Dual-power switching circuit and system

Abstract

The utility model discloses a dual-power switching circuit and system, which relates to the technical field of power electronics and comprises a first live wire, a first null line, a second live wire, a second null line, a first main relay and a second main relay. The first live wire is connected with the second live wire, and the first null line is connected with the second null line; a control coil of the first main relay is connected in series with a normally closed contact of the second main relay and then is connected with the first live wire and the first null line, and a first normally open contact of the first main relay is arranged on the first live wire and the first null line; a control coil of the second main relay is connected in series with a normally closed contact of the first main relay and then is connected with the second live wire and the second null line; and a first normally open contact of the second main relay is arranged on the second live wire and the second null line. The two paths of power supplies have no main-auxiliary relation, which path supplies power firstly does not need to be specified, and the circuit is more convenient to use.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of power electronics, especially a dual power switching circuit and system. BACKGROUND

[0002] At present, in the industrial control or power electronic equipment, some systems or equipment with higher system reliability requirements usually adopt main and auxiliary two power supply, and when the main loop power supply fails, it can be switched to auxiliary power supply.

[0003] However, the power supply circuit is divided into main and auxiliary two loops, and only the main loop power supply can be used preferentially when power on, and only the auxiliary power supply is switched when the main loop power supply is powered off, which is inconvenient to use. SUMMARY

[0004] The utility model embodiment provides a dual power switching circuit and system to solve the technical problem of the prior art that the existing dual power switching circuit is divided into main and auxiliary two loops, and only the main loop power supply can be used preferentially when power on, and only the auxiliary power supply is switched when the main loop power supply is powered off.

[0005] In a first aspect, a dual power switching circuit is provided, comprising: a first live wire, a first neutral wire, a second live wire, a second neutral wire, a first main relay and a second main relay;

[0006] The first live wire is connected to the second live wire, and the first neutral wire is connected to the second neutral wire.

[0007] The control coil of the first main relay is connected to the first live wire and the first neutral wire in series with the normally closed contact of the second main relay, and the first normally open contact of the first main relay is arranged on the first live wire and the first neutral wire.

[0008] The control coil of the second main relay is connected to the second live wire and the second neutral wire in series with the normally closed contact of the first main relay, and the first normally open contact of the second main relay is arranged on the second live wire and the second neutral wire.

[0009] In some embodiments, the dual power switching circuit further comprises: a first auxiliary relay, a second auxiliary relay, a first control circuit and a second control circuit.

[0010] The first control circuit is connected to the first live wire, the first neutral wire, the second normally open contact of the first main relay and the control coil of the first auxiliary relay.

[0011] The second control circuit is connected to the second live wire, the second neutral wire, the second normally open contact of the second main relay and the control coil of the second auxiliary relay.

[0012] a normally closed contact of the first auxiliary relay is connected in series with a control coil of the first main relay and a normally closed contact of the second main relay, and a normally closed contact of the second auxiliary relay is connected in series with a control coil of the second main relay and a normally closed contact of the first main relay;

[0013] When the first live wire and the first zero wire are powered, if a voltage between the first live wire and the first zero wire exceeds a preset interval, the first control circuit is configured to control a control coil of the first auxiliary relay to be powered;

[0014] When the second live wire and the second zero wire are powered, if a voltage between the second live wire and the second zero wire exceeds a preset interval, the second control circuit is configured to control a control coil of the second auxiliary relay to be powered.

[0015] In some embodiments, the first control circuit comprises a first proportional attenuation circuit, a first analog-to-digital converter, a first bidirectional limiting comparator and a first driving circuit connected in sequence;

[0016] The first proportional attenuation circuit is connected with the first live wire and the first zero wire;

[0017] The first driving circuit is connected with a second normally open contact of the first main relay and a control coil of the first auxiliary relay.

