CN2506011Y - Three phase AC power source phase sequence automatic monitoring device - Google Patents

Abstract

The utility model relates to a monitoring device for a three-phase AC power supply, in particular to a phase sequence automatic monitoring and control device for a three-phase AC power supply. Part, working state display part, which is installed in the shell as a whole, the front panel of the shell shows the working state, and the rear panel is the input and output terminals. This device has the advantages of simple structure, small size and complete performance. Power supply overvoltage, undervoltage, and lack of phase display alarms, and can be automatically adjusted to ensure that the three-phase AC power supply is always in a normal power supply state, so as to ensure that the three-phase electrical equipment will not be burned or shut down due to incorrect power supply phase sequence. .

Description

Three-phase AC power supply phase sequence automatic monitoring and control device

The utility model relates to a monitoring device for a three-phase AC power supply, in particular to a phase sequence automatic monitoring and control device for a three-phase AC power supply.

At present, most of the monitoring devices for three-phase AC power supply are alarm devices, and their functions are alarm display overvoltage, undervoltage, phase loss, phase sequence identification and phase loss alarm. Automatic monitoring and control cannot be performed. Therefore, it cannot meet the requirements and needs of various electrical equipment on the quality of the power grid.

The purpose of this utility model is to propose a three-phase AC power supply phase sequence automatic monitoring and control device, which can not only alarm the phase sequence, overvoltage, undervoltage, and lack of phase of the three-phase AC power supply, but also automatically monitor and adjust to ensure The three-phase AC power supply is always maintained in the correct power supply state, or the power supply state required by the user. At the same time, it solves the problems such as the incorrect phase sequence caused by the power supply voltage being too high, too low, or lack of phase, which leads to the failure of the electrical equipment to work normally or the burning of the equipment.

The main technical content of the utility model is that the three-phase AC power supply phase sequence automatic monitoring and control device is composed of a phase sequence monitoring part, a lack of phase monitoring part, an overvoltage and undervoltage monitoring part, a three-phase power supply regulation output part, and a working state display part. ;The phase sequence monitoring part consists of piezoresistors TR ₁ , TR ₂ , resistors R ₇ , R ₈ , R ₉ , R ₁₀ , capacitors C ₃ , C ₄ , C ₅ , C ₆ , C ₇ , voltage selection switch K ₁ , Relay JQ ₁ forms a phase sequence three-point balance circuit. The input terminals of A, B, and C three-phases of the three-phase power supply, A phase is connected in series with resistors R ₇ and R ₈ , and resistor R ₉ is connected in series with voltage selection switch K ₁ On resistor R ₈ , phase B is connected in series with capacitors C ₃ , C ₄ , C ₅ , and C ₆ , phase C is connected in series with phase sequence relay JQ ₁ , resistor R ₁₀ is connected in series with C ₇ and connected to both ends of phase sequence relay JQ ₁ , the output terminals of A, B, and C are connected to one point O, the contact point JQ _1-1 of the relay JQ ₁ is connected to the output part of the three-phase power supply regulation between zero and phase voltage, and the phases A, B, and C are respectively connected to There are piezoresistors TR ₁ and TR ₂ ;

The lack of phase monitoring part is composed of a phase loss detection circuit, a phase loss power driving circuit and a power supply circuit. The phase loss detection circuit consists of resistors R ₁ , R ₂ , R ₃ , R ₄ , rectifier diode D ₁ , light emitting diode D ₂ , capacitor C ₁ , the input terminals of the three-phase AC power supply A, B, C are connected in series with R ₁ , R ₂ , R ₃ respectively, the output terminals are connected in parallel and connected in series with the rectifier diode D ₁ and resistor R ₄ , and the phase loss indicator lights up Diode D ₂ and capacitor C ₁ are connected in parallel to O point and the output end of rectifier diode D ₂ , the output of the phase loss detection circuit is connected with the input terminals 1 and 2 of photocoupler circuit A ₃ , the output terminal 4 of photocoupler circuit A ₃ , 5 are connected with the phase loss power driving circuit, the phase loss power driving circuit is composed of resistors R ₅ , R ₆ , relay JQ ₃ , and triode BG _1. One end of R ₅ , R ₆ is connected to terminal 5 of A ₃ , and the end of R ₅ The other end is connected to one end of the relay JQ ₃ , the other end of JQ ₃ is connected to the emitter of BG ₁ , the collector of BG ₁ is connected to the 4 end of A ₃ , the base of BG ₁ is connected to the other end of R ₆ , and the rectifier circuit is composed of transformer B ₁ , rectifier bridge D ₃ , three-terminal voltage regulator A ₄ , and capacitor C ₂ are formed to convert 220V AC into DC voltage to supply phase-loss power to drive the circuit to work, and the normally closed contact JQ _2-1 of relay JQ ₃ is connected to the three-phase power supply Control output part connection;

