Standby power supply system with zero time delay response

Abstract

The application discloses a zero-delay-response backup power supply system and belongs to the technical field of switching power supplies. The zero-delay-response backup power supply system comprises an AC / DC conversion circuit, a bidirectional DC / DC conversion circuit, a linear voltage stabilizing circuit, a DC / DC conversion circuit and a first diode and a battery. The output end of the AC / DC conversion circuit is connected in parallel with a DC bus, and the DC bus is connected in parallel with the input end of the DC / DC conversion circuit. The input end of the bidirectional DC / DC conversion circuit is connected across the battery, the output end of the bidirectional DC / DC conversion circuit is connected in parallel with the input end of the linear voltage stabilizing circuit, the output end of the linear voltage stabilizing circuit is connected in parallel with the DC bus, the anode of the first diode is connected to the input positive end of the bidirectional DC / DC conversion circuit, and the cathode of the first diode is connected to the output positive end of the bidirectional DC / DC conversion circuit. The zero-delay-response backup power supply system has high conversion efficiency, small volume and light weight.

Description

Technical Field

[0001] This invention relates to the field of switching power supply technology, and particularly to a backup power system with zero-delay response. Background Technology

[0002] In practical applications, to ensure that the load can continue to be powered even when the external power supply is interrupted, a backup power supply is usually set up. When the external power supply is disconnected, the backup power supply powers the load to ensure its normal operation.

[0003] Figure 1 This is a schematic diagram of a backup power supply in the prior art, which includes an AC / DC conversion circuit 111, n DC / DC conversion circuits, and a battery B1. The input terminal of the AC / DC conversion circuit 111 is connected to an AC power supply V. in1 The alternating current V in1 The AC / DC converter 111 provides single-phase or three-phase alternating current. Its output is connected in parallel to the DC bus BUS. The DC bus BUS is also connected in parallel to the inputs of n DC / DC converters 121 to 12n. The battery B1 is connected in parallel between the DC buses. The outputs of the n DC / DC converters 121 to 12n output the converted DC voltage V. o11 To V o1n The DC voltage V o11 To V o1n They can be different, supplying power to different loads according to their actual needs. When the external power supply is working normally, the AC / DC conversion circuit 111 converts AC power to DC power. According to the different needs of the load, the DC / DC conversion circuits 121 to 12n respectively convert the DC power to the DC voltage V required by the load. o11 To V o1n It outputs power to the load; when the external power supply is interrupted, the battery B1 is connected to the DC bus BUS, and the DC / DC converter circuits 121 to 12n convert the DC bus voltage into the DC voltage V required by the load. o11 To V o1n And output it to the load. However, Figure 1 The intermediate circuit has a DC bus voltage V P It has the disadvantages of wide range but low DC / DC conversion efficiency.

[0004] Figure 2 This is a schematic diagram of another backup power supply in the prior art, using single-phase or three-phase AC power V. in2The input terminal of the UPS circuit 231 is connected, and the output terminal of the UPS circuit 231 is connected to the input terminal of the AC / DC converter circuit 211. The output terminal of the AC / DC converter circuit 211 is connected in parallel to the input terminals of n DC / DC converter circuits 221 to 22n, and the output terminals of the n DC / DC converter circuits 221 to 22n respectively output DC voltage V. o21 To V o2n The UPS circuit 231 reduces the overall system transmission efficiency, and the response time of the UPS circuit requires a certain holding time from the AC / DC conversion circuit, thus preventing the AC / DC conversion circuit from achieving optimal efficiency. In addition, it requires a large number of energy storage electrolytic capacitors, resulting in high system cost, large size, and short lifespan.

