CN102324855B - Special AC (alternate current) adjustable power supply for carrying out power measurement and control method thereof - Google Patents
Special AC (alternate current) adjustable power supply for carrying out power measurement and control method thereof Download PDFInfo
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Abstract
The invention relates to an AC/AC (alternate current) power conversion device of a semiconductor device to which a control electrode is applied, in particular to a power conversion device which is controlled by a microprocessor and is used for providing a linear adjustable sinusoidal AC voltage and a linear adjustable sinusoidal alternate current for a portable power electronic measuring instrument and a microprocessor program control method for a special AC adjustable power supply for carrying out power measurement. The special AC adjustable power supply for carrying out power measurement comprises a switching converter unit, an input sampling unit, an output sampling unit, a control unit and a driving unit. The switching converter unit is connected between an AC power supply and an AC load. Four switching devices with the control electrodes and four diodes are adopted in the switching converter unit. The switching devices share one group of filter inductances and filter capacitors. The switching converter unit is connected to the control unit through the input sampling unit and the output sampling unit. The control unit is connected to the control electrodes of the four switching devices through the driving unit.
Description
Technical field
The present invention relates to a kind of application has the AC/AC electric power conversion apparatus of the semiconductor device of controlling the utmost point, and what relate in particular to that a kind of microprocessor controls provides linear adjustable sinusoidal voltage and the electric power conversion apparatus of electric current for portable power electronic measuring instrument.
Background technology
Power measurement will be simulated the service conditions at power supply and electricity consumption scene, and linear adjustable sinusoidal voltage and electric current often will be provided on its measuring instrument.Existing AC/DC/DC/AC mode need to be used transformer conventionally, and the capacity of transformer must meet the requirement of power output, the power supply of electric power measuring device needs the power output of 3-10kw conventionally, not only weight is very large can to meet the transformer of demanded power output of 3-10kw, and manufacture transformer and need to consume a large amount of non-ferrous metals and electrical sheet, its manufacturing cost is also very high.The realization of employing AC/AC converting means is boosted or step-down pressure regulation is a kind of conventional method.Chinese invention patent " two buck/boost two-way AC chopper " (Chinese invention patent ZL200610096870.9 patent of invention publication number CN1967993) discloses a kind of pair of buck/boost two-way AC chopper, comprise that the filter capacitor power circuit that form in parallel with AC sinusoidal voltage power supply by one end ground connection also comprises a buck/boost circuit and the 2nd buck/boost circuit, this invention has solved electric current commutation problem, can realize step-down or the AC/AC that boosts conversion.But, because the technical scheme of this invention obtains by two DC/DC basic topologies (buck/boost circuit) are carried out to parallel connection, be subject to the impact of buck/boost circuit structure, its circuit structure, especially its control circuit more complicated.
Summary of the invention
The object of the invention is will be provided for exchanging the microprocessor program control method of adjustable power measurement power source special, solve the technical problem of AC/AC supply convertor switching device change of current control circuit complexity.
The present invention solves the problems of the technologies described above adopted technical scheme:
For exchanging an AC/AC supply convertor switching device change of current control method for adjustable power measurement power source special, comprise following steps:
S100) call AD conversion routine and output voltage is carried out to the step of digital-to-analogue conversion sampling input;
S200) step that the reference voltage that calls AD conversion routine output voltage regulating element is provided carries out digital-to-analogue conversion;
S300), according to reference voltage and output voltage, use Digital PID Algorithm to determine the step of duty ratio;
S400) according to duty ratio, set the step of the timing value of PWM output unit;
S500) detect the step of voltage and current zero passage flag bit, utilize rise/fall along capture interrupt program, the phase place of judgement voltage and current; Described rise/fall comprises following action along catching interrupt routine:
S520) judgement rise/fall is along the step that catches interrupt source;
S540) judgement rise/fall is along the step of trap state;
S560) according to interrupt source and rise/fall along trap state, the step of voltage and current zero passage flag bit is set;
S580) revise the step of rising edge/trailing edge trap mode;
Wherein, described voltage and current zero passage flag bit comprises voltage drop zero passage flag bit, voltage rising zero passage flag bit, electric current decline zero passage flag bit and Current rise zero passage flag bit;
S600) judgement voltage and current zero passage flag bit, calls the step that switching device state is controlled subprogram, and this step comprises following action:
If electric current decline zero passage flag bit be 1 and voltage rising zero passage flag bit be 1, call switching device state and control subprogram S620, return to step S100 cyclical execution of programs;
If Current rise zero passage flag bit be 1 and voltage rising zero passage flag bit be 1, call switching device state and control subprogram S640, return to step S100 cyclical execution of programs;
If Current rise zero passage flag bit be 1 and voltage drop zero passage flag bit be 1, call switching device state and control subprogram S660, return to step S100 cyclical execution of programs;
If electric current decline zero passage flag bit be 1 and voltage drop zero passage flag bit be 1, call switching device state and control subprogram S680, return to step S100 cyclical execution of programs;
Described switching device state is controlled subprogram and is comprised following steps:
S620) make the first output of PWM output unit keep low level; Make the second output of PWM output unit keep high level; Make the 3rd output of PWM output unit keep high level; Make the 4th output of PWM output unit according to the definite duty ratio output PWM chopping signal of step S300; Return to main program;
S640) make the first output of PWM output unit according to the definite duty ratio output PWM chopping signal of step S300; Make the second output of PWM output unit keep high level: to make the 3rd output of PWM output unit keep high level; Make the 4th output of PWM output unit keep low level; Return to main program;
S660) make the first output of PWM output unit keep high level; Make the second output of PWM output unit keep low level; Make the 3rd output of PWM output unit according to the definite duty ratio output PWM chopping signal of step S300; Make the 4th output of PWM output unit keep low level; Return to main program;
S680) make the first output of PWM output unit keep high level; Make the second output of PWM output unit according to the definite duty ratio output PWM chopping signal of step S300; Make the 3rd output of PWM output unit keep high level; Make the 4th output of PWM output unit keep low level; Return to main program.
