JP2007225401A - Power line impedance stabilization network - Google Patents

Abstract

A power line impedance stabilization network capable of changing characteristics is provided.
A power line impedance stabilization network 1 includes two coaxial terminals 107 and 107 provided on a configuration surface 102a of a housing 102 and two modules 108 connected to the coaxial terminals 107 and 107. Prepare. The module 108 includes a coaxial terminal 108a fitted to the coaxial terminal 107, and a fixed impedance element 108b such as a fixed resistor connected to the coaxial terminal 108a.
[Selection] Figure 1

Description

  The present invention relates to a power line impedance stabilization network used for measuring a conducted disturbance wave conducted to a power line of a device.

  In recent years, inverter-controlled power supplies are used in many electrical and electronic devices, and inverter noise propagates through power lines.

  Since other devices are also connected to the power line through which conducted interference waves such as inverter noise propagate, international standardization organizations such as CISPR (International Special Committee on Radio Interference) have conducted conduction interference to prevent malfunction of the devices. An international standard that sets the value of the wave below the allowable value has been established, and each country carries out legal regulations and voluntary regulations based on this international standard.

  In addition, in the measurement method of conducted disturbances stipulated by this international standard, in order to obtain highly reproducible measurement results that do not depend on the measurement location, etc., the use of a power line impedance stabilization network and its characteristic common mode impedance and Specifies unbalance attenuation. The power supply line impedance stabilization network stabilizes the impedance of the power supply line, and is also referred to as an artificial power supply network (AMN) or a LISN (Line Impedance Stabilization Network).

  FIG. 7 shows a conventional power line impedance stabilization network 200 and a measurement method thereby.

  The power line impedance stabilization network 200 is connected to the casing 102 having the ground terminal 101, the single-phase two-wire outlet 103 provided on the constituent surface 102 a of the casing 102, and the outlet 103. Two power lines 104 extending outside the casing 102 through the inside, a low-pass filter 105 inserted into the power line 104 in the casing 102, and a portion of the power line 104 outside the casing 102 The plug 106 provided at the end of the power source 104 and two fixed impedance elements 104 a and 104 a connected between the power line 104 and the ground terminal 101 and having a constant impedance are provided.

In the measurement using the power line impedance stabilization network 200, the conducted disturbance wave is measured by a current probe or the like with the plug 106 connected to a commercial power source or the like and the power line of the device 20 is connected to the outlet 103. The
Kyoritsu Electronics Co., Ltd., Impedance stabilization network for PLC KNW-2241, [Search February 3, 2006], [online] Internet <URL: http: //www.kyoritsudenshi.co.jp/3products/3knw/ knw2241.htm> Techno Science Japan Co., Ltd. EMC Instrument LISN Pseudo Power Network, [Search February 3, 2006], [online] Internet <URL: http: //tsjcorp.co.jp/product/emc/LISN/emc_LISN.htm >

  By the way, recently, with the diversification of functions of equipment, many international standards have been established. Therefore, it is necessary to prepare a power line impedance stabilization circuit network having characteristics defined for each international standard.

  As a device having a plurality of functions, there is a set top box of a cable television system. Some of these set-top boxes have a function for transmitting and receiving video and audio signals of cable TV and a modem function for performing Internet access on the cable. In this case, two functions are supported. It is necessary to prepare a power line impedance stabilization network for each international standard.

  In addition, in a device that performs high-speed power line carrier communication that is currently being developed, a power line impedance stabilization circuit network that corresponds to two cases of performing the communication and not performing the communication is required.

  Even if the international standard is the same, it may be revised due to technological innovation or changes in social conditions. In such a case, the power line impedance stabilization network corresponding to the pre-revision international standard cannot be used. .

  As described above, since the characteristics of the power line impedance stabilization network cannot be changed, it is necessary to purchase a large number of power line impedance stabilization networks, or the purchased power line impedance stabilization network can be used. This will increase the cost of measuring conducted disturbances, which in turn will increase the price of the equipment.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a power line impedance stabilization circuit network capable of changing characteristics.

  In order to solve the above problems, the power line impedance stabilization circuit according to the present invention includes an impedance element or a variable impedance that is detachable between a power line introduced into the housing and a ground terminal provided in the housing. By providing the element, characteristics such as common mode impedance and unbalance attenuation characteristics can be changed.

