CN102830266B - Phase discriminating circuit of residual current phase - Google Patents
Phase discriminating circuit of residual current phase Download PDFInfo
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- CN102830266B CN102830266B CN201210324883.2A CN201210324883A CN102830266B CN 102830266 B CN102830266 B CN 102830266B CN 201210324883 A CN201210324883 A CN 201210324883A CN 102830266 B CN102830266 B CN 102830266B
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Abstract
The invention provides a phase discriminating circuit of a residual current phase. The phase discriminating circuit comprises a reference square wave generating circuit of power supply voltage, a signal square wave generating circuit of residual current and a controller; the reference square wave generating circuit of power supply voltage comprises a first filter wave circuit, an isolated reduction voltage circuit and a first square wave generating circuit; the signal square wave generating circuit of residual current comprises a residual current induction circuit, a signal state conversion circuit, a second filter circuit, a signal primary amplifying circuit, a signal secondary amplifying circuit and a second square wave generating circuit; the controller comprises an A/D (analogue/digital) conversion unit, a timing unit and an interrupt unit; the phase discriminating circuit of the residual current phase applies the amplifying units twice, utilizes a subsequent second channel when a residual current signal is small, and utilizes the combination a first channel and the second channel when a residual electric signal is large, so that the sampling precision is greatly improved; a square wave comparison signal is generated from the second channel; the phase of the residual current can be accurately measured under the situation that the residual electric signal is smaller, and the problem that the residual current phase detection cannot consider the detection accuracy of both large and small residual currents in the prior art is effectively avoided.
Description
Technical field
The present invention relates to a kind of three-phase residual current detection circuit, specifically a kind of phase discriminator of residual current phase place, belongs to residual current detection technical field.
Background technology
Residual current circuit breaker is more and more wider in the application of market, wherein simulate discrete and still occupy mass market, some products can only carry out residual current protecting and there is no residual current display unit, although what have has a residual current display unit, but can only detect total residual current, and can not accurately detect residual current, do not occur in which phase wherein, yet, residual current substantially all occurs in single-phase conventionally, once there is residual current, cause large-area power-cuts maintenance, particularly in rural power grids, circuit is long, with electrodispersion, and be distributed in mountain area more, maintainer need to be to A, B, C three-phase is all investigated, greatly increased maintainer's workload, efficiency is relatively low.
Chinese patent literature CN101162834A discloses sound-deadening electricity-saving vector type electrical leakage testing method and earth leakage protective device, and the vector that detects low-voltage distributing line Leaked Current of Line to Ground by zero sequence current mutual inductor is residual current.The residual current of the prior art is after rectification is amplified, the size that interface microcontroller PC4 obtains leakage current is delivered on one tunnel, interface microcontroller PC0 is delivered to through phase detecting circuit in another road, utilize single-chip microcomputer to measure the poor of two adjacent AC signal and phase reference, thereby it is poor to obtain two adjacent phase of ac signal.Residual current after the method for detecting phases of the residual current of the prior art amplifies rectification only uses an operational amplifier to carry out detected phase, during this Design of Amplifiers, if designed for little electric current, need to arrange larger multiplication factor, could meet the needs that little electric current amplifies, if but the electric current now detecting is large electric current, the multiple of method is excessive; If arranged for large electric current, can not meet the amplification demand of little electric current.That is to say that the arranging of operational amplifier in this circuit is difficult to take into account large electric current and little electric current.Due to and the size of our unpredictable residual current in reality, so the method for detecting phases of this residual current cannot be taken into account the detection accuracy of large and small residual current.
Summary of the invention
Technical problem to be solved by this invention is in prior art, to the phase-detection of residual current, to take into account the detection accuracy of large and small residual current, thereby provides a kind of large and small leakage current can both carry out the circuit of phase-detection.