[0005] Figure 3 , 4 The backup power supply introduces a bidirectional DC / DC converter circuit. Because the bidirectional DC / DC converter circuit has a certain response time, there is a requirement for the hold time of the AC / DC converter circuit. Therefore, the AC / DC converter circuit needs to adopt a two-stage conversion structure of PFC and DC / DC conversion. At the same time, a large number of energy storage electrolytic capacitors are required, which results in high cost, short lifespan and large size of the entire system. In addition, the efficiency of the AC / DC converter circuit is also limited. Summary of the Invention

[0006] The present invention aims to provide a high-efficiency backup power system with zero-delay response.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A zero-delay response backup power system includes an AC / DC converter circuit, a bidirectional DC / DC converter circuit, a linear regulator circuit, a DC / DC converter circuit, a first diode, and a battery. The output terminal of the AC / DC converter circuit is connected in parallel with a DC bus, and the DC bus is connected in parallel with the input terminal of the DC / DC converter circuit. The input terminal of the bidirectional DC / DC converter circuit is connected in parallel with both ends of the battery. The output terminal of the bidirectional DC / DC converter circuit is connected in parallel with the input terminal of the linear regulator circuit, and the output terminal of the linear regulator circuit is connected in parallel with the DC bus. The anode of the first diode is connected to the positive input terminal of the bidirectional DC / DC converter circuit, and the cathode of the first diode is connected to the positive output terminal of the bidirectional DC / DC converter circuit.

[0009] The aforementioned bidirectional DC / DC converter circuit includes a first inductor, a third switch, and a fourth switch, and the connection of the first inductor, the third switch, and the fourth switch is a Boost topology.

[0010] In another specific embodiment, the aforementioned zero-delay response backup power system further includes a first switch, which is connected in series with the first diode.

[0011] The aforementioned bidirectional DC / DC converter circuit includes a second switch, a third switch, a fourth switch, a fifth switch, and a second inductor. The connection between the second switch, the third switch, the fourth switch, the fifth switch, and the second inductor is a Buck-Boost topology.

[0012] In one specific embodiment, the linear voltage regulator circuit includes a first switching transistor, a first driving module, a first resistor, a second resistor, and a first operational amplifier. The positive input terminal of the linear voltage regulator circuit is connected to the drain of the first switching transistor, and the source of the first switching transistor is connected to the positive output terminal of the linear voltage regulator circuit. The first resistor and the second resistor are connected in series, and their two ends are connected in parallel with the output terminal of the linear voltage regulator circuit. The midpoint of the series connection between the first resistor and the second resistor is connected to the negative input terminal of the first operational amplifier. The positive input terminal of the first operational amplifier is connected to a reference voltage. The output terminal of the first operational amplifier is connected to the input terminal of the first driving module, and the output terminal of the first driving module is connected to the gate of the first switching transistor. The negative input terminal of the linear voltage regulator circuit is connected to its negative output terminal.

[0013] In one specific embodiment, the linear voltage regulator circuit includes a second switching transistor, a second driving module, a third resistor, a fourth resistor, and a second operational amplifier. The negative input terminal of the linear voltage regulator circuit is connected to the source of the second switching transistor, and the drain of the second switching transistor is connected to the negative output terminal of the linear voltage regulator circuit. The third resistor and the fourth resistor are connected in series, and their two ends are connected in parallel with the output terminal of the linear voltage regulator circuit. The midpoint of the series connection between the third resistor and the fourth resistor is connected to the negative input terminal of the second operational amplifier. The positive input terminal of the second operational amplifier is connected to the reference voltage. The output terminal of the second operational amplifier is connected to the input terminal of the second driving module, and the output terminal of the second driving module is connected to the gate of the second switching transistor. The positive input terminal of the linear voltage regulator circuit is connected to its positive output terminal.

[0014] The aforementioned DC bus is connected in parallel with the input terminals of multiple DC / DC conversion circuits, and the output terminals of the multiple DC / DC conversion circuits are respectively connected to loads.

[0015] Beneficial effects: The zero-delay response backup power system of the present invention does not require energy storage and hold time for the AC / DC conversion circuit, and can achieve zero-delay response, making the entire system highly efficient, small in size and light in weight.

