CN211505710U - Three-phase alternating current power supply phase-missing detection and protection circuit - Google Patents
Three-phase alternating current power supply phase-missing detection and protection circuit Download PDFInfo
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- CN211505710U CN211505710U CN201921491900.5U CN201921491900U CN211505710U CN 211505710 U CN211505710 U CN 211505710U CN 201921491900 U CN201921491900 U CN 201921491900U CN 211505710 U CN211505710 U CN 211505710U
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Abstract
The three-phase AC power supply phase error and loss detection and protection circuit firstly rectifies a three-phase power supply into square waves, differentiates the square waves to extract pulse signals along the rising edge of the current-phase square waves, compares every two square waves by using a NAND gate to detect the correctness of a phase sequence, and then detects whether the NAND gate outputs the pulse signals by using an integrating circuit to judge whether the whole three-phase power supply has the error and the phase loss or not, in the circuit, a normally open switch of a relay can be directly connected in a power supply and distribution control circuit of a three-phase AC motor to control the on-off of a motor power supply, when the phase sequence of the three-phase power supply is correct, the normally open switch of the relay is closed, the motor is connected with the power supply, and when the three-phase power supply has the error and the phase loss, the normally open switch of the relay is kept open, the motor is not connected with, the detection is quick and accurate, the whole circuit can be directly integrated into a power supply and distribution control circuit, the use is very convenient, and the applicability is wide.
Description
Technical Field
The utility model relates to a distribution technical field especially indicates a three-phase alternating current power supply mistake lacks looks detection and protection circuit.
Background
As is known, the power supply for a three-phase ac motor needs to ensure that the three-phase power supply does not lack a phase and the phase sequence is correct, otherwise the rotation direction of the motor is not controllable or the motor is easily damaged. At present, the three-phase power supply phase fault and loss detection circuit technology is mature, the applicable technical principles are more, a three-phase power supply phase sequence vector method, a three-phase detection special integrated circuit or a single chip microcomputer is adopted for programming, and the like, however, the detection technologies exist in practical application, are finished products and are used for independently detecting the phase fault and loss of the three-phase power supply, the integration of the detection technologies in a power supply and distribution control circuit is inconvenient, and some peripheral circuits need to be added.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a simple convenience is integrated to the three-phase alternating current power supply mistake phase failure detection and protection circuit among the power supply and distribution control circuit.
In order to solve the technical problem, the utility model discloses a following technical scheme: the utility model provides a three-phase alternating current power supply mistake lacks looks detection and protection circuit, includes A looks half-wave rectifier circuit, B looks half-wave rectifier circuit, C looks half-wave rectifier circuit, first differential circuit, second differential circuit, NAND gate U4: B. nand gate U4: C. the input end of the A-phase half-wave rectifying circuit is electrically connected with the A phase, the output end of the A-phase half-wave rectifying circuit is respectively connected with the first differential circuit and the second differential circuit, the input end of the B-phase half-wave rectifying circuit is electrically connected with the B phase, and the output end of the B-phase half-wave rectifying circuit is connected with the NAND gate U4 after phase reversal: the input end of B is connected, the input end of the C-phase half-wave rectification circuit is electrically connected with C phase, and the output end of the C-phase half-wave rectification circuit is connected with an NAND gate U4: c, the nand gate U4: b, the other input end of the nand gate U4 is connected to a first differential circuit: the output end of B is connected with a first integral discharge circuit, and the NAND gate U4: the other input end of the NAND gate U4 is connected into a second differential circuit: the output of C is connected with second integral discharge circuit, first integral discharge circuit, second integral discharge circuit all are connected with triode V1's base, termination in triode V2's base behind triode V1's the projecting pole opposition, triode V2 is connected with relay J1 and alarm circuit respectively, and when triode V2 switched on, relay J1's coil circular telegram, relay J1's normally open switch is closed, and when triode V2 disconnection, alarm circuit sends alarm signal.
