to obtain the active current component and the reactive current component.

[0029] Here, the active current component and reactive current component can be calculated based on formulas 5 and 6: cos + sin (5) sin + cos (6) in, For alternating current, It is an orthogonal alternating current. The instantaneous phase angle of the AC voltage. For active current components, This represents the reactive current component.

[0030] 102. Obtain a preset target output current, determine the active current target value and reactive current target value of the target output current, determine the first error value between the active current target value and the active current component, and determine the second error value between the reactive current target value and the reactive current component.

[0031] Here, the target output current can be the effective value of the output current required by the aluminum manufacturing process, that is, the current value that the inverter of the intermediate frequency power supply needs to stably output. This target output current value is then multiplied by... The active current target value can be obtained; here, the value of the active current target value can also be preset; furthermore, the reactive current target value can be set to zero. Further, the active current component is subtracted from the active current target value to obtain the first error value, and the reactive current component is subtracted from the reactive current target value to obtain the second error value.

[0032] 103. The first error value and the second error value are proportionally and integrally adjusted to obtain a modulation signal, and a pulse width modulation signal is generated based on the modulation signal.

[0033] Specifically, the first error value can be proportionally and integrally adjusted to obtain the d-axis voltage command signal, and the second error value can be proportionally and integrally adjusted to obtain the q-axis voltage command signal.

[0034] Here, the logic for proportional-integral adjustment of the first error value is shown in Equation 7: (7) in, This is the d-axis voltage command signal. The preset proportional gain, The preset integral gain, The first error value is given, and t is the time point of the current control cycle in proportional-integral regulation.

[0035] Furthermore, the logic for proportional-integral adjustment of the second error value is shown in Equation 8: (8) in, This is the q-axis voltage command signal. The preset proportional gain, The preset integral gain, The second error value is given, and t is the time point of the current control cycle in proportional-integral regulation.

[0036] Then, the d-axis voltage command signal and the q-axis voltage command signal are subjected to inverse Park transform to obtain the α-axis voltage command signal and the β-axis voltage command signal in the two-phase stationary coordinate system as modulation signals. The α-axis voltage command signal and the β-axis voltage command signal are key intermediate variables for PWM signal modulation; here, the α-axis voltage command signal and the β-axis voltage command signal can be calculated based on Equation 9: = (9) in, This is the α-axis voltage command signal. This is the β-axis voltage command signal. The instantaneous phase angle of the AC voltage. This is the d-axis voltage command signal. This is the q-axis voltage command signal.

[0037] Finally, the α-axis voltage command signal and the β-axis voltage command signal are subjected to space vector modulation to obtain a pulse width modulation signal.

[0038] Here, the α-axis voltage command signal and the β-axis voltage command signal can be adjusted using space vector PWM or sinusoidal PWM to obtain a pulse width modulation signal. Specifically, firstly, a voltage vector can be synthesized based on the α-axis and β-axis voltage command signals, treating the two signals as vector representations in the αβ coordinate system. Then, the angle and amplitude of the voltage vector are calculated to determine which sector in the hexagonal space vector modulation diagram in the αβ coordinate system it belongs to. Next, based on the sector where the voltage vector is located, the target vector is approximated using adjacent basic voltage vectors and the zero vector (or intermediate vector), and the corresponding action time is allocated within each switching cycle to obtain the pulse width modulation signal. Here, for a three-phase inverter, the corresponding PWM signal is generated by calculating the high-level action time corresponding to the three bridge arms and writing it into the PWM module. For a single-phase inverter, usually only the voltage command signals of two phases need to be considered and converted into complementary PWM signals for the upper and lower bridge arms of the H-bridge.

[0039] 104. Based on the pulse width modulation signal, control the switching transistors in the bridge inverter circuit of the inverter to adjust the AC current output by the inverter so that the AC current approaches the target output current.

[0040] Specifically, if the inverter is as follows Figure 2 The three-phase inverter shown can invert the pulse width modulation (PWM) signal to obtain an inverted PWM signal, which is then input to the gate of the first switch L1 and the inverted PWM signal to the gate of the fourth switch L4. Further, the phase of the PWM signal is delayed by 120 degrees and input to the gate of the second switch L2; the phase of the inverted PWM signal is delayed by 120 degrees and input to the gate of the fifth switch L5. Further, the phase of the PWM signal is delayed by 240 degrees and input to the gate of the third switch L3; the phase of the inverted PWM signal is delayed by 240 degrees and input to the gate of the sixth switch L6, thereby adjusting the AC output from phase A, phase B, and phase C of the three-phase inverter.

