CN104716735A - Control circuit of simple double-power-supply changeover device - Google Patents

Abstract

The invention discloses a control circuit of a simple dual power supply conversion device, which is characterized in that: when the normal power supply is normal, the power supply circuit of the backup power supply fails to work; the N phase of the normal power supply and the N phase of the backup power supply will not be connected at any time To avoid the unbalanced current flow caused by the two-way voltage collusion, which will cause the residual current circuit breaker at the front end to malfunction. The common power supply three-phase voltage loss detection circuit adopts the capacitor step-down circuit instead of the transformer. Among them, the common power supply A-phase voltage loss detection circuit doubles as the common power supply circuit, and uses the gate circuit and 555 timer integrated circuit as the logic control circuit instead of the microcontroller. . The invention mainly has the following advantages: the whole circuit structure is simple, scientific and ingenious, high reliability, good EMC performance, low power consumption; not only economical, cost-effective, easy to manufacture, convenient to maintain, low maintenance cost, energy saving and environmental protection, has Greater promotional value.

Description

A control circuit of a simple dual power conversion device

technical field

The invention relates to the field of dual-power conversion switching appliances, in particular to an electronic control circuit for dual-power conversion switching appliances.

Background technique

In some important occasions of low-voltage power distribution, in order to reduce economic losses caused by power outages, two power sources are used for power supply: common use, backup or mutual backup. Power the diesel generator. When one power supply fails to supply power normally due to a fault during the power supply process, the device whose load can be switched to another power supply is called a dual power supply switching device, or TSE for short. It is intended to be called a dual power conversion device, and its load is automatically switched to The other power supply device is called automatic transfer switching equipment, or ATSE for short.

At present, ATSE is generally composed of two parts: the automatic transfer switch body and the control circuit, and is mainly used in important places where power failure is not allowed. The automatic transfer switch body is mainly composed of two circuit breakers as main switches, a mechanical interlock mechanism to prevent the two circuit breakers, and a mechanical conversion mechanism driven by a bidirectional gear motor. The control circuit is mainly an intelligent control circuit with a microcontroller as the core. composition. When the control circuit detects that the common power supply voltage of the current power supply of the load exceeds the allowable deviation, ATSE will automatically switch to another backup power supply to ensure that the load power supply will not be interrupted for a long time; when the common power supply returns to normal, ATSE can automatically switch Return to the normal power supply for power supply, or continue to be powered by the current backup power supply, and then manually or remotely switch back to the normal power supply for power supply when appropriate.

ATSE with an intelligent control circuit is generally called an intelligent dual power conversion device. The rated working current of the main switch is generally above 100A for switching electrical appliances, and its price is relatively high. It is generally used in relatively large units, such as hospitals and airports. and other occasions. However, in some small-scale occasions, such as some small shopping malls, small companies and other places, the power consumption per unit time is relatively small, so only a small economical dual power conversion device with high cost performance can be used, such as the main switch. A small circuit breaker with a rated working current in the range of 16A~100A is enough, and the monitoring requirements for the power supply voltage are not large. Generally, it is only necessary to monitor the lack of phase and voltage failure of common power supplies.

The control circuit of the intelligent dual power conversion device is complex and the manufacturing cost is high. For example, there are at least two power supplies in the control circuit to provide working power for the entire circuit. After stepping down the normal power supply and the backup power supply through two power transformers, they are rectified and then connected in parallel. This requires two power supplies to supply power at the same time, resulting in waste. The circuit that monitors the voltage of the two power supplies generally uses a small transformer as a step-down device to reduce the power frequency voltage proportionally to a relatively low safe voltage and input it to the voltage detection terminal of the control circuit for voltage monitoring. Generally, two-way three-phase voltage detection requires 6 small transformers. Small transformers are inductive loads. Because of their large size, they occupy a large space in the controller, which is not conducive to the miniaturization of the controller; and there are also small transformers with high harmonics, High radiation, high cost, high power consumption, easy to burn out and other defects. Another example is the microcontroller. In the electric room environment with harsh working conditions, the electromagnetic interference is serious, easy to damage, easy to malfunction, relatively poor in reliability, and requires programming, which is difficult to develop and maintain.

Contents of the invention

In order to solve the above defects in the control circuit of the existing simple dual power conversion device, the present invention provides a control circuit of the simple dual power conversion device with simple and scientific structure, low power consumption, low cost and high reliability.

