Multi-resonance circuit, UPS cold start circuit and UPS power supply system

Abstract

A multi-resonance circuit, a UPS cold start circuit and a UPS power supply system belong to the field of electronic technology. The first end of a first inductor, the first end of a second resistor, the first end of a third resistor, the emitter of a first triode and the emitter of a second triode are connected to a battery voltage; the second end of the first inductor is connected to a primary center tap of a transformer, the collector of the first triode is connected to a first end of a second capacitor and a primary first end of the transformer, the second end of the second capacitor is connected to a primary second end of the transformer and a collector of the second triode, the second end of the second resistor is connected to a base of the first triode and a first end of an auxiliary winding of the transformer, the second end of the third resistor is connected to a base of the second triode and a second end of an auxiliary winding of the transformer, the first end of a secondary side of the transformer, the second end of a secondary side of the transformer and the secondary center tap of the transformer output driving alternating current, and at the same time, isolation of dry node signals and long-distance power supply are realized.

Description

Technical Field

[0001] The present application belongs to the field of electronic technology, and in particular relates to a multi-resonance circuit, a UPS cold start circuit and a UPS power supply system. Background Art

[0002] Using energy storage modules to supply power when the city power is interrupted is a common way of uninterruptible power supply (UPS). However, the output power of the energy storage module is a DC power supply, which cannot meet the needs of AC equipment. It needs to be boosted, inverted, and filtered by the internal circuit before outputting AC power to the AC equipment. In the prior art, the UPS needs to be connected to AC power before it can start the output normally. When there is no AC power input to the UPS, the UPS battery cold start device needs to be started by the battery. After starting, it will be powered by the battery pack for a period of time. At present, the cold start device of UPS generally adopts the battery voltage series resistor voltage division, and the voltage regulator diode is used as the power supply of the cold start device signal. After manually pressing the cold start switch, the internal cold start circuit of the UPS is connected. Figure 1 As shown, the UPS internal high-voltage bus is connected for charging. After the bus voltage rises to the system power operating point, the UPS system power starts to work, and then the controller controls the battery boost circuit to continuously supply power to the bus. Although the principle of the current cold start device is simple, the disadvantage is that the signal power supply of the existing cold start device is not electrically isolated from the battery and the internal high-voltage circuit of the UPS, and the dry node cold start function cannot be realized.

[0003] Therefore, the related UPS cold start circuit cannot meet the isolation requirements of dry node signals and the long-distance power supply requirements at the same time. Summary of the invention

[0004] The purpose of the present application is to provide a multi-resonance circuit, a UPS cold start circuit and a UPS power supply system, aiming to solve the problem that the existing cold start circuit cannot simultaneously meet the isolation requirements of dry node signals and the long-distance power supply requirements.

[0005] The embodiment of the present application provides a multi-resonance circuit, including a transformer, a first inductor, a first transistor, a second transistor, a second resistor, a third resistor and a second capacitor;

[0006] The first end of the first inductor, the first end of the second resistor, the first end of the third resistor, the emitter of the first transistor and the emitter of the second transistor are collectively used as the battery voltage input end of the multi-resonance circuit to access the battery voltage; the second end of the first inductor is connected to the center tap of the primary side of the transformer, the collector of the first transistor is connected to the first end of the second capacitor and the first end of the primary side of the transformer, the second end of the second capacitor is connected to the second end of the primary side of the transformer and the collector of the second transistor, the second end of the second resistor is connected to the base of the first transistor and the first end of the auxiliary winding of the transformer, the second end of the third resistor is connected to the base of the second transistor and the second end of the auxiliary winding of the transformer, and the first end of the secondary side of the transformer and the second end of the secondary side of the transformer are collectively used as the driving AC output end of the multi-resonance circuit to output driving AC.

[0007] In one of the embodiments, a second transient voltage suppression diode and a third transient voltage suppression diode are further included;

[0008] The anode of the second transient voltage suppression diode is connected to the emitter of the first transistor, the emitter of the second transistor and the anode of the third transient voltage suppression diode, the cathode of the second transient voltage suppression diode is connected to the collector of the first transistor, the first end of the second capacitor and the first end of the primary side of the transformer, and the cathode of the third transient voltage suppression diode is connected to the second end of the second capacitor, the second end of the primary side of the transformer and the collector of the second transistor.

[0009] In one embodiment, it also includes:

[0010] An input voltage stabilizing and current limiting circuit, configured to stabilize and limit the current of the battery voltage;

[0011] The input filtering circuit is connected to the input voltage stabilizing and current limiting circuit and is configured to filter the battery voltage after voltage stabilization and current limiting.

[0012] The embodiment of the present application also provides a UPS cold start circuit, connected between a bus bar and a dry contact, including a dry contact interface circuit, a switch circuit and the above-mentioned multi-resonance circuit;

[0013] The dry contact interface circuit is connected to the multi-resonance circuit and is configured to output a switch signal according to the connectivity of the dry contact and the driving DC power;

[0014] The switch circuit is connected to the bus bar and the dry contact interface circuit, and is configured to transmit the battery voltage to the bus bar according to the switch signal.