[0041] Furthermore, if the inverter is as follows Figure 3The single-phase inverter shown can invert the pulse width modulation (PWM) signal to obtain an inverted PWM signal. This inverted PWM signal is then input to the gates of the seventh switch L7 and the tenth switch L10, and the inverted PWM signal is input to the gates of the eighth switch L8 and the ninth switch L9, respectively, to adjust the AC output from the first output terminal 100 and the second output terminal 200 of the single-phase inverter. The intermediate frequency power supply output control method provided in this embodiment detects the output AC current in real time and extracts its active and reactive current components. It calculates the error by combining preset active and reactive current target values, generates a modulation signal through proportional-integral regulation, and converts it into a PWM signal, thus achieving closed-loop control of the inverter switches. Compared to existing open-loop control methods, this invention can dynamically respond to grid fluctuations and load changes, adjust the output current in real time, significantly improve the accuracy and stability of current control, ensure that the intermediate frequency power supply output current quickly approaches the target value, effectively guarantee the continuity of the smelting process and product quality, and improve the system's anti-interference capability and operational reliability.

[0042] In an optional embodiment, the method of controlling the on / off switching of the switching transistors in the bridge inverter circuit of the inverter based on the pulse width modulation signal to adjust the AC current output by the inverter includes: First, each rising edge in the pulse width modulation signal is acquired, and the rising edge is delayed by a preset time to generate a first pulse width modulation signal. The preset time can be tens of nanoseconds (ns) or a few microseconds (μs), and its specific length can be determined according to the actual situation. Specifically, each rising edge in the pulse width modulation signal is determined, and the time of occurrence of each rising edge in the signal is delayed by a preset time, so that the occurrence of each rising edge in the PWM signal is delayed by the preset time length, while each falling edge in the PWM signal remains unchanged, to obtain the first pulse width modulation signal.

[0043] Then, each falling edge in the pulse width modulation (PWM) signal is acquired, and the falling edge is delayed by the preset time to generate a second PWM signal. The second PWM signal is then inverted to obtain a third PWM signal. Specifically, each falling edge in the PWM signal is determined, and the falling edge is delayed in the signal by the preset time to postpone the occurrence of each falling edge in the PWM signal by the preset time length, while keeping each rising edge in the PWM signal unchanged, thus obtaining the second PWM signal. Further, the second PWM signal is inverted to obtain the inverted third PWM signal.

[0044] Finally, the switching transistors of the upper arm of the bridge inverter circuit are controlled to turn on and off by the first pulse width modulation signal, and the switching transistors of the lower arm of the bridge inverter circuit are controlled to turn on and off by the third pulse width modulation signal.

[0045] Here, if the inverter is as follows Figure 2 The three-phase inverter shown can input a first pulse width modulation signal to the gate of the first switch L1; delay the phase of the first pulse width modulation signal by 120 degrees and input it to the gate of the second switch L2; delay the phase of the first pulse width modulation signal by 240 degrees and input it to the gate of the third switch L3; so that the phase difference between the signal received at the gate of the first switch L1 and the signal received at the gate of the second switch L2 is 120 degrees, and the phase difference between the signal received at the gate of the second switch L2 and the signal received at the gate of the third switch L3 is 120 degrees. Furthermore, the third pulse width modulation signal is input to the gate of the fourth switch L4; the phase of the third pulse width modulation signal is delayed by 120 degrees and input to the gate of the fifth switch L5; the phase of the third pulse width modulation signal is delayed by 240 degrees and input to the gate of the sixth switch L6; so that the phase difference between the signal received at the gate of the fourth switch L4 and the signal received at the gate of the fifth switch L5 is 120 degrees, and the phase difference between the signal received at the gate of the fifth switch L5 and the signal received at the gate of the sixth switch L6 is 120 degrees.

