201126185 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種市電倂聯型電流控制式電能轉換器 之孤島運轉债測方法，尤其是指一種僅在分散式發電系統 所產生之電能與總負載所消耗之電能平衡或電力系統故障 時，才對電流控制式電能轉換器之輸出電流進行擾動，以 判斷是否發生孤島運轉之偵測方法。 # 【先前技術】 小型發電系統或再生能源發電系統（如太陽能發電、 風力發電'燃料電池發電等），可視之為一分散式發電系 統，這些分散式發電系統可被併聯至市電電源系統，以供 電至負載。由於分散式發電系統與市電電源系統併聯運作 時必V頁有相_的保護機帝J，以確保運作時的安全性，其 中孤島運轉」谓測即是其中—種必要之保護機制。孤島 運㈣測係在市電電源系統因故障或維護等原因而切離 時’分散式發電系統持續供電而形成，此孤島運轉現象將 嚴重危。維修市電電源系統人員的安全與損壞電力設備。 因，，以下係簡略說明數件針對偵測孤島運轉的相關 中華民國發明專利公告第丨278635號係揭露一 種主動式的r挪i 動， 偵測方法J ，其利用對電力系統進行擾 ，二—高解析度之量測設備以偵測系統電壓頻率和大 作、=’再比較其前後差異並調整函數以決定-調整量， : 入微里之電流輸出頻率或是相位變化量，該 U壓大小與系統電屢頻率來判斷是否發生孤島運⑸ 3 201126185 轉 "此方法需對電力系統持續擾動，其有影響電力品質 之缺點，且需高解析度量測設備，導致量測成本增加。 如美國專利第 7,275,002 號（丨slanding detection and protection method ) ’係揭露一種利用改變負相序電壓量 來擾動電力系 '統’偵測系統電壓頻率之變化來判定是否發 生孤島運轉’冑電力系統斷電產生孤島運轉時，因注入負 相序電壓，故使系統電壓產生頻率料，利用正迴授方式 加I·夬系統電壓頻率之漂移量，因而偵測出發生孤島運轉。 但此方法需改變負相序電壓量來持續擾動電力系統，故只 適用於三相電力系、統’且對電力系統持續擾動，故亦影響 到電力品質。 7,106,564 ^ (Devices and methods for detecting is,ending 〇perati〇n of a statjc p〇W0r source) ’係先利用一電能轉換器與市電電麼鎖相，而電 月匕轉換盗所產生之雷愿瓶、玄拉j , &頻率與市電電壓頻率有些微的變 化’並判斷此次電壓頻率盥上兮 干，、上-人電壓頻率之變化量，若沒 大於最小頻率變化量時，表示 ▲ 帀電正吊，則每週期將重新 改變電能轉換器輸出電壓頻率· 頊半，反之，若此次電壓頻率與 上次電壓頻率變化量大於最小 用平變化置之設定值時，將 會累積頻率變化量，將下次輸出雷厭相玄μ 人将』出電壓頻率變動量與上次相 加’再次偵測市電頻率是否 一㈤士 吊右市電頻率超出正常值 乾圍時，表不發生孤島運轉。伸 m^ 仁此方法同樣是對電力系統 持續擾動’故會影響到電力品質。 【發明内容】 201126185 電 質 由於目前已知的 力系統進行持續性 主動式孤島運轉偵測方法， 地擾動，故會影響電力系統之電需力要:: 有鑑於此，本發明之主要目 電流控制式電能轉換器之孤島運轉種：電併聯型 正常且分散式發電 偵測方法，在電力系統 能™ 電能與總負載所消耗之電201126185 VI. Description of the Invention: [Technical Field] The present invention relates to an islanding operation debt measuring method for a commercial power-coupled current-controlled power converter, and more particularly to a power generated by a distributed power generation system only When the power balance of the total load or the power system fails, the output current of the current-controlled power converter is disturbed to determine whether or not the islanding operation detection method occurs. # [Prior Art] Small power generation systems or renewable energy power generation systems (such as solar power, wind power, fuel cell power generation, etc.) can be regarded as a decentralized power generation system. These distributed power generation systems can be connected in parallel to the mains power system to Power is supplied to the load. Since the decentralized power generation system operates in parallel with the mains power supply system, the V-page has a phase-protection machine J to ensure the safety during operation, and the island operation is the necessary protection mechanism. The island transport (4) measurement system is formed when the mains power system is disconnected due to failure or maintenance, etc. The distributed power generation system is continuously powered, and the island operation phenomenon will be seriously dangerous. Repair the safety and damage of power equipment for utility power system personnel. Therefore, the following is a brief description of several pieces of the relevant Republic of China invention patent announcement No. 278635, which discloses an active r-movement, detection method J, which utilizes the power system to interfere, - High-resolution measurement equipment to detect system voltage frequency and masterpiece, = 'recombine the difference between before and after and adjust the function to determine - adjustment amount, : the current output frequency or phase change amount into the micro-Li, the U pressure size It is determined by the frequency of the system and the frequency of the system. (5) 3 201126185 Turn " This method requires continuous disturbance of the power system, which has the disadvantage of affecting the power quality, and requires high-resolution measurement equipment, resulting in an increase in measurement cost. For example, U.S. Patent No. 7,275,002 (丨slanding detection and protection method) discloses a method of changing the voltage of a negative