[0015] In one embodiment, it also includes:

[0016] an input protection circuit, connected to the multi-resonance circuit and the switch circuit, and configured to unidirectionally conduct the battery voltage;

[0017] The switch circuit is specifically configured to transmit the battery voltage after unidirectional conduction to the bus according to the switch signal.

[0018] In one embodiment, it also includes:

[0019] A step-down circuit, connected to the input protection circuit, the multi-resonance circuit and the dry contact interface circuit, configured to step down the battery voltage after unidirectional conduction;

[0020] The dry contact interface circuit is specifically configured to output the switch signal according to the stepped-down battery voltage, the connectivity of the dry contact, and the driving direct current.

[0021] In one of the embodiments, the dry contact interface circuit includes a photocoupler and a fifth resistor;

[0022] The collector of the photoelectric coupler serves as the battery voltage input terminal of the dry contact interface circuit to input the battery voltage; the emitter of the photoelectric coupler serves as the switch signal output terminal of the dry contact interface circuit and is connected to the switch circuit to output the switch signal; the positive electrode of the photoelectric coupler is connected to the first end of the fifth resistor, and the second end of the fifth resistor serves as the driving DC input terminal of the dry contact interface circuit and is connected to the multi-resonance circuit to input the driving DC; the negative electrode of the photoelectric coupler is connected to the dry contact.

[0023] In one embodiment, the switch circuit includes a relay, an NMOS, a seventh diode, a sixth resistor, and a seventh resistor;

[0024] The first common end of the relay, the first end of the sixth resistor, the second common end of the relay, the source of the NMOS and the first end of the seventh resistor are used together as the battery voltage input end of the switch circuit to input the battery voltage; the second end of the sixth resistor is connected to the cathode of the seventh diode and the first end of the coil of the relay, the second end of the coil of the relay is connected to the drain of the NMOS and the anode of the seventh diode, the gate of the NMOS and the second end of the seventh resistor are used as the switch signal input end of the switch circuit, and are connected to the dry contact interface circuit to input the switch signal; the first normally open contact of the relay and the second normally open contact of the relay are used together as the battery voltage output end of the switch circuit to output the battery voltage.

[0025] An embodiment of the present application also provides a UPS power system, including the above-mentioned UPS cold start circuit.

[0026] In one embodiment, the UPS power supply system further includes:

[0027] A battery charging and discharging circuit, connected to the DC bus circuit and the UPS cold start circuit, configured to access the battery voltage, convert the battery voltage into a first voltage, or convert the DC power into a charging voltage to charge the energy storage module;

[0028] A PFC circuit configured to rectify input AC power to output the DC power;

[0029] a DC bus circuit, connected to the PFC circuit, and configured to filter the DC power or the first voltage to output a second voltage;

[0030] an inverter circuit connected to the DC bus circuit and configured to invert the second voltage to output an output AC power to an output interface;

[0031] a DC converter circuit, connected to the DC bus circuit, and configured to convert the second voltage into an auxiliary voltage to power various functional modules;

[0032] The bypass circuit is configured to transmit the input AC power to the output interface in response to a bypass control signal.

[0033] Compared with the prior art, the embodiments of the present application have the following beneficial effects: the first end of the first inductor, the first end of the second resistor, the first end of the third resistor, the emitter of the first transistor and the emitter of the second transistor are used together as the battery voltage input end of the multi-resonance circuit to access the battery voltage; the second end of the first inductor is connected to the primary center tap of the transformer, the collector of the first transistor is connected to the first end of the second capacitor and the primary first end of the transformer, the second end of the second capacitor is connected to the primary second end of the transformer and the collector of the second transistor, the second end of the second resistor is connected to the base of the first transistor and the first end of the auxiliary winding of the transformer, the second end of the third resistor is connected to the base of the second transistor and the second end of the auxiliary winding of the transformer, the first end of the secondary side of the transformer, the second end of the secondary side of the transformer and the secondary center tap of the transformer are used together as the driving AC output end of the multi-resonance circuit to output driving AC, and the driving AC is output by the isolated current source composed of the transformer, which can not only meet the isolation requirements of the dry node signal, but also realize long-distance power supply of the dry node signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical application in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 A schematic diagram of the circuit for realizing the cold start device of a traditional UPS;

[0036] Figure 2 An exemplary circuit schematic diagram of a multi-resonance circuit provided in an embodiment of the present application;

[0037] Figure 3 Another partial exemplary circuit structure diagram of a multi-resonance circuit provided in an embodiment of the present application;

[0038] Figure 4 Another partial exemplary circuit structure diagram of a multi-resonance circuit provided in an embodiment of the present application;

[0039] Figure 5 A partial exemplary circuit structure diagram of a UPS cold start circuit provided in one embodiment of the present application;

[0040] Figure 6 Another partial exemplary circuit structure diagram of a UPS cold start circuit provided in an embodiment of the present application;

[0041] Figure 7 Another partial exemplary circuit structure diagram of a UPS cold start circuit provided in an embodiment of the present application;

[0042] Figure 8 Another partial exemplary circuit structure diagram of a UPS cold start circuit provided in an embodiment of the present application;

[0043] Fig. 9 Another partial exemplary circuit structure diagram of a UPS cold start circuit provided in an embodiment of the present application;

