CN114867142B - Decoupling adjustment method for output power of synchronous dual-frequency induction heating power supply - Google Patents
Decoupling adjustment method for output power of synchronous dual-frequency induction heating power supply Download PDFInfo
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/02—Induction heating
- H05B6/06—Control, e.g. of temperature, of power
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/02—Induction heating
- H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
- H05B6/101—Induction heating apparatus, other than furnaces, for specific applications for local heating of metal pieces
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
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Abstract
The invention discloses a decoupling adjustment method for output power of a synchronous double-frequency induction heating power supply, which comprises the following steps of: step A: the detection module adopts a voltage amplitude detection method based on a phase-sensitive detection technology to detect the output voltage v of the full-bridge inverter out Sampling to obtain an intermediate-frequency output voltage Vm and a high-frequency output voltage Vh; and B: the control and modulation module acquires a high-frequency output reference voltage Vhr, an intermediate-frequency output reference voltage Vmr, an intermediate-frequency output voltage Vm and a high-frequency output voltage Vh; and C: calculating a difference A between Vhr and Vh; calculating a difference value B between Vmr and Vm; step D: calculating the amplitude K and the phase difference theta of the two paths of sine wave modulation signals by a PI control method; and E, step E: two sine wave modulation signals SPWMA and SPWMB are generated by an improved SPWM method to drive the full-bridge inverter to work. According to the invention, accurate decoupling adjustment can be realized by a voltage amplitude detection method based on a phase-sensitive detection technology and a PI control method.
Description
Technical Field
The invention relates to the technical field of metal piece heat treatment, in particular to a decoupling adjusting method for output power of a synchronous double-frequency induction heating power supply.
Background
In order to solve the problem of heat treatment of metal parts with complex surface structures, a dual-frequency induction heating method is proposed.
When induction heating is carried out on a metal workpiece with a relatively complex surface structure, the single-frequency induction heating hardly meets the process requirements due to the difference of the thicknesses of different parts. The double-frequency power supply can output two alternating magnetic fields with different frequencies through the induction coil, can form two eddy currents with different penetration depths on the surface of a workpiece, and further can uniformly heat the workpiece in a large range. Currently, there are many papers and patents on the study and verification of the dual frequency induction heating method, such as:
esteve et al, in "High Power sensitive Inverter with Simultaneous Dual-frequency Output", propose a Dual-Resonant quad-component circuit having a Dual-frequency-selective characteristic, capable of filtering out other harmonics in a mixing signal except for intermediate-frequency and High-frequency signals, which is the basis of a series-connected synchronous Dual-frequency induction Power supply. The article does not achieve decoupled regulation of the dual frequency output.
Patent ZL202110419012.8 designs a heat treatment device based on asynchronous dual-frequency induction heating from control gear even, and the device is infrared temperature measurement jointly to feedback control induction coil and heated gear between the distance, the switching and corresponding power between the intermediate frequency high frequency current output mode. However, this method is asynchronous dual-frequency induction heating, is not dual-frequency heating in a strict sense, and requires a more complicated time-sharing heating strategy.
Patent ZL202111264910.7 discloses an arbitrary working method of a double-frequency induction heating main circuit, which can arbitrarily adjust the frequency grade relation of a double-frequency output signal. However, the induction heating power supply needs 6 switching tubes and three adjustable direct current power supplies, and the cost is high.
The defects of the prior art are as follows: a decoupling adjustment method for output power of a synchronous dual-frequency induction heating power supply is lacked, a large voltage output range is provided for the dual-frequency power supply through an improved SPWM method, and accurate decoupling adjustment is achieved through a voltage amplitude detection method based on a phase-sensitive detection technology and a PI control method.
Disclosure of Invention
In view of at least one defect of the prior art, an object of the present invention is to provide a decoupling adjustment method for output power of a synchronous dual-frequency induction heating power supply, in which the improved SPWM method provided by the present invention can provide a larger voltage output range for a dual-frequency power supply, and accurate decoupling adjustment can be achieved by a voltage amplitude detection method based on a phase-sensitive detection technique and a PI control method.
In order to achieve the purpose, the invention adopts the following technical scheme: the utility model provides a decoupling zero governing method for synchronous double-frequency induction heating power output, is used for a decoupling zero governing system, and decoupling zero governing system includes the hardware module, and the hardware module is provided with the full-bridge dc-to-ac converter, and the output end group of full-bridge dc-to-ac converter is connected with dual resonance quaternary structure, and the output end group of full-bridge dc-to-ac converter still is connected with detection module, and detection module is connected with control and modulation module, and control and modulation module connects the control end group drive its work of full-bridge dc-to-ac converter, includes following step:
step A: the detection module adopts a voltage amplitude detection method based on a phase-sensitive detection technology to detect the output voltage v of the full-bridge inverter out Sampling is carried out, and the intermediate frequency output voltage Vm and the high frequency output voltage Vh of the full-bridge inverter are respectively obtained and transmitted to a control and modulation module;
and B, step B: the control and modulation module acquires a high-frequency output reference voltage Vhr, an intermediate-frequency output reference voltage Vmr, an intermediate-frequency output voltage Vm and a high-frequency output voltage Vh;
and C: the control and modulation module calculates a difference value A between the high-frequency output reference voltage Vhr and the high-frequency output voltage Vh; calculating a difference B between the intermediate-frequency output reference voltage Vmr and the intermediate-frequency output voltage Vm;
step D: the control and modulation module acquires the difference value A and the difference value B and calculates the amplitude K of the two paths of sine wave modulation signals and the phase difference theta between the two paths of sine wave modulation signals through a PI control method;
step E: the control and modulation module obtains K and theta, and two sine wave modulation signals SPWMA and SPWMB are generated by an improved SPWM method to drive the full-bridge inverter to work.
