Insulation impedance detection device and detection method for a dc-dc converter

Abstract

The application discloses a kind of DC-DC converter insulation impedance detection device and detection method.The device includes DC-DC converter, power panel, first switching circuit and control module, DC-DC converter includes first insulation detection circuit, second insulation detection circuit, first power port and second power port, first insulation detection circuit, first power port and power panel constitute first power path, second insulation detection circuit, second power port and power panel constitute second power path;First switching circuit is set on first power path or second power path;Control module is connected with first switching circuit, for controlling first switching circuit cut-off before first insulation detection circuit or second insulation detection circuit works, make and first switching circuit first power path or second power path of being located is disconnected.Thereby, first insulation detection circuit or second insulation detection circuit obtains accurate ground insulation impedance detection result.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power electronic converters, in particular to an insulation impedance detection device and method for a DC-DC converter. BACKGROUND

[0002] A DC-DC converter is an electronic device that converts DC power from one voltage value to another voltage value, and is widely used in electronic devices and power systems. The DC-DC converter has an input port and an output port (or referred to as a low-voltage port and a high-voltage port), and the power supply of the DC-DC converter needs to be taken from both ends (to prevent the control system from losing power and the module from being offline due to power loss at one end).

[0003] Currently, there are two schemes for power supply power taking: the first scheme is to use two power supply boards to take power from the input port and the output port respectively, but this scheme has high cost and large size. The second scheme is to use one power supply board to take power from the input port and the output port at the same time through the reverse diode, which has low cost and small size, but this scheme also has problems in actual application, that is, when the DC-DC converter is connected to the power supply board, it needs to have an insulation impedance detection function to detect the insulation impedance of the power supply board to the ground PE (Protecting Earthing), at this time, the insulation impedance detection circuit inside the DC-DC converter is connected to the input port or the output port (or the DC-DC converter has two insulation impedance detection circuits inside, which are connected to the input port and the output port respectively), when the insulation impedance detection circuit works, when detecting the insulation impedance of the ground PE connected to one port, due to the existence of the reverse diode of the power supply board (the impedance of the diode is 0 when working), the insulation impedance of the ground PE of the other port will be detected at the same time, resulting in inaccurate detection results. SUMMARY

[0004] The embodiments of the present application aim to provide an insulation impedance detection device and method for a DC-DC converter, which can solve the problem that due to the existence of the reverse diode on one power supply board, when detecting the insulation impedance of one port, the insulation impedance of the other port will be detected at the same time, resulting in inaccurate detection results.

[0005] To solve the above technical problems, the first aspect of the present application provides an insulation impedance detection device of a DC-DC converter, comprising a DC-DC converter and a power panel, the DC-DC converter comprising a first insulation detection circuit, a second insulation detection circuit, a first power taking port and a second power taking port, a first power taking path comprising the first insulation detection circuit, the first power taking port and the power panel, and a second power taking path comprising the second insulation detection circuit, the second power taking port and the power panel; the insulation impedance detection device of the DC-DC converter further comprises a first switch circuit and a control module; wherein:

[0006] The first switch circuit is arranged on the first power taking path or the second power taking path.

[0007] The control module is electrically connected with the first switch circuit, and is configured to control the first switch circuit to be cut off before the first insulation detection circuit or the second insulation detection circuit performs insulation impedance detection work, so as to disconnect the first power taking path or the second power taking path where the first switch circuit is arranged.

[0008] Optionally, the control module is configured to control the first switch circuit to be cut off before the first insulation detection circuit or the second insulation detection circuit performs insulation impedance detection work, so as to disconnect the first power taking path or the second power taking path where the first switch circuit is arranged, comprising:

[0009] If the first switch circuit is arranged on the first power taking path, the control module controls the first switch circuit to be cut off before the second insulation detection circuit performs insulation impedance detection work, so as to disconnect the first power taking path, and the second insulation detection circuit performs insulation impedance detection work through the second power taking path; or,

[0010] If the first switch circuit is arranged on the second power taking path, the control module controls the first switch circuit to be cut off before the first insulation detection circuit performs insulation impedance detection work, so as to disconnect the second power taking path, and the first insulation detection circuit performs insulation impedance detection work through the first power taking path.

[0011] Optionally, the insulation impedance detection device of the DC-DC converter further comprises a first diode, a second diode, a third diode and a fourth diode, the first diode and the third diode are arranged in the first power taking path, and the second diode and the fourth diode are arranged in the second power taking path.

[0012] Optionally, if the first switch circuit is arranged on the first power taking path, if the power taking position of the first insulation detection circuit is at the first power taking positive port of the first power taking port, the anode of the first diode is connected to the first power taking positive port of the first power taking port, the cathode of the first diode is connected to the first switch circuit, the anode of the third diode is connected to the power supply board, and the cathode of the third diode is connected to the first power taking negative port of the first power taking port; or, if the power taking position of the first insulation detection circuit is at the first power taking negative port of the first power taking port, the anode of the first diode is connected to the first power taking positive port of the first power taking port, the cathode of the first diode is connected to the power supply board, the anode of the third diode is connected to the first switch circuit, and the cathode of the third diode is connected to the first power taking negative port of the first power taking port; the anode of the second diode is connected to the second power taking positive port of the second power taking port, the cathode of the second diode is connected to the power supply board, the anode of the fourth diode is connected to the power supply board, and the cathode of the fourth diode is connected to the second power taking negative port of the second power taking port; or,

[0013] If the first switch circuit is arranged on the second power taking path, if the power taking position of the second insulation detection circuit is at the second power taking positive port of the second power taking port, the anode of the second diode is connected to the second power taking positive port of the second power taking port, the cathode of the second diode is connected to the first switch circuit, the anode of the fourth diode is connected to the power supply board, and the cathode of the fourth diode is connected to the second power taking negative port of the second power taking port; or, if the power taking position of the second insulation detection circuit is at the second power taking negative port of the second power taking port, the anode of the second diode is connected to the second power taking positive port of the second power taking port, the cathode of the second diode is connected to the power supply board, the anode of the fourth diode is connected to the first switch circuit, and the cathode of the fourth diode is connected to the second power taking negative port of the second power taking port; the anode of the first diode is connected to the first power taking positive port of the first power taking port, the cathode of the first diode is connected to the power supply board, the anode of the third diode is connected to the power supply board, and the cathode of the third diode is connected to the first power taking negative port of the first power taking port.

[0014] Optionally, the first switch circuit comprises a first MOS tube and a first alternating current relay, and the first MOS tube and the first alternating current relay are connected in series.

