JPH03238367A - Measurement of power source impedance for hot wire - Google Patents
Measurement of power source impedance for hot wireInfo
- Publication number
- JPH03238367A JPH03238367A JP3421390A JP3421390A JPH03238367A JP H03238367 A JPH03238367 A JP H03238367A JP 3421390 A JP3421390 A JP 3421390A JP 3421390 A JP3421390 A JP 3421390A JP H03238367 A JPH03238367 A JP H03238367A
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- JP
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- Prior art keywords
- power supply
- value
- voltage
- current
- load
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Links
- 238000005259 measurement Methods 0.000 title abstract description 32
- 238000000034 method Methods 0.000 claims abstract description 12
- 230000000630 rising effect Effects 0.000 claims description 5
- 230000002238 attenuated effect Effects 0.000 claims description 4
- 238000010586 diagram Methods 0.000 description 9
- 230000005284 excitation Effects 0.000 description 4
- 230000002159 abnormal effect Effects 0.000 description 3
- 230000002411 adverse Effects 0.000 description 3
- 230000010354 integration Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000001965 increasing effect Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 238000002847 impedance measurement Methods 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
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- Measurement Of Resistance Or Impedance (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は活線状態で電源インピーダンスを少なくとも測
定する活線の電源インピーダンスの測定方法に関するも
のである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for measuring the power supply impedance of a live line, which measures at least the power supply impedance in a live line state.
［従来の技術］
従来、電源インピーダンスを測定する方法としては被測
定電源に負荷を接続し、負荷を接続しなかった時との電
圧差、すなわち電圧降下と負荷電流とから電源インピー
ダンスを求める方法があった。また家庭や、工場等で伝
送信号の減衰量の計算、短絡電流の予測などを行うため
に線路の時定数を測定する方法としては従来専用の計測
器を用いて電源をオフして測定する方法があった。[Prior Art] Conventionally, the method for measuring power supply impedance is to connect a load to the power supply under test and calculate the power supply impedance from the voltage difference from when no load is connected, that is, the voltage drop and load current. there were. In addition, the conventional method of measuring the time constant of a line in order to calculate the amount of attenuation of a transmission signal, predict short-circuit current, etc. at home or in a factory is to turn off the power and measure using a dedicated measuring instrument. was there.
［発明が解決しようとする課題］
ところが上記従来の電源インピーダンスの測定方法では
十分な測定精°度を得るには電圧降下のためには電圧降
下比を少なくとも１０％以上とる必要がある。このため
電圧降下によって接続機器の動作異常が起きる恐れがあ
る。また例えば電源インピーダンスが０．１Ωで、電源
電圧が１００Ｖの場合、１００Ａの電流を流す必要があ
るため、大容量の負荷装置を必要とし、しかも大電流が
流れるため配電盤のブレーカが動作して停電する恐れが
ある等の弊害を伴うので、精度よく測定できないという
問題があった。[Problems to be Solved by the Invention] However, in the conventional power source impedance measurement method described above, in order to obtain sufficient measurement accuracy, it is necessary to have a voltage drop ratio of at least 10% or more for voltage drop. Therefore, the voltage drop may cause abnormal operation of the connected equipment. For example, if the power supply impedance is 0.1Ω and the power supply voltage is 100V, it is necessary to flow a current of 100A, which requires a large-capacity load device, and because the large current flows, the circuit breaker on the distribution board will trip, resulting in a power outage. There was a problem in that accurate measurement could not be carried out because of the disadvantages such as the possibility of
また時定数を求める従来の方法では活線状態で測定でき
ないため、稼働している工場では不適切であった。Furthermore, conventional methods for determining time constants cannot be measured under live wire conditions, making them unsuitable for operating factories.
本発明は叙述の問題点に鑑みて為されたもので、請求項
一１記載の発明の目的とするところは、活線状態とした
ままで電源インピーダンスを高い精度で測定することが
でき、しかも大容量の負荷装置を必要とせず、また配電
盤のブレーカが動作して停電する恐れが無く、更に他の
接続機器の動作異常を起こすことが無い活線の電源のイ
ンピーダンスの測定方法を提供するにある。The present invention has been made in view of the problems described above, and an object of the invention as set forth in claim 11 is to be able to measure power supply impedance with high accuracy while the line is in a live state, and To provide a method for measuring the impedance of a live power source that does not require a large-capacity load device, does not cause a power outage due to the operation of a breaker in a distribution board, and does not cause abnormal operation of other connected equipment. be.
また請求項２記載の発明の目的とするところは、活線状
態としたままで電源インピーダンスを高い精度で測定す
ることができ、しかも大容量の負荷装置を必要とせず、
また配電盤のブレーカが動作して停電する恐れが無く、
更に他の接続機器の動作異常を起こすこと無く精度よく
測定でき、同時に活線状態としたままで時定数を測定す
ることができる活線の電源のインピーダンスの測定方法
を提供するにある。Further, the object of the invention as set forth in claim 2 is to be able to measure the power source impedance with high accuracy while the line is in a live state, and without requiring a large capacity load device.