[0044] Fig.10 A partial exemplary circuit schematic diagram of a UPS cold start circuit provided in one embodiment of the present application;

[0045] Fig.11 Another partial exemplary circuit schematic diagram of a UPS cold start circuit provided in an embodiment of the present application;

[0046] Fig.12 A partial exemplary circuit structure diagram of a UPS power system provided in one embodiment of the present application. DETAILED DESCRIPTION

[0047] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0048] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0049] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0050] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0051] Figure 2 The structure diagram of the multi-resonance circuit 100 provided in one embodiment of the present application is shown. For the convenience of description, only the part related to the present embodiment is shown, which is described in detail as follows:

[0052] The multi-resonance circuit 100 includes a transformer T1 , a first inductor L1 , a first transistor Q1 , a second transistor Q2 , a second resistor R2 , a third resistor R3 , and a second capacitor C2 .

[0053] The first end of the first inductor L1, the first end of the second resistor R2, the first end of the third resistor R3, the emitter of the first transistor Q1 and the emitter of the second transistor Q2 are commonly used as the battery voltage input end of the multi-resonance circuit 100 to access the battery voltage; the second end of the first inductor L1 is connected to the center tap of the primary side of the transformer T1, the collector of the first transistor Q1 is connected to the first end of the second capacitor C2 and the first end of the primary side of the transformer T1, the second end of the second capacitor C2 is connected to the second end of the primary side of the transformer T1 and the collector of the second transistor Q2, the second end of the second resistor R2 is connected to the base of the first transistor Q1 and the first end of the auxiliary winding of the transformer T1, the second end of the third resistor R3 is connected to the base of the second transistor Q2 and the second end of the auxiliary winding of the transformer T1, the first end of the secondary side of the transformer T1 and the second end of the secondary side of the transformer T1 are commonly used as the driving AC output end of the multi-resonance circuit 100 to output the driving AC.

[0054] It should be noted that if Fig.10 As shown, the secondary side of the transformer T1 may have a center tap; in this case, the first end of the secondary side of the transformer T1, the second end of the secondary side of the transformer T1 and the center tap of the secondary side of the transformer T1 are used together as the driving AC output end of the multi-resonance circuit 100 to output the driving AC, such as Fig.11 The secondary side of the transformer T1 may not have a center tap; this application does not specifically limit whether the secondary side of the transformer T1 actually used has a center tap.

[0055] The driving alternating current is outputted through the transformer T1, the first inductor L1, the first transistor Q1, the second transistor Q2, the second resistor R2, the third resistor R3 and the second capacitor C2. There is no need to use a special power controller chip and a logic chip. Only discrete devices are used to realize an isolated current source, which has low cost and can meet the isolation requirements of dry node signals. The cold start function of the UPS power system is remotely intelligently triggered. There is no need to start the cold start function of the UPS power system by pressing a button on the cabinet, and the reliability is high.

[0056] The multi-resonance circuit 100 mentioned above mainly provides a 2mA current source for the dry node module, with low power consumption at the mW level, and can meet the long-distance power supply requirements of the dry node signal.

[0057] By way of example and not limitation, Fig.10 and Fig.11 As shown, the multi-resonance circuit 100 further includes a second transient voltage suppression diode Z2 and a third transient voltage suppression diode Z3.

[0058] The anode of the second transient voltage suppression diode Z2 is connected to the emitter of the first transistor Q1, the emitter of the second transistor Q2 and the anode of the third transient voltage suppression diode Z3, the cathode of the second transient voltage suppression diode Z2 is connected to the collector of the first transistor Q1, the first end of the second capacitor C2 and the primary first end of the transformer T1, and the cathode of the third transient voltage suppression diode Z3 is connected to the second end of the second capacitor C2, the primary second end of the transformer T1 and the collector of the second transistor Q2.

[0059] The second transient voltage suppression diode Z2 and the third transient voltage suppression diode Z3 are used to protect the first transistor Q1 and the second transistor Q2, thereby avoiding overvoltage damage to the transistors and improving the safety of the circuit.

[0060] By way of example and not limitation, Figure 4 As shown, the multi-resonance circuit 100 further includes an input voltage stabilizing and current limiting circuit 110 and an input filtering circuit 120 .

[0061] The input voltage stabilizing and current limiting circuit 110 is configured to stabilize the battery voltage and limit the current.

[0062] The input filtering circuit 120 is connected to the input voltage stabilizing and current limiting circuit 110 and is configured to filter the battery voltage after voltage stabilization and current limiting.

[0063] The output of the secondary side of the transformer T1 is open-loop coupled with the primary side, which is equivalent to a current transformer. Since the input current of the primary side is limited by the input voltage stabilizing and current limiting circuit 110, the current output by the multi-resonance circuit 100 is also limited within a certain range.

[0064] In the input voltage stabilizing and current limiting circuit 110 , a transient voltage suppressor diode or a varistor may be used for voltage stabilization.

[0065] The input voltage stabilizing and current limiting circuit 110 ensures that the output current is within a preset range, thereby preventing damage to the subsequent circuit caused by excessive output current, and improving the reliability of the circuit.

