Isolation switch, isolation switch circuit and battery management system

Abstract

The utility model relates to an isolating switch, an isolating switch circuit and a battery management system. The isolating switch comprises an isolating capacitor and a switch main body; the switch main body comprises a power supply end, a control end, a first end and a second end; two ends of the isolation capacitor are respectively connected with the control end and the second end of the switch main body; the switch main body is used for connecting or disconnecting the connection between the first end and the second end according to a power supply signal input by the power supply end and a control signal input by the control end; and the isolation capacitor is used for shunting the current input into the switch main body. According to the invention, the probability that the isolating switch is mistakenly conducted due to signal interference can be reduced, so that the performance of the anti-interference system can meet the anti-interference requirement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery pack, in particular to an isolation switch and a battery management system. BACKGROUND

[0002] In order to improve the safety and reliability of electronic equipment, an anti-interference system is often arranged in the electronic equipment. Among them, the large current injection interference test can test the performance of the anti-interference system.

[0003] At present, a filter circuit is often arranged outside the anti-interference system to solve the problem that the system is interfered and the central processing unit is dead and cannot work when a large current is injected.

[0004] However, the above-mentioned method still has the problem that the isolation switch is misdirected on by signal interference, resulting in that the performance of the anti-interference system cannot meet the anti-interference requirement. CONTENT OF THE INVENTION

[0005] Based on the above problems, the present application provides an isolation switch, an isolation switch circuit and a battery management system, which can reduce the probability that the isolation switch is misdirected on by signal interference, so that the performance of the anti-interference system can meet the anti-interference requirement.

[0006] In a first aspect, the present application provides an isolation switch, which comprises an isolation capacitor and a switch main body; the switch main body comprises a power supply end, a control end, a first end and a second end; the two ends of the isolation capacitor are connected with the control end and the second end of the switch main body respectively; the switch main body is used for conducting or cutting off the connection between the first end and the second end according to the power supply signal input by the power supply end and the control signal input by the control end; and the isolation capacitor is used for shunting the current input to the switch main body.

[0007] In the technical scheme of the present application, the isolation capacitor can shunt the current input to the switch main body, thereby reducing the current input to the switch main body, so that the switch main body can still maintain the off state under the controlled off condition, thus greatly improving the anti-interference ability of the isolation switch, so that the performance of the anti-interference system can meet the anti-interference requirement.

[0008] In some embodiments, the switch main body comprises a switch capacitor and a primary side circuit and a secondary side circuit arranged on both sides of the switch capacitor; the primary side circuit is connected with the power supply end and the control end of the switch main body respectively; the secondary side circuit is connected with the first end and the second end of the switch main body respectively; the primary side circuit is used for driving the secondary side circuit to work according to the power supply signal of the power supply end and the control signal input by the control end; and the switch capacitor is used for isolating the interference signal input to the primary side circuit. In the technical scheme of the present application, the switch capacitor can filter the signal transmitted to the secondary side circuit, so that the primary side circuit can more accurately drive the secondary side circuit, thereby reducing the probability of misdirecting on of the switch main body.

[0009] In some embodiments, the secondary side circuit comprises a charge pump, a first switch tube and a second switch tube; an output terminal of the charge pump is connected with a control electrode of the first switch tube and a control electrode of the second switch tube; a first electrode of the first switch tube is connected with the first end of the switch body; a second electrode of the first switch tube is connected with a second electrode of the second switch tube; a first electrode of the second switch tube is connected with the second end of the switch body; the charge pump is configured to control the first switch tube and the second switch tube to be turned on or turned off under the driving of the primary side circuit. In the technical solution of the embodiments of the present application, in combination with the switch capacitor arranged in the isolation switch, the charge pump can receive the energy of the switch capacitor and amplify the energy, so as to accurately control the first switch tube and the second switch tube to be turned on or turned off, and thus make the isolation switch realize the function of being turned on or turned off.

[0010] In some embodiments, the primary side circuit comprises a power supply circuit, an oscillation circuit and a driving circuit connected in sequence; the power supply circuit is connected with the power supply terminal, and the driving circuit is connected with the control terminal; the power supply circuit is configured to drive the oscillation circuit to generate an oscillation signal according to the power supply signal of the power supply terminal; and the driving circuit is configured to drive the secondary side circuit to work according to the oscillation signal. In the technical solution of the embodiments of the present application, the primary side circuit is equivalent to a diode, and the function of driving the secondary side circuit can be realized, the circuit structure is simple and easy to realize, and the cost is relatively low.

[0011] In a second aspect, the present application further provides an isolation switch circuit, which comprises a first resistor, a second resistor and the isolation switch as described in the first aspect; a first end of the first resistor is connected with the first end of the switch body of the isolation switch, and a second end of the first resistor is coupled to a positive voltage port; a first end of the second resistor is connected with the second end of the switch body, and a second end of the second resistor is coupled to a negative voltage port; the first resistor and the second resistor form a voltage dividing circuit between the positive voltage port and the negative voltage port in the case that the isolation switch is controlled to be turned on. In the technical solution of the embodiments of the present application, the isolation capacitor in the isolation switch can shunt the current input into the switch body, so as to reduce the current input into the switch body, and the switch body can still maintain the off state in the case that it is controlled to be turned off, and thus the anti-interference capability of the isolation switch can be improved. Moreover, the first resistor and the second resistor form a voltage dividing circuit in the case that the isolation switch is controlled to be turned on, and the voltage dividing circuit can be used for voltage acquisition in various scenes, and since the anti-interference capability of the isolation switch is relatively strong, the voltage acquired by the isolation switch circuit is relatively accurate.

[0012] In some embodiments, the isolating switch circuit further comprises a control circuit, a first end of the control circuit is connected with the control end of the switch main body, a second end of the control circuit is connected with the low-voltage ground, and a third end of the control circuit is used for connecting an external micro control unit; the control circuit is used for controlling the switch main body to be turned on or turned off according to a signal input by the micro control unit. In the technical scheme of the embodiments of the application, the control circuit can convert the signal output by the micro control unit, so that the converted control signal is suitable for controlling the isolating switch, so that the restriction on the signal output by the micro control unit can be relaxed, and the isolating switch can be accurately controlled.

[0013] In some embodiments, the control circuit comprises a third switch tube; a control electrode of the third switch tube is used for being connected with the micro control unit, a first electrode of the third switch tube is connected with the control end of the switch main body, and a second electrode of the third switch tube is connected with the low-voltage ground. In the technical scheme of the embodiments of the application, the third switch tube can convert the signal output by the micro control unit, so that the converted control signal is suitable for controlling the isolating switch, so that the restriction on the signal output by the micro control unit can be relaxed, and the isolating switch can be accurately controlled.

