Dual-power-supply automatic conversion control circuit and dual-power-supply automatic conversion switch

Abstract

The utility model discloses a dual-power-supply automatic conversion control circuit and a dual-power-supply automatic conversion switch. The dual-power-supply automatic conversion control circuit comprises a controller, a frequently-used power supply frequency acquisition unit, a standby power supply frequency acquisition unit, a frequently-used power supply voltage acquisition unit, a standby power supply voltage acquisition unit and a power supply switching driving unit, each of the normal / standby power supply frequency acquisition units comprises a step-down filter circuit, a signal conditioning circuit, a DC bias circuit, a signal amplification circuit and a signal isolation circuit, the input end of the step-down filter circuit is connected with an external normal / standby power supply, and the output end of the step-down filter circuit and the output end of the DC bias circuit are respectively connected with the input end of the signal conditioning circuit; the output end of the signal conditioning circuit is connected with the input end of the signal amplification circuit, and the output end of the signal amplification circuit is connected with the signal isolation circuit. According to the normal / standby power supply frequency acquisition unit, the DC bias circuit is arranged to condition the power supply frequency signal, so that the quick response of the frequency acquisition unit to frequency detection is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to dual power supply changeover switch technical field, concretely relates to a dual power supply automatic changeover control circuit and dual power supply automatic changeover switch. BACKGROUND

[0002] Dual power supply automatic changeover switch is often used in important power supply occasions, which is connected to a normal power supply and a backup power supply. When the normal power supply suddenly fails or is powered off, the backup power supply is automatically put into operation through the changeover switch, and the changeover between the two power supplies can be performed as needed (for example, in response to an external instruction), ensuring the continuity and reliability of power supply to the load and allowing the equipment to still operate normally.

[0003] The existing dual power supply changeover control circuit usually only has a voltage detection circuit to detect the phase voltages of the normal power supply and the backup power supply, and to determine whether the voltage detection result is overvoltage, undervoltage, or open-phase. If the corresponding fault occurs, the normal and backup power supplies are switched. The power supply frequency of the normal power supply and the backup power supply is also an important parameter of the alternating power supply. If the power supply frequency is unstable, it will affect the normal operation of the subsequent load of the power supply circuit. The existing dual power supply automatic changeover switch cannot accurately detect the frequency of the normal and backup power supplies, resulting in misjudgment in switching the normal and backup power supplies. SUMMARY

[0004] To solve the above problems, the technical solution provided by the utility model is as follows:

[0005] A dual power supply automatic changeover control circuit includes a controller, a normal power supply frequency acquisition unit, a backup power supply frequency acquisition unit, a normal power supply voltage acquisition unit, a backup power supply voltage acquisition unit, and a power supply switching drive unit. The input end of the normal power supply frequency acquisition unit and the input end of the normal power supply voltage acquisition unit are connected to an external normal power supply. The input end of the backup power supply frequency acquisition unit and the input end of the backup power supply voltage acquisition unit are connected to an external backup power supply. The output end of the normal power supply frequency acquisition unit, the output end of the backup power supply frequency acquisition unit, the output end of the normal power supply voltage acquisition unit, and the output end of the backup power supply voltage acquisition unit are connected to the input end of the controller. The output end of the controller is connected to the input end of the power supply switching drive unit. The normal power supply frequency acquisition unit and the backup power supply frequency acquisition unit each include a voltage reduction filter circuit, a signal conditioning circuit, a direct current bias circuit, a signal amplification circuit, and a signal isolation circuit. The input end of the voltage reduction filter circuit is connected to an external normal / backup power supply. The output end of the voltage reduction filter circuit and the output end of the direct current bias circuit are connected to the input end of the signal conditioning circuit. The output end of the signal conditioning circuit is connected to the input end of the signal amplification circuit. The output end of the signal amplification circuit is connected to the signal isolation circuit.

[0006] The utility model further sets up as signal conditioning circuitry includes operational amplifier U1 and resistance R8, the output of voltage reduction filter circuit and the output of direct current bias circuit connects the same phase input end of operational amplifier U1, the opposite phase input end of operational amplifier U1 is connected with the output of operational amplifier U1, one end of resistance R8 connects the output of operational amplifier U1, the other end of resistance R8 connects the input of signal amplification circuit.