[0018] In some embodiments, the second control circuit comprises a second proportional attenuation circuit, a second analog-to-digital converter, a second bidirectional limiting comparator and a second driving circuit connected in sequence;

[0019] The second proportional attenuation circuit is connected with the second live wire and the second zero wire;

[0020] The second driving circuit is connected with a second normally open contact of the second main relay and a control coil of the second auxiliary relay.

[0021] In some embodiments, the first proportional attenuation circuit and the second proportional attenuation circuit each comprise a plurality of resistors connected in series.

[0022] In some embodiments, the first analog-to-digital converter and the second analog-to-digital converter are CMOS switch type digital-to-analog converters.

[0023] In some embodiments, the dual power supply switching circuit further comprises:

[0024] an AC-DC conversion circuit, the AC-DC conversion circuit being connected with a common terminal of the first live wire and the second live wire and a common terminal of the first zero wire and the second zero wire, and the AC-DC conversion circuit being connected with the first control circuit and the second control circuit.

[0025] In some embodiments, the dual power switching circuit further comprises:

[0026] a first circuit breaker disposed on the first live wire and the first neutral wire.

[0027] In some embodiments, the dual power switching circuit further comprises:

[0028] a second circuit breaker disposed on the second live wire and the second neutral wire.

[0029] In a second aspect, a dual power switching system is provided, comprising the dual power switching circuit as described above.

[0030] The beneficial effects brought by the technical solutions of the present application include:

[0031] The dual power switching circuit and system provided by the present application embodiment has no master and auxiliary relationship between the two power supplies, and does not need to specify which power supply must be powered first, and the two power supplies are interlocked, as long as one of the power supplies is working, the other power supply is in standby state, and when one of the power supplies is powered off, the other standby power supply can be quickly switched to the power supply state, and the circuit is more convenient to use.

[0032] The dual power switching circuit can also monitor the voltage amplitude of the two power supplies in real time, and when the voltage amplitude of the power supply being powered exceeds a certain range, it can be actively switched to the standby power supply for power supply, achieving the purpose of active switching. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0034] Figure 1 A structural schematic diagram of a dual power switching circuit provided by the present application embodiment. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described in the following with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

[0036] The utility model embodiments provide a kind of dual power supply switching circuit, it can solve the existing dual power supply switching circuit is divided into main auxiliary two loops, power on only priority to adopt main loop power supply, when main loop power supply is powered off, it is switched to auxiliary power supply, there is the technical problem of inconvenient use.

[0037] Referring to Figure 1 The utility model embodiments provide a kind of dual power supply switching circuit, including: first firewire L1, first zero line N1, second firewire L2, second zero line N2, first main relay KM1 and second main relay KM2.

[0038] The first firewire L1 is connected with the second firewire L2, and the first zero line N1 is connected with the second zero line N2.

[0039] The control coil (A1, A2) of the first main relay KM1 is connected with the normally closed contact (21, 22) of the second main relay KM2 after series connection, and the first firewire L1 and the first zero line N1 are connected, and the first normally open contact (1, 2, 3, 4) of the first main relay KM1 is arranged on the first firewire L1 and the first zero line N1.

[0040] The control coil (A1, A2) of the second main relay KM2 is connected with the normally closed contact (21, 22) of the first main relay KM1 after series connection, and the second firewire L2 and the second zero line N2 are connected, and the first normally open contact (1, 2, 3, 4) of the second main relay KM2 is arranged on the second firewire L2 and the second zero line N2.

[0041] During the circuit operation, the first live wire L1, the first neutral wire N1, the second live wire L2 and the second neutral wire N2 are powered, and it is assumed that the first live wire L1 and the first neutral wire N1 are powered first, the control coil (A1, A2) of the first main relay KM1 is powered, the first normally open contact (1, 2, 3, 4) of the first main relay KM1 is closed, the first live wire L1 and the first neutral wire N1 supply power to the subsequent circuit, and meanwhile the normally closed contact (21, 22) of the first main relay KM1 is opened, the control coil (A1, A2) of the second main relay KM2 is prevented from being powered, and simultaneous operation of the two power supplies is avoided.