In order to achieve the above object, the solution adopted by the present invention is: a control circuit of a simple dual power conversion device, which includes a conversion motor and a travel switch arranged in the mechanical conversion mechanism of the dual power conversion device, and is characterized in that: it also Including three-phase voltage loss detection circuit of common power supply, signal shaping circuit, conversion motor control circuit, delay circuit for common power transfer to standby, power supply circuit of common power supply for the aforementioned four circuits, delay circuit for standby transfer to common use, and delay circuit for standby transfer A standby power supply circuit for supplying power to the commonly used delay circuit; wherein, the commonly used switch to the standby delay circuit and the standby switch to the commonly used delay circuit are at least provided with a set of controllable switches with normally open contacts and normally closed contacts, and the conversion motor The control circuit is provided with at least two groups of controllable switches with normally open contacts and normally closed contacts; the power supply circuit of the common power supply is connected to the phase A of the common power supply, and the output terminal of the three-phase voltage loss detection circuit of the common power supply is connected to the signal shaping circuit The input end of the switch is connected, and the input end of the common transfer delay circuit and the control input end of the conversion motor control circuit are connected with the output end of the signal shaping circuit; the first common end of the controllable switch of the conversion motor control circuit passes through a travel switch The normally closed contact of the switch is connected to the common power supply A, and the second common terminal of the controllable switch of the conversion motor control circuit is connected to the A phase of the standby power supply through the normally closed contact of a travel switch. Correspondingly, the first common terminal corresponds to The first normally open contact is connected to the forward rotation control terminal of the conversion motor, the second normally closed contact corresponding to the second common terminal is connected to the reverse rotation control terminal of the conversion motor, and the input terminal of the backup power supply circuit is connected to the second normally closed contact The normally open contact of the commonly used transfer to the backup delay circuit is connected to the N phase of the common power supply, the normally open contact of the backup transfer to the backup delay circuit is connected to the N phase of the backup power supply, and the normally open contact is transferred to the backup delay circuit The public end of the spare is connected to the common end of the switching motor; the common end of the spare to the common delay circuit is connected to the common end of the switching motor, or the common The closed contact is connected. Among them, what needs to be specially explained is that the common terminal of the backup transfer to the normal delay circuit is connected to the normally closed contact of the backup transfer to the normal delay circuit to ensure that the N phase of the normal power supply and the N phase of the backup power supply will not be connected to the N phase at the same time. Switch the common terminal of the motor to avoid the unbalanced current flow caused by the collusion of the two voltages, which will cause the residual current circuit breaker at the front end to malfunction.

As a further explanation of the above scheme, when the common power supply loses phase and loses voltage, the three-phase voltage loss detection circuit of the common power supply sends out an abnormal signal, which is sent to the conversion motor control circuit after being shaped by the signal shaping circuit. circuit, the conversion motor control circuit and the controllable switch action of the common transfer to the standby delay circuit, all the normally open contacts of the controllable switch are disconnected, and the electrical connection between the conversion motor and the common power supply is in a disconnected state; the backup power supply circuit and The conversion motors are all connected to the A-phase circuit of the standby power supply, and start to supply power for the standby power supply to the common delay circuit. First, the conversion motor is connected to the N-phase circuit of the backup power supply, and the conversion motor is powered by the A-phase circuit of the backup power supply. After the circuit breaker on the power supply side is in the closed state, the normally closed contact of the travel switch connected to phase A of the backup power supply is disconnected, the conversion motor stops when it loses power, and the load is powered by the backup power supply. When the common power supply returns to normal, the three-phase voltage loss detection circuit of the common power supply sends out a normal signal, which is sent to the conversion motor control circuit, the normal transfer to the standby delay circuit, and the conversion motor control circuit and the common transfer to the backup after being processed by the signal shaping circuit The controllable switches of the delay circuit act sequentially, the conversion motor is disconnected from the A phase and the N phase of the backup power supply, and at the same time, the backup power supply circuit is also disconnected from the A phase of the backup power supply, and the transfer to the normal delay circuit is stopped. Power supply, all the normally open contacts of the control circuit of the conversion motor and the controllable switch that are normally transferred to the standby delay circuit are connected, and the electrical connection between the conversion motor and the common power supply is in the connected state; When the breaker is disconnected, close the circuit breaker on the common power supply side. After the circuit breaker on the common power supply side is in the closed state, the normally closed contact of the travel switch connected to phase A of the common power supply is disconnected, and the conversion motor stops when it loses power. , the load is powered by the normal power supply. Therefore, when the common power supply is normally powered, only the common power supply circuit provides working power in the whole circuit, while the backup power supply circuit is in a power-off state, ensuring that the two power supplies do not interfere with each other, increasing the independence of the normal power supply and the backup power supply, and reducing The working time of related electronic devices not only saves electric energy, improves the reliability of the system, but also improves the service life of electronic devices.