[0015] Optionally, if the first switch circuit is arranged on the first power taking path, if the power taking position of the first insulation detection circuit is at the first power taking positive port of the first power taking port, the drain of the first MOS tube is connected to the negative pole of the first diode, the positive pole of the first diode is connected to the first power taking positive port of the first power taking port, the source of the first MOS tube is connected to the first AC relay and then to the power panel, and the gate of the first MOS tube is connected to the control module; or, if the power taking position of the first insulation detection circuit is at the first power taking negative port of the first power taking port, the drain of the first MOS tube is connected to the first AC relay and then to the power panel, the source of the first MOS tube is connected to the positive pole of the third diode, the negative pole of the third diode is connected to the first power taking negative port of the first power taking port, and the gate of the first MOS tube is connected to the control module.

[0016] If the first switch circuit is arranged on the second power taking path, if the power taking position of the second insulation detection circuit is at the second power taking positive port of the second power taking port, the drain of the first MOS tube is connected to the negative pole of the second diode, the positive pole of the second diode is connected to the second power taking positive port of the second power taking port, the source of the first MOS tube is connected to the first AC relay and then to the power panel, and the gate of the first MOS tube is connected to the control module; or, if the power taking position of the second insulation detection circuit is at the second power taking negative port of the second power taking port, the drain of the first MOS tube is connected to the first AC relay and then to the power panel, the source of the first MOS tube is connected to the positive pole of the fourth diode, the negative pole of the fourth diode is connected to the second power taking negative port of the second power taking port, and the gate of the first MOS tube is connected to the control module.

[0017] Optionally, the insulation impedance detection device of the DC-DC converter further comprises a second switch circuit, the second switch circuit is arranged on the second power taking path, and the second power taking path comprises the second insulation detection circuit, the second power taking port, the second switch circuit and the power panel.

[0018] The first switch circuit is arranged on the first power taking path, and the first power taking path comprises the first insulation detection circuit, the first power taking port, the first switch circuit and the power panel.

[0019] The control module is electrically connected with the second switch circuit, and before the first insulation detection circuit or the second insulation detection circuit performs insulation impedance detection work, the control module controls the first switch circuit or the second switch circuit to be cut off, so that the first power supply path or the second power supply path is disconnected.

[0020] Optionally, before the first insulation detection circuit or the second insulation detection circuit performs insulation impedance detection work, the control module controls the first switch circuit or the second switch circuit to be cut off, so that the first power supply path or the second power supply path is disconnected, and the method comprises the following steps of:

[0021] Before the first insulation detection circuit performs insulation impedance detection work, the control module controls the second switch circuit to be cut off, so that the second power supply path is disconnected, and the first insulation detection circuit performs insulation impedance detection work through the first power supply path; or,

[0022] Before the second insulation detection circuit performs insulation impedance detection work, the control module controls the first switch circuit to be cut off, so that the first power supply path is disconnected, and the second insulation detection circuit performs insulation impedance detection work through the second power supply path.

[0023] Optionally, the second switch circuit comprises a second MOS tube and a second alternating current relay, and the second MOS tube and the second alternating current relay are connected in series.

[0024] If the power supply position of the second insulation detection circuit is at the second power supply positive port of the second power supply port, the drain electrode of the second MOS tube is connected to the negative electrode of the second diode, the positive electrode of the second diode is connected to the second power supply positive port of the second power supply port, the source electrode of the second MOS tube is connected to the second alternating current relay and then connected to the power supply board, and the gate electrode of the second MOS tube is connected to the control module; or,

[0025] If the power supply position of the second insulation detection circuit is at the second power supply negative port of the second power supply port, the drain electrode of the second MOS tube is connected to the second alternating current relay and then connected to the power supply board, the source electrode of the second MOS tube is connected to the positive electrode of the fourth diode, the negative electrode of the fourth diode is connected to the second power supply negative port of the second power supply port, and the gate electrode of the second MOS tube is connected to the control module.

[0026] Correspondingly, the second aspect of the present application further provides a DC-DC converter insulation impedance detection method, which is applied to the DC-DC converter insulation impedance detection device of the first aspect of the present application, and the DC-DC converter insulation impedance detection method comprises the following steps of:

[0027] The first insulation detection circuit, the first power taking port and the power board form a first power taking path, and the second insulation detection circuit, the second power taking port and the power board form a second power taking path.

[0028] The first switch circuit is arranged on the first power taking path or the second power taking path.

[0029] The control module is electrically connected with the first switch circuit, and before the first insulation detection circuit or the second insulation detection circuit performs the insulation impedance detection work, the control module controls the first switch circuit to be cut off, so that the first power taking path or the second power taking path where the first switch circuit is arranged is disconnected.

[0030] Compared with the prior art, the insulation impedance detection device of the DC-DC converter provided by the application is arranged on the first power taking path or the second power taking path through the first switch circuit, which is equivalent to adding a first switch circuit on the first power taking path or the second power taking path, so that the physical isolation of the two ends of the first power taking port and the second power taking port can be realized. The control module is electrically connected with the first switch circuit, and before the first insulation detection circuit or the second insulation detection circuit performs the insulation impedance detection work, the control module controls the first switch circuit to be cut off, so that the first power taking path or the second power taking path where the first switch circuit is arranged is disconnected, so that one of the power taking paths is disconnected and only one of the power taking paths is kept for power taking. Therefore, when the first insulation detection circuit or the second insulation detection circuit performs the detection of the ground insulation impedance of one of the power taking ports, the ground insulation impedance of the other power taking port will not be detected at the same time, so that the first insulation detection circuit or the second insulation detection circuit can accurately perform the detection work and obtain an accurate ground insulation impedance detection result. Therefore, the problem that the ground insulation impedance of one port is detected while the ground insulation impedance of the other port is also detected due to the existence of the reverse diode on one power board, resulting in inaccurate detection result, can be solved. BRIEF DESCRIPTION OF DRAWINGS

[0031] One or more embodiments are illustrated by way of example in the figures that are part of this disclosure and which are illustrative, but not restrictive, of the present embodiments, wherein elements having the same reference numbers designate corresponding elements and wherein the notation "and / or" is used to describe one or more possibilities.

