CN201976027U - Phase tracking circuit of induction heating power supply with inverse piezoelectric limiting effect on switching device - Google Patents
Phase tracking circuit of induction heating power supply with inverse piezoelectric limiting effect on switching device Download PDFInfo
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- CN201976027U CN201976027U CN201120062941XU CN201120062941U CN201976027U CN 201976027 U CN201976027 U CN 201976027U CN 201120062941X U CN201120062941X U CN 201120062941XU CN 201120062941 U CN201120062941 U CN 201120062941U CN 201976027 U CN201976027 U CN 201976027U
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Abstract
The utility model relates to a phase tracking circuit of an induction heating power supply with an inverse piezoelectric limiting effect on a switching device, belonging to the technical field of phase tracking for the induction heating power supply. In a PLL (phase locking loop) phase-locking tracking circuit, a inverse piezoelectric limiting circuit for the switching device is additionally arranged at the input end of a phase discriminator and behind a sampling device for an actual load voltage, a first shaping circuit, an adjustment delay device and a second shaping circuit. The inverse piezoelectric limiting circuit comprises a square wave signal formation circuit for the phase of the load voltage, a peak value sampling circuit and a PID (proportion, integration and differentiation) control circuit, wherein the square wave signal formation circuit can automatically adjust the delay, the peak value sampling circuit is used for sampling peak values of inverse voltages born by a diode connected in series with the switching device in the induction heating power supply. Therefore, the delay compensation time for square wave signals (u) of the phase of the load voltage can be adjusted automatically according to the inverse voltages, the phase difference between phase signals (u0) of the load voltage and switching and conversion phase signals (i0) of the switching device can be changed, the phase tracking feature can be improved, and the damage caused by the high inverse voltage of the load on the diode connected with the switching device in series can be avoided.
Description
Technical field
The utility model belongs to induction heating power inverter Phase Tracking control circuit field.
Background technology
Induction heating power has efficiency of heating surface height, quick heating, and controllability is good and be easy to realize be widely used advantages such as mechanization, automation in industries such as melting, casting, bend pipe, forge hot, welding and surface heat processing.
Fig. 1 is a parallel resonance induction heating power system block diagram, it mainly is made up of three parts: the rectification circuit that three-phase full-controlled rectifier bridge, sustained diode 0, reactor Ld constitute, three-phase main-frequency (50Hz) alternating current is changed continuous DC current source, and in order to realize the power adjustments of power supply; The single-phase inversion circuit that the fast recovery diode of 4 switching devices and series connection with it is formed, in order to realize that direct current is converted into alternating current sends into the parallel resonance load of being made up of Lf, Rf and Cf, wherein the purpose of fast recovery diode is that switching device bears the reverse voltage of loading oscillation circuit when turn-offing; Inverter control circuit is realized the Phase Tracking of load voltage phase signal u0 and switching device switch change of current phase signal i0, and for inverter switch device provides switching drive signal, wherein phase tracking circuit is the core of whole power supply.
Traditional Phase Tracking technology mainly is the PLL phase-locked loop circuit that is made of the CD4046 integrated phase lock, comprises the passive low ventilating filter LPF that phase discriminator PD, voltage controlled oscillator VCO and external R, C constitute, as shown in Figure 2.The basic functional principle of phase-locked loop circuit is by the phase difference between comparator input signal and the voltage controlled oscillator output signal, regulate the VCO output frequency and reach input, the synchronous purpose of output signal, conventional phase locked loops phase tracking circuit waveform correlation figure as shown in Figure 3.
Among Fig. 2 and Fig. 3, u0 is the actual load voltage phase signal, and u0 produces time-delay d1 through the sampling shaping circuit, obtains square-wave signal u1.U1 adjusts time-delay through RC and produces compensation of delay d2, obtains load voltage phase place square-wave signal u, and u and u ' are same signal in the conventional phase locked loops phase tracking circuit, as the road input of phase discriminator PD.
