200806997 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種電流量測裝置，尤其是一種具有比 流器（current transformer，CT)之電流量測裝置。 ： - . . _ * . . . . _ 【先前技術】^ 現今電流里/則系用的方法包括比流器法、電阻壓降 法、霍爾（Hall)元件、法。其中，電阻壓降法無法與制 物分隔，而只能採用固定於待測物之設計方式。相較之下， 比流器法與霍爾元件法則無此限制，而適用於可移動之儀 元件法具有較佳之準確度，但是其電路較為複雜、成本較 有其產業利用上之價值。： -· \ _ . . .... 第-圖儀顯示-乘型比流器應之結構示意圖，而第二 圖係此比流器運作之等效電路圖。如财所示，—待測電 流源I (未圖示於第-圖)係連接至一導線10。此導線1〇 就電路上而言’可以相互串接之電阻rl與電感心 而與待測電流源I構成一初級迴路。 - .. . . · -. ... 此比流器20就結構上而言，係由一微磁芯） 之中心孔22a，而次級線圈24係纏_環狀磁芯22。而如 第-圖所示’此次級線圈24就電路上而言，可視為相互 接之-次級線圈電㈣與一次級線圈電感L2。通當 有-電壓伽電阻R串接至前述次級線圈電阻^與次級線 200806997 .圈電感L2，而構成一次級迴路2〇。 基本上，導線10係透過磁芯（c〇re) 22磁性耦合至 次級線圈24。因此，產生於初級迴路上的電流u係透過 此磁心22 ’在次級迴路2〇上產生一電動勢（e 1 ectr〇m〇uve force)’並藉由此電動勢在次級迴路2〇上形成另一個電流 12 〇 - · · ... , - . - . - . · 、 不過，如圖中所示，導線10與次級線圈24間亦會構 成一麵合電容C，而在次級線圈24上產生電容輕合訊號。 . 基本上’在低電壓或是低頻量測之情況下，由於由導線10 所引發，電場干擾並不明顯，因此，量測時電容耦合訊號 :之並不突顯。但是，當甩於量測高電壓或是高頻之電 流3τ’由導線1〇所引發之電容耦合訊號就會變得明顯。此 訊號會與待測訊號相重疊，而使量測之精確度嚴重下降。 - - . . . , · -. . . . · ·. . ... ^於疋’如何提高比流器量測方式之 广 」應用 <貝值的提升’有極為重要之影變。 - '· · · · ... . . · ..··..·· :【發明内容】 、本發日月之目的在於提供一種電流量測裝置，以比流器 紐行電流制。並且’鱗好難置可以獄防止電 容耦合訊號之干擾。 本發贿供—種驗量職置，顧量測-制電路 《電流值。此電流量測裝置包括-環狀磁S、-次級線圈、 200806997 .一隔離層與一放大電路。其中，環狀磁芯係環繞待測電路。 次級線圈係纏繞環狀磁芯。隔離層係實質上遮蔽次級線圈 與環狀磁芯’以阻擔次級線圈與待測電路間之靜電搞合。 並且，隔離層上形成有一開口，以消減因此隔離層所造成 之渦流（eddy current)損耗。放大電路係連接次級線圈， 以放大次級線圈上之電流。 . . . -. · . .. 本發明亦提供一種比流器，此比流器包括一環狀磁 _ 芯、一次級線圈與一隔離層。其中，環狀磁芯係環繞待測 馨 電路。次級線圈係纏繞環狀磁芯。隔離層係實質上遮蔽次 級線圈與環狀磁芯，以阻擋次級線圈與待測電路間之靜電 搞合。一開口係形成於隔離層上，以消減因隔離層所造成 之渦流（eddy current)損耗。 — . - .. . 關於本發明之優點與精神可以籍由以下的發明詳述及 丨所附圖式得到進一步的暸解。 .... …. :. . • . .. .... - _..:：:. . 广【實施方式】 、- . . ' : ·. 響 青參照第三圖所示，係本發明之電流量測裝置一較佳 實施例之電路示意圖。如圖中所示，此電流量測裝置包括 一環狀磁芯120、一次級線圈140、一隔離層160與一放大 電路200。其中，環狀磁芯12〇、次級線圈140與隔離層 160 係構成一比流器（current transformer，CT) 100。 - · - ' . . _ .. 放大電路200係連接至次級線圈140,以放大次級線圈14〇 上之電流訊號。次級線圈140的兩端係連接至放大電路 200,並且，在次級線圈140係中間接地G。同時，此比流 气100並設置有一負載電阻170並聯於次級線圈14〇。 200806997 同時請參照第五與五A圖’係第三圖中比流器loo的 結構示意圖。如圖中所示，環狀磁芯12〇係環繞待測電路 5〇，而次級線圈14〇係纏繞環狀磁芯12〇。此次級線圈14〇 之兩端係分別連接至一输出接腳150a與150b，以連接至 放大電路200。為了使次級線圈140中間接地，此比流器 1〇〇並^作有一接地接腳190連接至次級線圈14〇之中間 位置。 . .. . . ； - ： · ·. . · ..... - · · ·- . - . - ..... - - ， , - 隔離層160係實質上遮蔽次級線圈14〇與環狀磁怒 嫌 120。此隔離層16〇可以由導電石墨、銀、銅等導電材質， 以蒸鍍等方式所製作於一塑膠外殼上，然亦不限於此。 ... - ' - - . . 4於此隔離層16〇之存在’原本會形成於待測電路5〇 與次級線圈140間之耦合電容（請參照第二圖所示)，改為 形成衿待測電路50與隔離層160間，而可以有效阻擋次級 線圈140與待測電路50間之靜電耦合，避免在次級線亂 140上產生不必要之電容耦合訊號。 * ..... . . . ‘ ' . . ' 、. ^； -· ^ ； - ® (eddy current 感應訊號的品質。因此，本發明必須在隔離層16〇上形成 一開口 162，以消除因隔離層16〇之設置所造成之渦流損 耗。基本上，此開口 162之位置並未有特別之限制。然而'， 就一較佳實施例而言，如圖中所示，為兼顧製作之便利性 與消減渦流損耗之有效性，此開口 162可為一環狀切口， 位於對應於環狀磁芯120之内側壁處。 值得注意的是，由於此開口 162之存在，次級線圈14〇 與待測電路50間仍然可能存在靜電耦合，而在次級線圈 200806997 , . . · - - .140上產生少量電容耦合訊號。為了進一步去除此電容耦 合訊號，前述放大電路200可以採用一差動放大電路（如 第六圖所示），專以放大由環狀磁芯12〇感應待測電流（即 由磁場感應）所生之差動訊號。同時，次級線圈140係採 中間接地之設計’以有效排除來自待測電路50之靜電搞合 訊號〇 ... · . . · : 『_ .., . ·: 請參照第四圖％示，係本發明之電流量測裝置另一較 ’ 佳實施例之電落圖。此電流量測裝置包括一環狀磁芯 . . _ .. . · . - . - · ... 與170b與一放大電路200。其中，環狀磁芯12〇、次級線 圈140與隔離層160構成一比流器1〇〇。放大電路2〇〇係 連接至次級線圈140，以放大次級線圈140上之電流訊號。 相較於第三圖之實施例中僅具有_負載電阻17〇，本 實施例係使用二互相串接之負載電阻17〇&與17〇b，而此 二負載電阻170a與:170b係並聯於次級線圈14〇。此外， 参 四圖所示，本實施例除了可以將二貪栽電阻l7〇a與170b 相接之接點接地G以排除來自待測電路50之靜電耦合訊號 外;如第四A圖所示，本實施例亦可以在二負載電阻丨他 與170b間串接一中間接地之可變電阻172 ,以排除來自待 測電路50之靜電耦合訊號。 ’ 綜上所述’本發明之比流器100連過隔離層16〇之使 用，可以有效降低靜電耦合訊號之產生，同時搭配開口 162 製作’可以避免渦流耗損對於感應品質的影響。此設計 制對於高電壓與高頻環境之量測有其實益。惟在隔 200806997 160製作開口 162’尚可能使部分靜電鶴合訊穿 離層16㈣影響次級線㈣0上之電流職。因此牙^ 明同時使用差動放大電路咖，搭配次級、_ 14〇中間f 地之電路設計U是將二負_阻i衞與mb相接之接 點接地)，以進-步排除來自待晴路5()之靜鶴合訊號。 以上所述細聰佳實_詳細綱本發明，而非限 制本發明之翻’而且熟知此類技藝人士皆_瞭，適^ 而作鎌的改變及調整，仍將不失本發明之要義所在，^ 不脫離本發明之精神和範圍。 【圖式簡單說明】 ' 圓- -t - 第一圖係一典型比流器之結構示意圖。 第一圖係第一圖之比流器運作之等效電路圖。 第二圖係本發明比流器一較佳實施例之等效電路圖。 第四圖係本發明比流器另一較佳實施例之等效電路 國。 - . ' ； - ' / _. ·. ’ .. .… ：. 第四A圖係本發明比流器又一較佳實施例之等效電路 第五圖係本發明比流器一較佳實施例之結構示意圖。 第五A圖係第五圖之比流器的内部構造示意圖。 第六圖係一典型差動放大電路之電路圖。 200806997 【主要元件符號說明】 導線10 比流器20 環狀磁芯22 次級線圈24 • . * . m 中心孔22a 比流器100 環狀磁芯120 次級線圈140 . 、· .·200806997 IX. Description of the Invention: [Technical Field] The present invention relates to a current measuring device, and more particularly to a current measuring device having a current transformer (CT). : - . . _ * . . . _ [Prior Art] ^ Current current / method used in the current method includes the current comparator method, the resistance voltage drop method, the Hall element, and the method. Among them, the resistance voltage drop method cannot be separated from the product, but only the design method fixed to the object to be tested. In contrast, the comparator method and the Hall element rule have no such limitation, and the method for the movable device component has better accuracy, but the circuit is more complicated and the cost is more valuable in industrial utilization. : -· \ _ . . . . The first diagram shows the structure of the multiplier, and the second diagram is the equivalent circuit diagram of the comparator operation. As shown in the financial statement, the current source I to be tested (not shown in the figure) is connected to a wire 10. This wire 1〇 constitutes a primary loop with respect to the current source I to be tested, which can be connected in series with the resistor rl and the inductor. - . . . . . . . - The current transformer 20 is structurally a central core 22a of a micromagnetic core, and the secondary coil 24 is wound around the annular core 22. As shown in the figure - the secondary coil 24 is electrically connected to each other - the secondary coil (four) and the primary coil inductor L2. The current-voltage galvanic resistance R is connected in series to the aforementioned secondary coil resistance ^ and the secondary line 200806997. The coil inductance L2 constitutes a primary circuit 2 〇. Basically, the wire 10 is magnetically coupled to the secondary coil 24 through a magnetic core 22 . Therefore, the current u generated on the primary circuit transmits an electromotive force (e 1 ectr〇m〇uve force) on the secondary circuit 2' through the core 22' and is formed on the secondary circuit 2 by the electromotive force. Another current 12 〇 - · · ... , - . - . - . . . , However, as shown in the figure, the wire 10 and the secondary coil 24 will also form a combined capacitance C, while in the secondary coil A capacitive light signal is generated on the 24th. Basically, in the case of low voltage or low frequency measurement, the electric field interference is not obvious due to the lead 10, so the capacitive coupling signal during measurement is not highlighted. However, the capacitive coupling signal caused by the conductor 1 ’ when measuring the high voltage or the high frequency current 3τ' becomes apparent. This signal will overlap with the signal to be tested, and the accuracy of the measurement will be seriously degraded. - - . . . , · -. . . . . . . . . ^ ^ How to improve the scale of the flowmeter measurement method "Application < boosting the value of the shell" has a very important change. - '· · · · . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . And 'the scale is hard to set up to prevent the interference of the capacitive coupling signal. This bribe is a supply-measurement position, and the measurement-system circuit "current value. The current measuring device comprises a ring-shaped magnetic S, a secondary coil, 200806997. an isolation layer and an amplifying circuit. Wherein, the annular magnetic core surrounds the circuit to be tested. The secondary coil is wound around the toroidal core. The isolation layer substantially shields the secondary coil from the toroidal core to resist the static electricity between the secondary coil and the circuit under test. Also, an opening is formed in the isolation layer to reduce the eddy current loss caused by the isolation layer. The amplifying circuit is connected to the secondary coil to amplify the current on the secondary coil. The present invention also provides a flow comparator comprising an annular magnetic core, a primary coil and an isolation layer. Among them, the toroidal core surrounds the circuit to be tested. The secondary coil is wound around the toroidal core. The isolation layer substantially shields the secondary coil from the toroidal core to block static electricity between the secondary coil and the circuit under test. An opening is formed on the isolation layer to reduce eddy current loss caused by the isolation layer. The advantages and spirit of the present invention can be further understood from the following detailed description of the invention and the accompanying drawings. .... .... :. . . . . . . . - _..:::. . 广 [Embodiment], - . . ' : · · 青青 Refer to the third figure, the version A schematic circuit diagram of a preferred embodiment of the inventive current measuring device. As shown in the figure, the current measuring device comprises an annular core 120, a primary coil 140, an isolation layer 160 and an amplification circuit 200. The annular core 12 〇, the secondary coil 140 and the isolation layer 160 constitute a current transformer (CT) 100. - - - ' . . . The amplifier circuit 200 is connected to the secondary coil 140 to amplify the current signal on the secondary coil 14A. Both ends of the secondary coil 140 are connected to the amplifying circuit 200, and a grounding G is provided in the middle of the secondary coil 140. At the same time, this ratio of the flow gas 100 is provided with a load resistor 170 connected in parallel to the secondary coil 14A. 200806997 Please also refer to the fifth and fifth A diagrams for the structure diagram of the flow comparator loo in the third diagram. As shown in the figure, the toroidal core 12 is wound around the circuit under test 5 〇, and the secondary coil 14 is wound around the toroidal core 12 〇. Both ends of the secondary coil 14'' are connected to an output pin 150a and 150b, respectively, for connection to the amplifying circuit 200. In order to ground the secondary coil 140 in the middle, the current comparator 1 is connected to a ground pin 190 to be connected to the intermediate position of the secondary coil 14A. . . . . . . - . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The ring magnetic anger is 120. The spacer layer 16 can be made of a conductive material such as conductive graphite, silver or copper, and is formed on a plastic case by vapor deposition or the like, but is not limited thereto. ... - ' - - . . 4 The presence of the isolation layer 16 ' 'is originally formed in the coupling capacitance between the circuit under test 5 〇 and the secondary coil 140 (please refer to the second figure), to form Between the circuit under test 50 and the isolation layer 160, the electrostatic coupling between the secondary coil 140 and the circuit under test 50 can be effectively blocked to avoid unnecessary capacitive coupling signals on the secondary line 140. * ..... . . . ' ' . . ' , ' ^ ^ - - ^ ; - ® ( eddy current The quality of the inductive signal. Therefore, the present invention must form an opening 162 in the isolation layer 16 , to eliminate The eddy current loss due to the arrangement of the spacer layer 16. Basically, the position of the opening 162 is not particularly limited. However, in a preferred embodiment, as shown in the figure, Convenience and effectiveness of eddy current loss, the opening 162 may be an annular slit located at the inner sidewall corresponding to the annular core 120. It is noted that due to the presence of the opening 162, the secondary coil 14〇 There may still be electrostatic coupling between the circuit under test 50 and a small amount of capacitive coupling signal on the secondary coils 200806997, . . - - .140. To further remove the capacitive coupling signal, the amplifying circuit 200 may employ a differential The amplifying circuit (as shown in the sixth figure) is designed to amplify the differential signal generated by the toroidal core 12〇 sensing the current to be measured (ie, induced by the magnetic field). Meanwhile, the secondary coil 140 is designed to be grounded in the middle. 'to effectively exclude from The static electricity of the circuit to be tested 50 is combined with the signal 〇... · . . . : : _ _ . . , . . . : Please refer to the fourth figure %, which is another preferred embodiment of the current measuring device of the present invention. The current measuring device comprises a ring-shaped magnetic core. . . . . . . . . . . . . . . and 170b and an amplifying circuit 200. wherein the annular magnetic core 12〇, the secondary coil 140 and the isolation layer 160 constitute a current transformer 1 . The amplification circuit 2 is connected to the secondary coil 140 to amplify the current signal on the secondary coil 140. Compared with the embodiment in the third figure, only _ load resistor 17A, in this embodiment, two load resistors 17〇& and 17〇b are connected in series, and the two load resistors 170a and 