[0032] Figure 1 is a structural schematic view of the insulation impedance detection device of the DC-DC converter provided by the application;

[0033] Figure 2 is another structural schematic view of the insulation impedance detection device of the DC-DC converter provided by the application;

[0034] Figure 3 is a structure schematic diagram of the first switch circuit in the insulation impedance detection device of the DC-DC converter provided by the application, and the first switch circuit is electrically connected to the first power taking positive port to take power when the first switch circuit is arranged in the first power taking path;

[0035] Figure 4 is a structure schematic diagram of the first switch circuit in the insulation impedance detection device of the DC-DC converter provided by the application, and the first switch circuit is electrically connected to the first power taking negative port to take power when the first switch circuit is arranged in the first power taking path;

[0036] Figure 5 is a structure schematic diagram of the first switch circuit in the insulation impedance detection device of the DC-DC converter provided by the application, and the first switch circuit is electrically connected to the second power taking positive port to take power when the first switch circuit is arranged in the second power taking path;

[0037] Figure 6 is a structure schematic diagram of the first switch circuit in the insulation impedance detection device of the DC-DC converter provided by the application, and the first switch circuit is electrically connected to the second power taking negative port to take power when the first switch circuit is arranged in the second power taking path;

[0038] Figure 7 is another structure schematic diagram of the insulation impedance detection device of the DC-DC converter provided by the application;

[0039] Figure 8 is a specific circuit structure schematic diagram of the insulation impedance detection device of the DC-DC converter provided by the application;

[0040] Figure 9 is another specific circuit structure schematic diagram of the insulation impedance detection device of the DC-DC converter provided by the application;

[0041] Figure 10 is a flow schematic diagram of the insulation impedance detection method of the DC-DC converter provided by the application.

[0042] The following is shown in the drawing:

[0043] The insulation impedance detection device 100 of the DC-DC converter, the DC-DC converter 10, the power supply board 20, the first insulation detection circuit F1, the second insulation detection circuit F2, the first power taking port J1, the second power taking port J2, the first power taking path L1, the second power taking path L2, the first switch circuit K1, the control module 30, the first power taking positive port J1+, the first power taking negative port J1-, the second power taking positive port J2+, the second power taking negative port J2-, the first MOS tube Q1, the first alternating current relay T1, the first diode D1, the second switch circuit K2, the second MOS tube Q2, the second alternating current relay T2, the second diode D2, the first control output end 31, and the second control output end 32. DETAILED DESCRIPTION

[0044] For the purpose of promoting the understanding of the present application, the present application will be described in further detail below with reference to the drawings and specific embodiments. It needs to be noted that when an element is described as "fixed to" another element, it can be directly on the other element or one or more intermediate elements can be present therebetween. When an element is described as "connected to" another element, it can be directly connected to the other element or one or more intermediate elements can be present therebetween. The terms "upper", "lower", "inner", "outer", "bottom", etc. used in the present specification indicate the orientation or positional relationship shown in the drawings and are only used for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only for the purpose of description and cannot be understood as indicating or implying relative importance.

[0045] Unless otherwise defined, all technical and scientific terms used in the present specification have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used in the present specification includes any and all combinations of one or more related listed items.

[0046] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as there is no conflict between them.

[0047] In one embodiment, as shown in Figure 1 and Figure 2 The present application provides an insulation impedance detection device 100 of a DC-DC converter, comprising: a DC-DC converter 10 and a power panel 20; wherein:

[0048] The DC-DC converter 10 comprises: a first insulation detection circuit F1, a second insulation detection circuit F2, a first power taking port J1 and a second power taking port J2; the first insulation detection circuit F1, the first power taking port J1 and the power panel 20 constitute a first power taking path L1; the second insulation detection circuit F2, the second power taking port J2 and the power panel 20 constitute a second power taking path L2;

[0049] The insulation impedance detection device 100 of the DC-DC converter further comprises: a first switching circuit K1 and a control module 30; wherein:

[0050] The first switching circuit K1 is arranged on the first power taking path L1 or the second power taking path L2;

[0051] The control module 30 is electrically connected with the first switch circuit K1, and is configured to control the first switch circuit K1 to be turned on or turned off. Before the first insulation detection circuit F1 or the second insulation detection circuit F2 performs the insulation impedance detection work, the control module 30 controls the first switch circuit K1 to be turned off, so that the first power supply path L1 or the second power supply path L2 where the first switch circuit K1 is located is disconnected.

[0052] In the embodiment, the insulation impedance detection device of the DC-DC converter is provided, which is arranged on the first power supply path or the second power supply path through the first switch circuit. The first switch circuit is equivalent to an additional first switch circuit arranged on the first power supply path or the second power supply path, so that the physical isolation of the two ends of the first power supply port and the second power supply port can be realized. The control module is electrically connected with the first switch circuit. Before the first insulation detection circuit or the second insulation detection circuit performs the insulation impedance detection work, the control module controls the first switch circuit to be turned off, so that the first power supply path or the second power supply path where the first switch circuit is located is disconnected. Thus, one of the power supply paths is disconnected, and only one of the power supply paths is used for power supply. When the first insulation detection circuit or the second insulation detection circuit detects the insulation impedance between the ground and one of the power supply ports, the insulation impedance between the ground and the other power supply port will not be detected at the same time. Thus, the first insulation detection circuit or the second insulation detection circuit can accurately perform the detection work, and the accurate insulation impedance detection result can be obtained. Thus, the problem that the insulation impedance of one port is detected while the insulation impedance of the other port is also detected due to the existence of the reverse diode on the power supply board, and the detection result is inaccurate can be solved.

[0053] In one embodiment, before the first insulation detection circuit F1 or the second insulation detection circuit F2 performs the insulation impedance detection work, the control module 30 controls the first switch circuit K1 to be turned off, so that the first power supply path L1 or the second power supply path L2 where the first switch circuit K1 is located is disconnected.

[0054] Specifically, the first power supply path L1 and the second power supply path L2 in the insulation impedance detection device 100 of the DC-DC converter are in the on state by default, that is, the first switch circuit K1 is in the on state by default.

[0055] As shown in FIG. 1, the insulation impedance detection device 100 of the DC-DC converter comprises a first insulation detection circuit F1, a second insulation detection circuit F2, a first switch circuit K1, a second switch circuit K2, a control module 30, a first power supply path L1 and a second power supply path L2. Figure 1As shown, if the first switching circuit K1 is installed on the first power supply path L1, then the first insulation detection circuit F1, the first power supply port J1, the first switching circuit K1, and the power board 20 constitute the first power supply path L1. Before the second insulation detection circuit F2 performs insulation impedance detection, the control module 30 controls the first switching circuit K1 to turn off, thus disconnecting the first power supply path L1. At this time, the second insulation detection circuit F2 performs insulation impedance detection through the second power supply path L2. After the second insulation detection circuit F2 completes the insulation impedance detection, the control module 30 controls the first switching circuit K1 to turn on, thus turning on the first power supply path L1, thereby continuing to keep the first power supply path L1 and the second power supply path L2 in a conducting power supply state. Alternatively,

[0056] like Figure 2 As shown, if the first switching circuit K1 is set on the second power supply path L2, then the second insulation detection circuit F2, the second power supply port J2, the first switching circuit K1, and the power board 20 constitute the second power supply path L2. Before the first insulation detection circuit F1 performs the insulation impedance detection, the control module 30 controls the first switching circuit K1 to turn off, thus disconnecting the second power supply path L2. At this time, the first insulation detection circuit F1 performs the insulation impedance detection through the first power supply path L1. After the first insulation detection circuit F1 completes the insulation impedance detection, the control module 30 controls the second switching circuit K2 to turn on, thus continuing to keep the first power supply path L1 and the second power supply path L2 in a conducting power supply state.

