CN205646778U - Converter output current detection circuitry - Google Patents
Converter output current detection circuitry Download PDFInfo
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- CN205646778U CN205646778U CN201620249719.3U CN201620249719U CN205646778U CN 205646778 U CN205646778 U CN 205646778U CN 201620249719 U CN201620249719 U CN 201620249719U CN 205646778 U CN205646778 U CN 205646778U
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Abstract
The utility model discloses a converter output current detection circuitry, this circuit include a hall sensor, the 2nd hall sensor, opposition operational amplifier, additive operation ware, opposition arithmetic unit, and it do not has double -phase power cord to pass to divide equally among a hall sensor, the 2nd hall sensor, and pass mutually the same in the double -phase power cord in only having a looks power cord and pass the 2nd hall sensor in a hall sensor's the double -phase power cord, a hall sensor exports first detected signal, and the 2nd hall sensor output second detected signal, first detected signal and second detected signal obtain phase 1 enzyme current signal and phase 2 enzyme current signal respectively after opposition operational amplifier calculates, and phase 1 enzyme current signal and phase 2 enzyme electric current signal input pass through an opposition arithmetic unit to the additive operation ware again, obtain the three phase current signal. The utility model discloses still can realize alternately and relatively short -circuit protection of output, have simple structure, advantage with low costs.
Description
Technical field
This utility model relates to current detecting research field, particularly to a kind of output current of frequency converter detection electricity
Road.
Background technology
At present, the detection of output current of frequency converter typically uses structures below: use three Hall elements
Or three-phase output electric current U, V, W of converter is detected by diverter (A, B, C) respectively,
Structure sees Fig. 1.Each power line is respectively provided with a Hall element or diverter.Use this
Method, can detect the size of three-phase output electric current, carry out the short circuit between phase and phase of U, V, W three-phase
Protection and the short-circuit protection of three-phase (PE) ground-to-ground.
In actual applications, to three-phase output electric current size detect time, add up to according to three-phase current
The principle of zero, it is only necessary to detect any of which biphase current, another phase is the most available by calculating.Separately
Outward, U, V, W three-phase short-circuit protection between phase and phase specifically refer to detect U Yu V or U Yu W or
V with W is the most short-circuit, and this phase fault has only to detect the most biphase equally.But, carry out
The short-circuit protection of U, V, W three-phase (PE) the most over the ground, needs all there is Hall current detection above three-phase
Realizing, seeing Fig. 2, if only arranging Hall element (A, B) on the power line that U, V are biphase
Carry out current detecting, then during W relative ground circuit, will be unable to protection, be easily caused converter and damage.Based on this
Point considers, although size and the phase fault protection of three-phase output electric current can realize with 2 sensors,
But but can not accomplish the three-phase output protection to PE short circuit.Therefore general existing converter still uses three
Sensor, i.e. U, respectively with a sensor above V, W three-phase.
Utility model content
The purpose of this utility model is that the shortcoming overcoming prior art is with not enough, it is provided that a kind of converter output
Current detection circuit, only with two Hall elements in this testing circuit, can realize the inspection of three-phase current
Survey, alternate and relatively short-circuit protection can be realized again, provide cost savings.
The purpose of this utility model is realized by following technical scheme: output current of frequency converter testing circuit,
Including the first Hall element, the second Hall element, rp-op amp, adder calculator, anti-phase
Arithmetical unit, described first Hall element, the second Hall element there is two-phase power supply line to pass respectively,
And only have a phase power line and through the second Hall element in the two-phase power supply line of the first Hall element
In two-phase power supply line in one mutually identical；First Hall element output the first detection signal, the second Hall
Sensor output the second detection signal, the first detection signal and the second detection signal inverted operation amplifier respectively
The first phase current signal and the second phase current signal, described first phase current signal and second is obtained after device computing
Phase current signal is input to adder calculator again through an anti-phase arithmetical unit, obtains third phase current signal.This reality
With novel by such scheme, only with two Hall elements, i.e. achieve the detection of three-phase current, again
Realize alternate and relatively short-circuit protection, the advantage with low cost.
Preferably, between described first Hall element and rp-op amp, the second Hall element and
Being equipped with the first voltage lifting circuit between rp-op amp, described first voltage lifting circuit is used for handle
In first detection signal and the second detection signal, original sinusoidal wave lifting on the basis of 0V is with 2.5V as base
Accurate sine wave.
Preferably, described output current of frequency converter testing circuit also includes comparison circuit, described first phase current
Signal, the second phase current signal, third phase current signal are separately input to comparison circuit, and comparison circuit is used for
By the first phase current signal, the second phase current signal, third phase current signal respectively with default overcurrent protection
Threshold value compares, and stream once occurred, then send control signals to the CPU of converter, and then trigger frequency conversion
Device short-circuit protection circuit carries out short-circuit protection.