For solving the problems of the technologies described above, the present invention is achieved by the following technical solutions:
A phase discriminator for residual current phase place, comprises the reference square wave generative circuit of power supply voltage, signal square wave generative circuit and the controller of residual current, wherein
The reference square wave generative circuit of described power supply voltage, comprises
The first filter circuit: its input termination alternating current, carries out exporting after filtering to described alternating current;
Isolated buck circuit: be connected with the output of described the first filter circuit, described filtered supply voltage is carried out to step-down processing;
The first square wave generative circuit: be connected with the output of described isolated buck circuit, convert the supply voltage after described step-down to square-wave signal by sine wave signal, described square-wave signal is the reference square wave of power supply voltage;
The signal square wave generative circuit of described residual current, comprises residual current sensor circuit, signal condition change-over circuit, the second filter circuit, the elementary amplifying circuit of signal, signal secondary amplification circuit and the second square wave generative circuit, wherein:
Residual current sensor circuit: its input is connected on circuit to be measured, for the residual current of induction line;
Signal condition change-over circuit: the output of residual current sensor circuit described in its input termination, after being converted to voltage signal, exports residual current signal;
The second filter circuit: the output of signal condition change-over circuit described in its input termination, carries out described voltage signal to export after filtering;
The elementary amplifying circuit of signal: the voltage signal after the conversion of residual current signal is raised to the reference voltage place at 0.5 times, make this voltage signal have complete sinusoidal waveform, the elementary amplifying circuit of described signal comprises two inputs and an output, the first input end of the elementary amplifying circuit of described signal connects the output of described the second filter circuit, and second of the elementary amplifying circuit of described signal is inputted the reference voltage of 0.5 times of termination;
Signal secondary amplification circuit: the voltage signal after the elementary amplifying circuit of described signal is amplified amplifies again, described signal secondary amplification circuit comprises two inputs and two outputs, the first input end of described signal secondary amplification circuit connects the output of the elementary amplifying circuit of described signal, and second of described signal secondary amplification circuit is inputted the reference voltage of 0.5 times of termination;
The second square wave generative circuit: convert the voltage after amplifying to square-wave signal by sine wave signal, described the second square wave generative circuit comprises two inputs and an output, the first input end of described the second square wave generative circuit connects the first output of described signal secondary amplification circuit, second of described the second square wave generative circuit is inputted the reference voltage of 0.5 times of termination, the signal square wave that the output signal of described output is described residual current;
Described controller, comprises
AD converting unit: for detection of the size of residual current, comprise an AD conversion mouth and the 2nd AD conversion mouthful, a described AD conversion mouth connects the output of the elementary amplifying circuit of described signal, and described the 2nd AD conversion mouth connects the second output of described signal secondary amplification circuit;
Interrupt location, comprise for receive power supply voltage reference square wave the first fracture and for receiving signal square wave second fracture of residual current, in described first, fracture connects the output of described the first square wave generative circuit, and fracture connects the output of described the second square wave generative circuit in described second;
Timing unit, record fracture in the reference square wave and described second that fracture in described first receives described power supply voltage and receive the rising edge of signal square wave or the time difference of trailing edge of described residual current, the phase difference that residual current lags behind benchmark phase obtains by formula φ=2 π tl/Tl, Tl is power frequency period, by the square wave after reference signal shaping, start timing, square wave after residual current signal shaping stops timing, between institute's timing, is tl.
The phase discriminator of described residual current phase place, the signal square wave generative circuit of described residual current also comprises protective circuit, signal condition change-over circuit described in the input termination of described protective circuit, the second filter circuit described in the output termination of described protective circuit.
The phase discriminator of described residual current phase place, described the first filter circuit comprises piezo-resistance U1, common mode inductance T1, capacitor C 1, alternating current connects the two ends of described piezo-resistance U1, two inputs of common mode inductance T1 described in two terminations of described piezo-resistance U1, connect the input of described isolated buck circuit jointly after two outputs of described common mode inductance T1 are connected with the two ends of described capacitor C 1.
The phase discriminator of described residual current phase place, described isolated buck circuit comprises two winding transformer S1.
The phase discriminator of described residual current phase place, described the first square wave generative circuit comprises resistance R 1, R2, R3, R4, capacitor C 2, diode D1, triode Q1, the output of described isolated buck circuit is connected with the base stage of described triode Q1 by resistance R 1, described capacitor C 2, diode D1, after resistance R 2 is in parallel, an end is connected on the link of described resistance R 1 and described triode Q1 base stage, ground connection after the other end is connected with the emitter of described triode Q1, the collector electrode of described triode Q1 connects one end of described resistance R 3, another termination DC power supply of described resistance R 3, one end of described resistance R 4 is connected on the collector electrode of described triode Q1 and the link of described resistance R 3, the other end of described resistance R 4 and described controller first in fracture be connected.
The phase discriminator of described residual current phase place, described residual current sensor circuit comprises zero sequence current mutual inductor.
The phase discriminator of described residual current phase place, described signal condition change-over circuit comprises resistance R 5.
The phase discriminator of described residual current phase place, described the second filter circuit comprises capacitor C 3, the two ends of described capacitor C 3 connect the first input end of the output of described signal condition change-over circuit, the elementary amplifying circuit of described signal simultaneously.
