CN217956775U - Mode switching circuit and uninterrupted power supply - Google Patents

Abstract

The application belongs to the field of power supplies and provides a mode switching circuit and an uninterruptible power supply. The mode switching circuit comprises a first switch unit, a second switch unit, a third switch unit, a fourth switch unit, a transformer, an inverter unit, a charging unit and a battery unit. The charging unit is electrically connected with the battery unit, the battery unit is electrically connected with the inversion unit, the inversion unit is electrically connected with the secondary winding of the transformer, the primary winding of the transformer is electrically connected with the fourth switch unit and the second switch unit respectively, the fourth switch unit is electrically connected with the third switch unit, the first switch unit, the second switch unit and the charging unit are all electrically connected with the alternating current input end, the third switch unit and the first switch unit are all electrically connected with the first terminal of the alternating current output end, and the primary winding of the transformer, the first switch unit and the second switch unit are all electrically connected with the second terminal of the alternating current output end. The problem of off-line uninterrupted power source inefficiency in mains voltage normal range has been solved in this application.

Description

Mode switching circuit and uninterrupted power supply

Technical Field

The application belongs to the technical field of power supplies, and particularly relates to a mode switching circuit and an uninterruptible power supply.

Background

Single-phase off-line ups are now becoming more and more popular for use in everyday work and learning. Generally, the UPS can be used as a backup power supply of a computer, if a transient power failure occurs, the UPS can provide relatively stable voltage for the computer to use, and a user can have time to store own data. The advantages of the single-phase off-line uninterrupted power supply are that: 1. simple structure, small volume, light weight, easy control and low cost. 2. The conversion efficiency is high, and the switching time is short. 3. Has a perfect self-protection system, such as: emergency warning of low battery voltage, overcurrent and short circuit protection, end of discharge protection, etc. Therefore, the single-phase off-line uninterrupted power supply has great competitiveness in the market. However, when the mains voltage is in the normal range, the mains input is transmitted to the output end through the transformer, the transformer generates large loss, and the efficiency of the off-line uninterruptible power supply is reduced.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides a mode switching circuit and an uninterruptible power supply, and can solve the problem that an offline uninterruptible power supply is low in efficiency when the mains voltage is within a normal range.

In a first aspect, an embodiment of the present application provides a mode switching circuit, which includes a first switch unit, a second switch unit, a third switch unit, a fourth switch unit, a transformer, an inverter unit, a charging unit, and a battery unit;

the charging unit is electrically connected with the battery unit, the battery unit is electrically connected with the inversion unit, the inversion unit is electrically connected with a secondary winding of the transformer, a primary winding of the transformer is respectively electrically connected with the fourth switch unit and the second switch unit, the fourth switch unit is electrically connected with the third switch unit, the first switch unit, the second switch unit and the charging unit are all used for being electrically connected with a first terminal and a second terminal of an alternating current input end, the third switch unit and the first switch unit are all used for being electrically connected with a first terminal of an alternating current output end, and the primary winding of the transformer, the first switch unit and the second switch unit are all used for being electrically connected with a second terminal of the alternating current output end.

In a possible implementation manner of the first aspect, the primary winding of the transformer includes a first connection end, a second connection end, a first tap, and a second tap;

the first connecting end and the second tap of the primary winding of the transformer are electrically connected with the fourth switching unit, the first tap of the primary winding of the transformer is electrically connected with the second switching unit, and the second connecting end of the primary winding of the transformer is used for being electrically connected with the second terminal of the alternating current output end;

the secondary winding of the transformer comprises a third connection terminal and a fourth connection terminal; and the third connecting end and the fourth connecting end of the secondary winding of the transformer are electrically connected with the inverter unit.

In one possible implementation manner of the first aspect, the first switching unit includes a first relay; the first end of the first relay is used for being electrically connected with the first terminal of the alternating current input end, the second end of the first relay is used for being electrically connected with the second terminal of the alternating current input end, the third end of the first relay is used for being electrically connected with the first terminal of the alternating current output end, and the fourth end of the first relay is used for being electrically connected with the second terminal of the alternating current output end.

In one possible implementation manner of the first aspect, the second switching unit includes a second relay; the first end of the second relay is used for being electrically connected with the first terminal of the alternating current input end, the second end of the second relay is used for being electrically connected with the second terminal of the alternating current input end, the third end of the second relay is electrically connected with the primary winding of the transformer, and the fourth end of the second relay is used for being electrically connected with the second terminal of the alternating current output end.

In one possible implementation manner of the first aspect, the third switching unit includes a third relay; and a first end of the third relay is electrically connected with the fourth switch unit, and a second end of the third relay is electrically connected with a first terminal of the alternating current output end.

In one possible implementation manner of the first aspect, the fourth switching unit includes a fourth relay; the first end of the fourth relay is electrically connected with the third switch unit, and the second end of the fourth relay and the third end of the fourth relay are both electrically connected with the primary winding of the transformer.

In one possible implementation form of the first aspect, the battery unit includes a battery and a capacitor; the battery unit comprises a battery and a capacitor; the positive electrode of the battery is electrically connected with the charging unit, the first end of the capacitor and the inversion unit respectively, and the negative electrode of the battery is electrically connected with the charging unit, the second end of the capacitor and the inversion unit respectively.