The aforementioned common power supply three-phase loss-of-voltage detection circuit includes a common power supply A-phase loss-of-voltage detection circuit, a common power supply B-phase loss-of-voltage detection circuit, and a common power supply C-phase loss-of-voltage detection circuit whose input terminals are respectively connected to the three phases of the common power supply. ; Among them, the A-phase loss-of-voltage detection circuit of the common power supply is also used as the power supply circuit of the common power supply. The circuit includes a B-phase capacitor step-down circuit, a B-phase rectification and voltage stabilization circuit, and a B-phase photoelectric isolation circuit in series; a common power supply C-phase voltage loss detection circuit includes a C-phase capacitor step-down circuit in series, a C-phase rectification and voltage stabilization circuit. circuit, and the C-phase photoelectric isolation circuit; wherein, the A-phase rectification and voltage stabilization circuit, the B-phase photoelectric isolation circuit, the C-phase photoelectric isolation circuit, and the aforementioned signal shaping circuit are connected in series successively. Since the A-phase rectification and voltage stabilization circuit, the B-phase photoelectric isolation circuit, the C-phase photoelectric isolation circuit, and the aforementioned signal shaping circuit are connected in series successively, as long as one phase of the common power supply loses voltage, the signal shaping circuit will not get a normal signal. And send an abnormal signal. Common power A-phase loss of voltage detection circuit cleverly doubles as a common power supply circuit. When A-phase loses voltage, B-phase photoelectric isolation circuit and C-phase photoelectric isolation circuit cannot receive working power and cannot send signals, saving a common The A-phase photoelectric isolation circuit of the A-phase of the power supply reduces the size of the entire control circuit, saves electronic components, and reduces costs. Using a capacitor step-down circuit as a voltage circuit, since the capacitor is a reactive device, it does not consume active power and does not generate heat during operation. Compared with the transformer, it is safer, smaller in size, less in pins, easy to install, and saves more space for the controller. , the cost is also lower, which is conducive to energy saving and environmental protection.

Preferably, the aforementioned A-phase capacitive step-down circuit, B-phase capacitive step-down circuit and C-phase capacitive step-down circuit all include a non-polar capacitor that can withstand power frequency high voltage and a discharge resistor connected in parallel with the non-polar capacitor; the capacitive drop The input terminal of the piezo circuit module is parallel connected with a piezoresistor.

More specifically, the aforementioned non-polar capacitor is a CBB capacitor or a safety capacitor with a withstand voltage of 240V-1000V.

The use of capacitor step-down circuit, because the capacitor is a capacitive load, its EMC performance is good, in theory it does not consume power, the power consumption becomes very low, and the harmonics are small. CBB capacitors or safety capacitors are cheap and have high safety performance.

The principle of the capacitive step-down circuit is actually to use the capacitive reactance to limit the current, and the current calculation formula is explained below. For example, when the AC voltage of 220V/50Hz is used as the control voltage and the capacitance C is 1uF, the current (average value) obtained by full-wave rectification is: I(AV)=0.89×V/Zc=0.89× 220×2×∏×f×C =0.89×220×2×3.14×50×C=60000C =60000×0.000001=0.06A=60mA. If the capacity of the non-polar capacitor is reasonably selected, the circuit can work normally.

Preferably, the aforementioned A-phase rectifying and stabilizing circuit, B-phase rectifying and stabilizing circuit, C-phase rectifying and stabilizing circuit and the backup power supply circuit all include an integrated full-wave rectifying bridge and a filter capacitor arranged at the output end of the full-wave rectifying bridge, The output end of the full-wave rectifier bridge is provided with a voltage stabilizing circuit composed of a voltage stabilizing resistor and a voltage stabilizing diode connected in series. Among them, the voltage stabilizing diode in the phase A rectifying voltage stabilizing circuit and the standby power supply circuit is a voltage stabilizing diode with a voltage stabilizing value of 12V. The voltage regulator diodes in the B-phase rectification and voltage stabilization circuit and the C-phase rectification and voltage stabilization circuit are voltage stabilization diodes with a voltage stabilization value of 5V; the output terminal of the A-phase rectification and voltage stabilization circuit is connected with a voltage stabilization integrated circuit with a voltage stabilization value of 5V and a filter The secondary voltage stabilizing circuit composed of capacitors, the secondary voltage stabilizing circuit provides working power for the common power supply three-phase voltage loss detection circuit, signal shaping circuit, conversion motor control circuit, common to standby delay circuit; B-phase photoelectric isolation circuit Phase C and phase C photoelectric isolation circuits are composed of a photocoupler, the two photocouplers are integrated two optocoupler type PC521-2 dual optocoupler integrated circuit, and their input terminals are respectively connected to phase B The rectifying voltage stabilizing circuit is connected with the output end of the voltage stabilizing diode in the C-phase rectifying voltage stabilizing circuit, the C pole of the first unit photocoupler is connected with the output end of the 5V voltage stabilizing integrated circuit through a pull-up resistor, and the first unit photoelectric coupling The e pole of the device is connected to the c pole of the second unit photocoupler, and the e pole of the second unit photocoupler is connected to the input terminal of the signal shaping circuit.

The aforementioned signal shaping circuit is mainly composed of two stages of NAND gate circuits with Schmitt triggers connected in series. The input terminals of each NAND gate circuit are connected together. A pull-down resistor and a capacitor to ground are connected in parallel. The NAND gate circuit of the Schmitt trigger has a voltage fluctuation window, which can effectively prevent the short-term fluctuation of the common power supply voltage from causing frequent switching of the conversion motor and affecting the power supply to the load.

The controllable switch in the aforementioned conversion motor control circuit is a power selection relay with two sets of normally closed and normally open switch contacts, the common end of the first set of switch contacts and the common end of the second set of switch contacts respectively correspond to Convert the first common terminal and the second common terminal of the controllable switch of the motor control circuit; correspondingly, the normally open contacts of the first group of switch contacts and the normally closed contacts of the second group of switch contacts correspond to the first One normally open contact and the second normally closed contact, the power selection relay is driven by an NPN type power selection transistor, and the b pole of the power selection transistor is connected to the second stage NAND gate circuit output terminal of the signal shaping circuit through a resistor; The input end of the standby power supply circuit is connected with the normally closed contacts of the second group of switch contacts.