[0007] The utility model further sets up as direct current bias circuit includes resistance R6, resistance R7 and triode Q1, one end of resistance R6 and one end of resistance R7 are connected high level respectively, the other end of resistance R6 connects the collector of triode Q1, the other end of resistance R7 connects the base of triode Q1, the emitter of triode Q1 connects the same phase input end of operational amplifier U1.

[0008] The utility model further sets up as voltage reduction filter circuit includes resistance R1, resistance R2, resistance R3, resistance R4, resistance R5, electric capacity C1, electric capacity C2 and electric capacity C3, both ends of electric capacity C1 connect external normal power supply / stand -by power supply, resistance R1, resistance R3 and electric capacity C3 are connected in proper order, resistance R2 and resistance R5 are connected in series, one end of resistance R1 and one end of resistance R2 are connected both ends of electric capacity C1 respectively, one end of resistance R5 and one end of electric capacity C3 are connected the same phase input end of operational amplifier U1 respectively, one end of resistance R4 connects the other end of resistance R1, the other end of resistance R4 connects the other end of resistance R2, one end of electric capacity C2 connects the other end of electric capacity C3, the other end of electric capacity C2 is connected resistance R5's other end and ground respectively.

[0009] The utility model further sets up as signal amplification circuit includes resistance R9, resistance R10, resistance R11, operational amplifier U2, electric capacity C4, electric capacity C5 and diode D1, the same phase input end of operational amplifier U2, one end of resistance R10 and one end of C5 are connected high level respectively, the other end of resistance R10 is connected one end of resistance R9, one end of electric capacity C4 and the opposite phase input end of operational amplifier U2 respectively, the other end of resistance R9, the other end of electric capacity C4 and the other end of electric capacity C5 all ground, the output of operational amplifier U2 connects the anode of diode D1, the cathode of diode D1 connects one end of resistance R11, the other end of resistance R11 connects the input of signal isolation circuit.

[0010] The utility model further sets up as signal isolation circuitry includes photoelectric coupler U3 and resistance R12, the positive pole of photoelectric coupler U3 connects another end of resistance R11, the negative pole of photoelectric coupler U3 is grounded, the collector of photoelectric coupler U3 connects high level, the emitter of photoelectric coupler U3 connects one end of resistance R12, another end of resistance R12 is grounded, and the emitter of photoelectric coupler U3 exports power frequency signal to the input end of controller.

[0011] The utility model further sets up still including normal power position detection unit and standby power position detection unit, the output of normal power position detection unit and the output of standby power position detection unit are connected respectively the input of controller.

[0012] The utility model further sets up still including power supply unit, the input of power supply unit is connected respectively normal power and standby power of outside, and power supply unit provides working voltage for controller, normal power frequency acquisition unit, standby power frequency acquisition unit, normal power voltage acquisition unit, standby power voltage acquisition unit and power switch drive unit.

[0013] The utility model further sets up still including communication unit and display and alarm unit, communication unit is connected with controller, and the output of controller is connected the input of display and alarm unit.

[0014] A dual power automatic transfer switch includes the dual power automatic transfer control circuit.

[0015] Compared with the prior art, the technical scheme has the following beneficial effects:

[0016] The normal / standby power frequency acquisition unit of the dual power automatic transfer control circuit improves the rapid response of the frequency detection of the frequency acquisition unit by setting the DC bias circuit to regulate the power frequency signal, realizes accurate frequency signal acquisition, and sends the power frequency signal to the controller through signal amplification and signal isolation, and the controller controls the power switch drive unit to work according to the signal, so that the normal standby power is accurately switched. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The utility model embodiment dual power automatic transfer control circuit principle block diagram.

[0018] Figure 2 The utility model embodiment normal / standby power frequency acquisition unit principle block diagram.

[0019] Figure 3The utility model discloses an embodiment common / stand -by power frequency acquisition unit circuit principle diagram. DETAILED DESCRIPTION

[0020] In order to further understand the content of the utility model, the utility model is described in detail in combination with the drawings and the embodiment.

[0021] It needs to be explained that the embodiment in the utility model and the features in the embodiment can be combined mutually without conflict.