[0016] To make the above-mentioned features and advantages of the invention more apparent and understandable, specific embodiments are described below, and detailed descriptions are provided in conjunction with the accompanying drawings. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the first type of backup power supply in the prior art.

[0018] Figure 2 This is a schematic diagram of a second type of backup power supply in the prior art.

[0019] Figure 3 This is a schematic diagram of a third type of backup power supply in the prior art.

[0020] Figure 4 This is a schematic diagram of the fourth type of backup power supply in the prior art.

[0021] Figure 5 This is a block diagram of a specific embodiment of the zero-delay response backup power system of the present invention.

[0022] Figure 6 for Figure 5 A schematic diagram of a specific embodiment of the medium linear voltage regulator circuit 561.

[0023] Figure 7 for Figure 5 A schematic diagram of another specific embodiment of the medium linear voltage regulator circuit 561.

[0024] Figure 8 for Figure 5 A schematic diagram of a specific embodiment of the bidirectional DC / DC converter circuit 541.

[0025] Figure 9 for Figure 5 A schematic diagram of another specific embodiment of the bidirectional DC / DC converter circuit 541.

[0026] Figure 10 This is a block diagram of another specific embodiment of the zero-delay response backup power system of the present invention.

[0027] Figure 11 for Figure 10 A schematic diagram of a specific embodiment of the bidirectional DC / DC converter circuit 541.

[0028] In the accompanying drawings, similar reference numerals refer to the same elements. Detailed Implementation

[0029] To make the objectives and technical solutions of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0030] Figure 5 This is a block diagram of a specific embodiment of the zero-delay response backup power system of the present invention. Figure 5 As shown, the zero-delay response backup power system of the present invention includes an AC / DC converter circuit 511, a bidirectional DC / DC converter circuit 541, a linear voltage regulator circuit 561, n DC / DC converter circuits 521 to 52n, a diode D1, and a battery B5. The input terminal of the AC / DC converter circuit 511 is connected to a single-phase or three-phase AC power supply V. in5 The output terminal of the AC / DC converter circuit 511 is connected in parallel to a DC bus BUS. The DC bus BUS is connected in parallel to the input terminals of n DC / DC converter circuits 521 to 52n, where n is an integer and at least 1. The output terminals of the n DC / DC converter circuits 521 to 52n respectively output voltage V. o51 To V o5n Each is assigned to its respective load; the negative output terminal of the AC / DC converter 511 is connected to the negative terminal of the battery B5, the input terminal of the bidirectional DC / DC converter 541 is connected in parallel to the two ends of the battery B5, the output terminal of the bidirectional DC / DC converter 541 is connected in parallel to the input terminal of the linear voltage regulator 561, the output terminal of the linear voltage regulator 561 is connected in parallel to the DC bus BUS, the anode of the diode D1 is connected to the positive input terminal of the bidirectional DC / DC converter 541, and the cathode of the diode D1 is connected to the positive output terminal of the bidirectional DC / DC converter 541.

[0031] Figure 5 The battery B5 described above, when fully charged, still has a voltage lower than the DC bus voltage V. P When the external power supply is working normally, single-phase or three-phase AC power is converted into DC bus voltage V by the AC / DC conversion circuit 511. P Depending on the different load requirements, n DC / DC converter circuits 521 to 52n convert the DC bus voltage V P Converted into the DC voltage V required by the load o51 To V o5n And output to the load, the DC voltage V o51 To V o5n They may not be the same.

[0032] Meanwhile, the DC bus voltage V P The battery B5 is charged through the linear voltage regulator circuit 561 and the bidirectional DC / DC converter circuit 541.

