Direct-current power grid conducted emission measuring device

Abstract

The utility model relates to the technical field of filter devices, in particular to a direct-current power grid conducted emission measuring device which comprises a shell, an input interface is arranged at one end of the shell, an output interface is arranged at the other end of the shell, and four cavities are arranged in the shell. The device sequentially comprises an input end wiring area, a power grid conduction measurement function area, a direct current power grid filtering function area and an output end wiring area from left to right, and is characterized in that the power grid conduction measurement function area comprises a current probe and an SMA connector, and the current probe is connected with the SMA connector through a radio frequency coaxial cable; the direct current power grid filtering function area comprises a first capacitor, a second capacitor and a bleeder resistor, the first capacitor and the second capacitor are connected in series, and the bleeder resistor is connected with the first capacitor and the second capacitor in parallel. The device is a multifunctional integrated direct-current power grid conduction emission measuring device.

Description

Technical Field

[0001] The utility model relates to the technical field of filter devices, in particular to a direct current grid conducted emission measuring device. Background Art

[0002] A certain type of system needs to develop a device that can simultaneously filter the DC grid and collect conducted emission data. The original design only has the filtering function but not the function of collecting conducted emission data. Therefore, an improved design is needed to add a separate compartment on the basis of the original filter to realize the function of collecting conducted emission data for the DC grid. How to use the same filter circuit to suppress overvoltage and spike pulse interference problems in the DC grid, collect conducted emission data of the DC grid at the same time, and realize a multifunctional integrated design is a technical problem to be solved. Utility Model Content

[0003] Problem to be solved: Use the same filter circuit to suppress overvoltage and spike pulse interference problems in the DC power grid, and at the same time collect DC power grid conduction emission data to realize a multifunctional integrated DC power grid conduction emission measurement device.

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a DC power grid conduction emission measurement device, comprising a shell, one end of the shell is an input interface, the other end of the shell is an output interface, the shell includes four chambers, from left to right are an input terminal wiring area, a power grid conduction measurement functional area, a DC power grid filtering functional area and an output terminal wiring area, the power grid conduction measurement functional area includes a current probe and an SMA connector, the current probe and the SMA connector are connected through a radio frequency coaxial cable; the DC power grid filtering functional area includes a capacitor 1, a capacitor 2 and a discharge resistor, the capacitor 1 and the capacitor 2 are connected in series, and the discharge resistor is connected in parallel with the capacitor 1 and the capacitor 2.

[0005] Preferably, high-frequency insulating ceramic beads are used as insulating materials at the connections between the four chambers.

[0006] Preferably, the current probe has a clamp-shaped structure and is wound with a material having a stable magnetic permeability.

[0007] Preferably, the SMA connector is a threaded connector.

[0008] Preferably, capacitor 1 and capacitor 2 are connected in series via a conductive copper connecting sheet.

[0009] Preferably, the capacitor 1 and the capacitor 2 are both through-hole capacitors, and the sizes of the capacitor 1 and the capacitor 2 are both 20 μF.

[0010] Preferably, the discharge resistance parameter is 5W / MΩ.

[0011] Preferably, the housing is made of 304 stainless steel plate, the surface of the housing is electroplated with nickel and sprayed with a polyurethane paint layer, and a plurality of mounting parts are provided on the outer surface of the housing.

[0012] Compared with the prior art, the utility model provides a DC grid conducted emission measurement device, which has the following beneficial effects: it is mainly used to suppress overvoltage and spike pulse interference in the DC grid, and at the same time collect DC grid conducted emission data. The collected data can be uploaded to the host computer through the electromagnetic information collection device for comprehensive analysis, display and human-computer interaction. The device of the utility model and the DC grid filter are integrally installed on the DC grid, and the same filter circuit is used to suppress the overvoltage and spike pulse interference problems in the DC grid, and at the same time collect DC grid conducted emission data, realizing the design of multi-functional integration. An acquisition end current probe is added, and the current probe and the main circuit cable are in a non-contact manner, and the electromagnetic induction principle is used to collect the interference in a specific frequency range (25Hz - 10MHz) in the grid. The internal structure of the device of the utility model adopts a multi-cavity type, realizing diversified functions and miniaturized volume. Description of the Drawings

[0013] Figure 1 It is a structural schematic diagram of the utility model.

