Control methods for power supply circuits, power supply circuits and energy storage devices

Abstract

This application discloses a control method, a power supply circuit, and an energy storage device for a power supply circuit. The control method includes: upon receiving a power supply command, controlling a first switching module to conduct while keeping a second switching module open, so that the AC source charges the bus capacitor after passing through the first switching module, a current limiting module, and an AC / DC conversion module; when the voltage of the bus capacitor is greater than a first preset voltage, driving the AC / DC conversion module to convert the AC power limited by the current limiting module and output it to the DC bus, thus charging the bus capacitor; when the voltage of the bus capacitor is greater than a second preset voltage, controlling the second switching module to conduct and controlling the first switching module to open, and controlling the AC / DC conversion module to output a target power supply voltage; the second preset voltage is greater than the voltage of the AC source. This application can avoid damage to components in the circuit due to large voltage differences during circuit switching, reduce the failure rate of the power supply circuit, and improve the overall reliability of the power supply circuit.

Description

Technical Field

[0001] This application belongs to the field of circuit technology, specifically relating to a control method for a power supply circuit, a power supply circuit, and an energy storage device. Background Technology

[0002] Energy storage devices are ubiquitous in people's daily lives. They consist of battery modules and power supply circuits, which charge and discharge the battery modules. To ensure normal circuit operation and avoid instantaneous current surges during startup, a soft-start method is typically used. This involves first controlling the power supply circuit to operate in pre-charging mode, thereby pre-charging the energy storage devices such as capacitors on the DC bus. This prevents excessive charging signals in the early stages of power-on, which could damage the devices.

[0003] However, when the control power supply circuit switches to the normal power supply mode after the pre-charging is completed, the power supply circuit has certain differences in different modes. These differences result in a large voltage difference in the circuit, which causes a large current to flow through the circuit components, thereby damaging the circuit components and causing the energy storage device to malfunction.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this application is to provide a control method for a power supply circuit, a power supply circuit, and an energy storage device to solve the problem of device damage during the slow start-up process in related technologies.

[0006] According to one aspect of the embodiments of this application, a control method for a power supply circuit is provided. The power supply circuit includes an AC / DC conversion module, a first switching module, a second switching module, a current limiting module, and a bus capacitor. The output terminal of the AC / DC conversion module is connected to a DC bus for connection to a subsequent circuit. The bus capacitor is connected in parallel between the positive and negative terminals of the DC bus. The second switching module is used to connect an AC source to the AC / DC conversion module. The first switching module and the current limiting module are connected in series and then in parallel across the two ends of the second switching module. The control method includes:

[0007] Upon receiving a power supply command, the first switch module is turned on while the second switch module remains off, so that the AC source is output to the DC bus after passing through the first switch module, the current limiting module, and the AC / DC conversion module, and charges the bus capacitor.

[0008] When the voltage of the bus capacitor is detected to be greater than the first preset voltage, the AC / DC conversion module is driven to convert the AC power limited by the current limiting module and output it to the DC bus, and to charge the bus capacitor.

[0009] When the voltage of the bus capacitor is detected to be greater than the second preset voltage, the second switch module is controlled to turn on and the first switch module is controlled to turn off. The AC / DC conversion module is controlled according to the target power supply voltage of the subsequent circuit and the input voltage of the AC source to output the target power supply voltage. The second preset voltage is greater than the first preset voltage and the second preset voltage is greater than the voltage of the AC source.

[0010] In one embodiment of this application, before the step of driving the AC / DC conversion module to convert the AC power limited by the current limiting module and output it to the DC bus to charge the bus capacitor when the voltage of the bus capacitor is detected to be greater than a first preset voltage, the method further includes: performing a short-circuit detection on the AC / DC conversion module when the conduction time of the first switch module reaches a preset time; and detecting whether the voltage of the bus capacitor is greater than the first preset voltage when it is determined that the AC / DC conversion module is not short-circuited. The first switch module is briefly closed to form a complete circuit, and the voltage of the AC / DC conversion module is detected to confirm the state of the AC / DC conversion module before proceeding to subsequent working steps.

[0011] In one embodiment of this application, the short-circuit detection of the AC / DC converter module includes: detecting whether the output voltage of the AC / DC converter module is lower than a preset voltage threshold; determining that the AC / DC converter module is short-circuited when the output voltage of the AC / DC converter module is lower than the preset voltage threshold; and determining that the AC / DC converter module is not short-circuited when the output voltage of the AC / DC converter module is greater than the preset voltage threshold. Performing this step confirms that the AC / DC converter module is functioning normally, rather than being in a faulty state.

[0012] In one embodiment of this application, after performing short-circuit detection on the AC / DC conversion module, the method further includes: controlling the first switching module to disconnect when a short circuit is determined in the AC / DC conversion module. Performing this step disconnects the first switching module, preventing damage to the electrical components in the AC / DC conversion module under short-circuit conditions.

[0013] In one embodiment of this application, before controlling the first switch module to turn on and keeping the second switch module off when a power supply command is received, the method further includes: performing voltage detection on the AC source to determine whether the voltage of the AC source is a valid voltage; and when it is determined that the voltage of the AC source is a valid voltage, performing the step of controlling the first switch module to turn on and keeping the second switch module off when a power supply command is received. Performing this step confirms that the AC source has a valid voltage, ensuring the normal operation of charging the energy storage device.

[0014] In one embodiment of this application, the step of detecting the voltage of the AC source to determine whether the voltage of the AC source is a valid voltage includes: detecting whether the effective voltage value of the AC source is within a preset voltage range, and detecting whether the voltage frequency of the AC source is within a preset frequency range; when the effective voltage value of the AC source is within the preset voltage range and the voltage frequency of the AC source is within the preset frequency range, determining that the voltage of the AC source is a valid voltage; when the effective voltage value of the AC source is not within the preset voltage range, or when the voltage frequency of the AC source is not within the preset frequency range, determining that the voltage of the AC source is not a valid voltage.

[0015] According to one aspect of the embodiments of this application, a power supply circuit is provided, including: an AC / DC conversion module, a first switching module, a second switching module, a current limiting module, a bus capacitor, and a control module;

[0016] The output terminal of the AC / DC conversion module is connected to the DC bus to connect with the subsequent circuit; the bus capacitor is connected in parallel between the positive and negative terminals of the DC bus; the second switching module is used to connect the AC source and the AC / DC conversion module; the first switching module and the current limiting module are connected in series and then in parallel across the two ends of the second switching module.

[0017] The control module is used to control the first switch module to be turned on and keep the second switch module in the off state when a power supply command is received, so that the AC source is output to the DC bus after passing through the first switch module, the current limiting module and the AC / DC conversion module, and charges the bus capacitor.