The full-bridge inverter is provided with a power switch tube S 1 Power switch tube S 2 Power switch tube S 3 And a power switch tube S 4 (ii) a Power switch tube S 1 D pole of the power switch tube is connected with the anode of a direct current power supply E and a power switch tube S 1 S pole of the power switch tube S 2 D pole of (1), power switch tube S 2 S pole of the power switch tube is connected with the negative pole of the direct current power supply E 4 D pole of the power switch is connected with the anode of a direct current power supply E, and a power switch tube S 4 S pole of the power switch tube S 3 D pole of (1), power switch tube S 3 S pole of the power switch tube is connected with the negative pole of a direct current power supply E, and the power switch tube S 1 S pole and power switch tube S 4 The S pole is used as an output end group of the full-bridge inverter and is connected with a dual-resonance four-element structure; power switch tube S 1 Control end G and power switch tube S 2 Control end G and power switch tube S 3 Control terminal G and power switch tube S 4 The control end G of the control module is connected with the control and modulation module;
the dual-resonance four-element structure is provided with an inductor L1, a capacitor C2, an inductor L2 and a resistor R, wherein the inductor L2 and the resistor R are equivalent inductance and equivalent resistance of the induction coil; one end of the capacitor C2 is connected with a power switch tube S 1 One end of the capacitor C2 is also connected with one end of the inductor L1, the other end of the inductor L1 is connected with the other end of the capacitor C1, the other end of the capacitor C1 is connected with one end of the inductor L2 after being connected with the other end of the capacitor C2 in parallel, and the other end of the inductor L2 is connected with the power switch tube S through the resistor R 4 The S pole of (1).
In the step A, the detection module adopts a voltage amplitude detection method based on a phase-sensitive detection technology to detect the output voltage v of the full-bridge inverter out Sampling is carried out, the intermediate frequency output voltage Vm and the high frequency output voltage Vh of the full-bridge inverter are respectively obtained and are transmitted to the control and modulation module, and the control and modulation module comprises:
the detection module is provided with a first PSD detector and a second PSD detector, and two input end groups of the first PSD detector and two input end groups of the second PSD detector are connected with an output end group of the full-bridge inverter;
the first PSD detector and the second PSD detector are used for detecting the output voltage v of the full-bridge inverter by a voltage amplitude detection method based on a phase-sensitive detection technology out And sampling to respectively obtain the intermediate-frequency output voltage Vm and the high-frequency output voltage Vh of the full-bridge inverter.
The first PSD detector detects the output voltage v of the full-bridge inverter by a voltage amplitude detection method based on a phase-sensitive detection technology out The sampling is carried out to obtain the intermediate frequency output voltage Vm of the full-bridge inverter, and the method comprises the following steps:
the first PSD detector is provided with a first Mul multiplication operation module and a second Mul multiplication operation module, and the first Mul multiplication operation module and the second Mul multiplication operation module are connected with an output end group of the full-bridge inverter to obtain output voltage v out ；
The first Mul multiplication module outputs the output voltage v out And the quadrature voltage signal Ccos (ω) m t) performing multiplication(ii) a Where C is a fixed known constant, ω m Is the intermediate frequency signal angular frequency;
the first Mul multiplication operation module is connected with a first LPF low-pass filtering module, and the first LPF low-pass filtering module performs filtering processing on an operation result of the first Mul multiplication operation module to obtain a signal a1;
the second Mul multiplication module outputs the voltage v out Quadrature voltage signal Csin (ω) m t) performing multiplication operation;
the second Mul multiplication operation module is connected with a second LPF low-pass filtering module, and the second LPF low-pass filtering module performs filtering processing on the operation result of the second Mul multiplication operation module to obtain a signal b1;
the first LPF low-pass filtering module and the second LPF low-pass filtering module are connected with a first a/b division operation module; the first a/b division operation module divides the signal a1 by the signal b1;
the first a/b division operation module is connected with a first atan arc tangent operation module, and the first atan arc tangent operation module performs arc tangent operation on the operation result of the first a/b division operation module;
the first atan arc tangent operation module is connected with a first cos cosine operation module, and the first cos cosine operation module performs cosine operation on an operation result of the first atan arc tangent operation module to obtain a signal d1;
the second LPF low-pass filtering module is also connected with a first 2/C multiplication operation module, and the first 2/C multiplication operation module multiplies the signal b1 by 2/C to obtain a signal C1;
the first cos cosine operation module and the first 2/C multiplication operation module are connected with a first C/d division operation module; the first c/d division operation module divides the signal c1 by the signal d1;
the first c/d division operation module is connected with a first abs absolute value operation module, and the first abs absolute value operation module obtains an absolute value of an operation result of the first c/d division operation module to obtain an intermediate-frequency output voltage Vm.