The aforementioned commonly used transfer delay circuit includes a common charging and discharging circuit composed of a potentiometer and a capacitor connected in series, a logic circuit composed of two connected NAND circuits with Schmitt triggers connected in series, and a logic circuit with a set of normally open contacts. Commonly used N-phase control relays with contacts and normally closed contacts; among them, the input terminals of each NAND gate circuit are connected together, and the potentiometer input terminal in the common charging and discharging circuit is connected with the b pole of the power selection transistor. The power supply is connected to the ground wire, and the output terminal of the potentiometer in the commonly used charging and discharging circuit is connected to the input terminal of the input terminal of the first-stage NAND gate circuit; the commonly used N-phase control relay is driven by an NPN type commonly used N-phase control transistor, and the commonly used N-phase The b-pole of the control triode is connected to the output terminal of the second-level NAND gate circuit of the logic circuit through a resistor; the normally open contact of the commonly used N-phase control relay corresponds to the normally open contact previously referred to as the standby delay circuit, commonly used The common end of the N-phase control relay corresponds to the common end of the common transfer to the backup delay circuit.

The aforesaid backup transfer to common delay circuit includes a backup charge and discharge circuit composed of fixed resistors, potentiometers and capacitors in series, a logic drive circuit composed of 555 timer integrated circuits, and a set of normally open and normally closed contactors. The backup N-phase control relay of the head; among them, the pin 2 and pin 6 of the 555 timer integrated circuit are connected together and then connected to the output terminal of the potentiometer in the backup charge and discharge circuit, and the fixed resistor input in the backup charge and discharge circuit The terminal is connected to the positive output terminal of the full-wave rectifier bridge in the backup power supply circuit, and the pin 1 of the 555 timer integrated circuit is connected to the negative terminal of the full-wave rectifier bridge in the backup power supply circuit. , pin 4 and pin 8 of the 555 timer integrated circuit are connected to the positive output terminal of the full-wave rectifier bridge in the backup power supply circuit; the backup N-phase control relay is driven by a pin 3 of the 555 timer integrated circuit That is, one end of the coil of the standby N-phase control relay is connected to the positive output terminal of the full-wave rectifier bridge in the standby power supply circuit, and the other end is connected to pin 3 of the 555 timer integrated circuit; the normally open contact of the standby N-phase control relay The head corresponds to the aforementioned normally open contact of the standby forwarding to the commonly used delay circuit, and the common end of the standby N-phase control relay corresponds to the common end of the standby forwarding to the commonly used delay circuit delay circuit.

The aforementioned control circuit also includes a state indicating circuit indicating whether the circuit breaker as the main switch is in the closing state, and the state indicating circuit is connected with the travel switch.

It can be seen from the above that the present invention mainly has the following advantages: the whole circuit structure is simple, scientific and ingenious, high reliability, good EMC performance, low power consumption; not only good economy, high cost performance, easy manufacture, convenient maintenance, low maintenance cost, Energy saving and environmental protection, has great promotion value.

Description of drawings

Fig. 1 is the block diagram of circuit principle of the present invention.

Figure 2 is a schematic block diagram of a common power supply three-phase voltage loss detection circuit.

FIG. 3 is a schematic diagram of the circuit in FIG. 2 .

Fig. 4 is a circuit schematic diagram of the main control circuit part of the present invention.

Fig. 5 is a circuit schematic diagram of the state indication circuit.

Explanation of the main figures: 11—conversion motor 12—travel switch 13—three-phase voltage loss detection circuit for common power supply 131—phase A voltage loss detection circuit 1311—phase A capacitor step-down circuit 1312—phase A rectification and voltage stabilization circuit 132— Common power supply B-phase voltage loss detection circuit 1321—B-phase capacitor step-down circuit 1322—B-phase rectification and voltage stabilization circuit 1323—B-phase photoelectric isolation circuit 133—C-phase power loss detection circuit of common power supply 1331—C-phase capacitor step-down circuit 1332 —C-phase rectification and voltage stabilization circuit 1333—C-phase photoelectric isolation circuit 14—signal shaping circuit 15—conversion motor control circuit 16—commonly transferred to standby delay circuit 17—commonly used power supply circuit 18—standby transferred to commonly used delay circuit 19 —Standby power supply circuit 20—Status indication circuit.

Detailed ways

The present invention and its beneficial technical effects will be further described in detail below in conjunction with the accompanying drawings and preferred embodiments.