170b are connected in parallel to the secondary coil 14〇. As shown in the figure, in addition to the grounding G of the contact point connecting the two soldering resistors l7〇a and 170b to exclude the electrostatic coupling signal from the circuit under test 50; as shown in FIG. 4A, this embodiment also An intermediate grounded variable resistor 172 can be connected in series between the two load resistors and 170b to eliminate the electrostatic coupling signal from the circuit under test 50. In summary, the use of the current transformer 100 of the present invention through the isolation layer 16 可以 can effectively reduce the generation of the electrostatic coupling signal, and at the same time, the opening 162 can be used to avoid the influence of the eddy current loss on the sensing quality. The measurement of high voltage and high frequency environment is beneficial. However, it is possible to make the opening 162' in the interval of 200806997 160 to make some static cranes pass through the layer 16 (four) to affect the current on the secondary line (4). Therefore, the teeth and the differential amplifier circuit are used at the same time, and the circuit design of the secondary, _ 14 〇 intermediate f ground is the grounding of the contact between the two negative _ resistance wei and the mb, to further exclude Jinghe Road 5 () Jinghe Hexun. The above is a detailed description of the present invention, and is not intended to limit the invention, and it is well known to those skilled in the art that the changes and adjustments of the present invention will remain without losing the essence of the present invention. , ^ does not depart from the spirit and scope of the present invention. [Simple description of the diagram] 'Circle - -t - The first diagram is a schematic diagram of a typical current transformer. The first figure is an equivalent circuit diagram of the operation of the current comparator of the first figure. The second drawing is an equivalent circuit diagram of a preferred embodiment of the present invention. The fourth figure is an equivalent circuit country of another preferred embodiment of the current comparator of the present invention. - ' / _. ·. ' .. .... :. The fourth A diagram is an equivalent circuit of a further preferred embodiment of the present invention. The fifth diagram is a preferred embodiment of the present invention. Schematic diagram of the structure of the embodiment. The fifth A is a schematic diagram of the internal structure of the current transformer of the fifth figure. The sixth diagram is a circuit diagram of a typical differential amplifier circuit. 200806997 [Description of main component symbols] Conductor 10 Current transformer 20 Annular core 22 Secondary coil 24 • . * . m Center hole 22a Current transformer 100 Annular core 120 Secondary coil 140 . , · .
隔離層160 V . ν'.'-'·:·:....- ... k 放大電路200 • ‘ - - . ·. - . · 将測電路50 輸出接腳150a，150b 開口 162 - - . .· 接地接腳190 負載電阻 170,170a，170b 11Isolation layer 160 V . ν'.'-'·:·:....- ... k Amplifying circuit 200 • ' - - . · - - · Measuring circuit 50 output pin 150a, 150b opening 162 - - . . . Grounding pin 190 Load resistance 170, 170a, 170b 11