In addition, there is no risk of a power outage due to tripping of the circuit breaker on the power distribution board.
Furthermore, it is an object of the present invention to provide a method for measuring the impedance of a live power source, which can measure the impedance of a live power source with high accuracy without causing abnormal operation of other connected equipment, and at the same time can measure the time constant while keeping the live line in a live state.
［課題を解決するための手段］
上述の目的を達成するために、請求項１記載の発明は被
測定電源の両端に電流測定手段とスイッチ要素とを介し
て負荷抵抗を接続し、上記スイッチ要素を電源位相に同
期して１サイクルおきに電流零点で投入して短時間後に
開放するとともに、この投入、開放によって得られる被
測定電源両端の無負荷時電圧のピークホールド値と、負
荷時電圧のピークホールド値との差電圧を多数回積分し
、該積分値を電圧降下値に変換して該電圧降下値を上記
電流測定手段で得た負荷電流で除することにより電源イ
ンピーダンスを測定することを特徴とする。[Means for Solving the Problem] In order to achieve the above-mentioned object, the invention according to claim 1 connects a load resistor to both ends of a power supply to be measured via a current measuring means and a switch element, and is turned on at the current zero point every other cycle in synchronization with the power supply phase, and then opened after a short time, and the peak hold value of the voltage at no load across both ends of the power supply under test obtained by this turning on and opening, and the voltage at load The power supply impedance is measured by integrating the voltage difference from the peak hold value many times, converting the integrated value into a voltage drop value, and dividing the voltage drop value by the load current obtained by the current measuring means. Features.
また請求項２記載の発明は被測定電源の両端に分流器と
スイッチ要素とを介して負荷抵抗を接続し、上記スイッ
チ要素を短時間開じてスイッチ要素の閉じた時点から始
まる電流の立ち上がり勾配期間の所定時点の電流値を読
み取り、この読み取った電流値より電源の抵抗／電源の
インダクタンスを求め、その後重畳直流分が無視出来る
値に減衰した時点で取り込んだ電流値と、電圧降下値と
より電源インピーダンスを求めることを特徴とする。In addition, the invention according to claim 2 connects a load resistor to both ends of the power supply to be measured via a shunt and a switch element, and opens the switch element for a short time to generate a rising slope of the current that starts from the time when the switch element is closed. Read the current value at a predetermined point in time, calculate the resistance of the power supply/inductance of the power supply from this read current value, and then calculate the current value taken at the time when the superimposed DC component has attenuated to a negligible value and the voltage drop value. It is characterized by finding the power supply impedance.
［作用］
而して請求項１記載の発明によれば、スイッチ要素を電
源位相に同期して１サイクルおきに電流零点で投入して
短時間後に開放することにより、被測定電源に負荷抵抗
を接続した状態と、接続しない無負荷状態とを交互に設
定し、負荷状態の電圧と、無負荷状態の電圧とを対応す
るピークホールド回路により波形変換してこの変換した
電圧の差電圧を求める。つまり１サイクル毎に通電時と
非通電時との電圧差を求める。更にこの差電圧を積分回
路にて多数回積分する。[Function] According to the invention described in claim 1, the load resistance is applied to the power source to be measured by turning on the switch element at the current zero point every other cycle in synchronization with the power supply phase and opening it after a short time. A connected state and a no-load state without connection are set alternately, and the waveforms of the voltage in the loaded state and the voltage in the no-load state are converted by the corresponding peak hold circuits, and the difference voltage between the converted voltages is determined. In other words, the voltage difference between the energized state and the non-energized state is determined for each cycle. Furthermore, this differential voltage is integrated many times by an integrating circuit.
この積分回路で得られる積分値を前取て作成した換算式
より電圧降下値に変換し、別途に設けている電流測定手
段により測定した負荷電流で除することにより電源イン
ピーダンスを求めることができるのである。The power supply impedance can be determined by converting the integral value obtained by this integrating circuit into a voltage drop value using a conversion formula prepared in advance and dividing it by the load current measured by a separately provided current measuring means. be.
ここで積分回路にて多数回差電圧を積分することにより
、負荷時電圧と無負荷時電圧との差電圧が小さくても大
きな電圧値が得られて電源インピーダンスを容易に測定
することができ、また毎サイクルごとに無負荷時電圧ピ
ークホールド電圧と負荷時電圧のピークホールド電圧と
を比較することにより、瞬間的な電源電圧の変動の影響
を受けないのである。また電圧降下が短時間であるため
、接続機器の動作に悪影響を与えず、配電盤のブレーカ
も遮断することもなく、更に大容量の負荷装置を必要と
せず、測定時の電力損失も激減できる。By integrating the voltage difference multiple times in an integrating circuit, a large voltage value can be obtained even if the voltage difference between the load voltage and the no-load voltage is small, and the power source impedance can be easily measured. In addition, by comparing the no-load voltage peak hold voltage and the load voltage peak hold voltage every cycle, it is not affected by instantaneous fluctuations in the power supply voltage. In addition, since the voltage drop is short-term, it does not adversely affect the operation of connected equipment, does not trip the circuit breaker on the power distribution board, does not require a large-capacity load device, and can dramatically reduce power loss during measurement.