[0057] In this embodiment, by setting the first switching circuit on the first power supply path or the second power supply path, physical isolation between the power supply ends of the first power supply port and the second power supply port can be achieved. The control module is electrically connected to the first switching circuit. Before the first insulation detection circuit or the second insulation detection circuit performs insulation impedance detection, the control module controls the first switching circuit to be turned off, disconnecting it from the first power supply path or the second power supply path. This allows one power supply path to be disconnected, leaving only one power supply path available. Thus, when the first insulation detection circuit or the second insulation detection circuit performs the detection of the insulation impedance to ground of one power supply port, it will not simultaneously detect the insulation impedance to ground of the other power supply port. This allows the first insulation detection circuit or the second insulation detection circuit to perform the detection work accurately and obtain accurate insulation impedance to ground detection results.

[0058] In one embodiment, the DC-DC converter 10 includes: a first insulation detection circuit F1, a second insulation detection circuit F2, a first power supply port J1, and a second power supply port J2.

[0059] Specifically, such as Figures 3 to 9As shown, the first power supply port J1 includes a first positive power supply port J1+ and a first negative power supply port J1-, and the second power supply port J2 includes a second positive power supply port J2+ and a second negative power supply port J2-.

[0060] In one embodiment, such as Figures 3 to 9 As shown, the insulation resistance detection device 100 of the DC-DC converter further includes: a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4. The first diode D1 and the third diode D3 are disposed in the first power supply path L1, and the second diode D2 and the fourth diode D4 are disposed in the second power supply path.

[0061] Specifically, the pin connections of the first diode D1, the second diode D2, the third diode D3, and the fourth diode D4 are related to the power-taking position of the first insulation detection circuit F1 or the second insulation detection circuit F2, as follows:

[0062] like Figure 3 and Figure 4 As shown, if the first switching circuit K1 is set on the first power supply path L1, and if the power supply position of the first insulation detection circuit F1 is the first positive power supply port J1+ of the first power supply port J1, then the anode of the first diode D1 is connected to the first positive power supply port J1+, the cathode of the first diode D1 is connected to the first switching circuit K1, the anode of the third diode D3 is connected to the power board 20, and the cathode of the third diode D3 is connected to the first negative power supply port J1-; or, if the power supply position of the first insulation detection circuit F1 is the first positive power supply port J1+ of the first power supply path L1, then the anode of the first diode D1 is connected to the first positive power supply port J1+, the cathode of the first diode D1 is connected to the first negative power supply port J1-; If the negative terminal J1- is connected, then the anode of the first diode D1 is connected to the first positive terminal J1+, and the cathode of the first diode D1 is connected to the power board 20; the anode of the third diode D3 is connected to the first switching circuit K1, and the cathode of the third diode D3 is connected to the first negative terminal J1-; the anode of the second diode D2 is connected to the second positive terminal J2+, and the cathode of the second diode D2 is connected to the power board 20; the anode of the fourth diode D4 is connected to the power board 20, and the cathode of the fourth diode D4 is connected to the second negative terminal J2-. Alternatively,

[0063] like Figure 5 and Figure 6As shown, if the first switch circuit K1 is arranged on the second power taking path L2, if the power taking position of the second insulation detection circuit F2 is at the second power taking positive port J2+, the anode of the second diode D2 is connected to the second power taking positive port J2+, the cathode of the second diode D2 is connected to the first switch circuit K1, the anode of the fourth diode D4 is connected to the power board 20, and the cathode of the fourth diode D4 is connected to the second power taking negative port J2-; or, if the power taking position of the second insulation detection circuit F2 is at the second power taking negative port J2-, the anode of the second diode D2 is connected to the second power taking positive port J2+, the cathode of the second diode D2 is connected to the power board 20, the anode of the fourth diode D4 is connected to the first switch circuit K1, and the cathode of the fourth diode D4 is connected to the second power taking negative port J2-; the anode of the first diode D1 is connected to the first power taking positive port J1+, the cathode of the first diode D1 is connected to the power board 20, the anode of the third diode D3 is connected to the power board 20, and the cathode of the third diode D3 is connected to the first power taking negative port J1-.

[0064] In the embodiment, for the first power taking path L1, the third diode D3 and the fourth diode D4 are the inverse top diodes of the first power taking path L1. For the second power taking path L2, the first diode D1 and the second diode D2 are the inverse top diodes of the second power taking path L2.

[0065] In one embodiment, the insulation impedance detection device 100 of the DC-DC converter comprises: a first switch circuit K1.

[0066] Specifically, as shown, Figures 3 to 9 the first switch circuit K1 comprises: a first MOS tube Q1 and a first AC relay T1, and the first MOS tube Q1 and the first AC relay T1 are in series. Since the first MOS tube Q1 and the first AC relay T1 are in series, the positions of the first MOS tube Q1 and the first AC relay T1 in the first power taking path L1 can be interchanged. In the embodiment, the first MOS tube Q1 is in front and the first AC relay T1 is in back, that is, the first insulation detection circuit F1, the first power taking port J1, the first MOS tube Q1, the first AC relay T1 and the power board 20 form the first power taking path L1, or the second insulation detection circuit F2, the second power taking port J2, the first MOS tube Q1, the first AC relay T1 and the power board 20 form the second power taking path L2. In the present application, the first AC relay T1 is a normally closed AC relay.

[0067] Further, the pin connection of the first MOS tube Q1 is related to the power taking position of the first insulation detection circuit F1 or the second insulation detection circuit F2, and specifically:

[0068] As shown in Figure 3 and Figure 4 If the first switch circuit K1 is set on the first power taking path L1, if the power taking position of the first insulation detection circuit F1 is at the first power taking positive port J1+ of the first power taking port J1, the drain D of the first MOS Q1 is connected to the negative pole of the first diode D1, the positive pole of the first diode D1 is connected to the first power taking positive port J1+, the source S of the first MOS Q1 is connected to the first AC relay T1 and then to the power board 20, and the gate G of the first MOS Q1 is connected to the first control output end of the control module 30; or, if the power taking position of the first insulation detection circuit F1 is at the first power taking negative port J1- of the first power taking port J1, the drain D of the first MOS Q1 is connected to the first AC relay T1 and then to the power board 20, the source S of the first MOS Q1 is connected to the positive pole of the third diode D3, the negative pole of the third diode D3 is connected to the first power taking negative port J1-, and the gate G of the first MOS Q1 is connected to the first control output end 31 of the control module 30.