In a possible implementation manner of the first aspect, the inverting unit includes a first switching tube, a second switching tube, a third switching tube, and a fourth switching tube;

the first end that switches on of first switch tube respectively with the first end that switches on of second switch tube with the battery unit electricity is connected, the second of first switch tube switch on the end respectively with the first end that switches on of third switch tube with the secondary winding electricity of transformer is connected, the second of second switch tube switch on the end respectively with the first end that switches on of fourth switch tube with the secondary winding electricity of transformer is connected, the second of third switch tube switch on the end respectively with the second end that switches on of fourth switch tube with the battery unit electricity is connected.

In a possible implementation manner of the first aspect, the first switch tube, the second switch tube, the third switch tube, and the fourth switch Guan Junwei NMOS tube.

In a second aspect, an embodiment of the present application provides an uninterruptible power supply, which includes the mode switching circuit provided in the first aspect of the embodiment of the present application.

Compared with the prior art, the embodiment of the application has the advantages that:

the embodiment of the application provides a mode switching circuit, which comprises a first switch unit, a second switch unit, a third switch unit, a fourth switch unit, a transformer, an inverter unit, a charging unit and a battery unit. The charging unit is electrically connected with the battery unit, the battery unit is electrically connected with the inversion unit, the inversion unit is electrically connected with the secondary winding of the transformer, the primary winding of the transformer is electrically connected with the fourth switch unit and the second switch unit respectively, the fourth switch unit is electrically connected with the third switch unit, the first switch unit, the second switch unit and the charging unit are all used for being electrically connected with the first terminal and the second terminal of the alternating current input end, the third switch unit and the first switch unit are all used for being electrically connected with the first terminal of the alternating current output end, and the primary winding of the transformer, the first switch unit and the second switch unit are all used for being electrically connected with the second terminal of the alternating current output end. When the voltage of the alternating current input end is within the preset range, the first switch unit is conducted, the second switch unit, the third switch unit and the fourth switch unit are turned off, the voltage of the alternating current input end is directly transmitted to the alternating current output end through the first switch unit without passing through a transformer, loss caused by the transformer is avoided, efficiency of the uninterruptible power supply is improved, and the purpose of energy conservation is achieved. The charging unit is used for charging the battery unit. The application provides a mode switching circuit has solved the problem that off-line uninterrupted power source efficiency is low when mains voltage is in normal range.

It is understood that the beneficial effects of the second aspect can be referred to the related description of the first aspect, and are not described herein again.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a schematic block diagram of a mode switching circuit provided in an embodiment of the present application;

FIG. 2 is a circuit diagram of a mode switching circuit according to an embodiment of the present disclosure;

fig. 3 is a schematic block diagram of an uninterruptible power supply according to another embodiment of the present application.

In the figure: 10. a first switch unit; 11. a first end of a first relay; 12. a second terminal of the first relay; 13. a third terminal of the first relay; 14. a fourth terminal of the first relay; 20. a second switching unit; 21. a first end of a second relay; 22. a second terminal of the second relay; 23. a third terminal of the second relay; 24. a fourth terminal of the second relay; 30. a third switching unit; 31. a first end of a third relay; 32. a second terminal of the third relay; 33. a third terminal of a third relay; 40. a fourth switching unit; 41. a first end of a fourth relay; 42. a second terminal of a fourth relay; 43. a third terminal of the fourth relay; 50. a transformer; 51. a first connection end; 52. a second connection end; 53. a third connection end; 54. a fourth connection end; 55. a first tap; 56. a second tap; 60. an inversion unit; 70. a battery cell; 80. a charging unit; 90. an alternating current input end; 100. an alternating current output end; 300. an uninterruptible power supply; 301. a mode switching circuit; 302. a detection circuit; 303. a control circuit.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

As used in the specification of this application and the appended claims, the term "if" may be interpreted contextually as "when …" or "once" or "in response to a determination" or "in response to a detection". Similarly, the phrase "if it is determined" or "if a [ described condition or event ] is detected" may be interpreted contextually to mean "upon determining" or "in response to determining" or "upon detecting [ described condition or event ]" or "in response to detecting [ described condition or event ]".

Furthermore, in the description of the present application and the appended claims, the terms "first," "second," "third," and the like are used for distinguishing between descriptions and not necessarily for describing or implying relative importance.

Reference throughout this specification to "one embodiment" or "some embodiments," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," or the like, in various places throughout this specification are not necessarily all referring to the same embodiment, but rather "one or more but not all embodiments" unless specifically stated otherwise. The terms "comprising," "including," "having," and variations thereof mean "including, but not limited to," unless expressly specified otherwise.

As shown in fig. 1, an embodiment of the present application provides a mode switching circuit, which includes a first switching unit 10, a second switching unit 20, a third switching unit 30, a fourth switching unit 40, a transformer 50, an inverter unit 60, a charging unit 80, and a battery unit 70. The charging unit 80 is electrically connected to the battery unit 70. The battery unit 70 is electrically connected to the inverter unit 60. The inverter unit 60 is electrically connected to the secondary winding of the transformer 50. The primary winding of the transformer 50 is electrically connected to the fourth switching unit 40 and the second switching unit 20, respectively. The fourth switching unit 40 is electrically connected to the third switching unit 30. The first switching unit 10, the second switching unit 20 and the charging unit 80 are all configured to be electrically connected to the first terminal L and the second terminal N of the ac input terminal 90. The third switching unit 30 and the first switching unit 10 are both configured to be electrically connected to the first terminal L' of the ac output terminal 100. The primary winding of the transformer 50, the first switching unit 10 and the second switching unit 20 are all configured to be electrically connected to the second terminal N' of the ac output terminal 100.