[0018] The control module is also used to drive the AC / DC conversion module to convert the AC power limited by the current limiting module to the DC bus and output it to the DC bus when the voltage of the bus capacitor is detected to be greater than the first preset voltage, and to charge the bus capacitor.

[0019] The control module is further configured to, when detecting that the voltage of the bus capacitor is greater than the second preset voltage, control the second switch module to turn on and control the first switch module to turn off, and control the AC / DC conversion module according to the target power supply voltage of the downstream circuit and the voltage of the AC source, so as to output the target power supply voltage; wherein the second preset voltage is greater than the first preset voltage and the second preset voltage is greater than the voltage of the AC source.

[0020] In one embodiment of this application, the AC / DC conversion module includes a rectifier bridge, an inductor, and a switching transistor;

[0021] The first input terminal of the rectifier bridge is connected in series with the second switching module to be connected to the live wire terminal of the AC source. The second input terminal of the rectifier bridge is used to connect to the neutral wire terminal of the AC source. The first output terminal of the rectifier bridge is connected to the first terminal of the inductor. The second output terminal of the rectifier bridge is connected to the second terminal of the switching transistor.

[0022] The second end of the inductor is connected to the first end of the switching transistor; the control end of the switching transistor is connected to the control module.

[0023] The first end of the switching transistor is also connected to the first output end of the AC / DC conversion module, and the second end of the switching transistor is also connected to the second output end of the AC / DC conversion module.

[0024] In one embodiment of this application, the AC / DC conversion module further includes a reverse protection diode, the anode of which is connected to the first terminal of the switching transistor, and the cathode of which is connected to the first output terminal of the AC / DC conversion module.

[0025] According to one aspect of the embodiments of this application, an energy storage device is provided, including a battery module and a power supply circuit provided in any embodiment of this application, wherein the battery module serves as a downstream circuit of the power supply circuit.

[0026] In the technical solution provided in this application embodiment, the power supply circuit includes an AC / DC conversion module, a first switching module, a second switching module, a current limiting module, and a bus capacitor. Since the output terminal of the AC / DC conversion module is on the DC bus to connect with the subsequent circuit, and the bus capacitor is connected in parallel between the positive and negative terminals of the DC bus (BUS+, BUS-), and the second switching module is used to connect the AC source and the AC / DC conversion module, and the first switching module and the current limiting module are connected in series and then in parallel across the second switching module, when a power supply command is received, by controlling the first switching module to turn on and the second switching module to turn off, the current limiting module, the first switching module, and the AC / DC conversion module form a charging path between the AC source and the bus capacitor. The AC power provided by the AC source is current-limited by the current limiting module, and then output to the DC bus through the first switching module and the AC / DC conversion module, charging the bus capacitor. When the voltage of the bus capacitor is detected to be greater than the first preset voltage, the AC / DC converter module is driven to convert the AC power limited by the current limiting module and output it to the DC bus, charging the bus capacitor. At this time, the first switch module is turned on, and the AC / DC converter module enters boost mode under the action of the drive signal, converting the AC power limited by the current limiting module to charge the bus capacitor, so that the voltage of the bus capacitor increases with the charging time. When the voltage of the bus capacitor is detected to be greater than the second preset voltage, the second switch module is controlled to turn on, and the first switch module is controlled to turn off. At this time, the second switch module and the AC / DC converter module form a charging path between the AC source and the bus capacitor, realizing the switching of the charging path when the AC / DC converter module is in boost mode. Finally, the AC / DC converter module is controlled according to the target supply voltage of the subsequent circuit and the input voltage of the AC source, and then the target supply voltage is output through this charging path. Since the second preset voltage is greater than the first preset voltage and the second preset voltage is greater than the voltage of the AC source, a large voltage difference will not be generated between the AC source and the bus capacitor during the switching process of the above charging path. This can avoid damage to the components in the circuit caused by a large voltage difference during the circuit switching process, reduce the failure rate of the power supply circuit, and improve the overall reliability of the power supply circuit.

[0027] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0028] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0029] Figure 1 The diagram illustrates a structural block diagram of a power supply circuit provided in one embodiment of this application.

[0030] Figure 2 The flowchart illustrating a control method for a power supply circuit provided in one embodiment of this application is shown schematically.

[0031] Figure 3 The diagram illustrates a specific structural block diagram of a power supply circuit provided in one embodiment of this application.

[0032] Figure 4 The schematic diagram illustrates a structural block diagram of a power supply circuit provided in one embodiment of this application.

[0033] Figure 5 A schematic diagram of a power supply circuit provided in one embodiment of this application is shown.

[0034] Figure 6 schematically shown Figure 5 The diagram shows the timing sequence of the power supply circuit.

[0035] Figure 7 A schematic diagram of a power supply circuit provided in another embodiment of this application is shown.

[0036] Figure 8 A schematic block diagram of an energy storage device provided in one embodiment of this application is shown. Detailed Implementation

[0037] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0038] Energy storage devices typically undergo pre-charging. If the pre-charging circuit is switched to the main charging circuit, the voltage difference across the circuit components may be too large, resulting in excessive current flowing through the circuit components. This can easily lead to damage to the circuit components and prevent the energy storage device from functioning properly.

[0039] Figure 1 A schematic block diagram of a power supply circuit applying the technical solution of this application is shown.

[0040] like Figure 1As shown, the power supply circuit 100 provided in this embodiment includes an AC / DC conversion module 110, a first switching module 120, a second switching module 130, a current limiting module 140, and a bus capacitor 150. The output terminal of the AC / DC conversion module 110 is on the DC bus (BUS+, BUS-) to connect to the subsequent circuit (not shown in the figure). The bus capacitor 150 is connected in parallel between the positive and negative terminals of the DC bus (BUS+, BUS-). The second switching module 130 is used to connect the AC source 200 and the AC / DC conversion module 110. The first switching module 120 and the current limiting module 140 are connected in series and then in parallel across the second switching module 130.

[0041] In this embodiment, the AC source 200 is used to provide AC power, which can be the mains power grid or a power source with AC power output capability, such as a battery or generator.

[0042] As an example, assuming the AC source 200 is a generator, when the generator is used to charge the bus capacitor 150, the AC power supplied by the generator is converted into DC power by the AC / DC conversion module 110 in the power supply circuit 100. The DC power is then output to the DC bus (BUS+, BUS-) to charge the bus capacitor 150 connected to the DC bus (BUS+, BUS-) and to provide power to the subsequent circuits connected to the DC bus (BUS+, BUS-).