[0033] When the external power supply is interrupted, battery B5 discharges instantaneously through diode D1 and linear voltage regulator circuit 561 and connects to the DC bus BUS without any delay. After the bidirectional DC / DC converter circuit 541 starts, it raises the voltage of battery B5 and supplies power to the DC bus BUS through the linear voltage regulator circuit 561. When the DC bus voltage V... P When a certain set value is reached, i.e., the DC bus voltage V... P When the voltage is higher than that of battery B5, diode D1 is disconnected. The linear voltage regulator circuit 561 ensures that the output voltage of the bidirectional DC / DC converter circuit 541 is higher than the DC bus voltage V. P That portion of the voltage drop ensures the DC bus voltage V P The DC / DC converter circuits 521 to 52n will convert the DC bus voltage V to a value that remains unchanged or is not lower than a set value. P Converted into the DC voltage V required by the load o51 To V o5n And output it to the load.

[0034] Figure 6 Show Figure 5 A schematic diagram of a specific embodiment of the linear voltage regulator circuit 561 described herein. (See diagram below.) Figure 6 As shown, the linear voltage regulator circuit 661 includes a switching transistor Q1, a driving module 6611 for the switching transistor Q1, resistors R1 and R2, an operational amplifier A1, resistor R3, and capacitor C1. The positive input terminal of the linear voltage regulator circuit 661 is connected to the drain of the switching transistor Q1, and the source of the switching transistor Q1 is connected to the positive output terminal of the linear voltage regulator circuit. Resistors R1 and R2 are connected in series, and their two ends are connected in parallel with the output terminal of the linear voltage regulator circuit 661. The midpoint of the series connection between resistors R1 and R2 is connected to the negative input terminal of the operational amplifier A1, and the positive input terminal of the operational amplifier A1 is connected to a reference voltage V. ref The negative input terminal of operational amplifier A1 is connected to the first terminal of capacitor C1, the second terminal of capacitor C1 is connected to the first terminal of resistor R3, the second terminal of resistor R3 is connected to the output terminal of operational amplifier A1, the output terminal of operational amplifier A1 is connected to the input terminal of driver module 6611 of switching transistor Q1, and the output terminal of driver module 6611 of switching transistor Q1 is connected to the gate of switching transistor Q1. The negative input terminal of linear regulator circuit 661 is connected to its negative output terminal. Operational amplifier A1 acquires the voltage between DC buses and compares it with a set voltage V.ref After comparison, the output signal is sent to the drive module 6611 of the switch Q1. The drive module 6611 then performs further calculations and outputs the drive signal for the switch Q1, thereby ensuring the DC bus voltage V. P It remains unchanged or is not lower than a certain set value.

[0035] Figure 7 Show Figure 5 A schematic diagram of another specific embodiment of the linear voltage regulator circuit 561 described herein. (See diagram below.) Figure 7 As shown, the linear voltage regulator circuit 761 includes a switching transistor Q2, a driving module 7611 for the switching transistor Q2, resistors R4 and R5, an operational amplifier A2, resistor R6, and capacitor C2. The negative input terminal of the linear voltage regulator circuit 761 is connected to the source of the switching transistor Q2, and the drain of the switching transistor Q2 is connected to the negative output terminal of the linear voltage regulator circuit 761. Resistors R4 and R5 are connected in series, and their two ends are connected in parallel with the output terminal of the linear voltage regulator circuit 761. The midpoint of the series connection between resistors R4 and R5 is connected to the negative input terminal of the operational amplifier A2, and the positive input terminal of the operational amplifier A2 is connected to a reference voltage V. ref The negative input terminal of operational amplifier A2 is connected to the first terminal of resistor R6, the second terminal of resistor R6 is connected to the first terminal of capacitor C2, the second terminal of capacitor C2 is connected to the output terminal of operational amplifier A2, the output terminal of operational amplifier A2 is connected to the input terminal of the driver module 7611 of switching transistor Q2, and the output terminal of the driver module 7611 of switching transistor Q2 is connected to the gate of switching transistor Q2. The positive input terminal of the linear regulator circuit 761 is connected to its positive output terminal. Operational amplifier A2 acquires the voltage between the DC buses and compares it with a set voltage V. ref After comparison, the output signal is sent to the drive module 7611 of the switch Q2. The drive module 7611 then performs further calculations and outputs the drive signal for the switch Q2, thereby ensuring the DC bus voltage V. P It remains unchanged or is not lower than a certain set value.