Specifically, when the voltage of the ac input terminal 90 is within the predetermined range, the mode switching circuit operates in the normal mode. At this time, the first switch unit 10 is controlled to be turned on, the second switch unit 20, the third switch unit 30 and the fourth switch unit 40 are controlled to be turned off, the voltage of the ac input terminal 90 is directly transmitted to the ac output terminal 100 through the first switch unit 10 without passing through the transformer 50, so that the loss caused by the transformer 50 is avoided, the efficiency of the uninterruptible power supply is improved, and the purpose of energy saving is achieved. The charging unit 80 is used to charge the battery unit 70. The application provides a mode switching circuit has solved the problem that off-line uninterrupted power source efficiency is low when mains voltage is in normal range.

When the voltage of the ac input terminal 90 is lower than the predetermined range and greater than the first threshold voltage, the mode switching circuit operates in the boost mode. At this time, the second switching unit 20, the third switching unit 30 and the fourth switching unit 40 are controlled to be turned on, and the first switching unit 10 is controlled to be turned off. The voltage at the ac input terminal 90 is boosted by the primary side boost winding of the transformer 50 and is delivered to the ac output terminal 100. The charging unit 80 is used to charge the battery cell 70. When the voltage of the ac input terminal 90 is low, the mode switching circuit provided in the embodiment of the present application can boost the voltage of the ac input terminal 90, thereby ensuring the normal operation of the uninterruptible power supply.

When the voltage of the ac input terminal 90 is higher than the predetermined range and lower than the second threshold voltage, the mode switching circuit operates in the buck mode. At this time, the second switching unit 20 and the third switching unit 30 are controlled to be turned on, and the first switching unit 10 and the fourth switching unit 40 are controlled to be turned off. The voltage at the ac input terminal 90 is stepped down by the primary step-down winding of the transformer 50 and is supplied to the ac output terminal 100. The charging unit 80 is used to charge the battery cell 70. When the voltage of the ac input terminal 90 is high, the mode switching circuit provided in the embodiment of the present application can step down the voltage of the ac input terminal 90, thereby ensuring the normal operation of the ups.

When the voltage at the ac input terminal 90 is greater than the second threshold voltage or less than the first threshold voltage, the mode switching circuit operates in the inverter mode. At this time, the third switching unit 30 is controlled to be turned on, and the first switching unit 10, the second switching unit 20, and the fourth switching unit 40 are controlled to be turned off. The battery unit 70 discharges, controls the inverter unit 60 to operate, converts the dc power output from the battery unit 70 into ac power through the inverter unit 60 and the transformer 50, and transmits the ac power to the ac output terminal 100. When the voltage at the ac input terminal 90 is abnormal, the mode switching circuit provided in the embodiment of the present application discharges electricity by using the battery unit 70, converts the dc power into the ac power through the inverter unit 60 and the transformer 50, and transmits the ac power to the ac output terminal 100, thereby ensuring the normal operation of the ups.

Further, the first switching unit 10, the second switching unit 20, the third switching unit 30, and the fourth switching unit 40 are electrically connected to a control circuit for controlling the first switching unit 10, the second switching unit 20, the third switching unit 30, and the fourth switching unit 40 to be turned on or off according to the voltage of the ac input terminal 90. The inverter unit 60 is electrically connected to a control circuit for controlling the inverter unit 60 to operate when the battery unit 70 is discharged. Wherein the control circuit is implemented by means of the prior art.

The second terminal N of the ac input terminal 90 and the second terminal N' of the ac output terminal 100 are both electrically connected to a neutral line.

As shown in fig. 2, the primary winding of the transformer 50 includes a first connection terminal 51, a second connection terminal 52, a first tap 55 and a second tap 56. The first connection terminal 51 and the second tap 56 of the primary winding of the transformer 50 are electrically connected to the fourth switching unit 40. The first tap 55 of the primary winding of the transformer 50 is electrically connected to the second switching unit 20. The second connection 52 of the primary winding of the transformer 50 is adapted to be electrically connected to the second terminal N' of the ac output 100. The secondary winding of the transformer 50 comprises a third connection 53 and a fourth connection 54. The third connection terminal 53 and the fourth connection terminal 54 of the secondary winding of the transformer 50 are both electrically connected to the inverter unit 60.

It should be noted that the number of turns of the coil between the first tap 55 and the second connection terminal 52 is smaller than the number of turns of the coil between the first connection terminal 51 and the second connection terminal 52. The number of coil turns between the first tap 55 and the second connection terminal 52 is greater than the number of coil turns between the second tap 56 and the second connection terminal 52.

Specifically, when the voltage of the ac input terminal 90 is lower than the predetermined range and greater than the first threshold voltage, the mode switching circuit operates in the boost mode. At this time, the second switch unit 20 is controlled to be turned on, so that the first terminal L of the ac input terminal 90 is electrically connected to the first tap 55 of the primary winding of the transformer 50, and the second terminal N of the ac input terminal 90 is electrically connected to the second terminal N' of the ac output terminal 100. When the third switching unit 30 and the fourth switching unit 40 are controlled to be turned on, the first connection end 51 of the primary winding of the transformer 50 is electrically connected to the first terminal L' of the ac output terminal 100. The first switching unit 10 is controlled to be turned off. The voltage at the ac input terminal 90 is boosted by the self-coupling principle of the winding between the first tap 55 and the second connection terminal 52 of the primary winding of the transformer 50 and the winding between the first connection terminal 51 and the second connection terminal 52 of the primary winding of the transformer 50, and is transmitted to the ac output terminal 100. The charging unit 80 is used to charge the battery cell 70. When the voltage of the ac input terminal 90 is low, the mode switching circuit provided in the embodiment of the present application can boost the voltage of the ac input terminal 90, thereby ensuring the normal operation of the uninterruptible power supply.