phase sequence to disturb the change of the voltage frequency of the power system to determine whether or not an island operation occurs. When the island is operated, the negative phase sequence voltage is injected, so that the system voltage is generated, and the drift of the voltage frequency of the I·夬 system is added by the positive feedback method, thereby detecting the islanding operation. However, this method needs to change the negative phase sequence voltage amount to continuously disturb the power system, so it is only applicable to the three-phase power system, and the power system continues to be disturbed, thus affecting the power quality. 7,106,564 ^ (Devices and methods for detecting is,ending 〇perati〇n of a statjc p〇W0r source) 'First use a power converter to lock the phase with the mains, and the fertile bottle generated by the electric moon converts the stolen , Xuan La j , & frequency and the mains voltage frequency slightly change 'and determine the voltage frequency 盥 兮 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , When the electric crane is hanging, the frequency of the output voltage of the power converter will be changed again every half cycle. Otherwise, if the voltage frequency and the previous voltage frequency change are greater than the set value of the minimum flat change, the frequency change will be accumulated. The amount will be the next time the output will be reversed, and the output voltage will be added to the last time. 'Re-detecting whether the mains frequency is one (five). When the right mains frequency exceeds the normal value, the island operation does not occur. . This method is also a continuous disturbance to the power system, which will affect the power quality. SUMMARY OF THE INVENTION 201126185 Electric power due to the current known force system for continuous active island operation detection method, ground disturbance, it will affect the power demand of the power system: In view of this, the main current of the present invention The islanding operation of the controlled power converter: the electric parallel type normal and distributed power generation detection method, the power consumed by the power system TM power and the total load
電…流控制式電能轉換器之輸出電流並不會對 電力系統進行擾動；反之，只有在分.散式發電系统所= 總負載所消耗之電能平衡或電力系統故障時，電 式電能轉換器才會對電力系統進行擾動，以 否發生孤島運轉。 為達成前述目@，本發明市電併聯型電流控制式電能 轉換器之孤島運轉偵測方法係包含：The output current of the current-controlled flow converter does not disturb the power system; conversely, the electric energy converter is only used when the distributed power system is equal to the power balance consumed by the total load or the power system is faulty. The power system will be disturbed to see if island operations occur. In order to achieve the above-mentioned object, the islanding operation detection method of the commercial parallel-type current-controlled power converter of the present invention comprises:
將〃政式發電系統連接至一市電電源，並供電給— 負載’其該分散式發電系統包含有—直流電能及一電 流控制式電能轉換器，其提供—實功率至該市電電源； 將該市t電源之市電電流取絕對i，若該絕對值大於 —預先設定之誤差冑’則判定該市電電源為JLf，令該電 流控制式電能轉換器不產生一孤島偵測擾動信號；及 若該市電電源之市電電流其絕對值小於該預先設定之 誤差值，令電流控制式電能轉換器產生一孤島偵測擾動信 號，並重新偵測該市電電流並取其絕對值，若該絕對值仍 疋小於泫預先設定之誤差值，即判斷為發生孤島運轉現 象’並將該市電電源與分散式發電系統解聯。 S.1 本發明之另一目的係提供一種市電倂聯型電流控制式 5 201126185 電能轉換器之孤島運轉偵測方法’係應用於具有一市電電 源、一分散式發電系統及一負載之電力系統，該市電電源 經由一第一電磁開關而連接該負載’該分散式發電系統則 經由一第二電磁開關連接該負載，該方法包含： a ·偵測一市電電流； b_對該市電電流取絕對值，判斷該絕對值是否大於一 預先設定之誤差值； C.若該絕對值大於該預先設定之誤差值，則將一孤島 _ 偵測擾動信號設定為零，並控制該第一電磁開關與第二電 磁開關閉合，使市電電源及分散式發電系統與該負載連 接，並回歸前述步驟a; d_若該絕對值小於該預先設定之誤差值，係將孤島偵 測擾動信號設定不為零，並再次重新偵測市電電流； e. 對該重新偵測之市電電流取絕對值，判斷該絕對值 是否大於該預先設定之誤差值； f. 若該絕對值大於該預先設定之誤差值，係執行前述 籲步驟c ; g. 若該絕對值小於該預先設定之誤差值，係判定為發 生孤島運轉，並控制該第一電磁開關與第二電磁開關打 開’使市電電源及分散式發電系統與該負載斷離。 藉由前述技術手段，本發明於市電電源正常供電而分 散式發電系統所產生之電能和負载所消耗總電能未達到平 衡時，該電流控制式電能轉換器不會加入一孤島偵測擾動 信號，以維持良好的供電品質，保持較低總諧波失真率。 實際上，分散式發電系統所產生電能與負載總消耗之電能 201126185 達到功率平衡其發生的機會極少，且發生之時間甚短，因 此本發明所提出之孤島運轉偵測方法不但能準確偵測出孤 島運轉’且不需要持續擾動電流控制式電能轉換器之輸出 電流’所以可大幅減少擾動分散式發電系統之時間與次數， 以維持良好的供電品質。 