[0014] In some embodiments, the isolating switch circuit further comprises a third resistance, a first end of the third resistance is used for being connected with the micro control unit, and a second end of the third resistance is connected with the control electrode of the third switch tube. In the technical scheme of the embodiments of the application, the third resistance can play a role of current limiting, so as to avoid that the current input to the third switch tube is too large, thereby damaging the third switch tube.

[0015] In some embodiments, the isolating switch circuit further comprises a fourth resistance; a first end of the fourth resistance is connected with the power supply end of the switch main body, and a second end of the fourth resistance is used for being connected with the power voltage port. In the technical scheme of the embodiments of the application, the fourth resistance can play a role of current limiting, so as to avoid that the current input to the switch main body is too large, thereby damaging the switch main body.

[0016] In a third aspect, the application further provides a battery management system, comprising a micro control unit, an insulation detection circuit and a voltage detection circuit, the insulation detection circuit and the voltage detection circuit being connected with a battery pack respectively, wherein the insulation detection circuit and the voltage detection circuit each comprise the isolation switch circuit as described in the second aspect; the micro control unit is connected with each isolation switch circuit respectively; the micro control unit is configured to control the on-off of each isolation switch circuit, so that the insulation detection circuit performs insulation detection on the battery pack, and the voltage detection circuit performs voltage detection on the battery pack. In the technical solution of the application, the insulation detection circuit and the voltage detection circuit of the battery management system each comprise the isolation switch circuit, the isolation switch circuit comprises an isolation capacitor and a switch main body, the isolation capacitor can shunt the current input to the switch main body, reduce the current input to the switch main body, and enable the switch main body to maintain the off state under the controlled off condition, so that the anti-interference capability of the isolation switch can be improved, the anti-interference capability of the isolation switch circuit is further improved, and the anti-interference performance of the battery management system meets the anti-interference requirement.

[0017] In some embodiments, the insulation detection circuit comprises a first isolation switch circuit and a second isolation switch circuit; a first end of the first isolation switch circuit is connected with the micro control unit, a second end of the first isolation switch circuit is connected with a positive electrode of the battery pack, and a third end of the first isolation switch circuit is connected with a second end of the second isolation switch circuit; a first end of the second isolation switch circuit is connected with the micro control unit, and a third end of the second isolation switch circuit is connected with a negative electrode of the battery pack; the micro control unit is configured to control the on-off of the first isolation switch circuit and the second isolation switch circuit, so that the insulation detection circuit performs insulation detection on the battery pack, wherein the conduction time of the first isolation switch circuit and the second isolation switch circuit is opposite. In the technical solution of the application, the micro control unit can collect the voltage division of the voltage division circuit by controlling the on-off of the isolation switch in the first isolation switch circuit and the on-off of the isolation switch in the second isolation switch circuit, so as to calculate the resistance value of the insulation resistance according to the voltage division, and further obtain the insulation detection result. Since the isolation switch of the first isolation switch circuit and the second isolation switch circuit is provided with the isolation capacitor, the anti-interference performance of the isolation switch is strong, so the anti-interference performance of the insulation detection circuit is strong, the insulation detection result is accurate, and the safety of the battery pack and personnel is protected.

[0018] In some embodiments, the voltage detection circuit comprises a third isolation switch circuit; a first end of the third isolation switch circuit is connected with the micro control unit, a second end of the third isolation switch circuit is connected with the positive pole of the battery pack, and a third end of the third isolation switch circuit is connected with the negative pole of the battery pack; the micro control unit is configured to control the on-off of the third isolation switch circuit, so that the voltage detection circuit detects the voltage of the battery pack. In the technical solution of the embodiments of the application, the micro control unit can collect the voltage division of the voltage division circuit by controlling the on-off of the isolation switch in the third isolation switch circuit, so as to obtain the voltage detection result according to the voltage division. Since the isolation switches of the third isolation switch circuit are all provided with isolation capacitors, the anti-interference performance of the isolation switches is strong, and therefore the anti-interference performance of the voltage detection circuit is strong, and the voltage detection result is relatively accurate, which can protect the safety of the battery pack and the electrical equipment. BRIEF DESCRIPTION OF DRAWINGS

[0019] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the alternative embodiments. The drawings are for purposes of illustration only and are not considered a limitation of the present application. Furthermore, like reference numerals are used to designate corresponding parts throughout the several views. In the drawings:

[0020] Figure 1 is one of the structure schematic diagrams of the isolation switch of an embodiment of the application;

[0021] Figure 2 is another of the structure schematic diagrams of the isolation switch of an embodiment of the application;

[0022] Figure 3 is a third of the structure schematic diagrams of the isolation switch of an embodiment of the application;

[0023] Figure 4a is an equivalent circuit schematic diagram of the isolation switch without isolation capacitors of an embodiment of the application;

[0024] Figure 4b is an equivalent circuit schematic diagram of the isolation switch with isolation capacitors of an embodiment of the application;

[0025] Figure 5 is a fourth of the structure schematic diagrams of the isolation switch of an embodiment of the application;

[0026] Figure 6 is one of the structure schematic diagrams of the isolation switch circuit of an embodiment of the application;

[0027] Figure 7 is another of the structure schematic diagrams of the isolation switch circuit of an embodiment of the application;

[0028] Figure 8Fig. 3 is a structural schematic diagram of an isolation switch circuit according to an embodiment of the present application;

[0029] Figure 9 Fig. 4 is a structural schematic diagram of an isolation switch circuit according to an embodiment of the present application;

[0030] Figure 10 Fig. 5 is a structural schematic diagram of an isolation switch circuit according to an embodiment of the present application;

[0031] Figure 11 Fig. 6 is a structural schematic diagram of a battery management system according to an embodiment of the present application;

[0032] Figure 12 Fig. 7 is a structural schematic diagram of a battery management system according to an embodiment of the present application;

[0033] Figure 13 Fig. 8 is a structural schematic diagram of a battery management system according to an embodiment of the present application;

[0034] Figure 14 Fig. 9 is a structural schematic diagram of a battery management system according to an embodiment of the present application.