When the voltage of the ac input terminal 90 is higher than the predetermined range and lower than the second threshold voltage, the mode switching circuit operates in the buck mode. At this time, the second switching unit 20 is controlled to be turned on, so that the first terminal L of the ac input terminal 90 is electrically connected to the first tap 55 of the primary winding of the transformer 50, and the second terminal N of the ac input terminal 90 is electrically connected to the second terminal N' of the ac output terminal 100. The fourth switching unit 40 is controlled to be turned off, the third switching unit 30 is controlled to be turned on, and the second tap 56 of the primary winding of the transformer 50 is electrically connected to the first terminal L' of the ac output terminal 100. The first switching unit 10 is controlled to be turned off. The voltage at the ac input terminal 90 is reduced by the self-coupling principle of the winding between the first tap 55 and the second connection terminal 52 of the primary winding of the transformer 50 and the winding between the second tap 56 and the second connection terminal 52 of the primary winding of the transformer 50, and is delivered to the ac output terminal 100. The charging unit 80 is used to charge the battery cell 70. When the voltage of the ac input terminal 90 is high, the mode switching circuit provided in the embodiment of the present application can step down the voltage of the ac input terminal 90, thereby ensuring the normal operation of the ups.

When the voltage at the ac input terminal 90 is greater than the second threshold voltage or less than the first threshold voltage, the mode switching circuit operates in the inverter mode. At this time, the fourth switching unit 40 is controlled to be turned off, the third switching unit 30 is controlled to be turned on, and the second tap 56 of the primary winding of the transformer 50 is electrically connected to the first terminal L' of the ac output terminal 100. The first switching unit 10 and the second switching unit 20 are controlled to be turned off. The battery unit 70 discharges, controls the inverter unit 60 to operate, converts the dc power output from the battery unit 70 into ac power through the inverter unit 60 and the transformer 50, and transmits the ac power to the ac output terminal 100. When the voltage at the ac input terminal 90 is abnormal, the battery unit 70 in the mode switching circuit provided in the embodiment of the present application discharges, and the dc power is converted into the ac power through the inverter unit 60 and the transformer 50, and the ac power is transmitted to the ac output terminal 100, thereby ensuring the normal operation of the uninterruptible power supply.

As shown in fig. 2, the first switching unit 10 includes a first relay. The first end 11 of the first relay is adapted to be electrically connected to the first terminal L of the ac input 90. The second end 12 of the first relay is adapted to be electrically connected to the second terminal N of the ac input 90. The third terminal 13 of the first relay is used for electrically connecting with the first terminal L' of the ac output terminal 100. The fourth terminal 14 of the first relay is adapted to be electrically connected to the second terminal N' of the ac output 100.

Specifically, the first switch unit 10 is controlled to be turned on, that is, the first relay is controlled to be turned on, when the first relay is turned on, the first end 11 of the first relay and the third end 13 of the first relay are connected and turned on, and the second end 12 of the first relay and the fourth end 14 of the first relay are connected and turned on. The first switch unit 10 is controlled to be turned off, that is, the first relay is controlled to be turned off, when the first relay is turned off, the first terminal 11 of the first relay is disconnected from the third terminal 13 of the first relay, and the second terminal 12 of the first relay is disconnected from the fourth terminal 14 of the first relay.

Furthermore, the control end of the first relay is electrically connected with the control circuit. The control circuit is used for controlling the on or off of the first relay according to the voltage of the alternating current input end 90.

As shown in fig. 2, the second switching unit 20 includes a second relay. The first end 21 of the second relay is adapted to be electrically connected to the first terminal L of the ac input 90. The second relay second terminal 22 is adapted to be electrically connected to the second terminal N of the ac input terminal 90. The third terminal 23 of the second relay is electrically connected to the primary winding of the transformer 50. The fourth end 24 of the second relay is used to electrically connect to the second terminal N' of the ac output 100.

In particular, as can be seen from fig. 2, the third terminal 23 of the second relay is electrically connected to the first tap 55 of the primary winding of the transformer 50. The second switching unit 20 is controlled to be turned on, that is, the second relay is controlled to be turned on, when the second relay is turned on, the first terminal 21 of the second relay is connected to the third terminal 23 of the second relay and is turned on, and the second terminal 22 of the second relay is connected to the fourth terminal 24 of the second relay. The first terminal L of the ac input terminal 90 is electrically connected to the first tap 55 of the primary winding of the transformer 50 through the first terminal 21 of the second relay and the third terminal 23 of the second relay. The second terminal N of the ac input 90 is electrically connected to the second terminal N' of the ac output 100 via the second relay second terminal 22 and the second relay fourth terminal 24. The second switching unit 20 is controlled to be turned off, that is, the second relay is controlled to be turned off, when the second relay is turned off, the first terminal 21 of the second relay is disconnected from the third terminal 23 of the second relay, and the second terminal 22 of the second relay is disconnected from the fourth terminal 24 of the second relay.

Furthermore, the control end of the second relay is electrically connected with the control circuit. The control circuit is used for controlling the second relay to be switched on or switched off according to the voltage of the alternating current input end 90.

As shown in fig. 2, the third switching unit 30 includes a third relay. The first terminal 31 of the third relay is electrically connected to the fourth switching unit 40. The second end 32 of the third relay is adapted to be electrically connected to the first terminal L' of the ac output 100.