[0046] Here, if the inverter is as follows Figure 3 The single-phase inverter shown can input the first pulse width modulation signal to the gate of the seventh switch L7 and the gate of the tenth switch L10, and input the third pulse width modulation signal to the gate of the eighth switch L8 and the gate of the ninth switch L9. The embodiment provided in this application effectively introduces dead time by delaying the rising and falling edges of the PWM signal and generating complementary drive signals, preventing shoot-through short circuits in the upper and lower bridge arm switches of the bridge inverter circuit, and reducing the risk of device damage due to short circuits.

[0047] In an optional embodiment, the method of obtaining the modulated signal by proportional-integral adjustment of the first error value and the second error value includes: first, obtaining a preset proportional gain and integral gain required in the proportional-integral adjustment process.

[0048] Then, based on the first error value and the second error value, an error energy value is determined, and it is determined whether the error energy value is within a preset energy range; wherein, the energy range is used to determine whether the error energy value is too large or too small, and its numerical range can be determined according to the actual situation.

[0049] Specifically, the error energy value can be calculated using formula 10: E= (10) Where E is the error energy value. This is the first error value. This is the second error value.

[0050] Then, when the error energy value exceeds the energy range, the proportional gain of the proportional-integral adjustment is increased, and proportional-integral adjustment is performed on the first error value and the second error value respectively to obtain the modulation signal; Specifically, when the error energy value exceeds the energy range, the proportional gain in Formulas 7 and 8 can be increased. The modulation signal is obtained by proportional-integral adjustment of the first error value and the second error value based on the adjusted proportional gain.

[0051] To prevent the proportional gain from becoming too high after multiple adjustments, the proportional gain is checked against a preset upper limit before adjustment. If the proportional gain is below the upper limit, it is multiplied by a preset first coefficient to obtain the increased proportional gain. This first coefficient is greater than one and can be between 1.1 and 1.5. If the proportional gain exceeds the upper limit, no adjustment is made.

[0052] Furthermore, when the error energy value is less than the energy range, the integral gain of the proportional-integral adjustment is reduced, and proportional-integral adjustment is performed on the first error value and the second error value respectively to obtain the modulation signal.

[0053] Specifically, when the error energy value is less than the energy range, the integral gain in Equations 7 and 8 can be reduced. The modulation signal is obtained by proportional-integral adjustment of the first error value and the second error value based on the adjusted integral gain.

[0054] To prevent the integral gain from becoming too low after multiple adjustments, when adjusting the proportional gain, it can be determined whether the integral gain is lower than a preset lower limit. If the integral gain is lower than the lower limit, the integral gain is multiplied by a preset second coefficient to obtain the reduced integral gain. This second coefficient is less than one and can be between 0.9 and 1.0. If the integral gain is lower than the lower limit, no adjustment is made to the proportional gain.

[0055] The embodiments provided in this application can adjust the proportional and integral gains in real time according to the system operating status, effectively coping with load changes and power grid fluctuations. Compared with fixed-parameter PI control, this method significantly improves the dynamic response speed and stability of the current loop, suppresses overshoot, and accelerates the adjustment process. In complex environments with time-varying parameters in medium-frequency power supplies, it can maintain excellent control performance, improve output current accuracy and system robustness, enhance anti-interference capabilities, and ensure continuous and stable smelting processes.

[0056] The intermediate frequency power supply output control method provided in this embodiment improves the dynamic response performance of the intermediate frequency power supply by highly precise adjustment of the output current, extracting active and reactive current components using Clarke and Park transforms, and generating a PWM signal through PI regulation. Furthermore, the form of the PWM signal is adjusted to prevent bridge arm shoot-through, enhancing system safety. Simultaneously, an adaptive PI parameter adjustment strategy is employed to adjust the gain online based on error energy, balancing response speed and stability. This method is suitable for smelting conditions with large load fluctuations, significantly improving the accuracy and reliability of the output current and ensuring continuous and stable operation of the production process.

[0057] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. In addition, the labels corresponding to each step in the above embodiments are only for identification purposes and are not intended to limit the execution order of the steps. The execution order of the steps in each embodiment can be set according to the actual situation.

[0058] Furthermore, as Figure 1 The specific implementation of the method shown in this embodiment provides an output control device for a medium-frequency power supply, such as... Figure 4 As shown, the device includes: a current processing module 41, an error identification module 42, a signal generation module 43, and an output control module 44.