[0035] Legend of reference signs:

[0036] Isolation switch 10, isolation capacitor Cs, switch main body 11;

[0037] Switch capacitor C ISO Primary side circuit 111, secondary side circuit 112;

[0038] Charge pump CP, first switch tube M1, second switch tube M2, diode e;

[0039] First resistor R1, second resistor R2, control circuit 20, third switch tube M3;

[0040] Third resistor R3, fourth resistor R4;

[0041] Micro control unit MCU, insulation detection circuit 01, voltage detection circuit 02;

[0042] First isolation switch circuit 011, second isolation switch circuit 012, third isolation switch circuit 021. DETAILED DESCRIPTION

[0043] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the use of the terms "including," "comprising," or "having" and variations thereof herein is intended to be broad and encompass the terms "consisting of" and "consisting essentially of" and variations thereof. Unless otherwise required by context, singular terms shall include pluralities and vice versa. Unless otherwise required by context, the use herein of the singular is also to be construed as a use of the plural and vice versa.

[0045] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise explicitly and specifically limited.

[0046] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification is not necessarily all referring to the same embodiment, or to a particular embodiment, or to a particular set of embodiments. It will be explicitly understood by those of ordinary skill in the art that the embodiments described herein can be combined with other embodiments.

[0047] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0048] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), and similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0049] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanical connection, or it can be electrical connection; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0050] In order to improve the security and reliability of electronic equipment, an anti-interference system is often arranged in the electronic equipment. Among them, the large current injection interference test can test the performance of the anti-interference system. At present, a filter circuit is often arranged outside the anti-interference system. In the case of large current injection, the filter circuit filters the current, so that the current input to the anti-interference system is reduced, thereby solving the problem that the system is interfered and the central processing unit is dead and cannot work. However, the above-mentioned method still has the problem that the isolation switch is misdirected on by signal interference, resulting in that the performance of the anti-interference system cannot meet the anti-interference requirement.

[0051] In view of the above problems, the embodiment of the present application provides an isolation switch, which comprises an isolation capacitor and a switch main body; the switch main body is controlled to be turned on or turned off, and the isolation capacitor is connected in parallel with the switch main body; the isolation capacitor can shunt the current input to the switch main body, so that the current input to the switch main body is reduced, and the switch main body can still maintain the off state under the controlled off condition, thereby greatly improving the anti-interference capability of the isolation switch, and further making the performance of the anti-interference system meet the anti-interference requirement.

[0052] The technical solutions provided by the embodiments of the present application will be described in detail below.

[0053] According to some embodiments of the present application, referring to Figure 1 , an isolation switch 10 is provided, which comprises an isolation capacitor Cs and a switch main body 11; the switch main body 11 comprises a power supply end Vin, a control end EN, a first end Out1 and a second end Out2; the two ends of the isolation capacitor Cs are connected with the control end EN and the second end Out2 of the switch main body 11 respectively; the switch main body 11 is used for turning on or cutting off the connection between the first end Out1 and the second end Out2 according to the power supply signal input by the power supply end Vin and the control signal input by the control end EN; and the isolation capacitor Cs is used for shunting the current input to the switch main body 11.

[0054] In the embodiment of the present application, the isolation switch 10 comprises the switch main body 11, the switch main body 11 comprises the power supply end Vin, the control end EN, the first end Out1 and the second end Out2, the power supply end Vin can be connected with a power supply voltage port Vs to obtain a power supply signal for the working of the isolation switch 10, and the control end EN can be connected with an external controller, processor or the like to receive a control signal. In the case that the control signal controls the switch main body 11 to be turned on, the switch main body 11 turns on the connection between the first end Out1 and the second end Out2; and in the case that the control signal controls the switch main body 11 to be turned off, the switch main body 11 cuts off the connection between the first end Out1 and the second end Out2.

[0055] The isolating switch 10 further comprises an isolation capacitor Cs, two ends of the isolation capacitor Cs being connected with the control end EN and the second end Out2 of the switch main body 11 respectively. In the case that the external device inputs a large current to the isolating switch 10, the isolation capacitor Cs will shunt the current, so that the current flowing into the switch main body 11 is reduced, and the voltage applied to the switching device in the switch main body 11 is also reduced, and the switching device in the switch main body 11 will not be turned on under the reduced voltage, and thus the switch main body 11 can still maintain the off state under the controlled off.

[0056] In the above embodiment, the isolating switch comprises an isolation capacitor and a switch main body; the switch main body is controlled to be turned on or off, and the isolation capacitor is connected in parallel with the switch main body. In the technical solution of the embodiment of the present application, the isolation capacitor can shunt the current input to the switch main body, so as to reduce the current input to the switch main body, and the switch main body can still maintain the off state under the controlled off, and thus the anti-interference capability of the isolating switch is greatly improved, and the performance of the anti-interference system can meet the anti-interference requirement.

[0057] According to some embodiments of the present application, referring to Figure 2 , the switch main body 11 comprises a switching capacitor C ISO and a primary side circuit 111 and a secondary side circuit 112 arranged on two sides of the switching capacitor C ISO ; the primary side circuit 111 is connected with the power supply end Vin and the control end EN of the switch main body 11 respectively; the secondary side circuit 112 is connected with the first end Out1 and the second end Out2 of the switch main body 11 respectively; the primary side circuit 111 is used for driving the secondary side circuit 112 to work according to the power supply signal of the power supply end Vin and the control signal input by the control end EN; and the switching capacitor C ISO is used for isolating the interference signal input by the primary side circuit 111.

[0058] In the embodiment of the present application, the switch main body 11 comprises a switching capacitor C ISO , a primary side circuit 111 and a secondary side circuit 112. The primary side circuit 111 is connected with the power supply end Vin and the control end EN of the switch main body 11 respectively; and the secondary side circuit 112 is connected with the first end Out1 and the second end Out2 of the switch main body 11 respectively.

[0059] The power supply end Vin of the switch main body 11 receives a power supply signal to supply power for the primary side circuit 111; the control end EN receives a control signal, under the condition that the control signal controls the switch main body 11 to be turned on, the primary side circuit 111 drives the secondary side circuit 112 to work, and the secondary side circuit 112 turns on the connection between the first end Out1 and the second end Out2 of the switch main body 11; under the condition that the control signal controls the switch main body 11 to be turned off, the primary side circuit 111 does not work, and then does not drive the secondary side circuit 112, the secondary side circuit 112 does not work, and then cuts off the connection between the first end Out1 and the second end Out2 of the switch main body 11.

[0060] The switch capacitor C ISO is arranged between the primary side circuit 111 and the secondary side circuit 112, when the primary side circuit 111 drives the secondary side circuit 112 to work, the switch capacitor C ISO isolates the interference signal input by the primary side circuit 111.

[0061] It should be noted that, at high frequency, the switch capacitor C ISO is equivalent to a short circuit, which can bypass the high-frequency interference signal to the ground, thereby achieving the effect of filtering out high-frequency interference.