[0036] Figure 8 Show Figure 5 A schematic diagram of a specific embodiment of the bidirectional DC / DC converter circuit 541 described herein. Figure 8As shown, the bidirectional DC / DC converter circuit 841 includes an inductor L1, a switch Q3, and a switch Q4. The inductor L1, the switch Q3, and the switch Q4 are connected in a Boost topology, meaning the bidirectional DC / DC converter circuit 841 is a boost circuit. The positive input terminal of the DC / DC converter circuit 841 is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the positive output terminal of the DC / DC converter circuit 841. When the voltage of the battery B5 is lower than the DC bus voltage V... P At this time, the DC / DC converter circuit 841 starts working, converting the DC bus voltage V... P Maintain the value unchanged or not lower than a certain set value.

[0037] Figure 9 Show Figure 5 A schematic diagram of another specific embodiment of the bidirectional DC / DC converter circuit 541 described herein. (See diagram below.) Figure 9 As shown, the bidirectional DC / DC converter circuit 941 includes an inductor L1, a switch Q3, and a switch Q4. The inductor L1, the switch Q3, and the switch Q4 are connected in a Boost topology, meaning the bidirectional DC / DC converter circuit 941 is a boost circuit. The anode of the diode D1 is connected to the source of the switch Q4, and the cathode of the diode D1 is connected to the positive output terminal of the DC / DC converter circuit 941. When the voltage of the battery B5 is lower than the DC bus voltage V... P At that time, the DC / DC converter circuit 941 starts working, converting the DC bus voltage V... P Maintain the value unchanged or not lower than a certain set value.

[0038] Figure 10 This is a block diagram of another specific embodiment of the zero-delay response backup power system of the present invention. (See diagram below.) Figure 10 As shown, with Figure 5 The difference is that a switch K1 is connected in series between the positive input terminal of the bidirectional DC / DC converter circuit 541 and the anode of the diode D1.

[0039] Figure 11 for Figure 10 A schematic diagram of a specific embodiment of the bidirectional DC / DC converter circuit 541. (See diagram below.) Figure 11 As shown, the bidirectional DC / DC converter circuit 1141 includes switches S1, S2, S3, S4 and inductor L2. The switches S1, S2, S3, S4 and inductor L2 form a Buck-Boost topology, that is, the bidirectional DC / DC converter circuit 1141 is a buck-boost circuit.

[0040] Figure 10When the battery B5 is fully charged, its voltage is higher than the DC bus voltage V. P When the external power supply is working normally, single-phase or three-phase AC power is converted into DC bus voltage V by the AC / DC conversion circuit 511. P Depending on the different load requirements, n DC / DC converter circuits 521 to 52n convert the DC bus voltage V P Converted into the DC voltage V required by the load o51 To V o5n And output to the load, the DC voltage V o51 To V o5n They may not be the same.

[0041] At the same time, the DC bus voltage V P The battery B5 is charged through the linear voltage regulator circuit 561 and the bidirectional DC / DC converter circuit 541. During this time, the switch K1 is open. After charging is complete, the switch K1 is closed. The switch K1 receives system control signals through its drive circuit (not shown in the figure) and remains in the off state during the charging process of the battery B5 until the battery is fully charged. Then, the switch K1 is opened by the system control signal and enters the standby state.