Referring to Figures 1 to 5, the control circuit of the simple dual power conversion device includes a conversion motor 11 and a travel switch 12 located in the mechanical conversion mechanism of the dual power conversion device, a common power supply three-phase loss of voltage detection circuit 13, and a signal shaping circuit 14, conversion motor control circuit 15, commonly used forward to standby time delay circuit 16, for the common power supply circuit 17 of four circuit power supply, standby forwards to commonly used time delay circuit 18, for standby forwards to the standby of commonly used time delay circuit 18 power supply Power supply circuit 19; Wherein, commonly used and forward to standby time delay circuit 16, standby time delay circuit 18 is provided with at least one group of controllable switches with normally open contacts and normally closed contacts, and the conversion motor control circuit 15 is at least set There are two groups of controllable switches with normally open contacts and normally closed contacts; the common power supply circuit 17 is connected to the A phase of the common power supply, and the output terminal of the common power supply three-phase voltage loss detection circuit 13 is connected to the signal shaping circuit 14 The input end is connected, and the input end of the standby delay circuit 16 is commonly used and the control input end of the conversion motor control circuit 15 is connected with the output end of the signal shaping circuit 14; the first common end of the controllable switch of the conversion motor control circuit 15 passes through The normally closed contact of a travel switch 12 is connected to the common power supply A, and the second common end of the controllable switch of the conversion motor control circuit 15 is connected to the A of the backup power supply through the normally closed contact of a travel switch 12, correspondingly , the first normally open contact corresponding to the first common terminal is connected to the forward rotation control terminal of the conversion motor 11, the second normally closed contact corresponding to the second common terminal is connected to the reverse rotation control terminal of the conversion motor 11, and the backup power supply circuit 19 The input terminal is connected with the second normally closed contact; the normally open contact of the standby delay circuit 16 is usually connected with the N phase of the common power supply, and the normally open contact of the standby delay circuit is connected with the N of the standby power supply. be connected to each other, and the common end of the standby time delay circuit 16 is commonly used to be connected with the common end of the conversion motor 11; The common end of the circuit 18 is connected with the normally closed contact of the standby time delay circuit 18 for normal use.

Referring to Fig. 2 and Fig. 3, the common power supply three-phase loss-of-voltage detection circuit 13 includes a common power supply A-phase loss-of-voltage detection circuit 131, a common power supply B-phase loss-of-voltage detection circuit 132, And the common power supply C-phase loss of voltage detection circuit 133; wherein, the common power supply A-phase loss of voltage detection circuit 131 doubles as the common power supply power supply circuit 17, and the common power supply A-phase loss of voltage detection circuit 131 includes A-phase capacitor step-down circuit 1311, A-phase rectification and voltage stabilization circuit 1312; common power supply B-phase voltage loss detection circuit 132 includes B-phase capacitor step-down circuit 1321, B-phase rectification and voltage stabilization circuit 1322, and B-phase photoelectric isolation circuit 1323; The voltage detection circuit 133 includes a C-phase capacitor step-down circuit 1331, a C-phase rectification and voltage stabilization circuit 1332, and a C-phase photoelectric isolation circuit 1333 connected in series; wherein, the A-phase rectification and stabilization circuit 1312, the B-phase photoelectric isolation circuit 1323, The phase photoelectric isolation circuit 1333 and the signal shaping circuit 14 are sequentially connected in series.

Referring to Fig. 3, the A-phase capacitance step-down circuit 1311, the B-phase capacitance step-down circuit 1321 and the C-phase capacitance step-down circuit 1331 all include nonpolar capacitors (C1, C2, C3) that can withstand power frequency high voltage and are connected to the nonpolar capacitors. It is composed of discharge resistors (R6, R8, R10) connected in parallel with neutral capacitors (C1, C2, C3); the input terminal of the capacitor step-down circuit module is connected with piezoresistors (Rt1, Rt2, Rt3) in parallel.

Non-polar capacitors (C1, C2, C3) are CBB capacitors or safety capacitors with a withstand voltage of 240V~1000V. The capacity of non-polar capacitors (C1, C2, C3) is preferably 0.1uF~2.2uF. Matching ground, the discharge resistors (R6, R8, R10) are 330kΩ~1000kΩ.

Referring to Fig. 3, the A-phase rectifying and stabilizing circuit 1312, the B-phase rectifying and stabilizing circuit 1322, the C-phase rectifying and stabilizing circuit 1332 and the backup power supply circuit 19 all include integrated full-wave rectifying bridges (D8, D9, D10, D11) , and the filter capacitors (C8, C9, C10, C12) located at the output ends of the full-wave rectifier bridges (D8, D9, D10, D11), and the output ends of the full-wave rectifier bridges (D8, D9, D10, D11) are provided with voltage regulators A voltage stabilizing circuit composed of resistors (R5, R7, R9) and voltage stabilizing diodes (VD1, VD3, VD4, VD2) connected in series, wherein, the phase A rectification voltage stabilizing circuit 1312 and the voltage stabilizing diode (VD1 , VD2) are voltage stabilizing diodes with a voltage stabilization value of 12V, and the voltage stabilization diodes VD3 and VD4) in the B-phase rectification and voltage stabilization circuit and the C-phase rectification and voltage stabilization circuit 1332 are voltage stabilization diodes with a voltage stabilization value of 5V; The output terminal of voltage circuit 1312 is connected with a secondary voltage stabilization circuit composed of 5V voltage stabilization integrated circuit U1 and filter capacitors (C11, C4). The secondary voltage stabilization circuit is a common power supply three-phase voltage loss detection circuit 13 , signal shaping circuit 14, conversion motor control circuit 15, common transfer to standby delay circuit 16 to provide operating power; B-phase photoelectric isolation circuit 1323 and C-phase photoelectric isolation circuit 1333 are each made up of an optocoupler, the two The optocoupler is a PC521-2 dual optocoupler integrated circuit U2 that integrates two optocouplers. The output terminals of VD3 and VD4) are connected, the c pole of the photocoupler of the first unit is connected with the output terminal of the 5V voltage stabilizing integrated circuit U1 through the pull-up resistor R12, and the pole e of the photocoupler of the first unit is photocoupled with the second unit The c pole of the device is connected, and the e pole of the second unit photocoupler is connected with the input terminal of the signal shaping circuit 14 .

