Battery access control circuit and hybrid inverter

Abstract

The utility model provides a battery access control circuit and a hybrid inverter, the battery access control circuit is arranged in the hybrid inverter, the input end of the battery access control circuit is connected to a battery access port of the hybrid inverter, and the output end of the battery access control circuit is connected to a charging and discharging system. The battery access control circuit is connected to the battery port of the inverter to detect the insulation resistance of the positive electrode and the negative electrode of the battery pack to the ground, so that the inverter is protected from being damaged due to the insulation damage of the battery.

Description

Technical Field

[0001] This application relates to the field of electrical technology, and in particular to a battery access control circuit and a hybrid inverter. Background Technology

[0002] In a battery pack, insulation resistance refers to the resistance between the positive and negative terminals of the battery and ground (or the casing). High insulation resistance indicates good electrical isolation, while low insulation resistance suggests the possibility of leakage paths, which could cause current to leak into places where it shouldn't be, thus creating a safety hazard.

[0003] In applications where battery packs are connected to inverters, when the insulation resistance of the battery pack decreases, it can easily cause the inverter's grounding casing to become electrified, resulting in uncontrollable hazards such as personal injury and fire caused by overheating at the fault point. Utility Model Content

[0004] In view of this, the purpose of this application is to provide at least one battery access control circuit and hybrid inverter, which detects the insulation resistance of the positive and negative terminals of the battery pack to ground by connecting the battery access control circuit to the battery port of the inverter, and protects the inverter from damage due to insulation failure of the battery.

[0005] This application mainly includes the following aspects:

[0006] In a first aspect, embodiments of this application provide a battery access control circuit, which is arranged inside a hybrid inverter. The input terminal of the battery access control circuit is connected to the battery access port of the hybrid inverter, and the output terminal of the battery access control circuit is connected to a charging and discharging system.

[0007] In one possible implementation, the battery access control circuit includes an insulation resistance detection module, and the battery access port includes a positive battery access port and a negative battery access port, wherein the insulation resistance detection module is connected in parallel between the positive battery access port and the negative battery access port of the hybrid inverter.

[0008] In one possible implementation, the battery access control circuit further includes a controller, and the insulation detection control terminal of the insulation impedance detection module is connected to the controller.

[0009] In one possible implementation, the battery access control circuit further includes a battery access control switch, wherein a first connection terminal of the battery access control switch is connected to the positive terminal access port of the battery, a second connection terminal of the battery access control switch is connected to one end of the charging and discharging system, the other end of the charging and discharging system is connected to the negative terminal access port of the battery, and a control terminal of the battery access control switch is connected to a controller.

[0010] In one possible implementation, the insulation impedance detection module includes a positive impedance detection unit, wherein a first connection terminal of the positive impedance detection unit is connected to the positive terminal access port of the battery, a second connection terminal of the positive impedance detection unit is connected to the protective ground, and a control terminal of the positive impedance detection unit is connected to the controller.

[0011] In one possible implementation, the positive impedance detection unit includes a first insulation detection switch and a first insulation measurement component, wherein a first connection terminal of the first insulation detection switch is connected to the positive terminal access port of the battery, a second connection terminal of the first insulation detection switch is connected to the protective ground through the first insulation measurement component, and a control terminal of the first insulation detection switch is connected to the controller.

[0012] In one possible implementation, the insulation impedance detection module includes a negative electrode impedance detection unit, wherein a first connection terminal of the negative electrode impedance detection unit is connected to the negative electrode inlet port of the battery, a second connection terminal of the negative electrode impedance detection unit is connected to the protective ground, and a control terminal of the negative electrode impedance detection unit is connected to the controller.

[0013] In one possible implementation, the negative electrode impedance detection unit includes a second insulation detection switch and a second insulation measurement component, wherein the first connection terminal of the second insulation detection switch is connected to the negative electrode access port of the battery, the second connection terminal of the second insulation detection switch is connected to the protective ground through the second insulation measurement component, and the control terminal of the second insulation detection switch is connected to the controller.

[0014] In one possible implementation, the controller is a digital signal processor.

[0015] In one possible implementation, the battery access control circuit further includes a DC-DC converter, wherein a first connection terminal of the DC-DC converter is connected to a second connection terminal of the battery access control switch, the second connection terminal of the DC-DC converter is connected to the negative terminal access port of the battery, a third connection terminal of the DC-DC converter is connected to one end of the charging and discharging system, and a fourth connection terminal of the DC-DC converter is connected to the other end of the charging and discharging system.