I0 is a switching device switch change of current phase signal, can be replaced by the switching device switching drive signal i1 of VCO output, and d0 is the switching device switch change of current time, just the actual time delay difference between i1 and the i0.I1 adjusts time-delay through RC and produces compensation of delay d3, obtains switching device switch change of current current phase square-wave signal i, as another road input of phase discriminator PD.
Because the phase-locked effect of PLL phase-locked loop circuit makes two square-wave signals of u (or u ') and i keep same-phase, phase difference is zero.D4 then is the time interval between the zero crossing of the zero crossing of u0 and i0, i.e. phase difference between u0 and the i0, obviously d4=(d3-d2)-d1-d0.
For the people is R1, the R2 that adjusts, and then d2, d3 are changeless during power work, so the size of d4 is by d0 and d1 decision.If d4=0, loaded work piece is at the quasi-resonance state, and switching device can be realized under zero-current switching (ZCS) and the minimum voltage open-minded; If d4＜0, loaded work piece are perceptual state (zero crossing of i0 lags behind the zero crossing of u0), flowing out the phase switching device this moment is hard the shutoff, and because there is lead-in inductance in the loop, produces a peak voltage when switching device is turn-offed; If d4＞0, loaded work piece is capacitive state (zero crossing of i0 is ahead of the zero crossing of u0), voltage was higher when flowed into the conducting of phase switching device this moment, the conducting impulse current is arranged, can bear back-pressure after the change of current of switching device diode in series mutually with outflow simultaneously, back-pressure is big more, and reverse recovery current is big more, and the diode power consumption is also big more.
For above-mentioned phase tracking circuit,, regulate R1 and R2 generally speaking, make that load is weak capacitive under typical condition in order to prevent the induction heating power loaded work piece at perceptual state.But under some operating mode, for example, when loaded work piece voltage raise, the value of switching device switch change of current time d0 and shaping circuit time-delay d1 all can reduce; Along with the rising of heating-up temperature, load impedance can increase, and load current reduces, and the d0 value also can reduce.Therefore, the comprehensive function of the factors such as variation of load impedance, operating frequency and operating voltage amplitude causes the d4 value to increase, thereby causes that loaded work piece capacitive state increases, and the back-pressure on the series diode is excessive, causes diode to damage easily.
The utility model content
The purpose of this utility model provides an induction heating power phase tracking circuit with switching device back-pressure limitation function.
Of the present utility model being characterised in that contained: the voltage-phase sample circuit of actual load voltage phase signal (u0), first shaping circuit (IC1), by first variable resistor (R1), the first adjustment delay circuit that first electric capacity (C1) and the 5th diode (D5) constitute, second shaping circuit (IC2), phase discriminator (PD), low-pass filter circuit (LPF) by the 3rd resistance (R3) and the 3rd electric capacity (C3) formation, voltage controlled oscillator (VCO), overlapping time generative circuit, adjust delay circuit by second of the second adjustable resistance (R2) and second electric capacity (C2) and the 6th diode (D6) formation, the 3rd shaping circuit (IC3) and two isolated drive circuits, wherein: actual load voltage phase place square-wave signal (u0) passes through described voltage-phase sample circuit successively, first shaping circuit (IC1), first adjusts delay circuit, behind second shaping circuit (IC2), constitute first input signal of phase discriminator (PD); By the switching device switching drive signal (i1) in the described induction heating power of described generative circuit output overlapping time, through behind the described second adjustment delay circuit, the 3rd shaping circuit (IC3), constitute second input signal of phase discriminator (PD) successively;
It is characterized in that, between described second shaping circuit (IC2) output and phase discriminator (PD) input, a switching device back-pressure restricting circuits is gone in series connection, this back-pressure restricting circuits contains: and the load voltage phase place square-wave signal of automatic adjustment time-delay (u ') the formation circuit, the peak value sampling circuit and the PID control circuit of the reverse voltage (ud) that switching device institute diode in series is born, the load voltage phase place square-wave signal (u ') of wherein automatically adjusting time-delay forms circuit and contains: Chuan Jie the 4th shaping circuit (IC4A) successively, by the 4th variable resistor (R4), the ramp waveform generation circuit that the 4th electric capacity (C4) and the 7th diode (D7) constitute, first comparator (IC5A), the 5th shaping circuit (IC4B), wherein:
The 4th shaping circuit (IC4A), load voltage phase place square-wave signal (u) are connected to two inputs of the 4th shaping circuit simultaneously;
Ramp waveform generation circuit, one end of the 4th variable resistor (R4) is through the 4th electric capacity (C4) ground connection, link to each other with the sliding contact of the 4th variable resistor (R4) again simultaneously, after forward connects one the 7th diode (D7) again simultaneously, link to each other with the output of described the 4th shaping circuit (IC4A);
First comparator (IC5A) positive input terminal links to each other with the output of described ramp waveform generation circuit, the output of first comparator (IC5A) through with the 5th resistance (R5) positive feedback after receive the positive input terminal of described first comparator (IC5A), the output of first comparator (IC5A) connects+the 15V power supply through the 6th resistance (R6) simultaneously, outputs to two inputs of described the 5th shaping circuit (IC4B) again;
The 5th shaping circuit (IC4B), output are through the load voltage phase place square-wave signal of automatically adjusting time-delay (u ');
The peak value sampling circuit contains: transformer (YH4), first negative feedback amplifier (U1), sampled signal that output is connected to a resistor voltage divider circuit form circuit and second negative feedback amplifier (U2), wherein:
Transformer (YH4), input are the reverse voltages that described switching device series diode bears;
First negative feedback amplifier (U1), positive input terminal links to each other with the output of described resistor voltage divider circuit, and output forward series connection one the 8th diode (D8);
Sampled signal forms circuit and contains: monostable flipflop (IC6A) and transistor switching circuit, wherein:
Monostable flipflop (IC6A), first input end connects the differential circuit of usefulness the 11 variable resistor (R11) and the 9th electric capacity (C9) composition, second input connects 2 frequency multiplication switching drive signals (2F) of described switching device switching drive signal (i1), the output of described monostable flipflop (IC6A) connects one by-15V power supply power supply, behind the mid point of the bleeder circuit that forms with the 9th diode (D9) of the 13 resistance (R13), differential concatenation series connection ground connection, link to each other with the base stage of triode (G1) in the described transistor switching circuit;
Transistor switching circuit, by a grounded emitter, the triode (G1) that collector electrode connects the 14 resistance (R14), the 5th electric capacity (C5) back ground connection successively constitutes, the tie point of described the 14 resistance (R14), the 5th electric capacity (C5) is connected to the negative pole of described the 8th diode (D8) simultaneously, with the positive pole of second negative feedback amplifier (U2), described tie point is connected to the 15 resistance (R15) over the ground;
The PID control circuit contains: the 3rd negative feedback amplifier (U3), the 4th negative feedback amplifier (U4), positive clamping circuit and back clamping circuit, wherein:
The 3rd negative feedback amplifier (U3), positive input terminal ground connection, negative input end connect a mid point by-15V power supply through the 16 variable resistor (R16) power supply, the output of the variable bleeder circuit of first capacitance-resistance that is in series with the 7th electric capacity (C7), the 17 resistance (R17), the other end ground connection of the 7th electric capacity (C7), this negative input end are received the output of described second negative feedback amplifier (U2) simultaneously through the 18 resistance (R18);
The 4th negative feedback amplifier (U4), positive input terminal ground connection, negative input end connects the output of described the 3rd negative feedback amplifier (U3) behind the 19 resistance (R19);
Positive clamping circuit, contain: the voltage-stabiliser tube of plus earth (Z1), with the tenth diode (D10) that negative pole links to each other with described voltage-stabiliser tube (Z1) negative pole, the negative pole of this voltage-stabiliser tube links to each other through the output of the 20 resistance (R20) with described the 4th negative feedback amplifier (U4);
The back clamping circuit, be in series by the 22 resistance (R22) and the 21 resistance (R21) parallel with one another and the 8th electric capacity (C8) and form, the tie point of this back clamping circuit is received the negative pole of described the tenth diode (D10), one end ground connection of the 8th electric capacity (C8), this back clamping circuit voltage that dividing potential drop is later is received the negative input end of described first comparator (IC5A) simultaneously.