Referring to Fig. 3, the signal shaping circuit 14 is mainly composed of two stages of NAND gate circuits (U31, U41) with Schmitt triggers connected in series, the input ends of each NAND gate circuit are connected together, and the first stage NAND gate circuit A pull-down resistor R11 and a grounding capacitor C7 are connected in parallel between the input terminal of U31 and the common power supply grounding line. The controllable switch in the conversion motor control circuit 15 is a power selection relay KA1 with two sets of normally closed and normally open switch contacts, the common ends of the first set of switch contacts and the common ends of the second set of switch contacts respectively correspond to The first common terminal and the second common terminal of the controllable switch of the conversion motor control circuit 15; correspondingly, the normally open contacts of the first group of switch contacts and the normally closed contacts of the second group of switch contacts respectively For the first normally open contact and the second normally closed contact, the power selection relay KA1 is driven by an NPN type power selection transistor Q1, and the b pole of the power selection transistor Q1 is connected to the second stage of the signal shaping circuit 14 through a resistor R14 The output end of the NAND gate circuit U41; the input end of the standby power supply circuit 19 is connected with the normally closed contacts of the second group of switch contacts. The preferred model of the NAND gate circuit with Schmitt trigger is CD4093 integrated circuit, which integrates 4 units of NAND gate circuit units inside, just enough to meet the quantity of the above four NAND gate circuits.

Referring to Fig. 4, the normal-to-standby delay circuit 16 includes a common charge-discharge circuit composed of a potentiometer PR1 and a capacitor C13 connected in series, consisting of two series-connected NAND circuits (U51, U61) with Schmitt triggers logic circuit, and a commonly used N-phase control relay KA3 with a set of normally open contacts and normally closed contacts; among them, the input terminals of each NAND gate circuit are connected together, and the input terminal of the potentiometer PR1 in the commonly used charge and discharge circuit It is connected to the b pole of the power selection transistor Q1, the capacitor C13 is connected to the ground wire of the common power supply, and the output terminal of the potential PR1 device in the common charging and discharging circuit is connected to the input terminal of the input terminal of the first-stage NAND gate circuit U51; the common N-phase control The relay KA3 is driven by an NPN type commonly used N-phase control transistor Q2, and the b pole of the commonly used N-phase control transistor Q2 is connected to the output terminal of the second-stage NAND gate circuit U61 of the logic circuit through a resistor R15; the commonly used N-phase control relay KA3 The normally open contact of the N-phase control relay KA3 corresponds to the common end of the commonly used transfer to the backup delay circuit 16.

Referring to Fig. 4, the standby transfer to the common delay circuit 18 includes a standby charging and discharging circuit composed of a fixed resistor R16, a potentiometer PR2 and a capacitor C14 connected in series in sequence, a logic drive circuit composed of a 555 timer integrated circuit U7, and a circuit with There is a spare N-phase control relay KA2 with a set of normally open and normally closed contacts; among them, pin 2 and pin 6 of the 555 timer integrated circuit U7 are connected together and then connected to the output terminal of the potentiometer PR2 in the spare charge and discharge circuit , the input terminal of the fixed resistor in the standby charging and discharging circuit is connected with the positive output terminal of the full-wave rectifier bridge D11 in the standby power supply circuit 19, the pin 1 of the 555 timer integrated circuit U7 and the capacitor C14 in the standby charging and discharging circuit One end is connected to the negative pole of the full-wave rectifier bridge D11 in the backup power supply circuit 19, and the pin 4 and pin 8 of the 555 timer integrated circuit U7 are connected to the positive output end of the full-wave rectifier bridge D11 in the backup power supply circuit 19 Connected; the standby N-phase control relay KA2 is driven by a pin 3 of the 555 timer integrated circuit U7, that is, one end of the coil of the standby N-phase control relay KA2 is connected to the positive output terminal of the full-wave rectifier bridge D11 in the standby power supply circuit 19 connected, and the other end is connected to pin 3 of the 555 timer integrated circuit U7; the normally open contact of the spare N-phase control relay KA2 corresponds to the normally open contact of the spare transfer to the common delay circuit 18, and the spare N-phase control relay KA2 The common end corresponding to the backup is transferred to the common end of the common delay circuit 18 delay circuit.