The second PSD detector detects the output voltage v of the full-bridge inverter by a voltage amplitude detection method based on a phase-sensitive detection technology out Sampling to obtain the high-frequency output of the full-bridge inverterThe output voltage Vh includes:
the second PSD is provided with a third Mul multiplication operation module and a fourth Mul multiplication operation module, and the third Mul multiplication operation module and the fourth Mul multiplication operation module are connected with an output end group of the full-bridge inverter to obtain output voltage v out ；
The third Mul multiplication operation module outputs the voltage v out And the quadrature voltage signal Ccos (ω) h t) performing multiplication operation; where C is a fixed known constant, ω h Is the high frequency signal angular frequency;
the third Mul multiplication operation module is connected with a third LPF low-pass filtering module, and the third LPF low-pass filtering module performs filtering processing on the operation result of the third Mul multiplication operation module to obtain a signal a2;
the fourth Mul multiplication operation module outputs the voltage v out Quadrature voltage signal Csin (ω) h t) performing multiplication operation;
the fourth Mul multiplication operation module is connected with a fourth LPF low-pass filtering module, and the fourth LPF low-pass filtering module performs filtering processing on the operation result of the fourth Mul multiplication operation module to obtain a signal b2;
the third LPF low-pass filtering module and the fourth LPF low-pass filtering module are connected with a second a/b division operation module; the second a/b division operation module divides the signal a2 by the signal b2;
the second a/b division operation module is connected with a second atan arc tangent operation module, and the second atan arc tangent operation module performs arc tangent operation on the operation result of the second a/b division operation module;
the second atan arc tangent operation module is connected with a second cos cosine operation module, and the second cos cosine operation module performs cosine operation on the operation result of the second atan arc tangent operation module to obtain a signal d2;
the fourth LPF low-pass filtering module is also connected with a second 2/C multiplication operation module, and the second 2/C multiplication operation module multiplies the signal b2 by 2/C to obtain a signal C2;
the second cos cosine operation module and the second 2/C multiplication operation module are connected with a second C/d division operation module; the second c/d division operation module divides the signal c2 by the signal d2;
the second c/d division operation module is connected with a second abs absolute value calculation module, and the second abs absolute value calculation module obtains the absolute value of the operation result of the second c/d division operation module to obtain the high-frequency output voltage Vh.
In step B, the control and modulation module obtaining the high frequency output reference voltage Vhr, the intermediate frequency output reference voltage Vmr, the intermediate frequency output voltage Vm and the high frequency output voltage Vh includes:
the control and modulation module is provided with a first negative feedback module and a second negative feedback module, and the first negative feedback module acquires a high-frequency output reference voltage Vhr and a high-frequency output voltage Vh; the second negative feedback module acquires an intermediate frequency output reference voltage Vmr and an intermediate frequency output voltage Vm;
the first negative feedback module is connected with the second PSD detector to obtain high-frequency output voltage Vh; the second negative feedback module is connected with the first PSD to obtain the intermediate-frequency output voltage Vm;
in the step C; the control and modulation module calculates a difference value A between the high-frequency output reference voltage Vhr and the high-frequency output voltage Vh; calculating the difference B between the intermediate frequency output reference voltage Vmr and the intermediate frequency output voltage Vm includes:
the first negative feedback module calculates a difference value A between the high-frequency output reference voltage Vhr and the high-frequency output voltage Vh; the second negative feedback module calculates a difference B between the intermediate frequency output reference voltage Vmr and the intermediate frequency output voltage Vm.
The first negative feedback module and the second negative feedback module can also be called a first subtraction module and a second subtraction module.
In the step D, the step of calculating the amplitude K of the two sinusoidal modulation signals and the phase difference θ between the two sinusoidal modulation signals by the control and modulation module through obtaining the difference a and the difference B by the PI control method includes:
the control and modulation module is also provided with a first PI controller and a second PI controller, and the first PI controller is connected with the first negative feedback module; the second PI controller is connected with the second negative feedback module; the first PI controller obtains the difference value A to calculate the amplitude K of the two sine wave modulation signals; and the second PI controller acquires the difference B and calculates the phase difference theta between the two sine wave modulation signals.
The first PI controller obtains the difference value A and calculates the amplitude K of the two sine wave modulation signals; the step of obtaining the difference value B and calculating the phase difference theta between the two sine wave modulation signals by the second PI controller comprises the following steps:
calculating the amplitude K and the phase difference theta of the two paths of sine wave modulation signals by adopting a formula (1);
in the formula (1), K is the amplitude of the two sine wave modulation signals, theta is the phase difference of the two sine wave modulation signals, and P k Is the P coefficient, I, of the first PI controller k Is the I coefficient, P, of the first PI controller θ Is the P coefficient, I, of the second PI controller θ Is the I coefficient of the second PI controller.
In the step E; the control and modulation module obtains K and theta, and two sine wave modulation signals SPWMA and SPWMB are generated by an improved SPWM method to drive the full-bridge inverter to work, and the method comprises the following steps:
the control and modulation module is also provided with an SPWM-A sine modulation wave generator and an SPWM-B sine modulation wave generator; the SPWM-A sine modulation wave generator is connected with the first PI controller to obtain the amplitude K and generate a first sine modulation wave signal SPWMA; the SPWM-B sine modulation wave generator is connected with the first PI controller and the second PI controller to obtain an amplitude K and a phase difference theta to generate a second sine modulation wave signal SPWMB;
the equations of the first sinusoidal modulated wave signal SPWMA and the second sinusoidal modulated wave signal SPWMB are as shown in equation (2):
f m is the intermediate frequency resonance frequency of the circuit;
the output end of the SPWM-A sine modulation wave generator is connected with a power switch tube S of the full-bridge inverter 1 The control terminal G of (2); the output end of the SPWM-A sine modulation wave generator is connected with a power switch tube S of a full-bridge inverter through a first inverter 2 The control terminal G of (2); the output end of the SPWM-B sine modulation wave generator is connected with a power switch tube S of the full-bridge inverter 3 The control terminal G of (2); the output end of the SPWM-B sine modulation wave generator is connected with a power switch tube S of a full-bridge inverter through a second inverter 4 The control terminal G of (1).