しかもスイッチ要素が電流零点で閉じるから直流分が重
畳して測定誤差を生じるような事もなく高い精度で測定
できる。Furthermore, since the switch element closes at the current zero point, there is no possibility of measurement errors caused by superimposition of direct current components, allowing for highly accurate measurements.
また請求項２記載の発明によれば、電源を短時間投入し
た活線状態で、電流の立ち上がり勾配における所定時点
の電流値から電源の抵抗／電源のインダクタンスを求め
て時定数を測定することができる。この場合スイッチ要
素の投入期間は極めて短時間であるため、上記電盤のブ
レーカを遮断することもなく、更に大容量の負荷装置を
必要とせず、測定時の電力損失も激減できる。また同時
に重畳直流分が無視できる値に減衰した時点に取り込ん
だ電流の値と、電圧降下値とより電源インピーダンスを
求めるため、電圧降下比を大きくすることができて、高
い精度で電源インピーダンスの測定ができる。According to the second aspect of the invention, the time constant can be measured by determining the resistance of the power source/inductance of the power source from the current value at a predetermined point in the rising slope of the current in a live line state where the power source is turned on for a short time. can. In this case, the closing period of the switch element is extremely short, so there is no need to shut off the breaker of the electrical panel, and there is no need for a large-capacity load device, and power loss during measurement can be drastically reduced. At the same time, the power source impedance is calculated from the voltage drop value and the current value taken in at the time when the superimposed DC component has attenuated to a negligible value, making it possible to increase the voltage drop ratio and measure power source impedance with high accuracy. Can be done.
［実施例］ 以下本発明を実施例により説明する。[Example] The present invention will be explained below with reference to Examples.
Ｘ胤廻ユ
第１図は請求項１記載の発明に対応する方法の一実施例
の回路構成例を示しており、被測定電源Ｅとその電源イ
ンピーダンスＺとの直列回路の両端に相当する被測定電
源端ａ、ａ′間に電流測定手段である電流計Ａと、測定
回路１で制御されるスイッチ要素たるリレーＲＹ、のリ
レー接点に１を介して負荷抵抗Ｒ，を接続し、測定回路
１の測定端子を上記電流計Ａを介して被測定電源端ａ、
ａ′間に接続している。Figure 1 shows an example of the circuit configuration of an embodiment of the method according to the invention as claimed in claim 1. A load resistor R is connected between the measurement power supply terminals a and a' to the relay contact of the ammeter A, which is a current measurement means, and the relay RY, which is a switch element controlled by the measurement circuit 1, through the measurement circuit 1. 1 measurement terminal is connected to the measured power supply terminal a through the ammeter A,
It is connected between a'.
測定回路１は第２図に示すように電源電圧Ｖを入力して
その電源電圧位相に同期して各種の信号を発生する制御
回路２を備え、この制御回路２は直流分が重畳して測定
誤差を生じないように上記リレー接点に１を電流零点で
投入し、はぼ１／２サイクル後に開放するように上記リ
レーＲＹ、の励磁コイルに流す励磁電流を第３図（ｂ）
で示す制御信号Ｑ、で制御し、同時に別のリレーＲＹ２
の励磁コイルに流す励磁電流を制御し、そのリレー接点
に２により無負荷時電圧をピークホールド回路３ａに、
負荷時電圧をピークホールド回路３ｂに切り換え接続す
る。また積分回路５の積分開始、積分停止の信号を作成
する。As shown in Fig. 2, the measurement circuit 1 includes a control circuit 2 that inputs a power supply voltage V and generates various signals in synchronization with the phase of the power supply voltage. 1 is applied to the relay contact at the current zero point to avoid errors, and the excitation current is applied to the excitation coil of the relay RY so as to open after approximately 1/2 cycle as shown in Fig. 3(b).
is controlled by a control signal Q, denoted by , and simultaneously another relay RY2.
The excitation current flowing through the excitation coil is controlled, and the no-load voltage is sent to the peak hold circuit 3a through the relay contact 2.
The load voltage is switched and connected to the peak hold circuit 3b. It also generates signals for the integration circuit 5 to start and stop integration.