[0059] The current processing module 41 can be used to determine the AC current output by the inverter of the intermediate frequency power supply in real time, and to determine the active current component and reactive current component of the AC current. The error identification module 42 can be used to obtain a preset target output current, determine the active current target value and reactive current target value of the target output current, determine the first error value between the active current target value and the active current component, and determine the second error value between the reactive current target value and the reactive current component. The signal generation module 43 can be used to perform proportional-integral adjustment on the first error value and the second error value to obtain a modulation signal, and generate a pulse width modulation signal based on the modulation signal; The output control module 44 can be used to control the switching transistors in the bridge inverter circuit of the inverter based on the pulse width modulation signal, so as to adjust the AC current output by the inverter so that the AC current approaches the target output current.

[0060] In a specific application scenario, the intermediate frequency power supply is an intermediate frequency power supply that outputs three-phase AC power; the current processing module 41 can be used to perform αβ transformation on the A-phase AC current, the B-phase AC current, and the C-phase AC current to obtain the α current component and the β current component, and determine the instantaneous phase angle of the AC voltage output by the inverter of the intermediate frequency power supply; based on the instantaneous phase angle, the α current component and the β current component are subjected to dq transformation to obtain the active current component and the reactive current component.

[0061] In a specific application scenario, the intermediate frequency power supply is an intermediate frequency power supply that outputs single-phase AC power. The current processing module 41 can be used to obtain the AC current output by the inverter and delay the phase of the AC current by 90 degrees to obtain the orthogonal AC current; determine the instantaneous phase angle of the AC voltage output by the inverter of the intermediate frequency power supply; and perform dq transformation on the AC current and the orthogonal AC current based on the instantaneous phase angle to obtain the active current component and the reactive current component.

[0062] In a specific application scenario, the signal generation module 43 can be used to perform proportional-integral adjustment on the first error value to obtain a d-axis voltage command signal, perform proportional-integral adjustment on the second error value to obtain a q-axis voltage command signal, perform inverse Park transform on the d-axis voltage command signal and the q-axis voltage command signal to obtain an α-axis voltage command signal and a β-axis voltage command signal, and perform space vector modulation on the α-axis voltage command signal and the β-axis voltage command signal to obtain the pulse width modulation signal.

[0063] In a specific application scenario, the output control module 44 can be used to acquire each rising edge of the pulse width modulation signal and delay the rising edge for a preset time to generate a first pulse width modulation signal; acquire each falling edge of the pulse width modulation signal and delay the falling edge for the preset time to generate a second pulse width modulation signal; and invert the second pulse width modulation signal to obtain a third pulse width modulation signal; control the switching transistors of the upper arm of the bridge inverter circuit to turn on and off through the first pulse width modulation signal, and control the switching transistors of the lower arm of the bridge inverter circuit to turn on and off through the third pulse width modulation signal.

[0064] In specific application scenarios, the signal generation module 43 can be used to obtain the preset proportional gain and integral gain required during the proportional-integral adjustment process; determine the error energy value based on the first error value and the second error value, and determine whether the error energy value is within a preset energy range; when the error energy value exceeds the energy range, increase the proportional gain of the proportional-integral adjustment, and perform proportional-integral adjustment on the first error value and the second error value respectively to obtain a modulation signal; when the error energy value is less than the energy range, decrease the integral gain of the proportional-integral adjustment, and perform proportional-integral adjustment on the first error value and the second error value respectively to obtain a modulation signal.

[0065] In a specific application scenario, the signal generation module 43 can be used to determine whether the proportional gain is higher than a preset upper limit value for proportional gain. If the proportional gain is not higher than the upper limit value for proportional gain, the proportional gain is multiplied by a preset first coefficient to obtain the improved proportional gain, wherein the first coefficient is greater than one. The reduction of the integral gain of the proportional-integral adjustment includes: determining whether the integral gain is lower than a preset lower limit value for integral gain. If the integral gain is lower than the lower limit value for integral gain, the integral gain is multiplied by a preset second coefficient to obtain the reduced integral gain, wherein the second coefficient is less than one.

[0066] It should be noted that other corresponding descriptions of the functional units involved in the output control device of the intermediate frequency power supply provided in this embodiment can be found in [reference needed]. Figure 1 The corresponding descriptions in [the document] will not be repeated here.

[0067] Based on the above, Figure 1 Accordingly, this embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements the above-described method. Figure 1 The output control method of the intermediate frequency power supply is shown.