[0042] When the external power supply is interrupted, if battery B5 is fully charged and its voltage is higher than the DC bus voltage V, P Then, the battery B5 is instantaneously discharged and connected to the DC bus through the diode D1 and the linear voltage regulator circuit 561 without any delay. The linear voltage regulator circuit 561 handles the situation where the battery voltage is higher than the DC bus voltage V. P That portion of the voltage drop ensures the DC bus voltage V P The DC / DC converter circuits 521 to 52n will convert the DC bus voltage V to a value that remains unchanged or is not lower than a set value. P Converted into the DC voltage V required by the load o51 To V o5n And output to the load; if the voltage of battery B5 drops to near or below the DC bus voltage V P When the diode D1 is turned off, the linear voltage regulator circuit 561 is fully turned on, and the bidirectional DC / DC converter circuit 541 starts working, converting the DC bus voltage V... P Maintain the value unchanged or not lower than a certain set value.

[0043] Without a linear voltage regulator circuit, the maximum voltage of battery B5 can only be lower than or equal to the DC bus voltage V. PTherefore, the bidirectional DC / DC converter circuit 541 can only operate in standby mode. Although diode D1 allows the battery to discharge instantaneously to the DC bus, the voltage drop of diode D1 and the internal resistance of the battery cause the DC bus voltage to drop instantaneously from the normal operating voltage to a certain voltage (the specific drop voltage amplitude depends on the battery design, generally around tens of volts). Furthermore, the bidirectional DC / DC converter circuit 541 still has a certain delay in responding to load jumps. This delay further reduces the DC bus voltage V. P The drop in voltage leads to a wider range of input voltages for the subsequent DC / DC converter circuits 521 to 52n, resulting in suboptimal efficiency for these circuits. Furthermore, the preceding AC / DC converter circuit 511 requires a two-stage architecture with a large number of energy storage capacitors to maintain its hold-up function. Therefore, to maintain stable bus voltage, the full-charge voltage of the battery needs to be slightly higher than the bus voltage, depending on the battery type. Therefore, for... Figure 5 The embodiment uses a boost circuit, but if this boost circuit is used to charge the battery, the battery voltage cannot exceed the bus voltage. If the battery voltage is to be higher than the bus voltage, a separate charging circuit is needed. Using a buck-boost circuit, the battery voltage can be charged and made higher than the bus voltage.

[0044] This invention employs a boost circuit or a combination of a boost circuit and a linear regulator circuit, allowing a fully charged battery B5 to discharge instantaneously through the diode D1 and the linear regulator circuit 561 without any delay, thereby ensuring the DC bus voltage V. P After the external power supply fails, it immediately receives replenished power to ensure the DC bus voltage V. P The input voltage of the subsequent DC / DC converter circuit remains constant or is not lower than a certain set value, so that the variation range of the input voltage is almost zero, ensuring its highest efficiency operation.

[0045] The linear voltage regulator circuit 561 is used to compensate for the situation where battery B5 is fully charged and the battery voltage is higher than the required DC bus voltage V. P The voltage drop during discharge. In the initial stage of discharge of a fully charged battery B5, the voltage of battery B5 drops rapidly, and the battery voltage quickly approaches or falls below the DC bus voltage V. P At this time, the linear voltage regulator circuit 561 is fully turned on, and its voltage drops to 0. Simultaneously, the boost circuit 521 starts working, maintaining the DC bus voltage at V. P Or not lower than a certain set value.

[0046] The zero-delay response backup power system of the present invention can also be applied to three-phase AC power systems. Its connection method and working principle are similar to those of the above embodiments, and will not be repeated here.