[0042] Similarly, it is assumed that the second live wire L2 and the second neutral wire N2 are powered first, the control coil (A1, A2) of the second main relay KM2 is powered, the first normally open contact (1, 2, 3, 4) of the second main relay KM2 is closed, the second live wire L2 and the second neutral wire N2 supply power to the subsequent circuit, and meanwhile the normally closed contact (21, 22) of the second main relay KM2 is opened, the control coil (A1, A2) of the first main relay KM1 is prevented from being powered, and simultaneous operation of the two power supplies is avoided. When the second live wire L2 and the second neutral wire N2 are powered unexpectedly, the control coil (A1, A2) of the second main relay KM2 is powered, the first normally open contact (1, 2, 3, 4) of the second main relay KM2 is closed, the normally closed contact (21, 22) of the second main relay KM2 is closed, the control coil (A1, A2) of the first main relay KM1 is powered, and the first live wire L1 and the first neutral wire N1 supply power to the subsequent circuit.

[0043] The dual-power supply switching circuit in the embodiment of the utility model, two power supplies have no master and auxiliary relationship, and it is unnecessary to specify which power supply must be powered first, the two power supplies are interlocked, as long as one of the power supplies works, the other power supply is in a standby state, and when one of the power supplies is powered off, the other standby power supply can be rapidly switched to a power supply state, and the circuit is more convenient to use.

[0044] As an optional implementation, in one embodiment of the utility model, referring to Figure 1 The dual-power supply switching circuit further comprises a first auxiliary relay KA1, a second auxiliary relay KA2, a first control circuit and a second control circuit.

[0045] The first control circuit is connected with the first live wire L1, the first neutral wire N1, the second normally open contact (13, 14) of the first main relay KM1 and the control coil of the first auxiliary relay KA1.

[0046] The second control circuit is connected with the second live wire L2, the second neutral wire N2, the second normally open contact (13, 14) of the second main relay KM2 and the control coil of the second auxiliary relay KA2.

[0047] The normally closed contact (4, 12) of the first auxiliary relay KA1 is connected in series with the control coil (A1, A2) of the first main relay KM1 and the normally closed contact (21, 22) of the second main relay KM2, and the normally closed contact (4, 12) of the second auxiliary relay KA2 is connected in series with the control coil (A1, A2) of the second main relay KM2 and the normally closed contact (21, 22) of the first main relay KM1.

[0048] When the first live wire L1 and the first neutral wire N1 are powered, if the voltage between the first live wire L1 and the first neutral wire N1 exceeds a preset interval (for example, 200V-240V), the first control circuit is used to control the control coil of the first auxiliary relay KA1 to be powered.

[0049] When the second live wire L2 and the second neutral wire N2 are powered, if the voltage between the second live wire L2 and the second neutral wire N2 exceeds a preset interval (for example, 200V-240V), the second control circuit is used to control the control coil of the second auxiliary relay KA2 to be powered.

[0050] Referring to Figure 1 As shown, the normal mains is 220V, assuming that the circuit is powered by the first live wire L1 and the first neutral wire N1, after a period of time, if the voltage between the first live wire L1 and the first neutral wire N1 is lower than 200V or higher than 240V, if the state signal fed back by the second normally open contact (13, 14) of the first main relay KM1 shows that the circuit is indeed powered by the first live wire L1 and the first neutral wire N1, the first control circuit controls the control coil of the first auxiliary relay KA1 to be powered, through the first auxiliary relay KA1, the control coil of the first main relay KM1 is de-energized, the normally closed contact (21, 22) of the first main relay KM1 is closed, the control coil of the second main relay KM2 is powered, and the circuit actively switches to be powered by the second live wire L2 and the second neutral wire N2. Similarly, if the circuit is powered by the first live wire L1 and the first neutral wire N1, the corresponding active switching can also be performed.

[0051] As an optional implementation, in one utility model embodiment, referring to Figure 1 The first control circuit comprises, in sequence, a first proportional attenuation circuit, a first analog-to-digital converter, a first bidirectional limiting comparator, and a first driving circuit.