[0066] By way of example and not limitation, Figure 4 As shown, the multi-resonance circuit 100 further includes a rectifier circuit 130 , an input filter circuit 120 and an output voltage stabilizing and current limiting circuit 150 .

[0067] The rectifier circuit 130 is configured to rectify the driving alternating current to output a driving direct current.

[0068] The output filter circuit 140 is connected to the rectifier circuit 130 and is configured to filter the driving direct current.

[0069] The output voltage stabilizing and current limiting circuit 150 is connected to the output filtering circuit 140 and is configured to stabilize the voltage and limit the current of the filtered driving direct current.

[0070] The driving alternating current is rectified into driving direct current by the rectifying circuit 130, thereby improving the adaptability of the circuit.

[0071] Fig.10 FIG. 1 shows a partial exemplary circuit structure of a multi-resonance circuit 100 provided in an embodiment of the present application. Fig.11 Another partial exemplary circuit structure of the multi-resonance circuit 100 provided in an embodiment of the present application is shown. For the sake of convenience, only the part related to the embodiment of the present application is shown, which is described in detail as follows:

[0072] like Fig.10 and Fig.11 As shown, the input voltage stabilizing and current limiting circuit 110 includes a first resistor R1 and a first transient voltage suppression diode Z1.

[0073] The first end of the first resistor R1 and the positive electrode of the first transient voltage suppression diode Z1 serve together as the battery voltage input end of the input voltage stabilization and current limiting circuit 110, and are connected to the input protection circuit 400 to access the battery voltage; the second end of the first resistor R1, the negative electrode of the first transient voltage suppression diode Z1 and the positive electrode of the first transient voltage suppression diode Z1 serve together as the battery voltage output end after voltage stabilization and current limiting of the input voltage stabilization and current limiting circuit 110, and are connected to the input filter circuit 120 to output the battery voltage after voltage stabilization and current limiting.

[0074] like Fig.10 and Fig.11 As shown, the input filter circuit 120 includes a first capacitor C1.

[0075] The first end of the first capacitor C1 and the second end of the first capacitor C1 serve together as the stabilized and current-limited battery voltage input end of the input filter circuit 120 and the filtered battery voltage output end of the filter circuit to input the stabilized and current-limited battery voltage and output the filtered battery voltage.

[0076] like Fig.10 As shown, the rectifier circuit 130 includes a fifth diode D5 and a sixth diode D6.

[0077] The anode of the fifth diode D5 is connected to the first end of the secondary side of the transformer T1, and the anode of the sixth diode D6 is connected to the second end of the secondary side of the transformer T1. The anode of the fifth diode D5 and the anode of the sixth diode D6 serve together as the driving AC input terminal of the rectifier circuit 130 to input driving AC power; the cathode of the fifth diode D5 and the cathode of the sixth diode D6 serve together as the driving DC output terminal of the rectifier circuit 130, and are connected to the output filter circuit 140 to output driving DC power.

[0078] like Fig.11 As shown, the rectifier circuit 130 includes a fifth diode D5.

[0079] The anode of the fifth diode D5 serves as the driving AC input terminal of the rectifier circuit 130, and is connected to the first end of the secondary side of the transformer T1 to input the driving AC power; the cathode of the fifth diode D5 serves as the driving DC output terminal of the rectifier circuit 130, and is connected to the output filter circuit 140 to output the driving DC power.

[0080] like Fig.10 and Fig.11 As shown, the output filter circuit 140 includes a second inductor L2 and a third capacitor C3.

[0081] The first end of the second inductor L2 and the first end of the third capacitor C3 serve together as the input end of the driving DC power, and are connected to the rectifier circuit 130 to input the driving DC power; the second end of the second inductor L2 and the first end of the third capacitor C3 and the second end of the third capacitor C3 serve together as the output end of the filtered driving DC power, and are connected to the output voltage stabilizing and current limiting circuit 150 to output the filtered driving DC power.

[0082] like Fig.10 and Fig.11 As shown, the output voltage stabilizing and current limiting circuit 150 includes a fourth transient voltage suppression diode Z4 and a fourth resistor R4.

[0083] The anode of the fourth transient voltage suppression diode Z4, the cathode of the fourth transient voltage suppression diode Z4 and the first end of the fourth resistor R4 are used together as the filtered driving DC input terminal of the output voltage stabilization and current limiting circuit 150, and are connected to the output filter circuit 140 to input the filtered driving DC; the anode of the fourth transient voltage suppression diode Z4 and the second end of the fourth resistor R4 are used together as the stabilized and current-limited driving DC output terminal of the output voltage stabilization and current limiting circuit 150 to output the stabilized and current-limited driving DC.

[0084] The following is a combination of working principles Figure 10 to Figure 11 The multi-resonance circuit 100 is shown for further explanation:

[0085] like Fig.10 and Fig.11As shown, the first end of the first resistor R1 and the positive electrode of the first transient voltage suppression diode Z1 are connected to the battery voltage, the first resistor R1 and the first transient voltage suppression diode Z1 stabilize and limit the battery voltage, and output the stabilized and current-limited battery voltage from the second end of the first resistor R1, the negative electrode of the first transient voltage suppression diode Z1 and the positive electrode of the first transient voltage suppression diode Z1 to the first capacitor C1, and the first capacitor C1 filters the stabilized and current-limited battery voltage and outputs it to the first end of the first inductor L1 and the first inductor L2. The first end of the second resistor R2, the first end of the third resistor R3, the emitter of the first transistor Q1 and the emitter of the second transistor Q2. It can be understood that since the performances of the first transistor Q1 and the second transistor Q2 cannot be absolutely consistent, at the moment when the transformer T1 is powered on, the collector current iq1 flowing through the first transistor Q1 and the collector current iq2 flowing through the second transistor Q2 cannot be completely the same. Therefore, the first transistor Q1 and the second transistor Q2 will not be turned on at the same time, and one of them must be turned on first.