Further, this three-phase alternating current power supply mistake lacks looks detection and protection circuit still includes opto-coupler U1, opto-coupler U2, opto-coupler U3, the input of opto-coupler U1 is connected with the output of B looks half-wave rectifier circuit, the output of opto-coupler U1 and NAND gate U4: the input end of B is connected, the input end of opto-coupler U2 is connected with the output end of A looks half-wave rectifier circuit, the output end of opto-coupler U2 is connected with first differential circuit and second differential circuit respectively, the input end of opto-coupler U3 is connected with the output end of C looks half-wave rectifier circuit, the output end of opto-coupler U3 and NAND gate U4: the input end of the C is connected, and the output ends of the optical coupler U1, the optical coupler U2 and the optical coupler U3 are respectively provided with a pull-down resistor R6, a pull-down resistor R5 and a pull-down resistor R4.
Furthermore, the first differential circuit comprises a capacitor C2 and a resistor R9, and the output end of the optocoupler U2 is connected to a nand gate U4: a rear end is connected with one end of a capacitor C2, one end of the resistor R9 is connected with the other end of the capacitor C2, the other end of the resistor R9 is grounded, and the nand gate U4: one output end of the B is connected between the capacitor C2 and the resistor R9; the second differential circuit comprises a capacitor C1 and a resistor R7, one end of the capacitor C1 is connected with the output end of an optocoupler U2, the other end of the capacitor C1 is connected with one end of a resistor R7, the other end of the resistor R7 is grounded, and the NAND gate U4: one input terminal of C is connected between the capacitor C1 and the resistor R7.
Further, the first integral discharge circuit includes a diode D7, a resistor R10, and a capacitor C4, and a cathode of the diode D7 is connected to a nand gate U4: the output end of B is connected, the positive pole of diode D7 is connected with resistance R10 and electric capacity C4 respectively, resistance R10 is connected with the power, electric capacity C4 ground connection, the second integral discharge circuit includes diode D5, resistance R8 and electric capacity C3, the negative pole and NAND gate U4 of diode D5: the output end of C is connected, diode D5's positive pole is connected with resistance R8 and electric capacity C3 respectively, resistance R8 connects the power VCC, electric capacity C3 ground connection, diode D7 and diode D5's positive pole still all are connected with triode V1's base.
Still further, alarm circuit includes resistance R12 and emitting diode D10, the power VCC is inserted to resistance R12's one end, resistance R12's the other end and emitting diode D10's anodal connection, be connected with emitting diode D10's negative pole and triode V2's base respectively behind triode V1's the projecting pole opposition, triode V2's projecting pole ground connection, relay J1's coil one end is connected in the power VCC, and the other end is connected with triode V2's collecting electrode, just relay J1's coil and a diode D11 are parallelly connected.
Preferably, the output end of the optocoupler U2 adopts a NAND gate U4: a is inverted, and the emitter of the triode V1 adopts a NAND gate U4: d is inverted and the emitter of the transistor V1 also pulls down a resistor R11.
The utility model provides a three-phase AC power supply mistake phase-missing detection and protection circuit, utilize the rising edge of current looks square wave in the preceding looks square wave and the characteristic of the falling edge of current looks square wave in the latter looks square wave to judge the phase sequence of three-phase power supply, concretely speaking, this circuit is earlier three-phase power supply rectification square wave, carry out the differentiation with the square wave and propose the rising edge pulse signal of current looks square wave and adopt NAND gate to two pairs of square waves to compare and detect the exactness of phase sequence, whether utilize integrating circuit detection NAND gate output pulse signal, whether whole three-phase power supply has the mistake, the phase-missing, in this circuit, the design has the relay, its normally open switch can directly connect in the distribution control circuit of three-phase AC motor, in order to control the break-make of motor power, when three-phase power supply phase sequence is exact, the normally open switch of relay is closed, three-phase AC motor switch-on three-phase power, when the three-phase power supply is in a wrong phase or a phase loss, the normally open switch of the relay is kept disconnected, the motor cannot be connected with the three-phase power supply, and the light emitting diode in the circuit gives an alarm to warn a worker that the phase sequence of the three-phase power supply has the wrong phase or the phase loss.
Comprehensively, the utility model provides a three-phase alternating current power supply mistake lacks looks and detects and protection circuit adopts a slice 42 input and non-gate number sub-integrated circuit just can realize lacking looks and detecting three phase current's mistake, simple structure, and it is quick, accurate to detect, and whole circuit can directly integrate to supplying power distribution control circuit in, and it is very convenient to use, extensive applicability.
