TWI597424B - Control method of screw pump and control system using the same - Google Patents
Control method of screw pump and control system using the same Download PDFInfo
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- TWI597424B TWI597424B TW104111502A TW104111502A TWI597424B TW I597424 B TWI597424 B TW I597424B TW 104111502 A TW104111502 A TW 104111502A TW 104111502 A TW104111502 A TW 104111502A TW I597424 B TWI597424 B TW I597424B
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Description
本案係關於一種控制方法，尤指一種螺桿泵的控制方法及其適用之控制系統。 This case relates to a control method, especially a control method of a screw pump and a control system thereof.
螺桿泵(screw pumps或progressive cavity pumps)常用於石化工業中，以從油井中抽吸石油。一般而言，螺桿泵的運作係由一控制系統控制，其中控制系統包含一電動馬達及一馬達驅動器，而螺桿泵則包含具有一轉子及一定子之一泵桿，螺桿泵之泵桿實體上係位於油井的深處，以抽吸石油至表面，轉子與定子之組合所形成的幾何形狀則構成兩個或更多組螺旋形而獨立的腔體。當轉子在定子內轉動時，腔體係由定子之一端以螺旋狀方式移動至另一端而建立正位移(正轉)的抽吸作動，藉此將石油吸出至表面。 Screw pumps or progressive cavity pumps are commonly used in the petrochemical industry to draw oil from oil wells. In general, the operation of the screw pump is controlled by a control system, wherein the control system comprises an electric motor and a motor drive, and the screw pump comprises a pump rod having a rotor and a stator, the pump rod of the screw pump is physically It is located deep in the well to draw oil to the surface, and the geometry formed by the combination of the rotor and the stator constitutes two or more sets of spiral and independent cavities. As the rotor rotates within the stator, the cavity system moves from one end of the stator in a helical manner to the other end to establish a positive displacement (forward rotation) suction action whereby oil is drawn to the surface.
當螺桿泵正轉而進行正常的抽吸運作時，由電動馬達所驅動之螺桿泵將提供電能而捲取泵桿，以將石油吸出至表面。然而當瞬間的電力中斷使螺桿泵的抽吸作動為反轉時便遭遇到許多顯著的問題，亦即當電力失效時，螺桿泵將因乘載於泵桿上之石油而失去控制儲存於泵桿之電能的能力，然而在螺桿泵之泵桿上仍存在龐 大的儲存能量，使得螺桿泵類似於捲繞的螺旋彈簧，故儲存能量將藉由螺桿泵之泵桿反向轉動而釋放，並使得螺桿泵之轉子改為轉向相反的方向，而螺桿泵的泵桿亦將旋轉於相反的方向，直到所有的石油已經下降至一生產管內，且因為重力因素，最後在生產管中的石油液面的高度將與在油井中的石油液面的高度相等。而螺桿泵反轉的時間可以持續幾個小時，端看螺桿泵的具體應用。在前述情況下，當電力恢復而再次供應時，螺桿泵的抽吸作動並不能立即重新啟動，因此在反轉的過程以及等待石油重新再被抽吸至地表所花費的時間皆失去生產力，故電力中斷或遺失便造成螺桿泵的生產力顯著的降低。 When the screw pump is rotating forward for normal suction operation, the screw pump driven by the electric motor will supply electrical energy to take up the pump rod to draw the oil out to the surface. However, when the instantaneous power interruption causes the pumping action of the screw pump to reverse, many significant problems are encountered. That is, when the power fails, the screw pump will be out of control and stored in the pump due to the oil loaded on the pump rod. The ability of the rod's electrical energy, however, still exists on the pump rod of the screw pump The large storage energy makes the screw pump similar to the coiled coil spring, so the stored energy will be released by the reverse rotation of the pump rod of the screw pump, and the rotor of the screw pump will be turned to the opposite direction, and the screw pump The pump rod will also rotate in the opposite direction until all the oil has fallen into a production tube, and because of gravity, the height of the oil level in the production tube will be equal to the height of the oil level in the well. . The reversal time of the screw pump can last for several hours, depending on the specific application of the screw pump. In the foregoing case, when the power is restored and supplied again, the pumping action of the screw pump cannot be immediately restarted, so the productivity in the process of reversing and waiting for the oil to be sucked back to the surface again loses productivity. Power interruption or loss results in a significant reduction in the productivity of the screw pump.