[0022] In the description of the utility model, it needs to be explained that unless another explicit provision and limitation, the terms "mount", "connect", "connection" should be understood in broad sense, for example, can be fixed connection, integrally connected, can also be detachable connection, can be mechanical connection or electric connection, also can be the intercommunication of two elements, can be directly connected, also can be indirectly connected through intermediate medium, for the ordinary skilled in the art, the specific meaning of the above-mentioned terms can be understood according to specific circumstances.

[0023] Embodiment 1

[0024] In combination with the drawings Figure 1 to the drawings Figure 3 The utility model technical scheme is a kind of dual power automatic conversion control circuit, including controller 1, common power frequency acquisition unit 3, stand -by power frequency acquisition unit 5, common power voltage acquisition unit 2, stand -by power voltage acquisition unit 4 and power switching drive unit 9;The input end of the common power frequency acquisition unit 3 and the input end of the common power voltage acquisition unit 2 are connected with external common power source a respectively, the input end of the stand -by power frequency acquisition unit 5 and the input end of the stand -by power voltage acquisition unit 4 are connected with external stand -by power source b respectively, the output end of the common power frequency acquisition unit 3, the output end of the stand -by power frequency acquisition unit 5, the output end of the common power voltage acquisition unit 2 and the output end of the stand -by power voltage acquisition unit 4 are connected with the input end of the controller 1 respectively, the output end of the controller 1 is connected with the input end of the power switching drive unit 9;The common power frequency acquisition unit 3 and the stand -by power frequency acquisition unit 5 all include voltage reduction filter circuit 100, signal conditioning circuit 200, direct current bias circuit 300, signal amplification circuit 400 and signal isolation circuit 500, the input end of the voltage reduction filter circuit 100 is connected with external common power source a / stand -by power source b, the output end of the voltage reduction filter circuit 100 and the output end of the direct current bias circuit 300 are connected with the input end of the signal conditioning circuit 200 respectively, the output end of the signal conditioning circuit 200 is connected with the input end of the signal amplification circuit 400, the output end of the signal amplification circuit 400 is connected with the signal isolation circuit 500.

[0025] In the above embodiment, the voltage of the external normal power supply a / backup power supply b is reduced and filtered by the voltage reduction filter circuit 100, and a signal that can be coupled with a subsequent circuit is output; the direct current bias circuit 300 plays a role of direct current bias and impedance matching.

[0026] In the embodiment, the signal conditioning circuit 200 comprises an operational amplifier U1 and a resistor R8, the output end of the voltage reduction filter circuit and the output end of the direct current bias circuit are connected to the non-inverting input end of the operational amplifier U1, the inverting input end of the operational amplifier U1 is connected to the output end of the operational amplifier U1, one end of the resistor R8 is connected to the output end of the operational amplifier U1, and the other end of the resistor R8 is connected to the input end of the signal amplification circuit.

[0027] In the above embodiment, the model of the operational amplifier U1 is LM324, and the model of the following operational amplifier U2 is also LM324.

[0028] In the embodiment, the direct current bias circuit 300 comprises a resistor R6, a resistor R7 and a transistor Q1, one end of the resistor R6 and one end of the resistor R7 are respectively connected to a high level, the other end of the resistor R6 is connected to the collector of the transistor Q1, the other end of the resistor R7 is connected to the base of the transistor Q1, and the emitter of the transistor Q1 is connected to the non-inverting input end of the operational amplifier U1.

[0029] In the above embodiment, the direct current bias circuit 300 composed of the resistor R6, the resistor R7 and the transistor Q1 can play a role of impedance matching for the input end of the operational amplifier U1.

[0030] In the embodiment, the voltage reduction filter circuit 100 comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a capacitor C1, a capacitor C2 and a capacitor C3, the capacitor C1 is connected to the external normal power supply / backup power supply, the resistor R1, the resistor R3 and the capacitor C3 are connected in series, the resistor R2 and the resistor R5 are connected in series, one end of the resistor R1 and one end of the resistor R2 are respectively connected to the two ends of the capacitor C1, one end of the resistor R5 and one end of the capacitor C3 are respectively connected to the non-inverting input end of the operational amplifier U1, one end of the resistor R4 is connected to the other end of the resistor R1, the other end of the resistor R4 is connected to the other end of the resistor R2, one end of the capacitor C2 is connected to the other end of the capacitor C3, and the other end of the capacitor C2 is respectively connected to the other end of the resistor R5 and the ground.