A kind of preferably technical scheme of AC/AC supply convertor switching device change of current control method of the present invention is that AD conversion routine comprises the step of AD conversion sampling input data being carried out to Digital smooth filtering.
The further improved technical scheme of AC/AC supply convertor switching device change of current control method of the present invention is that described microprocessor program control method also comprises the step of carrying out overvoltage judgement and overvoltage protection action; if output voltage surpasses default overvoltage protection reference value, control switch device is cut off the electricity supply.
Another object of the present invention is the adjustable power measurement power source special of simple and reliable interchange that will provide a kind of microprocessor to control, use above-mentioned AC/AC supply convertor switching device change of current control method, with new simple and reliable circuit structure, solve the technical problem of AC/AC power conversion, adjustable sinusoidal voltage and the electric current of the stable output providing for power measuring instrument.
The present invention solves the problems of the technologies described above adopted technical scheme:
A kind of adjustable power measurement power source special of interchange that uses above-mentioned microprocessor program control method, comprise switch convertor unit, input sample unit, output sampling unit, control unit and driver element, described switch convertor unit is connected between AC power and AC load.Described switch convertor unit adopts 4 to have switching device and 4 diodes of controlling the utmost point, forms the class Buck-Boost circuit that comprises mirror image brachium pontis; The switching device of described Buck-Boost circuit shares one group of filter inductance and filter capacitor.The anode of 4 diodes and negative electrode be negative electrode and the anode of 4 switching devices of reverse parallel connection to first to fourth respectively; The anode of the first switching device and second switch device forms the input of switch convertor unit, is connected respectively to the two ends of input ac power; The negative electrode of the 3rd switching device and the 4th switching device is connected respectively to the two ends of filter capacitor, forms the output of switch convertor unit, is connected respectively to the two ends of output AC load; The negative electrode of the first switching device is connected to one end of anode and the filter inductance element of the 3rd switching device, and the negative electrode of second switch device is connected to the anode of the 4th switching device and the other end of filter inductance element.Described switch convertor unit is connected to and described control unit by described input sample unit and output sampling unit; Described control unit is connected to the control utmost point of described 4 switching devices by described driver element.
A kind of preferably technical scheme of interchange of the present invention is adjustable power measurement power source special is that described control unit adopts microprocessor program control unit, comprises memory, IO interface circuit, AD converter and the PWM output unit of microprocessor, storage data and the control program of executive control program; The input of described control unit comprises digital signal input end and input end of analog signal, described digital signal input end is connected to microprocessor by IO interface circuit, described input end of analog signal is connected to microprocessor by AD converter, wherein has at least an input end of analog signal to be connected with output voltage regulating element; Described PWM output unit at least comprises 4 road PWM modules, and microprocessor connects described driver element by PWM module.
A kind of better technical scheme of interchange of the present invention is adjustable power measurement power source special is that described output sampling unit comprises voltage sampling circuit and voltage zero-crossing detection circuit; The input of voltage sampling circuit is connected to the output of described switch convertor unit, and the output of voltage sampling circuit is connected to the input end of analog signal of described control unit; The output of switch convertor unit is connected to the digital signal input end of described control unit by voltage zero-crossing detection circuit.
The better technical scheme of another kind of interchange of the present invention is adjustable power measurement power source special is that described current sampling unit comprises current sampling circuit and current over-zero testing circuit; Current sampling circuit is connected on the input of described switch convertor unit, and the output of current sampling circuit is connected to the digital signal input end of described control unit by current over-zero testing circuit.
A kind of improved technical scheme of interchange of the present invention is adjustable power measurement power source special is that the external signal that the output of described voltage zero-crossing detection circuit and current over-zero testing circuit is connected to described microprocessor is caught input, and microprocessor utilizes rise/fall along the phase place of catching judgement voltage and current.
The further improved technical scheme of interchange of the present invention is adjustable power measurement power source special is that described driver element comprises high-pressure side suspension drive circuit and optic coupling element, and the output of described control unit is connected to the control utmost point of described switching device after by optic coupling element and the isolation of high-pressure side suspension drive circuit two-stage.
The invention has the beneficial effects as follows:
Interchange of the present invention is adjustable, and power measurement power source special adopts fully-controlled type switching device topological structure, and output does not adopt output transformer, adapts to perceptual load long-pending little lightweight, does not consume non-ferrous metal, is particularly suitable for portable equipment and uses.Interchange of the present invention is adjustable, and power measurement power source special can be used for the inductive load of large electric current, has good reliability and good sinusoidal waveform.
Share one group of filter inductance and filter capacitor, compare with disclosed pair of buck/boost two-way AC chopper of prior art, omitted one group of filter inductance and filter capacitor, make circuit topological structure simpler.The present invention is changed and is omitted by circuit key element, on the basis of improving reliability and reducing costs, has kept the repertoire of prior art scheme.Because filter inductance and filter capacitor element are operated in the operating state of high voltage, high-frequency, large electric current in AC/AC translation circuit, omit filter inductance and filter capacitor and not only can reduce costs, can also improve reliability.