The phase discriminator of described residual current phase place, the elementary amplifying circuit of described signal comprises resistance R 6, R7, R8, R9, capacitor C 4, operational amplifier U1C, the first output of one termination the second filter circuit of described resistance R 6, the reverse input end of operational amplifier U1C described in another termination, second output that connects the second filter circuit of described resistance R 7 one end, the input in the same way of operational amplifier U1C described in another termination, between the output of described operational amplifier U1C and reverse input end, be connected described resistance R 8, described output connects described signal secondary amplification circuit first input end simultaneously, the one AD conversion mouthful, the link of the input in the same way of resistance R 7 and described operational amplifier U1C described in one termination of described capacitor C 4, the other end ground connection of described capacitor C 4, the link of the input in the same way of resistance R 7 and described operational amplifier U1C described in one termination of described resistance R 9, the reference voltage that another termination is 0.5 times.
The phase discriminator of described residual current phase place, described signal secondary amplification circuit comprises resistance R 10, R11, R12, R13, capacitor C 5, C6, operational amplifier U1D, the reverse input end of described operational amplifier U1D is connected with the output of the elementary amplifying circuit of described signal by described resistance R 10, the input in the same way of described operational amplifier U1D connects the reference voltage of 0.5 times by described resistance R 11, between the input in the same way of described operational amplifier U1D and reverse input end, be connected capacitor C 5, between the output of described operational amplifier U1D and reverse input end, by described resistance R 12, be connected, the output of described operational amplifier U1D is connected with the first input end of described the second square wave generative circuit, the output of described operational amplifier U1D ground connection again after being connected with described capacitor C 6 by described resistance R 13, described resistance R 13 is changed mouth with termination the 2nd AD that is connected of described capacitor C 6.
The phase discriminator of described residual current phase place, described the second square wave generative circuit comprises resistance R 14, R15, operational amplifier U1B; The input in the same way of described operational amplifier U1B is connected with the first output of described signal secondary amplification circuit by described resistance R 14, the reverse input end of described operational amplifier U1B connects the reference voltage of 0.5 times, and the output of described operational amplifier U1B connects fracture in described second by described resistance R 15.
The phase discriminator of described residual current phase place, described controller is single-chip microcomputer.
The phase discriminator of described residual current phase place; described protective circuit comprises diode D2, D3; ground connection after the negative pole of described diode D2 is connected with the positive pole of described diode D3; the positive pole of described diode D2 connects the negative pole of described diode D3, and jointly connects the output of described signal condition change-over circuit.
The phase discriminator of described residual current phase place, the operating voltage that described reference voltage is controller.
The phase discriminator of described residual current phase place, the operating voltage of single-chip microcomputer is 5V.
The phase discriminator of described residual current phase place, the operating voltage of single-chip microcomputer is 3.3V.
Technique scheme of the present invention has the following advantages compared to existing technology:
(1) phase discriminator of residual current phase place of the present invention, the reference square wave generative circuit that comprises power supply voltage, signal square wave generative circuit and the controller of residual current, the reference square wave generative circuit of this power supply voltage, comprise the first filter circuit, isolated buck circuit and the first square wave generative circuit, the signal square wave generative circuit of this residual current comprises residual current sensor circuit, signal condition change-over circuit, the second filter circuit, the elementary amplifying circuit of signal, signal secondary amplification circuit and the second square wave generative circuit, this controller comprises AD converting unit, timing unit, interrupt location.The phase discriminator of above-mentioned residual current phase place has been applied amplifying circuit twice, in the time of can making little residual electricity signal, use the second channel of back, during large residual electricity signal, use first passage to add the mode of second channel, greatly improved the precision of sampling, from high channel, produce square wave comparison signal, make it in the situation that residual electricity signal is less, also can accurately measure the phase place that residual current occurs, effectively avoided to the phase-detection of residual current, cannot taking into account in prior art the problem of the detection accuracy of large and small residual current.
(2) phase discriminator of residual current phase place of the present invention; the signal square wave generative circuit of this residual current also comprises protective circuit; make the voltage of signal condition change-over circuit output in the scope limiting, in order to avoid damage operational amplifier, guarantee the normal work of circuit.
(3) phase discriminator of residual current phase place of the present invention, a 0.5VREF(Voltage Reference is set, reference voltage) reference power supply is raised residual electricity signal, makes it have complete sinusoidal waveform, has improved real-time and the accuracy of residual current detection.
(4) phase discriminator of residual current phase place of the present invention, utilizes triode and operational amplifier to realize, and only has a road power supply, avoids using two-way power supply, and circuit is simplified.
Accompanying drawing explanation
For content of the present invention is more likely to be clearly understood, below in conjunction with accompanying drawing, the present invention is further detailed explanation, wherein,
Fig. 1 is an example structure schematic diagram of the phase discriminator of residual current phase place of the present invention;
Fig. 2 is the circuit theory diagrams of the reference square wave generative circuit of the power supply voltage of the phase discriminator of residual current phase place described in Fig. 1;
Fig. 3 is the circuit theory diagrams of the signal square wave generative circuit of the residual current of the phase discriminator of residual current phase place described in Fig. 1;
Fig. 4 is another example structure schematic diagram of the phase discriminator of residual current phase place of the present invention;
Fig. 5 is the circuit theory diagrams of the signal square wave generative circuit of the residual current of the phase discriminator of residual current phase place described in Fig. 4;
Fig. 6 is phase measurement each point waveform schematic diagram.