ピークホールド回路３ａ、３ｂは第４図に示すような具
体回路から構成され、第３図に示すように夫々入力する
無負荷時電圧ＶＡ、負荷時電圧Ｖｌｌを破線で示す電圧
ＶＩ、Ｖ２に変換するための回路であり、これらのピー
クホールド回路２．３の出力電圧Ｖ、、Ｖ２は差動増幅
回路４に入力されてその差電圧Ｖ３が求められ、差電圧
Ｖ、は積分回路５に入力される。The peak hold circuits 3a and 3b are constructed from concrete circuits as shown in FIG. 4, and convert the input no-load voltage VA and load voltage Vll, respectively, into voltages VI and V2 shown by broken lines as shown in FIG. The output voltages V, , V2 of these peak hold circuits 2.3 are input to the differential amplifier circuit 4 to obtain the differential voltage V3, and the differential voltage V, is input to the integrating circuit 5. be done.
しかして本実施例によれば、リレー接点に、を電源位相
に同期させて開閉を繰返して、負荷抵抗Ｒ５を接続した
状態と、非接続状態とを交互に設定し、測定回路１に取
込む電圧を負荷状態の電圧■、と、無負荷状態の電圧Ｖ
、とし、夫々の電圧を対応するピークホールド回路３ａ
、３ｂに入力して波形変換し、この変換された電圧Ｖ、
、Ｖ２の差電圧Ｖ３を差動増幅回路４で求める。つまり
１サイクル毎に通電時と非通電時との電圧差を求める。According to this embodiment, the relay contacts are repeatedly opened and closed in synchronization with the power supply phase, and the load resistor R5 is alternately set to a connected state and a disconnected state, and the relay contacts are input into the measurement circuit 1. The voltage in the loaded state is the voltage ■, and the voltage in the no-load state is V.
, and a peak hold circuit 3a corresponding to each voltage.
, 3b and converts the waveform, and this converted voltage V,
, V2 is determined by the differential amplifier circuit 4. In other words, the voltage difference between the energized state and the non-energized state is determined for each cycle.
更にこの電圧Ｖ、を制御回路２の制御の下で積分回路５
にて６０〜１２０サイクル［１〜２秒間コ積分する。Furthermore, this voltage V is applied to the integrating circuit 5 under the control of the control circuit 2.
60-120 cycles [co-integrate for 1-2 seconds.
この積分回路５で得られる積分値Ｖ４を前取て作成した
換算式より電圧降下値ΔＶに変換し、別途に設けている
電流計Ａにより測定した負荷電流で除することにより電
源インピーダンスＺを求めることができるのである。The integrated value V4 obtained by the integrating circuit 5 is converted into a voltage drop value ΔV using a conversion formula prepared in advance, and the power supply impedance Z is obtained by dividing the voltage drop value ΔV by the load current measured by a separately provided ammeter A. It is possible.
このように本実施例１では積分回路５にて負荷時電圧の
ピークホールド電圧ＶＡと無負荷時のピークホールドＶ
、との差電圧Ｖ、を多数回積分することにより、差電圧
Ｖ、が小さくても大きな電圧値Ｖ、が得られて電源イン
ピーダンス２を容易に測定することができ、また毎サイ
クルごとに比較することにより、瞬間的な電源電圧の変
動の影響を受けない。尚電圧降下比を１０％以上にとれ
ば０．５％精度の電流計Ａを使用することにより５％の
精度で電源インピーダンスＺを求めることができる。In this way, in the first embodiment, the integration circuit 5 calculates the peak hold voltage VA of the load voltage and the peak hold voltage V of the no-load voltage.
, by integrating the difference voltage V, many times, a large voltage value V can be obtained even if the difference voltage V, is small. By doing so, it is not affected by instantaneous power supply voltage fluctuations. If the voltage drop ratio is set to 10% or more, the power supply impedance Z can be determined with an accuracy of 5% by using the ammeter A with an accuracy of 0.5%.
Ｘ隨透ユ
上記実施例１は電源インピーダンスＺのみを求める方法
であったが、本実施例２は線路の時定数をも同時に測定
できる請求項２記載の発明の方法に対応する実施例であ
る。Although the first embodiment described above was a method for determining only the power supply impedance Z, this second embodiment is an embodiment corresponding to the method of the invention as claimed in claim 2, in which the time constant of the line can also be measured at the same time. .
第５図は本実施例２の回路構成を示しており、被測定電
源端子ａ、ａ’に負荷抵抗Ｒ，、電流開閉用のリレー接
点に１、分流器６の直列回路を接続するとともに、２チ
ヤンネルのデジタルメモリスコープ７に分流器６に被測
定電源端子ａ、ａ′間の電源電圧■と、分流器６の出力
とを入力する。FIG. 5 shows the circuit configuration of the second embodiment, in which a series circuit of a load resistor R, a current switching relay contact 1, and a shunt 6 are connected to the power supply terminals a and a' to be measured. The power supply voltage (2) between the power supply terminals a and a' to be measured and the output of the shunt 6 are input to the two-channel digital memory scope 7 .