Referring to FIG. 5 , the control circuit further includes a state indicating circuit 12 which indicates whether the circuit breaker as the main switch is in the closing state, and the state indicating circuit 12 is connected with the travel switch 12 .

The above specification and specific examples do not constitute any limitation to the present invention. The present invention is not limited to the specific implementation methods disclosed and described above. Some modifications and variations of the present invention should also fall within the protection scope of the claims of the present invention. Inside.

Claims (10)

1. A control circuit of a simple dual-power conversion device, which includes a conversion motor and a travel switch located in the mechanical conversion mechanism of the dual-power conversion device, and is characterized in that: it also includes a common power supply three-phase loss of voltage detection circuit, Signal shaping circuit, conversion motor control circuit, common power supply circuit for backup delay circuit, common power supply circuit for the aforementioned four circuits, backup power supply for common delay circuit, backup power supply for backup power supply for common delay circuit circuit; among them, at least one set of controllable switches with normally open contacts and normally closed contacts is provided at least one set of controllable switches with normally open contacts and normally closed contacts at least one set of controllable switches with normally open The controllable switch of the contact and the normally closed contact; the common power supply circuit is connected to the A phase of the common power supply, the output terminal of the three-phase voltage loss detection circuit of the common power supply is connected to the input terminal of the signal shaping circuit, and the common power supply is transferred to the spare delay The input end of the timing circuit and the control input end of the conversion motor control circuit are connected to the output end of the signal shaping circuit; the first common end of the controllable switch of the conversion motor control circuit is connected to the common power supply A phase through a normally closed contact of a travel switch connected, the second common end of the controllable switch of the conversion motor control circuit is connected to the A phase of the standby power supply through a normally closed contact of a travel switch, and correspondingly, the first normally open contact corresponding to the first common end is connected to the conversion motor The forward rotation control terminal is connected, the second normally closed contact corresponding to the second common terminal is connected to the reverse control terminal of the conversion motor, and the input terminal of the backup power supply circuit is connected to the second normally closed contact; The normally open contact of the normal power supply is connected to the N phase of the common power supply, the normally open contact of the spare to the standby delay circuit is connected to the N phase of the standby power supply, and the common terminal of the common to the standby delay circuit is connected to the common terminal of the conversion motor ; The common end of the standby transfer to the common delay circuit is connected to the common end of the conversion motor, or the common end of the backup transfer to the common delay circuit is connected to the normally closed contact of the backup transfer to the common delay circuit. 2. The control circuit of the simple dual-power conversion device as claimed in claim 1, wherein the three-phase loss-of-voltage detection circuit of the common power supply includes a common power supply A whose input terminals are respectively connected to the corresponding three-phase common power supplies Phase loss detection circuit, common power supply B-phase loss detection circuit, and common power supply C-phase loss detection circuit; wherein, the common power supply A-phase loss-of-voltage detection circuit doubles as a common power supply circuit, and the common power supply A-phase loss detection circuit includes The A-phase capacitor step-down circuit and the A-phase rectifier and voltage regulator circuit are connected in series; the common power supply B-phase voltage loss detection circuit includes the B-phase capacitor step-down circuit, the B-phase rectifier and voltage regulator circuit, and the B-phase photoelectric isolation circuit connected in series; Commonly used power supply C-phase voltage loss detection circuit includes C-phase capacitor step-down circuit, C-phase rectification and voltage stabilization circuit, and C-phase photoelectric isolation circuit; among them, A-phase rectification and stabilization circuit, B-phase photoelectric isolation circuit, C-phase The photoelectric isolation circuit and the aforementioned signal shaping circuit are serially connected in sequence. 3. The control circuit of the simple dual-power conversion device as claimed in claim 2, characterized in that: the A-phase capacitor step-down circuit, the B-phase capacitor step-down circuit and the C-phase capacitor step-down circuit all include a Krona It is composed of a non-polar capacitor with power frequency and high voltage and a discharge resistor connected in parallel with the non-polar capacitor; the input terminal of the capacitor step-down circuit module is connected with a varistor in parallel. 4 . The control circuit of a simple dual power conversion device according to claim 2 , wherein the non-polar capacitor is a CBB capacitor or a safety capacitor with a withstand voltage of 240V-1000V. 5. The control circuit of the simple dual-power conversion device as claimed in claim 4, characterized in that: the A-phase rectification and stabilization circuit, the B-phase rectification and stabilization circuit, the C-phase rectification and stabilization circuit and the backup power supply circuit Both include an integrated full-wave rectifier bridge and a filter capacitor set at the output end of the full-wave rectifier bridge. The output end of the full-wave rectifier bridge is equipped with a voltage stabilizing circuit composed of a voltage stabilizing resistor and a voltage stabilizing diode in series. Among them, the phase A rectifier voltage stabilizing The zener diodes in the circuit and the standby power supply circuit are 12V zener diodes, and the zener diodes in the B-phase rectifier and stabilizer circuit and the C-phase rectifier and stabilizer circuit are 5V zener