Drawings
FIG. 1 is a circuit diagram of the three-phase AC power supply phase-missing detection and protection circuit of the present invention;
FIG. 2 is a square wave phase sequence diagram of the half-wave rectification of the phase A, phase B and phase C of the present invention;
fig. 3 shows a nand gate U4: b, inputting and outputting a signal waveform diagram;
fig. 4 shows a nand gate U4: and C, inputting and outputting a signal waveform diagram.
Detailed Description
In order to facilitate understanding of those skilled in the art, the present invention will be further described with reference to the following examples and drawings, which are not intended to limit the present invention.
The utility model provides a three-phase alternating current power supply mistake lacks looks detection and protection circuit, includes A looks half-wave rectifier circuit, B looks half-wave rectifier circuit, C looks half-wave rectifier circuit, first differential circuit, second differential circuit, NAND gate U4: B. nand gate U4: C. first integral discharge circuit, second integral discharge circuit, triode V1, triode V2, relay J1 and warning circuit, the input and the A looks electricity of A looks half-wave rectifier circuit are connected, and the output is connected with first differential circuit and second differential circuit respectively, and the input and the B looks electricity of B looks half-wave rectifier circuit are connected, and with NAND gate U4 behind the output phase reversal: the input end of B is connected, the input end of C looks half-wave rectifier circuit is connected with C looks electricity, the output and NAND gate U4: c, an input end of the NAND gate U4: the other input end of the B is connected into a first differential circuit, and a NAND gate U4: the output end of B is connected with the first integral discharge circuit, and the NAND gate U4: the other input end of the C is connected into a second differential circuit, and a NAND gate U4: the output end of C is connected with second integral discharge circuit, first integral discharge circuit, second integral discharge circuit all are connected with triode V1's base, triode V1's projecting pole is back-connected in triode V2's base after-phase, triode V2 is connected with relay J1 and alarm circuit respectively, when triode V2 switches on, relay J1's coil circular telegram, relay J1's normally open switch is closed, when triode V2 breaks off, alarm circuit sends alarm signal.
In the three-phase ac power supply phase-miss detection and protection circuit according to the above-mentioned embodiment, the a-phase half-wave rectifier circuit, the B-phase half-wave rectifier circuit, and the C-phase half-wave rectifier circuit are respectively used for half-wave rectifying the a-phase power, the B-phase power, and the C-phase power of the three-phase power supply, specifically, as shown in fig. 1, the diode D2 and the resistor R2 are connected in series to form the a-phase half-wave rectifier circuit, the a-phase power is half-wave rectified, the diode D1 and the resistor R1 are connected in series to form the B-phase half-wave rectifier circuit, the B-phase power is half-wave rectified, the diode D3 and the resistor R3 are connected in series to form the C-phase half-wave rectifier circuit, the C-phase power is half-wave rectified, the a-phase power, the B-phase power, and the C-phase power are half-wave rectified to obtain three-phase phases with a phase difference of 120, the present embodiment is based on this characteristic, and determines the phase sequence of the three-phase power supply by detecting whether the falling edge of the current-phase square wave is in the next-phase square wave. The working principle and process of the three-phase ac power supply phase fault and loss detection and protection circuit in the present embodiment will be described in detail below, which mainly includes four major parts.