By the method that adopts microprocessor program to control, solve the technical problem of AC/AC supply convertor switching device change of current control circuit complexity, according to the in good time control switch device of the phase difference of voltage and current, make its conducting and closing on request in sine wave period, by change in duty cycle, realize pressure regulation, make sinusoidal voltage and electric current that supply convertor can stable output in certain input voltage range, when simplifying circuit hardware structure, meet the requirement to adjustable ac source stability and reliability of electric power measuring device and other field.
Accompanying drawing explanation
Fig. 1 is the topological structure electrical schematic diagram of the adjustable power measurement power source special of interchange of the present invention;
Fig. 2 is switching device drive signal waveform figure;
Fig. 3 is the working state schematic representation of the switch convertor unit of class Buck-Boost circuit;
Fig. 4 is the electrical schematic diagram of the microprocessor program control unit of the adjustable power measurement power source special of interchange of the present invention;
Fig. 5 is the electrical schematic diagram of voltage zero-crossing detection circuit;
Fig. 6 is the oscillogram of voltage zero-crossing detection circuit;
Fig. 7 is the electrical schematic diagram of current sampling circuit and current over-zero testing circuit;
Fig. 8 is the oscillogram of current sampling circuit and current over-zero testing circuit;
Fig. 9 is the timing waveform figure that timer interrupts producing adjustable PWM.
Figure 10 is the electrical schematic diagram of driver element;
Figure 11 is the main program flow chart of microprocessor program control method of the present invention;
Figure 12 is the flow chart that switching device state is controlled subprogram;
Figure 13 is the flow chart of AD conversion routine;
Figure 14 is that zero passage detection rise/fall is along the flow chart that catches interrupt routine.
Embodiment
In order to understand better technique scheme of the present invention, below in conjunction with drawings and Examples, describe in detail further.
Fig. 1 is the topological structure electrical schematic diagram of an embodiment of the adjustable power measurement power source special of interchange of the present invention, comprise switch convertor unit 10, input sample unit 20, output sampling unit 30, control unit 40 and driver element 50, switch convertor unit 10 is connected between AC power AC and AC load, switch convertor unit adopts 4 to have switching device and 4 diodes of controlling the utmost point, forms the class Buck-Boost circuit that comprises mirror image brachium pontis; The switching device S1 to S4 of class Buck-Boost circuit shares one group of filter inductance L and filter capacitor C; The anode of 4 diodes and negative electrode be negative electrode and the anode of 4 switching device S1 to S4 of reverse parallel connection to first to fourth respectively; The anode of the first switching device S1 and second switch device S2 forms the input of switch convertor unit 10, is connected respectively to the two ends of input ac power AC; The negative electrode of the 3rd switching device S3 and the 4th switching device S4 is connected respectively to the two ends of filter capacitor C, forms the output of switch convertor unit 10, is connected respectively to the two ends of output AC load; The negative electrode of the first switching device S1 is connected to one end of anode and the filter inductance element L of the 3rd switching device S3, and the negative electrode of second switch device S2 is connected to the anode of the 4th switching device S4 and the other end of filter inductance element L.Switch convertor unit 10 is connected to and control unit 40 by input sample unit 20 and output sampling unit 30; Control unit 40 is connected to the control utmost point of 4 switching devices by driver element 50.
In the present embodiment, S1, S2, S3, S4 adopt four IGBT(insulated gate bipolar transistors), wherein S1, S3 also can form by an IGBT module of connecting respectively with S2, S4.Equally, 4 switching devices also can adopt the semiconductor switch device of power MOSFET or other control pole cut-off.The anode of switching device is corresponding to the collector electrode of IGBT or the drain electrode of MOSFET in the present invention, and negative electrode, corresponding to the emitter of IGBT or the source electrode of MOSFET, is controlled the utmost point corresponding to gate pole or the grid of IGBT or MOSFET.
Structure shown in Fig. 1 is similar to carries out mirror image by buck Buck-Boost circuit, increases a brachium pontis, the diode in Buck-Boost is used the switching device with anti-paralleled diode to substitute simultaneously, is referred to as in the present invention class Buck-Boost circuit.The difficult point that this structure realizes is the Commutation Problem when alternating voltage zero-crossing, and in order to address this problem, can sample input Vi and output voltage V o, when Vi > Vo, make S2, S4 often open, S1, the complementation of S3 high frequency.When Vi < Vo, S1, S3 often open, S2, the complementation of S4 high frequency.The switching drive signal of switching device as shown in Figure 2.T0 to t1 during this period of time in, S2 and S4 often open, the electric current I on inductance
lmay be greater than zero and also may be less than zero.Work as I
l> 0, and when S1 opens, electric current is through the anti-paralleled diode circulation of S1 and S2, and inductance L energy storage, as shown in Fig. 3 (a); When S1 closes, electric current releases energy to load through the anti-paralleled diode of S4 and S3, as shown in Fig. 3 (b); Work as I
l< 0, when S3 closes, electric current through the anti-paralleled diode of S2 and S1 to power supply feedback energy, as shown in Fig. 3 (c): when S3 opens, electric current releases energy to load through the anti-paralleled diode of S3 and S4, as shown in Fig. 3 (d).T1 can similar analysis obtain to the course of work of t2 period circuit.