[0069] As shown in Figure 5 and Figure 6 If the first switch circuit K1 is set on the second power taking path L2, if the power taking position of the second insulation detection circuit F2 is at the second power taking positive port J2+ of the second power taking port J2, the drain D of the first MOS Q1 is connected to the negative pole of the second diode D2, the positive pole of the second diode D2 is connected to the second power taking positive port J2+, the source S of the first MOS Q1 is connected to the first AC relay T1 and then to the power board 20, and the gate G of the first MOS Q1 is connected to the first control output end of the control module 30; or, if the power taking position of the second insulation detection circuit F2 is at the second power taking negative port J2- of the second power taking port J2, the drain D of the first MOS Q1 is connected to the first AC relay T1 and then to the power board 20, the source S of the first MOS Q1 is connected to the positive pole of the fourth diode D4, the negative pole of the fourth diode D4 is connected to the second power taking negative port J2-, and the gate G of the first MOS Q1 is connected to the first control output end 31 of the control module 30.

[0070] In the present application, the first power taking path L1 and the second power taking path L2 in the insulation impedance detection device 100 of the DC-DC converter are in the conducting power taking state by default, that is, the first switch circuit K1 is in the conducting state by default, and the first MOS Q1 in the first switch circuit K1 and the first AC relay T1 are also in the conducting state by default. The first AC relay T1 and the first MOS Q1 are only disconnected when the first insulation detection circuit F1 and / or the second insulation detection circuit F2 is performing the insulation impedance detection work, and are in the closed state at other times, keeping the first power taking path L1 and the second power taking path L2 in the conducting power taking state.

[0071] It is understood that the first MOSFET Q1 can be a PMOS or NMOS transistor. Since MOSFETs are electronic switches that can be controlled to turn on and off under voltage and load, the first MOSFET Q1 of this invention can be replaced by an electronic switch with equivalent function. For example, an IGBT (Insulated-Gate Bipolar Transistor) can be used to replace the first MOSFET Q1. This invention does not impose any limitations.

[0072] In one embodiment, such as Figures 7 to 9 As shown, the insulation impedance detection device 100 of the DC-DC converter further includes: a second switching circuit K2, which is disposed on the second power supply path L2. The second power supply path L2 includes a second insulation detection circuit F2, a second power supply port J2, the second switching circuit K2, and a power supply board 20.

[0073] The first switching circuit K1 is set on the first power supply path L1, which includes a first insulation detection circuit F1, a first power supply port J1, the first switching circuit K1, and a power board 20.

[0074] The control module 30 is electrically connected to the second switching circuit K2 and is used to control the second switching circuit K2 to be turned on or off.

[0075] Before the first insulation detection circuit F1 or the second insulation detection circuit F2 performs insulation impedance detection, the control module 30 controls the first switching circuit K1 or the second switching circuit K2 to turn off, thereby disconnecting the first power supply path L1 or the second power supply path L2. Specifically:

[0076] Before the first insulation detection circuit F1 performs insulation impedance detection, the control module 30 controls the second switch circuit K2 to turn off, thus disconnecting the second power supply path L2. At this time, the first insulation detection circuit F1 performs insulation impedance detection through the first power supply path L1. After the first insulation detection circuit F1 completes the insulation impedance detection, the control module 30 controls the second switch circuit K2 to turn on, thus turning on the second power supply path L2, thereby continuing to keep the first power supply path L1 and the second power supply path L2 in a conducting power supply state. Alternatively,

[0077] Before the second insulation detection circuit F2 performs the insulation impedance detection work, the control module 30 controls the first switch circuit K1 to be off so as to disconnect the first power taking path L1, at this time, the second insulation detection circuit F2 performs the insulation impedance detection work through the second power taking path L2; after the second insulation detection circuit F2 completes the insulation impedance detection work, the control module 30 controls the first switch circuit K1 to be on so as to connect the first power taking path L1, thereby continuing to keep the first power taking path L1 and the second power taking path L2 in the on power taking state.

[0078] In the embodiment, the insulation impedance detection device of the DC-DC converter is provided, the first switch circuit is arranged on the first power taking path, which is equivalent to adding a first switch circuit on the first power taking path, so that the first insulation detection circuit, the first power taking port, the first switch circuit and the power board form the first power taking path, the second switch circuit is arranged on the second power taking path, which is equivalent to adding a second switch circuit on the second power taking path, so that the second insulation detection circuit, the second power taking port, the second switch circuit and the power board form the second power taking path, thereby realizing the physical isolation of the two ends of the first power taking port and the second power taking port; the control module is electrically connected with the first switch circuit and the second switch circuit respectively, when the first insulation detection circuit performs the insulation impedance detection work, the control module controls the second switch circuit to be off so as to disconnect the second power taking path, at this time, the first insulation detection circuit performs the insulation impedance detection work through the first power taking path; before the second insulation detection circuit performs the insulation impedance detection work, the control module controls the first switch circuit to be off so as to disconnect the first power taking path, at this time, the second insulation detection circuit performs the insulation impedance detection work through the second power taking path, thereby realizing the disconnection of one of the power taking paths and the power taking of the other power taking path, so that when the first insulation detection circuit or the second insulation detection circuit performs the detection of the ground insulation impedance of one of the power taking ports, the ground insulation impedance of the other power taking port will not be detected at the same time, thereby enabling the first insulation detection circuit or the second insulation detection circuit to accurately perform the detection work and obtain the accurate ground insulation impedance detection result. Thus, the problem that the ground insulation impedance of one port is detected while the ground insulation impedance of the other port is also detected due to the existence of the inverse top diode on the power board, thereby resulting in the inaccurate detection result, can be solved.

[0079] In one embodiment, as Figure 8 and Figure 9As shown, the second switching circuit K2 includes a second MOSFET Q2 and a second AC relay T2, which are connected in series. Since the second MOSFET Q2 and the second AC relay T2 are connected in series, their positions in the second power supply path L2 can be interchanged. In this embodiment, the second MOSFET Q2 is described first, followed by the second AC relay T2, meaning that the second insulation detection circuit F2, the second power supply port J2, the second MOSFET Q2, the second AC relay T2, and the power board 20 constitute the second power supply path L2. In this invention, the second AC relay T2 is a normally closed AC relay.