[0031] In the embodiment, the signal amplification circuit 400 comprises resistors R9, R10, R11, an operational amplifier U2, capacitors C4, C5 and a diode D1, one end of the resistor R10 and one end of the C5 are connected to high level, the other end of the resistor R10 is connected to one end of the resistor R9, one end of the capacitor C4 and the inverting input terminal of the operational amplifier U2, the other end of the resistor R9, the other end of the capacitor C4 and the other end of the capacitor C5 are grounded, the output terminal of the operational amplifier U2 is connected to the positive electrode of the diode D1, the negative electrode of the diode D1 is connected to one end of the resistor R11, and the other end of the resistor R11 is connected to the input terminal of the signal isolation circuit.

[0032] In the embodiment, the signal isolation circuit 500 comprises an optical coupler U3 and a resistor R12, the other end of the resistor R11 is connected to the positive electrode of the optical coupler U3, the negative electrode of the optical coupler U3 is grounded, the collector of the optical coupler U3 is connected to high level, one end of the resistor R12 is connected to the emitter of the optical coupler U3, and the other end of the resistor R12 is grounded, and the emitter of the optical coupler U3 outputs a power frequency signal to the input terminal of the controller.

[0033] In the above embodiment, the signal isolation circuit 500 can realize electrical isolation between the controller side and the normal / backup power supply side, avoiding the influence of external power failure on the subsequent circuit.

[0034] In the embodiment, a normal power supply position detection unit 7 and a backup power supply position detection unit 8 are further included, the output terminal of the normal power supply position detection unit 7 and the output terminal of the backup power supply position detection unit 8 are respectively connected to the input terminal of the controller 1.

[0035] In the above embodiment, the normal power supply position detection unit 7 and the backup power supply position detection unit 8 use microswitches to detect the opening and closing actions of the double power supply circuit breaker to realize state acquisition.

[0036] In the embodiment, a power supply unit 6 is further included, the input terminal of the power supply unit 6 is connected to an external normal power supply a and a backup power supply b respectively, and the power supply unit 6 provides working voltage for the controller 1, the normal power supply frequency acquisition unit 3, the backup power supply frequency acquisition unit 5, the normal power supply voltage acquisition unit 2, the backup power supply voltage acquisition unit and the power switching driving unit 4.

[0037] In the embodiment, a communication unit 10 and a display and alarm unit 11 are further included, the communication unit 10 is connected to the controller 1, and the output terminal of the controller 1 is connected to the input terminal of the display and alarm unit 11.

[0038] The normal / backup power frequency acquisition unit of the dual power automatic transfer control circuit of the embodiment improves the fast response of the frequency acquisition unit to frequency detection, realizes accurate frequency signal acquisition, and sends the power frequency signal to the controller through signal amplification and signal isolation, the controller controls the power switching drive unit to work according to the signal, and realizes accurate switching of the normal / backup power.

[0039] Embodiment 2

[0040] The technical scheme of the utility model is a dual power automatic transfer switch, which comprises the dual power automatic transfer control circuit of embodiment 1.

[0041] The utility model and its embodiments are described above, which is not restrictive, and the drawings shown are only one of the embodiments of the utility model, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired, without departing from the creative purpose of the utility model, similar structure and embodiments can be designed without creativity, which should belong to the protection scope of the utility model.

Claims

1. A dual automatic transfer control circuit, characterized by comprising: The utility model provides an electric power supply switching control circuit, including controller, general power frequency acquisition unit, standby power frequency acquisition unit, general power voltage acquisition unit, standby power voltage acquisition unit and power switching drive unit, the input of general power frequency acquisition unit and the input of general power voltage acquisition unit are connected with external general power respectively, the input of standby power frequency acquisition unit and the input of standby power voltage acquisition unit are connected with external standby power respectively, the output of general power frequency acquisition unit, the output of standby power frequency acquisition unit, the output of general power voltage acquisition unit and the output of standby power voltage acquisition unit are connected with the input of controller respectively, the output of controller is connected with the input of power switching drive unit, general power frequency acquisition unit and standby power frequency acquisition unit all include voltage reduction filter circuit, signal conditioning circuit, direct current bias circuit, signal amplification circuit and signal isolation circuit, the input of voltage reduction filter circuit is connected with external general power / standby power, the output of voltage reduction filter circuit and the output of direct current bias circuit are connected with the input of signal conditioning circuit respectively, the output of signal conditioning circuit is connected with the input of signal amplification circuit, the output of signal amplification circuit is connected with signal isolation circuit.