[0014] Figure 2 It is a three-dimensional schematic diagram of the utility model.

[0015] Figure 3 It is a circuit schematic diagram of the product of the utility model.

[0016] Description of the reference numerals: 1, housing; 2, input interface; 3, output interface; 4, current probe; 5, SMA connector; 6, capacitor one; 7, capacitor two; 8, discharge resistor; 9, mounting part. Detailed Embodiments

[0017] The following will describe the technical solutions in the embodiments of the utility model with reference to the drawings in the embodiments of the utility model:

[0018] As shown in the figure, a DC power grid conducted emission measurement device includes a housing 1. The housing 1 is in a cuboid structure. The left end of the housing 1 is an input interface 2, and the right end of the housing 1 is an output interface 3. The housing 1 contains four chambers, which are, from left to right, the input terminal wiring area, the power grid conducted measurement functional area, the DC power grid filtering functional area, and the output terminal wiring area. The joints between the four chambers use high-frequency insulating ceramic beads as insulating materials, which can withstand environments such as high voltage and high temperature. The input interface 2 is accommodated in the input terminal wiring area, and the output interface 3 is accommodated in the output terminal wiring area. The housing 1 is made of 304 stainless steel plate, and the structure is assembled and reinforced through technologies such as argon arc welding and machining. The surface of the housing 1 is electroplated with nickel and sprayed with polyurethane paint, with strong anti-corrosion ability. Both the input interface 2 and the output interface 3 adopt clamped stuffing box interfaces to fill the internal pores of the cable, so that the conductor and the insulating layer are effectively protected; the wiring interface is a copper current conductor rod made of hexagonal red copper rod, and the current conducting cross-sectional area of the copper rod is about 120mm 2 , and it can pass a current of 390A under normal circumstances, while the rated current of the device is 50A, leaving sufficient margin for current, with extremely small heat loss, and it is also convenient and reliable to install.

[0019] The power grid conducted measurement functional area includes a current probe 4 and an SMA connector 5. The current probe 4 is responsible for collecting interference signals in the DC power grid. The SMA connector 5 transmits the data collected by the current probe 4 to the upstream device. The power grid conducted measurement functional area has a DC power grid conducted emission information interface, and the current probe 4 and the SMA connector 5 are interconnected through a radio frequency coaxial cable. The SMA connector 5 is then connected to an external device to achieve signal transmission and reception. The SMA connector 5 is a small-sized coaxial connector with a threaded connection, which is convenient to connect. The structure of the current probe 4 is clamp-shaped and is wound with a material with a stable magnetic permeability to measure the induced current through the transfer impedance. The air gap, number of turns of winding, core thickness, core size, core material, etc. of the magnetic material are adjusted to make the transfer impedance curve of the current probe meet the usage requirements in the frequency band of 20Hz - 10MHz.

[0020] The DC grid filter functional area includes capacitor 1 6, capacitor 2 7 and discharge resistor 8. The size of capacitor 1 6 and capacitor 2 7 are both 20μF, and the parameter of discharge resistor 8 is 5W / 3MΩ. Capacitor 1 6 and capacitor 2 7 are both through-type capacitors. They are special capacitors made to reduce the influence of lead inductance and self-inductance, which greatly improves their self-resonant frequency. First, one electrode of the capacitor core is welded on the conductive shaft passing through the capacitor core, and the other electrode is connected to the grounded shell 1, so in fact this capacitor has only one thick wire and the lead inductance is extremely small. Secondly, the capacitor core adopts non-inductive winding. The winding method is that the two plates extend slightly in the opposite direction of the core width. The core after winding changes from a multi-turn coil to a single-turn coil. At the same time, the current direction also changes from the length direction of the plate in the general winding method to the width direction along the plate. The current path is greatly shortened and its own inductance is also greatly reduced.