  According to the power line impedance stabilization circuit network of the present invention, by providing a detachable impedance element or a variable impedance element between the power line introduced into the housing and the ground terminal provided in the housing, Characteristics such as mode impedance and unbalance attenuation characteristics can be changed. Thereby, it is not necessary to purchase a lot of power line impedance stabilization network, and can continue to use the purchased power line impedance stabilization network, thus reducing the cost of measuring conducted disturbance and reducing the equipment Can prevent price increases.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 shows a power line impedance stabilization network 1 according to a first embodiment.

  The power supply line impedance stabilization network 1 is connected to the casing 102 having the ground terminal 101, the single-phase two-wire outlet 103 provided on the constituent surface 102 a of the casing 102, and the outlet 103. Two power lines 104 extending outside the casing 102 through the inside, a low-pass filter 105 inserted into the power line 104 in the casing 102, and a portion of the power line 104 outside the casing 102 A plug 106 provided at the end of each of the terminals, two coaxial terminals 107 and 107 provided on the component surface 102a, and two modules 108 connected to the coaxial terminals 107 and 107. The module 108 includes a coaxial terminal 108a fitted to the coaxial terminal 107, and a fixed impedance element 108b such as a fixed resistor connected to the coaxial terminal 108a. The coaxial terminal 107 and the coaxial terminal 108a have a characteristic impedance of 50Ω, for example.

  The shaft metal of the coaxial terminal 107 is connected to the conductor of the power supply line 104, and the metal at the periphery is connected to the ground terminal 101. A fixed impedance element 108b is connected between the shaft portion metal of the coaxial terminal 108a and the surrounding metal portion.

  In the power line impedance stabilization network 1, a module 108 having fixed impedance elements 108b having different impedances is prepared.

  FIG. 2 shows an equivalent circuit of the power line impedance stabilization network 1.

  Z1 in FIG. 2 is the impedance of one fixed impedance element 108b, and Z2 is the impedance of the other fixed impedance element 108b.

  Equation (1) in FIG. 3 represents the common mode impedance CMZ [Ω] of the power line impedance stabilization network 1. Equation (2) in FIG. 3 represents the unbalanced attenuation LCL [dB] of the power line impedance stabilization network 1. In the formula (2), Z0 = Z1 + Z2.

  From these equations, it can be seen that if the impedance Z1 or Z2 is changed, the common mode impedance CMZ and the unbalance attenuation LCL change.

  Next, the measurement of the conducted disturbance using the power line impedance stabilization network 1 will be described.

  For example, when the power line impedance stabilization network 1 is used as a power line impedance stabilization network for high-speed power line carrier communication, the common mode impedance CMZ is 25Ω ± 20% and the unbalance attenuation LCL is 16 dB ± 3 dB. Is required. At this time, a module 108 having a fixed impedance element 108b having an impedance of 70Ω and a module 108 having a fixed impedance element 108b having an impedance of 35Ω are prepared, and these coaxial terminals 108a and 108a are fitted to the coaxial terminals 107 and 107. Combine.

  That is, Z1 and Z2 in FIG. 2 are set to 70Ω and 35Ω.

  FIG. 4A shows the result of measuring the frequency characteristics of the common mode impedance CMZ at this time. FIG. 4B shows the result of measuring the frequency characteristics of the unbalance attenuation LCL.

  Thus, the common mode impedance CMZ is 25Ω ± 20%, and the unbalance attenuation LCL is 16 dB ± 3 dB, which satisfies the requirement.

  Then, in the state where the plug 106 is connected to a commercial power source and the power source line of the device is connected to the outlet 103, the conducted interference wave is measured by a current probe or the like.

  Next, when conducting a conducted interference wave measurement after satisfying the requirements of different common mode impedance CMZ and unbalance attenuation LCL, another modules 108 and 108 having fixed impedance elements 108b having different impedances in advance are provided. Have it ready.

  Then, the used modules 108 and 108 are removed from the coaxial terminals 107 and 107, and the coaxial terminals 108 a and 108 a of other prepared modules 108 and 108 are fitted and attached to the coaxial terminals 107 and 107.