[0086] Assume that iq1>iq2 at the moment when transformer T1 is connected to the power supply, then it can be known that the direction and size of the magnetic flux generated by transformer T1 are mainly determined by the rate of change of the collector current iq1 of the first transistor Q1. The change of magnetic flux causes the auxiliary winding to generate an induced electromotive force. From the flow direction of the collector current iq1 of the first transistor Q1, it can be known that the first end of the auxiliary winding is positive and the second end of the auxiliary winding is negative. It can be further known that the base potential of the second transistor Q2 is reduced, forming negative feedback to the second transistor Q2, making the collector current iq2 of the second transistor Q2 smaller and smaller; the base potential of the first transistor Q1 rises, forming positive feedback to the first transistor Q1, making the collector current iq1 of the first transistor Q1 larger and larger, and the magnetic flux of transformer T1 also increases accordingly. When the interaction of the change of magnetic flux and the induced electromotive force causes the first transistor Q1 to be saturated and turned on and the second transistor Q2 to be turned off, the magnetic flux reaches the maximum value. At this time, the induced electromotive force proportional to the rate of change of magnetic flux is zero.

[0087] Due to the disappearance of the induced electromotive force on the auxiliary winding, the base potential of the first transistor Q1 decreases, and iq1 also decreases. At this time, due to the reverse change rate of the collector current iq1 of the first transistor Q1, the magnetic flux is reversed, thereby causing the induced electromotive force of the auxiliary winding to reverse. At this time, the first end of the auxiliary winding is negative and the second end of the auxiliary winding is positive, thereby causing the base potential of the second transistor Q2 to rise and the base potential of the first transistor Q1 to decrease, thereby forming negative feedback for the first transistor Q1, making the collector current iq1 of the first transistor Q1 smaller and smaller; forming positive feedback for the second transistor Q2, making the collector current iq2 of the second transistor Q2 larger and larger, and the magnetic flux also increases. When the second transistor Q2 is saturated and turned on and the first transistor Q1 is turned off due to the change of magnetic flux and the interaction of the induced electromotive force, the magnetic flux reaches the maximum value. At this time, the induced electromotive force proportional to the rate of change of magnetic flux is zero.

[0088] The above two processes are continuously cycled, thereby forming oscillation on the secondary side of the transformer T1, and the existence of the resonant inductor L1 and the capacitor C2 makes the oscillation circuit perform simple harmonic oscillation at a specific frequency.

[0089] like Fig.10 As shown, the secondary output first end of the transformer T1, the secondary second end of the transformer T1 and the secondary center tap of the transformer T1 jointly output the driving alternating current to the positive electrode of the fifth diode D5 and the positive electrode of the sixth diode D6, the fifth diode D5 and the sixth diode D6 rectify the driving alternating current, and jointly output the driving direct current from the negative electrode of the fifth diode D5 and the negative electrode of the sixth diode D6 to the first end of the second inductor L2 and the first end of the third capacitor C3, the second inductor L2 and the third capacitor C3 filter the driving direct current, and output the filtered driving direct current from the second end of the second inductor L2, the first end of the third capacitor C3 and the second end of the third capacitor C3 to the positive electrode of the fourth transient voltage suppression diode Z4, the negative electrode of the fourth transient voltage suppression diode Z4 and the first end of the fourth resistor R4, the fourth transient voltage suppression diode Z4 and the fourth resistor R4 stabilize and limit the filtered driving direct current, and output the stabilized and limited driving direct current from the positive electrode of the fourth transient voltage suppression diode Z4 and the second end of the fourth resistor R4.

[0090] Fig.11 In the embodiment, the transformer T1 drives the AC power from the output first terminal of the transformer T1 to the positive electrode of the fifth diode D5 according to the oscillation, and the working principle of the rest of the circuit is the same as that of the Fig.10 The same as in, no further description is given here.

[0091] By way of example and not limitation, Figure 5As shown, the embodiment of the present application also provides a UPS cold start circuit 10, which is connected between the bus and the dry contact S1, and includes a dry contact S1 interface circuit 200, a switch circuit 300 and the above-mentioned multi-resonance circuit 100.

[0092] The dry contact S1 interface circuit 200 is connected to the multi-resonance circuit 100 and is configured to output a switch signal according to the connection of the dry contact S1 and the driving direct current.

[0093] The switch circuit 300 is connected to the bus bar and the dry contact S1 interface circuit 200 and is configured to transmit the battery voltage to the bus bar according to the switch signal.