The overvoltage and undervoltage monitoring part is composed of a sampling circuit, an overvoltage monitoring circuit and an undervoltage monitoring circuit. The sampling circuit is composed of a three-phase series-connected transformer _B2 and a rectifier circuit _D4 . The coil of the three-phase series-connected transformer _B2 L _a , L _b , and L _c are respectively coupled with the three-phase power supplies A, B, and C, and their output terminals are connected to the input terminal of the rectifier bridge D ₄ , and the output terminal of the rectifier bridge is connected to the capacitor C ₈ and the overvoltage adjustable resistor W _1. The undervoltage adjustment resistor W ₂ is connected in parallel. The overvoltage monitoring circuit is composed of the micro-power consumption voltage detection circuit A ₁ , the overvoltage adjustable resistor W ₁ and the resistor R _12. Terminal ② of A ₁ is connected to the overvoltage adjustable resistor W ₁ The adjustable terminal of A ₁ is connected, the output terminal ① of A 1 is connected to R ₁₂ , the other end of R ₁₂ is connected to the B terminal of XOR gate T ₁ , and the ③ of A ₁ is grounded; the undervoltage monitoring circuit is composed of a micro-power consumption voltage detection circuit A ₂ , adjustable resistance W ₂ , composed of resistance R ₁₄ , the input end ② of the micro-power consumption voltage detection circuit A ₂ is connected to the adjustable end of the undervoltage adjustable resistance W ₂ , the output end ① of A ₂ is connected to the end of resistance R ₁₄ connection, the other end of R ₁₄ is connected to the A terminal of the exclusive OR gate, the output terminal of the exclusive OR gate is connected to the input terminal of the NOT gate, and the contact JQ _2-1 of the relay JQ ₂ is connected to the three-phase power regulation between the output terminal of the NOT gate and the ground. output part connection;

The three-phase power control output part consists of relays JC ₁ , JC ₂ , contacts JC _1-1 , JC _1-2 , JC _2-1 , JC _2-2 , auxiliary contacts JC _1-3 , JC _2-3 , and JQ ₁ The contact JQ _1-1 of JQ ₂ , the contact JQ _2-1 of JQ 2, and the contact JQ _3-1 of JQ ₃ , the relay JC ₂ is connected in series with JC _1-3 , JQ _1-1 , JQ _2-1 JQ _3-1 , Both ends are connected between the zero and phase voltage of the output terminal of the three-phase power supply, JC _1-1 and JC _2-1 are connected in parallel with the input terminal A of the three-phase power supply, and JC _1-2 and JC _2-2 are connected in parallel with the three-phase power supply The input end B is connected, and the other end JC _1-1 , JC _2-2 parallel output, JC _1-2 , JC _2-1 parallel output, respectively are three-phase power output;

The working state display part is composed of light-emitting diodes _D5 , _D6 , _D7 , resistor _R15 , contact JQ1-2 of relay JQ1, contact JQ2-2 of _JQ2 , contacts JQ1-2, JQ2-2 and light-emitting diode _D7 One end is connected to ground, the other end of JQ1-2 is connected to light-emitting diode D5, the other end of JQ2-2 is connected to light-emitting diode _D6 , and the other ends of diodes _D5 and _D6 are connected to phase voltage through resistor _R15 .

The whole device is installed in a housing, the front panel displays the working status, and the rear panel is provided with input terminals A, B, C, and 0 output terminals a, b, c, 0.

The working principle of the three-phase AC power phase sequence automatic monitoring and control device:

First, after the three-phase AC power enters the device, it is respectively connected to the phase sequence monitoring, phase loss monitoring, and overvoltage and undervoltage monitoring parts.

1. When the three-phase AC power supply enters the phase-deficiency monitoring part, the resistors R1-R3 are connected in a star-shaped connection to form an analog three-phase symmetrical load. Usually, the balanced three-phase voltage is applied to the analog three-phase through the A, B, and C contacts. On the symmetrical load resistor R1-R3, according to the electrical engineering principle, the voltage of the common contact point of the resistor R1-R3 to the ground (neutral line) O point is zero, so that the light-emitting diode in A3 cannot emit light. When the three-phase AC voltage A, B, C When one of the phases is open or phase-open, the voltage of the common contact of resistors R1-R3 to the ground is half of the voltage of the three-phase line, and the voltage of the common contact to the ground (neutral line) at 0 is 190V, and the voltage is rectified by D1 half-wave Through the photoelectric coupling circuit from R4 to A3, the built-in light-emitting tube is turned on. At this time, the built-in photosensitive tube in A3 is turned on, and the ⑤ pin is at a low potential. The base of BG1 is at a low potential. The contact JQ3-1 of JQ3 in the relay coil is normally closed and becomes normally open, so that the JC relay coil cannot work without voltage (phase loss is protected).