[0068] Based on this understanding, the technical solution of this application can be embodied in the form of a software product. The software product to be identified can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, mobile hard drive, etc.) and includes several instructions to cause a computer device (such as a personal computer, server, or network device, etc.) to execute the methods described in the various implementation scenarios of this application.

[0069] Based on the above, Figure 1 The method shown, and Figure 4 The embodiment of the intermediate frequency power supply output control device shown herein, in order to achieve the above objectives, also provides a computer device for controlling the output of the intermediate frequency power supply. Specifically, this device can be a personal computer, server, smartphone, tablet computer, smartwatch, or other network device, etc. The computer device includes a storage medium and a processor; the storage medium is used to store computer programs and an operating system; the processor is used to execute the computer program to achieve the above-described... Figure 1 The method shown.

[0070] Optionally, the computer device may also include internal memory, a communication interface, a network interface, a camera, radio frequency (RF) circuitry, sensors, audio circuitry, a Wi-Fi module, a display screen, and input devices such as a keyboard. The communication interface may also include a USB interface, a card reader interface, etc. The network interface may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface).

[0071] Those skilled in the art will understand that the computer device structure for recognizing operational actions provided in this embodiment does not constitute a limitation on the computer device, and may include more or fewer components, or combine certain components, or have different component arrangements.

[0072] The storage medium may also include an operating system and a network communication module. The operating system is a program that manages the aforementioned computer hardware and the software resources to be identified, supporting the operation of information processing programs and other software and / or programs to be identified. The network communication module is used to enable communication between the various components within the storage medium, as well as communication with other hardware and software in the information processing computer device.

[0073] Through the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware platforms, or it can be implemented by hardware. By applying the technical solution of this application, firstly, the AC current output by the inverter of the intermediate frequency power supply is determined in real time, and the active current component and reactive current component of the AC current are determined; then, a preset target output current is obtained, the active current target value and reactive current target value of the target output current are determined, and a first error value between the active current target value and the active current component are determined, and a second error value between the reactive current target value and the reactive current component is determined; then, the first error value and the second error value are proportional-integral adjustment to obtain a modulation signal, and a pulse width modulation signal is generated based on the modulation signal; finally, the switching transistors in the bridge inverter circuit of the inverter are controlled to adjust the AC current output by the inverter so that the AC current approaches the target output current. Compared with the prior art, the control accuracy of the output current of the intermediate frequency power supply may be improved.

[0074] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of a preferred embodiment, and the modules or processes shown in the drawings are not necessarily essential for implementing this application. Those skilled in the art will understand that the modules in the apparatus of the embodiment can be distributed within the apparatus of the embodiment as described, or can be modified to be located in one or more apparatuses different from this embodiment. The modules of the above-described embodiment can be combined into one module, or further divided into multiple sub-modules.

[0075] The serial numbers in this application are for descriptive purposes only and do not represent the superiority or inferiority of any particular implementation scenario. The above disclosures are merely a few specific implementation scenarios of this application; however, this application is not limited thereto, and any variations conceived by those skilled in the art should fall within the protection scope of this application.

Claims

1. An output control method for a medium-frequency power supply, used to control the output current of the inverter of the medium-frequency power supply, characterized in that, The method includes: The AC current output by the inverter of the intermediate frequency power supply is determined in real time, and the active current component and reactive current component of the AC current are determined. Obtain a preset target output current, determine the active current target value and reactive current target value of the target output current, determine the first error value between the active current target value and the active current component, and determine the second error value between the reactive current target value and the reactive current component. A modulation signal is obtained by performing proportional-integral adjustment on the first error value and the second error value, and a pulse width modulation signal is generated based on the modulation signal; The switching transistors in the bridge inverter circuit of the inverter are controlled to turn on and off based on the pulse width modulation signal, so as to adjust the AC current output by the inverter so that the AC current approaches the target output current.

2. The method according to claim 1, characterized in that, The intermediate frequency power supply is a three-phase AC power supply; the AC current includes phase A AC current, phase B AC current, and phase C AC current; determining the active current component and reactive current component of the AC current includes: The A-phase AC current, the B-phase AC current, and the C-phase AC current are subjected to αβ transformation to obtain the α current component and the β current component, and the instantaneous phase angle of the AC voltage output by the inverter of the intermediate frequency power supply is determined. Based on the instantaneous phase angle, the α current component and the β current component are subjected to dq transformation to obtain the active current component and the reactive current component.