[0094] After the dry contact S1 is connected, a closed loop is formed, and the dry contact S1 interface circuit 200 outputs a switching signal to the switching circuit 300. The switching circuit 300 transmits the battery voltage to the bus according to the switching signal. The bus is charged according to the battery voltage and supplies power to the UPS power system after a preset time, thereby realizing a cold start of the UPS power system.

[0095] By way of example and not limitation, Figure 6 As shown, the UPS cold start circuit 10 further includes an input protection circuit 400 .

[0096] The input protection circuit 400 is connected to the multi-resonance circuit 100 and the switch circuit 300 and is configured to conduct the battery voltage in a unidirectional manner.

[0097] The switch circuit 300 is specifically configured to transmit the unidirectionally conducted battery voltage to the bus according to the switch signal.

[0098] The input protection circuit 400 prevents the input battery voltage from damaging the circuit when the battery is reversely connected, thereby improving the safety of the circuit.

[0099] By way of example and not limitation, Figure 7 As shown, the UPS cold start circuit 10 further includes a voltage reduction circuit 500 .

[0100] The step-down circuit 500 is connected to the input protection circuit 400 , the multi-resonance circuit 100 and the dry contact S1 interface circuit 200 , and is configured to step down the voltage after unidirectional conduction.

[0101] The dry contact S1 interface circuit 200 is specifically configured to output a switch signal according to the stepped-down battery voltage, the connectivity of the dry contact S1 and the driving direct current.

[0102] The battery voltage is stepped down by the step-down circuit 500 and then input to the dry contact S1 interface circuit 200 , thereby avoiding damage to the dry contact S1 interface circuit 200 caused by excessive battery voltage, and improving the safety of the circuit.

[0103] By way of example and not limitation, Figure 8 As shown, the UPS cold start circuit 10 further includes an output protection circuit 600 .

[0104] The output protection circuit 600 is connected to the switch circuit 300 and is configured to unidirectionally conduct and limit the current of the battery voltage output by the switch circuit 300 .

[0105] The output protection circuit 600 avoids the damage to the subsequent circuit caused by the battery voltage when the battery is reversely connected, thereby improving the safety of the circuit.

[0106] By way of example and not limitation, Fig. 9 As shown, the dry contact S1 interface circuit 200 is specifically configured to output a switch signal according to the battery voltage after current and voltage limiting, the connectivity of the dry contact S1 and the driving current.

[0107] It should be noted that at this time, the dry contact S1 interface circuit 200 is connected to the input voltage stabilizing and current limiting circuit 110 in the multi-resonance circuit 100, so that a switching signal is output according to the battery voltage after current and voltage limiting, the connectivity of the dry contact S1, and the driving current. There is no need to add an additional buck circuit 500 for the power supply of the dry contact S1 interface circuit 200, which simplifies the circuit and saves costs.

[0108] Fig.10 A partial exemplary circuit structure of a UPS cold start circuit 10 provided in an embodiment of the present application is shown. Fig.11 Another partial exemplary circuit structure of the UPS cold start circuit 10 provided in the embodiment of the present application is shown. For the convenience of description, only the part related to the embodiment of the present application is shown, which is described in detail as follows:

[0109] like Fig.10 and Fig.11 As shown, the dry contact S1 interface circuit 200 includes a photocoupler PC1 and a fifth resistor R5.

[0110] The collector of the photocoupler PC1 serves as the battery voltage input terminal of the dry contact S1 interface circuit 200 to input the battery voltage; the emitter of the photocoupler PC1 serves as the switch signal output terminal of the dry contact S1 interface circuit 200 and is connected to the switch circuit 300 to output the switch signal; the positive electrode of the photocoupler PC1 is connected to the first end of the fifth resistor R5, and the second end of the fifth resistor R5 serves as the driving DC input terminal of the dry contact S1 interface circuit 200 and is connected to the multi-resonance circuit 100 to input the driving DC; the negative electrode of the photocoupler PC1 is connected to the dry contact S1.

[0111] The fifth resistor R5 limits the current of the driving DC power. Since the fourth resistor R4 also limits the current of the driving DC power, the fifth resistor R5 can also be omitted.

[0112] Isolation is performed through the photocoupler PC1 to avoid mutual interference between input and output signals and improve the stability of the circuit.

[0113] like Fig.10 and Fig.11 As shown, the switch circuit 300 includes a relay K1, an N-type metal oxide semiconductor (NMOS, negative channel metal oxide semiconductor) Q3, a seventh diode D7, a sixth resistor R6 and a seventh resistor R7.

[0114] The first common terminal of the relay K1, the first terminal of the sixth resistor R6, the second common terminal of the relay K1, the source of the NMOS Q3 and the first terminal of the seventh resistor R7 are used together as the battery voltage input terminal of the switch circuit 300 to input the battery voltage; the second terminal of the sixth resistor R6 is connected to the cathode of the seventh diode D7 and the first terminal of the coil of the relay K1, the second terminal of the coil of the relay K1 is connected to the drain of the NMOS Q3 and the anode of the seventh diode D7, the gate of the NMOS Q3 and the second terminal of the seventh resistor R7 are used as the switch signal input terminal of the switch circuit 300, and are connected to the dry contact S1 interface circuit 200 to input the switch signal; the first normally open contact of the relay K1 and the second normally open contact of the relay K1 are used together as the battery voltage output terminal of the switch circuit 300 to output the battery voltage.