Further, being provided with the second voltage lifting circuit before described comparison circuit, described second voltage is lifted
Rise circuit for original with 0V in the first phase current signal, the second phase current signal, third phase current signal
On the basis of sinusoidal wave lifting be the sine wave on the basis of 2.5V.
This utility model compared with prior art, has the advantage that and beneficial effect:
The detection of existing inverter current and overcurrent protection (especially U, V, W tri-relative ground circuit protection)
Realize with three Hall elements, and this utility model only need to use two Hall elements to realize,
Each Hall element is each passed through two output leads, and wherein a phase output will be also cross two Halls
Sensor, can obtain U, V, W three-phase by corresponding relation according to the measured value of Hall element and export
Electric current and carry out three relative ground circuit protections, provides cost savings, makes system more simplify.
Accompanying drawing explanation
Fig. 1 is that in the detection of existing inverter current, the one of which annexation of Hall element and power line is shown
It is intended to.
Fig. 2 is Hall element and the wherein another kind of annexation of power line in the detection of existing inverter current
Schematic diagram.
Fig. 3 is that in this utility model embodiment 1 current detecting, the annexation of Hall element and power line is shown
It is intended to.
Fig. 4 is the circuit diagram of this utility model embodiment 1 current detection circuit.
Fig. 5 is to utilize adder calculator to obtain the circuit diagram of third phase electric current in this utility model embodiment 1.
Fig. 6 is that in this utility model embodiment 2 current detecting, the annexation of Hall element and power line is shown
It is intended to.
Fig. 7 is that in this utility model embodiment 3 current detecting, the annexation of Hall element and power line is shown
It is intended to.
Detailed description of the invention
Below in conjunction with embodiment and accompanying drawing, this utility model is described in further detail, but this utility model
Embodiment be not limited to this.
Embodiment 1
As it is shown on figure 3, the present embodiment output current of frequency converter testing circuit include the first Hall element A,
Second Hall element B, the first Hall element A through the U phase in U, V, W three-phase power line and
V phase, the second Hall element B is through the W phase in U, V, W three-phase power line and V phase, by this
Circuit can realize current detecting and two functions of short-circuit protection, carries out it specifically below in conjunction with circuit diagram
Bright.
One, current detecting
See Fig. 4 and Fig. 5, as a example by the first Hall element A, the first Hall element A output first
Detection signal, this detection signal first passes through the first voltage lifting circuit of the compositions such as R569, R570, the first electricity
Pressure lifting circuit was originally put the first detection signal centered by 0V and was lifted to the voltage of point centered by 2.5V
The sinusoidal wave lifting of waveform reference is the sine wave on the basis of 2.5V.Then anti-phase computing is sent signal to
Amplifier IC505, obtains the first phase current signal after inverted operational amplifier computing, and this signal is W phase
Current signal.
In like manner, the second Hall element B first passes through the first voltage lifting electricity of the compositions such as R603, R604
Road, obtains the second phase current signal after being then passed through the computing of rp-op amp MC34074, this signal
For U phase current signal.
After obtaining W phase current signal and U phase current signal, use the circuit shown in Fig. 5, two-way is believed
Number it is input to after adder calculator again through an anti-phase arithmetical unit, obtains third phase current signal, i.e. V phase current
Signal.
So far, the present embodiment, only with two Hall elements, i.e. achieves the detection of three-phase current, permissible
The current signal obtained is sent to the operations such as the controller storage for current signal of outside, detection.
Two, short-circuit protection
After obtaining three-phase current through foregoing circuit, it is also possible to carry out U, V, W three-phase phase and phase further
Between the short-circuit protection of short-circuit protection and three relatively (PE).Short-circuit protection is realized by comparison circuit.
See Fig. 4, as a example by the first Hall element A, after detection obtains W phase current, first pass through second
Voltage lifting circuit (including R535, R544, R536 etc.), the second voltage lifting circuit is W phase current
In signal, original sinusoidal wave lifting on the basis of 0V is the sine wave on the basis of 2.5V, is then input to
Comparison circuit (IC501 see in figure), comparison circuit is by W phase current signal and the overcurrent protection threshold value preset
Compare, if it exceeds overcurrent protection threshold value, then send control signals to the CPU of converter, and then trigger
Converter short-circuit protection circuit carries out short-circuit protection.
In like manner, after the second Hall element B detection obtains U phase current, first pass through the second voltage lifting electricity
Road (includes R609, R610, R611 etc.), the second voltage lifting circuit in U phase current signal by originally
Centered by 0V, point is lifted to centered by 2.5V the voltage waveform of point, be then input to comparison circuit (see
IC502 in figure), U phase current signal is compared by comparison circuit with the overcurrent protection threshold value preset, if
Exceed overcurrent protection threshold value, then send control signals to the CPU of converter, and then trigger converter short circuit guarantor
Protection circuit carries out short-circuit protection.