A first part: rectifying and isolating
The half-wave rectification process of the a-phase power, the B-phase power and the C-phase power of the three-phase power supply is mentioned above, and is not described herein again. In order to prevent the interference caused by the connection of electricity between the low-voltage control circuit and the high-voltage circuit of the three-phase power supply, the A-phase electricity, the B-phase electricity and the C-phase electricity are rectified and then electrically isolated, the isolating device is an optical coupler U1, an optical coupler U2 and an optical coupler U3, the input end of the optical coupler U1 is connected with a resistor R1, and the output end of the optical coupler U1 is connected with a NAND gate U4: the input end of the B is connected with a pull-down resistor R6, the phase B is subjected to half-wave rectification and isolation by the optocoupler U1, and phase information of the phase B is transmitted to a resistor R6; the input end of the optocoupler U2 is connected with the resistor R2, the output end of the optocoupler U2 is respectively connected with the first differential circuit and the second differential circuit, the resistor R5 is pulled down, and phase A electricity is isolated by the optocoupler U2 after half-wave rectification, and phase information of the phase A electricity is transmitted to the resistor R5; the input end of the optocoupler U3 is connected with the resistor R3, and the output end of the optocoupler U3 is connected with the NAND gate U4: the input end of the C is connected, the resistor R4 is pulled down, the C phase power is isolated by the optocoupler U3 after half-wave rectification, and phase information of the C phase power is transmitted to the resistor R4.
A second part: square wave signal differentiation, comparison (correctness of phase sequence detection)
1. In fig. 1, a capacitor C2 and a resistor R9 form a first differential circuit, and the output end of an optocoupler U2 is connected to a nand gate U4: the rear end of the resistor R9 is connected with one end of a capacitor C2, one end of a resistor R9 is connected with the other end of a capacitor C2, the other end of the resistor R9 is grounded, a diode D6 and an NAND gate U4 can be connected to the resistor R9 in parallel: an output terminal of B is connected between the capacitor C2 and the resistor R9. Nand gate U4: a, inverting the phase of the square wave signal on the resistor R5, extracting a falling edge signal of the square wave signal on the resistor R5 through a differential circuit consisting of a capacitor C2 and a resistor R9, and sending the falling edge signal to a NAND gate U4: after B, the phase B is compared with the square wave signal on the resistor R6 (i.e. the square wave signal of the phase B power), if the phase B power is after the phase a power, the pulse signal as shown in fig. 3 is output, otherwise, both the phase loss and the phase sequence error output a high level.
2. In fig. 1, a capacitor C1 and a resistor R7 form a second differential circuit, one end of a capacitor C1 is connected with an output end of an optocoupler U2, the other end of the capacitor C1 is connected with one end of a resistor R7, the other end of the resistor R7 is grounded, a diode D4 and a nand gate U4 can be further connected in parallel to the resistor R7: one input terminal of C is connected between the capacitor C1 and the resistor R7. The first differentiating circuit composed of the capacitor C1 and the resistor R7 differentiates the square wave signal on the resistor R5, and the generated rising edge signal pulse is sent to the nand gate U4: in C, compared with the square wave signal on the resistor R4 (i.e., the C-phase power square wave signal), if the C-phase power is before the a-phase power, the nand gate U4: c outputs a pulse signal as shown in fig. 4, otherwise, both the open phase and the phase sequence error output a high level.
And a third part: nand gate U4: b and nand gate U4: c output signal integration (detecting whether to output a pulse signal) 1, a diode D7, a resistor R10 and a capacitor C4 in fig. 1 form a first integration discharge circuit, and the cathode of the diode D7 and the nand gate U4: the output end of the B is connected, the anode of the diode D7 is respectively connected with the resistor R10 and the capacitor C4, the resistor R10 is connected with the power supply, the capacitor C4 is grounded, and the anode of the diode D7 is connected with the base of the triode V1 after being connected with a diode D8. The first integral discharge circuit is used for detecting the voltage of the NAND gate U4: if the output of B is pulse signal, the capacitor C4 is periodically discharged through the diode D7 to be low level, otherwise, the capacitor C4 is charged to be high level through the resistor R10.
2. In fig. 1, a diode D5, a resistor R8 and a capacitor C3 form a second integral discharge circuit, and the cathode of the diode D5 and the nand gate U4: the output end of the resistor C is connected, the anode of the diode D5 is respectively connected with the resistor R8 and the capacitor C3, the resistor R8 is connected with the power VCC, the capacitor C3 is grounded, and the anode of the diode D5 is connected with the base of the triode V1 after being connected with a diode D9. The second integral discharge circuit is used for detecting the voltage of the NAND gate U4: if the output of the capacitor C is a pulse signal, the capacitor C3 is periodically discharged through the diode D5 to be at a low level, otherwise, the capacitor C3 is charged through the resistor R8 to be at a high level.