[0115] It should be noted that the NMOS Q3 can be replaced by a triode.

[0116] Relay K1 acts as a switch with high reliability.

[0117] like Fig.10 and Fig.11 As shown, the input protection circuit 400 includes a first diode D1 and a second diode D2.

[0118] The anode of the first diode D1 and the cathode of the second diode D2 serve together as the battery voltage input terminal of the input protection circuit 400 to input the battery voltage; the cathode of the first diode D1 and the anode of the second diode D2 serve together as the battery voltage output terminal of the input protection circuit 400 after unidirectional conduction, and are connected to the multi-resonance circuit 100 and the switch circuit 300 to output the battery voltage after unidirectional conduction.

[0119] like Fig.10 and Fig.11 As shown, the output protection circuit 600 includes a third diode D3, a fourth diode D4, an eighth resistor R8 and a ninth resistor R9.

[0120] The anode of the third diode D3 and the cathode of the fourth diode D4 serve together as the battery voltage input terminal of the output protection circuit 600, and are connected to the switch circuit 300 to input the battery voltage; the cathode of the third diode D3 is connected to the first end of the eighth resistor R8, the anode of the fourth diode D4 is connected to the first end of the ninth resistor R9, and the second end of the eighth resistor R8 and the second end of the ninth resistor R9 serve together as the unidirectional conduction and current-limited battery voltage output terminal of the output protection circuit 600 to output the unidirectional conduction and current-limited battery voltage.

[0121] The following is a combination of working principles Figure 10 to Figure 11 As shown for further explanation:

[0122] like Fig.10 As shown, the battery voltage is input to the positive electrode of the first diode D1 and the negative electrode of the second diode D2, the first diode D1 and the second diode D2 conduct the battery voltage unidirectionally, and the unidirectionally conducted battery voltage is output from the negative electrode of the first diode D1 and the positive electrode of the second diode D2 to the multi-resonance circuit 100, the multi-resonance circuit 100 outputs the regulated and current-limited driving DC power to the second end of the fifth resistor R5 and the dry contact S1, the dry contact S1 is connected to form a loop, the regulated and current-limited driving DC power is transmitted to the negative electrode of the photoelectric coupler PC1 through the dry contact S1, the collector of the photoelectric coupler PC1 is connected to the regulated and current-limited battery voltage from the negative electrode of the first transient voltage suppression diode Z1, the photoelectric coupler PC1 is turned on, and a switching signal is output from the emitter of the photoelectric coupler PC1 to the gate of the NMOS Q3, the NMOS Q3 is turned on, the coil of relay K1 is energized, the first normally open contact of relay K1 and the second normally open contact of relay K1 are closed, and the battery voltage is transmitted to the positive electrode of the third diode D3 and the negative electrode of the fourth diode D4. The third diode D3, the fourth diode D4, the eighth resistor R8 and the ninth resistor R9 perform unidirectional conduction and current limiting on the battery voltage, and output the unidirectional conduction and current limiting battery voltage to the bus.

[0123] Fig.11 In the embodiment, the first diode D1 and the second diode D2 conduct the battery voltage in a unidirectional manner, and then the unidirectionally conducted battery voltage is output from the cathode of the first diode D1 and the anode of the second diode D2 to the step-down circuit 500. The step-down circuit 500 steps down the unidirectionally conducted battery voltage and outputs the stepped-down battery voltage to the collector of the photocoupler PC1. The working principle of the remaining circuits is the same as that of the embodiment. Fig.10 The same is not repeated here.

[0124] The embodiment of the present application also provides a UPS power system, including the above-mentioned UPS cold start circuit 10.

[0125] By way of example and not limitation, Fig.12As shown, the power supply system further includes a battery charging and discharging circuit, a PFC circuit, a DC bus circuit, an inverter circuit, a DC converter circuit and a bypass circuit.

[0126] The battery charging and discharging circuit is connected to the DC bus circuit and the UPS cold start circuit 10, and is configured to access the battery voltage, convert the battery voltage into a first voltage, or convert the DC power into a charging voltage to charge the energy storage module.

[0127] The PFC circuit is configured to rectify input AC power to output DC power.

[0128] The DC bus circuit is connected to the PFC circuit and is configured to filter the DC power or the first voltage to output a second voltage.

[0129] The inverter circuit is connected to the DC bus circuit and is configured to invert the second voltage to output the output AC power to the output interface.

[0130] The DC converter circuit is connected to the DC bus circuit and is configured to convert the second voltage into an auxiliary voltage to supply power to each functional module.

[0131] The bypass circuit is configured to transmit the input AC power to the output interface in response to the bypass control signal.