リレー接点に、は電源Ｅの電圧Ｖが最大値を過ぎた時点
（ピーク値時刻ｔ、より１〜２ｍｓ経過後）で閉じられ
、閉じられてから１〜２ｍｓ経過後開放されるように制
御手段（図示せず）で制御されるリレー（図示せず）の
リレー接点であり、デジタルメモリスコープ７には第６
図に示す電圧Ｖ・電流■波形が入力することになる。The relay contact is closed when the voltage V of the power source E exceeds the maximum value (1 to 2 ms after the peak value time t), and is controlled to be opened after 1 to 2 ms has passed after being closed. This is a relay contact of a relay (not shown) controlled by a relay (not shown), and the digital memory scope 7 has a sixth
The voltage V and current ■ waveforms shown in the figure will be input.
ここでリレー接点に、の投入後の電流は次式で表される
。Here, the current after the relay contact is turned on is expressed by the following equation.
１（ｔ）＝Ｉ鵬・５ｉｎ（１２０ｒｔ＋θ−ψ）＋ Ｉ
Ｐｓｉｎ（ψ−θ）ｅ−１ｆＲ６＋ｌｌ、 Ｉｔｌ／Ｌ
Ｏ，、、■θ：投入角 Ｌｏ：電源Ｅのインダクタンス
Ｒ０：電源Ｅの抵抗
電源配線ではインダクタンスＬ。はＯ，０ＯＩＨ以下、
抵抗Ｒ１は１００程度であるから１２０πＬ、＜Ｒ，と
なり、ψ＃０と見做せる。1(t)=Ipeng・5in(120rt+θ−ψ)+I
Psin(ψ-θ)e-1fR6+ll, Itl/L
O, , ■θ: Closing angle Lo: Inductance of power supply E R0: Resistance of power supply E Inductance L in power supply wiring. is less than O,0OIH,
Since the resistance R1 is about 100, 120πL,<R, and can be regarded as ψ#0.
またＴ２＜０．０００１なので０式は次のように簡略化
できる。Also, since T2<0.0001, equation 0 can be simplified as follows.
１（ｔ）＝ ｌｍ５ｉｎ（θ）（１ｅ−１１’ Ｏ”
ｌ ｔＩ八へ）、、、■Ｉ
従って第６図より投入時刻ｔ０から始まる電流立ち上が
り期間のＴ１経過時点、Ｔ２経過時点に於ける電流値Ｉ
ｔ、Ｉ２を読み取れば、負荷抵抗Ｒの値が既知であるの
で■式よりＲ８／Ｌ、を求めることができる。1(t)=lm5in(θ)(1e-11'O"
l tI8),,,■I Accordingly, from FIG. 6, the current value I at the elapsed time of T1 and the time of elapse of T2 of the current rise period starting from the input time t0.
By reading t and I2, since the value of the load resistance R is known, R8/L can be determined from the equation (2).
通を後重畳直流分が無視できる値に減衰した時刻ｔｚ（
１ｍｓで１１５０以下〉における電流値工、と、この時
の図より求めた電圧降下値ΔＶより次の式から電源イン
ピーダンスＺを求めることができる。The time tz (
The power supply impedance Z can be determined from the following equation using the current value ΔV determined from the diagram at this time and the current value ΔV at 1150 or less for 1 ms.
コノ場合計算はやや繁雑になるが、電圧降下値ΔＶを他
の既知の電源電圧Ｖの値より求めるとより精度良く求め
られる。In this case, the calculation becomes a little complicated, but if the voltage drop value ΔV is determined from other known values of the power supply voltage V, it can be determined more accurately.
Ｚ＝ΔＶＡＴ ・・・■同位相
差を無視しているが重大な誤差を生じない。Z=ΔVAT...■ Although the same phase difference is ignored, no serious error occurs.
またリレー接点に、を電圧ピーク付近で投入すると、通
ＩＣ電流が大きくなって測定精度を良くすることができ
るが、電流遮断が困難なため通電時間を２ｍｓ以内に納
めることが困難である。逆に電流零点に近い時刻で投入
すると電流遮断は容易だが、通電電流の波高値が低下し
測定精度が悪くなる。In addition, if the relay contact is turned on near the voltage peak, the passing IC current increases and the measurement accuracy can be improved, but it is difficult to cut off the current and it is difficult to keep the current passing time within 2 ms. On the other hand, if the current is turned on at a time close to the current zero point, it is easy to interrupt the current, but the peak value of the applied current decreases and measurement accuracy deteriorates.