再者’市電電源異常時’電流控制式電能轉換器透過 輸出電流擾動，亦可有效的判斷出是否發生孤島運轉現象。 【實施方式】 請參考第一圖所示’本發明係可應用於此電源系統 架構，該電源系統主要包含一市電電源（10)、一分散式發 電系統（20)、一負載（30) ' —第一電磁開關（4〇)與一第二 電磁開關（50)，其中分散式發電系統（2〇)係由一直流電能 (21)與一電流控制式電能轉換器（22)所組成，而市電電源 (1〇)係提供—市電電源電壓（11)與一市電電流（12)，該市 電電源（10)經由該第一電磁開關（4〇)而連接至該負載 ()°亥刀散式發電系統（2 〇)則經由該第二電磁開關（5 〇) 連接至該負載（3〇)。 本發明所提出孤島運轉偵測方法之技術特點除了有效 偵測出孤島運轉以外，與其它主動式偵測孤島運轉方法最 大不同即在於，當市電電源（10)正常與有能量進出市電電 源（1〇)時，分散式發電系統（20)並不會對電力/系統進行擾 動’可提尚整體電力品質；反之’本發明之孤島偵測技術 只有在市電電源（1〇)斷電或當分散式發電系統（2〇)所產生 之電能恰巧等於負載(30)所消耗電能時，彳會於電流控制 201126185 式電能轉換器（2 2)輪出電流加入一孤島僧測擾動信號△丨來 判斷是否發生孤島’運轉，其基本原理說明如下： 首先’請參考第二圖所示’本發明分散式發電系統之 孤島運轉偵測方法係由該電流控制式電能轉換器（22)所實 現’該電流控制式電能轉換器（22)為一電流控制式直流/交 流電能轉換器’不但具有主動式電力濾波器之功能，同時 具有能量回送之功能’因此不論負載（3〇)是否為非線性負 載或任一負載，市電電流（1 2)將會被控制為一純正弦波電 • 流’其相位與市電電源電壓（11)同相位或相位相反（相差18〇 度），假設市電電源電壓（1彳）可由下式表示為 vi(〇=FJsin(i〇/) (1) 非線性負載電流可表示為 〇0 L ζ /„ Sin(_ + <9„) (2) 經由該電流控制式電能轉換器（22)產生一補償電流進 行補償後，其市電電流（12)將可表示為 ύη(ωή (3) 籲 在第（3)式中，定義為市電電流（12)與市電電源電壓 (1 1)同相位，而實功電力潮流從市電電源（1〇)流入負載 (30)，相對的，-/“定義為市電電流（12)與市電電源電壓（1 ” 相位相反（互差180度）’實功電力潮流從分散式發電系統 (20)流向市電電源（1〇)中。 因此，電流控制式電能轉換器（22)產生之補償電流之 參考信號可經由計算得出為 (4) 201126185 若電流控制式電能轉換器（22)輸出電流為ζ·,ΰη(ί)，則市 電電流（12〉將會是正弦波電流，該市電電流（12)相位會與 市電電源電壓（11)同相位或相位相反（相差1 80度）。 主動式電力濾波器其功效主要是在任一負載下，如非 線性負載，市電電流（1 2)皆能有效控制並保持為一純正弦 波電流且與市電電源電壓（11)同相位或相位相反（相差】8〇Connecting the utility power generation system to a utility power supply and supplying power to the load - the distributed power generation system includes - DC power and a current controlled power converter, providing - real power to the utility power supply; The city electric current of the city t power source takes absolute i, and if the absolute value is greater than - the preset error 胄 ', it is determined that the mains power source is JLf, so that the current control type power converter does not generate an island detecting disturbance signal; The absolute value of the mains current of the mains power supply is less than the preset error value, so that the current control type electric energy converter generates an island detecting disturbance signal, and re-detects the main current and takes the absolute value thereof, if the absolute value is still 疋If it is smaller than the preset error value, it is judged that the islanding phenomenon occurs, and the mains power supply and the distributed power generation system are disconnected. S.1 Another object of the present invention is to provide a mains power connection type current control type 5 201126185 power converter islanding operation detection method is applied to a power system having a mains power supply, a distributed power generation system and a load The mains power source is connected to the load via a first electromagnetic switch. The distributed power generation system is connected to the load via a second electromagnetic switch, and the method comprises: a: detecting a mains current; b_ taking the mains current Absolute value, determining whether the absolute value is greater than a preset error value; C. if the absolute value is greater than the preset error value, setting an island_detection disturbance signal to zero, and controlling the first electromagnetic switch And closing the second electromagnetic switch, connecting the mains power supply and the distributed power generation system to the load, and returning to the foregoing step a; d_ if the absolute value is less than the preset error value, setting the island detection disturbance signal to not Zero, and re-detect the mains current again; e. Take the absolute value of the re-detected mains current to determine whether the absolute value is greater than the preset error f. If the absolute value is greater than the preset error value, the foregoing step c is performed; g. if the absolute value is less than the preset error value, it is determined that an islanding operation occurs, and the first electromagnetic switch is controlled And the