The two sine wave modulation signals SPWMA and SPWMB are provided with carrier waves, the carrier waves are bipolar triangular waves CW, the amplitude value is a fixed value A, and the frequency is equal to the high-frequency resonant frequency of the circuit.
Comparing the SPWMA signal with the CW signal, and turning on the power switch tube S when the SPWMA signal is greater than the CW signal 1 Turning off the power switch tube S 2 (ii) a When the value of SPWMA is less than the value of CW, the power switch tube S is turned on 2 Turning off the power switch tube S 1 . Comparing the SPWMB signal with the CW signal, and turning on the power switch tube S when the SPWMB signal is greater than the CW signal 3 Turning off the power switch tube S 4 (ii) a When the value of SPWMB is less than the value of CW, the power switch tube S is opened 4 Turning off the power switch tube S 3 。
The improved SPWM method can provide a large voltage output range for the dual-frequency power supply, and can realize accurate decoupling adjustment through a voltage amplitude detection method based on a phase-sensitive detection technology and a PI control method.
Drawings
FIG. 1 is a topological structure diagram of a dual frequency induction heating power supply system;
FIG. 2 is a schematic diagram of a proposed improved SPWM modulation method;
FIG. 3 is a flow chart of a voltage amplitude detection method based on phase-sensitive detection;
FIG. 4 illustrates the adjustable range of the dual-frequency output voltage of the present invention;
FIG. 5 is a target tracking curve of high frequency voltage output in the dual frequency power supply control output curve of the present invention;
FIG. 6 is a target tracking curve of the IF voltage output in the dual-band power control output curve of the present invention;
FIG. 7 is a flow chart of the method of the present invention.
Detailed Description
The invention is described in further detail below with reference to the figures and specific examples.
As shown in fig. 1 to 7, the invention discloses a decoupling adjustment method for output power of a synchronous dual-frequency induction heating power supply, which is capable of realizing wide-range accurate adjustment of dual-frequency power output, wherein the dual-frequency power supply based on a full-bridge inverter and a dual-resonance four-element circuit can be used for induction heating of metal parts with complex structures including but not limited to gears. The whole decoupling method comprises an improved SPWM modulation method, a voltage amplitude detection method based on a phase-sensitive detection technology and a PI control method.
1. The PI controller equation:
in the PI controller equation, K is the amplitude of two sinusoidal modulation wave signals, theta is the phase difference between the two sinusoidal modulation wave signals, and P j For the controller P coefficient, I j For the controller I coefficients (j = θ, K), vmr is the intermediate frequency voltage reference value, vm is the intermediate frequency voltage actual output value, vhr is the high frequency voltage reference value, and Vh is the high frequency voltage actual output value.
2. The improved SPWM modulation schematic diagram is shown in FIG. 2; FIG. 2a is a waveform diagram of an SPWM-1 modulated wave signal and an SPWM-2 modulated wave signal, and FIG. 2b is a waveform diagram of a CW carrier signal; the invention comprises an improved SPWM modulation method, wherein SPWM-1 is S 1-2 A modulated wave of bridge arm drive signal, SPWM-2 being S 3-4 The modulated wave of the bridge arm driving signal, CW is the carrier wave of the two driving signals, K is the amplitude of the two modulated waves, and theta is the phase difference of the two modulated waves.
3. The schematic diagram of the voltage amplitude detection method based on the phase-sensitive detection technology is shown in fig. 3;
FIG. 3a is a flow chart of a method for detecting the amplitude of an intermediate frequency voltage based on a phase-sensitive detection technique;
FIG. 3b is a flow chart of a high frequency voltage amplitude detection method based on phase sensitive detection technique;
in the voltage amplitude detection method schematic diagram based on the phase-sensitive detection technology, fig. 3a is a schematic diagram of a medium-frequency voltage detection principle, fig. 3b is a schematic diagram of a high-frequency voltage detection principle, vout is a full-bridge inverter output voltage signal, V m Is the amplitude of the intermediate frequency voltage component, V h Is the amplitude of the high frequency voltage component, sin is the sine module, cos is the cosine module, ω m At the angular frequency, omega, of the intermediate frequency signal h The angular frequency of a high-frequency signal is shown, mul is a multiplication module, LPF is a low-pass filtering module, a and b are direct-current signals after filtering, C is a fixed known constant, a/b and C/d represent division operation, 2/C is a multiplication module, atan is an arc tangent operation module, and abs is an absolute value operation module.
Aiming at the problems in the prior art, the invention provides a decouplable adjustable dual-frequency induction heating power supply based on a single inverter and a dual-resonance four-element circuit. The improved SPWM method provided by the invention can provide a larger voltage (power) output range for a dual-frequency power supply, and can realize accurate decoupling adjustment through a voltage amplitude detection method based on a phase-sensitive detection technology and a PI control method.
SPWM modulation is used for the dual frequency power supply.