[0047] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A zero-delay response backup power system, characterized in that, The system includes an AC / DC converter circuit, a bidirectional DC / DC converter circuit, a linear voltage regulator circuit, a DC / DC converter circuit, a first diode, and a battery. The output terminal of the AC / DC converter circuit is connected in parallel with a DC bus, and the DC bus is connected in parallel with the input terminal of the DC / DC converter circuit. The input terminal of the bidirectional DC / DC converter circuit is connected in parallel with the two ends of the battery. The output terminal of the bidirectional DC / DC converter circuit is connected in parallel with the input terminal of the linear voltage regulator circuit, and the output terminal of the linear voltage regulator circuit is connected in parallel with the DC bus. The anode of the first diode is connected to the positive input terminal of the bidirectional DC / DC converter circuit, and the cathode of the first diode is connected to the positive output terminal of the bidirectional DC / DC converter circuit. The linear voltage regulator circuit includes a first switching transistor, the positive input terminal of the linear voltage regulator circuit is connected to the drain of the first switching transistor, and the source of the first switching transistor is connected to the positive output terminal of the linear voltage regulator circuit. The linear voltage regulator circuit further includes a first driving module, a first resistor, a second resistor, and a first operational amplifier. The first resistor and the second resistor are connected in series, and the two ends of the series connection are connected in parallel with the output terminal of the linear voltage regulator circuit. The midpoint of the series connection between the first resistor and the second resistor is connected to the negative input terminal of the first operational amplifier. The positive input terminal of the first operational amplifier is connected to a reference voltage. The output terminal of the first operational amplifier is connected to the input terminal of the first driving module. The output terminal of the first driving module is connected to the gate of the first switching transistor. The negative input terminal of the linear voltage regulator circuit is connected to its negative output terminal.

2. The zero-delay response backup power system as described in claim 1, characterized in that, It also includes a first switch, which is connected in series with the first diode.

3. The zero-delay response backup power system as described in claim 1, characterized in that, The bidirectional DC / DC converter circuit includes a first inductor, a third switch, and a fourth switch, and the connection of the first inductor, the third switch, and the fourth switch is a Boost topology.

4. The zero-delay response backup power system as described in claim 2, characterized in that, The bidirectional DC / DC converter circuit includes a second switch, a third switch, a fourth switch, a fifth switch, and a second inductor. The connection between the second switch, the third switch, the fourth switch, the fifth switch, and the second inductor is a Buck-Boost topology.

5. The zero-delay response backup power system as described in claim 1 or 2, characterized in that, The DC bus is connected in parallel with the input terminals of the multiple DC / DC converter circuits, and the output terminals of the multiple DC / DC converter circuits are respectively connected to the load.

6. A zero-delay response backup power system, characterized in that, The system includes an AC / DC converter circuit, a bidirectional DC / DC converter circuit, a linear voltage regulator circuit, a DC / DC converter circuit, a first diode, and a battery. The output terminal of the AC / DC converter circuit is connected in parallel with a DC bus, and the DC bus is connected in parallel with the input terminal of the DC / DC converter circuit. The input terminal of the bidirectional DC / DC converter circuit is connected in parallel with the two ends of the battery. The output terminal of the bidirectional DC / DC converter circuit is connected in parallel with the input terminal of the linear voltage regulator circuit, and the output terminal of the linear voltage regulator circuit is connected in parallel with the DC bus. The anode of the first diode is connected to the positive input terminal of the bidirectional DC / DC converter circuit, and the cathode of the first diode is connected to the positive output terminal of the bidirectional DC / DC converter circuit. The linear voltage regulator circuit includes a second switching transistor. The negative input terminal of the linear voltage regulator circuit is connected to the source of the second switching transistor, and the drain of the second switching transistor is connected to the negative output terminal of the linear voltage regulator circuit. The linear voltage regulator circuit further includes a second driving module, a third resistor, a fourth resistor, and a second operational amplifier. The third resistor and the fourth resistor are connected in series, and their two ends are connected in parallel with the output terminal of the linear voltage regulator circuit. The midpoint of the series connection between the third resistor and the fourth resistor is connected to the negative input terminal of the second operational amplifier. The positive input terminal of the second operational amplifier is connected to a reference voltage. The output terminal of the second operational amplifier is connected to the input terminal of the second driving module. The output terminal of the second driving module is connected to the gate of the second switching transistor. The positive input terminal of the linear voltage regulator circuit is connected to its positive output terminal.

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