[0080] Furthermore, the pin configuration of the second MOSFET Q2 is related to the power-taking position of the second insulation detection circuit F2, specifically as follows:

[0081] like Figure 8 As shown, if the power supply position of the second insulation detection circuit F2 is the second positive power supply port J2+ of the second power supply port J2, then the drain D of the second MOS transistor Q2 is connected to the second positive power supply port J2+, the source S of the second MOS transistor Q2 is connected to the second AC relay T2 and then to the power supply board 20, and the gate G of the second MOS transistor Q2 is connected to the second control output terminal 32 of the control module 30. Specifically, the second power supply path L2 includes a second insulation detection circuit F2, a second positive power supply port J2+ of the second power supply port J2, a second diode D2, a second MOSFET Q2, a second AC relay T2, a power supply board 20, a fourth diode D4, a second negative power supply port J2- of the second power supply port J2, and the second insulation detection circuit F2. The anode of the second diode D2 is connected to the second positive power supply port J2+, the cathode of the second diode D2 is connected to the drain D of the second MOSFET Q2, the gate G of the second MOSFET Q2 is connected to the second control output terminal 32 of the control module 30, the source S of the second MOSFET Q2 is connected to the second AC relay T2 and then to the power supply board 20, the anode of the fourth diode D4 is connected to the power supply board 20, and the cathode of the fourth diode D4 is connected to the second negative power supply port J2-. Alternatively,

[0082] like Figure 9As shown, if the power taking position of the second insulation detection circuit F2 is the second power taking negative port J2- of the second power taking port J2, the drain D of the second MOS tube Q2 is connected to the second AC relay T2 and then to the power board 20, the source S is connected to the second power taking negative port J2-, and the gate G is connected to the second control output end 32 of the control module 30. Specifically, the second power taking path L2 includes the second insulation detection circuit F2, the second power taking positive port J2+ of the second power taking port J2, the second diode D2, the power board 20, the second AC relay T2, the second MOS tube Q2, the fourth diode D4, the second power taking negative port J2- of the second power taking port J2, and the second insulation detection circuit F2; the anode of the second diode D2 is connected to the second power taking positive port J2+, the cathode of the second diode D2 is connected to the power board 20, the drain D of the second MOS tube Q2 is connected to the second AC relay T2 and then to the power board 20, the gate G of the second MOS tube Q2 is connected to the second control output end 32 of the control module 30, the source S of the second MOS tube Q2 is connected to the anode of the fourth diode D4, and the cathode of the fourth diode D4 is connected to the second power taking negative port J2-.

[0083] In the present application, the first power taking path L1 and the second power taking path L2 in the insulation impedance detection device 100 of the DC-DC converter are in the power taking state by default, i.e., the second switch circuit K2 is in the on state by default, and the second MOS tube Q2 and the second AC relay T2 in the second switch circuit K2 are also in the on state by default. The second AC relay T2 and the second MOS tube Q2 are only disconnected when the first insulation detection circuit F1 and / or the second insulation detection circuit F2 performs the insulation impedance detection work, and are in the closed state at other times, so as to keep the first power taking path L1 and the second power taking path L2 in the power taking state.

[0084] It can be understood that the second MOS tube Q2 can be a PMOS tube or an NMOS tube. Since the MOS tube is an electronic switch that can control the on-off state with voltage and load, the second MOS tube Q2 in the present application can be replaced by an electronic switch with the same function, for example, an IGBT (Insulate-Gate Bipolar Transistor) can be used to replace the second MOS tube Q2, and the present application is not limited in this regard.

[0085] In the application, if the relay is selected as a direct current relay, the size is large and the cost is high, therefore, the relay in the application selects an alternating current relay with small size and low cost, the first alternating current relay T1 and / or the second alternating current relay T2 are both normally closed alternating current relays. The application is connected in series with the first MOS tube Q1 or IGBT electronic switching device and the first alternating current relay T1, and / or connected in series with the second MOS tube Q2 or IGBT electronic switching device and the second alternating current relay T2, the direct current part is first switched by the MOS tube or IGBT, and then switched by the alternating current relay to achieve physical isolation of the two ends of the first power port and the second power port, thereby solving the problem that the existing detection of the insulation impedance of a port will simultaneously detect the insulation impedance of another port due to the existence of the reverse diode on the power board, resulting in inaccurate detection results. Compared with the common method of using two power boards for the first power port and the second power port to achieve insulation detection isolation of the two ends, the cost of the insulation impedance detection device is greatly saved, the size of the insulation impedance detection device is reduced, and the problem of using a large size and high cost direct current relay on the direct current side is solved by connecting the second MOS tube Q2 or IGBT electronic switching device and the alternating current relay in series.

[0086] In one embodiment, the insulation impedance detection device 100 of the direct current-direct current converter comprises a control module 30 electrically connected with the first switching circuit K1 and the second switching circuit K2 respectively, used for controlling the first switching circuit K1 or the second switching circuit K2 to be turned on or turned off, so as to turn on or turn off the first power path L1 or the second power path L2.

[0087] Specifically, before the first insulation detection circuit F1 performs the insulation impedance detection work, the control module 30 controls the second switching circuit K2 to be turned off to disconnect the second power path L2, and then controls the first switching circuit K1 to be turned on to turn on the first power path L1; after the first insulation detection circuit F1 completes the insulation impedance detection work, the control module 30 controls the second switching circuit K2 to be turned on to turn on the second power path L2, and keeps the first power path L1 and the second power path L2 to be powered. Alternatively,

[0088] Before the second insulation detection circuit F2 performs the insulation impedance detection work, the control module 30 controls the first switching circuit K1 to be turned off to disconnect the first power path L1, and then controls the second switching circuit K2 to be turned on to turn on the second power path L2; after the second insulation detection circuit F2 completes the insulation impedance detection work, the control module 30 controls the first switching circuit K1 to be turned on to turn on the first power path L1, and keeps the first power path L1 and the second power path L2 to be powered.

[0089] Further, as Figure 8 and Figure 9As shown, the control module 30 includes: a first control output terminal 31 and a second control output terminal 32.

[0090] The first control output terminal 31 is electrically connected to the first switching circuit K1. Specifically, the first control output terminal 31 is connected to the gate G of the first MOS transistor Q1 to control the conduction or cutoff of the first MOS transistor Q1, thereby controlling the conduction or cutoff of the first power supply path L1.

[0091] The second control output terminal 32 is electrically connected to the second switching circuit K2. Specifically, the second control output terminal 32 is connected to the gate G of the second MOS transistor Q2 to control the conduction or cutoff of the second MOS transistor Q2, thereby controlling the conduction or cutoff of the second power supply path L2.

[0092] In this invention, the first AC relay T1, the first MOSFET Q1, the second AC relay T2, and the second MOSFET Q2 are only disconnected when the first insulation detection circuit F1 and / or the second insulation detection circuit F2 are performing insulation impedance detection. At other times, they are in a closed state, keeping both the first power supply path L1 and the second power supply path L2 in a conducting power supply state.