When circuit working is in the situation that duty ratio D is greater than 0.5, this circuit can be realized boost function, and when duty ratio is less than 0.5, circuit can be realized buck functionality.By output voltage is carried out to sampling feedback control, the duty ratio of control circuit work, just can provide stable adjustable sine-wave power output.
Suppose that switching tube is ideal element, can transient switching and cut-off, and also pressure drop is zero during conducting, during cut-off, leakage current is zero; Inductance, electric capacity are ideal elements; Ripple voltage in output voltage and the ratio of output voltage are little to be ignored to allowing.In a switch periods, the sinusoidal voltage of input can be similar to thinks direct voltage, according to the operation principle of Buck-Boost, and the relation of input voltage and output voltage:
Wherein uo, ui are respectively input voltage and an output voltage in switch periods, and D is duty ratio.From a complete power frequency period, the relation of input voltage effective value and output voltage effective value also meets:
Therefore, at input voltage Vi, in unstable or load variations, only needing to change a duty ratio D can regulated output voltage Vo.The selection of filter inductance L and filter capacitor C can obtain by designing and calculating with reference to prior art Buck-Boost circuit parameter.
As shown in Figure 4, control unit 10 adopts microprocessor program control units to a preferred embodiment of the control unit 40 of interchange of the present invention is adjustable power measurement power source special.In the present embodiment, adopt STC12C5412AD single-chip microcomputer IC1 as control chip, chip internal is integrated memory, IO interface circuit, AD converter, timer and the 4 passage capture compare unit (PCA module) of the microprocessor of executive control program, storage data and control program.3 end pressurizer U1 provide 5V single-chip microcomputer operating voltage, and ZD1, ZD2 and ZD3 are that 5.1V voltage-stabiliser tube is for the protection of single-chip microcomputer.
Digital signal input end is connected to microprocessor by IO interface circuit, and input end of analog signal is connected to microprocessor by AD converter, forms digital signal input end and the input end of analog signal of control unit 10.
Single-chip microcomputer P1.2, P1.3 are operated in high-impedance state, as AD conversion input.Output voltage regulating element W1 is connected to the input P1.3 of AD converter.Output voltage regulating element W1 is the potentiometer for regulation output voltage, can produce the direct voltage of 0～5V, converts the heuristicimal code of 00～1FF to as pressure regulation benchmark by AD.In output sampling unit, adopt voltage sensor to sample to output voltage, the direct voltage that voltage sensor is 0～5V by 0～250V AC voltage conversion.The output of voltage sensor is connected to the input DV of control unit, again by after RC filter circuit filtering High-frequency Interference, be connected to the input P1.2 of AD converter, sampled voltage is sent into microprocessor and do mean value calculation, and do computing with the output voltage that voltage-regulation element W1 sets, obtain the value of duty ratio D.
The present embodiment utilizes timer and the PCA module composition 4 adjustable duty ratio PWM output units in tunnel of single-chip microcomputer, and microprocessor is exported by 4 road PWM of program control PWM output unit.
The PCA module of single-chip microcomputer contains 16 special bit timing counters, has 4 16 catch/comparison modules to be attached thereto.The count value of 16 PCA timer conters is exactly the content of register CH and CL.Each module is able to programme to be operated under 4 kinds of patterns: rise/fall along catching, software timer, output or can modulating pulse output at a high speed.When PCA timer conter overflows, if the CMOD register of microprocessor is set to allow interrupt status, just can produces timer counter and interrupt.All PCA modules share an interrupt vector.
The corresponding special function register of each module of PCA. they respectively: the corresponding CCAPM0 of module 0, the corresponding CCAPM1 of module 1, the corresponding CCAPM2 of module 2, the corresponding CCAPM3 of module 3.The mode of operation control bit that special function register has comprised corresponding module.
PCA timer conter is benchmark common time of 4 modules, can exist by programing work: 1/12 frequency of oscillation, 1/2 frequency of oscillation, timer 0 overflow or the input (P3.4) of ECI pin.The counting source of timer is determined by CMOD register.PCA0 and PCA1 are set and are operated in rise/fall along under pattern, detect the crossover point signal of voltage, electric current.
All PCA modules can be done PWM output, enable PWM pattern, the necessary set in the PWMn of module CCAPMn register and EC0Mn position, and its output frequency depends on the clock source of PCA timer.
Because all modules share only PCA timer, so their output frequency is identical.The output duty cycle of modules is independent variation, with use to catch register EPCnL relevant with CCAPnL.When the value of CL register is less than EPCnL and CCAPnL, be output as lowly, when the value of the CL of PCA register is equal to or greater than EPCnL and CCAPnL, be output as height.When the value of CL becomes 00 while overflowing from FF, the content of catching register EPCnH and CCAPnH is loaded in EPCnL and CCAPnL, thereby realize interference-free, upgrades PWM.Because PWM is 8, so:
When EPCnL=0 and CCAPnL=00H, PWM is fixing, and output is high;
When EPCnL=1 and CCAPnL=0FFH, PWM is fixing, and output is low.
Single-chip microcomputer external clock is 11.0592M crystal oscillator, and PCA timer is operated in 1/2 concussion frequency, and the frequency that has above formula can obtain PWM is: fPWM=21.6KHz, arranges PCA0 and PCA1 module and be operated in and can modulate pulsewidth output mode:
PCA0 is connected to the output P3.7 of microprocessor IC1, and the PWM1 output by control unit 40 is connected to driver element, controls the first switching device S1; PCA1 is connected to the output P3.5 of microprocessor IC1, and the PWM2 output by control unit 40 is connected to driver element, controls second switch device S2.