second electromagnetic switch is turned on 'to disconnect the mains power supply and the distributed power generation system from the load. According to the foregoing technical means, when the power supply of the mains power supply is normal and the power generated by the distributed power generation system and the total power consumed by the load are not balanced, the current control type power converter does not add an island detecting disturbance signal. To maintain good power quality, maintain a low total harmonic distortion rate. In fact, the power generated by the distributed power generation system and the total energy consumed by the load 201126185 reach a power balance, and the chance of occurrence is extremely small, and the time of occurrence is very short. Therefore, the island operation detection method proposed by the present invention can accurately detect not only The island operation 'does not need to continuously disturb the output current of the current-controlled power converter', so the time and number of disturbances of the distributed power generation system can be greatly reduced to maintain good power quality. Furthermore, when the mains power supply is abnormal, the current-controlled electric energy converter can effectively determine whether or not the islanding operation occurs due to the disturbance of the output current. [Embodiment] Please refer to the first figure. The present invention can be applied to the power system architecture. The power system mainly includes a mains power supply (10), a distributed power generation system (20), and a load (30). a first electromagnetic switch (4〇) and a second electromagnetic switch (50), wherein the distributed power generation system (2〇) is composed of a direct current power (21) and a current controlled power converter (22). The mains power supply (1〇) provides a mains supply voltage (11) and a mains current (12), and the mains supply (10) is connected to the load () by the first electromagnetic switch (4〇) The distributed power generation system (2 〇) is connected to the load (3 〇) via the second electromagnetic switch (5 〇). The technical features of the islanding operation detection method proposed by the present invention are different from other active detection island operation methods except that the islanding operation is effectively detected, that is, when the commercial power source (10) is normal and has energy to enter and exit the utility power source (1) 〇), the distributed power generation system (20) does not disturb the power/system' to improve the overall power quality; otherwise, the island detection technology of the present invention is only powered off or dispersed when the mains power supply (1〇) When the power generated by the power generation system (2〇) is exactly equal to the power consumed by the load (30), it will be judged by the current control 201126185 type electric energy converter (2 2) rotating current added to an island measuring disturbance signal △丨Whether the island operation is performed or not, the basic principle is as follows: First, please refer to the second figure. The islanding operation detection method of the distributed power generation system of the present invention is realized by the current control type power converter (22). The current-controlled power converter (22) is a current-controlled DC/AC power converter that not only has the function of an active power filter, but also has energy The function of sending 'so the mains current (1 2) will be controlled to a pure sine wave current · flow 'with the same phase as the mains supply voltage (11), regardless of whether the load (3〇) is a non-linear load or any load The phase or phase is opposite (18 degrees difference), assuming that the mains supply voltage (1彳) can be expressed as vi(〇=FJsin(i〇/) (1). The nonlinear load current can be