The fourth part: judging whether the whole circuit is in error or open phase
In fig. 1, both the diode D8 and the diode D9 are connected to a base of a transistor V1(NPN type), a collector of the transistor V1 is connected to a power VCC, an emitter pull-down resistor R11 of the transistor V1, and a nand gate U4: two input ends of the D are connected with an emitting electrode of a triode V1, and the NAND gate U4: an output end of the D is connected with a resistor R13 in series and then connected with a base of a triode V2(NPN type), an emitter of a triode V2 is grounded, one end of a coil of a relay J1 is connected with a collector of the triode V2, the other end of the coil is connected with a power supply VCC, a coil of a relay J1 can be connected with a diode D11 in parallel, a normally open switch of the relay J1 is directly used as a three-phase power supply control switch and connected with a power supply and distribution control circuit of a three-phase alternating current motor, a resistor R12 and a light emitting diode D10 in fig. 1 form an alarm circuit, one end of a resistor R12 is connected with the power supply VCC, the other end of the resistor R12 is connected with an anode of a light emitting: d and resistor R13.
If the phase power of A phase, the phase power of B phase, the phase power of C phase of three-phase power supply are wrong, diode D8 and diode D9 all output high level to triode V1, make triode V1 switch on, be high level on the resistance R11, NAND gate U4: d outputs low level, the triode V2 is not conducted, the coil of the relay J1 is not electrified, the normally open switch of the relay J1 is kept disconnected, and the light emitting diode D10 emits light to give an alarm.
If at least one of the phase A power, the phase B power and the phase C power of the three-phase power supply is in phase failure, at least one of the diode D8 and the diode D9 outputs high level to the triode V1, and similarly, the triode V1 is conducted, the triode V2 is not conducted, the coil of the relay J1 is not electrified, the normally open switch of the relay J1 is kept disconnected, and the light-emitting diode D10 emits light to give an alarm.
If the phase sequence of the phase A power, the phase B power and the phase C power of the three-phase power supply is correct and the phase is not lost, the diode D8 and the diode D9 both output low level to the triode V1, the triode V1 is not conducted, the resistor R11 is low level, and the NAND gate U4: d outputs high level, so that the triode V2 is conducted, the coil of the relay J1 is electrified, the normally open switch of the relay J1 is closed, the three-phase alternating current motor is connected to a three-phase power supply, and normal work can be started.
The above-mentioned embodiment is the utility model discloses the implementation scheme of preferred, in addition, the utility model discloses can also realize by other modes, any obvious replacement is all within the protection scope of the utility model under the prerequisite that does not deviate from this technical scheme design.
In order to make it easier for those skilled in the art to understand the improvement of the present invention over the prior art, some drawings and descriptions of the present invention have been simplified, and in order to clarify, some other elements have been omitted from this document, those skilled in the art should recognize that these omitted elements may also constitute the content of the present invention.
Claims (6)
1. Three-phase alternating current power supply phase failure detection and protection circuit, its characterized in that: the three-phase inverter comprises an A-phase half-wave rectifying circuit, a B-phase half-wave rectifying circuit, a C-phase half-wave rectifying circuit, a first differential circuit, a second differential circuit and an NAND gate U4: B. nand gate U4: C. the input end of the A-phase half-wave rectifying circuit is electrically connected with the A phase, the output end of the A-phase half-wave rectifying circuit is respectively connected with the first differential circuit and the second differential circuit, the input end of the B-phase half-wave rectifying circuit is electrically connected with the B phase, and the output end of the B-phase half-wave rectifying circuit is connected with the NAND gate U4 after phase reversal: the input end of B is connected, the input end of the C-phase half-wave rectification circuit is electrically connected with C phase, and the output end of the C-phase half-wave rectification circuit is connected with an NAND gate U4: c, the nand gate U4: b, the other input end of the nand gate U4 is connected to a first differential circuit: the output end of B is connected with a first integral discharge circuit, and the NAND gate U4: the other input end of the NAND gate U4 is connected into a second differential circuit: the output of C is connected with second integral discharge circuit, first integral discharge circuit, second integral discharge circuit all are connected with triode V1's base, termination in triode V2's base behind triode V1's the projecting pole opposition, triode V2 is connected with relay J1 and alarm circuit respectively, and when triode V2 switched on, relay J1's coil circular telegram, relay J1's normally open switch is closed, and when triode V2 disconnection, alarm circuit sends alarm signal.