2. Overvoltage and undervoltage monitoring part:

The overvoltage and undervoltage monitoring circuit is shown as III in Figure 1. La, Lb, and Lc in B2 are three-phase series-connected transformers. After the output voltage is rectified by D1-D4 bridge and filtered by C8, it outputs about 10V DC Voltage. On the one hand, this voltage is used as the sampling voltage of the mains fluctuation, and is added to the input terminals of the voltage detection circuit A1 and A2 after passing through W1 and W2. When the voltage is lower than 4.75V, pin ① of the output terminal is at low level. Similarly, the voltage of pin ② of A2 is higher than 4.75V, and pin ① is at high level until the input B terminal of the XOR gate is at high level. When the power supply voltage changes, the output voltage of C8 changes accordingly. If the voltage is too high (overvoltage), the input voltage of A1 will exceed its detection voltage, which is higher than 4.75V, so that the output terminal ① of A1 will change from low level to High level, and when the power supply voltage is low (undervoltage), although the output of A1 does not change, the voltage of the input terminal ② of A2 drops below the detection voltage of 4.75V, and the output terminal ① of A2 changes from high level to low voltage. flat.

When the three-phase power supply is normal: when the input terminal ② of the overvoltage micro-power voltage detection circuit of A1 is "0" potential, the output terminal ① is "0" potential, the a terminal of the XOR gate T1 is "0" potential, and the T2 NOT gate output is low.

At the same time, the input terminal ② of the undervoltage micro-power voltage detection circuit of A2 is "1" potential, the output terminal ① is "1" potential, the b terminal of the XOR gate T1 is "1" potential, the output of the T2 NOT gate is low potential, and the T2 NOT gate output is at a low potential. The gate output low potential JQ2 does not work, and the JQ2 contact JQ2-1, which is connected in series in the JC1 and JC2 coils, is normally closed and does not act.

When the three-phase power supply is overvoltage: when the input terminal ② of the overvoltage micropower voltage detection circuit of A1 is "1" potential, the output terminal ① is "1" potential, the a terminal of the XOR gate T1 is "1" potential, and T2 is not Gate input is "1" potential.

At the same time, the input terminal ② of the undervoltage micro-power consumption voltage detection circuit of A2 is "1" potential, the output terminal ① is "1" potential, the b terminal of the XOR gate T1 is "1" potential, and the input of the NOT gate of T2 is "1" potential. The non-gate output terminal outputs "1" potential JQ2 to work, and the JQ2 contact JQ2-1 connected in series to the JC1 and JC2 coils is switched from normally closed to normally open. At this time, the JC1 and JC2 coil circuits are disconnected (overvoltage is protected) .

When the three-phase power supply is undervoltage: when the input terminal ② of the overvoltage micro-power voltage detection circuit of A1 is "0" potential, the output terminal ① is "0" potential, the a terminal of the XOR gate T1 is "0" potential, and T2 is not Gate input is "0" potential.

At the same time, the input terminal ② of the undervoltage micro-power consumption voltage detection circuit of A2 is "0" potential, the output terminal ① is "0" potential, the b terminal of the XOR gate T1 is "0" potential, and the input of the NOT gate of T2 is "0" potential. The non-gate output terminal outputs "1" potential JQ2 to work, and the JQ2 contact JQ2-1 connected in series to the JC1 and JC2 coils is switched from normally closed to normally open. At this time, the JC1 and JC2 coil circuits are disconnected (undervoltage protection) .

Because the JQ1 contact JQ1-1 in the phase sequence monitoring circuit is also connected in series with the JC1 and JC2 coils, when the phase sequence monitoring circuit detects that the network power supply is in the reverse phase sequence, the JC1 and JC2 AC contactors adjust the phase sequence first. Satisfy three conditions, 1. Overvoltage 2. No undervoltage 3. No phase loss. After the three conditions are met, the JQ2 and JQ3 contacts JQ2-2 and JQ3-1 connected in series in the JC1 and JC2 coils are in normal condition. In the closed state, that is to say, when one of the three conditions is lack of phase, BG1 cuts off, JQ3 pulls in, JQ3 normally closes and switches to normally open, JC1 or JQ2 relay coil circuit is disconnected, JC1 or JQ2 cannot work, three-phase AC There is no output voltage at the output terminal of the power supply. When the phase sequence changes under the condition of overvoltage, undervoltage and phase loss, the phase sequence monitoring and detection circuit will give a signal JQ1 to work, so that the coils connected in series JC1 and JC2 JQ1-1 switching, such as switching from JC1 to JC2 or switching from JC2 to JC1, so that the work of the whole set of devices is completed.