In figure, Reference numeral is expressed as: the reference square wave generative circuit of 1-power supply voltage, 11-the first filter circuit, 12-isolated buck circuit, 13-the first square wave generative circuit, the signal square wave generative circuit of 2-residual current, 21-residual current sensor circuit, 22-signal condition change-over circuit, 23-the second filter circuit, the elementary amplifying circuit of 24-signal, 25-signal secondary amplification circuit, 26-the second square wave generative circuit, 27-protective circuit, 3-controller, 31-AD converting unit, 311-the one AD conversion mouthful, 312-the 2nd AD conversion mouthful, 32-timing unit, 33-interrupt location, fracture in 331-first, fracture in 332-second.
Embodiment
embodiment 1:
As shown in Figure 1, it comprises the reference square wave generative circuit 1 of power supply voltage, signal square wave generative circuit 2 and the controller 3 of residual current to the structure of the phase discriminator of residual current phase place of the present invention.
The reference square wave generative circuit 1 of described power supply voltage comprises the first filter circuit 11, isolated buck circuit 12 and the first square wave generative circuit 13, and described the first filter circuit 11 input termination 220V alternating currents, carry out exporting after filtering to described alternating current; Shown in Figure 2, in the present embodiment, described the first filter circuit 11 comprises piezo-resistance U1, common mode inductance T1, capacitor C 1,220V alternating current connects the two ends of described piezo-resistance U1, and two inputs of common mode inductance T1 described in two terminations of described piezo-resistance U1 connect the input of described isolated buck circuit jointly after two outputs of described common mode inductance T1 are connected with the two ends of described capacitor C 1.Described isolated buck circuit 12 is connected with the output of described the first filter circuit, to described filtered supply voltage isolate, step-down processes; Shown in Figure 2, in the present embodiment, described isolated buck circuit 12 comprises can further reduce the two winding transformer S1 that EMC disturbs, the elementary two ends that are connected on described capacitor C 1 of described two winding transformer S1, S1 level of described two winding transformer is as the input of the first square wave generative circuit 13 described in the output termination of described isolated buck circuit 12.Described the first square wave generative circuit 13 is connected with the output of described isolated buck circuit 12, converts the supply voltage after described step-down to square-wave signal by sine wave signal, and described square-wave signal is the reference square wave of power supply voltage.Shown in Figure 2, in the present embodiment, described the first square wave generative circuit 13 comprises resistance R 1, R2, R3, R4, capacitor C 2, diode D1, triode Q1, one end ground connection in a winding of S1 level of described two winding transformer, the other end is connected with the base stage of described triode Q1 by resistance R 1, described capacitor C 2, diode D1, after resistance R 2 is in parallel, an end is connected on the link of described resistance R 1 and described triode Q1 base stage, ground connection after the other end is connected with the emitter of described triode Q1, the collector electrode of described triode Q1 connects one end of described resistance R 3, another termination+5V DC power supply of described resistance R 3, one end of described resistance R 4 is connected on the collector electrode of described triode Q1 and the link of described resistance R 3, the other end of described resistance R 4 and described controller 3 first in fracture 331 be that IRQ1 in Fig. 2 is connected, export a square-wave signal.
The signal square wave generative circuit 2 of described residual current comprises residual current sensor circuit 21, signal condition change-over circuit 22, the second filter circuit 23, the elementary amplifying circuit 24 of signal, signal secondary amplification circuit 25 and the second square wave generative circuit 26.
Described residual current sensor circuit 21 inputs are connected on circuit to be measured, for the residual current of induction line; Shown in Figure 3, in the present embodiment, described residual current sensor circuit 21 comprises zero sequence current mutual inductor TA, in its input termination phase three-wire three circuit, and one end ground connection of secondary side.
As other execution modes, in the input termination three-phase and four-line circuit of described zero sequence current mutual inductor TA.
Described in described signal condition change-over circuit 22 input terminations, the output of residual current sensor circuit 21, exports after the residual current signal that described zero sequence current mutual inductor TA is exported is converted to voltage signal; Shown in Figure 3, in the present embodiment, described signal condition change-over circuit 22 comprises resistance R 5, and two ends of described resistance R 5 are connected on the secondary side of described zero sequence current mutual inductor TA.