Specifically, in the third switching unit 30, the first terminal 31 of the third relay is a common COM terminal, the second terminal 32 of the third relay is a normally open terminal, and the third terminal 33 of the third relay is a normally closed terminal. Controlling the third switching unit 30 to be conductive, i.e. controlling the third relay to be conductive, connects the first terminal 31 of the third relay to the second terminal 32 of the third relay. The third switching unit 30 is controlled to be turned off, i.e. the third relay is controlled to be turned off, and then the first terminal 31 of the third relay is connected to the third terminal 33 of the third relay.

Furthermore, the control end of the third relay is electrically connected with the control circuit. The control circuit is used for controlling the third relay to be switched on or switched off according to the voltage of the alternating current input end 90.

As shown in fig. 2, the fourth switching unit 40 includes a fourth relay. The first end 41 of the fourth relay is electrically connected to the third switching unit 30. The second terminal 42 of the fourth relay and the third terminal 43 of the fourth relay are both electrically connected to the primary winding of the transformer 50.

Specifically, as can be seen from fig. 2, the first terminal 41 of the fourth relay is electrically connected to the first terminal 31 of the third relay in the third switching unit 30, the second terminal 42 of the fourth relay is electrically connected to the first connection terminal 51 of the primary winding of the transformer 50, and the third terminal 43 of the fourth relay is electrically connected to the second tap 56 of the primary winding of the transformer 50. The first terminal 41 of the fourth relay in the fourth switching unit 40 is a common COM terminal, the second terminal 42 of the fourth relay is a normally open terminal, and the third terminal 43 of the fourth relay is a normally closed terminal. Controlling the fourth switching unit 40 to be conductive, i.e. controlling the fourth relay to be conductive, connects the first terminal 41 of the fourth relay to the second terminal 42 of the fourth relay. The fourth switching unit 40 is controlled to be turned off, i.e. the fourth relay is controlled to be turned off, and then the first terminal 41 of the fourth relay is connected to the third terminal 43 of the fourth relay.

Furthermore, the control end of the fourth relay is electrically connected with the control circuit. The control circuit is used for controlling the fourth relay to be switched on or switched off according to the voltage of the alternating current input end 90.

As shown in fig. 2, the battery unit 70 includes a battery BAT and a capacitor C. The positive electrode of the battery BAT is electrically connected with the charging unit 80, the first end of the capacitor C and the inverter unit 60, respectively, and the negative electrode of the battery BAT is electrically connected with the charging unit 80, the second end of the capacitor C and the inverter unit 60, respectively.

Specifically, when the mode switching circuit operates in the normal mode, the step-up mode, and the step-down mode, the charging unit 80 charges the battery BAT, and the battery BAT is in a charged state. When the mode switching circuit operates in the inverter mode, the battery BAT is discharged, and at this time, the inverter unit 60 is controlled to operate, so that the direct current output from the battery BAT is converted into alternating current through the inverter unit 60 and the transformer 50, and is transmitted to the alternating current output terminal 100. Wherein the capacitor C is used for filtering.

As shown in fig. 2, the inverter unit 60 includes a first switching tube G1, a second switching tube G2, a third switching tube G3, and a fourth switching tube G4. The first conduction end of the first switch tube G1 is electrically connected to the first conduction end of the second switch tube G2 and the battery unit 70, respectively, and the second conduction end of the first switch tube G1 is electrically connected to the first conduction end of the third switch tube G3 and the secondary winding of the transformer 50, respectively. The second conduction end of the second switching tube G2 is electrically connected to the first conduction end of the fourth switching tube G4 and the secondary winding of the transformer 50, respectively. The second conduction terminal of the third switching tube G3 is electrically connected to the second conduction terminal of the fourth switching tube G4 and the battery unit 70.

Specifically, as can be seen from fig. 2, the first conduction terminal of the first switching tube G1 is electrically connected to the first conduction terminal of the second switching tube G2, the first terminal of the capacitor C in the battery unit 70, and the positive electrode of the battery BAT, respectively. The second conduction terminal of the first switching tube G1 is electrically connected to the first conduction terminal of the third switching tube G3 and the third connection terminal 53 of the secondary winding of the transformer 50. The second conduction end of the second switching tube G2 is electrically connected to the first conduction end of the fourth switching tube G4 and the fourth connection end 54 of the secondary winding of the transformer 50. The second conducting end of the third switching tube G3 is electrically connected to the second conducting end of the fourth switching tube G4, the second end of the capacitor C in the battery unit 70, and the negative electrode of the battery BAT, respectively.

When the battery BAT is discharged, the first switching tube G1 and the fourth switching tube G4 are turned on, the second switching tube G2 and the third switching tube G3 are turned off, and then the current is output from the positive electrode of the battery BAT, and flows back to the negative electrode of the battery BAT through the first switching tube G1, the secondary winding of the transformer 50 and the fourth switching tube G4. When the first switching tube G1 and the fourth switching tube G4 are turned off and the second switching tube G2 and the third switching tube G3 are turned on, the current is output from the positive electrode of the battery BAT, and flows back to the negative electrode of the battery BAT through the second switching tube G2, the secondary winding of the transformer 50, and the third switching tube G3. At this time, a positive and negative alternating square wave is formed on the secondary winding of the transformer 50, and alternating voltage is generated on the transformer 50 by alternately and repeatedly switching on and off two pairs of switching tubes.