[0052] The first proportional attenuation circuit is connected with the first live wire and the first neutral wire, and the first driving circuit is connected with the second normally open contact of the first main relay and the control coil of the first auxiliary relay.

[0053] For example, when the normal mains supply is 220V, the proportional attenuation is performed by the first proportional attenuation circuit, the approximately 220V alternating voltage is converted into a sine small signal of about 5V, and then the signal is converted into a digital signal by the first analog-to-digital converter and enters the first bidirectional limiting comparator. The first bidirectional limiting comparator comprises two hysteresis comparators. One hysteresis comparator compares the upper limit of the voltage. When the amplitude of the signal is greater than the reference of the comparator, the comparator flips, indicating that the amplitude of the power supply at this time is too large. The other hysteresis comparator compares the lower limit of the voltage. When the amplitude of the signal is less than the reference of the comparator, the comparator flips, indicating that the amplitude of the power supply at this time is too small. The main function of the first bidirectional limiting comparator is to limit the window of the voltage amplitude. When the amplitude of the power supply exceeds the window, a high level is output to the first driving circuit. In addition, if the state signal fed back by the second normally open contact (13, 14) of the first main relay KM1 to the first driving circuit shows that the circuit is indeed powered by the first live wire L1 and the first neutral wire N1, at this time, the first driving circuit sends a signal to control the control coil of the first auxiliary relay KA1 to be powered, and the control coil of the first main relay KM1 is de-energized through the first auxiliary relay KA1. The normally closed contact (21, 22) of the first main relay KM1 is closed, the control coil of the second main relay KM2 is powered, and the circuit is actively switched to be powered by the second live wire L2 and the second neutral wire N2. In addition, the first bidirectional limiting comparator outputs a high level to the first driving circuit, but the state signal fed back by the second normally open contact (13, 14) of the first main relay KM1 shows that the circuit is not powered by the first live wire L1 and the first neutral wire N1, and the first driving circuit does not control the control coil of the first auxiliary relay KA1 to be powered. The utility model embodiment can monitor the voltage amplitude of the two power supplies in real time. When the voltage amplitude of the power supply being powered exceeds a certain range, the circuit can be actively switched to be powered by the standby power supply, so as to achieve the purpose of active switching.

[0054] As an optional implementation, in one utility model embodiment, referring to Figure 1As shown, the second control circuit comprises a second proportional attenuation circuit, a second analog-to-digital converter, a second bidirectional limiting comparator and a second driving circuit connected in sequence, the second proportional attenuation circuit is connected with the second live wire L1 and the second neutral wire N1, and the second driving circuit is connected with the second normally open contact (13, 14) of the second main relay KM2 and the control coil of the second auxiliary relay KA2. The working principle of the second control circuit is similar to that of the first control circuit, and details are not repeated. Optionally, the first proportional attenuation circuit and the second proportional attenuation circuit each comprise a plurality of series resistors. The first analog-to-digital converter and the second analog-to-digital converter are CMOS switch type digital-to-analog converters.

[0055] As an optional implementation, in an utility model embodiment, referring to Figure 1 As shown, the dual power supply switching circuit further comprises an AC-DC conversion circuit, the AC-DC conversion circuit is connected with the common end of the first live wire L1 and the second live wire L2 and the common end of the first neutral wire N1 and the second neutral wire N2, and the AC-DC conversion circuit is connected with the first control circuit and the second control circuit. The AC-DC conversion circuit can convert the alternating current of the first live wire L1 and the first neutral wire N1 or the alternating current of the second live wire L2 and the second neutral wire N2 into direct current and provide the direct current for the first control circuit and the second control circuit.

[0056] As an optional implementation, in an utility model embodiment, referring to Figure 1 As shown, the dual power supply switching circuit further comprises a first circuit breaker, the first circuit breaker is arranged on the first live wire L1 and the first neutral wire N1, and the first circuit breaker can protect electrical elements on the first live wire L1 and the first neutral wire N1.