Described in described the second filter circuit 23 input terminations, the output of signal condition change-over circuit 22, carries out described voltage signal to export after filtering; Shown in Figure 3, in the present embodiment, described the second filter circuit 23 comprises capacitor C 3, and the two ends of described capacitor C 3 connect the two ends of described resistance R 5 simultaneously.
The elementary amplifying circuit 24 of described signal raises the voltage signal after the conversion of residual current signal at 0.5VREF place, makes this voltage signal have complete sinusoidal waveform, the elementary amplifying circuit 24 of described signal comprises two inputs and an output, and the first input end of the elementary amplifying circuit 24 of described signal connects the output of described the second filter circuit 23, the second input termination 0.5VREF of the elementary amplifying circuit 24 of described signal, shown in Figure 3, in the present embodiment, the elementary amplifying circuit 24 of described signal comprises resistance R 6, R7, R8, R9, capacitor C 4, operational amplifier U1C, one end of capacitor C 3 described in one termination of described resistance R 6, the reverse input end of operational amplifier U1C described in another termination, the other end that connects described capacitor C 3 of described resistance R 7 one end, the input in the same way of operational amplifier U1C described in described resistance R 7 another terminations, between the output of described operational amplifier U1C and reverse input end, be connected described resistance R 8, described output connects described signal secondary amplification circuit 25 first input ends simultaneously, the one AD conversion mouth 311 of the AD converting unit 31 of controller 3, the link of the input in the same way of resistance R 7 and described operational amplifier U1C described in one termination of described capacitor C 4, the other end ground connection of described capacitor C 4, the link of the input in the same way of resistance R 7 and described operational amplifier U1C described in one termination of described resistance R 9, another termination 0.5VREF.
Voltage signal after the elementary amplifying circuit 24 of 25 pairs of described signals of described signal secondary amplification circuit amplifies amplifies again, described signal secondary amplification circuit 25 comprises two inputs and two outputs, the first input end of described signal secondary amplification circuit 25 connects the output of the elementary amplifying circuit 24 of described signal, the second input termination 0.5VREF of described signal secondary amplification circuit 25, shown in Figure 3, in the present embodiment, described signal secondary amplification circuit 25 comprises resistance R 10, R11, R12, R13, capacitor C 5, C6, operational amplifier U1D, the reverse input end of described operational amplifier U1D is connected with the output of described operational amplifier U1C by described resistance R 10, the input in the same way of described operational amplifier U1D meets 0.5VREF by described resistance R 11, between the input in the same way of described operational amplifier U1D and reverse input end, be connected capacitor C 5, between the output of described operational amplifier U1D and reverse input end, by described resistance R 12, be connected, the output of described operational amplifier U1D is connected with the first input end of described the second square wave generative circuit 26, the output of described operational amplifier U1D ground connection again after being connected with described capacitor C 6 by described resistance R 13, described resistance R 13 is changed mouth 312 with the 2nd AD of the AD converting unit 31 that is connected termination controller 3 of described capacitor C 6.
Described the second square wave generative circuit 26 converts the voltage after amplifying to square-wave signal by sine wave signal, described the second square wave generative circuit 26 comprises two inputs and an output, the first input end of described the second square wave generative circuit 26 connects the first output of described signal secondary amplification circuit 25, the second input termination 0.5VREF of described the second square wave generative circuit 26, the signal square wave that the output signal of described output is described residual current; Shown in Figure 3, in the present embodiment, described the second square wave generative circuit 26 comprises resistance R 14, R15, operational amplifier U1B; The input in the same way of described operational amplifier U1B is connected with described operational amplifier U1D output by described resistance R 14, the reverse input end of described operational amplifier U1B meets 0.5VREF, the output of described operational amplifier U1B by described resistance R 15, connect described controller 3 interrupt location 33 second in fracture 332, i.e. IRQ2 in Fig. 3.
Controller 3, comprise AD converting unit 31, timing unit 32, interrupt location 33, described AD converting unit 31 is for detection of the size of residual current, comprise an AD conversion mouthful the 311 and the 2nd AD conversion mouth 312, described interrupt location 33 comprise for receive power supply voltage reference square wave the first fracture 331 and for receiving signal square wave second fracture 332 of residual current, described timing unit records the rising edge of signal square wave or the time difference of trailing edge that fracture 332 in the reference square wave and described second that fracture 331 in described first receives described power supply voltage receives described residual current, the phase difference that residual current lags behind benchmark phase obtains by formula φ=2 π tl/Tl, Tl is power frequency period, by the square wave after reference signal shaping, start timing, square wave after residual current signal shaping stops timing, between institute's timing, be tl.In the present embodiment, the single-chip microcomputer that described controller 3 is 5V for operating voltage, the operating voltage that described reference voltage is controller, so 0.5VREF is 2.5V.