[0043] Specifically, the electrical energy on the DC bus (BUS+, BUS-) can be directly used to power subsequent circuits, or it can be supplied to the corresponding electrical devices after passing through at least one DC / DC conversion module. The AC / DC conversion module 110 can be a bridge rectifier circuit composed of a rectifier bridge and a boost circuit, such as a PFC circuit. The rectifier bridge can be composed of diodes and can realize the conversion between AC and DC, while the boost circuit can include inductors and freewheeling switches, etc., which can control the switching logic and duty cycle of the freewheeling switch of the boost circuit to boost the voltage.

[0044] It is understandable that, in specific implementations, the AC / DC conversion module 110 may also use existing AC / DC conversion circuits, such as traditional power factor correction (PFC) circuits, to achieve its related functions, and no restrictions are imposed here.

[0045] like Figure 1In this embodiment, when the first switch module 120 is turned on and the second switch module 130 is turned off, the AC power provided by the AC source 200 is limited by the current limiting module 140 and then transmitted to the AC / DC conversion module 110 through the first switch module 120. When the first switch module 120 is turned off and the second switch module 130 is turned on, the AC power provided by the AC source 200 is transmitted to the AC / DC conversion module 110 through the second switch module 130.

[0046] In some embodiments, the bus capacitor 150 can be a single capacitor or a capacitor bank consisting of multiple capacitors connected in parallel, and there is no limitation here.

[0047] Figure 2 A flowchart illustrating a control method for a power supply circuit provided in one embodiment of this application is shown schematically. Figure 2 The control method shown is applied to Figure 1 Or the charging circuit provided in other embodiments of this application. In all embodiments of this application, the execution subject of the control method of the power supply circuit can be the control module in the power supply circuit ( Figure 1 (Not shown in the image). Specifically, it can be a controller MCU, or it can be an MCU that uses other functional modules in the power supply circuit as the execution subject.

[0048] See Figure 1 and Figure 2 The power supply circuit control method includes steps 210 to 230, as follows:

[0049] Step 210: Upon receiving a power supply command, control the first switch module to be turned on while keeping the second switch module off, so that the AC source is output to the DC bus after passing through the first switch module, the current limiting module, and the AC / DC conversion module, and charges the bus capacitor.

[0050] Specifically, the control module can output a drive signal to drive the first switch module 120 to conduct. When the second switch module 130 is a drive-on type switch structure, that is, when the second switch module 130 does not receive a conduction signal, it will be in the off state. At this time, the control module does not need to drive the second switch module 130 and will not change the state of the second switch module 130, thereby keeping the second switch module 130 in the off state.

[0051] In another embodiment, the control module in the power supply circuit 100 may also output a drive signal to keep the second switch module 130 in the off state, thereby ensuring that the second switch module 130 is in the off state.

[0052] In this embodiment, by controlling the first switch module 120 to be on while keeping the second switch module 130 off, the AC source 200 charges the bus capacitor 150 and outputs power after passing through the current limiting module 140, the first switch module 120, and the AC / DC conversion module 110 in sequence. Since the current limiting module 140 limits the AC power supplied by the AC source 200, it can prevent the AC power supplied by the AC source 200 from causing a large current surge to the power supply circuit 100.

[0053] Specifically, such as Figure 1 In the circuit structure shown, when the first switch module 120 is turned on and the second switch module 130 is turned off, the AC source 200, the first switch module 120, the current limiting module 140, the AC / DC converter module 110, and the bus capacitor 150 form a power supply loop. The AC power provided by the AC source 200 is output to the AC / DC converter module 110 after passing through the current limiting module 140 and the first switch module 120. The AC / DC converter module 110 performs AC-DC conversion on the input AC power, that is, converts the AC power into DC power, and outputs DC power to the bus capacitor 150 for charging through the DC bus (BUS+, BUS-). At the same time, the output terminal of the AC / DC converter module 110 is also connected to the subsequent circuit through the DC bus (BUS+, BUS-), so the DC power output by the AC / DC converter module 110 can provide power to the subsequent circuit. At this time, since the control module does not drive the boost circuit in the AC / DC conversion module 110, the AC / DC conversion module 110 is only used to convert the AC power after current limiting by the current limiting module 140 into AC-DC power, and then output the converted DC power to the bus capacitor 150 and the subsequent circuit through the DC bus (BUS+, BUS-).

[0054] In all embodiments of this application, when the AC / DC conversion module 110 charges the bus capacitor 150 through the DC bus (BUS+, BUS-), the voltage of the bus capacitor 150 increases with the charging time and eventually reaches the target voltage value, i.e., tends to a steady state. When the voltage of the bus capacitor 150 reaches the target voltage value, in order to avoid the bus capacitor 150 being burned out, the AC / DC conversion module 110 stops charging the bus capacitor 150 through the DC bus (BUS+, BUS-). However, since the DC bus (BUS+, BUS-) is still connected to the subsequent circuit and the subsequent circuit is working normally, in order to ensure the normal operation of the subsequent circuit, the electrical energy stored in the bus capacitor 150 is consumed to provide the working voltage for the subsequent circuit, so that the voltage of the DC bus (BUS+, BUS-) will not be pulled down instantaneously, thereby stabilizing the DC bus (BUS+, BUS-).

[0055] After the converted DC power is output to bus capacitor 150 via the DC bus (BUS+, BUS-), bus capacitor 150 is charged under the action of this DC power. The control module monitors the voltage of bus capacitor 150 to determine its charging status. In practice, sampling the voltage of bus capacitor 150 can be achieved by setting up an existing sampling circuit between bus capacitor 150 and the control module.

[0056] For example, a sampling unit composed of sampling resistors can be used to sample the voltage of the bus capacitor 150, and then the sampled electrical signal can be amplified by an amplification unit and provided to the control module so that the control module can monitor the voltage of the bus capacitor 150.

[0057] It is easy to understand that, in specific implementation, the control module can also use other existing methods to monitor the voltage of the bus capacitor 150, such as voltage sensors, etc., which are not limited here.

[0058] Step 220: When the voltage of the bus capacitor is detected to be greater than the first preset voltage, the AC / DC conversion module is driven to convert the AC power limited by the current limiting module and output it to the DC bus, and to charge the bus capacitor.

[0059] Combination Figure 1 In this embodiment, the first preset voltage can be set as needed. The first preset voltage needs to ensure that there is no excessive voltage difference in the circuit when the second switch module 130 is turned on, so as to avoid the inrush current caused by the voltage difference.

[0060] In this embodiment, since the AC / DC conversion module 110 is not driven during the first pre-charge stage, it only performs the AC / DC conversion function, which is achieved using the rectifier bridge in the AC / DC conversion module 110. When the rectifier bridge is composed of MOSFETs, it can be constructed using the body diodes of the MOSFETs. Specifically, the first preset voltage is lower than the voltage of the AC power supplied by the AC source 200 by a preset value. For example, this preset value can be 30V.