[0057] As an optional implementation, in an utility model embodiment, referring to Figure 1 As shown, the dual power supply switching circuit further comprises a second circuit breaker, the second circuit breaker is arranged on the second live wire L2 and the second neutral wire N2, and the second circuit breaker can protect electrical elements on the second live wire L2 and the second neutral wire N2.

[0058] The utility model embodiment provides a dual power supply switching system, comprising the dual power supply switching circuit.

[0059] In the description of this utility model, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0060] It should be noted that in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0061] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the present invention.

Claims

1. A dual power switching circuit, characterized by comprising: The dual power supply switching circuit comprises: a first live wire, a first neutral wire, a second live wire, a second neutral wire, a first main relay and a second main relay; the first live wire is connected with the second live wire, and the first neutral wire is connected with the second neutral wire; a control coil of the first main relay is connected with a normally closed contact of the second main relay in series, and then the first live wire and the first neutral wire are connected; a first normally open contact of the first main relay is arranged on the first live wire and the first neutral wire; a control coil of the second main relay is connected with a normally closed contact of the first main relay in series, and then the second live wire and the second neutral wire are connected; a first normally open contact of the second main relay is arranged on the second live wire and the second neutral wire.

2. The dual supply switching circuit of claim 1, wherein, Further comprising: a first auxiliary relay, a second auxiliary relay, a first control circuit and a second control circuit; the first control circuit is connected with the first live wire, the first neutral wire, a second normally open contact of the first main relay and a control coil of the first auxiliary relay; the second control circuit is connected with the second live wire, the second neutral wire, a second normally open contact of the second main relay and a control coil of the second auxiliary relay; a normally closed contact of the first auxiliary relay is connected with the control coil of the first main relay and the normally closed contact of the second main relay in series; a normally closed contact of the second auxiliary relay is connected with the control coil of the second main relay and the normally closed contact of the first main relay in series; when the first live wire and the first neutral wire are powered, if the voltage between the first live wire and the first neutral wire exceeds a preset interval, the first control circuit is used for controlling the control coil of the first auxiliary relay to be powered; when the second live wire and the second neutral wire are powered, if the voltage between the second live wire and the second neutral wire exceeds a preset interval, the second control circuit is used for controlling the control coil of the second auxiliary relay to be powered.

3. The dual power supply switching circuit according to claim 2, wherein: the first control circuit comprises a first proportional attenuation circuit, a first analog-to-digital converter, a first bidirectional limiting comparator and a first driving circuit connected in sequence; the first proportional attenuation circuit is connected with the first live wire and the first neutral wire; the first driving circuit is connected with the second normally open contact of the first main relay and the control coil of the first auxiliary relay.

4. The dual power supply switching circuit according to claim 3, wherein: the second control circuit comprises a second proportional attenuation circuit, a second analog-to-digital converter, a second bidirectional limiting comparator and a second driving circuit connected in sequence; the second proportional attenuation circuit is connected with the second live wire and the second neutral wire; the second driving circuit is connected with the second normally open contact of the second main relay and the control coil of the second auxiliary relay.

5. The dual power supply switching circuit according to claim 4, wherein: the first proportional attenuation circuit and the second proportional attenuation circuit each comprise a plurality of resistors connected in series.

6. The dual power supply switching circuit according to claim 4, wherein: The first analog-to-digital converter and the second analog-to-digital converter are both CMOS switch type digital-to-analog converters.

7. The dual power switching circuit of claim 2, wherein, Further comprising: An AC-DC conversion circuit connected with the common end of the first and second live wires and the common end of the first and second neutral wires, and connected with the first and second control circuits.

8. The dual power switching circuit of claim 1, wherein, Further comprising: A first circuit breaker arranged on the first live wire and the first neutral wire.

9. The dual power switching circuit of claim 1, wherein, Further comprising: A second circuit breaker arranged on the second live wire and the second neutral wire.

10. A dual power switching system, characterized by, The dual power supply switching circuit of any one of claims 1-9.

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