[0062] In the above embodiment, the switch main body includes a switch capacitor and a primary side circuit and a secondary side circuit arranged on both sides of the switch capacitor, the primary side circuit drives the secondary side circuit to work according to the power supply signal of the power supply end and the control signal input by the control end; the switch capacitor isolates the interference signal input by the primary side circuit. In the technical scheme of the embodiment of the application, the switch capacitor can filter the signal transmitted to the secondary side circuit, so that the primary side circuit can more accurately drive the secondary side circuit, thereby reducing the probability of mis-conduction of the switch main body.

[0063] According to some embodiments of the application, referring to Figure 3 , the secondary side circuit 112 includes a charge pump CP, a first switch tube M1 and a second switch tube M2; the output end of the charge pump CP is connected with the control electrode of the first switch tube M1 and the control electrode of the second switch tube M2; the first electrode of the first switch tube M1 is connected with the first end Out1 of the switch main body 11; the second electrode of the first switch tube M1 is connected with the second electrode of the second switch tube M2; the first electrode of the second switch tube M2 is connected with the second end Out2 of the switch main body 11; the charge pump CP is used to control the first switch tube M1 and the second switch tube M2 to be turned on or turned off under the driving of the primary side circuit 111.

[0064] In the embodiment of the present application, the secondary side circuit 112 includes a charge pump CP, a first switch tube M1 and a second switch tube M2. The output terminal of the charge pump CP is connected with the control electrode of the first switch tube M1 and the control electrode of the second switch tube M2, the first electrode of the first switch tube M1 is connected with the first end Out1 of the switch body 11; the second electrode of the first switch tube M1 is connected with the second electrode of the second switch tube M2; and the first electrode of the second switch tube M2 is connected with the second end Out2 of the switch body 11.

[0065] In the case of controlling the switch body 11 to be turned on, the charge pump CP works under the driving of the primary side circuit 111, the first switch tube M1 and the second switch tube M2 are both controlled to be turned on, and the first end Out1 of the switch body 11 is communicated with the second end Out2 of the switch body 11 through the first switch tube M1 and the second switch tube M2. In the case of controlling the switch body 11 to be turned off, the charge pump CP does not work, the first switch tube M1 and the second switch tube M2 are both turned off, and the connection between the first end Out1 of the switch body 11 and the second end Out2 of the switch body 11 is cut off.

[0066] In some embodiments, the first switch tube M1 and the second switch tube M2 are both N-type transistors, in the case that the charge pump CP outputs high level under the driving of the primary side circuit 111, the first switch tube M1 and the second switch tube M2 are both turned on, and the first end Out1 of the switch body 11 is communicated with the second end Out2 of the switch body 11 through the first switch tube M1 and the second switch tube M2. In the case that the charge pump CP does not work, the first switch tube M1 and the second switch tube M2 are both turned off, and the connection between the first end Out1 of the switch body 11 and the second end Out2 of the switch body 11 is cut off.

[0067] In the case that the external device inputs large current to the isolation switch 10, it may cause the voltage output by the charge pump CP to be higher than the turn-on threshold voltage of the first switch tube M1 and the second switch tube M2, so that the first switch tube M1 and the second switch tube M2 are mis-conducted. The isolation capacitor Cs in the embodiment of the present application can shunt the current input to the isolation switch 10, so that the current input to the switch body 11 is reduced, and then the voltage output by the charge pump CP will not be higher than the turn-on threshold voltage of the first switch tube M1 and the second switch tube M1, so that the first switch tube M1 and the second switch tube M2 are mis-conducted. Therefore, the isolation switch 10 can still maintain the off state in the case of being controlled to be turned off.

[0068] When the isolation capacitor Cs is set, the capacitance value of the isolation capacitor Cs can be isolated in the following manner:

[0069] First, set the current input to the isolation switch 10 as , the first end Out1 and the second end Out2 of the switch body 11 are connected with the load resistor R LDue to the unidirectional conductivity of the diode inside the charge pump CP, the load resistance R... L The current should be a half-sine wave. Since there is current output for half a cycle and no current output for the other half of a sinusoidal cycle, the load resistance R... L The average value of the current after rectification is shown in formula (1):

[0070] ---------------(1)

[0071] Where T is the period of the sine wave.

[0072] Applied to the load resistor R L The voltage on it is as shown in formula (2):

[0073] --------------(2)

[0074] Where I1 is the average value of the rectified current, and Vo is the current applied to the load resistor R. L The voltage on it.

[0075] If the output voltage of the charge pump CP exceeds the turn-on threshold voltage of the first switch M1 and the second switch M2 due to current input, the isolating switch 10 will falsely turn on. Experimental testing revealed that because the discharge degree of the input current varies at different frequencies ω, the amplitude of the actual input current increases with increasing input frequency, making false turn-on more likely. Therefore, this can be addressed by adjusting the current at different frequencies... Take measurements.

[0076] Equivalent treatment is applied to the disconnecting switch 10 that does not have an isolation capacitor Cs, such as... Figure 4a As shown, C ISO C1 is the equivalent capacitance of the charge pump CP, and D1 and D2 are the equivalent capacitances of the first switching transistor M1 and the second switching transistor M2. The load resistor R... L After performing fundamental wave equivalence processing, we can obtain formula (3):

[0077] -------------------------------------------(3)

[0078] Among them, R L ' is the equivalent resistance.

[0079] The isolating switch 10 with isolation capacitor Cs is treated equivalently, such as... Figure 4b As shown, the input current can be expressed as formula (4):

[0080] (4)

[0081] After setting the isolation capacitor Cs, the voltage applied on the load resistor R L is formula (5):

[0082] ----(5)

[0083] By combining the current size under different frequencies ω and the above formula, let The capacitance value of the isolation capacitor Cs can be solved.

[0084] In the above embodiment, the secondary side circuit includes a charge pump, a first switch tube and a second switch tube; the charge pump controls the first switch tube and the second switch tube to be turned on or turned off under the driving of the primary side circuit. In the technical solution of the embodiment of the application, in combination with the switch capacitor arranged in the isolation switch, the charge pump can receive the energy of the switch capacitor and amplify the energy, so as to accurately control the first switch tube and the second switch tube to be turned on or turned off, and thus make the isolation switch realize the functions of being turned on or turned off.

[0085] According to some embodiments of the application, the primary side circuit 111 includes a power supply circuit, an oscillation circuit and a driving circuit connected in sequence; the power supply circuit is connected with the power supply end Vin, and the driving circuit is connected with the control end EN; the power supply circuit is used to drive the oscillation circuit to generate an oscillation signal according to the power supply signal of the power supply end; and the driving circuit is used to drive the secondary side circuit 112 to work according to the oscillation signal.