以上のようにして本実施例２ではごく短時間（１ｍｓ〜
２ｍ５）だけ通電して電圧Ｖ・電流工波形より電源イン
ピーダンス測定及び線路の時定数を行うものであるため
、ごく短時間の電圧降下が生じるだけ、接続されている
機器の動作異常を起こさない、また短時間の過電流では
配電盤のブレーカが動作しない。更に負荷容量を１／２
００〜１１５００に低下できて小さくでき、測定時の電
力損失も激減できる。また電圧降下比を２０〜３０％に
とることができて、測定精度を上げられる。更に同時に
電流波形の立ち上がり勾配より線路の時定数を求めるこ
とができるため、電源インピーダンスの測定の回路を共
通とすることができる。As described above, in this embodiment 2, a very short time (1 ms ~
Since the power source impedance is measured and the line time constant is measured using the voltage V and current waveforms by applying current to only 2m5), only a short voltage drop occurs and the connected equipment does not malfunction. In addition, the circuit breaker on the power distribution board does not operate due to short-term overcurrent. Furthermore, the load capacity is halved
00 to 11,500 and can be made small, and the power loss during measurement can be drastically reduced. Furthermore, the voltage drop ratio can be set to 20 to 30%, increasing measurement accuracy. Furthermore, since the time constant of the line can be determined from the rising slope of the current waveform at the same time, it is possible to use a common circuit for measuring power source impedance.
上記実施例１は電源インピーダンスのみの測定量するも
のでり、実施例２は線路時定数も同時に測定できるもの
であったが、。In the first embodiment, only the power supply impedance was measured, and in the second embodiment, the line time constant could also be measured at the same time.
線路の時定数を活線のままで測定できる測定方法として
は第７図に示す回路構成による方法がある。As a measurement method that allows the time constant of a line to be measured while the line remains live, there is a method using a circuit configuration shown in FIG.
この第７図に示す回路では被測定電源端ａ、ａ′にリレ
ー接点に４と、負荷抵抗Ｒ１と、分流器６との直列回路
を接続し、分流器６出力をデジタルメモリスコープ７に
入力するようにしたもので、被測定電源Ｅの電圧波高値
付近でリレー接点に４を閉じて、電力損失や他の機器へ
の悪影響を避ける為に開放する。In the circuit shown in FIG. 7, a series circuit consisting of relay contact 4, load resistor R1, and shunt 6 is connected to the power supply terminals a and a' to be measured, and the output of shunt 6 is input to digital memory scope 7. The relay contact 4 is closed near the voltage peak value of the power supply to be measured E, and opened to avoid power loss and adverse effects on other equipment.
この時の電圧Ｖ・電流Ｉ波形は第８図に示すようになる
。ここでリレー接点４の投入、開放の制御は実施例２と
同様に行い、そのリレー接点に４の投入時の電流は上記
実施例２の場合に於けるの弐〜■式で示すことができる
。The voltage V and current I waveforms at this time are as shown in FIG. Here, the closing and opening of the relay contact 4 is controlled in the same manner as in the second embodiment, and the current when the relay contact 4 is closed can be expressed by the equations 2 to 2 in the case of the second embodiment. .
ここで１２０πＬ、＜Ｒ，，１＝０とすると、上記■式
は次のように訂正する。Here, if 120πL,<R,, 1=0, the above equation (2) is corrected as follows.
１（ｔ）＝ ｌｍ５ｉｎ（θ）＋１ｍ５ｉｎ（−〇）ｅ
−１１Ｉ Ｏ＋１１１１ ｔ Ｉ ／ Ｌ□・・・■
′
更に投入角θを９０°に選ぶと次のようになる。1(t)=lm5in(θ)+1m5in(-〇)e
-11I O+1111 t I/L□・・・■
' Furthermore, if the input angle θ is chosen to be 90°, the result is as follows.
１（ｔ）＝Ｉｍ（１−ｅ−”””Ｉ ｌｔｌ／ＬＯ）
、、、■″従って第６図の波形により時刻ｊ
ｌ＋ ｔ２に於けるｔ流値１．、Ｉ２を読み取れば容易
にＲｏ／Ｌｏを求めることができる。接点投入時の角度
が９０’付近でなくても■′式より求めることができる
が９０”付近ではＩ（ｔ）が最大となって、測定精度が
良くなる。1(t)=Im(1-e-"""I ltl/LO)
,,,■''Therefore, according to the waveform in Fig. 6, time j
l+ t flow value at t2 1. , I2, Ro/Lo can be easily determined. Even if the angle at the time of closing the contact is not around 90', it can be determined from the equation (2), but when the angle is around 90'', I(t) becomes maximum and the measurement accuracy improves.
また通電時間はＯ，１ｍｓ程度以下で十分である。Further, it is sufficient for the current application time to be approximately 0.1 ms or less.
更に測定精度を上げるには負荷抵抗Ｒ３は無誘導のもの
を用いるか、前取てそのインダクタンス分を測定してお
き、■−式で求めた値から差し引けば良い、同様に分流
器６もインダクタンス分の少ないものが必要である。To further improve the measurement accuracy, use a non-inductive load resistor R3, or measure the inductance in advance, and subtract it from the value calculated using the formula.Similarly, for the shunt 6, A device with low inductance is required.