When PCA is operated in rise/fall along triggering trap mode, module is sampled to the saltus step of outside input.When sampling effective saltus step, PCA hardware is just loaded into catching in register CCAPnL and CCAPnH of module by the value of PCA timer conter register CH and CL.
PCA2 and PCA3 are set to rise/fall along catching mode of operation, and combined with hardware circuit design realizes voltage, current detecting in PCA interrupts.
Voltage, current over-zero testing circuit detect output voltage zero crossing by comparator, and analog quantity is converted to digital quantity, send singlechip interruption INT0 and INT1, by the on off state of software program control switch device.
Output sampling unit comprises voltage zero-crossing detection circuit, and voltage zero-crossing detection circuit as shown in Figure 5, in the present embodiment, adopts LM311 voltage comparator to complete voltage zero-cross and detects.Output voltage obtains the AC signal ZC of 50HZ after by step-down transformer, and in the present embodiment, step-down transformer is 220:12V, and transformer output voltage ZC is through being comprised of R17 and C12 the positive input terminal that low pass filter is delivered to voltage comparator U3.-15V obtains the reference voltage of comparator through R18, R20 dividing potential drop, regulate the small phase deviation being produced by RC low pass filter.It is pull-up resistor for exporting RC low pass filter R22 that 3 pin of U3 approximate 0, R21, C30.Its waveform as shown in Figure 6.
Wherein ZC is step-down transformer secondary waveform, and INT is the waveform after voltage comparator.As seen from the figure, at output voltage, when just to negative zero crossing, INT is just in time at trailing edge, and output voltage is when bearing positive zero crossing, and INT is just in time at rising edge.INT output is connected to the INT0 input (single-chip microcomputer P2.0 pin) of delivering to control unit, and single-chip microcomputer utilizes the rise/fall of PCA2 along the phase place of catching judgement output voltage.
Current sampling unit comprises current sampling circuit and current over-zero testing circuit, as shown in Figure 7, in the present embodiment, input sample unit is used precision current transformer as current sample element, the elementary input that is connected on described switch convertor unit of current transformer, input current I1 is elementary through current transformer, the secondary of current transformer can produce one and corresponding output current I2, output current I2 becomes voltage signal by sampling resistor RS, through operational amplifier U2, amplify and obtain sampling voltage VI1, send into zero cross detection circuit ZIC input.Zero cross detection circuit ZIC is identical with voltage zero-crossing detection circuit principle, and its waveform as shown in Figure 8.As seen from the figure, when electric current, INT1 is just in time at trailing edge when bearing positive zero crossing, and when electric current is during just to negative zero crossing, INT1 is just in time at rising edge.The output INT1 of current over-zero testing circuit ZIC is connected to the INT1 input (single-chip microcomputer P2.4 pin) of control unit, and single-chip microcomputer utilizes the rise/fall of PCA3 along the phase place of catching judgement electric current.
For the switching device S3 of afterflow and the driving PWM of S4, by timer, interrupted realizing, its timing waveform figure as shown in Figure 9.The time that produces the cycle of PWM is controlled by timer T1, and the size of duty ratio is controlled by T0.According to the initial value M1 that produces the cycle of PWM and the clock of single-chip microcomputer and determine T1 timer, timer was operated in for 1 clock cycle 16 bit timing device mode of operation is next to be had:
M1＝2
16-f
osc*T
By T=1/fpwm=46.296us, fosc=11.0592, M1=FE00H, the initial value of timer T1 is TH1=0FEH, TL1=00H.
According to the size that will export PWM duty ratio, determine the TH0 of timer T0 and the initial value of TL0.If output PWM duty ratio is D, the initial value of timer T0 is that M0 has:
M0＝2
16-f
osc*T*D
Timer T1 overflows and in interruption, makes the I/O mouth of exporting PWM put 1, and starts timer T0.Timer T0 overflows that to interrupt making exporting the I/0 mouth of PWM clear 0, and timeing closing device T0.
The I/O mouth P1.0 of microprocessor IC1 is connected to driver element as the output of PWM3, controls the 3rd switching device S3; The I/O mouth P3.4 of microprocessor IC1 is connected to driver element as the output of PWM4, controls the 4th switching device S4.
The present embodiment adopts the integrated IGBT gate drivers of IR2110 to form drive circuit, and IR2110 is a kind of binary channels high pressure, High-speed Electric die mould device for power switching, has the high-pressure side suspension drive circuit of bootstrapping floating power supply.Electrical schematic diagram shown in Figure 10 has been shown the drive circuit of the 3rd switching device S3 in driver element, and driver element comprises No. 4 drive circuits, and other No. 3 drive circuits are identical.In the present embodiment, utilize optic coupling element and high-pressure side suspension drive circuit to realize two-stage isolation, high speed photo coupling U5, Micro Controller Unit (MCU) driving signal PWM3 and drive circuit U4 isolation, fully guarantees the reliability of microprocessor program control system.C50 is that bootstrap capacitor, D26 are bootstrap diode, and C101 is filter capacitor.At S3 blocking interval C50, be charged to enough voltage (VCC), when HIN, LIN are high level, voltage VC50 on C50 connects by the VB of U4 and the internal circuit between HO output, and C50 holds by VB and the HO of U4, and the grid of R28 and S3 and source electrode form loop electric discharge.Now C50 is just equivalent between grid and source electrode that a voltage source is added to IGBT1, thereby makes S3 conducting.When HIN, LIN are low level, between VB and HO output, connect and turn-off, conducting between HO and VS output, S3 turn-offs, and LO output low level is turn-offed Q3, Q4 conducting.VCC is through bootstrap diode at the same time, and C50 and Q4 form loop, C50 is charged, and be rapidly C50 makeup energy, so circulation is repeatedly.