[0086] In the embodiment of the application, the primary side circuit 111 includes a power supply circuit, an oscillation circuit and a driving circuit connected in sequence, and the power supply circuit, the oscillation circuit and the driving circuit are equivalent to a diode e, refer to Figure 5 , the anode of the diode e is connected with the power supply end Vin, and the cathode of the diode e is connected with the control end EN. In the case that the voltage difference between the power supply end Vin and the control end EN is greater than the threshold voltage of the diode e, the diode e is turned on, and the charge pump CP of the secondary side circuit 112 works.

[0087] In the technical solution of the embodiment of the application, the primary side circuit is equivalent to a diode, and the function of driving the secondary side circuit can be realized, the circuit structure is simple and easy to realize, and the cost is relatively low.

[0088] According to some embodiments of the application, refer to Figure 6The isolation switch circuit comprises a first resistor R1, a second resistor R2 and the isolation switch 10 in the above embodiment; a first end of the first resistor R1 is connected with a first end Out1 of a switch main body 11 of the isolation switch 10, and a second end of the first resistor R1 is coupled to a positive voltage port U+; a first end of the second resistor R2 is connected with a second end Out2 of the switch main body 11, and a second end of the second resistor R2 is coupled to a negative voltage port U-; the first resistor R1 and the second resistor R2 form a voltage dividing circuit between the positive voltage port U+ and the negative voltage port U- when the isolation switch 10 is controlled to be turned on.

[0089] In the embodiment, the isolation switch circuit comprises a first resistor R1, a second resistor R2 and the isolation switch 10 in the above embodiment, a first end of the first resistor R1 is connected with a first end Out1 of a switch main body 11, and a second end of the first resistor R1 is connected with a positive voltage port U+; a first end of the second resistor R2 is connected with a second end Out2 of the switch main body 11, and a second end of the second resistor R2 is connected with a negative voltage port U-.

[0090] The power supply end Vin of the switch main body 11 of the isolation switch 10 obtains a power supply signal, and the control end EN of the switch main body 11 receives a control signal. When the switch main body 11 is controlled to be turned on by the control signal, the voltage difference between the power supply end Vin and the control end EN of the switch main body 11 is greater than the turn-on threshold voltage of the diode e, the diode e is turned on, and the charge pump CP is driven to work. The charge pump CP controls the first switch tube M1 and the second switch tube M2 to be turned on, and the first end of the first resistor R1 is connected with the first end of the second resistor R2 through the first switch tube M1 and the second switch tube M2, that is, the first resistor R1 and the second resistor R2 are connected in series. Since the second end of the first resistor R1 is connected with the positive voltage port U+, and the second end of the second resistor R2 is connected with the negative voltage port U-, the first resistor R1 and the second resistor R2 form a voltage dividing circuit between the positive voltage port U+ and the negative voltage port U-.

[0091] The isolation switch 10 comprises an isolation capacitor Cs, and the two ends of the isolation capacitor Cs are connected with the control end EN and the second end Out2 of the switch main body 11, respectively. In the case that the external device inputs a large current to the isolation switch 10, the isolation capacitor Cs will shunt the current, so that the current flowing into the switch main body 11 will be reduced, and the voltage transmitted to the first switch tube M1 and the second switch tube M2 in the switch main body 11 will also be reduced, thereby the probability of the first switch tube M1 and the second switch tube M2 being mistakenly turned on can be reduced, and the isolation switch 10 can still maintain the off state when being controlled to be turned off.

[0092] In the above embodiment, the isolating switch circuit includes the first resistor, the second resistor and the isolating switch; the first resistor and the second resistor form a voltage dividing circuit between the positive voltage port and the negative voltage port when the isolating switch is controlled to be turned on. In the technical solution of the embodiment of the application, the isolation capacitor in the isolating switch can shunt the current input to the switch body, thereby reducing the current input to the switch body, so that the switch body can still maintain the off state when being controlled to be turned off, and therefore the anti-interference capability of the isolating switch can be improved. Moreover, the first resistor and the second resistor form a voltage dividing circuit when the isolating switch is controlled to be turned on, and the voltage dividing circuit can be used for voltage collection in various scenarios, and because the anti-interference capability of the isolating switch is relatively strong, the voltage collected by the isolating switch circuit is relatively accurate.

[0093] According to some embodiments of the application, with reference to Figure 7 , the isolating switch circuit further includes a control circuit 20, a first end of the control circuit 20 is connected with the control end EN of the switch body 11, a second end of the control circuit 20 is connected with the low-voltage ground GND, and a third end of the control circuit 20 is used for connecting an external microcontroller unit MCU; the control circuit 20 is used for controlling the switch body 11 to be turned on or turned off according to a signal input by the microcontroller unit MCU.

[0094] In the embodiment of the application, the isolating switch circuit further includes a control circuit 20, the control circuit 20 is connected with the control end EN of the switch body 11, the low-voltage ground GND and the external microcontroller unit MCU respectively. A first end of the isolation capacitor Cs can be connected with the control end EN of the switch body 11 through the control circuit 20, and a second end of the isolation capacitor Cs is connected with the negative voltage port U-.

[0095] The microcontroller unit MCU inputs a signal to the control circuit 20, the signal controls the control circuit 20 to turn on the connection between the control end EN of the switch body 11 and the low-voltage ground GND, or cut off the connection between the control end EN of the switch body 11 and the low-voltage ground GND.

[0096] In the case that the control circuit 20 turns on the connection between the control end EN of the switch body 11 and the low-voltage ground GND, the voltage difference between the power supply end Vin and the control end EN of the switch body 11 is a power supply signal, the power supply signal is greater than the turn-on threshold voltage of the diode e, the diode e is turned on and drives the charge pump CP to work. The charge pump CP controls the first switch tube M1 and the second switch tube M2 to be turned on. After the first switch tube M1 and the second switch tube M2 are turned on, the first resistor R1 and the second resistor R2 are connected in series between the positive voltage port U+ and the negative voltage port U- to form a voltage dividing circuit.

[0097] In the case that the control circuit 20 cuts off the connection between the control end EN of the switch main body 11 and the low-voltage ground GND, the voltage difference between the power supply end Vin and the control end EN of the switch main body 11 is lower than the conduction threshold voltage of the diode e, the diode e does not work, the charge pump CP does not work, the first switch tube M1 and the second switch tube M2 are turned off, and the connection between the first resistor R1 and the second resistor R2 is cut off.

[0098] In the above embodiment, the isolating switch circuit further comprises a control circuit, and the control circuit controls the switch main body to be turned on or turned off according to a signal input by the micro control unit. In the technical solution of the embodiment of the application, the control circuit can convert the signal output by the micro control unit, so that the converted control signal is suitable for controlling the isolating switch. In this way, the restriction on the signal output by the micro control unit can be relaxed, and the isolating switch can be accurately controlled.