Furthermore, the first switch tube G1, the second switch tube G2, the third switch tube G3 and the fourth switch tube G4 are all NMOS tubes. The first conduction end of the first switch tube G1 is a drain electrode of the NMOS tube, the second conduction end of the first switch tube G1 is a source electrode of the NMOS tube, and the control end of the first switch tube G1 is a gate electrode of the NMOS tube. The first conducting end of the second switch tube G2 is a drain electrode of the NMOS tube, the second conducting end of the second switch tube G2 is a source electrode of the NMOS tube, and the control end of the second switch tube G2 is a gate electrode of the NMOS tube. The first conducting end of the third switching tube G3 is the drain of the NMOS tube, the second conducting end of the third switching tube G3 is the source of the NMOS tube, and the control end of the third switching tube G3 is the gate of the NMOS tube. The first conducting end of the fourth switching tube G4 is a drain electrode of the NMOS tube, the second conducting end of the fourth switching tube G4 is a source electrode of the NMOS tube, and the control end of the fourth switching tube G4 is a grid electrode of the NMOS tube.

The control end of the first switch tube G1, the control end of the second switch tube G2, the control end of the third switch tube G3 and the control end of the fourth switch tube G4 are all electrically connected with the control circuit. The control circuit is used for controlling the on/off of the first switching tube G1, the second switching tube G2, the third switching tube G3 and the fourth switching tube G4 according to the voltage of the alternating current input end 90.

For clarity of the description of the present application, the operation of the mode switching circuit is described in detail below with reference to fig. 2:

when the voltage of the ac input terminal 90 is within the predetermined range, the mode switching circuit operates in the normal mode. At this time, the second switching unit 20 is controlled to be turned off, so that the first terminal 21 of the second relay is disconnected from the third terminal 23 of the second relay, and the second terminal 22 of the second relay is disconnected from the fourth terminal 24 of the second relay. The third switching unit 30 is controlled to be turned off, and the first terminal 31 of the third relay is connected to the third terminal 33 of the third relay. The fourth switching unit 40 is controlled to be turned off, and the first terminal 41 of the fourth relay is connected to the third terminal 43 of the fourth relay. When the first switching unit 10 is controlled to be turned on, the first end 11 of the first relay is connected to the third end 13 of the first relay, the second end 12 of the first relay is connected to the fourth end 14 of the first relay, so that the first terminal L of the ac input terminal 90 is electrically connected to the first terminal L 'of the ac output terminal 100 through the first end 11 of the first relay and the third end 13 of the first relay, and the second terminal N of the ac input terminal 90 is electrically connected to the second terminal N' of the ac output terminal 100 through the second end 12 of the first relay and the fourth end 14 of the first relay. Therefore, the voltage at the ac input terminal 90 is directly transmitted to the ac output terminal 100 through the first switch unit 10 without passing through the transformer 50, thereby avoiding the loss caused by the transformer 50, improving the efficiency of the ups, and achieving the purpose of saving energy. The charging unit 80 is used to charge the battery BAT at this time. The application provides a mode switching circuit has solved the problem that off-line uninterrupted power source efficiency is low when mains voltage is in normal range.

When the voltage of the ac input terminal 90 is lower than the predetermined range and greater than the first threshold voltage, the mode switching circuit operates in the boost mode. When the second switching unit 20 is controlled to be turned on, the first end 21 of the second relay is connected to the third end 23 of the second relay, the second end 22 of the second relay is connected to the fourth end 24 of the second relay, so that the first terminal L of the ac input terminal 90 is electrically connected to the first tap 55 of the primary winding of the transformer 50 through the first end 21 of the second relay and the third end 23 of the second relay, and the second terminal N of the ac input terminal 90 is electrically connected to the second terminal N' of the ac output terminal 100 through the second end 22 of the second relay and the fourth end 24 of the second relay. When the first switch unit 10 is controlled to be turned off, the first terminal 11 of the first relay is disconnected from the third terminal 13 of the first relay, and the second terminal 12 of the first relay is disconnected from the fourth terminal 14 of the first relay. The third switching unit 30 is controlled to be turned on, and the first terminal 31 of the third relay is connected to the second terminal 32 of the third relay. And controlling the fourth switching unit 40 to be turned on, the first terminal 41 of the fourth relay is connected to the second terminal 42 of the fourth relay. The first connection terminal 51 of the primary winding of the transformer 50 is electrically connected to the first terminal L' of the ac output terminal 100 through the second terminal 42 of the fourth relay, the first terminal 41 of the fourth relay, the first terminal 31 of the third relay, and the second terminal 32 of the third relay. The voltage at the ac input terminal 90 is boosted by the self-coupling principle of the winding between the first tap 55 and the second connection terminal 52 of the primary winding of the transformer 50 and the winding between the first connection terminal 51 and the second connection terminal 52 of the primary winding of the transformer 50, and is transmitted to the ac output terminal 100. The charging unit 80 is used to charge the battery BAT. When the voltage of the ac input terminal 90 is low, the mode switching circuit provided in the embodiment of the present application can boost the voltage of the ac input terminal 90, thereby ensuring the normal operation of the uninterruptible power supply.