The technical effect of the utility model is that the three-phase AC power supply phase sequence automatic monitoring and control device is structurally composed of a phase sequence monitoring part, a lack of phase monitoring part, an overvoltage and undervoltage monitoring part, a three-phase power supply regulation output part and a working state display Therefore, it has complete functions and can not only display alarms for three-phase AC power supply overvoltage, undervoltage, phase loss, and phase loss faults, but also automatically adjust to ensure that the three-phase AC power supply always maintains a normal power supply state, thereby ensuring The electrical equipment with three-phase power supply works normally, and will not cause equipment burnout due to power supply voltage fluctuations, phase loss, or equipment shutdown due to incorrect power supply phase sequence and other reasons. The device is simple in structure and easy to use, and can be used in various electrical equipment using three-phase power supply.

Fig. 1 is the circuit schematic diagram of the utility model

Fig. 2 is a structural schematic diagram of the front panel of the utility model housing

Fig. 3 is a structural schematic diagram of the rear panel of the utility model casing

I phase sequence monitoring part, II lack of phase monitoring part, III overvoltage and undervoltage monitoring part, IV three-phase power regulation output part, V working status display part, ABC three-phase power input terminal, abc three-phase power output terminal, O terminal , R ₁ -R ₁₇ resistors, C ₁ -C ₈ capacitors, D ₁ rectifier diode, D ₂ D ₅ D ₆ D ₇ light-emitting diodes, D ₃ D ₄ rectifier bridge, JQ ₁ , JQ2, JQ ₃ relays, JC ₁ , JC ₂ relay, JQ _1-1 , JQ _1-2 , JQ _2-1 , JQ _2-2 , JQ _3-1 relay contact, JC _1-1 , JC _1-2 , JC _1-3 , JC _2-1 , JC _2-2 , relay contacts. A ₁ power monitoring integrated circuit, A ₂ current monitoring integrated circuit, A ₃ photoelectric coupling circuit, T ₁ exclusive OR gate, T ₂ NOT gate, B ₁ transformer, B ₂ three-phase series transformer, K ₁ phase sequence voltage selection switch, W ₁ W ₂ adjustable resistor, TR ₁ TR ₂ varistor.

The embodiment of the utility model is shown in the figure. The three-phase AC power supply phase sequence automatic monitoring and control device is a shell structure, which consists of a phase sequence monitoring part I, a phase loss monitoring part II, an overvoltage and undervoltage monitoring part III, and a three-phase The power control output part IV and the working state display part V are installed in the casing. The front panel of the casing displays the working state, and is equipped with light-emitting diodes D ₂ D ₅ D ₆ D ₇ phase sequence voltage selection switches and digital display voltage ammeters. The rear panel of the body is equipped with three-phase power input terminal ABC and three-phase power output terminal abc and O terminal.

Claims (1)

1, three-phase alternating-current supply phase sequence automatic monitoring regulation device is characterized in that being made of phase sequence monitoring part, phase shortage monitoring part, over-and under-voltage monitoring part, three phase mains regulation and control output, operating state display part; Phase sequence monitoring part is by piezo-resistance (TR ₁), (TR ₂), resistance (R ₇), (R ₈), (R ₉), (R ₁₀), electric capacity (C ₃), (C ₄), (C ₅), (C ₆), (C ₇), voltage-selected switch (K ₁), relay (JQ ₁) form 3 balancing circuitrys of phase sequence, the input of (A) in three-phase alternating current source, (B), (C) three-phase is (A) with resistance (R ₇), (R ₈) be in series (R ₉) and voltage-selected switch (K ₁) string is attempted by resistance (R ₈) on, (B) with electric capacity (C ₁), (C ₃), (C ₄), (C ₅), (C ₆) series connection, (C) phase and phase preface relay (JQ ₁) series connection, resistance (R ₁₀) and (C ₇) connecting is attempted by phase sequence relay (JQ ₁) two ends, the output of its (A), (B), (C) is connected to a bit (O), relay (JQ ₁) contact (JQ _1-1) is connected with three phase mains regulation and control output, between the line pressure, be connected to piezo-resistance (TR respectively between (B), (C) phase ₁), (TR ₂);