[0061] It should be noted that when the voltage of the bus capacitor 150 is less than or equal to the first preset voltage, the AC / DC conversion module 110 is not driven. Therefore, the AC power provided by the AC source 200 passes through the current limiting module 140, the first switching module 120 and the AC / DC conversion module 110 to the bus capacitor 150 in sequence.

[0062] Specifically, when the first switch module 120 is turned on, the AC source 200, current limiting module 140, first switch module 120, AC / DC conversion module 110, and bus capacitor 150 form a pre-charging circuit. This pre-charging circuit is used to pre-charge the bus capacitor 140, enabling the voltage of the bus capacitor 150 to reach a certain value. When the voltage of the bus capacitor 150 is greater than a first preset voltage, a control signal is sent to the AC / DC conversion module 110. This control signal drives the AC / DC conversion module 110 to convert the AC power limited by the current limiting module 140 to charge the bus capacitor 150 and output it. This process further boosts the voltage of the bus capacitor 150, achieving a further voltage boost operation for the bus capacitor 150.

[0063] It is understood that in all embodiments of this application, the first switch module 120 is kept in the on state whether the voltage of the bus capacitor 150 is detected to be less than or equal to the first preset voltage or the voltage of the bus capacitor 150 is detected to be greater than the first preset voltage.

[0064] Figure 3 A specific structural block diagram of a power supply circuit provided in one embodiment of this application is shown. For example... Figure 3 As shown, in one embodiment of this application, the AC / DC conversion module 110 includes a rectifier unit 111, an energy storage unit 112, and a switching unit 113. The first terminal of the rectifier unit 111 is connected to the first terminal of the energy storage unit 112, the second terminal of the energy storage unit 112 is connected to the first terminal of the switching unit 113, and the second terminal of the switching unit 113 is connected to the second terminal of the rectifier unit 111. The switching unit 113 is connected in parallel with a bus capacitor 150. When the voltage of the bus capacitor 150 is greater than a first preset voltage, a control signal is sent to the switching unit 113 in the AC / DC conversion module 110. This control signal controls the switching of the switching unit 113 at a certain frequency. When switch unit 113 is turned on, AC source 200, current limiting module 140, first switch module 120, rectifier unit 111, energy storage unit 112, and switch unit 113 form a circuit. Rectifier unit 111 converts the AC power limited by current limiting module 140 and supplies it to energy storage unit 112 for charging. Bus capacitor 150 cannot be charged because it is short-circuited. When switch unit 113 is turned off, AC source 200, current limiting module 140, first switch module 120, rectifier unit 111, energy storage unit 112, and bus capacitor 150 form a circuit. The DC power output by rectifier unit 111 after converting the AC power limited by current limiting module 140, together with the freewheeling discharge of energy storage unit 112, charges bus capacitor 150, thereby boosting the voltage of bus capacitor 150.

[0065] Step 230: When the voltage of the bus capacitor is detected to be greater than the second preset voltage, control the second switch module to turn on and control the first switch module to turn off, and control the AC / DC conversion module according to the target power supply voltage of the subsequent circuit and the input voltage of the AC source to output the target power supply voltage; wherein the second preset voltage is greater than the first preset voltage and the second preset voltage is greater than the voltage of the AC source.

[0066] Specifically, after the AC / DC conversion module 110 converts the AC power limited by the current limiting module 140 to charge the bus capacitor 150, the voltage of the bus capacitor 150 continuously increases. When the voltage of the bus capacitor 150 is detected to be greater than the second preset voltage, the second switch module 130 is controlled to turn on, and the first switch module 120 is controlled to turn off. Then, the connection line between the AC source 200 and the AC / DC conversion module 110 will be switched from the line of the first switch module 120 to the line of the second switch module 130. That is, the AC source 200, the second switch module 130, the AC / DC conversion module 110, and the bus capacitor 150 form a charging circuit. At this time, according to the target supply voltage and the voltage of the AC source 200, the AC / DC conversion module 110 is controlled to convert the voltage of the AC source 200 to output the target supply voltage.

[0067] It should be noted that the target supply voltage refers to the voltage value required by the subsequent circuits, and is also the target voltage value that the bus capacitor 150 is configured to reach during the charging process. The target supply voltage is not the maximum charging voltage value of the bus capacitor 150. In practical applications, the magnitude of this target supply voltage can be determined according to the voltage requirements of the subsequent circuits and the energy storage capacity of the bus capacitor 150, and is not limited here.

[0068] In this embodiment, the power supply circuit formed by AC source 200, first switch module 120, current limiting module 140, AC / DC conversion module 110, and bus capacitor 150 is a soft-start power supply circuit, while the charging circuit formed by AC source 200, second switch module 130, AC / DC conversion module 110, and bus capacitor 150 is the main power supply circuit. Since the second preset voltage is greater than the voltage of AC source 200, when switching from the soft-start power supply circuit to the main power supply circuit, the voltage of bus capacitor 150 is already greater than the voltage of the AC power supplied by AC source 200. Therefore, no positive voltage drop will form from AC source 200 to bus capacitor 150, thus preventing a significant impact on bus capacitor 150 after the switch.

[0069] In one embodiment of this application, before step 210, a validity detection step for the AC source is further included, specifically:

[0070] The voltage of the AC source is detected to determine whether the voltage of the AC source is a valid voltage; when it is determined that the voltage of the AC source is a valid voltage, the steps of controlling the first switch module to turn on and controlling the second switch module to turn off are executed.

[0071] Specifically, the effectiveness detection of the AC source actually involves detecting the voltage of the AC source 200 to determine whether the AC source 200 is compatible with the power supply circuit 100 for operation. When the voltage of the AC source 200 is an effective voltage, it indicates that the AC source 200 is a valid power supply and can provide effective AC power to the power supply circuit 100. Therefore, after connecting the AC source 200, the power supply circuit 100 can obtain effective input AC power and then execute step 210 to pre-charge the bus capacitor 150. When the voltage of the AC source 200 is not an effective voltage, it indicates that the AC source 200 is not compatible with the operating requirements of the power supply circuit 100. For example, the AC source 200 may be damaged, or the AC power output from the AC source 200 may not be suitable for the power supply circuit 100.

[0072] Understandably, when it is determined that the voltage of the AC source is not an effective voltage, the steps of controlling the first switch module to turn on and controlling the second switch module to turn off are prohibited.

[0073] This embodiment detects the voltage of the AC source, and only executes the steps of controlling the first switch module 120 to conduct and the second switch module 130 to disconnect when it is determined that the voltage of the AC source 200 is an effective voltage. This avoids the risk of failure or damage to the power supply circuit 100 when the AC voltage provided by the AC source 200 is unstable or incompatible with the power supply circuit 100, and further improves the safety and reliability of the power supply circuit 100.