When the voltage of the ac input terminal 90 is higher than the predetermined range and lower than the second threshold voltage, the mode switching circuit operates in the buck mode. When the second switching unit 20 is controlled to be turned on, the first end 21 of the second relay is connected to the third end 23 of the second relay, the second end 22 of the second relay is connected to the fourth end 24 of the second relay, so that the first terminal L of the ac input terminal 90 is electrically connected to the first tap 55 of the primary winding of the transformer 50 through the first end 21 of the second relay and the third end 23 of the second relay, and the second terminal N of the ac input terminal 90 is electrically connected to the second terminal N' of the ac output terminal 100 through the second end 22 of the second relay and the fourth end 24 of the second relay. When the first switch unit 10 is controlled to be turned off, the first terminal 11 of the first relay is disconnected from the third terminal 13 of the first relay, and the second terminal 12 of the first relay is disconnected from the fourth terminal 14 of the first relay. The third switching unit 30 is controlled to be turned on, and the first terminal 31 of the third relay is connected to the second terminal 32 of the third relay. The fourth switching unit 40 is controlled to be turned off, and the first terminal 41 of the fourth relay is connected to the third terminal 43 of the fourth relay. The second tap 56 of the primary winding of the transformer 50 is electrically connected to the first terminal L' of the ac output terminal 100 through the third terminal 43 of the fourth relay, the first terminal 41 of the fourth relay, the first terminal 31 of the third relay, and the second terminal 32 of the third relay. The voltage at the ac input terminal 90 is reduced by the self-coupling principle of the winding between the first tap 55 and the second connection terminal 52 of the primary winding of the transformer 50 and the winding between the second tap 56 and the second connection terminal 52 of the primary winding of the transformer 50, and is delivered to the ac output terminal 100. The charging unit 80 is used to charge the battery BAT. When the voltage of the ac input terminal 90 is high, the mode switching circuit provided in the embodiment of the present application can step down the voltage of the ac input terminal 90, thereby ensuring the normal operation of the ups.

When the voltage at the ac input terminal 90 is greater than the second threshold voltage or less than the first threshold voltage, the mode switching circuit operates in the inverter mode. When the first switch unit 10 is controlled to be turned off, the first terminal 11 of the first relay is disconnected from the third terminal 13 of the first relay, and the second terminal 12 of the first relay is disconnected from the fourth terminal 14 of the first relay. When the second switch unit 20 is controlled to be turned off, the first terminal 21 of the second relay is disconnected from the third terminal 23 of the second relay, and the second terminal 22 of the second relay is disconnected from the fourth terminal 24 of the second relay. The third switching unit 30 is controlled to be turned on, and the first terminal 31 of the third relay is connected to the second terminal 32 of the third relay. The fourth switching unit 40 is controlled to be turned off, and the first terminal 41 of the fourth relay is connected to the third terminal 43 of the fourth relay. The second tap 56 of the primary winding of the transformer 50 is electrically connected to the first terminal L' of the ac output terminal 100 through the third terminal 43 of the fourth relay, the first terminal 41 of the fourth relay, the first terminal 31 of the third relay, and the second terminal 32 of the third relay. At this time, the battery BAT discharges to control the operation of the inverter unit 60, so that the two pairs of switching tubes in the inverter unit 60 are alternately turned on and off, thereby generating an ac voltage on the transformer 50 and transmitting the ac voltage to the ac output terminal 100. When the voltage at the ac input terminal 90 is abnormal, the mode switching circuit provided in the embodiment of the present application discharges electricity by using the battery unit 70, converts the dc power into the ac power through the inverter unit 60 and the transformer 50, and transmits the ac power to the ac output terminal 100, thereby ensuring the normal operation of the ups.

Note that the charging unit 80 is implemented by a conventional method.

As shown in fig. 3, an embodiment of the present application further provides an uninterruptible power supply 300, which includes a detection circuit 302, a control circuit 303, and the above-mentioned mode switching circuit 301. The mode switching circuit 301 is connected between the ac input terminal 90 and the ac output terminal 100. The detection circuit 302 is electrically connected to the first terminal L and the second terminal N of the ac input terminal 90. The control circuit 303 is electrically connected to the mode switching circuit 301 and the detection circuit 302, respectively.

Specifically, the control circuit 303 is electrically connected to the first switch unit, the second switch unit, the third switch unit, the fourth switch unit, and the inverter unit in the mode switching circuit 301.

The detection circuit 302 is configured to detect a voltage at the ac input terminal 90 and transmit the detected voltage to the control circuit 303.

When the voltage at the ac input terminal 90 is within the predetermined range, the mode switching circuit 301 operates in the normal mode. The control circuit 303 controls the first switching unit in the mode switching circuit 301 to be turned on, and the second switching unit, the third switching unit, and the fourth switching unit to be turned off. The voltage at the ac input terminal 90 is directly transmitted to the ac output terminal 100 through the first switch unit in the mode switching circuit 301 without passing through the transformer in the mode switching circuit 301, so that the loss caused by the transformer is avoided, the efficiency of the uninterruptible power supply is improved, and the purpose of energy saving is achieved. The utility model provides an uninterrupted power source has solved the problem that off-line uninterrupted power source efficiency is low when mains voltage is in normal range.

When the voltage of the ac input terminal 90 is lower than the predetermined range and greater than the first threshold voltage, the mode switching circuit 301 operates in the boost mode. The control circuit 303 controls the first switching unit in the mode switching circuit 301 to be turned off, and the second switching unit, the third switching unit and the fourth switching unit to be turned on. The voltage at the ac input terminal 90 is boosted by the primary side boost winding of the transformer in the mode switching circuit 301 and is transmitted to the ac output terminal 100. When the voltage of the ac input terminal 90 is low, the ups provided in the embodiment of the present application can boost the voltage of the ac input terminal 90, thereby ensuring the normal operation of the ups.