The modulated wave equation is as follows:
SPWMA is power switch tube S 1 And a power switch tube S 2 The amplitude of the modulated signal of (2) is the system input K, which ranges from 0 to 5A. SPWMB is power switch tube S 3 And a power switch tube S 4 The amplitude of the modulated signal of (2) is the system input K, theta is the phase difference of the two modulated signals, is the other input of the system, and ranges from 0-pi. f. of m Is the circuit intermediate frequency resonance frequency.
The carrier wave is bipolar triangular wave CW, the amplitude is a fixed value A, and the frequency is equal to the high-frequency resonant frequency of the circuit.
Comparing the magnitude of SPWMA and CW, when the value of SPWMA is greater than that of CW, turning on power switch tube S 1 Turning off the power switch tube S 2 (ii) a When the value of SPWMA is less than the value of CW, the power switch tube S is turned on 2 Turning off the power switch tube S 1 . Comparing the magnitude of SPWMB with CW, when the value of SPWMB is greater than CW, turning on power switch tube S 3 Turning off the power switch tube S 4 (ii) a When the value of SPWMB is less than that of CW, the power switch tube S is turned on 4 Turning off the power switch tube S 3 。
The improved SPWM modulation mode can provide a larger adjustable range for system output.
The invention adopts a signal detection method based on phase-sensitive detection, and the method can extract the amplitude and the phase of harmonic components with known frequency from a mixed signal.
The intermediate frequency output voltage of the full-bridge inverter is taken as a detection target, a pair of orthogonal signals are multiplied by a midpoint voltage signal of a bridge arm of the full-bridge inverter, the amplitude of each orthogonal signal is known and fixed, and the frequency is the frequency of the target signal, so that a pair of new mixing signals can be obtained.
And passing the new mixing signal through a low-pass filter to obtain a pair of direct current signals. The representation is as follows:
where C is the amplitude of the quadrature signal, V m In order to detect the amplitude of the target signal,
to detect the phase of the target signal.
The amplitude of the detected target signal can be obtained as follows:
the detection principle of the high frequency output voltage is the same as the intermediate frequency, except that the frequency of the multiplied set of quadrature signals is the frequency of the high frequency target signal.
Two PI controllers are adopted to realize the output regulation of double-frequency voltage, and the equation is as follows:
where K is the amplitude of two sinusoidal modulated waves, theta is the phase difference between the two sinusoidal waves, P j For the controller P coefficient, I j For the controller I coefficients (j = θ, K), vmr is the intermediate frequency voltage reference value, vm is the intermediate frequency voltage actual output value, vhr is the high frequency voltage reference value, and Vh is the high frequency voltage actual output value.
The invention is further illustrated with reference to the following figures and examples.
As shown in fig. 1, a decoupling adjustment method for output power of a synchronous dual-frequency induction heating power supply is implemented based on a synchronous dual-frequency power supply system, and the whole system is composed of a hardware module, a control and modulation module and a detection module. The hardware module mainly comprises a full-bridge inverter and a dual-resonance four-element structure, wherein R-L 2 The series element is equivalent to an induction coil.
The output end group of the full-bridge inverter is connected with a detection module, the detection module is connected with a control and modulation module, and the control and modulation module is connected with the control end group of the full-bridge inverter to drive the control end group to work.
The full-bridge inverter is provided with a power switch tube S 1 Power switch tube S 2 Power switch tube S 3 And a power switch tube S 4 (ii) a Power switch tube S 1 D pole of the power switch is connected with the anode of a direct current power supply E, and a power switch tube S 1 S pole of the power switch tube S 2 D pole of (1), power switch tube S 2 S pole of the power switch tube is connected with the negative pole of the direct current power supply E 4 D pole of the power switch tube is connected with the anode of a direct current power supply E and a power switch tube S 4 S pole of the power switch tube S 3 D pole of (D), power switch tube S 3 S ofThe pole of the DC power supply E is connected with the negative pole of the power switch tube S 1 S pole and power switch tube S 4 The S pole is used as an output end group of the full-bridge inverter and is connected with a double-resonance four-element structure; power switch tube S 1 Control end G and power switch tube S 2 Control end G and power switch tube S 3 Control terminal G and power switch tube S 4 The control end G of the control module is connected with the control and modulation module;
the dual-resonance four-element structure is provided with an inductor L1, a capacitor C2, an inductor L2 and a resistor R, wherein the inductor L2 and the resistor R are equivalent inductance and equivalent resistance of the induction coil; one end of the capacitor C2 is connected with a power switch tube S 1 One end of the capacitor C2 is also connected with one end of the inductor L1, the other end of the inductor L1 is connected with the other end of the capacitor C1, the other end of the capacitor C1 is connected with one end of the inductor L2 after being connected with the other end of the capacitor C2 in parallel, and the other end of the inductor L2 is connected with the power switch tube S through the resistor R 4 The S pole of (1).
The control and modulation module is provided with an SPWM-A sine modulation wave generator (SPWM-1) and an SPWM-B sine modulation wave generator (SPWM-2);
the output end of the SPWM-A sine modulation wave generator is connected with a power switch tube S of the full-bridge inverter 1 The control terminal G of (2); the output end of the SPWM-A sine modulation wave generator is connected with a power switch tube S of a full-bridge inverter through a first inverter 2 The control terminal G of (2); the output end of the SPWM-B sine modulation wave generator is connected with a power switch tube S of the full-bridge inverter 3 The control terminal G of (2); the output end of the SPWM-B sine modulation wave generator is connected with a power switch tube S of a full-bridge inverter through a second inverter 4 The control terminal G of (1).