diodes; A The output end of the phase rectification and voltage stabilization circuit is connected with a secondary voltage stabilization circuit composed of a voltage stabilization integrated circuit of 5V and a filter capacitor. The secondary voltage stabilization circuit is a common power supply three-phase voltage loss detection circuit, a signal shaping circuit, The conversion motor control circuit and the common to standby delay circuit provide working power; the B-phase photoelectric isolation circuit and the C-phase photoelectric isolation circuit are each composed of a photocoupler, and the two photocouplers are integrated with two photocouplers. The type of the device is PC521-2 dual optocoupler integrated circuit, its input terminals are respectively connected to the output terminals of the voltage regulator diodes in the B-phase rectification and stabilization circuit and the C-phase rectification and stabilization circuit, and the c of the first unit photocoupler The pole is connected to the output terminal of the 5V voltage stabilizing integrated circuit through a pull-up resistor, the e pole of the first unit photocoupler is connected to the c pole of the second unit photocoupler, and the e pole of the second unit photocoupler is connected to the signal shaping circuit input connection. 6. The control circuit of the simple dual-power conversion device as claimed in claim 5, characterized in that: the signal shaping circuit is mainly composed of two stages of NAND circuits with Schmitt triggers connected in series, each NAND The input terminals of the gate circuit are connected together, and a pull-down resistor and a ground capacitance are connected in parallel between the input terminal of the first-stage NAND gate circuit and the common power supply ground wire. 7. The control circuit of the simple dual power conversion device as claimed in claim 6, characterized in that: the controllable switch in the conversion motor control circuit is a power selection relay provided with two sets of normally closed and normally open switch contacts , the common end of the first set of switch contacts and the common end of the second set of switch contacts respectively correspond to the first common end and the second common end of the controllable switch of the conversion motor control circuit; correspondingly, the first set The normally open contact of the switch contact and the normally closed contact of the second group of switch contacts correspond to the first normally open contact and the second normally closed contact respectively. The power selection relay is driven by an NPN type power selection transistor. The b-pole of the power selection transistor is connected to the output terminal of the second-stage NAND gate circuit of the signal shaping circuit through a resistor; the input terminal of the backup power supply circuit is connected to the normally closed contacts of the second group of switch contacts. 8. The control circuit of a simple dual-power conversion device as claimed in claim 7, wherein: said common transfer to standby delay circuit includes a common charging and discharging circuit composed of a potentiometer and a capacitor connected in series, which is composed of two series connected A logic circuit composed of a NAND gate circuit with a Schmitt trigger, and a common N-phase control relay with a set of normally open contacts and normally closed contacts; wherein, the input terminals of each NAND gate circuit are connected together The input terminal of the potentiometer in the commonly used charge and discharge circuit is connected to the b pole of the power selection transistor, and the capacitor is connected to the ground wire of the common power supply. The input terminal is connected; the common N-phase control relay is driven by an NPN type common N-phase control transistor, and the b pole of the common N-phase control transistor is connected to the output terminal of the second-level NAND circuit of the logic circuit through a resistor; the common N-phase The normally open contact of the control relay corresponds to the normally open contact described in the commonly used transfer to the standby delay circuit, and the common terminal of the commonly used N-phase control relay corresponds to the common terminal of the commonly used transfer to the standby delay circuit. 9. The control circuit of a simple dual-power conversion device as claimed in claim 3, characterized in that: said backup transfer to normal delay circuit includes a backup charging and discharging circuit consisting of fixed resistors, potentiometers and capacitors connected in series. circuit, a logic drive circuit composed of a 555 timer integrated circuit, and a spare N-phase control relay with a set of normally open and normally closed contacts; where pin 2 and pin 6 of the 555 timer integrated circuit are connected together Connect with the output terminal of the potentiometer in the backup charging and discharging circuit, connect the input terminal of the fixed resistor in the backup charging and discharging circuit with the positive output terminal of the full-wave rectifier bridge in the backup power supply circuit, and connect the pin of the 555 timer integrated circuit 1 and one end of the capacitor in the backup charging and discharging circuit is connected to the negative pole of the full-wave rectifier bridge in the backup power supply circuit, and the pin 4 and pin 8 of the 555 timer integrated circuit are connected to the full-wave rectifier bridge in the backup power supply circuit The positive output terminals are connected together; the standby N-phase control relay is driven by pin 3 of the 555 timer integrated circuit, that is, one end of the coil of the standby N-phase control relay is connected to the positive output terminal of the full-wave rectifier bridge in the standby power supply circuit , the other end is connected to pin 3 of the 555 timer integrated circuit; the normally open contact of the spare N-phase control relay corresponds to the normally open contact described in the spare transfer to the common delay circuit, and the common terminal of the spare N-phase control relay Corresponding to the common end of the delay circuit for the standby transfer to the common delay circuit. 10. The simple dual power supply according to claim 9, characterized in that: said control circuit also includes a state indicating circuit indicating whether the circuit breaker as the main switch is in the closed state, the state indicating circuit and the travel switch connected.