expressed as 〇0 L ζ /„ Sin(_ + <9„) (2) After the compensation current is generated by the current-controlled power converter (22), the mains current (12) can be expressed as ύη(ωή (3) In the formula (3), the mains current (12) is defined as the same phase as the mains supply voltage (1 1), and the actual power flow flows from the mains supply (1〇) into the load (30). In contrast, -/ is defined as The mains current (12) is opposite to the mains supply voltage (1 ” phase (180 degrees difference). The actual power flow flows from the distributed power generation system (20) to the mains supply (1〇). Therefore, the current-controlled power converter (22) The reference signal of the generated compensation current can be calculated as (4) 201126185 If current control The output current of the power converter (22) is ζ·, ΰη(ί), then the mains current (12> will be a sine wave current, and the phase of the mains current (12) will be in phase or phase with the mains supply voltage (11). On the contrary (the difference is 1 80 degrees). The active power filter is mainly used under any load, such as non-linear load, the mains current (1 2) can effectively control and maintain a pure sine wave current and the mains supply voltage (11) The same phase or phase is opposite (phase difference) 8〇
度）。此電流控制式電能轉換器（22)所控制的方式為利用功 率平衡觀念’使市電電流（12)的大小相依於系統中該市電 電源（10)、分散式發電系統（20)與負載（30)之功率平衡。 在電壓源型電流控制式電能轉換器中，該電流控制式 電能轉換器（22)之直流匯流排上安置一直流電容器，作為 月色量儲存與緩衝器以調整直流匯流排電壓（23) ^在系統穩 •4時，市電電源（10)所提供之實功電能、分散式發電系統（2〇) 所產生之實功電能與負載（30)所消耗之實功電能三者將會 達到平衡，因此，直流匯流排電壓（23)之平均值會達到一 穩定常數值。若因負載（30)瞬間變動使系統功率未達平衡 時，則直流電容器必需提供市電電源（1〇)與負載（3〇)所相 差之電能’因此’電流控制式電能轉換器(22)必需調整直 流電容器上之直流匯流排電壓(23)。若市電電源⑽與直 流電能(2”所產生之實功小於負載(3〇)所消耗之實功時， 其直流匯流排電壓(23)將會降低，此時，電流(12)的 控制命令值將會增加，即為增加市電電流（12)，使市電電 源⑽所提供之實功量增加而達到功率平衡。反之，若因 負綱瞬間變動使市電電源(1〇)與直流電能(2”所產生之 實功大於負載(30)所消耗實工力’造成系統功率無法平衡， 201126185 其直流匯流排電壓（23)將會上升，此時，市電電流（彳2)的 控制命令值將會減小，即為降低市電電流（12)，減少市電 電源（1 0)所提供之實功量而達到功率平衡。因此，調整直 流匯流排電壓（23)即可控制市電電流（12)之大小，並使整 體系統達到功率平衡。 該電流控制式電能轉換器（22)之控制方式需要偵測三 個回授信號，分別為一市電電源電壓信號、一直流匯流排 電壓信號與一市電電流信號。市電電源電壓（1 0)經由一第 一電壓檢出器（605)檢測出其電壓信號並輸入至一波形產生 器（606) ’ s亥波形產生器（6〇6)產生一與市電電源電壓（1〇) 同頻率同相位之正弦波參考信號’而調整直流匯流排電壓 (23)主要是用來提供市電電源（1 〇)、分散式發電系統（20)與 負載（30)之功率平衡。直流匯流排電壓（23)經由一第二電 壓檢出器（600)檢出電壓信號後，與一直流設定電壓共同輸 入至一減法器（601)相減，產生一直流電壓誤差信號，將該 電壓誤差信號輸入至一比例積分控制器（6〇2)而產生—市電 電流振幅控制信號’該直流設定電壓是考慮於穩態時，依 電流控制式電能轉換器（22)必需之直流匯流排電壓（23)的 大小而決定。將該市電電流振幅控制信號輸入一加法器 (604)與孤島偵測擾動信號△ |相加而產生一市電電流振幅 之參考信號’該市電電流振幅參考信號是用來控制市電電 流（1 2)的振幅，本發明所提出之分散式發電系統之孤島運 轉偵測方法如第三圖所示，其產生一孤島偵測擾動信號△ 丨’此擾動信號將注入於第二圖所示之孤島偵測擾動信號△ 丨，若市電電流之絕對值大於預先設定之誤差值，則孤島偵 201126185 測擾動信號△丨為零；反之，若市電電流之絕對值小於預 先設定之誤差值m貞測擾動信號為△丨其值將不等於 零。 、 波形產纟器（606)之輸出與該參考冑電電流振幅信號係 輸入一乘法器（607)相乘以獲得一市電電流參考信號，其相 位與市電電源電壓同相位或相位相反（相差1 8〇度）。 而市電電流（12)經由一電流檢出器（6〇8)獲得電流信號 後，與該市電電流參考信號輸入一減法器（6〇9)相減獲得一 市電電流誤差信號。將此市電電流誤差信號送入一誤差放 大器（610)，誤差放大器（61〇)之輸出信號並再傳送至一驅 動電路（611)後，經一驅動電路（611)產生一驅動信號以驅 動電流控制式電能轉換器（22)之電力電子開關。 請參考第三圖所示，為本發明之孤島運轉偵測方法流 程圖，其主要步驟如下： 偵測市電電流（701); 判斷市電電流（12)之絕對值是否大於一預先設定之誤 差值W702); 若所偵測之市電電流（1 2)之絕對值大於預先設定之誤 差值Ierr時’則孤島損測擾動信號△丨設定為零，且第一與 第二電磁開關（40)(50)閉合，令市電電源（1 〇)與分散式發電 系統（20)維持連接於負載（30)(706〉，電流控制式電能轉換 器（22)不產生電流擾動並持續運轉； 反之，若偵測市電電流（1 2)之絕對值小於預先設定之 誤差值I…時，則孤島偵測擾動信號△丨不等於零（7〇3)， 預先設定之誤差值是為了避免量測上的誤差，其值非 11 201126185 常小但卻不等於零； 因此’將孤島偵測擾動信號△丨加入電流控制式電能 轉換器（22)之控制’並重新偵測市電電流（12) (7〇4); 判斷市電電流（12)之絕對值是否大於預先設定之誤差 值 （705); 若所偵測到的市電電流（12)之絕對值大於預先設定之 誤差值Ierr時’表示目前市電電源（1〇)正常，只是分散式 發電系統（20)所產生之電能恰巧與負載（3〇)所消耗的總電 • 能相等，因此，令孤島偵測擾動信號△I設定為零，第一 與第二電磁開關（40)(50)閉合（706)，該電流控制式電能轉 換器（22)不產生電流擾動並持續運轉； 反之’經由加入不等於零之孤島偵測擾動信號△丨後 所伯測到的市電電流（12)之絕對值仍然小於預先設定之誤 差值Ierr時，表示偵測出分散式發電系統（2〇)正處於孤島運 轉中’因此將第一與第二電磁開關（4〇)(5〇)打開（7〇7)，使 分散式發電系統（20)切離市電電源（1〇)，並切離負載（3〇)， 鲁停止系統運轉。 本發明所提出的孤島運轉偵測方法為在市電電流（彳2) 幾乎等於零的時候加入一不等於零之電流振幅擾動量 以破壞整體系統功率平衡，如果市電電流（12)仍幾乎等於 零時’將可偵測出孤島運轉，此也表示經過市電電流（12) 加入一不等於零之振幅擾動量△丨來破壞實功平衡後，市 電電源（10)側依然沒有市電電流（12)流動。因此，本發明 所提出之孤島偵測方法在最困難偵測之情況下，依然能有 效偵測出孤島運轉。 [s.l 12 201126185degree). The current-controlled power converter (22) controls the power balance concept to make the mains current (12) dependent on the mains power supply (10), the distributed power generation system (20) and the load (30) in the system. The power balance. In the voltage source type current control type power converter, a DC capacitor is arranged on the DC bus of the current control type power converter (22) as a moon color storage and buffer to adjust the DC bus voltage (23) ^ When the system is stable, the real power of the mains power supply (10), the actual power generated by the distributed power generation system (2〇) and the actual power consumed by the load (30) will be balanced. Therefore, the average value of the DC bus voltage (23) will reach a stable constant value. If the power of the system is not balanced due to the instantaneous change of the load (30), the DC capacitor must provide the difference between the mains supply (1〇) and the load (3〇). Therefore, the current-controlled power converter (22) must be Adjust the DC bus voltage on the DC capacitor (23). If the actual power generated by the mains power supply (10) and DC power (2) is less than the actual power consumed by the load (3〇), the DC bus voltage (23) will decrease. At this time, the current (12) control command The value will increase, that is, to increase the mains current (12), so that the actual power provided by the mains supply (10) will increase to achieve power balance. Conversely, if the negative power changes, the mains supply (1〇) and DC power (2) The actual power generated is greater than the actual working force of the load (30), which causes the system power to be unbalanced. The DC bus voltage (23) will rise in 201126185. At this time, the control command value of the mains current (彳2) will be Will reduce, that is, to reduce the mains current (12), reduce the amount of real power provided by the mains supply (10) to achieve power balance. Therefore, adjust the DC bus voltage (23) to control the mains current (12) The size and the overall system reach the power balance. The control mode of the current-controlled power converter (22) needs to detect three feedback signals, which are a mains supply voltage signal, a constant current bus voltage signal and a mains current. Signal. City The electrical power supply voltage (10) detects its voltage signal via a first voltage detector (605) and inputs it to a waveform generator (606)'s waveform generator (6〇6) to generate a voltage with the mains supply. (1〇) The sinusoidal reference signal with the same phase and the DC bus voltage (23) is mainly used to provide the power balance between the mains supply (1 〇), the distributed generation system (20) and the load (30). The DC bus voltage (23) is detected by a second voltage detector (600), and is input to a subtractor (601) together with the DC set voltage to generate a DC voltage error signal. The voltage error signal is input to a proportional integral controller (6〇2) to generate a mains current amplitude control signal. The DC set voltage is a DC sink necessary for the current controlled power converter (22) in consideration of steady state. The size of the discharge voltage (23) is determined. The mains current amplitude control signal is input to an adder (604) and the island detection disturbance signal Δ | is added to generate a reference signal of the mains current amplitude. The test signal is used to control the amplitude of the mains current (1 2). The islanding operation detecting method of the distributed power generation system proposed by the present invention is as shown in the third figure, which generates an island detecting disturbance signal Δ 丨 'this disturbance The signal will be injected into the island detection disturbance signal △ 所示 shown in the second figure. If the absolute value of the mains current is greater than the preset error value, the island detector 201126185 will