2. The three-phase alternating current power supply phase failure detection and protection circuit of claim 1, wherein: the output end of the optocoupler U1 is connected with the output end of the NAND gate U4: the input end of B is connected, the input end of opto-coupler U2 is connected with the output end of A looks half-wave rectifier circuit, the output end of opto-coupler U2 is connected with first differential circuit and second differential circuit respectively, the input end of opto-coupler U3 is connected with the output end of C looks half-wave rectifier circuit, the output end of opto-coupler U3 and NAND gate U4: the input end of the C is connected, and the output ends of the optical coupler U1, the optical coupler U2 and the optical coupler U3 are respectively provided with a pull-down resistor R6, a pull-down resistor R5 and a pull-down resistor R4.
3. The three-phase alternating current power supply phase failure detection and protection circuit of claim 2, wherein: the first differential circuit comprises a capacitor C2 and a resistor R9, and the output end of the optocoupler U2 is connected with a NAND gate U4: a rear end is connected with one end of a capacitor C2, one end of the resistor R9 is connected with the other end of the capacitor C2, the other end of the resistor R9 is grounded, and the nand gate U4: one output end of the B is connected between the capacitor C2 and the resistor R9; the second differential circuit comprises a capacitor C1 and a resistor R7, one end of the capacitor C1 is connected with the output end of an optocoupler U2, the other end of the capacitor C1 is connected with one end of a resistor R7, the other end of the resistor R7 is grounded, and the NAND gate U4: one input terminal of C is connected between the capacitor C1 and the resistor R7.
4. The three-phase alternating current power supply phase failure detection and protection circuit of claim 3, wherein: the first integral discharge circuit comprises a diode D7, a resistor R10 and a capacitor C4, wherein the cathode of the diode D7 is connected with a NAND gate U4: the output end of B is connected, the positive pole of diode D7 is connected with resistance R10 and electric capacity C4 respectively, resistance R10 is connected with the power, electric capacity C4 ground connection, the second integral discharge circuit includes diode D5, resistance R8 and electric capacity C3, the negative pole and NAND gate U4 of diode D5: the output end of C is connected, diode D5's positive pole is connected with resistance R8 and electric capacity C3 respectively, resistance R8 connects the power VCC, electric capacity C3 ground connection, diode D7 and diode D5's positive pole still all are connected with triode V1's base.
5. The three-phase alternating current power supply phase failure detection and protection circuit of claim 4, wherein: alarm circuit includes resistance R12 and emitting diode D10, resistance R12's one end inserts the power VCC, resistance R12's the other end and emitting diode D10's anodal is connected, be connected with emitting diode D10's negative pole and triode V2's base respectively behind triode V1's the projecting pole opposition, triode V2's projecting pole ground connection, relay J1's coil termination is in power VCC, and the other end is connected with triode V2's collecting electrode, just relay J1's coil and a diode D11 are parallelly connected.
6. The three-phase alternating current power supply phase failure detection and protection circuit of claim 5, wherein: the output end of the optocoupler U2 adopts a NAND gate U4: a is inverted, and the emitter of the triode V1 adopts a NAND gate U4: d is inverted and the emitter of the transistor V1 also pulls down a resistor R11.
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| CN201921491900.5U CN211505710U (en) | 2019-09-09 | 2019-09-09 | Three-phase alternating current power supply phase-missing detection and protection circuit |
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| CN201921491900.5U CN211505710U (en) | 2019-09-09 | 2019-09-09 | Three-phase alternating current power supply phase-missing detection and protection circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113671277A (en) * | 2021-08-11 | 2021-11-19 | 都昌县百事网络信息服务有限公司 | Zero-crossing pulse counting phase-loss detection circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113671277A (en) * | 2021-08-11 | 2021-11-19 | 都昌县百事网络信息服务有限公司 | Zero-crossing pulse counting phase-loss detection circuit |
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