The two resonant frequencies of the power supply can be chosen arbitrarily by suitable component design methods. The specific implementation method comprises the following steps: for inverter output voltage, i.e. midpoint voltage v of two bridge arms out The sampling is performed, and the high-frequency output voltage Vh and the intermediate-frequency output voltage Vm of the inverter are obtained through two PSD detectors as shown in fig. 3. The output reference voltages Vhr and Vmr of the inverter are set, and the reference values should be within the adjustable range as shown in fig. 4. Adding Vhr and-Vh, adding Vmr and-Vm, and sending to PI controllerObtaining the amplitude K of the two paths of modulation signals and the phase difference theta between the two paths of modulation signals. As shown in fig. 2, two modulation signals SPWMA and SPWMB in the modulation module are obtained through the values K and θ, and then are modulated by the SPWM to generate a driving signal to drive the bridge arm of the full-bridge inverter.
The component parameters in this example were chosen as follows: e =100v, r =0.5 Ω, L1=400 μ H, L2=30 μ H, C1=262nf, C2=22.7nf. Therefore, the resonance frequency of the circuit is 15KHz and 200KHz, in order to enable the circuit to work in a resonance state, the frequency of the triangular carrier wave in the modulation module is set to be 200KHz, the amplitude is set to be 10V, and the frequency of the sinusoidal modulation wave is 15KHz. The setting of the voltage regulation reference value is divided into 5 stages: stage 1: vhr =120v, vmr =20v (0 s < = t <0.15 s); and 2, stage: vhr =70v, vmr =20v (1.5 s < = t <0.3 s); stage 3: vhr =20v, vmr =20v (0.3 s < = t <0.45 s); and 4, a stage: vhr =20v, vmr =70v (0.3 s < = t <0.45 s); stage 5: vhr =20v, vmr =120v (0.3 s < = t <0.45 s). The verification results are shown in fig. 5-6.
Fig. 5-6 show tracking curves of the output voltage of the full-bridge inverter, i.e., the midpoint voltage of two bridge arms, where the red line is the reference voltage, i.e., the adjustment target value, and the blue line is the actual output voltage, and it can be seen that the system can reach a steady state within 0.1s, i.e., the rapid adjustment of the output is realized. Fig. 5 shows a high-frequency output adjustment process, fig. 6 shows a medium-frequency output adjustment process, and it can be seen from the legend that the decoupling adjustment method for synchronizing the output power of the dual-frequency induction heating power supply of the present invention can achieve large-range adjustment of the dual-frequency induction heating power supply based on the full-bridge inverter and the dual-resonance four-element circuit, and can achieve precise adjustment of the dual-frequency output.
Finally, it is noted that: the above-mentioned embodiments are only examples of the present invention, and it is a matter of course that those skilled in the art can make modifications and variations to the present invention, and it is considered that the present invention is protected by the modifications and variations if they are within the scope of the claims of the present invention and their equivalents.
Claims (10)
1. The utility model provides a decoupling zero governing method for synchronous dual-frenquency induction heating power output, a decoupling zero governing system, decoupling zero governing system includes the hardware module, the hardware module is provided with the full-bridge dc-to-ac converter, the output of full-bridge dc-to-ac converter group is connected with two resonance quaternary structure, the output of full-bridge dc-to-ac converter group still is connected with detection module, detection module is connected with control and modulation module, control and modulation module connect the control end group drive its work of full-bridge dc-to-ac converter, a serial communication port, including the following step:
step A: the detection module adopts a voltage amplitude detection method based on a phase-sensitive detection technology to output voltage v of the full-bridge inverter out Sampling is carried out, and the intermediate frequency output voltage Vm and the high frequency output voltage Vh of the full-bridge inverter are respectively obtained and transmitted to the control and modulation module;
and B: the control and modulation module acquires a high-frequency output reference voltage Vhr, an intermediate-frequency output reference voltage Vmr, an intermediate-frequency output voltage Vm and a high-frequency output voltage Vh;
and C: the control and modulation module calculates a difference value A between the high-frequency output reference voltage Vhr and the high-frequency output voltage Vh, and calculates a difference value B between the intermediate-frequency output reference voltage Vmr and the intermediate-frequency output voltage Vm;
step D: the control and modulation module calculates the amplitude K of the two sine wave modulation signals and the phase difference theta between the two sine wave modulation signals through a PI control method;
step E: the control and modulation module generates two sine wave modulation signals SPWMA and SPWMB through an improved SPWM method to drive the full-bridge inverter to work.
2. The decoupled regulation method for output power of a synchronous dual-band induction heating power supply of claim 1, characterized in that: the full-bridge inverter is provided with a power switch tube S 1 Power switch tube S 2 Power switch tube S 3 And a power switch tube S 4 (ii) a Power switch tube S 1 D pole of the power switch tube is connected with the anode of a direct current power supply E and a power switch tube S 1 S pole of the power switch tube S 2 D pole of (1), power switch tube S 2 S pole of the power switch tube is connected with the negative pole of the direct current power supply E 4 D pole of the DC power supplyE positive pole, power switch tube S 4 S pole of the power switch tube S 3 D pole of (1), power switch tube S 3 S pole of the power switch tube is connected with the negative pole of a direct current power supply E, and the power switch tube S 1 S pole and power switch tube S 4 The S pole is used as an output end group of the full-bridge inverter and is connected with a double-resonance four-element structure; power switch tube S 1 Control end G and power switch tube S 2 Control end G and power switch tube S 3 Control terminal G and power switch tube S 4 The control end G of the control module is connected with the control and modulation module;
the dual-resonance four-element structure is provided with an inductor L1, a capacitor C2, an inductor L2 and a resistor R, wherein the inductor L2 and the resistor R are equivalent inductance and equivalent resistance of the induction coil; one end of the capacitor C2 is connected with a power switch tube S 1 One end of the capacitor C2 is also connected with one end of the inductor L1, the other end of the inductor L1 is connected with the other end of the capacitor C1, the other end of the capacitor C1 is connected with one end of the inductor L2 after being connected with the other end of the capacitor C2 in parallel, and the other end of the inductor L2 is connected with the power switch tube S through the resistor R 4 The S pole of (1).