此外，當馬達驅動器被使用者關閉時，螺桿泵的抽吸作動速度將減緩，並進而根據預定的關閉排程而被一煞車裝置中止，當馬達驅動器停止提供驅動電壓至電動馬達而使電動馬達被關閉時，所儲存的能量將藉由螺桿泵的泵桿以高速反轉而被釋放，且因電動馬達的驅動機制通常與螺桿泵的轉子直接電連接，故電動馬達亦將被驅動而反轉，然不受控制之反轉將嚴重破壞電動馬達的驅動機制及其它生產設備，例如反轉可能導致設備損壞。再者，若此損壞發生在油井的地平面，將可能造成工作人員受傷及環境污染。 In addition, when the motor driver is closed by the user, the pumping speed of the screw pump will be slowed down, and then stopped by a braking device according to the predetermined closing schedule, when the motor driver stops supplying the driving voltage to the electric motor and the electric motor When it is turned off, the stored energy will be released by the pump rod of the screw pump at high speed reversal, and since the driving mechanism of the electric motor is usually directly connected to the rotor of the screw pump, the electric motor will also be driven and reversed. Turn, however, the uncontrolled reversal will seriously damage the drive mechanism of the electric motor and other production equipment, such as reversal may cause equipment damage. Furthermore, if this damage occurs at the ground level of the well, it may cause injury to workers and environmental pollution.
因此，如何發展一種可在電力失效時，控制螺桿泵的抽吸作動而消除反轉所具有的影響，進而改善上述習知技術缺失之螺桿泵的控制方法及其適用之控制系統，實為相關技術領域者目前所迫切需要解決之問題。 Therefore, how to develop a control method for a screw pump that can control the suction action of the screw pump to eliminate the influence of the reversal when the power fails, thereby improving the above-mentioned conventional technology, and the applicable control system are related. There is an urgent need for the technical field to solve the problem.
本案之目的在於提供一種螺桿泵的控制方法及其適用之控制系統，其係可在電力失效時，藉由使用由螺桿泵上之儲存位能所轉換之發電電能而維持馬達驅動器及電動馬達之作動，以進行螺桿泵之反轉控制，且可利用煞車裝置之煞車單元及煞車電阻將螺桿泵在進行反轉時所產生之多餘的儲存位能消耗掉，進而縮短螺桿泵的煞車時間，俾解決傳統控制系統在電能中斷而導致螺桿泵進行反轉時所具有的電動馬達的驅動機制或設備等容易損壞、工作人員的安全性不佳，環境汙染以及螺桿泵的生產力顯著降低等缺失。 The purpose of the present invention is to provide a control method of a screw pump and a control system therefor, which can maintain the motor driver and the electric motor by using the generated electric energy converted by the storage potential energy of the screw pump in the event of power failure. Actuated to perform the reversal control of the screw pump, and the brake unit and the brake resistor of the brake device can be used to consume the excess storage position generated when the screw pump is reversed, thereby shortening the brake time of the screw pump. The utility model solves the problem that the driving mechanism or equipment of the electric motor which is caused by the interruption of the electric power in the conventional control system is easily damaged, the safety of the worker is not good, the environmental pollution and the productivity of the screw pump are significantly reduced.