The invention provides the AC/AC supply convertor switching device change of current control method that a kind of use microprocessor program for the adjustable power measurement power source special of above-mentioned interchange is controlled, its main program flow chart as shown in figure 11, comprises following steps:
S100) call AD conversion routine and output voltage is carried out to the step of digital-to-analogue conversion sampling input;
S200) step that the reference voltage that calls AD conversion routine output voltage regulating element is provided carries out digital-to-analogue conversion;
S300), according to reference voltage and output voltage, use Digital PID Algorithm to determine the step of duty ratio;
S400) according to duty ratio, set the step of the timing value of PWM output unit;
S500) detect the step of voltage and current zero passage flag bit;
S600) judgement voltage and current zero passage flag bit, calls the step that switching device state is controlled subprogram, and this step comprises following action:
If electric current decline zero passage flag bit be 1 and voltage rising zero passage flag bit be 1, call switching device state and control subprogram S620, return to step S100 cyclical execution of programs;
If Current rise zero passage flag bit be 1 and voltage rising zero passage flag bit be 1, call switching device state and control subprogram S640, return to step S100 cyclical execution of programs;
If Current rise zero passage flag bit be 1 and voltage drop zero passage flag bit be 1, call switching device state and control subprogram S660, return to step S100 cyclical execution of programs;
If electric current decline zero passage flag bit be 1 and voltage drop zero passage flag bit be 1, call switching device state and control subprogram S680, return to step S100 cyclical execution of programs.
In the present embodiment; also comprise and carry out the step S700 of overvoltage judgement and the step S720 of overvoltage protection action; output voltage is converted into 0-5V direct voltage by voltage sensor 0-250V alternating voltage; direct voltage after conversion by AD, change and single-chip microcomputer in the overvoltage protection reference value set compare; if output voltage surpasses default overvoltage protection reference value; control switch device turn-offs Sl, and S2 cuts off the electricity supply.
The AC/AC supply convertor switching device change of current control method that use microprocessor program of the present invention is controlled through improved switching device state, control subprogram as shown in figure 12, comprise the following steps:
S620) PCA0 module is set, makes the first output PWM1 of PWM output unit keep low level; PCA1 module is set, makes the second output PWM2 of PWM output unit keep high level; Make the 3rd output PWM3 of PWM output unit keep high level; Call Interruption and produce adjustable PWM, make the 4th output PWM4 of PWM output unit according to the definite duty ratio output PWM chopping signal of step S300; Return to main program;
S640) PCA0 module is set, makes the first output PWM1 of PWM output unit according to the definite duty ratio output PWM chopping signal of step S300; PCA1 module is set, makes the second output PWM2 of PWM output unit keep high level: make the 3rd output PWM3 of PWM output unit keep high level; Make the 4th output PWM4 of PWM output unit keep low level; Return to main program;
S660) PCA0 module is set, makes the first output PWM1 of PWM output unit keep high level; PCA1 module is set, makes the second output PWM2 of PWM output unit keep low level; Call Interruption and produce adjustable PWM, make the 3rd output PWM3 of PWM output unit according to the definite duty ratio output PWM chopping signal of step S300; Make the 4th output PWM4 of PWM output unit keep low level; Return to main program;
S680) PCA0 module is set, makes the first output PWM1 of PWM output unit keep high level; PCA1 module is set, makes the second output PWM2 of PWM output unit according to the definite duty ratio output PWM chopping signal of step S300; Make the 3rd output PWM3 of PWM output unit keep high level; Make the 4th output PWM4 of PWM output unit keep low level; Return to main program.
In resistance inductive load, the gate-drive state of four switching tubes is divided into 4 intervals in one-period, and switching device state is controlled subprogram and by P3.7, exported the driving signal of S1; The driving signal of P3.5 output S2; The driving signal of P1.0 output S3; The driving signal of P3.4 output S4.When load is pure when resistive, output voltage, electric current same-phase, in one-period, the driving signal of switching tube only has b, two intervals of d, and S3, S4 are as continued flow switch.When load is resistance inductive load, subprogram provides the driving signal of switching device in conjunction with 4 intervals.
The AD conversion routine of the AC/AC supply convertor switching device change of current control method that use microprocessor program of the present invention is controlled comprises the step of AD conversion sampling input data being carried out to Digital smooth filtering, and its flow chart as shown in figure 13.
Step S120 weaves into the input port into AD P1.2 or P1.3, is used for respectively changing output voltage sampled value or output voltage fiducial value.Because microcomputer system often can exist normality, disturb, in order to improve the antijamming capability of system, except hardware measure, can also adopt digital filtering to be slackened or filtering.In the AD conversion routine shown in Figure 13, the step S160 that comprises smothing filtering, averages the value of this AD conversion and conversion value addition last time, realizes Digital smooth filtering function.