  That is, Z1 and Z2 in FIG. 2 are set to impedances different from the previous impedance. As a result, requirements for different common mode impedance CMZ and unbalanced attenuation LCL are satisfied, and the conducted interference wave is measured in that state.

  Therefore, by making the module 108 including the fixed impedance element 108b connected between the power line 104 and the ground terminal 101 removable, a plurality of modules 108 are prepared, and the impedance of the fixed impedance element 108b is made different. When connected to the coaxial terminal 107 and appropriately exchanged, as shown in FIGS. 5A and 5B, when Z1 and Z2 are changed, the common mode impedance CMZ and the unbalanced attenuation LCL are changed accordingly. Can be changed. Therefore, it is possible to measure conducted interference waves having different requirements.

  That is, since the fixed impedance element 108b between the power supply line 104 and the ground terminal 101 is made detachable, it is possible to measure the conducted interference wave having different requirements.

  In some cases, the measurement is performed as follows.

  For example, one module 108 having a fixed impedance element 108b having an impedance of 50Ω is prepared.

  Then, the coaxial terminal 108 a of this module 108 is fitted to one coaxial terminal 107. The other coaxial terminal 107 is connected to a measuring instrument (not shown) having a coaxial terminal fitted to it and having a characteristic impedance of 50 Ω at the input / output terminals. The measuring instrument conducts to one of the power lines 104. Measure the conducted disturbance.

  Next, the module 108 and the measuring device are removed from the coaxial terminals 107 and 107 and are exchanged so that they are connected to the coaxial terminals 107 and 107, and the measuring device in this state conducts to the other line of the power supply line 104. Measure the conducted disturbance.

  Therefore, when the module 108 is detachable, the coaxial terminal 107 and the coaxial terminal 108a fitted to the coaxial terminal 107 are used, so that not only the module 108 but also a measuring instrument having the coaxial terminal fitted to the coaxial terminal 107 can be attached and detached. It becomes possible.

  By the way, when measuring by switching the power line connecting the measuring instrument in this way, the power line impedance stabilization circuit network is provided with only one fixed impedance element 104a as shown in FIG. In addition to switching the power line connecting 104a, a switching switch is provided to switch the measuring terminal to which the measuring instrument is connected, so that measurement is performed while switching the switching switch while the measuring instrument is connected to the measuring terminal. However, in the first embodiment, since the module 108 including the fixed impedance element 108b having the same purpose as the fixed impedance element 104a is detachable, the changeover switch is not necessary.

[Second Embodiment]
FIG. 6 shows a power line impedance stabilization network 1A according to the second embodiment.

  The power supply line impedance stabilization network 1A has the same configuration as that of the power supply line impedance stabilization network 1.

  The difference is that the module 108 of the power supply line impedance stabilization network 1A includes not the fixed impedance element 108b but a variable impedance element 108c such as a variable resistor capable of changing its impedance.

  Next, the measurement of the conducted disturbance using the power line impedance stabilization network 1A will be described.

  When the power line impedance stabilization network 1A is used as a power line impedance stabilization network for high-speed power line carrier communication, the common mode impedance CMZ is 25Ω ± 20% and the unbalance attenuation LCL is 16 dB ± 3 dB. Therefore, two modules 108 are prepared, the impedance of one variable impedance element 108c is set to 70Ω, the impedance of the other variable impedance element 108c is set to 35Ω, and the coaxial terminals 108a, 108 a is fitted to the coaxial terminals 107 and 107.

  That is, Z1 and Z2 in FIG. 2 are set to 70Ω and 35Ω.

  As a result, as shown in FIGS. 4A and 4B, the common mode impedance CMZ is 25Ω ± 20% and the unbalance attenuation LCL is 16 dB ± 3 dB, which satisfies the requirement.

  Then, the plug 106 is connected to a commercial power source or the like, and the conducted interference wave is measured in a state where the power source line of the device is connected to the outlet 103.

  Next, in the case where conducted interference wave measurement is performed after satisfying the requirements of different common mode impedance CMZ and unbalanced attenuation LCL, for example, one or both modules with each module 108 attached. The setting of the impedance of the variable impedance element 108 c included in 108 is changed.

  That is, Z1 and Z2 in FIG. 2 are set to impedances different from the previous impedance. As a result, requirements for different common mode impedance CMZ and unbalanced attenuation LCL are satisfied, and the conducted interference wave is measured in that state.