[0016] Secondly, this application also provides a hybrid inverter, which has a built-in battery access control circuit as provided in any of the above embodiments, the battery access port of the hybrid inverter is connected to a battery pack, and the output terminal of the hybrid inverter is connected to a power supply load.

[0017] This application provides a battery access control circuit and a hybrid inverter. The battery access control circuit is arranged inside the hybrid inverter. The input terminal of the battery access control circuit is connected to the battery access port of the hybrid inverter, and the output terminal of the battery access control circuit is connected to the charging and discharging system. By connecting the battery access control circuit to the battery port of the inverter, the insulation resistance of the positive and negative terminals of the battery pack to ground is detected, protecting the inverter from damage due to insulation failure of the battery.

[0018] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the structure of a hybrid inverter provided in an embodiment of this application is shown;

[0021] Figure 2 This illustration shows one of the structural schematic diagrams of a battery access control circuit provided in an embodiment of this application;

[0022] Figure 3 This is a second schematic diagram of the structure of a battery access control circuit provided in an embodiment of this application;

[0023] Figure 4 The third schematic diagram shows the structure of a battery access control circuit provided in an embodiment of this application. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0025] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0026] In a battery pack, insulation resistance refers to the resistance between the positive and negative terminals of the battery and ground (or the casing). High insulation resistance means good electrical isolation, while low insulation resistance indicates that there may be a leakage path, which may cause current to leak to places where it should not be, thus creating a safety hazard.

[0027] In applications where battery packs are connected to inverters, a decrease in the insulation resistance of the battery pack can lead to more current leakage through unexpected paths, resulting in leakage current. This not only wastes valuable electrical energy but can also damage the internal circuitry of the inverter. It can easily cause the inverter's grounding casing to become electrified, resulting in personal injury. Furthermore, if the heat generated by the leakage current cannot be dissipated in time, it may cause the internal temperature of the inverter to rise, leading to accelerated component aging, performance degradation, or even permanent damage. In more serious cases, it can even cause fires.

[0028] Furthermore, leakage current generates additional electromagnetic interference, affecting the normal operation of the inverter and other electronic equipment, leading to problems such as signal distortion and malfunction, and affecting the stability and reliability of inverter operation.

[0029] Based on this, this application provides a battery access control circuit and a hybrid inverter. By connecting the battery access control circuit to the battery port of the inverter, the insulation resistance of the positive and negative terminals of the battery pack to ground is detected, protecting the inverter from damage due to battery insulation failure, as detailed below:

[0030] Please see Figure 1 , Figure 1 A schematic diagram of a hybrid inverter provided in an embodiment of this application is shown. Figure 1 As shown, the battery access port of the hybrid inverter provided in this embodiment is connected to the battery pack BAT, the output terminal of the hybrid inverter is connected to the power supply load, the hybrid inverter has a built-in battery access control circuit 1, the input terminal of the battery access control circuit 1 is connected to the battery access port of the hybrid inverter, the output terminal of the battery access control circuit 1 is connected to the charging and discharging system inside the hybrid inverter (not shown in the figure), and the hybrid inverter is also connected to the protective ground PE.

[0031] In one specific embodiment, the hybrid inverter is also connected to a photovoltaic power supply system, which includes multiple photovoltaic power supply devices connected in parallel (M photovoltaic power supply devices as shown in the figure). Each photovoltaic power supply device includes at least one photovoltaic panel and a combiner box, which is used to collect and transmit the DC power generated by at least one photovoltaic panel to the hybrid inverter.

[0032] In another specific embodiment, the power supply load includes, but is not limited to, at least one of the following: Grid (Electric Power Grid), EPS (Emergency Power Supply), and GEN (Generator), such as Figure 1 As shown, the power grid, emergency power system, and generator are connected to different output terminals of the hybrid inverter.

[0033] In a preferred embodiment, please refer to Figure 2 , Figure 2 This illustration shows one of the structural schematic diagrams of a battery access control circuit provided in an embodiment of this application. For example... Figure 2 As shown, the battery access control circuit 1 includes an insulation resistance detection module 11, a controller 12, and a battery access control switch 13. The battery access ports include a battery positive terminal access port BAT+ and a battery negative terminal access port BAT-.

[0034] Preferably, the insulation resistance detection module 11 is connected in parallel between the battery positive terminal input port BAT+ and the battery negative terminal input port BAT- of the hybrid inverter, and the insulation detection control terminal of the insulation resistance detection module 11 is connected to the controller 12.