[0074] It is easy to understand that, in practical applications, alternating current (AC) usually includes two parameters: voltage value and voltage frequency. Therefore, it is possible to determine whether an AC source can output an effective voltage by detecting these two parameters.

[0075] In one embodiment of this application, the step of detecting the voltage of the AC source described above may include:

[0076] The system detects whether the effective voltage value of the AC source is within a preset voltage range and whether the voltage frequency of the AC source is within a preset frequency range. When the effective voltage value of the AC source is within the preset voltage range and the voltage frequency of the AC source is within the preset frequency range, the voltage of the AC source is determined to be an effective voltage. When the effective voltage value of the AC source is not within the preset voltage range, or when the voltage frequency of the AC source is not within the preset frequency range, the voltage of the AC source is determined to be an ineffective voltage.

[0077] Specifically, the effective voltage value and voltage frequency of the AC power output by AC source 200 are detected respectively. When the effective voltage value of the AC power output by AC source 200 is within the preset voltage range and the voltage frequency of AC source 200 is within the preset frequency range, it can be considered that AC source 200 can output effective voltage.

[0078] In this embodiment, the preset voltage range and preset frequency range are voltage and frequency ranges adapted to the AC power required by the power supply circuit 100. When either the effective voltage value or the voltage frequency of the AC power output by the AC source 200 does not meet the corresponding condition, that is, the effective voltage value of the AC source 200 is not within the preset voltage range, or the voltage frequency of the AC source 200 is not within the preset frequency range, then the voltage output by the AC source 200 is considered not to be an effective voltage.

[0079] It is easy to understand that, in specific applications, the voltage range and frequency range that can be adapted to the power supply circuit 100 can be configured as preset voltage range and preset frequency range according to the specifications of the AC source 200 or the actual working requirements of the power supply circuit 100.

[0080] For example, the AC power required by the power supply circuit 100 has an effective voltage value of Y1 to Y2 (V) and a voltage frequency of Z1 to Z2 (Hz), that is, a preset voltage range of Y1 to Y2 (V) and a preset frequency range of Z1 to Z2 (Hz). Therefore, if the AC power supplied by the AC source 200 meets the condition that the effective voltage value is within the range of Y1 to Y2 (V) and the voltage frequency is within the range of Z1 to Z2 (Hz), then the voltage of the AC source 200 is considered to be an effective voltage. If either of these two conditions is not met, then the voltage of the AC source 200 is considered not to be an effective voltage.

[0081] In one embodiment of this application, after controlling the first switch module 120 to be turned on and keeping the second switch module 130 in the off position, and before step S220, a short-circuit detection can be performed on the output terminal of the AC / DC conversion module 110 to ensure that the subsequent circuit connected to the power supply circuit 100 is in normal working condition. The specific steps include:

[0082] When the conduction time of the first switching module reaches the preset time, a short circuit detection is performed on the AC / DC conversion module; when it is determined that the AC / DC conversion module is not short-circuited, it is detected whether the voltage of the bus capacitor is greater than the first preset voltage.

[0083] Specifically, after briefly turning on the first switch module 120, a short circuit detection is performed on the AC / DC conversion module 110. When it is detected that the AC / DC conversion module 110 is not short-circuited, the first switch module 120 remains in the on state. The AC power provided by the AC source 200 charges the bus capacitor 150 after passing through the current limiting module 140 and the AC / DC conversion module 110, causing the voltage of the bus capacitor 150 to rise until it reaches the first preset voltage, and then step 220 is executed.

[0084] In this embodiment, when short-circuit detection is performed on the AC / DC converter module, the preset duration for which the first switch module 120 is turned on is determined based on the power and heat loss that the current limiting module 140 can withstand. When the AC / DC converter module 110 is short-circuited, a large current will be generated in the circuit. This large current will cause the current limiting module 140 to generate significant power and heat loss. The longer the preset duration is set, the greater the heat loss of the current limiting module 140 will be. Therefore, the preset duration should be set to ensure that the heat loss generated by the current limiting module 140 within the preset duration is within the heat loss range that the current limiting module 140 can withstand. Otherwise, when the actual heat loss generated by the current limiting module 140 exceeds its heat loss tolerance, the current limiting module 140 will be burned out.

[0085] It is understandable that when a short circuit is detected in the AC / DC conversion module 110, in order to ensure the safety of the circuit and avoid damage to the components in the circuit, the first switch module 120 is disconnected, causing the power supply circuit 100 to stop working. In this case, a short circuit warning message can also be generated so that the cause of the short circuit can be analyzed based on the warning message. After the short circuit fault is repaired, step 210 is executed again.

[0086] In one embodiment of this application, the specific steps for short-circuit detection of the AC / DC conversion module 110 include:

[0087] The system detects whether the output voltage of the AC / DC converter module is lower than a preset voltage threshold. If the output voltage of the AC / DC converter module is lower than the preset voltage threshold, the AC / DC converter module is determined to be short-circuited. If the output voltage of the AC / DC converter module is higher than the preset voltage threshold, the AC / DC converter module is determined to be not short-circuited.

[0088] Combination Figure 1If the AC / DC converter module 110 is short-circuited, it is essentially short-connected, resulting in a very low output voltage. Therefore, detecting the output voltage of the AC / DC converter module 110 can confirm whether it is short-circuited. If the output voltage of the AC / DC converter module 110 is lower than a preset voltage threshold, it indicates a short circuit, and the first switch module 120 needs to be disconnected. If the output voltage of the AC / DC converter module 110 is higher than the preset voltage threshold, it indicates that the AC / DC converter module 110 is not short-circuited. In this case, the first switch module 120 remains on to pre-charge the bus capacitor 150.

[0089] It is understandable that when the output voltage of the AC / DC converter module 110 is equal to the preset voltage threshold, since the output voltage of the AC / DC converter module 110 is not less than the preset voltage threshold, it can be determined that the AC / DC converter module is not short-circuited.

[0090] For example, during the short-circuit detection process of the AC / DC converter module 110, the output voltage of the AC / DC converter module 110 is sampled after the on-time of the first switching module 120 reaches N (ms). If the output voltage of the AC / DC converter module 110 is less than 10% of the amplitude of the AC power supplied by the AC source 200, then the AC / DC converter module 110 is considered to be short-circuited. Assuming the AC source 200 supplies X (V) of AC power, its amplitude is... The preset voltage threshold is In other words, after the conduction time of the first switching module 120 reaches N (ms), the measured output voltage of the AC / DC conversion module 110 is greater than... If the AC / DC converter module 110 is not short-circuited, then the AC / DC converter module 110 is not short-circuited; otherwise, the AC / DC converter module 110 is short-circuited.