3. The decoupled regulation method for output power of a synchronous dual-band induction heating power supply of claim 1, characterized in that: in the step A, the detection module adopts a voltage amplitude detection method based on a phase-sensitive detection technology to detect the output voltage v of the full-bridge inverter out Sampling is carried out, the intermediate frequency output voltage Vm and the high frequency output voltage Vh of the full-bridge inverter are respectively obtained and are transmitted to the control and modulation module, and the control and modulation module comprises:
the detection module is provided with a first PSD detector and a second PSD detector, and two input end groups of the first PSD detector and two input end groups of the second PSD detector are connected with an output end group of the full-bridge inverter;
the first PSD detector and the second PSD detector detect the output voltage v of the full-bridge inverter by a voltage amplitude detection method based on a phase-sensitive detection technology out And sampling to respectively obtain the medium-frequency output voltage Vm and the high-frequency output voltage Vh of the full-bridge inverter.
4. The method of claim 3, wherein the step of decoupling the output power of the synchronous dual-band induction heating power supply comprises the steps of: the first PSD detector detects the output voltage v of the full-bridge inverter by a voltage amplitude detection method based on a phase-sensitive detection technology out The sampling to obtain the intermediate frequency output voltage Vm of the full-bridge inverter comprises the following steps:
the first PSD detector is provided with a first Mul multiplication operation module and a second Mul multiplication operation module, and the first Mul multiplication operation module and the second Mul multiplication operation module are connected with an output end group of the full-bridge inverter to obtain output voltage v out ；
The first Mul multiplication module outputs the output voltage v out And the quadrature voltage signal Ccos (ω) m t) performing multiplication operation; where C is a fixed known constant, ω m Is the intermediate frequency signal angular frequency;
the first Mul multiplication operation module is connected with a first LPF low-pass filtering module, and the first LPF low-pass filtering module performs filtering processing on an operation result of the first Mul multiplication operation module to obtain a signal a1;
the second Mul multiplication module outputs the voltage v out Quadrature voltage signal Csin (ω) m t) performing multiplication operation;
the second Mul multiplication operation module is connected with a second LPF low-pass filtering module, and the second LPF low-pass filtering module performs filtering processing on the operation result of the second Mul multiplication operation module to obtain a signal b1;
the first LPF low-pass filtering module and the second LPF low-pass filtering module are connected with a first a/b division operation module; the first a/b division operation module divides the signal a1 by the signal b1;
the first a/b division operation module is connected with a first atan arc tangent operation module, and the first atan arc tangent operation module performs arc tangent operation on the operation result of the first a/b division operation module;
the first atan arc tangent operation module is connected with a first cos cosine operation module, and the first cos cosine operation module performs cosine operation on an operation result of the first atan arc tangent operation module to obtain a signal d1;
the second LPF low-pass filtering module is also connected with a first 2/C multiplication operation module, and the first 2/C multiplication operation module multiplies the signal b1 by 2/C to obtain a signal C1;
the first cos cosine operation module and the first 2/C multiplication operation module are connected with a first C/d division operation module; the first c/d division operation module divides the signal c1 by the signal d1;
the first c/d division operation module is connected with a first abs absolute value operation module, and the first abs absolute value operation module obtains an absolute value of an operation result of the first c/d division operation module to obtain an intermediate-frequency output voltage Vm.
5. The method of claim 3, wherein the step of decoupling the output power of the synchronous dual-band induction heating power supply comprises the steps of: the second PSD detector detects the output voltage v of the full-bridge inverter by a voltage amplitude detection method based on a phase-sensitive detection technology out The sampling to obtain the high-frequency output voltage Vh of the full-bridge inverter comprises the following steps:
the second PSD is provided with a third Mul multiplication operation module and a fourth Mul multiplication operation module, and the third Mul multiplication operation module and the fourth Mul multiplication operation module are connected with the output end group of the full-bridge inverter to obtain output voltage v out ；
The third Mul multiplication operation module outputs the voltage v out And the quadrature voltage signal Ccos (ω) h t) performing multiplication operation; where C is a fixed known constant, ω h Is the high frequency signal angular frequency;
the third Mul multiplication operation module is connected with a third LPF low-pass filtering module, and the third LPF low-pass filtering module performs filtering processing on the operation result of the third Mul multiplication operation module to obtain a signal a2;
the fourth Mul multiplication operation module outputs the voltage v out Quadrature voltage signal Csin (ω) h t) performing multiplication operation;
the fourth Mul multiplication operation module is connected with a fourth LPF low-pass filtering module, and the fourth LPF low-pass filtering module performs filtering processing on the operation result of the fourth Mul multiplication operation module to obtain a signal b2;
the third LPF low-pass filtering module and the fourth LPF low-pass filtering module are connected with a second a/b division operation module; the second a/b division operation module divides the signal a2 by the signal b2;
the second a/b division operation module is connected with a second atan arc tangent operation module, and the second atan arc tangent operation module performs arc tangent operation on the operation result of the second a/b division operation module;
the second atan arc tangent operation module is connected with a second cos cosine operation module, and the second cos cosine operation module performs cosine operation on the operation result of the second atan arc tangent operation module to obtain a signal d2;
the fourth LPF low-pass filtering module is also connected with a second 2/C multiplication operation module, and the second 2/C multiplication operation module multiplies the signal b2 by 2/C to obtain a signal C2;
the second cos cosine operation module and the second 2/C multiplication operation module are connected with a second C/d division operation module; the second c/d division operation module divides the signal c2 by the signal d2;
the second c/d division operation module is connected with a second abs absolute value calculation module, and the second abs absolute value calculation module obtains the absolute value of the operation result of the second c/d division operation module to obtain the high-frequency output voltage Vh.