The AC/AC supply convertor switching device change of current control method that use microprocessor program of the present invention is controlled adopts zero passage detection rise/fall, and along catching, interrupt routine is realized voltage zero-cross detection and current over-zero detects, and microprocessor utilizes rise/fall along the phase place of capture interrupt judgement voltage and current.Zero passage detection rise/fall along the flow chart that catches interrupt routine as shown in figure 14, comprises the step S520 of judgement interrupt source PCA2 and PCA3; Judge that rise/fall is along the step S540 of trap state, and along trap state, the step S560 of zero crossing flag bit and the step S580 of modification rising edge/trailing edge trap mode are set according to interrupt source and rise/fall.
The system of controlling as microprocessor, method of the present invention also comprises system initialization routine, and system initialization content comprises:
1) PCA initialization:
PCA0, PCA1 module is arranged to modulate pulsewidth output mode; PCA2, PCA3 module is arranged to rising edge and is caught mode of operation.Configuration CMOD register PCA counter is always 1/2fosc, allows PCA to interrupt.Preparation CCON special function register is forbidden PCA0, and PCA1 interrupts, and allows PCA2, and PCA3 module is interrupted, and forbids that PCA timer overflows interruption, and the zero clearing of PCA interrupt flag bit starts PCA timer.
2) timer T1 initialization:
Timer is operated under 16 IT timing working patterns, 46.096us regularly, i.e. and the initial value THI=0FEH of timer T1, TL1=00H. timer T1 overflows and allows to interrupt, and interrupt flag bit zero clearing, starts timer T1.
3) timer T0 initialization:
Timer is operated under 16 IT timing working patterns, determines the initial value of timer T0, and timer T0 overflows and allows to interrupt, interrupt flag bit zero clearing, timeing closing device T0.
4) interrupt priority level is set, PCA interrupt priority level is higher than T0, the interrupt priority level of T1.
5) overvoltage protection reference value is set.
6) electric current and voltage zero crossing flag bit zero clearing.
Those of ordinary skill in the art will be appreciated that; above embodiment is only for technical scheme of the present invention is described; and be not used as limitation of the invention; any variation of the above embodiment being done based on connotation of the present invention, modification, all will drop in the protection range of claim of the present invention.
Claims (10)
1. for exchanging an AC/AC supply convertor switching device change of current control method for adjustable power measurement power source special, comprise following steps:
S100) call AD conversion routine and output voltage is carried out to the step of digital-to-analogue conversion sampling input;
S200) step that the reference voltage that calls AD conversion routine output voltage regulating element is provided carries out digital-to-analogue conversion;
S300), according to reference voltage and output voltage, use Digital PID Algorithm to determine the step of duty ratio;
S400) according to duty ratio, set the step of the timing value of PWM output unit;
S500) detect the step of voltage and current zero passage flag bit, utilize rise/fall along capture interrupt program, the phase place of judgement voltage and current; Described rise/fall comprises following action along catching interrupt routine:
S520) judgement rise/fall is along the step that catches interrupt source;
S540) judgement rise/fall is along the step of trap state;
S560) according to interrupt source and rise/fall along trap state, the step of voltage and current zero passage flag bit is set;
S580) revise the step of rising edge/trailing edge trap mode;
Wherein, described voltage and current zero passage flag bit comprises voltage drop zero passage flag bit, voltage rising zero passage flag bit, electric current decline zero passage flag bit and Current rise zero passage flag bit;
S600) judgement voltage and current zero passage flag bit, calls the step that switching device state is controlled subprogram, and this step comprises following action:
If electric current decline zero passage flag bit be 1 and voltage rising zero passage flag bit be 1, call switching device state and control subprogram S620, return to step S100 cyclical execution of programs;
If Current rise zero passage flag bit be 1 and voltage rising zero passage flag bit be 1, call switching device state and control subprogram S640, return to step S100 cyclical execution of programs;
If Current rise zero passage flag bit be 1 and voltage drop zero passage flag bit be 1, call switching device state and control subprogram S660, return to step S100 cyclical execution of programs;
If electric current decline zero passage flag bit be 1 and voltage drop zero passage flag bit be 1, call switching device state and control subprogram S680, return to step S100 cyclical execution of programs;
Described switching device state is controlled subprogram and is comprised following steps:
S620) make the first output of PWM output unit keep low level; Make the second output of PWM output unit keep high level; Make the 3rd output of PWM output unit keep high level; Make the 4th output of PWM output unit according to the definite duty ratio output PWM chopping signal of step S300; Return to main program;
S640) make the first output of PWM output unit according to the definite duty ratio output PWM chopping signal of step S300; Make the second output of PWM output unit keep high level: to make the 3rd output of PWM output unit keep high level; Make the 4th output of PWM output unit keep low level; Return to main program;
S660) make the first output of PWM output unit keep high level; Make the second output of PWM output unit keep low level; Make the 3rd output of PWM output unit according to the definite duty ratio output PWM chopping signal of step S300; Make the 4th output of PWM output unit keep low level; Return to main program;
S680) make the first output of PWM output unit keep high level; Make the second output of PWM output unit according to the definite duty ratio output PWM chopping signal of step S300; Make the 3rd output of PWM output unit keep high level; Make the 4th output of PWM output unit keep low level; Return to main program.
2. AC/AC supply convertor switching device change of current control method according to claim 1, is characterized in that described AD conversion routine comprises the step of AD conversion sampling input data being carried out to Digital smooth filtering.