〔発明の効果コ
請求項１記載の発明は、被測定電源の両端に電流測定手
段とスイッチ要素とを介して負荷抵抗を接続し、上記ス
イッチ要素を電源位相に同期して１サイクルおきに電流
零点で投入して短時間後に開放するとともに、この投入
、開放によって得られる被測定電源両端の無負荷時電圧
のピークホールド値と、負荷時電圧のピークホールド値
との差電圧を多数回積分し、該積分値を電圧降下値に変
換して該電圧降下値を上記電流測定手段で得た負荷電流
で除することにより電源インピーダンスを測定するので
、無負荷時電圧と負荷時電圧との差電圧が小さくても大
きな電圧値が得られて電源インピーダンスを容易に測定
することができ、また毎サイクルごとに無負荷時電圧と
負荷時電圧とを比較することにより、瞬間的な電源電圧
の変動の影響を受けず、また通電による電圧降下が短時
間であるため、接続機器の動作に悪影響を与えず、また
配電盤のブレーカも遮断することがなく、更に通電時間
が短時間であるから大容量の負荷装置を必要とせず、測
定時の電力損失も激減でき、しかもスイッチ要素が電流
零点で閉じるから直流分が重畳して測定誤差を生じるよ
うなこともなく高い精度で測定できるという効果がある
。[Effects of the Invention] The invention described in claim 1 connects a load resistor to both ends of the power supply to be measured via a current measuring means and a switch element, and connects the switch element to the power supply phase to measure the current every other cycle. It is turned on at the zero point and then opened after a short time, and the difference voltage between the peak hold value of the no-load voltage across the power supply under test and the peak hold value of the voltage on load obtained by turning on and opening the power supply is integrated many times. , the power supply impedance is measured by converting the integral value into a voltage drop value and dividing the voltage drop value by the load current obtained by the current measuring means, so the difference voltage between the no-load voltage and the loaded voltage Even if the voltage is small, a large voltage value can be obtained, making it easy to measure the power supply impedance.Also, by comparing the no-load voltage and the loaded voltage every cycle, it is possible to detect instantaneous fluctuations in the power supply voltage. Since it is not affected by electricity and the voltage drop due to energization is short, it does not adversely affect the operation of connected equipment and does not trip the circuit breaker on the distribution board.Furthermore, because the energization time is short, large capacity There is no need for a load device, power loss during measurement can be drastically reduced, and since the switch element closes at the current zero point, there is no possibility of measurement errors caused by superimposition of DC components, allowing for highly accurate measurements.
また請求項２記載の発明は被測定電源の両端に分流器と
スイッチ要素とを介して負荷抵抗を接続し、上記スイッ
チ要素を短時間開じてスイッチ要素の閉じた時点から始
まる電流の立ち上がり勾配期間の所定時点の電流値を読
み取り、この読み取った電流値より電源の抵抗／電源の
インダクタンスを求めから、線路の時定数を活線状態で
測定することができ、しかもこの場合スイッチ要素の投
入期間は極めて短時間であるため、配電盤のブレーカも
遮断することがなく、更に大容量の負荷装置を必要とせ
ず、測定時の電力損失も激減でき、また同時に重畳直流
分が無視できるる値に減衰した時点に取り込んだ電流値
と、電圧降下値とより電源インピーダンスを求めるため
、電圧降下比を大きくすることができて、高い精度で測
定ができ、また時定数測定と同じ回路を使用することに
より、測定回路のコストも安価で且つ簡単であるという
効果がある。In addition, the invention according to claim 2 connects a load resistor to both ends of the power supply to be measured via a shunt and a switch element, and opens the switch element for a short time to generate a rising slope of the current that starts from the time when the switch element is closed. By reading the current value at a predetermined point in time and calculating the resistance/inductance of the power supply from the read current value, the time constant of the line can be measured in the live state, and in this case, the time constant of the switch element can be measured in the live state. Because the time is extremely short, the breaker on the power distribution board does not trip, and there is no need for a large-capacity load device. Power loss during measurement can be drastically reduced, and at the same time, the superimposed DC component is attenuated to a negligible value. Since the power supply impedance is determined from the current value taken at the time of the measurement and the voltage drop value, the voltage drop ratio can be increased and measurement can be performed with high accuracy.Also, by using the same circuit as the time constant measurement , the cost of the measurement circuit is low and simple.