[0093] This invention provides an insulation impedance detection device 100 for a DC-DC converter. Taking the insulation impedance detection operation performed by the first insulation detection circuit F1 as an example, its operation process is described below:

[0094] like Figure 8 As shown, the first power supply path L1 includes a first insulation detection circuit F1, the first positive power supply port J1+ of the first power supply port J1, a first diode D1, a first MOSFET Q1, a first AC relay T1, a power supply board 20, a third diode D3, the first negative power supply port J1- of the first power supply port J1, and the first insulation detection circuit F1; the second power supply path L2 includes a second insulation detection circuit F2, the second positive power supply port J2+ of the second power supply port J2, a second diode D2, a second MOSFET Q2, a second AC relay T2, a power supply board 20, a fourth diode D4, the second negative power supply port J2- of the second power supply port J2, and the second insulation detection circuit F2; the first control output terminal 31 of the control module 30 controls the conduction or cutoff of the first MOSFET Q1 in the first switching circuit K1, and the second control output terminal 32 of the control module 30 controls the conduction or cutoff of the second MOSFET Q2 in the second switching circuit K2.

[0095] The first power taking path L1 and the second power taking path L2 in the insulation impedance detection device 100 of the DC-DC converter are in the conducting power taking state by default, that is, the first MOS tube Q1 in the first switch circuit K1 and the first AC relay T1 are in the conducting state by default, and the second MOS tube Q2 in the second switch circuit K2 and the second AC relay T2 are in the conducting state by default.

[0096] Taking the insulation impedance detection work performed by the first insulation detection circuit F1 as an example, before the insulation impedance detection work performed by the first insulation detection circuit F1, the second control output end 32 of the control module 30 controls the second MOS tube Q2 in the second switch circuit K2 to be off, controls the second AC relay T2 to be disconnected (since the second MOS tube Q2 has disconnected the DC loop in which the second MOS tube Q2 is located at this time, the second AC relay T2 is disconnected without voltage and load, and is responsible for realizing physical disconnection and isolation), and makes the second power taking path L2 disconnected. At this time, the first insulation detection circuit F1 performs the insulation impedance detection work through the first power taking path L1. After the first insulation detection circuit F1 completes the insulation impedance detection work, the second AC relay T2 is closed, and the control module 30 controls the second MOS tube Q2 in the second switch circuit K2, so that the second power taking path L2 is conducted, the first power taking path L1 and the second power taking path L2 are kept in the power taking state, and the insulation impedance detection device 100 of the DC-DC converter enters the normal power taking working state.

[0097] Based on the same concept, in one embodiment, as shown in Figure 10 the application also provides a DC-DC converter insulation impedance detection method, which is applied to the insulation impedance detection device 100 of the DC-DC converter in any of the above embodiments, and includes the following steps:

[0098] S1, the first insulation detection circuit, the first power taking port and the power panel form a first power taking path, and the second insulation detection circuit, the second power taking port and the power panel form a second power taking path;

[0099] S2, the first switch circuit is arranged on the first power taking path or the second power taking path;

[0100] S3, the control module is electrically connected with the first switch circuit, controls the first switch circuit to be conducted or off, and before the first insulation detection circuit or the second insulation detection circuit performs the insulation impedance detection work, the control module controls the first switch circuit to be off, so that the first power taking path or the second power taking path in which the first switch circuit is located is disconnected.

[0101] In the embodiment, an insulation impedance detection method of a DC-DC converter is provided. A first insulation detection circuit, a first power taking port and a power board form a first power taking path, and a second insulation detection circuit, a second power taking port and the power board form a second power taking path. A first switch circuit is arranged on the first power taking path or the second power taking path. A control module is electrically connected with the first switch circuit, and controls the first switch circuit to be turned on or turned off. Before the first insulation detection circuit or the second insulation detection circuit performs an insulation impedance detection work, the control module controls the first switch circuit to be turned off, so that the first power taking path or the second power taking path in which the first switch circuit is arranged is disconnected. Thus, one of the power taking paths is disconnected, and only one of the power taking paths is reserved to take power. When the first insulation detection circuit or the second insulation detection circuit performs detection on the ground insulation impedance of one of the power taking ports, the ground insulation impedance of the other power taking port will not be detected at the same time. Thus, the first insulation detection circuit or the second insulation detection circuit can accurately perform the detection work, and an accurate ground insulation impedance detection result can be obtained. Thus, the problem that the ground insulation impedance of one port is detected while the ground insulation impedance of the other port is also detected due to the existence of a reverse diode on one power board, and the detection result is inaccurate, can be solved.

[0102] It should be noted that the insulation impedance detection method of the DC-DC converter and the insulation impedance detection device of the DC-DC converter belong to the same concept, and the specific implementation process is described in the insulation impedance detection device of the DC-DC converter. The technical features in the insulation impedance detection device of the DC-DC converter are applicable to the insulation impedance detection method of the DC-DC converter, and will not be described here.

[0103] It should be noted that in this document, the term "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that processes, methods, articles or devices including a series of elements not only include those elements, but also include other elements not explicitly listed or inherent to such processes, methods, articles or devices. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or device including the element.

[0104] The above examples are only used to illustrate the technical solutions of the present application, but not to limit the present application; the technical features in the above examples or different examples can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the present application as described above, which are not provided in details for simplicity; although the present application has been described in detail with reference to the foregoing examples, it should be understood by those of ordinary skill in the art that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An insulation impedance detection device for a DC-DC converter, comprising a DC-DC converter and a power board, wherein the DC-DC converter includes a first insulation detection circuit, a second insulation detection circuit, a first power supply port, and a second power supply port; a first power supply path includes the first insulation detection circuit, the first power supply port, and the power board; and a second power supply path includes the second insulation detection circuit, the second power supply port, and the power board; characterized in that, The insulation impedance detection device for the DC-DC converter further includes: a first switching circuit and a control module; wherein: The first switching circuit is disposed on the first power supply path or the second power supply path; The control module is electrically connected to the first switching circuit and is used to control the first switching circuit to turn off before the first insulation detection circuit or the second insulation detection circuit performs insulation impedance detection, thereby disconnecting the first power supply path or the second power supply path where the first switching circuit is located. This includes: if the first switching circuit is located on the first power supply path, the control module controls the first switching circuit to turn off before the second insulation detection circuit performs insulation impedance detection, thus disconnecting the first power supply path, and the second insulation detection circuit performs insulation impedance detection through the second power supply path; or, if the first switching circuit is located on the second power supply path, the control module controls the first switching circuit to turn off before the first insulation detection circuit performs insulation impedance detection, thus disconnecting the second power supply path, and the first insulation detection circuit performs insulation impedance detection through the first power supply path.

2. The insulation impedance detection device for a DC-DC converter according to claim 1, characterized in that, The insulation impedance detection device of the DC-DC converter further includes a first diode, a second diode, a third diode, and a fourth diode. The first diode and the third diode are disposed in the first power supply path, and the second diode and the fourth diode are disposed in the second power supply path.