Description of drawings
Fig. 1 parallel resonance induction heating power system block diagram, wherein u0 is the actual load voltage phase signal, i0 is a switching device switch change of current phase signal, the reverse voltage that fast diode bore of ud for connecting with switching device;
Fig. 2 phase-locked loop phase tracking circuit theory diagram;
Fig. 3 conventional phase locked loops phase tracking circuit waveform correlation figure, u1 wherein, u, i1, i only express the rising edge of waveform;
Fig. 4 circuit theory diagrams of the present utility model, wherein u is the load voltage phase place square-wave signal of switching device back-pressure restricting circuits input, u ' is the load voltage phase place square-wave signal of switching device back-pressure restricting circuits output, the reverse voltage that ud bears for the switching device series diode;
Inverter load voltage and load current waveform under the traditional Phase Tracking technical situation of Fig. 5, u0:500V/ lattice among the figure; The i0:200A/ lattice; The t:5us/ lattice;
Inverter load voltage and load current waveform under the improved Phase Tracking technical situation of Fig. 6, u0:500V/ lattice among the figure; The i0:200A/ lattice; The t:5us/ lattice.
Effect proves
Compared and can clearly be found out by Fig. 5 and Fig. 6, improved Phase Tracking technology has suppressed the back-pressure value that the switching device series diode bears effectively, has reduced the reverse recovery current of diode, has reduced the diode power consumption, has reached the purpose of back-pressure restriction.
Embodiment
Improved phase tracking circuit is based on original PLL phase-locked loop Phase Tracking technology, adds switching device back-pressure restricting circuits.Promptly in the sampling of existing actual load voltage phase signal u0, shaping, delay circuit, add a back-pressure value size of bearing according to the switching device series diode, the link (G as shown in schematic diagram among Fig. 2) of automatic regulation voltage phase place square-wave signal time-delay, compensation of delay time d2 to u0 adjusts automatically, thereby change the phase difference d4 between u0 and the i0, reach the purpose of improving the Phase Tracking characteristic.
Fig. 4 is the circuit diagram of switching device back-pressure restricting circuits, and wherein u is the square-wave signal of switching device back-pressure restricting circuits input, and u ' is the square-wave signal of switching device back-pressure restricting circuits output, the reverse voltage that ud bears for the switching device series diode.The operation principle of switching device back-pressure restricting circuits is as follows: the peak value of back voltage sample circuit that the switching device series diode bears, the peak signal of reverse voltage ud is sent into switching device back-pressure restricting circuits.This signal compares with the back-pressure value that sets, and the gained error is regulated the back through the PID control circuit and formed a level signal, sends into the negative input end of comparator IC5A.Square-wave signal u is through the IC4A shaping simultaneously, the ramp waveform generation circuit of sending into R4, C4, D7 composition makes the square-wave waveform rising edge slow down, send into the positive input terminal of comparator IC5A, with the level signal of PID control circuit output relatively after, form new process and adjust the square-wave signal u ' of time-delay automatically, the phase discriminator (PD) of PLL phase-locked loop phase tracking circuit is sent in output.
If actual back-pressure value ud is during less than the back-pressure set point, the error level is zero, and switching device back-pressure restricting circuits makes u ' not produce time-delay; Otherwise the square-wave signal u ' of comparator output can produce certain delay, and along with the variation of reverse voltage value, switching device back-pressure restricting circuits is adjusted the size of inserting delay value automatically.The time-delay that increases voltage-phase u is equivalent to increase d1, thereby reduces d4, thereby makes power load circuit be operated in weak capacitive state, has effectively limited back-pressure ud.