[0099] According to some embodiments of the application, with reference to Figure 8 The control circuit 20 comprises a third switch tube M3, the control electrode of the third switch tube M3 is connected with the micro control unit MCU, the first electrode of the third switch tube M3 is connected with the control end EN of the switch main body 11, and the second electrode of the third switch tube M3 is connected with the low-voltage ground GND.

[0100] In the embodiment of the application, the control circuit 20 comprises a third switch tube M3, the control electrode of the third switch tube M3 is connected with the micro control unit MCU, the first electrode of the third switch tube M3 is connected with the control end EN of the switch main body 11, and the second electrode of the third switch tube M3 is connected with the low-voltage ground GND.

[0101] The micro control unit MCU inputs a signal to the control electrode of the third switch tube M3, so as to turn on or turn off the third switch tube M3, thereby turning on or cutting off the connection between the control end EN of the switch main body 11 and the low-voltage ground GND.

[0102] In the case that the third switch tube M3 is turned on, the control end EN of the switch main body 11 is connected with the low-voltage ground GND, the voltage difference between the power supply end Vin and the control end EN of the switch main body 11 is a power supply signal, the power supply signal is greater than the conduction threshold voltage of the diode e, the diode e is turned on and drives the charge pump CP to work. The charge pump CP controls the first switch tube M1 and the second switch tube M2 to be turned on. After the first switch tube M1 and the second switch tube M2 are turned on, the first resistor R1 and the second resistor R2 are connected in series between the positive voltage port U+ and the negative voltage port U- to form a voltage dividing circuit.

[0103] In the case that the third switch tube M3 is off, the connection between the control end EN of the switch body 11 and the low-voltage ground GND is cut off, the voltage difference between the power supply end Vin and the control end EN of the switch body 11 is lower than the conduction threshold voltage of the diode e, the diode e does not work, the charge pump CP does not work, the first switch tube M1 and the second switch tube M2 are off, and the connection between the first resistor R1 and the second resistor R2 is cut off.

[0104] In some embodiments, in the case that the third switch tube M3 is an N-type transistor, the micro control unit MCU inputs a high level to the control electrode of the third switch tube M3, the third switch tube M3 is turned on, thereby turning on the connection between the control end EN of the switch body 11 and the low-voltage ground GND. The micro control unit MCU inputs a low level to the control electrode of the third switch tube M3, the third switch tube M3 is turned off, thereby cutting off the connection between the control end EN of the switch body 11 and the low-voltage ground GND.

[0105] In some embodiments, in the case that the third switch tube M3 is a P-type transistor, the micro control unit MCU inputs a low level to the control electrode of the third switch tube M3, the third switch tube M3 is turned on, thereby turning on the connection between the control end EN of the switch body 11 and the low-voltage ground GND. The micro control unit MCU inputs a high level to the control electrode of the third switch tube M3, the third switch tube M3 is turned off, thereby cutting off the connection between the control end EN of the switch body 11 and the low-voltage ground GND.

[0106] In the technical scheme of the embodiments of the present application, the third switch tube can convert the signal output by the micro control unit, so that the converted control signal is suitable for controlling the disconnecting switch. In this way, the restriction on the signal output by the micro control unit can be relaxed, and the disconnecting switch can be accurately controlled.

[0107] According to some embodiments of the present application, referring to Figure 9 , the disconnecting switch circuit further comprises a third resistor R3, a first end of the third resistor R3 is used for being connected with the micro control unit MCU, and a second end of the third resistor R3 is connected with the control electrode of the third switch tube M3.

[0108] In the embodiments of the present application, the disconnecting switch circuit further comprises a third resistor R3, which is arranged between the micro control unit MCU and the control electrode of the third switch tube M3. In the technical scheme of the embodiments of the present application, the third resistor can play a role of current limiting, so as to avoid that the current input to the third switch tube is too large, thereby damaging the third switch tube.

[0109] According to some embodiments of the present application, referring to Figure 10 , the disconnecting switch circuit further comprises a fourth resistor R4; a first end of the fourth resistor R4 is connected with the power supply end Vin of the switch body 11, and a second end of the fourth resistor R4 is used for being connected with the power supply signal port Vs.

[0110] In the embodiment of the present application, the isolating switch circuit further includes a fourth resistor R4, which is arranged between the power supply end Vin of the switch main body 11 and the power supply signal port Vs. In the technical solution of the embodiment of the present application, the fourth resistor can play a current limiting role, so as to avoid too large current input into the switch main body and thus damage the switch main body.

[0111] According to some embodiments of the present application, referring to Figure 11 , a battery management system is provided. The battery management system 1 includes a micro control unit MCU, an insulation detection circuit 01 and a voltage detection circuit 02, the insulation detection circuit 01 and the voltage detection circuit 02 are connected with a battery pack 2 respectively, wherein the insulation detection circuit 01 and the voltage detection circuit 02 respectively include the isolating switch circuit in the above-mentioned embodiments; the micro control unit MCU is connected with each isolating switch circuit respectively; the micro control unit MCU is used for controlling the on-off of each isolating switch circuit, so as to make the insulation detection circuit 01 perform insulation detection on the battery pack 2 and the voltage detection circuit 02 perform voltage detection on the battery pack 2.

[0112] In the embodiment of the present application, the battery management system 1 includes a micro control unit MCU, an insulation detection circuit 01 and a voltage detection circuit 02. The insulation detection circuit 01 and the voltage detection circuit 02 both include the isolating switch circuit in the above-mentioned embodiments. The insulation detection circuit 01 is connected with the positive electrode and the negative electrode of the battery pack 2 respectively, and the voltage detection circuit 02 is connected with the positive electrode and the negative electrode of the battery pack 2 respectively.

[0113] The micro control unit MCU is connected with each isolating switch circuit and inputs a control signal to each isolating switch circuit. The isolating switch in the isolating switch circuit is turned on under the control of the control signal, so that the first resistor and the second resistor in the isolating switch circuit form a voltage dividing circuit.

[0114] The micro control unit MCU obtains a first voltage from the voltage dividing circuit formed by the insulation detection circuit 01 and performs insulation detection on the battery pack 2 according to the first voltage. Optionally, the resistance value of the insulation resistance between the positive electrode of the battery pack 2 and zero potential is calculated according to the first voltage. The resistance value of the insulation resistance should be greater than a preset resistance threshold value, because too small resistance value of the insulation resistance is easy to cause electric shock.