為達上述目的，本案之一較廣義實施態樣為提供一種控制方法，係應用控制系統，其中控制系統係用以控制螺桿泵之運作，且具有與螺桿泵同步轉動之電動馬達及用來控制電動馬達運作之馬達驅動器，馬達驅動器具有直流/交流轉換器，直流/交流轉換器係接收由電源提供之電力所產生之直流匯流排電壓，並將直流匯流排電壓進行轉換，以提供給電動馬達，控制方法係包含步驟如下：(a)監控直流匯流排電壓；(b)偵測直流匯流排電壓是否小於第一門檻值，並於偵測結果為是時執行步驟(c)；(c)將螺桿泵因進行反轉運作所釋放的儲存位能轉換為發電電能，並提供給馬達驅動器，使馬達驅動器維持作動；(d)由馬達驅動器驅動電動馬達根據反轉轉矩限制策略而控制螺桿泵之反轉運作；(e)限制直流匯流排電壓大於第二門檻值；(f)偵測電力是否恢復；(g)當步驟(f)的偵測結果為否時，監控反向發電轉矩之等級；(h)偵測反向發電轉矩之等級是否小於預設轉矩值；以及(i)當步驟(h)的偵測結果為是時，允許螺桿泵之反轉運作以自然地方式停止。 In order to achieve the above object, one of the more broad aspects of the present invention provides a control method, which is an application control system, wherein the control system is used to control the operation of the screw pump, and has an electric motor that rotates synchronously with the screw pump and is used for control. A motor driver for operating an electric motor, the motor driver having a DC/AC converter, the DC/AC converter receiving a DC bus voltage generated by the power supplied by the power source, and converting the DC bus voltage to the electric motor The control method includes the following steps: (a) monitoring the DC bus voltage; (b) detecting whether the DC bus voltage is less than the first threshold, and performing step (c) when the detection result is yes; (c) The storage position energy released by the screw pump due to the reverse operation is converted into power generation and supplied to the motor driver to maintain the motor driver; (d) the motor driver drives the electric motor to control the screw according to the reverse torque limiting strategy The reverse operation of the pump; (e) limiting the DC bus voltage to be greater than the second threshold; (f) detecting whether the power is restored; (g) when step (f) When the measurement result is no, monitor the level of the reverse power generation torque; (h) detect whether the level of the reverse power generation torque is less than the preset torque value; and (i) when the detection result of the step (h) is At this time, the reverse operation of the screw pump is allowed to stop in a natural manner.
為達上述目的，本案之另一較廣義實施態樣為提供一種控制系統，係用以控制螺桿泵之運作，且包含：電動馬達，係與該螺桿泵進行同步轉動；以及馬達驅動器，係與電源及電動馬達電連接，用以將電源所提供之電力進行轉換，以提供給電動馬達，其中馬達驅動器係包含：直流/交流轉換器，係與電動馬達電連接，用以接收由電源提供之電力所產生之直流匯流排電壓，並將直流匯流排電壓進行轉換，以提供給電動馬達；以及控制器，係與直流/交流轉換器電連接，用以控制直流/交流轉換器之運作，且監控直流匯流排電壓；其中當電源所提供之電力中斷而螺桿泵進行反轉運作，使控制器偵測到直流匯流排電壓小於第一門檻值時，馬達驅動器係使用由螺桿泵釋放的儲存位能所轉換的發電電能來進行運作，並根據反轉轉矩限制策略而控制螺桿泵之反轉運作。 In order to achieve the above object, another broad aspect of the present invention provides a control system for controlling the operation of a screw pump, and includes: an electric motor that rotates synchronously with the screw pump; and a motor driver The power source and the electric motor are electrically connected to convert the power provided by the power source to be supplied to the electric motor, wherein the motor driver comprises: a DC/AC converter electrically connected to the electric motor for receiving the power supply. a DC bus voltage generated by the power, and converting the DC bus voltage to the electric motor; and a controller electrically connected to the DC/AC converter to control the operation of the DC/AC converter, and Monitoring the DC bus voltage; wherein when the power provided by the power supply is interrupted and the screw pump is reversed, so that the controller detects that the DC bus voltage is less than the first threshold, the motor driver uses the storage position released by the screw pump The converted generated electric energy can be operated, and the reverse operation of the screw pump is controlled according to the reverse torque limiting strategy
