Insulation resistance detection circuit and new energy equipment

Abstract

The utility model discloses an insulation resistance detection circuit and new energy equipment. The insulation resistance detection circuit comprises a first resistor, a second resistor, a first switch and a second switch, the first resistor and the first switch are connected in series to form a first detection branch, and the second resistor and the second switch are connected in series to form a second detection branch; the first detection branch and the second detection branch are connected in parallel and then are connected between a negative DC bus and a grounding wire or between a positive DC bus and the grounding wire. According to the insulation resistance detection circuit and the new energy equipment, the insulation resistance detection circuit is composed of the first resistor, the second resistor, the first switch and the second switch, the circuit structure is simple, the cost is low, and the ground insulation resistance of the equipment can be effectively detected.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and in particular to an insulation impedance detection circuit and new energy equipment. Background Art

[0002] New energy equipment, such as photovoltaic inverters and energy storage converters, all have corresponding standards that clearly define the insulation impedance requirements of the equipment. To ensure the safe and reliable operation of the equipment, the insulation impedance of the equipment must be tested to ensure that its impedance to ground meets the requirements of the relevant standards. Utility Model Content

[0003] The purpose of this application is to provide an insulation impedance detection circuit and a new energy device, so as to effectively detect the insulation impedance of the device to ground through a low-cost circuit.

[0004] According to one aspect of the present application, there is provided an insulation impedance detection circuit, comprising a first resistor, a second resistor, a first switch, and a second switch;

[0005] The first resistor and the first switch are connected in series to form a first detection branch, and the second resistor and the second switch are connected in series to form a second detection branch;

[0006] The first detection branch and the second detection branch are connected in parallel and then connected between the negative DC bus and the ground line or between the positive DC bus and the ground line.

[0007] In one example, a control unit is further included, wherein the control unit is configured to control the on or off of the first switch and / or the second switch.

[0008] In one example, the control unit is configured to first control the first switch to be turned on, and then control the first switch and the second switch to be turned on together.

[0009] In one example, the first resistor or the second resistor includes a plurality of resistors connected in series and / or in parallel.

[0010] In one example, the first switch or the second switch includes a transistor or a relay.

[0011] In one example, the transistor includes an IGBT transistor or a MOS transistor.

[0012] According to another aspect of the present application, a new energy device is provided, comprising the above-mentioned insulation impedance detection circuit.

[0013] In one example, the new energy equipment includes a photovoltaic inverter or an energy storage converter.

[0014] The insulation impedance detection circuit and new energy equipment provided in the embodiments of the present application are composed of a first resistor, a second resistor, a first switch and a second switch. The insulation impedance detection circuit has a simple circuit structure and low cost, and can effectively detect the insulation impedance of the equipment to ground. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of an insulation impedance detection circuit provided in an embodiment of the present application;

[0016] Figure 2 A schematic diagram of another insulation impedance detection circuit provided in an embodiment of the present application.

[0017] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application clearer and more understandable, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0019] In the description of this application, it should be understood that the directions or positional relationships indicated by terms such as "center," "upper," "lower," "front," "back," "left," and "right" are based on the directions or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific direction, be constructed, or operate in a specific direction. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] Figure 1 A schematic diagram of an insulation impedance detection circuit provided in an embodiment of the present application.

[0021] like Figure 1 As shown, the insulation resistance detection circuit includes a first resistor R1, a second resistor R2, a first switch K1 and a second switch K2;

[0022] The first resistor R1 and the first switch K1 are connected in series to form a first detection branch, and the second resistor R2 and the second switch are connected in series to form a second detection branch;

[0023] The first detection branch and the second detection branch are connected in parallel and then connected between the negative DC bus DC- and the grounding line PE.

[0024] In one example, a control unit is further included, and the control unit is configured to control the on or off of the first switch K1 and / or the second switch K2.

[0025] In an example, the control unit is configured to first control the first switch to be turned on, and then control the first switch K1 and the second switch K2 to be turned on together.

[0026] In one example, the first resistor R1 or the second resistor R2 includes a plurality of resistors connected in series and / or in parallel.