By the present embodiment, phase fault and relatively (PE) short circuit all can detect, it is achieved that
Only carry out short-circuit protection with two Hall elements, the advantage with simple in construction, low cost.
Embodiment 2
The present embodiment in addition to following characteristics other structures with embodiment 1:
In embodiment 1, the first Hall element A passes the U phase in U, V, W three-phase power line and V
Phase, the second Hall element B is through the W phase in U, V, W three-phase power line and V phase, the present embodiment
In, seeing Fig. 6, the first Hall element A passes U phase and W phase, and output the first detection signal is-V,
Second Hall element B pass W phase and V phase, output second detection signal-U, by use Fig. 4,5
Shown circuit, can obtain U, V, W three-phase current signal, and then can realize according to three-phase current signal short
Road is protected.
Embodiment 3
The present embodiment in addition to following characteristics other structures with embodiment 1:
In the present embodiment, seeing Fig. 7, the first Hall element A passes U phase and W phase, output the first inspection
Surveying signal is-V, and the second Hall element B passes U phase and V phase, output the second detection signal-W, leads to
Cross employing Fig. 4, circuit shown in 5, U, V, W three-phase current signal can be obtained, and then can be according to three-phase
Current signal realizes short-circuit protection.
Above-described embodiment is this utility model preferably embodiment, but embodiment of the present utility model is not
Being restricted to the described embodiments, any of other is made without departing from spirit of the present utility model and principle are lower
Change, modify, substitute, combine, simplify, all should be the substitute mode of equivalence, be included in this practicality
Within novel protection domain.
Claims (4)
1. output current of frequency converter testing circuit, it is characterized in that, including the first Hall element, the second Hall element, rp-op amp, adder calculator, anti-phase arithmetical unit, described first Hall element, the second Hall element have two-phase power supply line to pass respectively, and through the first Hall element two-phase power supply line in only have a phase power line mutually identical with through in the two-phase power supply line in the second Hall element；First Hall element output the first detection signal, second Hall element output the second detection signal, the first phase current signal and the second phase current signal is obtained after first detection signal and the second detection signal the most inverted operational amplifier computing, described first phase current signal and the second phase current signal are input to adder calculator again through an anti-phase arithmetical unit, obtain third phase current signal.
Output current of frequency converter testing circuit the most according to claim 1, it is characterized in that, being equipped with the first voltage lifting circuit between described first Hall element and rp-op amp, between the second Hall element and rp-op amp, described first voltage lifting circuit is the sine wave on the basis of 2.5V for the first detection signal and second are detected original sinusoidal wave lifting on the basis of 0V in signal.
Output current of frequency converter testing circuit the most according to claim 1 and 2; it is characterized in that; described output current of frequency converter testing circuit also includes comparison circuit; described first phase current signal, the second phase current signal, third phase current signal are separately input to comparison circuit; comparison circuit is for comparing the first phase current signal, the second phase current signal, third phase current signal with default overcurrent protection threshold value respectively; once there is stream; then send control signals to the CPU of converter, and then triggering converter short-circuit protection circuit carries out short-circuit protection.
Output current of frequency converter testing circuit the most according to claim 3, it is characterized in that, being provided with the second voltage lifting circuit before described comparison circuit, it is the sine wave on the basis of 2.5V that described second voltage lifting circuit is used for the sinusoidal wave lifting on the basis of 0V original in the first phase current signal, the second phase current signal, third phase current signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620249719.3U CN205646778U (en) | 2016-03-28 | 2016-03-28 | Converter output current detection circuitry |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620249719.3U CN205646778U (en) | 2016-03-28 | 2016-03-28 | Converter output current detection circuitry |
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| CN205646778U true CN205646778U (en) | 2016-10-12 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105655982A (en) * | 2016-03-28 | 2016-06-08 | 广州七喜智能设备有限公司 | Frequency converter output current detection circuit and detection method thereof |
| CN106711954A (en) * | 2017-03-10 | 2017-05-24 | 常熟理工学院 | Fast-response over-current and short-circuit protection circuit |
-
2016
- 2016-03-28 CN CN201620249719.3U patent/CN205646778U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105655982A (en) * | 2016-03-28 | 2016-06-08 | 广州七喜智能设备有限公司 | Frequency converter output current detection circuit and detection method thereof |
| CN105655982B (en) * | 2016-03-28 | 2018-10-30 | 广州七喜智能设备有限公司 | Output current of frequency converter detection circuit and its detection method |
| CN106711954A (en) * | 2017-03-10 | 2017-05-24 | 常熟理工学院 | Fast-response over-current and short-circuit protection circuit |
| CN106711954B (en) * | 2017-03-10 | 2019-05-17 | 常熟理工学院 | A kind of fast-response short circuit over-current protection circuit |
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