6. The decoupled regulation method for output power of a synchronous dual-band induction heating power supply of claim 2, characterized in that: in step B, the control and modulation module obtaining the high frequency output reference voltage Vhr, the intermediate frequency output reference voltage Vmr, the intermediate frequency output voltage Vm and the high frequency output voltage Vh includes:
the control and modulation module is provided with a first negative feedback module and a second negative feedback module, and the first negative feedback module acquires a high-frequency output reference voltage Vhr and a high-frequency output voltage Vh; the second negative feedback module acquires an intermediate frequency output reference voltage Vmr and an intermediate frequency output voltage Vm;
in the step C; the control and modulation module calculates a difference A between the high-frequency output reference voltage Vhr and the high-frequency output voltage Vh, and the calculation of a difference B between the intermediate-frequency output reference voltage Vmr and the intermediate-frequency output voltage Vm includes:
the first negative feedback module calculates a difference value A between the high-frequency output reference voltage Vhr and the high-frequency output voltage Vh; the second negative feedback module calculates a difference value B between the intermediate frequency output reference voltage Vmr and the intermediate frequency output voltage Vm.
7. The decoupled regulation method for output power of a synchronous dual-band induction heating power supply of claim 6, characterized in that: in the step D, the calculating, by the control and modulation module, the amplitude K of the two sinusoidal modulation signals and the phase difference θ between the two sinusoidal modulation signals by the PI control method includes:
the control and modulation module is also provided with a first PI controller and a second PI controller, and the first PI controller is connected with the first negative feedback module; the second PI controller is connected with the second negative feedback module; the first PI controller obtains the difference value A to calculate the amplitude K of the two sine wave modulation signals; and the second PI controller acquires the difference B and calculates the phase difference theta between the two sine wave modulation signals.
8. The decoupled regulation method for output power of a synchronous dual-band induction heating power supply of claim 7, characterized in that: the first PI controller obtains the difference value A and calculates the amplitude K of the two sine wave modulation signals; the step of obtaining the difference value B and calculating the phase difference theta between the two sine wave modulation signals by the second PI controller comprises the following steps:
calculating the amplitude K and the phase difference theta of the two paths of sine wave modulation signals by adopting a formula (1);
in the formula (1), K is the amplitude of the two sine wave modulation signals, theta is the phase difference of the two sine wave modulation signals, and P k Is the P coefficient, I, of the first PI controller k Is the I coefficient, P, of the first PI controller θ Is the P coefficient, I, of the second PI controller θ Is the I coefficient of the second PI controller.
9. The method of claim 8, wherein the step of decoupling the output power of the synchronous dual-band induction heating power supply comprises the steps of: in the step E; the control and modulation module generates two sine wave modulation signals SPWMA and SPWMB through an improved SPWM method to drive the full-bridge inverter to work and comprises the following steps:
the control and modulation module is also provided with an SPWM-A sine modulation wave generator and an SPWM-B sine modulation wave generator; the SPWM-A sine modulation wave generator is connected with the first PI controller to obtain the amplitude K and generate a first sine modulation wave signal SPWMA; the SPWM-B sine modulation wave generator is connected with the first PI controller and the second PI controller to obtain an amplitude K and a phase difference theta to generate a second sine modulation wave signal SPWMB;
the equations of the first sinusoidal modulated wave signal SPWMA and the second sinusoidal modulated wave signal SPWMB are as shown in equation (2):
f m is the intermediate frequency resonance frequency of the circuit;
the output end of the SPWM-A sine modulation wave generator is connected with a power switch tube S of the full-bridge inverter 1 The control terminal G of (2); the output end of the SPWM-A sine modulation wave generator is connected with a power switch tube S of a full-bridge inverter through a first inverter 2 The control terminal G of (2); the output end of the SPWM-B sine modulation wave generator is connected with a power switch tube S of the full-bridge inverter 3 The control terminal G of (2); the output end of the SPWM-B sine modulation wave generator is connected with a power switch tube S of a full-bridge inverter through a second inverter 4 The control terminal G of (1).
10. The decoupled regulation method for output power of a synchronous dual-band induction heating power supply of claim 1, characterized in that: the two sine wave modulation signals SPWMA and SPWMB are provided with carrier waves, the carrier waves are bipolar triangular waves CW, the amplitude value is a fixed value A, and the frequency is equal to the high-frequency resonant frequency of the circuit.
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