[0035] In another preferred embodiment, the first connection terminal of the battery access control switch 13 is connected to the positive terminal access port BAT+ of the battery, the second connection terminal of the battery access control switch 13 is connected to one end of the charging and discharging system in the hybrid inverter, the other end of the charging and discharging system is connected to the negative terminal access port BAT- of the battery, and the control terminal of the battery access control switch 13 is connected to the controller 12.

[0036] In one specific embodiment, such as Figure 2 As shown, assuming the positive terminal impedance to ground of battery pack BAT is Rp and the negative terminal impedance to ground of battery pack BAT is Rn, controller 12 detects the positive terminal impedance to ground Rp and the negative terminal impedance to ground Rn of battery pack BAT connected to the hybrid inverter through insulation impedance detection module 11, and controls the connection of battery pack BAT through battery connection control switch 13.

[0037] In one example, this application does not impose specific restrictions on the battery access control switch 13; any signal-controlled device, such as a relay, is acceptable.

[0038] In another example, the controller can be a DSP (Digital Signal Processor).

[0039] In a preferred embodiment, please refer to Figure 3 , Figure 3 This is a second schematic diagram of a battery access control circuit provided in an embodiment of this application. Figure 3 As shown, the insulation resistance detection module 11 includes a positive impedance detection unit 110 and a negative impedance detection unit 111.

[0040] Preferably, the first connection terminal of the positive impedance detection unit 110 is connected to the battery positive terminal access port BAT+, the second connection terminal of the positive impedance detection unit 110 is connected to the protective ground PE, and the control terminal of the positive impedance detection unit 110 is connected to the controller 12.

[0041] Among them, the positive electrode impedance detection unit 110 is used to measure the positive electrode impedance to ground of the battery pack BAT as Rp.

[0042] The first connection terminal of the negative electrode impedance detection unit 111 is connected to the battery negative electrode inlet port BAT-, the second connection terminal of the negative electrode impedance detection unit 111 is connected to the protective ground PE, and the control terminal of the negative electrode impedance detection unit 111 is connected to the controller 12.

[0043] Among them, the negative electrode impedance detection unit 111 is used to measure the negative electrode impedance to ground of the battery pack BAT as Rn.

[0044] like Figure 3 As shown, the battery access control circuit also includes a DC-DC converter 14. The first connection terminal of the DC-DC converter 14 is connected to the second connection terminal of the battery access control switch 13. The second connection terminal of the DC-DC converter 14 is connected to the battery negative terminal access port BAT-. The third connection terminal of the DC-DC converter 14 is connected to one end of the charging and discharging system. The fourth connection terminal of the DC-DC converter 14 is connected to the other end of the charging and discharging system.

[0045] Please see Figure 4 , Figure 4 This is shown as a third schematic diagram of a battery access control circuit according to an embodiment of this application. Figure 4 As shown, the positive impedance detection unit 110 includes a first insulation detection switch K1 and a first insulation measurement component 1101. The first connection terminal of the first insulation detection switch K1 is connected to the battery positive terminal access port BAT+, the second connection terminal of the first insulation detection switch K1 is connected to the protective ground PE through the first insulation measurement component 1101, and the control terminal of the first insulation detection switch K1 is connected to the controller 12.

[0046] Specifically, the first insulation measurement component 1101 may be composed of at least one resistor connected in series and / or in parallel.

[0047] In another preferred embodiment, the negative electrode impedance detection unit 111 includes a second insulation detection switch K2 and a second insulation measurement component 1111, wherein the first connection terminal of the second insulation detection switch K2 is connected to the battery negative electrode access port BAT-, the second connection terminal of the second insulation detection switch K2 is connected to the protective ground PE through the second insulation measurement component 1111, and the control terminal of the second insulation detection switch K2 is connected to the controller 12.

[0048] Specifically, the ER insulation measurement component 1111 may be composed of at least one resistor connected in series and / or in parallel.

[0049] The battery access control circuit provided in this application has the following working process:

[0050] When the battery pack is connected to the battery input port of the hybrid inverter, the controller controls the first insulation detection switch K1 to close and the second insulation detection switch K2 to open, and collects the positive terminal to ground voltage of the battery pack BAT.

[0051] The controller controls the first insulation detection switch K1 to open and the second insulation detection switch K2 to close, so as to collect the negative terminal voltage of the battery pack BAT to ground.

[0052] The controller calculates the positive terminal impedance to ground Rp and the negative terminal impedance to ground Rn of the battery pack.

[0053] The positive electrode impedance to ground Rp and the negative electrode impedance to ground Rn are compared with the specified value. If the positive electrode impedance to ground Rp is greater than or equal to the specified value and the negative electrode impedance to ground Rn is greater than or equal to the specified value, the ground impedance load requirement of the battery pack BAT is determined. The controller 12 controls the battery connection control switch 13 to close, and the battery pack BAT is connected to the hybrid inverter for operation.