detect the disturbance signal △丨 is zero; otherwise, if the city current is absolute The value is less than the preset error value m. The disturbance signal is Δ丨, and its value will not be equal to zero. The output of the waveform generator (606) is multiplied by the reference 胄 electric current amplitude signal by a multiplier (607). A mains current reference signal is obtained, the phase of which is in phase or phase opposite to the mains supply voltage (a difference of 18 degrees). After the mains current (12) obtains the current signal via a current detector (6〇8), it is subtracted from the mains current reference signal input to a subtractor (6〇9) to obtain a mains current error signal. The mains current error signal is sent to an error amplifier (610), and the output signal of the error amplifier (61〇) is transmitted to a driving circuit (611), and a driving signal is generated by a driving circuit (611) to drive the current. A power electronic switch for a controlled power converter (22). Please refer to the third figure, which is a flow chart of the island operation detection method of the present invention. The main steps are as follows: detecting the mains current (701); determining whether the absolute value of the main current (12) is greater than a preset error value. W702); If the detected mains current (1 2) absolute value is greater than the preset error value Ierr' then the island damage measurement disturbance signal Δ丨 is set to zero, and the first and second electromagnetic switches (40) ( 50) closing, so that the mains power supply (1 〇) and the distributed power generation system (20) are connected to the load (30) (706>, the current-controlled power converter (22) does not generate current disturbance and continues to operate; When the absolute value of the detected mains current (1 2) is less than the preset error value I..., the island detection disturbance signal △丨 is not equal to zero (7〇3), and the preset error value is to avoid the error in the measurement. The value is not 11 201126185 is always small but not equal to zero; therefore 'add the island detection disturbance signal △ 丨 to the control of the current-controlled power converter (22)' and re-detect the mains current (12) (7〇4) ; Judging the absolute value of the mains current (12) Whether the value is greater than the preset error value (705); if the detected absolute value of the commercial current (12) is greater than the preset error value Ierr, 'the current commercial power supply (1〇) is normal, only the distributed power generation system (20) The generated electric energy happens to be equal to the total electric energy consumed by the load (3〇). Therefore, the island detecting disturbance signal ΔI is set to zero, and the first and second electromagnetic switches (40) (50) Closed (706), the current-controlled power converter (22) does not generate current disturbance and continues to operate; otherwise, the absolute value of the mains current (12) detected by detecting the disturbance signal Δ丨 by adding an island not equal to zero When the value is still less than the preset error value Ierr, it means that the distributed power generation system (2〇) is detected to be in the island operation. Therefore, the first and second electromagnetic switches (4〇) (5〇) are turned on (7〇 7), the distributed power generation system (20) is cut off from the mains power supply (1〇), and the load is cut off (3〇), and the system is stopped. The islanding operation detection method proposed by the present invention is the current in the mains (彳) 2) Join one when it is almost equal to zero A current amplitude disturbance equal to zero to destroy the overall system power balance. If the mains current (12) is still almost equal to zero, 'island operation will be detected, which also means that the mains current (12) is added to an amplitude disturbance amount that is not equal to zero. After the actual power balance is broken, there is still no mains current (12) flowing on the mains power supply (10) side. Therefore, the island detection method proposed by the present invention can effectively detect the islands under the most difficult detection conditions. Operation. [sl 12 201126185