[0115] The micro control unit MCU obtains a second voltage from the voltage dividing circuit formed by the voltage detection circuit 02 and performs voltage detection on the battery pack 2 according to the second voltage. Optionally, whether the voltage of the battery pack 2 is greater than a preset voltage threshold value is determined according to the second voltage, because the voltage of the battery pack 2 greater than the preset voltage threshold value is easy to cause overvoltage of the electric equipment and thus cause failure of the electric equipment.

[0116] In the above embodiment, the battery management system includes a micro control unit, an insulation detection circuit and a voltage detection circuit. The micro control unit controls the on-off of each isolation switch circuit, so that the insulation detection circuit performs insulation detection on the battery pack, and the voltage detection circuit performs voltage detection on the battery pack. In the technical solution of the embodiment of the application, the insulation detection circuit and the voltage detection circuit of the battery management system both include an isolation switch circuit, and the isolation switch circuit includes an isolation capacitor and a switch main body. The isolation capacitor can shunt the current input to the switch main body, reduce the current input to the switch main body, and enable the switch main body to maintain the off state under the controlled off condition. Therefore, the anti-interference capability of the isolation switch can be improved, and the anti-interference capability of the isolation switch circuit is improved, so that the anti-interference performance of the battery management system meets the anti-interference requirement.

[0117] According to some embodiments of the application, with reference to Figure 12 The insulation detection circuit 01 includes a first isolation switch circuit 011 and a second isolation switch circuit 012. The first end of the first isolation switch circuit 011 is connected with the micro control unit MCU, the second end of the first isolation switch circuit 011 is connected with the positive electrode of the battery pack 2, and the third end of the first isolation switch circuit 011 is connected with the second end of the second isolation switch circuit 012. The first end of the second isolation switch circuit 012 is connected with the micro control unit MCU, and the third end of the second isolation switch circuit 012 is connected with the negative electrode of the battery pack 2. The micro control unit MCU is configured to control the on-off of the first isolation switch circuit 011 and the second isolation switch circuit 012, so that the insulation detection circuit 01 performs insulation detection on the battery pack 2. The conduction time of the first isolation switch circuit 011 and the second isolation switch circuit 012 is opposite.

[0118] In the embodiment of the application, the insulation detection circuit 01 includes a first isolation switch circuit 011 and a second isolation switch circuit 012. The first isolation switch circuit 011 is connected with the micro control unit MCU, the positive electrode of the battery pack 2 and the second isolation switch circuit 012 respectively. The second isolation switch circuit 012 is further connected with the micro control unit MCU and the negative electrode of the battery pack 2 respectively. There are insulation resistances Rp and Rn between the positive and negative electrodes of the battery pack 2. The first isolation switch circuit 011 is connected in parallel with the insulation resistance Rp, and the second isolation switch circuit 012 is connected in parallel with the insulation resistance Rn.

[0119] The micro control unit MCU outputs control signals to the first isolation switch circuit 011 and the second isolation switch circuit 012 respectively, controls the isolation switch in the first isolation switch circuit 011 to be turned on, and controls the isolation switch in the second isolation switch circuit 012 to be turned off, so that the first resistor R1 and the second resistor R2 in the first isolation switch circuit 011 are connected in series to form a voltage dividing circuit, the voltage dividing circuit and the insulation resistor Rp are connected in parallel to form a parallel circuit, and the parallel circuit and the insulation resistor Rn are connected in series. The micro control unit MCU obtains the voltage division of the second resistor R2 in the first isolation switch circuit 011.

[0120] The micro control unit MCU continues to output control signals to the first isolation switch circuit 011 and the second isolation switch circuit 012 respectively, controls the isolation switch in the first isolation switch circuit 011 to be turned off, and controls the isolation switch in the second isolation switch circuit 012 to be turned on, so that the first resistor R1 and the second resistor R2 in the second isolation switch circuit 012 are connected in series to form a voltage dividing circuit, the voltage dividing circuit and the insulation resistor Rn are connected in parallel to form a parallel circuit, and the parallel circuit and the insulation resistor Rp are connected in series. The micro control unit MCU obtains the voltage division of the second resistor R2 in the second isolation switch circuit 012.

[0121] The resistance values of the first resistor R1 and the second resistor R2 in the first isolation switch circuit 011 and the second isolation switch circuit 012 are known, and according to the obtained voltage division of the second resistor R2 in the first isolation switch circuit 011 and the voltage division of the second resistor R2 in the second isolation switch circuit 012, the resistance values of the insulation resistors Rp and Rn can be solved.

[0122] The micro control unit MCU obtains the insulation detection result according to the resistance values of the insulation resistors Rp and Rn, and the insulation detection result represents whether the insulation between the positive electrode of the battery pack 2 and the zero potential is normal.

[0123] In the above embodiment, the insulation detection circuit includes the first isolation switch circuit and the second isolation switch circuit. In the technical solution of the embodiment of the application, the micro control unit can collect the voltage division of the voltage dividing circuit by controlling the on-off of the isolation switch in the first isolation switch circuit and the on-off of the isolation switch in the second isolation switch circuit, so as to calculate the resistance value of the insulation resistor according to the voltage division, and then obtain the insulation detection result. Since the isolation switches of the first isolation switch circuit and the second isolation switch circuit are both provided with isolation capacitors, the anti-interference performance of the isolation switches is strong, so the anti-interference performance of the insulation detection circuit is strong, and the insulation detection result is relatively accurate, thereby protecting the safety of the battery pack and the personnel.

[0124] According to some embodiments of the application, with reference to Figure 13The voltage detection circuit 02 includes a third isolation switch circuit 021. A first end of the third isolation switch circuit 021 is connected with the micro control unit MCU, a second end of the third isolation switch circuit 021 is connected with the positive pole of the battery pack 2, and a third end of the third isolation switch circuit 021 is connected with the negative pole of the battery pack 2. The micro control unit MCU is configured to control the on-off of the third isolation switch circuit 021, so that the voltage detection circuit 02 detects the voltage of the battery pack 2.

[0125] In the embodiments of the present application, the voltage detection circuit 02 includes the third isolation switch circuit 021, and the third isolation switch circuit 021 is connected with the micro control unit MCU, the positive pole and the negative pole of the battery pack 2 respectively.

[0126] The micro control unit MCU inputs a control signal to the isolation switch in the third isolation switch circuit 021 to control the isolation switch to be conductive, and the first resistor R1 and the second resistor R2 in the third isolation switch circuit 021 are connected in series to form a voltage dividing circuit. The micro control unit obtains the voltage division of the second resistor R2 in the third isolation switch circuit 021, and the voltage detection result can be obtained according to the voltage division. The voltage detection result represents whether the voltage of the battery pack 2 is normal.