3. The insulation impedance detection device for a DC-DC converter according to claim 2, characterized in that, If the first switching circuit is located on the first power supply path, and if the power supply position of the first insulation detection circuit is at the first positive power supply port of the first power supply port, then the anode of the first diode is connected to the first positive power supply port of the first power supply port, and the cathode of the first diode is connected to the first switching circuit; the anode of the third diode is connected to the power board, and the cathode of the third diode is connected to the first negative power supply port of the first power supply port; or, if the power supply position of the first insulation detection circuit is at the first negative power supply port of the first power supply port, then the anode of the first diode is connected to the first positive power supply port of the first power supply port, and the cathode of the first diode is connected to the power board; the anode of the third diode is connected to the first switching circuit, and the cathode of the third diode is connected to the first negative power supply port of the first power supply port; the anode of the second diode is connected to the second positive power supply port of the second power supply port, and the cathode of the second diode is connected to the power board; the anode of the fourth diode is connected to the power board, and the cathode of the fourth diode is connected to the second negative power supply port of the second power supply port; or... If the first switching circuit is located on the second power supply path, and if the power supply position of the second insulation detection circuit is at the second positive power supply port of the second power supply port, then the anode of the second diode is connected to the second positive power supply port of the second power supply port, and the cathode of the second diode is connected to the first switching circuit; the anode of the fourth diode is connected to the power board, and the cathode of the fourth diode is connected to the second negative power supply port of the second power supply port. Alternatively, if the power supply position of the second insulation detection circuit is at the second negative power supply port of the second power supply port, then the anode of the second diode is connected to the second positive power supply port of the second power supply port, and the cathode of the second diode is connected to the power board; the anode of the fourth diode is connected to the first switching circuit, and the cathode of the fourth diode is connected to the second negative power supply port of the second power supply port; the anode of the first diode is connected to the first positive power supply port of the first power supply port, and the cathode of the first diode is connected to the power board; the anode of the third diode is connected to the power board, and the cathode of the third diode is connected to the first negative power supply port of the first power supply port.

4. The insulation impedance detection device for a DC-DC converter according to claim 2, characterized in that, The first switching circuit includes a first MOSFET and a first AC relay, wherein the first MOSFET and the first AC relay are connected in series.

5. The insulation impedance detection device for a DC-DC converter according to claim 4, characterized in that, If the first switching circuit is located on the first power supply path, and if the power supply position of the first insulation detection circuit is at the first positive power supply port of the first power supply port, then the drain of the first MOSFET is connected to the cathode of the first diode, the anode of the first diode is connected to the first positive power supply port of the first power supply port, the source of the first MOSFET is connected to the first AC relay and then to the power supply board, and the gate of the first MOSFET is connected to the control module; or, if the power supply position of the first insulation detection circuit is at the first negative power supply port of the first power supply port, then the drain of the first MOSFET is connected to the first AC relay and then to the power supply board, the source of the first MOSFET is connected to the anode of the third diode, the cathode of the third diode is connected to the first negative power supply port of the first power supply port, and the gate of the first MOSFET is connected to the control module; or... If the first switching circuit is located on the second power supply path, and if the power supply position of the second insulation detection circuit is at the second positive power supply port of the second power supply port, then the drain of the first MOS transistor is connected to the negative terminal of the second diode, the positive terminal of the second diode is connected to the second positive power supply port of the second power supply port, the source of the first MOS transistor is connected to the first AC relay and then to the power supply board, and the gate of the first MOS transistor is connected to the control module; or, if the power supply position of the second insulation detection circuit is at the second negative power supply port of the second power supply port, then the drain of the first MOS transistor is connected to the first AC relay and then to the power supply board, the source of the first MOS transistor is connected to the positive terminal of the fourth diode, the negative terminal of the fourth diode is connected to the second negative power supply port of the second power supply port, and the gate of the first MOS transistor is connected to the control module.

6. The insulation impedance detection device for a DC-DC converter according to claim 2, characterized in that, The insulation impedance detection device of the DC-DC converter further includes: a second switching circuit, which is disposed on the second power supply path, and the second power supply path includes the second insulation detection circuit, the second power supply port, the second switching circuit and the power board; The first switching circuit is disposed on the first power supply path, and the first power supply path includes the first insulation detection circuit, the first power supply port, the first switching circuit and the power board; The control module is electrically connected to the second switching circuit. Before the first insulation detection circuit or the second insulation detection circuit performs insulation impedance detection, the control module controls the first switching circuit or the second switching circuit to turn off, thereby disconnecting the first power supply path or the second power supply path.

7. The insulation impedance detection device for a DC-DC converter according to claim 6, characterized in that, Before the first insulation detection circuit or the second insulation detection circuit performs insulation impedance detection, the control module controls the first switch or the second switch circuit to turn off, thereby disconnecting the first power supply path or the second power supply path, including: Before the first insulation detection circuit performs insulation impedance detection, the control module controls the second switching circuit to turn off, thus disconnecting the second power supply path. The first insulation detection circuit then performs insulation impedance detection through the first power supply path; or... Before the second insulation detection circuit performs insulation impedance detection, the control module controls the first switching circuit to turn off, thus disconnecting the first power supply path. The second insulation detection circuit then performs insulation impedance detection through the second power supply path.

8. The insulation impedance detection device for a DC-DC converter according to claim 6, characterized in that, The second switching circuit includes: a second MOSFET and a second AC relay, wherein the second MOSFET and the second AC relay are connected in series; If the power source of the second insulation detection circuit is located at the second positive power source port of the second power source port, then the drain of the second MOSFET is connected to the cathode of the second diode, the anode of the second diode is connected to the second positive power source port of the second power source port, the source of the second MOSFET is connected to the second AC relay and then to the power supply board, and the gate of the second MOSFET is connected to the control module; or... If the power supply position of the second insulation detection circuit is at the second negative power supply port of the second power supply port, then the drain of the second MOS transistor is connected to the second AC relay and then to the power board, the source of the second MOS transistor is connected to the positive terminal of the fourth diode, the negative terminal of the fourth diode is connected to the second negative power supply port of the second power supply port, and the gate of the second MOS transistor is connected to the control module.

9. A method for detecting the insulation impedance of a DC-DC converter, characterized in that, An insulation impedance detection device for a DC-DC converter according to any one of claims 1 to 8, wherein the insulation impedance detection method for the DC-DC converter comprises: The first insulation detection circuit, the first power supply port, and the power board form the first power supply path, and the second insulation detection circuit, the second power supply port, and the power board form the second power supply path. The first switching circuit is set on the first power supply path or the second power supply path; The control module is electrically connected to the first switching circuit. Before the first insulation detection circuit or the second insulation detection circuit performs the insulation impedance detection, the control module controls the first switching circuit to turn off, thereby disconnecting it from the first power supply path or the second power supply path where the first switching circuit is located.

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