3. The method according to claim 1, characterized in that, The step of performing proportional-integral adjustment on the first error value and the second error value to obtain a modulation signal, and generating a pulse width modulation signal based on the modulation signal, includes: The first error value is proportional-integral adjusted to obtain the d-axis voltage command signal, and the second error value is proportional-integral adjusted to obtain the q-axis voltage command signal. Perform an inverse Park transform on the d-axis voltage command signal and the q-axis voltage command signal to obtain the α-axis voltage command signal and the β-axis voltage command signal; The α-axis voltage command signal and the β-axis voltage command signal are subjected to space vector modulation to obtain the pulse width modulation signal.

4. The method according to claim 1, characterized in that, The intermediate frequency power supply is an intermediate frequency power supply that outputs single-phase AC power; the real-time determination of the AC current output by the inverter of the intermediate frequency power supply, and the determination of the active current component and reactive current component of the AC current, includes: Obtain the AC current output by the inverter, and delay the phase of the AC current by 90 degrees to obtain an orthogonal AC current; The instantaneous phase angle of the AC voltage output by the inverter of the intermediate frequency power supply is determined. Based on the instantaneous phase angle, the AC current and the orthogonal AC current are subjected to dq transformation to obtain the active current component and the reactive current component.

5. The method according to claim 2, characterized in that, The method of controlling the switching transistors in the bridge inverter circuit of the inverter based on the pulse width modulation signal to adjust the AC current output by the inverter includes: Each rising edge in the pulse width modulation signal is acquired, and the rising edge is delayed by a preset time to generate a first pulse width modulation signal; Each falling edge in the pulse width modulation signal is acquired, and the falling edge is delayed by the preset time to generate a second pulse width modulation signal. The second pulse width modulation signal is then inverted to obtain a third pulse width modulation signal. The switching transistors of the upper arm of the bridge inverter circuit are controlled to turn on and off by the first pulse width modulation signal, and the switching transistors of the lower arm of the bridge inverter circuit are controlled to turn on and off by the third pulse width modulation signal.

6. The method according to claim 5, characterized in that, The step of obtaining a modulation signal by proportional-integral adjustment of the first error value and the second error value includes: Obtain the preset proportional gain and integral gain required during the proportional-integral adjustment process; Based on the first error value and the second error value, an error energy value is determined, and it is determined whether the error energy value is within a preset energy range; When the error energy value exceeds the energy range, the proportional gain of the proportional-integral adjustment is increased, and proportional-integral adjustment is performed on the first error value and the second error value respectively to obtain the modulation signal; When the error energy value is less than the energy range, the integral gain of the proportional-integral adjustment is reduced, and proportional-integral adjustment is performed on the first error value and the second error value respectively to obtain the modulation signal.

7. The method according to claim 6, characterized in that, The improvement of the proportional gain of the proportional-integral adjustment includes: Determine whether the proportional gain is higher than a preset proportional gain upper limit. If the proportional gain is not higher than the proportional gain upper limit, multiply the proportional gain by a preset first coefficient to obtain the improved proportional gain, wherein the first coefficient is greater than one. The reduction of the integral gain of the proportional-integral adjustment includes: Determine whether the integral gain is lower than a preset lower limit of integral gain. If the integral gain is lower than the lower limit of integral gain, multiply the integral gain by a preset second coefficient to obtain the reduced integral gain, wherein the second coefficient is less than one.

8. An output control device for a medium-frequency power supply, characterized in that, The device includes: The current processing module is used to determine the AC current output by the inverter of the intermediate frequency power supply in real time, and to determine the active current component and reactive current component of the AC current. An error identification module is used to acquire a preset target output current, determine the active current target value and reactive current target value of the target output current, determine a first error value between the active current target value and the active current component, and determine a second error value between the reactive current target value and the reactive current component. The signal generation module is used to perform proportional-integral adjustment on the first error value and the second error value to obtain a modulation signal, and generate a pulse width modulation signal based on the modulation signal; The output control module is used to control the switching transistors in the bridge inverter circuit of the inverter based on the pulse width modulation signal, so as to adjust the AC current output by the inverter so that the AC current approaches the target output current.

9. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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