[0127] In some embodiments, the connection relationship between the battery management system and the battery pack 2 is shown in FIG. 1. Figure 14 .

[0128] In the above embodiments, the voltage detection circuit includes the third isolation switch circuit. In the technical solution of the embodiments of the present application, the micro control unit can collect the voltage division of the voltage dividing circuit by controlling the on-off of the isolation switch in the third isolation switch circuit, so as to obtain the voltage detection result according to the voltage division. Since the isolation switches in the third isolation switch circuit are all provided with isolation capacitors, the anti-interference performance of the isolation switches is strong, and therefore the anti-interference performance of the voltage detection circuit is strong, the voltage detection result is relatively accurate, and the safety of the battery pack and the electrical equipment can be protected.

[0129] The technical features of the above-described embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, it should be considered that they are within the scope of the present application.

[0130] The above-described embodiments only express several implementation manners of the present application, facilitate specific and detailed understanding of the technical solutions of the present application, but cannot be understood as a limitation on the protection scope of the utility model patent. It should be pointed out that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. It should be understood that, on the basis of the technical solutions provided by the present application, the technical solutions obtained by logical analysis, reasoning or limited experiments by the skilled person in the art all belong to the protection scope of the appended claims of the present application. Therefore, the protection scope of the patent of the present application should be subject to the content of the appended claims, and the description and drawings can be used to explain the content of the claims.

Claims

1. A disconnector, characterized in that The isolating switch comprises an isolation capacitor and a switch body; the switch body comprises a power supply end, a control end, a first end and a second end; two ends of the isolation capacitor are connected with the control end and the second end of the switch body respectively; The switch body is used for turning on or turning off the connection between the first end and the second end according to the power supply signal input by the power supply end and the control signal input by the control end; The isolation capacitor is used for shunting the current input to the switch body.

2. The disconnector according to claim 1, characterized in that The switch body comprises a switch capacitor and a primary side circuit and a secondary side circuit arranged on two sides of the switch capacitor; The primary side circuit is connected with the power supply end and the control end of the switch body respectively; The secondary side circuit is connected with the first end and the second end of the switch body respectively; The primary side circuit is used for driving the secondary side circuit to work according to the power supply signal of the power supply end and the control signal input by the control end; The switch capacitor is used for isolating the interference signal input by the primary side circuit.

3. The disconnector according to claim 2, characterized in that The secondary side circuit comprises a charge pump, a first switch tube and a second switch tube; The output end of the charge pump is connected with the control pole of the first switch tube and the control pole of the second switch tube; The first pole of the first switch tube is connected with the first end of the switch body; the second pole of the first switch tube is connected with the second pole of the second switch tube; The first pole of the second switch tube is connected with the second end of the switch body; The charge pump is used for controlling the first switch tube and the second switch tube to turn on or turn off under the driving of the primary side circuit.

4. The disconnector according to claim 2, characterized in that The primary side circuit comprises a power supply circuit, an oscillation circuit and a driving circuit connected in sequence; the power supply circuit is connected with the power supply end, and the driving circuit is connected with the control end; The power supply circuit is used for driving the oscillation circuit to generate an oscillation signal according to the power supply signal of the power supply end; The driving circuit is used for driving the secondary side circuit to work according to the oscillation signal.

5. A disconnector circuit, characterized by The isolating switch circuit comprises a first resistor, a second resistor and the isolating switch according to any one of claims 1-4; The first end of the first resistor is connected with the first end of the switch body of the isolating switch, and the second end of the first resistor is coupled to a positive voltage port; The first end of the second resistor is connected with the second end of the switch body, and the second end of the second resistor is coupled to a negative voltage port; The first resistor and the second resistor form a voltage dividing circuit between the positive voltage port and the negative voltage port when the isolating switch is controlled to turn on.

6. The isolating switch circuit of claim 5, wherein, The isolating switch circuit further comprises a control circuit; the first end of the control circuit is connected with the control end of the switch body, the second end of the control circuit is connected with a low-voltage ground, and the third end of the control circuit is used for connecting an external micro control unit; The control circuit is used for controlling the switch body to turn on or turn off according to the signal input by the micro control unit.

7. The isolating switch circuit of claim 6, wherein, The control circuit comprises a third switch tube; The control electrode of the third switch tube is used to be connected with the micro control unit, the first electrode of the third switch tube is connected with the control end of the switch body, and the second electrode of the third switch tube is connected with the low-voltage ground.

8. The isolating switch circuit of claim 7, wherein, The isolating switch circuit further comprises a third resistor, the first end of the third resistor is used to be connected with the micro control unit, and the second end of the third resistor is connected with the control electrode of the third switch tube.

9. The isolating switch circuit of claim 5, wherein, The isolating switch circuit further comprises a fourth resistor; The first end of the fourth resistor is connected with the power supply end of the switch body, and the second end of the fourth resistor is used to be connected with the power voltage port.

10. A battery management system, characterized by, The battery management system comprises a micro control unit, an insulation detection circuit and a voltage detection circuit, wherein the insulation detection circuit and the voltage detection circuit are connected with the battery pack respectively, the insulation detection circuit and the voltage detection circuit respectively comprise the isolating switch circuit according to any one of claims 5-9, and the micro control unit is connected with each isolating switch circuit respectively. The micro control unit is used to control the on-off of each isolating switch circuit, so that the insulation detection circuit performs insulation detection on the battery pack, and the voltage detection circuit performs voltage detection on the battery pack.

11. The battery management system of claim 10, wherein, The insulation detection circuit comprises a first isolating switch circuit and a second isolating switch circuit; The first end of the first isolating switch circuit is connected with the micro control unit, the second end of the first isolating switch circuit is connected with the positive electrode of the battery pack, and the third end of the first isolating switch circuit is connected with the second end of the second isolating switch circuit. The first end of the second isolating switch circuit is connected with the micro control unit, and the third end of the second isolating switch circuit is connected with the negative electrode of the battery pack. The micro control unit is used to control the on-off of the first isolating switch circuit and the second isolating switch circuit, so that the insulation detection circuit performs insulation detection on the battery pack, and the on time of the first isolating switch circuit and the second isolating switch circuit is opposite.

12. The battery management system of claim 10, wherein, The voltage detection circuit comprises a third isolating switch circuit; The first end of the third isolating switch circuit is connected with the micro control unit, the second end of the third isolating switch circuit is connected with the positive electrode of the battery pack, and the third end of the third isolating switch circuit is connected with the negative electrode of the battery pack. The micro control unit is used to control the on-off of the third isolating switch circuit, so that the voltage detection circuit performs voltage detection on the battery pack.

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