1‧‧‧控制系統 1‧‧‧Control system
11‧‧‧電動馬達 11‧‧‧Electric motor
12‧‧‧馬達驅動器 12‧‧‧Motor drive
121‧‧‧交流/直流轉換器 121‧‧‧AC/DC converter
122‧‧‧直流鏈 122‧‧‧DC chain
123‧‧‧直流/交流轉換器 123‧‧‧DC/AC converter
124‧‧‧控制器 124‧‧‧ Controller
2‧‧‧螺桿泵 2‧‧‧ screw pump
3‧‧‧電源 3‧‧‧Power supply
Vbus‧‧‧直流匯流排電壓 V bus ‧‧‧DC bus voltage
1241‧‧‧速度估測器 1241‧‧‧Speed Estimator
1242‧‧‧反轉轉矩限制單元 1242‧‧‧Reverse torque limiting unit
1243‧‧‧速度控制電路 1243‧‧‧Speed Control Circuit
1244‧‧‧電流控制電路 1244‧‧‧ Current Control Circuit
1245‧‧‧脈衝寬度調變產生器 1245‧‧‧ pulse width modulation generator
1246‧‧‧轉矩控制器 1246‧‧‧ Torque controller
1247‧‧‧磁通量控制器 1247‧‧‧Magnetic flux controller
W^r‧‧‧轉動速度估測值 W^ r ‧‧‧ rotational speed estimate
T*e_backspin_limit‧‧‧轉矩限制 T* e_backspin_limit ‧‧‧ Torque limit
T*e‧‧‧轉矩指令 T* e ‧‧‧Torque Command
I*q‧‧‧Q軸座標電流指令 I* q ‧‧‧Q-axis coordinate current command
I*d‧‧‧D軸座標電流指令 I* d ‧‧‧D-axis coordinate current command
u* α ‧‧‧α電流指令 u* α ‧‧‧ α current command
u* β ‧‧‧β電流指令 u* β ‧‧‧ β current command
S11~S20‧‧‧本案之控制方法的步驟流程 Step procedure of S11~S20‧‧‧ control method of this case
S141~S143‧‧‧反轉轉矩限制策略的步驟流程 S141~S143‧‧‧Step flow of reverse torque limiting strategy
S161~S163‧‧‧子步驟 S161~S163‧‧‧ substeps
第1圖係為本案較佳實施例之控制系統的結構示意圖。 Figure 1 is a block diagram showing the structure of a control system of the preferred embodiment of the present invention.
第2圖係為第1圖所示之控制系統的電路方塊示意圖。 Figure 2 is a block diagram of the circuit of the control system shown in Figure 1.
第3A、3B圖係為本案較佳實施例之控制方法的步驟流程圖。 3A and 3B are flowcharts showing the steps of the control method of the preferred embodiment of the present invention.
第4圖係為第3A圖所示之步驟S14中之反轉轉矩限制策略的步驟流程圖。 Fig. 4 is a flow chart showing the steps of the reverse torque limiting strategy in step S14 shown in Fig. 3A.
第5圖係為第3B圖所示之步驟S16的子步驟的步驟流程圖。 Figure 5 is a flow chart showing the steps of the sub-steps of step S16 shown in Figure 3B.
第6圖係為本案之控制方法應用於第2圖所示之控制系統時，交流電壓、直流匯流排電壓、電動馬達之轉速以及反轉狀態的波形時序圖。 Fig. 6 is a waveform timing chart of the AC voltage, the DC bus voltage, the rotational speed of the electric motor, and the reverse state when the control method of the present invention is applied to the control system shown in Fig. 2.
第7圖係為本案之控制方法應用於第2圖所示之控制系統時，反轉狀態、電動轉矩限制及發電轉矩限制的波形時序圖。 Fig. 7 is a waveform timing chart of the reverse state, the electric torque limit, and the power generation torque limit when the control method of the present invention is applied to the control system shown in Fig. 2.
體現本案特徵與優點的一些典型實施例將在後段的說明中詳細敘述。應理解的是本案能夠在不同的態樣上具有各種的變化，其皆不脫離本案的範圍，且其中的說明及圖示在本質上係當作說明之用，而非架構於限制本案。 Some exemplary embodiments embodying the features and advantages of the present invention are described in detail in the following description. It is to be understood that the present invention is capable of various modifications in various aspects, and is not to be construed as a limitation.