一般主動式m島運㈣測方法是制—擾動信號持續 加入市電併聯型電能轉換器之輸出電流，比較傳統主動式 孤島運轉谓測方法’本發明所提出孤島運轉偵測方法之優 在市電電源。0)正常供電，且分散式發電系統(2〇)所產 生之電能和負載(30)所消耗總電能未達到平衡時，電流控 制式電能轉換器（22)並不會加人擾動㈣，使市電電流波 形可達到近似正弦&，並且與市電電源㈣⑴）同相位或 相位相反（相| 18〇度），因此市電電流（12)可—直保持較 低總諸波失真_ ’而實際應用上，分散式發電系統_ 產生電能與負載（30)總消耗之電能達到功率平衡發生之機 會極且發生之時間甚短’因此本發明所提出孤島運轉 摘測方法不但能準確偵測出孤島運轉，且不需要持續擾動 電流控制式電能轉換器(22)輸出電流，將會大幅減少擾動 分散式發電系統（20)之時間與次數。 以上所述者，皆僅為本發明之較佳實施例而已，並非 用限定本發明實施之範圍。即凡依本發明之申請專利範圍 由熟悉本案f景技#之人士任施匠思而為諸般修飾，皆不 脫如附申請專利範圍所欲保護者，而為本發明專 涵蓋。 【圖式簡單說明】 第-圖：本發明市電電源系統與分散式發電系統之架 構圖。 第二圖：結合本發明分散式發電系統之孤島運轉傾測 法之電流控制式電能轉換器其控制方塊圖。 13 201126185 第三圖：本發明之孤島運轉偵測方法之流程圖。The general active m island transport (four) test method is to make the disturbance current signal continuously input to the output current of the commercial parallel power converter, and compare the traditional active island operation test method. The island operation detection method proposed by the present invention is superior to the utility power source. . 0) If the power generated by the distributed power generation system (2〇) and the total power consumed by the load (30) are not balanced, the current-controlled power converter (22) will not be disturbed (4), so that The mains current waveform can be approximated to sine & and is in phase or phase opposite to the mains supply (4)(1)) (phase | 18〇), so the mains current (12) can be kept straight and low total wave distortion _ 'and practical application Above, decentralized power generation system _ generating electrical energy and load (30) total consumption of electrical energy to achieve a power balance occurs very unlikely and occurs for a short time 'Therefore, the islanding operation sampling method proposed by the present invention can not only accurately detect island operation Without the need to continuously perturb the output current of the current-controlled power converter (22), the time and frequency of disturbing the distributed power generation system (20) will be greatly reduced. The above are only the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. That is, the scope of the patent application according to the present invention is modified by those skilled in the art, and is not intended to be protected by the scope of the patent application, and is specifically covered by the present invention. [Simplified description of the drawings] Fig.: A block diagram of the mains power supply system and the distributed power generation system of the present invention. Second: A control block diagram of a current controlled power converter incorporating an islanding tilting method of the distributed power generation system of the present invention. 13 201126185 Third figure: Flow chart of the island operation detection method of the present invention.
【主要元件符號說明】 (10)市電電源 (11)市電電源電壓 (1 2)市電電流 (20)分散式發電系統 (21)直流電能 (22)電流控制式電能轉換器 (23)直流匯流排電壓 (30)負載 (40)第一電磁開關 (50)第二電磁開關 (600)第二電壓檢出器 (601)減法器 (602)比例積分控制器 (604)加法器 (605)第一電壓檢出器 (606)波形產生器 (607)乘法器 (608)電流檢出器 (609)減法器 (610)誤差放大器 (611)驅動電路[Main component symbol description] (10) Mains power supply (11) Mains power supply voltage (1 2) Mains current (20) Decentralized power generation system (21) DC power (22) Current-controlled power converter (23) DC bus Voltage (30) load (40) first electromagnetic switch (50) second electromagnetic switch (600) second voltage detector (601) subtractor (602) proportional integral controller (604) adder (605) first Voltage Detector (606) Waveform Generator (607) Multiplier (608) Current Detector (609) Subtractor (610) Error Amplifier (611) Drive Circuit
[S1 14[S1 14