Phase shortage monitoring part is to be made of lack detection circuit, phase shortage power pushing circuit and power-supply circuit, and lack detection circuit is by resistance (R ₁), (R ₂), (R ₃), (R ₄), rectifier diode (D ₁), light-emitting diode (D ₂), electric capacity (C ₁) constitute, the input of three-phase alternating-current supply (A), (B), (C) respectively with (R ₁), (R ₂), (R ₃) series connection, its output in parallel and with rectifier diode (D ₁), resistance (R ₄) series connection, phase shortage indication light-emitting diode (D ₂) and electric capacity (C ₁) be connected in (O) point and rectifier diode (D ₂) output, the output of lack detection circuit and photoelectricity coupling circuit (A ₃) input 1,2 connect photoelectricity coupling circuit (A ₃) output 4,5 be connected with the phase shortage power pushing circuit, the phase shortage power pushing circuit is by resistance (R ₅), (R ₆), relay (JQ ₃), triode (GB ₁) constitute (R ₅), (R ₆) an end and (A ₃) 5 ends connect (R ₅) the other end and relay (JQ ₃) end connection, (JQ ₃) other end and (GB ₁) the emitter connection, (GB ₁) collector electrode and (A ₃) 4 ends connect (GB ₁) base stage and (R ₆) the other end connect rectified current routing transformer (B ₁), rectifier bridge (D ₃), three terminal regulator (A ₄), electric capacity (C ₂) constitute, 220V interchange being transformed into direct voltage is supplied with the work of phase shortage power pushing circuit, relay (JQ ₃) normally closed contact (JQ _2-1) be connected with three phase mains regulation and control output;

Over-and under-voltage monitoring part is made of sample circuit, overvoltage monitoring circuit, under-voltage monitoring circuit, and sample circuit is by three-phase concatenation type transformer (B ₂) and rectification circuit (D ₄) constitute three-phase concatenation type transformer (B ₂) coil (L _a), (L _b), (L _c) be coupled its output and rectifier bridge (D respectively with three phase mains (A), (B), (C) ₄) input connect the output of rectifier bridge and electric capacity (C ₈) and overvoltage adjustable resistance (W ₁), under-voltage adjustment resistance (W ₂) parallel connection, overvoltage monitoring circuit is by little power consumption voltage detecting circuit (A ₁) and overvoltage adjustable resistance (W ₁), resistance (R ₁₂) constitute (A ₁) 2. end and overvoltage adjustable resistance (W ₁) adjustable end connect (A ₁) output 1. with (R ₁₂) connect (R ₁₂) another termination XOR gate (T ₁) (B) end, (A ₁) 3. ground connection: under-voltage monitoring circuit is by little power consumption voltage detecting circuit (A ₂), adjustable resistance (W ₂), resistance (R1 ₄) form little power consumption voltage detecting circuit (A ₂) input 2. with under-voltage adjustable resistance (W ₂) adjustable end connect (A ₂) output 1. with resistance (R ₁₄) end connection, (R ₁₄) the other end and XOR gate (A) end is connected, electrical equipment (JQ is succeeded in the output NAND gate input connection of XOR gate between non-gate output terminal and the ground ₂), (JQ ₁) meet (JQ _2-1) be connected with three phase mains regulation and control output;

Three phase mains regulation and control output is by relay (JC ₁), (JC ₂), contact (JC _1-1), (JC _1-2), (JC _2-1), (JC _2-2), auxiliary contact (JC _1-3), (JC _2-3) and (JQ ₁) contact (JQ _1-1), (JQ ₂) contact (JQ _2-1), (JQ ₃) contact (JQ _3-1) form relay (JC ₂) and (JC _1-3), (JQ _1-1), (JQ _2-1) (JQ _3-1) series connection, two are terminated between the three-phase power output end line pressure (JC _1-1), (JC _2-1) in parallel be connected (JC with three-phase power input end (A) _1-2), (JC _2-2) in parallel be connected the other end (JC with three-phase power input end (B) _1-1), (JC _2-2) parallel connection is exported, (JC _1-2), (JC _2-1) output in parallel, be respectively three-phase power output end;

The operating state display part is by light-emitting diode (D ₅), (D ₆), (D ₇), resistance (K ₁₅), relay (JQ ₁) contact (JQ1 _-2), (JQ ₂) contact (JQ _2-2) form contact (JQ _1-2), (JQ _2-2) and light-emitting diode (D ₇) end connection ground connection, (JQ _1-2) the other end be connected (JQ with light-emitting diode (D5) _2-2) other end and light-emitting diode (D ₆) connect diode (D ₅), (D ₆) other end and connecting by resistance (R ₁₅) connect phase voltage.

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