[0091] Figure 4 The schematic diagram illustrates a structural block diagram of a power supply circuit provided in one embodiment of this application, which can implement the control method of the power supply circuit provided in any embodiment of this application.

[0092] like Figure 4As shown, the power supply circuit 100 used in this embodiment includes: an AC / DC conversion module 110, a first switching module 120, a second switching module 130, a current limiting module 140, a bus capacitor 150, and a control module 160. The output terminal of the AC / DC conversion module 110 is connected to the DC bus (BUS+, BUS-) to connect to the subsequent circuit (not shown in the figure). The bus capacitor 150 is connected in parallel between the positive and negative terminals of the DC bus (BUS+, BUS-). The second switching module 130 is used to connect the AC source 200 and the AC / DC conversion module 110. The first switching module 120 and the current limiting module 140 are connected in series and then in parallel across the second switching module 130. The control module 160 is connected to the AC / DC conversion module 110, the first switching module 120, the second switching module 130, and the bus capacitor 150.

[0093] The control module 160 is used to control the first switch module 120 to be turned on and keep the second switch module 130 in the off state when a power supply command is received, so that the AC source 200 is output to the DC bus after passing through the first switch module 120, the current limiting module 140 and the AC / DC conversion module 110, and charges the bus capacitor 150.

[0094] The control module 160 is also used to drive the AC / DC conversion module 110 to convert the AC power limited by the current limiting module 140 to charge the bus capacitor 150 and output it when the voltage of the energy storage module 150 is detected to be greater than the first preset voltage.

[0095] The control module 160 is also used to control the second switch module 130 to turn on and the first switch module 120 to turn off when the voltage of the bus capacitor 150 is detected to be greater than the second preset voltage, and to control the AC / DC conversion module 110 according to the target power supply voltage of the subsequent circuit and the voltage of the AC source 200 to output the target power supply voltage; wherein the second preset voltage is greater than the first preset voltage and the second preset voltage is greater than the voltage of the AC source.

[0096] The specific implementation process and details of the relevant functions of the control module 160 have been described in detail in the corresponding embodiments, and will not be repeated here.

[0097] It is understood that, in the specific implementation of the power supply circuit 100 provided in this embodiment, the AC / DC conversion module 110 can also be selected as... Figure 3 The specific structure of the AC / DC conversion module 110. For example... Figure 3 As shown, the AC / DC conversion module 110 may include a rectifier unit 111, an energy storage unit 112, and a switching unit 113.

[0098] The first input terminal of rectifier unit 111 is connected to the first switch module 120 and the second switch module 130, respectively. The second input terminal of rectifier unit 111 is used to connect to the neutral terminal of AC source 200. The first output terminal of rectifier unit 111 is connected to the first terminal of energy storage unit 112, and the second output terminal of rectifier unit 111 is connected to the second output terminal of AC / DC converter module 110. The second terminal of energy storage unit 112 is connected to the first output terminal of AC / DC converter module 110. The first terminal of switch unit 113 is connected to the first output terminal of AC / DC converter module 110, and the second terminal of switch unit 113 is connected to the second output terminal of AC / DC converter module 110.

[0099] Here, due to the specific connection relationship between the rectifier unit 111, the energy storage unit 112, and the switching unit 113... Figure 3 The corresponding implementation examples have been described in detail, so they will not be repeated here.

[0100] by Figure 4 Based on the specific structural block diagram of the provided power supply circuit, Figure 5 A schematic diagram of a power supply circuit provided in one embodiment of this application is shown.

[0101] For example, taking AC source 200 as AC mains power, the live wire L of AC mains power is used to connect to the first input node in power supply circuit 100, and the neutral wire N of AC mains power is used to connect to the second input node in power supply circuit 100.

[0102] Combination Figure 4 and Figure 5 The first switching module 120 includes a first relay S1. The current limiting module 140 includes a current limiting resistor R. The second switching module 130 includes a second relay S2. The bus capacitor 150 includes an energy storage capacitor C. The AC / DC conversion module 110 includes a rectifier bridge 111, an inductor L, and a switching transistor Q.

[0103] The first input terminal of rectifier bridge 111 is connected in series with the second switching module 130, that is, the first input terminal of rectifier bridge 111 is connected in series with the second relay S2 to connect to the live wire L terminal of AC source 200. The second input terminal of rectifier bridge 111 is used to connect to the neutral wire N terminal of AC source 200. The first output terminal of rectifier bridge 111 is connected to the first terminal of inductor L, and the second output terminal of rectifier bridge 111 is connected to the second terminal q2 of switching transistor Q. The second terminal of inductor L is connected to the first terminal q1 of switching transistor Q. The control terminal q3 of switching transistor Q is connected to control module 160. The first terminal q1 of switching transistor Q is also connected to the first output terminal of AC / DC conversion module 110, and the second terminal q2 of switching transistor Q is also connected to the second output terminal of AC / DC conversion module 111.

[0104] In practical implementation, the control module 160 can use an existing MCU (Microcontroller Unit). Figure 5 (Not shown in the text) The connection relationship between the control module 160 and other modules and its related functions can be referred to the description of the foregoing embodiments, and will not be repeated here.

[0105] like Figure 5 As shown, the first end of the current-limiting resistor R serves as the first input node in the power supply circuit 100, used to connect to the live wire L of the AC mains power. The first end of the first relay S1 is connected to the second end of the current-limiting resistor R, the second end of the first relay S1 is connected to the first end of the second relay S2, and the second end of the second relay S2 is connected to the first end of the current-limiting resistor R.

[0106] exist Figure 5 In this rectifier bridge 111, there are four diodes: D2, D3, D4, and D5. The anode of D2 and the cathode of D3 are connected to the second terminal of the first relay S1. The node formed by connecting the cathodes of D2 and D4 serves as the first output terminal of the rectifier bridge 111 and is connected to the first terminal of the inductor L. The anode of D4 and the cathode of D5 are connected to the neutral line N of the AC mains. The node formed by connecting the anodes of D3 and D5 serves as the second output terminal of the rectifier bridge and is connected to the second terminal q2 of the switch Q. The second terminal of the inductor L and the first terminal q1 of the switch Q are connected to the first terminal of the energy storage capacitor C. The second terminal of the energy storage capacitor C is connected to the second terminal of the switch Q.

[0107] In practical implementation, the switching transistor Q can be a switching device that can be turned on or off according to a control signal, such as a transistor, a field-effect transistor, etc. The first terminal q1 of the switching transistor Q and the first terminal of the energy storage capacitor C are connected to the positive terminal BUS+ of the DC bus. The second terminal q2 of the switching transistor Q and the second terminal of the energy storage capacitor C are connected to the negative terminal BUS- of the DC bus. The second terminal q2 of the switching transistor Q is also connected to the second output terminal of the rectifier bridge 111. The switching unit Q also has a control terminal q3, which can be connected to the control module 160 to receive control signals from the control module 160, and turn on the first terminal q1 and the second terminal q2 of the switching transistor Q according to the control signals.