2. The dual automatic transfer control circuit according to claim 1, wherein, The signal conditioning circuit includes an operational amplifier U1 and a resistor R8, the output of the voltage reduction filter circuit and the output of the direct current bias circuit are connected to the non-inverting input of the operational amplifier U1, the inverting input of the operational amplifier U1 is connected to the output of the operational amplifier U1, one end of the resistor R8 is connected to the output of the operational amplifier U1, and the other end of the resistor R8 is connected to the input of the signal amplification circuit.

3. The dual automatic transfer control circuit according to claim 2, wherein, The direct current bias circuit includes a resistor R6, a resistor R7, and a transistor Q1, one end of the resistor R6 and one end of the resistor R7 are connected to a high level, the other end of the resistor R6 is connected to the collector of the transistor Q1, the other end of the resistor R7 is connected to the base of the transistor Q1, and the emitter of the transistor Q1 is connected to the non-inverting input of the operational amplifier U1.

4. The dual automatic transfer control circuit of claim 2, wherein, The voltage reduction filter circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a capacitor C1, a capacitor C2, and a capacitor C3, both ends of the capacitor C1 are connected to an external general power / standby power, the resistor R1, the resistor R3, and the capacitor C3 are connected in series, the resistor R2 and the resistor R5 are connected in series, one end of the resistor R1 and one end of the resistor R2 are connected to both ends of the capacitor C1, one end of the resistor R5 and one end of the capacitor C3 are connected to the non-inverting input of the operational amplifier U1, one end of the resistor R4 is connected to the other end of the resistor R1, the other end of the resistor R4 is connected to the other end of the resistor R2, one end of the capacitor C2 is connected to the other end of the capacitor C3, and the other end of the capacitor C2 is connected to the other end of the resistor R5 and the ground, respectively.

5. The dual automatic transfer control circuit of claim 2, wherein, The signal amplification circuit comprises resistance R9, resistance R10, resistance R11, operational amplifier U2, capacitor C4, capacitor C5 and diode D1, one end of the resistance R10 and one end of the C5 are connected to high level respectively, the other end of the resistance R10 is connected to one end of the resistance R9, one end of the capacitor C4 and the inverting input of the operational amplifier U2 respectively, the other end of the resistance R9, the other end of the capacitor C4 and the other end of the capacitor C5 are grounded, the output of the operational amplifier U2 is connected to the positive electrode of the diode D1, the negative electrode of the diode D1 is connected to one end of the resistance R11, the other end of the resistance R11 is connected to the input of the signal isolation circuit.

6. The dual automatic transfer control circuit of claim 5, wherein, The signal isolation circuit comprises optical coupling U3 and resistance R12, the other end of the resistance R11 is connected to the positive electrode of the optical coupling U3, the negative electrode of the optical coupling U3 is grounded, the collector of the optical coupling U3 is connected to high level, the emitter of the optical coupling U3 is connected to one end of the resistance R12, the other end of the resistance R12 is grounded, the emitter of the optical coupling U3 outputs power frequency signal to the input of the controller.

7. The dual automatic transfer control circuit according to any one of claims 1 to 6, wherein The common power supply position detection unit and the backup power supply position detection unit are further included, the output of the common power supply position detection unit and the output of the backup power supply position detection unit are connected to the input of the controller respectively.

8. The dual automatic transfer control circuit according to any one of claims 1 to 6, wherein The power supply unit is further included, the input of the power supply unit is connected to the external common power supply and backup power supply respectively, the power supply unit provides working voltage for the controller, the common power supply frequency acquisition unit, the backup power supply frequency acquisition unit, the common power supply voltage acquisition unit, the backup power supply voltage acquisition unit and the power switching driving unit.

9. The dual automatic transfer control circuit according to any one of claims 1 to 6, wherein The communication unit and the display and alarm unit are further included, the communication unit is connected to the controller, the output of the controller is connected to the input of the display and alarm unit.

10. A dual automatic transfer switch, characterized by The dual power supply automatic conversion control circuit is included. The dual power supply automatic conversion control circuit is included.

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