3. AC/AC supply convertor switching device change of current control method according to claim 1; it is characterized in that comprising the step of carrying out overvoltage judgement and overvoltage protection action; if output voltage surpasses default overvoltage protection reference value, control switch device is cut off the electricity supply.
4. a right to use requires the adjustable power measurement power source special of interchange of the AC/AC supply convertor switching device change of current control method described in 1,2 or 3, comprise switch convertor unit, input sample unit, output sampling unit, control unit and driver element, described switch convertor unit is connected between AC power and AC load, it is characterized in that: described switch convertor unit adopts 4 to have switching device and 4 diodes of controlling the utmost point, forms the class Buck-Boost circuit that comprises mirror image brachium pontis; The switching device of described class Buck-Boost circuit shares one group of filter inductance and filter capacitor;
The anode of 4 diodes and negative electrode be negative electrode and the anode of 4 switching devices of reverse parallel connection to first to fourth respectively; The anode of the first switching device and second switch device forms the input of switch convertor unit, is connected respectively to the two ends of input ac power; The negative electrode of the 3rd switching device and the 4th switching device is connected respectively to the two ends of filter capacitor, forms the output of switch convertor unit, is connected respectively to the two ends of output AC load; The negative electrode of the first switching device is connected to one end of anode and the filter inductance element of the 3rd switching device, and the negative electrode of second switch device is connected to the anode of the 4th switching device and the other end of filter inductance element;
Described switch convertor unit is connected to and described control unit by described input sample unit and output sampling unit; Described control unit is connected to the control utmost point of described 4 switching devices by described driver element.
5. the adjustable power measurement power source special of interchange according to claim 4, it is characterized in that described control unit is microprocessor program control unit, comprise memory, IO interface circuit, AD converter and the PWM output unit of microprocessor, storage data and the control program of executive control program; The input of described control unit comprises digital signal input end and input end of analog signal, described digital signal input end is connected to microprocessor by IO interface circuit, described input end of analog signal is connected to microprocessor by AD converter, wherein has at least an input end of analog signal to be connected with output voltage regulating element; Described PWM output unit at least comprises 4 road PWM modules, and microprocessor connects described driver element by PWM module.
6. the adjustable power measurement power source special of interchange according to claim 5, is characterized in that described output sampling unit comprises voltage sampling circuit and voltage zero-crossing detection circuit; The input of voltage sampling circuit is connected to the output of described switch convertor unit, and the output of voltage sampling circuit is connected to the input end of analog signal of described control unit; The output of switch convertor unit is connected to the digital signal input end of described control unit by voltage zero-crossing detection circuit.
7. the adjustable power measurement power source special of interchange according to claim 5, is characterized in that described input sample unit comprises current sampling circuit and current over-zero testing circuit; Current sampling circuit is connected to the input of described switch convertor unit, and the output of current sampling circuit is connected to the digital signal input end of described control unit by current over-zero testing circuit.
8. the adjustable power measurement power source special of interchange according to claim 6, the output that it is characterized in that described voltage zero-crossing detection circuit is connected to the external signal of described microprocessor and catches input INT0, and microprocessor utilizes rise/fall along the phase place of catching judgement voltage.
9. the adjustable power measurement power source special of interchange according to claim 7, the output that it is characterized in that described current over-zero testing circuit is connected to the external signal of described microprocessor and catches input INT1, and microprocessor utilizes rise/fall along the phase place of catching judgement electric current.
10. according to the adjustable power measurement power source special of interchange described in the arbitrary claim of claim 4 to 9, it is characterized in that described driver element comprises high-pressure side suspension drive circuit and optic coupling element, the output of described control unit is connected to the control utmost point of described switching device after isolating by optic coupling element and high-pressure side suspension drive circuit two-stage.
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| CN102821531B (en) * | 2012-08-29 | 2015-03-11 | 孝感市捷能特种光源照明器具有限公司 | 'AC-AC (alternating current) regulation and control' based numerical-control HID (high intensity discharge) driving method and driver applying same |
| CN104539170B (en) * | 2015-01-09 | 2017-02-22 | 河北工业大学 | Three-level Cuk voltage regulation constant current source and operation method thereof |
| CN105471263B (en) * | 2015-12-23 | 2018-05-29 | 成都芯源系统有限公司 | Buck-boost converter and controller and control method thereof |
| CN109586314B (en) * | 2018-11-23 | 2022-02-18 | 南京理工大学 | Three-phase reactive power compensation device without direct current energy storage unit |
| CN110768539A (en) * | 2019-01-22 | 2020-02-07 | 邢台子中电子科技有限公司 | AC-AC converter using IGBT or MOS tube and control method thereof |
| CN111488024B (en) * | 2019-01-25 | 2022-04-19 | 添可智能科技有限公司 | Cleaning equipment and power adjusting method |
| CN110112768A (en) * | 2019-04-04 | 2019-08-09 | 华南理工大学 | A kind of system and method for multiple fluctuating power power supplys used in parallel |
| CN114079417A (en) * | 2020-08-18 | 2022-02-22 | 厦门市必易微电子技术有限公司 | Alternating-current chopper circuit and single-phase alternating-current motor driving system |
| US11437947B2 (en) | 2020-08-18 | 2022-09-06 | Xiamen Kiwi Instruments Corporation | AC chopping circuit and associated single-phase AC motor driving system |
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| CN202150804U (en) * | 2011-09-20 | 2012-02-22 | 辽宁省电力有限公司 | AC adjustable special-purpose power supply for electric power measuring |
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