[0132] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0133] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A multi-resonance circuit, characterized in that: It includes a transformer, a first inductor, a first transistor, a second transistor, a second resistor, a third resistor and a second capacitor; The first end of the first inductor, the first end of the second resistor, the first end of the third resistor, the emitter of the first transistor and the emitter of the second transistor are collectively used as the battery voltage input end of the multi-resonance circuit to access the battery voltage; the second end of the first inductor is connected to the center tap of the primary side of the transformer, the collector of the first transistor is connected to the first end of the second capacitor and the first end of the primary side of the transformer, the second end of the second capacitor is connected to the second end of the primary side of the transformer and the collector of the second transistor, the second end of the second resistor is connected to the base of the first transistor and the first end of the auxiliary winding of the transformer, the second end of the third resistor is connected to the base of the second transistor and the second end of the auxiliary winding of the transformer, and the first end of the secondary side of the transformer and the second end of the secondary side of the transformer are collectively used as the driving AC output end of the multi-resonance circuit to output driving AC.

2. The multi-resonance circuit according to claim 1, characterized in that Also including a second transient voltage suppression diode and a third transient voltage suppression diode; The anode of the second transient voltage suppression diode is connected to the emitter of the first transistor, the emitter of the second transistor and the anode of the third transient voltage suppression diode, the cathode of the second transient voltage suppression diode is connected to the collector of the first transistor, the first end of the second capacitor and the first end of the primary side of the transformer, and the cathode of the third transient voltage suppression diode is connected to the second end of the second capacitor, the second end of the primary side of the transformer and the collector of the second transistor.

3. The multi-resonance circuit according to claim 1, characterized in that: Also includes: An input voltage stabilizing and current limiting circuit, configured to stabilize and limit the current of the battery voltage; The input filtering circuit is connected to the input voltage stabilizing and current limiting circuit and is configured to filter the battery voltage after voltage stabilization and current limiting.

4. A UPS cold start circuit, connected between a busbar and a dry contact, characterized in that: The invention comprises a dry contact interface circuit, a switch circuit and a multi-resonance circuit as claimed in any one of claims 1 to 3; the multi-resonance circuit further comprises a rectifier circuit; the rectifier circuit is configured to rectify the driving alternating current to output a driving direct current; The dry contact interface circuit is connected to the multi-resonance circuit and is configured to output a switch signal according to the connectivity of the dry contact and the driving DC power; The switch circuit is connected to the bus bar and the dry contact interface circuit, and is configured to transmit the battery voltage to the bus bar according to the switch signal.

5. The UPS cold start circuit according to claim 4, characterized in that: Also includes: an input protection circuit, connected to the multi-resonance circuit and the switch circuit, and configured to unidirectionally conduct the battery voltage; The switch circuit is specifically configured to transmit the battery voltage after unidirectional conduction to the bus according to the switch signal.

6. The UPS cold start circuit according to claim 5, characterized in that: Also includes: A step-down circuit, connected to the input protection circuit, the multi-resonance circuit and the dry contact interface circuit, configured to step down the battery voltage after unidirectional conduction; The dry contact interface circuit is specifically configured to output the switch signal according to the stepped-down battery voltage, the connectivity of the dry contact, and the driving direct current.

7. The UPS cold start circuit according to claim 4, characterized in that: The dry contact interface circuit includes a photocoupler and a fifth resistor; The collector of the photoelectric coupler serves as the battery voltage input terminal of the dry contact interface circuit to input the battery voltage; the emitter of the photoelectric coupler serves as the switch signal output terminal of the dry contact interface circuit and is connected to the switch circuit to output the switch signal; the positive electrode of the photoelectric coupler is connected to the first end of the fifth resistor, and the second end of the fifth resistor serves as the driving DC input terminal of the dry contact interface circuit and is connected to the multi-resonance circuit to input the driving DC; the negative electrode of the photoelectric coupler is connected to the dry contact.

8. The UPS cold start circuit according to claim 4, characterized in that: The switch circuit includes a relay, an NMOS, a seventh diode, a sixth resistor and a seventh resistor; The first common end of the relay, the first end of the sixth resistor, the second common end of the relay, the source of the NMOS and the first end of the seventh resistor are used together as the battery voltage input end of the switch circuit to input the battery voltage; the second end of the sixth resistor is connected to the cathode of the seventh diode and the first end of the coil of the relay, the second end of the coil of the relay is connected to the drain of the NMOS and the anode of the seventh diode, the gate of the NMOS and the second end of the seventh resistor are used as the switch signal input end of the switch circuit, and are connected to the dry contact interface circuit to input the switch signal; The first normally open contact of the relay and the second normally open contact of the relay serve together as a battery voltage output terminal of the switch circuit to output the battery voltage.

9. A UPS power supply system, characterized in that: The UPS cold start circuit comprises the UPS cold start circuit as claimed in any one of claims 4 to 8.

10. The UPS power supply system according to claim 9, characterized in that: Also includes: A battery charging and discharging circuit, connected to the DC bus circuit and the UPS cold start circuit, configured to access the battery voltage, convert the battery voltage into a first voltage, or convert the DC power into a charging voltage to charge the energy storage module; A PFC circuit configured to rectify input AC power to output the DC power; The DC bus circuit is connected to the PFC circuit and is configured to filter the DC power or the first voltage to output a second voltage; an inverter circuit connected to the DC bus circuit and configured to invert the second voltage to output an output AC power to an output interface; a DC converter circuit, connected to the DC bus circuit, and configured to convert the second voltage into an auxiliary voltage to power various functional modules; The bypass circuit is configured to transmit the input AC power to the output interface in response to a bypass control signal.

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