[0027] In one example, the first switch K1 or the second switch K2 includes a transistor or a relay.

[0028] In one example, the transistor includes an IGBT transistor or a MOS transistor.

[0029] The following Figure 1 The working principle of the insulation resistance detection circuit is explained as follows:

[0030] R in the figure x R is the impedance of the negative DC bus DC- to ground, y R is the impedance of the positive DC bus DC+ to ground. x With R y Series, R1, R2, R x 、R y There is a common terminal, R x There is a common terminal between switches K1 and K2.

[0031] In detecting R x and R y When the first switch K1 is closed, the voltage between the negative DC bus DC- and the ground line PE is detected and recorded as U' DC- The voltage between the positive DC bus DC+ and the ground line PE is recorded as U' DC+ , and we get the following formula:

[0032] Then close the second switch K2, and the voltage between the negative DC bus DC- and the ground line PE is detected, which is recorded as U″ DC- The voltage between the positive DC bus DC+ and the grounding line PE is recorded as U″ DC+ , and we get the following formula:

[0033] The above two formulas can be used to obtain the ground impedance of the positive and negative DC bus DC+: in

[0034] Figure 2 A schematic diagram of another insulation impedance detection circuit provided in an embodiment of the present application.

[0035] and Figure 1 The difference in this example is that the first detection branch and the second detection branch are connected in parallel and then connected between the positive DC bus DC+ and the grounding line PE.

[0036] The following Figure 2 The working principle of the insulation resistance detection circuit is explained as follows:

[0037] R in the figure x R is the impedance of the negative DC bus DC- to ground, y R is the impedance of the positive DC bus DC+ to ground. x With R y Series, R1, R2, R x 、R y There is a common terminal, R y There is a common terminal between switches K1 and K2.

[0038] In detecting R x and R y When the first switch K1 is closed, the voltage between the negative DC bus DC- and the ground line PE is detected and recorded as U' DC- The voltage between the positive DC bus DC+ and the ground line PE is recorded as U' DC+ , and we get the following formula:

[0039] Then close the second switch K2, and the voltage between the negative DC bus DC- and the ground line PE is detected, which is recorded as U″ DC- The voltage between the positive DC bus DC+ and the grounding line PE is recorded as U″ DC+ , and we get the following formula:

[0040] The above two formulas can be used to obtain the ground impedance of the positive and negative DC bus DC+: in

[0041] Yet another embodiment of the present application provides a new energy device, comprising the insulation impedance detection circuit described in the aforementioned embodiment.

[0042] In one example, the new energy equipment includes a photovoltaic inverter or an energy storage converter.

[0043] The preferred embodiments of the present application are described above with reference to the accompanying drawings, but are not intended to limit the scope of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and essence of the present application shall fall within the scope of the present application.

Claims

1. An insulation impedance detection circuit, characterized in that: comprising a first resistor, a second resistor, a first switch and a second switch; The first resistor and the first switch are connected in series to form a first detection branch, and the second resistor and the second switch are connected in series to form a second detection branch; The first detection branch and the second detection branch are connected in parallel and then connected between the negative DC bus and the ground line or between the positive DC bus and the ground line.

2. The insulation resistance detection circuit according to claim 1, wherein: The system further includes a control unit configured to control the on or off of the first switch and / or the second switch.

3. The insulation resistance detection circuit according to claim 2, wherein: The control unit is configured to first control the first switch to be turned on, and then control the first switch and the second switch to be turned on together.

4. The insulation resistance detection circuit according to claim 1, wherein: The first resistor or the second resistor includes a plurality of resistors connected in series and / or in parallel.

5. The insulation resistance detection circuit according to claim 1, wherein: The first switch or the second switch includes a transistor or a relay.

6. The insulation resistance detection circuit according to claim 5, characterized in that: The transistor includes an IGBT tube or a MOS tube.

7. A new energy device, characterized in that: The invention comprises the insulation impedance detection circuit according to any one of claims 1 to 6.

8. The new energy device according to claim 7, characterized in that: The new energy equipment includes a photovoltaic inverter or an energy storage converter.

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