AD1 place is connected with an AD conversion mouthful the 311, a 2nd AD conversion mouth 312 for AD converting unit 31 respectively with AD2 place, can residual current signal be gathered and be calculated.AD1 place samples to first passage residual current, AD2 place samples to second channel residual current, when single-chip microcomputer detects AD2 in undersaturated condition or saturation condition, be that voltage signal after residual current conversion is between 0-2.5V time, utilize AD1 place to sample to first passage residual current, when single-chip microcomputer detects the state of AD2 after saturated, be that voltage signal after residual current conversion is while being greater than 2.5V, utilize AD1 place to sample to first passage residual current, meanwhile, utilize AD2 place to sample to second channel residual current.
The residual current of AD2 when undersaturated condition or saturation condition is little residual current, and the residual current of AD2 in saturated rear state is large residual current.In the present embodiment, during little residual current signal, when the voltage signal after residual current conversion is between 0-2.5V, use AD2 place to sample to second channel leakage current; During large residual current signal, i.e., when the voltage signal after residual current conversion is greater than 2.5V, use AD1 place to the sampling of first passage residual current, AD2 place, second channel residual current to be sampled simultaneously, the residual current of the two is added and is large residual current; Then fracture 332 is processed in second of the interrupt location 33 by single-chip microcomputer, can accurately judge that residual current is to occur in which phase place, facilitates staff to overhaul.
As other execution modes, controller is that operating voltage is the single-chip microcomputer of 3.3V, the operating voltage that described reference voltage is controller, and 0.5VREF is 1.8V or 2V.
The phase discriminator of residual current phase place of the present invention, two winding transformer S1 secondary side produces a reference square wave, the residual current square wave detecting with described zero sequence current mutual inductor TA forms relatively, by single-chip microcomputer, process and calculate, calculate accurately residual current and occur in which phase place, facilitate staff to overhaul fast.
Using power supply phase (A phase) as benchmark phase, convert power supply, residual current shaping to corresponding with it sine wave signal, square-wave signal, send into respectively single-chip microcomputer first in fracture 332 in fracture 331 and second, utilize the timing unit 32 of single-chip microcomputer, time difference to the rising edge of two square-wave signals measures, and then pass through calculating, thereby realize the measurement of phase place.The each several part waveform of relevant phase measurement as shown in Figure 6.In Fig. 6, (a) figure is benchmark phase signals waveform, in Fig. 6, (b) figure is square wave corresponding after the shaping of benchmark phase signals, in Fig. 6, (c) figure is residual current signal waveform, and in Fig. 6, (d) figure is square wave corresponding after residual current signal shaping, and Tl is power frequency period 20ms.By the square wave after the shaping of benchmark phase signals, start timing, square wave after residual current signal shaping stops timing, between institute's timing, be tl, as shown in (c) figure, figure (d) in Fig. 6, tl has represented that residual current lags behind the phase difference=2 π tl/Tl of benchmark phase.
embodiment 2:
On the basis of above-described embodiment 1; the signal square wave generative circuit 2 of described residual current also comprises protective circuit 27; shown in Figure 4, signal condition change-over circuit 22 described in the input termination of described protective circuit 27, the second filter circuit 23 described in the output termination of described protective circuit 27.Shown in Figure 5; in the present embodiment; described protective circuit 27 comprises diode D2, D3; make the residual current of zero sequence current mutual inductor TA output after described resistance R 5; the voltage of output is no more than 0.7V, in order to avoid damage described operational amplifier U1C, the negative pole of described diode D2 is connected on the earth terminal of described resistance R 5 after being connected with the positive pole of described diode D3; the positive pole of described diode D2 connects the negative pole of described diode D3, and jointly connects the other end of described resistance R 5.
Obviously, above-described embodiment is only for example is clearly described, and the not restriction to execution mode.For those of ordinary skill in the field, can also make other changes in different forms on the basis of the above description.Here exhaustive without also giving all execution modes.And the apparent variation of being extended out thus or change are still among the protection range in the invention.