Claims (1)
1. the induction heating power phase tracking circuit that has switching device back-pressure limitation function, contain: the voltage-phase sample circuit of actual load voltage phase signal (u0), first shaping circuit (IC1), by first variable resistor (R1), the first adjustment delay circuit that first electric capacity (C1) and the 5th diode (D5) constitute, second shaping circuit (IC2), phase discriminator (PD), low-pass filter circuit (LPF) by the 3rd resistance (R3) and the 3rd electric capacity (C3) formation, voltage controlled oscillator (VCO), overlapping time generative circuit, adjust delay circuit by second of the second adjustable resistance (R2) and second electric capacity (C2) and the 6th diode (D6) formation, the 3rd shaping circuit (IC3) and two isolated drive circuits, wherein: actual load voltage phase place square-wave signal (u0) passes through described voltage-phase sample circuit successively, first shaping circuit (IC1), first adjusts delay circuit, behind second shaping circuit (IC2), constitute first input signal of phase discriminator (PD); By the switching device switching drive signal (i1) in the described induction heating power of described generative circuit output overlapping time, through behind the described second adjustment delay circuit, the 3rd shaping circuit (IC3), constitute second input signal of phase discriminator (PD) successively;
It is characterized in that, between described second shaping circuit (IC2) output and phase discriminator (PD) input, a switching device back-pressure restricting circuits is gone in series connection, this back-pressure restricting circuits contains: and the load voltage phase place square-wave signal of automatic adjustment time-delay (u ') the formation circuit, the peak value sampling circuit and the PIfD control circuit of the reverse voltage (ud) that switching device institute diode in series is born, the load voltage phase place square-wave signal (u ') of wherein automatically adjusting time-delay forms circuit and contains: Chuan Jie the 4th shaping circuit (IC4A) successively, by the 4th variable resistor (R4), the ramp waveform generation circuit that the 4th electric capacity (C4) and the 7th diode (D7) constitute, first comparator (IC5A), the 5th shaping circuit (IC4B), wherein:
The 4th shaping circuit (IC4A), load voltage phase place square-wave signal (u) are connected to two inputs of the 4th shaping circuit simultaneously;
Ramp waveform generation circuit, one end of the 4th variable resistor (R4) is through the 4th electric capacity (C4) ground connection, link to each other with the sliding contact of the 4th variable resistor (R4) again simultaneously, after forward connects one the 7th diode (D7) again simultaneously, link to each other with the output of described the 4th shaping circuit (IC4A);
First comparator (IC5A) positive input terminal links to each other with the output of described ramp waveform generation circuit, the output of first comparator (IC5A) through with the 5th resistance (R5) positive feedback after receive the positive input terminal of described first comparator (IC5A), the output of first comparator (IC5A) connects+the 15V power supply through the 6th resistance (R6) simultaneously, outputs to two inputs of described the 5th shaping circuit (IC4B) again;
The 5th shaping circuit (IC4B), output are through the load voltage phase place square-wave signal of automatically adjusting time-delay (u ');
The peak value sampling circuit contains: transformer (YH4), first negative feedback amplifier (U1), sampled signal that output is connected to a resistor voltage divider circuit form circuit and second negative feedback amplifier (U2), wherein:
Transformer (YH4), input are the reverse voltages that described switching device series diode bears;
First negative feedback amplifier (U1), positive input terminal links to each other with the output of described resistor voltage divider circuit, and output forward series connection one the 8th diode (D8);
Sampled signal forms circuit and contains: monostable flipflop (IC6A) and transistor switching circuit, wherein:
Monostable flipflop (IC6A), first input end connects the differential circuit of usefulness the 11 variable resistor (R11) and the 9th electric capacity (C9) composition, second input connects 2 frequency multiplication switching drive signals (2F) of described switching device switching drive signal (i1), the output of described monostable flipflop (IC6A) connects one by-15V power supply power supply, behind the mid point of the bleeder circuit that forms with the 9th diode (D9) of the 13 resistance (R13), differential concatenation series connection ground connection, link to each other with the base stage of triode (G1) in the described transistor switching circuit;
Transistor switching circuit, by a grounded emitter, the triode (G1) that collector electrode connects the 14 resistance (R14), the 5th electric capacity (C5) back ground connection successively constitutes, the tie point of described the 14 resistance (R14), the 5th electric capacity (C5) is connected to the negative pole of described the 8th diode (D8) simultaneously, with the positive pole of second negative feedback amplifier (U2), described tie point is connected to the 15 resistance (R15) over the ground;
The PID control circuit contains: the 3rd negative feedback amplifier (U3), the 4th negative feedback amplifier (U4), positive clamping circuit and back clamping circuit, wherein:
The 3rd negative feedback amplifier (U3), positive input terminal ground connection, negative input end connect a mid point by-15V power supply through the 16 variable resistor (R16) power supply, the output of the variable bleeder circuit of first capacitance-resistance that is in series with the 7th electric capacity (C7), the 17 resistance (R17), the other end ground connection of the 7th electric capacity (C7), this negative input end are received the output of described second negative feedback amplifier (U2) simultaneously through the 18 resistance (R18);
The 4th negative feedback amplifier (U4), positive input terminal ground connection, negative input end connects the output of described the 3rd negative feedback amplifier (U3) behind the 19 resistance (R19);
Positive clamping circuit, contain: the voltage-stabiliser tube of plus earth (Z1), with the tenth diode (D10) that negative pole links to each other with described voltage-stabiliser tube (Z1) negative pole, the negative pole of this voltage-stabiliser tube links to each other through the output of the 20 resistance (R20) with described the 4th negative feedback amplifier (U4);
The back clamping circuit, be in series by the 22 resistance (R22) and the 21 resistance (R21) parallel with one another and the 8th electric capacity (C8) and form, the tie point of this back clamping circuit is received the negative pole of described the tenth diode (D10), one end ground connection of the 8th electric capacity (C8), this back clamping circuit voltage that dividing potential drop is later is received the negative input end of described first comparator (IC5A) simultaneously.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201120062941XU CN201976027U (en) | 2011-03-10 | 2011-03-10 | Phase tracking circuit of induction heating power supply with inverse piezoelectric limiting effect on switching device |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201120062941XU CN201976027U (en) | 2011-03-10 | 2011-03-10 | Phase tracking circuit of induction heating power supply with inverse piezoelectric limiting effect on switching device |
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| CN201976027U true CN201976027U (en) | 2011-09-14 |
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| CN201120062941XU Expired - Lifetime CN201976027U (en) | 2011-03-10 | 2011-03-10 | Phase tracking circuit of induction heating power supply with inverse piezoelectric limiting effect on switching device |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103312204A (en) * | 2012-03-17 | 2013-09-18 | 丰郅(上海)新能源科技有限公司 | Inverter topology with wide input voltage range |
| CN104104220A (en) * | 2013-04-08 | 2014-10-15 | 广东美的制冷设备有限公司 | Intelligent power module |
| CN109587602A (en) * | 2017-09-29 | 2019-04-05 | 深圳市三诺数字科技有限公司 | A kind of audio signal boost control circuit |
-
2011
- 2011-03-10 CN CN201120062941XU patent/CN201976027U/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103312204A (en) * | 2012-03-17 | 2013-09-18 | 丰郅(上海)新能源科技有限公司 | Inverter topology with wide input voltage range |
| CN104104220A (en) * | 2013-04-08 | 2014-10-15 | 广东美的制冷设备有限公司 | Intelligent power module |
| CN104104220B (en) * | 2013-04-08 | 2016-12-28 | 广东美的制冷设备有限公司 | A kind of SPM |
| CN109587602A (en) * | 2017-09-29 | 2019-04-05 | 深圳市三诺数字科技有限公司 | A kind of audio signal boost control circuit |
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