第１図は請求項１記載の発明の実施例の回路構成図、第
２図は同上使用の測定回路の回路構成図、第３図は同上
の動作説明用波形図、第４図は同上測定回路に使用する
ピークホールド回路の具体回路図、第５［！ｌは請求項
２記載の発明の実施例の回路構成図、第６図は同上の動
作説明用波形図、第７図は線路インピーダンスを測定す
る回路例の構成図、第８図は同上の動作説明用波形図で
ある。
Ｒ３は負荷抵抗、ＲＹ、はリレー、Ｋ１はリレー接点、
Ｅは電源、Ｚは電源インピーダンス、ａ。
ａ′は被測定電源端、Ａは電流計、１は測定回路、２は
制御回路、３ａ、３ｂはピークホールド回路、４は差動
増幅回路、５は積分回路、Ｌ、は電源のインダクタンス
、Ｒｏは電源の抵抗、Ｋ、はリレー接点、６は分流器、
７はデジタルメモリスコープである。Fig. 1 is a circuit configuration diagram of an embodiment of the invention as claimed in claim 1, Fig. 2 is a circuit configuration diagram of a measurement circuit used in the above, Fig. 3 is a waveform diagram for explaining the operation of the above, and Fig. 4 is a measurement of the same. Specific circuit diagram of the peak hold circuit used in the circuit, Part 5 [! 1 is a circuit configuration diagram of an embodiment of the invention according to claim 2, FIG. 6 is a waveform diagram for explaining the operation of the same, FIG. 7 is a configuration diagram of a circuit example for measuring line impedance, and FIG. 8 is an operation of the same as above. It is a waveform diagram for explanation. R3 is load resistance, RY is relay, K1 is relay contact,
E is the power supply, Z is the power supply impedance, a. a' is the power supply terminal to be measured, A is the ammeter, 1 is the measurement circuit, 2 is the control circuit, 3a, 3b are the peak hold circuits, 4 is the differential amplifier circuit, 5 is the integrating circuit, L is the inductance of the power supply, Ro is the resistance of the power supply, K is the relay contact, 6 is the shunt,
7 is a digital memory scope.
Claims (1)
とを介して負荷抵抗を接続し、上記スイッチ要素を電源
位相に同期して１サイクルおきに電流零点で投入して短
時間後に開放するとともに、この投入、開放によって得
られる被測定電源両端の無負荷時電圧のピークホールド
値と、負荷時電圧のピークホールド値との差電圧を多数
回積分し、該積分値を電圧降下値に変換して該電圧降下
値を上記電流測定手段で得た負荷電流で除することによ
り電源インピーダンスを測定することを特徴とする活線
の電源インピーダンス測定方法。（２）被測定電源の両
端に分流器とスイッチ要素とを介して負荷抵抗を接続し
、上記スイッチ要素を短時間閉じてスイッチ要素の閉じ
た時点から始まる電流の立ち上がり勾配期間の所定時点
の電流値を読み取り、この読み取った電流値より電源の
抵抗／電源のインダクタンスを求め、その後重畳直流分
が無視出来る値に減衰した時点で取り込んだ電流値と、
電圧降下値とより電源インピーダンスを求めることを特
徴とする活線の電源インピーダンスの測定方法。(1) A load resistor is connected to both ends of the power supply to be measured via a current measuring means and a switch element, and the switch element is turned on at the current zero point every other cycle in synchronization with the power supply phase, and then opened after a short period of time. At the same time, the difference voltage between the peak hold value of the no-load voltage across both ends of the power supply under test and the peak hold value of the voltage under load obtained by turning on and opening the power supply is integrated many times, and the integrated value is converted into a voltage drop value. A method for measuring power source impedance of a live line, characterized in that the power source impedance is measured by dividing the voltage drop value by the load current obtained by the current measuring means. (2) A load resistor is connected to both ends of the power supply to be measured via a shunt and a switch element, and the switch element is closed for a short time to generate a current at a predetermined point in the rising slope period of the current starting from the time when the switch element is closed. Read the value, calculate the resistance of the power supply/inductance of the power supply from this read current value, and then take the current value when the superimposed DC component has attenuated to a value that can be ignored.
A method for measuring the power supply impedance of a live wire, characterized by determining the voltage drop value and the power supply impedance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3421390A JPH03238367A (en) | 1990-02-15 | 1990-02-15 | Measurement of power source impedance for hot wire |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3421390A JPH03238367A (en) | 1990-02-15 | 1990-02-15 | Measurement of power source impedance for hot wire |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03238367A true JPH03238367A (en) | 1991-10-24 |
Family
ID=12407881
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3421390A Pending JPH03238367A (en) | 1990-02-15 | 1990-02-15 | Measurement of power source impedance for hot wire |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03238367A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003004781A (en) * | 2001-06-25 | 2003-01-08 | Kanto Denki Hoan Kyokai | Load device |
| JP2014109561A (en) * | 2012-12-04 | 2014-06-12 | Chugoku Electric Power Co Inc:The | Insulation resistance measuring device |
-
1990
- 1990-02-15 JP JP3421390A patent/JPH03238367A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003004781A (en) * | 2001-06-25 | 2003-01-08 | Kanto Denki Hoan Kyokai | Load device |
| JP2014109561A (en) * | 2012-12-04 | 2014-06-12 | Chugoku Electric Power Co Inc:The | Insulation resistance measuring device |
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