Power line conduction emission environment noise testing device

Abstract

The utility model discloses a power line conduction emission environment noise testing device. The device comprises a metal box, a passive load module and a fan heat dissipation module. The passive load module is arranged on the upper portion in the metal box, the fan heat dissipation module is arranged on the lower portion in the metal box, and the passive load module and the fan heat dissipation module are separated through a metal partition plate. The passive load module comprises a first connector, an air switch, a plurality of mechanical voltmeters and a plurality of RLC circuits. The fan heat dissipation module comprises a second connector, a switch, a filter and an electric fan. The load has resistance characteristics, capacitive reactance and inductive reactance effects, the impedance of the load can be adjusted, environmental noise under different load impedances can be detected, whether the environmental noise of a laboratory meets the standard test requirement or not can be effectively detected, the test mode is closer to the test mode of a tested product, the test result is more accurate, and the test efficiency is improved. And the interference of environmental noise on the test of the tested product can be eliminated.

Description

TECHNICAL FIELD

[0001] The utility model relates to the power transmission emission test field, concretely relates to a power line transmission emission environmental noise testing device. BACKGROUND

[0002] The power transmission emission test is a key test item in the electromagnetic compatibility test, which mainly tests the electromagnetic interference intensity of the electronic equipment outwardly transmitted through the power line when working. The test purpose of this item is to control the electromagnetic interference of the measured electronic equipment, improve the power quality, and reduce the electromagnetic interference of the measured electronic equipment to other equipment through the power line. However, in the test, the test often fails; in addition to the problem of the measured electronic equipment itself, another problem that often occurs is that the environmental noise does not meet the test requirements. Therefore, before testing, it is necessary to verify whether the environmental noise meets the standard requirements, which is a necessary action before product testing.

[0003] Nowadays, the environmental noise test is mainly verified by no-load or connecting a resistor, but these methods cannot effectively reflect the real electromagnetic environmental noise, and a passive load with nonlinear characteristics (active load will generate new electromagnetic noise, which will pollute the environmental noise, so active load cannot be used) needs to be designed, so that the electromagnetic environmental noise can be effectively tested.

[0004] No-load test cannot test the environmental noise floor, because the power supply is not closed-loop under no-load condition, which belongs to open-loop state, and there is no current, which cannot effectively reflect the electromagnetic environment when connecting the measured device;

[0005] Connecting a cement resistor for noise floor test also cannot reflect the environmental noise, because the cement resistor is a linear device, and the test product is a nonlinear device, which needs to have large inductive and capacitive characteristics, so as to have nonlinear characteristics, so as to effectively test the environmental noise. UTILITY MODEL CONTENTS

[0006] In order to overcome the defects of the prior art, the utility model provides a power line transmission emission environmental noise testing device.

[0007] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0008] The utility model provides a power line transmission emission environmental noise testing device, which comprises a metal box, a passive load module and a fan cooling module.

[0009] The passive load module is arranged above the inside of the metal box, and the fan heat dissipation module is arranged below the inside of the metal box, and the passive load module and the fan heat dissipation module are separated by a metal partition plate.

[0010] The passive load module comprises a first connector, an air switch, a plurality of mechanical voltmeters and a plurality of RLC circuits, the first connector is connected with the RLC circuits through the air switch, and the mechanical voltmeters are connected with the RLC circuits in parallel; the adjustable resistor and the inductor in the RLC circuit are connected in series, and the capacitor is connected with the adjustable resistor and the inductor in parallel.

[0011] The fan heat dissipation module comprises a second connector, a switch, a filter and an electric fan, and the second connector is connected to the electric fan in sequence through the switch and the filter.

[0012] As a preferred technical solution, three RLC circuits and two mechanical voltmeters are arranged, wherein the first mechanical voltmeter measures the voltage across one RLC circuit, and the second mechanical voltmeter measures the voltage across two parallel RLC circuits.

[0013] As a preferred technical solution, the first connector comprises four terminals L1, L2, L3 and N, wherein the N and L1 terminals are connected across the first mechanical voltmeter, and the L2 and L3 terminals are connected across the second mechanical voltmeter; the following connection modes are set during testing:

[0014] (1) When testing direct current power supply, the positive electrode is connected to the L1 terminal, and the negative electrode is connected to the N terminal.

[0015] (2) When testing single-phase alternating current power supply, the live wire is connected to the L1 terminal, and the neutral wire is connected to the N terminal.

[0016] (3) When testing three-phase alternating current power supply, the terminals are connected in the order of L1, L2, L3 and N.

[0017] As a preferred technical solution, the metal box is provided with an air slot in communication with the first connector and the second connector on the side surface.