[0054] If the positive electrode impedance to ground Rp is less than the specified value, or the negative electrode impedance to ground Rn is less than the specified value, then the battery pack BAT's impedance to ground is determined to be non-compliant. In this case, the controller 12 will control the battery connection control switch 13 to disconnect, and the battery pack BAT will be unable to connect to the hybrid inverter. An insulation impedance abnormality alarm will be triggered to prompt the user to troubleshoot the fault until the test results meet the requirements.

[0055] In this application, the specified value of the impedance to ground is determined according to the given standards of the region where the circuit is applied.

[0056] The advantages of this application are:

[0057] A battery access control circuit is added to the inverter battery port to detect the insulation resistance of the positive and negative terminals of the battery pack to ground, protecting the inverter from damage due to battery insulation failure.

[0058] Those skilled in the art will readily understand that, as described in the several embodiments provided in this application, the disclosed circuits can be implemented in other ways. The circuit embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the displayed or discussed mutual couplings or direct couplings or communication connections may be indirect couplings or communication connections through some communication interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0059] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0060] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0061] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A battery access control circuit, characterized in that, The battery access control circuit is located inside the hybrid inverter. The input terminal of the battery access control circuit is connected to the battery access port of the hybrid inverter, and the output terminal of the battery access control circuit is connected to the charging and discharging system.

2. The battery access control circuit according to claim 1, characterized in that, The battery access control circuit includes an insulation resistance detection module, and the battery access port includes a positive battery access port and a negative battery access port. The insulation impedance detection module is connected in parallel between the positive and negative battery input ports of the hybrid inverter.

3. The battery access control circuit according to claim 2, characterized in that, The battery access control circuit also includes a controller. The insulation detection control terminal of the insulation impedance detection module is connected to the controller.

4. The battery access control circuit according to claim 3, characterized in that, The battery access control circuit also includes a battery access control switch. The battery access control switch has a first connection terminal connected to the positive terminal of the battery, a second connection terminal connected to one end of the charging and discharging system, a other end of the charging and discharging system connected to the negative terminal of the battery, and a control terminal connected to the controller.

5. The battery access control circuit according to claim 3, characterized in that, The insulation resistance detection module includes a positive impedance detection unit. The first connection terminal of the positive impedance detection unit is connected to the positive terminal input port of the battery, the second connection terminal of the positive impedance detection unit is connected to the protective ground, and the control terminal of the positive impedance detection unit is connected to the controller.

6. The battery access control circuit according to claim 5, characterized in that, The positive impedance detection unit includes a first insulation detection switch and a first insulation measurement component. The first connection terminal of the first insulation detection switch is connected to the positive terminal of the battery, the second connection terminal of the first insulation detection switch is connected to the protective ground through the first insulation measurement component, and the control terminal of the first insulation detection switch is connected to the controller.

7. The battery access control circuit according to claim 3, characterized in that, The insulation resistance detection module includes a negative electrode resistance detection unit. The first connection terminal of the negative electrode impedance detection unit is connected to the negative electrode inlet port of the battery, the second connection terminal of the negative electrode impedance detection unit is connected to the protective ground, and the control terminal of the negative electrode impedance detection unit is connected to the controller.

8. The battery access control circuit according to claim 7, characterized in that, The negative electrode impedance detection unit includes a second insulation detection switch and a second insulation measurement component. The first connection terminal of the second insulation detection switch is connected to the negative terminal of the battery, the second connection terminal of the second insulation detection switch is connected to the protective ground through the second insulation measurement component, and the control terminal of the second insulation detection switch is connected to the controller.

9. The battery access control circuit according to claim 3, characterized in that, The controller is a digital signal processor.

10. The battery access control circuit according to claim 4, characterized in that, The battery access control circuit also includes a DC-DC converter. The first connection terminal of the DC-DC converter is connected to the second connection terminal of the battery access control switch, the second connection terminal of the DC-DC converter is connected to the negative terminal access port of the battery, the third connection terminal of the DC-DC converter is connected to one end of the charging and discharging system, and the fourth connection terminal of the DC-DC converter is connected to the other end of the charging and discharging system.

11. A hybrid inverter, characterized in that, The hybrid inverter has a built-in battery access control circuit as described in any one of claims 1-10, the battery access port of the hybrid inverter is connected to the battery pack, and the output terminal of the hybrid inverter is connected to the power supply load.

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