When the voltage of the ac input terminal 90 is higher than the predetermined range and lower than the second threshold voltage, the mode switching circuit 301 operates in the buck mode. The control circuit 303 controls the first switching unit and the fourth switching unit in the mode switching circuit 301 to be turned off, and the second switching unit and the third switching unit to be turned on. The voltage at the ac input terminal 90 is reduced by the primary voltage reduction winding of the transformer in the mode switching circuit 301 and is transmitted to the ac output terminal 100. When the voltage of the ac input terminal 90 is higher, the uninterruptible power supply provided in the embodiment of the present application can step down the voltage of the ac input terminal 90, thereby ensuring the normal operation of the uninterruptible power supply.

When the voltage at the ac input terminal 90 is greater than the second threshold voltage or less than the first threshold voltage, the mode switching circuit 301 operates in the inverter mode. The control circuit 303 controls the first, second, and fourth switching units in the mode switching circuit 301 to be turned off, and the third switching unit to be turned on. The battery unit in the mode switching circuit 301 discharges, the control circuit 303 controls two pairs of switching tubes in the inverter unit in the mode switching circuit 301 to be alternately turned on and off, and the transformer in the mode switching circuit 301 generates an ac voltage and transmits the ac voltage to the ac output terminal 100. When the voltage at the ac input terminal 90 is abnormal, the uninterruptible power supply provided in the embodiment of the present application discharges by using the battery unit in the mode switching circuit, converts the dc power into the ac power through the inverter unit and the transformer, and transmits the ac power to the ac output terminal 100, thereby ensuring the normal operation of the uninterruptible power supply.

To sum up, the uninterruptible power supply provided by the embodiment of the application has the advantages of high efficiency and energy conservation, and solves the problem of low efficiency of the offline uninterruptible power supply in a normal range of the mains voltage.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims (10)

1. A mode switching circuit is characterized by comprising a first switch unit, a second switch unit, a third switch unit, a fourth switch unit, a transformer, an inverter unit, a charging unit and a battery unit;

the charging unit is electrically connected with the battery unit, the battery unit is electrically connected with the inversion unit, the inversion unit is electrically connected with a secondary winding of the transformer, a primary winding of the transformer is respectively electrically connected with the fourth switch unit and the second switch unit, the fourth switch unit is electrically connected with the third switch unit, the first switch unit, the second switch unit and the charging unit are all used for being electrically connected with a first terminal and a second terminal of an alternating current input end, the third switch unit and the first switch unit are all used for being electrically connected with a first terminal of an alternating current output end, and the primary winding of the transformer, the first switch unit and the second switch unit are all used for being electrically connected with a second terminal of the alternating current output end.

2. The mode switching circuit of claim 1, wherein the primary winding of the transformer includes a first connection terminal, a second connection terminal, a first tap, and a second tap;

the first connecting end and the second tap of the primary winding of the transformer are electrically connected with the fourth switching unit, the first tap of the primary winding of the transformer is electrically connected with the second switching unit, and the second connecting end of the primary winding of the transformer is used for being electrically connected with the second terminal of the alternating current output end;

the secondary winding of the transformer comprises a third connection terminal and a fourth connection terminal; and the third connecting end and the fourth connecting end of the secondary winding of the transformer are electrically connected with the inverter unit.

3. The mode switching circuit according to claim 1, wherein the first switching unit includes a first relay; the first end of the first relay is used for being electrically connected with the first terminal of the alternating current input end, the second end of the first relay is used for being electrically connected with the second terminal of the alternating current input end, the third end of the first relay is used for being electrically connected with the first terminal of the alternating current output end, and the fourth end of the first relay is used for being electrically connected with the second terminal of the alternating current output end.

4. The mode switching circuit according to claim 1, wherein the second switching unit includes a second relay; the first end of the second relay is used for being electrically connected with the first terminal of the alternating current input end, the second end of the second relay is used for being electrically connected with the second terminal of the alternating current input end, the third end of the second relay is electrically connected with the primary winding of the transformer, and the fourth end of the second relay is used for being electrically connected with the second terminal of the alternating current output end.

5. The mode switching circuit according to claim 1, wherein the third switching unit includes a third relay; and the first end of the third relay is electrically connected with the fourth switch unit, and the second end of the third relay is electrically connected with the first terminal of the alternating current output end.

6. The mode switching circuit of claim 1, wherein the fourth switching unit comprises a fourth relay; the first end of the fourth relay is electrically connected with the third switch unit, and the second end of the fourth relay and the third end of the fourth relay are both electrically connected with the primary winding of the transformer.

7. The mode switching circuit of claim 1, wherein the battery cell comprises a battery and a capacitor; the positive electrode of the battery is electrically connected with the charging unit, the first end of the capacitor and the inversion unit respectively, and the negative electrode of the battery is electrically connected with the charging unit, the second end of the capacitor and the inversion unit respectively.

8. The mode switching circuit according to claim 1, wherein the inverter unit comprises a first switching tube, a second switching tube, a third switching tube and a fourth switching tube;

the first end that switches on of first switch tube respectively with the first end that switches on of second switch tube with the battery unit electricity is connected, the second of first switch tube switch on the end respectively with the first end that switches on of third switch tube with the secondary winding electricity of transformer is connected, the second of second switch tube switch on the end respectively with the first end that switches on of fourth switch tube with the secondary winding electricity of transformer is connected, the second of third switch tube switch on the end respectively with the second end that switches on of fourth switch tube with the battery unit electricity is connected.

9. The mode switching circuit of claim 8, wherein the first switch tube, the second switch tube, the third switch tube and the fourth switch Guan Junwei NMOS tube.

10. An uninterruptible power supply comprising the mode switching circuit of any of claims 1 to 9.

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