[0018] As a preferred technical solution, the metal box is provided with an air slot on the side surface for displaying the measured value of the mechanical voltmeter and adjusting the resistance value of the adjustable resistor.

[0019] As a preferred technical solution, the metal box is provided with ventilation holes on the upper and lower surfaces.

[0020] As a preferred technical solution, the metal partition plate is provided with a slot at a position corresponding to the electric fan.

[0021] As a preferred technical scheme, the filter comprises parallelly connected ground capacitors CY1 and CY2, a parallel capacitor CX1, a parallel capacitor CX2, a series inductor L4, a parallel capacitor CX3, a parallel capacitor CX4, a series inductor L5, a parallel capacitor CX5 and a parallel capacitor CX6 arranged in sequence.

[0022] As a preferred technical scheme, the magnetic core material of the series inductor L4 and the series inductor L5 is nanocrystalline.

[0023] As a preferred technical scheme, the second connector is connected with an external power supply and used for supplying power for the electric fan.

[0024] Compared with the prior art, the power line conducted emission ambient noise testing device has the following advantages and beneficial effects:

[0025] (1) The power line conducted emission ambient noise testing device greatly improves the accuracy of power line conducted emission ambient noise testing of an electromagnetic compatibility laboratory, reduces the interference of ambient noise on product testing, and greatly improves the accuracy and testing efficiency of testing.

[0026] (2) The load of the power line conducted emission ambient noise testing device has resistance characteristics, capacitive reactance and inductive reactance effects, and the load impedance can be adjusted, and ambient noise under different load impedance can be detected, so that whether the ambient noise of the laboratory meets the standard testing requirements can be effectively detected, the testing mode is closer to product testing, the testing result is more accurate, and the interference of ambient noise on product testing can be eliminated.

[0027] (3) The power line conducted emission ambient noise testing device has the characteristics of simple structure, easy implementation and convenient operation. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a circuit principle schematic diagram of the power line conducted emission ambient noise testing device in the embodiment of the utility model;

[0029] Figure 2 is a box structure schematic diagram of the power line conducted emission ambient noise testing device in the embodiment of the utility model. DETAILED DESCRIPTION

[0030] In order to enable personnel in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0031] EMBODIMENT:

[0032] As Figure 1 shown in the power line conducted emission ambient noise test device provided by the embodiment 1, the device includes a metal box, a passive load module and a fan cooling module.

[0033] The passive load module is arranged above the inside of the metal box, and the fan cooling module is arranged below the inside of the metal box. The passive load module and the fan cooling module are separated by a metal partition plate, and the fan is located at an opening of the partition plate.

[0034] The passive load module includes a first connector, an air switch, a plurality of mechanical voltmeters and a plurality of RLC circuits. The first connector is connected to the RLC circuits through the air switch, and the mechanical voltmeters are connected in parallel to the RLC circuits. In the RLC circuit, an adjustable resistor is connected in series with an inductor, and a capacitor is connected in parallel to the adjustable resistor and the inductor.

[0035] The fan cooling module includes a second connector, a switch, a filter and an electric fan. The second connector is connected to the electric fan in sequence through the switch and the filter. The second connector is connected to an external power supply to supply power to the electric fan.

[0036] In a preferred embodiment, three RLC circuits and two mechanical voltmeters are provided. The first mechanical voltmeter measures the voltage across one RLC circuit, and the second mechanical voltmeter measures the voltage across two parallel RLC circuits. The first connector includes four terminals L1, L2, L3 and N. The N and L1 terminals are connected across the first mechanical voltmeter, and the L2 and L3 terminals are connected across the second mechanical voltmeter. The following connection modes are set during testing:

[0037] (1) When testing DC power supply, the positive electrode is connected to the L1 terminal, and the negative electrode is connected to the N terminal.

[0038] (2) When testing single-phase AC power supply, the live wire is connected to the L1 terminal, and the neutral wire is connected to the N terminal.

[0039] (3) When testing three-phase AC power supply, the terminals are connected in the order of L1, L2, L3 and N.

[0040] In a preferred embodiment, the metal box is provided with a hollow slot in communication with the first connector and the second connector.

[0041] In a preferred embodiment, the metal box is provided with a hollow slot for displaying the measurement value of the mechanical voltmeter and adjusting the resistance value of the adjustable resistor.

[0042] In a preferred embodiment, the metal box is provided with ventilation holes on the upper and lower surfaces of the box body. The lower surface is provided with an air inlet hole, and the upper surface is provided with an air outlet hole.

[0043] In a preferred embodiment, the filter comprises parallel ground capacitors CY1 and CY2, parallel capacitor CX1, parallel capacitor CX2, series inductor L4, parallel capacitor CX3, parallel capacitor CX4, series inductor L5, parallel capacitor CX5 and parallel capacitor CX6 arranged in sequence.