[0021] The outer surface film of capacitor 16 and capacitor 27 is made of zinc-aluminum alloy thickened edge area vapor deposition, and a safe metallized polypropylene film with a built-in fuse. Because the film has a fuse inside, the self-container will automatically open the circuit in the case of overload, and the breakdown part is separated without affecting other parts. Therefore, capacitor 16 and capacitor 27 have self-healing ability and explosion-proof function, and have high safety performance.

[0022] Capacitor 1 6 and capacitor 2 7 are connected in series through a conductive copper connecting piece, which not only eliminates the influence of lead inductance, but also greatly improves the dielectric strength between electrodes. The rated voltage of capacitor 1 6 and capacitor 2 7 is 1200VDC. After capacitor 1 6 and capacitor 2 7 are connected in series, they can work in a circuit with a rated voltage of 2400VDC, and reliability is guaranteed.

[0023] Flame-retardant nylon hose is used to fill the space between capacitor 1 6 and the inner wall of housing 1, between capacitor 1 6 and capacitor 2 7, and between capacitor 2 7 and the inner wall of housing 1, which not only reduces weight, but also improves the product's ability to resist vibration and impact, and ensures the stability of capacitor 1 6 and capacitor 2 7. A plurality of mounting members 9 are provided around the outer surface of housing 1, and mounting members 9 are used to fix the device of the utility model to other equipment.

[0024] The above embodiments are only some embodiments of the utility model, not all embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

Claims

1. A DC grid conduction emission measurement device, comprising a housing (1), one end of the housing (1) being an input interface (2), the other end of the housing (1) being an output interface (3), the housing (1) comprising four chambers, which are, from left to right, an input terminal connection area, a grid conduction measurement functional area, a DC grid filtering functional area, and an output terminal connection area, characterized in that: The power grid conduction measurement functional area includes a current probe (4) and an SMA connector (5), and the current probe (4) and the SMA connector (5) are connected via a radio frequency coaxial cable; the DC power grid filtering functional area includes a capacitor 1 (6), a capacitor 2 (7) and a discharge resistor (8), and the capacitor 1 (6) and the capacitor 2 (7) are connected in series, and the discharge resistor (8) is connected in parallel with the capacitor 1 (6) and the capacitor 2 (7).

2. A DC power grid conducted emission measurement device as claimed in claim 1, characterized in that: High-frequency insulating ceramic beads are used as insulating materials at the connections between the four chambers.

3. A DC power grid conducted emission measurement device as claimed in claim 2, characterized in that: The current probe (4) is in a clamp-shaped structure and is wound with a material having a stable magnetic permeability.

4. A DC power grid conducted emission measurement device as claimed in claim 3, characterized in that: The SMA connector (5) is a threaded connector.

5. A DC power grid conducted emission measurement device as claimed in claim 4, characterized in that: Capacitor 1 (6) and capacitor 2 (7) are connected in series via a conductive copper connecting sheet.

6. A DC power grid conducted emission measurement device as claimed in claim 5, characterized in that: Capacitor 1 (6) and capacitor 2 (7) are both through-hole capacitors, and the size of capacitor 1 (6) and capacitor 2 (7) are both 20 μF.

7. A DC power grid conducted emission measurement device as claimed in claim 6, characterized in that: The parameters of the bleeder resistor (8) are 5W / 3MΩ.

8. A DC power grid conducted emission measurement device as claimed in claim 1, characterized in that: The shell (1) is made of 304 stainless steel plate, the surface of the shell (1) is nickel-plated and sprayed with a polyurethane paint layer, and the outer surface of the shell (1) is provided with a plurality of mounting parts (9).

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