[0108] like Figure 5 As shown, the power supply circuit 100 also includes a surge protection diode D1, the positive terminal of which is connected to the second terminal of the second relay S2, and the negative terminal of which is connected to the output node O.

[0109] Combination Figure 4 and Figure 5Taking a 200-bit AC mains power source as an example, the working principle of the power supply circuit 100 provided in this embodiment is explained as follows. The control module 160 controls the first relay S1 to be turned on and the second relay S2 to be turned off. At this time, the AC mains power, the current limiting resistor R, the first relay S1, the rectifier unit 111, the inductor L and the energy storage capacitor C form a circuit. The AC power provided by the AC mains power precharges the energy storage capacitor C through the current limiting resistor R, the first relay S1, the rectifier unit 111 and the inductor L.

[0110] Before the control module 160 controls the first relay S1 to turn on, the control module 160 can also perform validity detection on the voltage of the AC power supplied by the mains AC. For details, please refer to the relevant description in the previous method embodiment, which will not be repeated here.

[0111] During the pre-charging process of the energy storage capacitor C, when the control module 160 detects that the voltage of the energy storage capacitor C is greater than the first preset voltage, the control module 160 drives the AC / DC conversion module 110 to convert the AC power limited by the current limiting resistor R to charge the energy storage capacitor C and output it.

[0112] Specifically, the control module 160 outputs a control signal to the control terminal q3 of the switching transistor Q. This control signal is used to control the switching transistor Q to turn on and off at a certain frequency. When the switching transistor Q is on, the energy storage capacitor C is short-circuited. The AC mains power, the current-limiting resistor R, the first relay S1, the rectifier unit 111, the inductor L, and the switching transistor Q form a circuit. The rectifier unit 111 converts the AC power limited by the current-limiting resistor R and supplies it to the inductor L to charge. The energy storage capacitor C cannot be charged because it is short-circuited. When the switching transistor Q is off, the AC mains power, the current-limiting resistor R, the first relay S1, the rectifier unit 111, the inductor L, and the energy storage capacitor C form a circuit. The DC power output by the rectifier unit 111 after converting the AC power limited by the current-limiting resistor R, together with the freewheeling discharge of the inductor L, charges the energy storage capacitor C, thereby boosting the voltage of the energy storage capacitor C.

[0113] Before detecting whether the voltage of the energy storage capacitor C is greater than the first preset voltage, the control unit 160 can also perform short-circuit detection on the AC / DC conversion module 110. For details, please refer to the relevant description in the previous method embodiment, which will not be repeated here.

[0114] During the voltage boosting process of the energy storage capacitor C, when the control unit 160 detects that the voltage of the energy storage capacitor C is greater than the second preset voltage, the control unit 160 controls the second relay S2 to conduct and controls the first relay S1 to disconnect, completing the switching of the charging circuit. The AC source AC, the second relay S2, the AC / DC conversion module 110, and the energy storage capacitor C form a charging circuit. Since the second preset voltage is greater than the voltage of the AC source AC, no forward voltage drop will be generated across the surge protection diode D1 after the switch is switched. This ensures that the surge protection diode D1 is reverse cut off after the switch is switched, preventing the surge protection diode D1 from burning out due to a large current flowing through it, reducing the failure rate of the power supply circuit, and improving the overall reliability of the power supply circuit.

[0115] After switching the switch, the AC / DC conversion module 110 is regulated according to the target power supply voltage, so that the AC / DC conversion module 110 converts the voltage of the AC source AC and outputs the target power supply voltage.

[0116] In one embodiment of this application, Figure 6 schematically shown Figure 5 The diagram shows the timing sequence of the power supply circuit. Figure 6 As shown, at time t1, controller 16 controls the first relay S1 to turn on and the second relay S2 to turn off, allowing the energy storage capacitor C to pre-charge, and the voltage of the energy storage capacitor C (that is, the voltage of the output node O) to continuously increase. When the voltage value of the energy storage capacitor C is detected to be greater than the first preset voltage, the AC / DC conversion module 110 is driven, that is, a control signal is sent to the switching transistor Q. Here, the first preset voltage can be the amplitude of the AC mains voltage. For example, if the AC mains provides 220V alternating current, its amplitude is...

[0117] exist Figure 6 In the process, at time t2, the voltage of the energy storage capacitor C is greater than 310V, sending a control signal to the switching transistor Q, causing the voltage of the energy storage capacitor C to continue to rise. After time t2, the voltage of the energy storage capacitor C is detected to determine whether it has reached the second preset voltage. At time t3, if the voltage of the energy storage capacitor C is detected to be greater than the second preset voltage, a switching operation is performed, i.e., the first relay S1 is deactivated and the second relay S2 is activated. The second preset voltage is greater than the AC mains voltage, for example, set to 360V. After the second relay S2 is activated, the voltage of the output node O can be controlled to reach the target supply voltage, for example, the target supply voltage is 450V.

[0118] In another embodiment of this application, in order to prevent reverse current flow, the power supply circuit 100 also includes a reverse protection diode.

[0119] Figure 7A schematic diagram of a power supply circuit provided in another embodiment of this application is shown. For example... Figure 7 As shown, in order to prevent reverse current flow, the power supply circuit 100 also includes a reverse protection diode D6.

[0120] exist Figure 7 In the circuit, the positive terminal of the anti-reverse diode D6 is connected to the first terminal q1 of the switching transistor Q, and the negative terminal of the anti-reverse diode D6 is connected to the first output terminal of the AC / DC conversion module 110.

[0121] Figure 8 A schematic block diagram of an energy storage device provided in one embodiment of this application is shown.

[0122] like Figure 8 As shown, the energy storage device 800 includes a battery module 810 and a power supply circuit 100.

[0123] In this embodiment, the power supply circuit 100 can be any power supply circuit 100 provided in any embodiment of this application. The battery module 810 serves as the downstream circuit of the power supply circuit 100, and the power supply circuit 100 can charge the battery module 810 according to the control method of the power supply circuit provided in any implementation of this application. It should be noted that since the battery module 810 is a downstream circuit of the power supply circuit 100, charging the battery module 810 can be achieved directly using the voltage on the DC bus (BUS+, BUS-), or a DC / DC converter module can be added between the battery module 810 and the DC bus (BUS+, BUS-). This DC / DC converter module can then convert the voltage on the DC bus (BUS+, BUS-) and output it to the battery module 810 for charging.