Claims (16)
1. a phase discriminator for residual current phase place, is characterized in that, comprises the reference square wave generative circuit of power supply voltage, signal square wave generative circuit and the controller of residual current, wherein
The reference square wave generative circuit of described power supply voltage, comprises
The first filter circuit: its input termination alternating current, carries out exporting after filtering to described alternating current;
Isolated buck circuit: be connected with the output of described the first filter circuit, described filtered supply voltage is carried out to step-down processing;
The first square wave generative circuit: be connected with the output of described isolated buck circuit, convert the supply voltage after described step-down to square-wave signal by sine wave signal, described square-wave signal is the reference square wave of power supply voltage;
The signal square wave generative circuit of described residual current, comprises residual current sensor circuit, signal condition change-over circuit, the second filter circuit, the elementary amplifying circuit of signal, signal secondary amplification circuit and the second square wave generative circuit, wherein:
Residual current sensor circuit: its input is connected on circuit to be measured, for the residual current of induction line;
Signal condition change-over circuit: the output of residual current sensor circuit described in its input termination, after being converted to voltage signal, exports residual current signal;
The second filter circuit: the output of signal condition change-over circuit described in its input termination, carries out described voltage signal to export after filtering;
The elementary amplifying circuit of signal: the voltage signal after the conversion of residual current signal is raised to the reference voltage place at 0.5 times, make this voltage signal have complete sinusoidal waveform, the elementary amplifying circuit of described signal comprises two inputs and an output, the first input end of the elementary amplifying circuit of described signal connects the output of described the second filter circuit, and second of the elementary amplifying circuit of described signal is inputted the reference voltage of 0.5 times of termination;
Signal secondary amplification circuit: the voltage signal after the elementary amplifying circuit of described signal is amplified amplifies again, described signal secondary amplification circuit comprises two inputs and two outputs, the first input end of described signal secondary amplification circuit connects the output of the elementary amplifying circuit of described signal, and second of described signal secondary amplification circuit is inputted the reference voltage of 0.5 times of termination;
The second square wave generative circuit: the voltage after described signal secondary amplification circuit is amplified converts square-wave signal to by sine wave signal, described the second square wave generative circuit comprises two inputs and an output, the first input end of described the second square wave generative circuit connects the first output of described signal secondary amplification circuit, second of described the second square wave generative circuit is inputted the reference voltage of 0.5 times of termination, the signal square wave that the output signal of described output is described residual current;
Described controller, comprises
AD converting unit: for detection of the size of residual current, comprise an AD conversion mouth and the 2nd AD conversion mouthful, a described AD conversion mouth connects the output of the elementary amplifying circuit of described signal, and described the 2nd AD conversion mouth connects the second output of described signal secondary amplification circuit;
Interrupt location, comprise for receive power supply voltage reference square wave the first fracture and for receiving signal square wave second fracture of residual current, in described first, fracture connects the output of described the first square wave generative circuit, and fracture connects the output of described the second square wave generative circuit in described second;
Timing unit, record fracture in the reference square wave and described second that fracture in described first receives described power supply voltage and receive the rising edge of signal square wave or the time difference of trailing edge of described residual current, the phase difference that residual current lags behind benchmark phase obtains by formula φ=2 π tl/Tl, Tl is power frequency period, by the square wave after reference signal shaping, start timing, square wave after residual current signal shaping stops timing, between institute's timing, is tl.
2. the phase discriminator of residual current phase place according to claim 1; it is characterized in that; the signal square wave generative circuit of described residual current also comprises protective circuit; signal condition change-over circuit described in the input termination of described protective circuit, the second filter circuit described in the output termination of described protective circuit.
3. the phase discriminator of residual current phase place according to claim 2, it is characterized in that, described the first filter circuit comprises piezo-resistance U1, common mode inductance T1, capacitor C 1, alternating current connects the two ends of described piezo-resistance U1, and two inputs of common mode inductance T1 described in two terminations of described piezo-resistance U1 connect the input of described isolated buck circuit jointly after two outputs of described common mode inductance T1 are connected with the two ends of described capacitor C 1.
4. according to the phase discriminator of claim 1 or 2 or 3 arbitrary described residual current phase places, it is characterized in that, described isolated buck circuit comprises two winding transformer S1.
5. the phase discriminator of residual current phase place according to claim 4, it is characterized in that, described the first square wave generative circuit comprises resistance R 1, R2, R3, R4, capacitor C 2, diode D1, triode Q1, the output of described isolated buck circuit is connected with the base stage of described triode Q1 by resistance R 1, described capacitor C 2, diode D1, after resistance R 2 is in parallel, an end is connected on the link of described resistance R 1 and described triode Q1 base stage, ground connection after the other end is connected with the emitter of described triode Q1, the collector electrode of described triode Q1 connects one end of described resistance R 3, another termination DC power supply of described resistance R 3, one end of described resistance R 4 is connected on the collector electrode of described triode Q1 and the link of described resistance R 3, the other end of described resistance R 4 and described controller first in fracture be connected.
6. the phase discriminator of residual current phase place according to claim 5, is characterized in that, described residual current sensor circuit comprises zero sequence current mutual inductor.
7. the phase discriminator of residual current phase place according to claim 6, is characterized in that, described signal condition change-over circuit comprises resistance R 5.
8. the phase discriminator of residual current phase place according to claim 7, it is characterized in that, described the second filter circuit comprises capacitor C 3, and the two ends of described capacitor C 3 connect the first input end of the output of described signal condition change-over circuit, the elementary amplifying circuit of described signal simultaneously.