  Therefore, by connecting the module 108 between the power supply line 104 and the ground terminal 101, if the impedance of the variable impedance element 108c is appropriately changed, as shown in FIGS. 5 (a) and 5 (b), Z1 and Z2 are changed. When changed, the common mode impedance CMZ and the unbalance attenuation LCL can be changed accordingly. Therefore, it is possible to measure conducted interference waves having different requirements.

  That is, since the variable impedance element 108c is connected between the power supply line 104 and the ground terminal 101, it is possible to measure the conducted interference wave having different requirements.

  Next, a description will be given of a case where measurement is performed by switching the power line connecting the measuring instrument.

  In this case, one module 108 is prepared in advance and, for example, its impedance is set to 50Ω.

  Then, the coaxial terminal 108 a of this module 108 is fitted to one coaxial terminal 107. The other coaxial terminal 107 is connected to a measuring device as described above, and the conducted measuring device conducts a conducted disturbance wave conducted to one of the power lines 104 with the measuring device.

  Next, the module 108 and the measuring device are removed from the coaxial terminals 107 and 107 and are exchanged so that they are connected to the coaxial terminals 107 and 107, and the measuring device in this state conducts to the other line of the power supply line 104. Measure the conducted disturbance.

  Therefore, by using the coaxial terminal 107 and the coaxial terminal 108a fitted to the coaxial terminal 107, not only the module 108 but also the measuring instrument having the coaxial terminal fitted to the coaxial terminal 107 can be attached and detached. Is no longer necessary.

  In the second embodiment, when the measurement for switching the power supply line connecting the measuring instrument is not performed, the variable impedance element 108c is not detachable, and the impedance setting may be simply changed.

  As described above, according to the power supply line impedance stabilization network according to the first and second embodiments, the power supply line introduced into the housing and the ground terminal provided in the housing can be attached and detached. By providing a simple impedance element or variable impedance element, characteristics such as common mode impedance and unbalance attenuation characteristics can be changed. Thereby, it is not necessary to purchase a lot of power line impedance stabilization network, and can continue to use the purchased power line impedance stabilization network, thus reducing the cost of measuring conducted disturbance and reducing the equipment Can prevent price increases.

1 is a perspective view of a power line impedance stabilization network 1A according to a first embodiment. FIG. 1 is a diagram showing an equivalent circuit of a power line impedance stabilization network 1. FIG. 3 is a diagram showing the common mode impedance CMZ [Ω] of the power supply line impedance stabilization network 1, and the formula (2) of FIG. It is a figure which shows balance attenuation amount LCL [dB]. FIG. 4A is a diagram showing the results of measuring the frequency characteristics of the common mode impedance CMZ, and FIG. 4B is a diagram showing the results of measuring the frequency characteristics of the unbalanced attenuation amount LCL. FIG. 5A is a diagram illustrating the value of the common mode impedance CMZ with respect to the impedances Z1 and Z2, and is a diagram illustrating the value of the unbalance attenuation LCL with respect to the impedances Z1 and Z2. It is a perspective view which shows 1 A of power supply line impedance stabilization networks based on 2nd Embodiment. It is a figure which shows the conventional power supply line impedance stabilization network 200 and the measuring method by it.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A ... Power line impedance stabilization network 20 ... Equipment 101 ... Ground terminal 102 ... Housing 104 ... Power line 104a ... Fixed impedance element 107, 108a ... Coaxial terminal 108 ... Module 108b ... Fixed impedance element 108c ... Variable impedance element

Claims (3)

A power line impedance stabilization network used to measure conducted disturbances conducted to equipment power lines,
A power line comprising a detachable impedance element or a variable impedance element between the power line introduced into the casing of the power line impedance stabilization circuit and a ground terminal provided in the casing. Impedance stabilization network.   2. The common mode impedance and / or the unbalance attenuation viewed from the device side change by changing the detachable impedance element or changing the impedance of the variable impedance element. Power line impedance stabilization network.   3. The power line according to claim 1, wherein a coaxial terminal is connected between the power line and the ground terminal, and a coaxial terminal fitted to the coaxial terminal is connected to the detachable impedance element. Impedance stabilization network.

Images