[0124] It is easy to understand that, in actual implementation, the DC / DC conversion module can be implemented using existing LLC circuits, which will not be elaborated here.

[0125] The energy storage device provided in this application embodiment can avoid damage to components in the circuit caused by a large voltage difference during the switching of the power supply circuit 100, making the charging process of the battery module 810 more stable and reducing the failure rate of the energy storage device.

[0126] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0127] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A control method of a power supply circuit, characterized by, The power supply circuit comprises an AC / DC conversion module, a first switch module, a second switch module, a current limiting module and a bus capacitor, an output end of the AC / DC conversion module is connected to a DC bus to be connected to a subsequent circuit, the bus capacitor is connected in parallel between positive and negative poles of the DC bus, the second switch module is used to connect an AC source and the AC / DC conversion module, the first switch module and the current limiting module are connected in series and then connected in parallel across the second switch module, and the control method comprises: when a power supply instruction is received, the first switch module is controlled to be turned on, the second switch module is kept off, and the AC / DC conversion module is not driven, so that the AC source is output to the DC bus after passing through the first switch module, the current limiting module and the AC / DC conversion module, and the bus capacitor is charged; when it is detected that the voltage of the bus capacitor is greater than a first preset voltage, the first switch module is kept in the on state, the second switch module is kept in the off state, and the AC / DC conversion module is driven to convert the AC power after current limiting of the current limiting module and then output to the DC bus to charge the bus capacitor; when it is detected that the voltage of the bus capacitor is greater than a second preset voltage, the second switch module is controlled to be turned on, the first switch module is controlled to be turned off, and the AC / DC conversion module is controlled to output a target power supply voltage of the subsequent circuit according to the target power supply voltage and an input voltage of the AC source; wherein the second preset voltage is greater than the first preset voltage, and the second preset voltage is greater than the voltage of the AC source; the first preset voltage is less than the voltage of the AC power provided by the AC source.

2. The control method of a power supply circuit according to claim 1, characterized by, Before the step of driving the AC / DC conversion module to convert the AC power after current limiting of the current limiting module and then output to the DC bus to charge the bus capacitor when it is detected that the voltage of the bus capacitor is greater than the first preset voltage, the method further comprises: when the on duration of the first switch module reaches a preset duration, short circuit detection is performed on the AC / DC conversion module; when it is determined that the AC / DC conversion module is not short-circuited, it is detected whether the voltage of the bus capacitor is greater than the first preset voltage.

3. The control method of a power supply circuit according to claim 2, characterized by, The short circuit detection on the AC / DC conversion module comprises: detecting whether the output end voltage of the AC / DC conversion module is lower than a preset voltage threshold; when the output end voltage of the AC / DC conversion module is lower than the preset voltage threshold, it is determined that the AC / DC conversion module is short-circuited; when the output end voltage of the AC / DC conversion module is greater than the preset voltage threshold, it is determined that the AC / DC conversion module is not short-circuited.

4. The control method of a power supply circuit according to claim 2, characterized by After the short circuit detection on the AC / DC conversion module, the method further comprises: when it is determined that the AC / DC conversion module is short-circuited, the first switch module is controlled to be turned off.

5. The control method of a power supply circuit according to claim 1, characterized by Before the step of controlling the first switch module to be turned on and keeping the second switch module off when a power supply instruction is received, the method further comprises: detecting a voltage of the AC power source to determine whether the voltage of the AC power source is a valid voltage; when it is determined that the voltage of the AC power source is a valid voltage, performing the step of controlling the first switch module to be turned on and keeping the second switch module to be turned off when a power supply instruction is received.

6. The control method of a power supply circuit according to claim 5, wherein The step of detecting the voltage of the AC power source to determine whether the voltage of the AC power source is a valid voltage comprises: detecting whether a voltage effective value of the AC power source is within a preset voltage range and detecting whether a voltage frequency of the AC power source is within a preset frequency range; when the voltage effective value of the AC power source is within the preset voltage range and the voltage frequency of the AC power source is within the preset frequency range, determining that the voltage of the AC power source is a valid voltage; when the voltage effective value of the AC power source is not within the preset voltage range or the voltage frequency of the AC power source is not within the preset frequency range, determining that the voltage of the AC power source is not a valid voltage.

7. A power supply circuit, characterized by comprising: comprises: an AC / DC conversion module, a first switch module, a second switch module, a current limiting module, a bus capacitor and a control module; an output end of the AC / DC conversion module is connected to a DC bus to be connected to a subsequent circuit; the bus capacitor is connected in parallel between positive and negative poles of the DC bus; the second switch module is used to connect the AC power source and the AC / DC conversion module; the first switch module and the current limiting module are connected in series and then connected in parallel across the second switch module; the control module is used to control the first switch module to be turned on and keep the second switch module to be turned off when a power supply instruction is received, so that the AC power source is output to the DC bus through the first switch module, the current limiting module and the AC / DC conversion module, and the bus capacitor is charged; the control module is further used to drive the AC / DC conversion module to output the AC power after current limiting by the current limiting module to the DC bus and charge the bus capacitor when it is detected that the voltage of the bus capacitor is greater than a first preset voltage; the control module is further used to control the second switch module to be turned on and control the first switch module to be turned off when it is detected that the voltage of the bus capacitor is greater than a second preset voltage, and control the AC / DC conversion module according to a target power supply voltage of the subsequent circuit and the voltage of the AC power source to output the target power supply voltage; wherein the second preset voltage is greater than the first preset voltage and the second preset voltage is greater than the voltage of the AC power source.

8. The power supply circuit of claim 7, wherein, The AC / DC conversion module comprises a rectifier bridge, an inductor and a switch tube; a first input end of the rectifier bridge is connected in series with the second switch module to be connected to a live line end of the AC power source; a second input end of the rectifier bridge is used to connect a neutral line end of the AC power source; a first output end of the rectifier bridge is connected to a first end of the inductor; and a second output end of the rectifier bridge is connected to a second end of the switch tube; a second end of the inductor is connected to a first end of the switch tube; and a control end of the switch tube is connected to the control module. The first end of the switch tube is also connected to the first output end of the AC / DC conversion module, and the second end of the switch tube is also connected to the second output end of the AC / DC conversion module.

9. The power supply circuit of claim 8, wherein, The AC / DC conversion module further comprises an anti-reverse diode, the positive electrode of the anti-reverse diode being connected to the first end of the switch tube, and the negative electrode of the anti-reverse diode being connected to the first output end of the AC / DC conversion module.

10. An energy storage device, characterized by, The power supply circuit comprises a battery module and the power supply circuit according to any one of claims 7-9, and the battery module is a subsequent circuit of the power supply circuit.

Images