9. the phase discriminator of residual current phase place according to claim 1, it is characterized in that, the elementary amplifying circuit of described signal comprises resistance R 6, R7, R8, R9, capacitor C 4, operational amplifier U1C, the first output of one termination the second filter circuit of described resistance R 6, the reverse input end of operational amplifier U1C described in another termination, second output that connects the second filter circuit of described resistance R 7 one end, the input in the same way of operational amplifier U1C described in another termination, between the output of described operational amplifier U1C and reverse input end, be connected described resistance R 8, described output connects described signal secondary amplification circuit first input end simultaneously, the one AD conversion mouthful, the link of the input in the same way of resistance R 7 and described operational amplifier U1C described in one termination of described capacitor C 4, the other end ground connection of described capacitor C 4, the link of the input in the same way of resistance R 7 and described operational amplifier U1C described in one termination of described resistance R 9, the reference voltage that another termination is 0.5 times.
10. the phase discriminator of residual current phase place according to claim 1, is characterized in that, described signal secondary amplification circuit comprises resistance R 10, R11, R12, R13, capacitor C 5, C6, operational amplifier U1D, the reverse input end of described operational amplifier U1D is connected with the output of the elementary amplifying circuit of described signal by described resistance R 10, the input in the same way of described operational amplifier U1D connects the reference voltage of 0.5 times by described resistance R 11, between the input in the same way of described operational amplifier U1D and reverse input end, be connected capacitor C 5, between the output of described operational amplifier U1D and reverse input end, by described resistance R 12, be connected, the output of described operational amplifier U1D is connected with the first input end of described the second square wave generative circuit, the output of described operational amplifier U1D ground connection again after being connected with described capacitor C 6 by described resistance R 13, described resistance R 13 is changed mouth with termination the 2nd AD that is connected of described capacitor C 6.
The phase discriminator of 11. residual current phase places according to claim 1, is characterized in that, described the second square wave generative circuit comprises resistance R 14, R15, operational amplifier U1B; The input in the same way of described operational amplifier U1B is connected with the first output of described signal secondary amplification circuit by described resistance R 14, the reverse input end of described operational amplifier U1B connects the reference voltage of 0.5 times, and the output of described operational amplifier U1B connects fracture in described second by described resistance R 15.
The phase discriminator of 12. residual current phase places according to claim 1, is characterized in that, described controller is single-chip microcomputer.
The phase discriminator of 13. residual current phase places according to claim 2; it is characterized in that; described protective circuit comprises diode D2, D3; ground connection after the negative pole of described diode D2 is connected with the positive pole of described diode D3; the positive pole of described diode D2 connects the negative pole of described diode D3, and jointly connects the output of described signal condition change-over circuit.
The phase discriminator of 14. residual current phase places according to claim 1, is characterized in that, the operating voltage that described reference voltage is controller.
15. according to the phase discriminator of the residual current phase place described in claim 12 or 14, it is characterized in that, the operating voltage of single-chip microcomputer is 5V.
16. according to the phase discriminator of the residual current phase place described in claim 12 or 14, it is characterized in that, the operating voltage of single-chip microcomputer is 3.3V.
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| CN105510713B (en) * | 2014-09-26 | 2018-06-22 | 中微半导体设备(上海)有限公司 | Phase comparator and phase difference monitoring device |
| CN105403742B (en) * | 2015-11-27 | 2018-03-16 | 浙江八达电子仪表有限公司 | Single-phase intelligent electric energy meter based on real-time collection residual current technology |
| CN106532636A (en) * | 2016-11-29 | 2017-03-22 | 快意电梯股份有限公司 | Automatic detection circuit and detection method of brake circuit |
| CN106685234B (en) * | 2017-02-09 | 2023-10-17 | 百色学院 | Voltage-reducing type direct-current switch voltage-stabilizing power supply and voltage-stabilizing control method |
| CN107707223A (en) * | 2017-08-31 | 2018-02-16 | 博罗县节能协会 | A kind of ultra-micro power consumption power lock phase square-wave generator |
| CN116995612A (en) * | 2022-04-24 | 2023-11-03 | 浙江正泰电器股份有限公司 | Residual current operated circuit breaker |
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| JPS63304174A (en) * | 1987-06-04 | 1988-12-12 | Nissin Electric Co Ltd | Zero-phase current detecting method |
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| CN2388755Y (en) * | 1999-08-04 | 2000-07-19 | 张宝明 | Digital phase and amplitude discriminating leakage protector |
| CN202333741U (en) * | 2011-11-25 | 2012-07-11 | 佛山市佛电电器有限公司 | Intelligent lightning protection residual current circuit breaker |
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