[0044] Further, the passive load module circuit component parameters are as follows:

[0045] Adjustable resistors R1-R3: the resistance adjustable range is 0-1000Ω, and the rated current is ≥10A (the greater the rated current is, the better).

[0046] Inductors L6-L8: the inductance is 1uH / 1KHz, and the rated current is ≥ the rated current of the adjustable resistor;

[0047] Capacitors C1-C3: the capacitance is 10uF, and X capacitor.

[0048] Further, the fan cooling module filter circuit component parameters are as follows:

[0049] L4 / L5: the inductance is 10mH / 100KHz, and the magnetic core material is nanocrystalline;

[0050] CX1 / CX3 / CX5: the capacitance is 1uF, and X capacitor.

[0051] CX2 / CX4 / CX6: the capacitance is 4.7uF, and X capacitor.

[0052] CY1 / CY2: the capacitance is 10nF, and Y capacitor.

[0053] Through research and experiments, the following requirements need to be paid attention to during passive load testing:

[0054] (1) Before testing, wiring should be performed according to the power supply mode,

[0055] (2) Before testing, the resistance value of the adjustable resistor should be calculated according to the size of the power supply voltage and the size of the tested power, and the resistance value of the adjustable resistor can be adjusted to the maximum value when not testing;

[0056] (3) The maximum test current of the load box should be set according to the rated current of the adjustable resistor (R1-R3) and the series inductor (L6-L8).

[0057] By using the design scheme as a test load, environmental noise can be effectively tested in the following test items in actual testing:

[0058] ;

[0059] The above embodiment is the preferred embodiment of the present application, but the embodiment of the present application is not limited by the above embodiment, and any change, modification, replacement, combination, simplification made without departing from the spirit and principle of the present application should be an equivalent replacement mode, and all are included in the protection scope of the present application.

Claims

1. A power line conducted emission ambient noise test apparatus, characterized by, The metal box, the passive load module and the fan heat dissipation module are included. The passive load module is arranged above the inside of the metal box, and the fan heat dissipation module is arranged below the inside of the metal box. The passive load module includes a first connector, an air switch, a plurality of mechanical voltmeters and a plurality of RLC circuits. The first connector is connected with the RLC circuits through the air switch, and the mechanical voltmeters are connected with the RLC circuits in parallel.

2. The power line conducted emission ambient noise test apparatus of claim 1, wherein, The adjustable resistor and the inductor in the RLC circuit are connected in series, and the capacitor is connected with the adjustable resistor and the inductor in parallel.

3. The power line conducted emission ambient noise test apparatus of claim 2, wherein, The fan heat dissipation module includes a second connector, a switch, a filter and an electric fan. Three RLC circuits and two mechanical voltmeters are arranged, wherein the first mechanical voltmeter measures the voltage between two ends of one RLC circuit, and the second mechanical voltmeter measures the voltage between two ends of two parallel RLC circuits. The first connector includes four terminals of L1, L2, L3 and N, wherein the N and L1 terminals are connected with two ends of the first mechanical voltmeter, and the L2 and L3 terminals are connected with two ends of the second mechanical voltmeter. The following connection modes are set during testing:

4. The power line conducted emission ambient noise test apparatus of claim 1, wherein, When testing direct current power supply, the positive electrode is connected with the L1 terminal, and the negative electrode is connected with the N terminal.

5. The power line conducted emission ambient noise test apparatus of claim 1, wherein, When testing single-phase alternating current power supply, the live wire is connected with the L1 terminal, and the zero line is connected with the N terminal.

6. The power line conducted emission ambient noise test apparatus of claim 1, wherein, When testing three-phase alternating current power supply, the L1, L2, L3 and N terminals are sequentially connected.

7. The power line conducted emission ambient noise test apparatus of claim 1, wherein, The metal box is provided with an air slot in communication with the first connector and the second connector.

8. The power line conducted emission ambient noise test apparatus of claim 1, wherein, The metal box is provided with an air slot for displaying the measured value of the mechanical voltmeter and adjusting the resistance value of the adjustable resistor.

9. The power line conducted emission ambient noise test apparatus of claim 8, wherein, The metal box is provided with ventilation holes on the upper and lower surfaces.

10. The power line conducted emission ambient noise test apparatus of claim 1, wherein, The metal partition plate is provided with a slot corresponding to the electric fan. The filter includes parallelly connected ground capacitors CY1 and CY2, parallelly connected capacitors CX1, CX2, CX3, CX4, CX5 and CX6, and series connected inductors L4 and L5. The magnetic cores of the series connected inductors L4 and L5 are nanocrystalline. The second connector is connected with an external power supply for supplying power to the electric fan.

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