請參閱第1圖及第2圖，其中第1圖係為本案較佳實施例之控制系統的結構示意圖，第2圖係為第1圖所示之控制系統的電路方塊示意圖。如第1圖及第2圖所示，本實施例之控制系統1係架構於控制及驅動一螺桿泵2之抽吸作動，以將油井中之石油抽吸至地表，其中螺桿泵2之構造係為習知技術，故在此不多贅述。控制系統1主要結構係包含一電動馬達11、一馬達驅動器12及一煞車裝置。電動馬達11係與螺桿泵2之泵桿之轉子電連接，架構於與螺桿泵2同步轉動，進而帶動螺桿泵2之泵桿之轉子轉動而將石油從油井抽吸至地表，且電動馬達11較佳可為感應馬達。煞車裝置係由一煞車單元5及一煞車電阻6所構成，其中煞車單元5電連接於馬達驅動器12及煞車電阻6之間，用以控制煞車電阻6之作動，使煞車電阻6釋放或消耗能量。 Please refer to FIG. 1 and FIG. 2 , wherein FIG. 1 is a schematic structural diagram of a control system according to a preferred embodiment of the present invention, and FIG. 2 is a circuit block diagram of the control system shown in FIG. 1 . As shown in FIG. 1 and FIG. 2, the control system 1 of the present embodiment is configured to control and drive the suction operation of a screw pump 2 to pump oil in the oil well to the surface, wherein the construction of the screw pump 2 It is a well-known technology, so I won't go into details here. The main structure of the control system 1 includes an electric motor 11, a motor driver 12, and a brake device. The electric motor 11 is electrically connected to the rotor of the pump rod of the screw pump 2, and is configured to rotate synchronously with the screw pump 2, thereby driving the rotor of the pump rod of the screw pump 2 to rotate and pumping oil from the oil well to the surface, and the electric motor 11 Preferably, it can be an induction motor. The brake device is composed of a brake unit 5 and a brake resistor 6. The brake unit 5 is electrically connected between the motor driver 12 and the brake resistor 6 for controlling the brake resistor 6 to release or consume the brake resistor 6. .
馬達驅動器12係與一電源3(例如三相電源)及電動馬達11電連接，用以控制電動馬達11之運作，且可包含一交流/直流轉換器121、一直流鏈122(例如直流匯流排)、一直流/交流轉換器123及一控制器124，但並不以此為限。交流/直流轉換器121可為但不限於由具有複數個二極體的三相整流器所構成，且交流/ 直流轉換器121之一輸入端係與電源3電連接，交流/直流轉換器121係從電源3接收電力，例如交流電壓(三相交流電壓)，並將交流電壓轉換為直流電壓。直流鏈122可由一電容所構成，其係電連接於交流/直流轉換器121之一輸出端，用以將交流/直流轉換器121所輸出之直流電壓穩壓濾波，以產生一直流匯流排電壓V bus。直流/交流轉換器123可為但不限於由具有一個或複數個絕緣閘雙極性電晶體(IGBTs)之三相逆變器所構成，且直流/交流轉換器123係與直流鏈122及電動馬達11電連接，用以接收直流匯流排電壓V bus，並轉換為一驅動電壓，以驅動並控制電動馬達11之運作。控制器124可為但不限於為信號處理器(DSP)，且與直流/交流轉換器123及直流鏈122電連接，用以控制直流/交流轉換器123之絕緣閘雙極性電晶體的作動，並可監控直流匯流排電壓V bus。在其它實施例中，馬達驅動器12係利用脈衝寬度調變(PWM)技術改變直流/交流轉換器123所輸出之驅動電壓的頻率及振幅，藉此控制電動馬達11之轉動速度，當驅動電壓的頻率增加時，電動馬達11係加速轉動，同時，電源3之電力將透過馬達驅動器12傳輸至電動馬達11，以提供驅動電動馬達11所需之能量。馬達驅動器12較佳可為變頻驅動器或變速驅動器，其係藉由改變電動馬達11所接收之驅動電壓的頻率及振幅來控制電動馬達11的速度及轉矩。 The motor driver 12 is electrically connected to a power source 3 (for example, a three-phase power source) and an electric motor 11 for controlling the operation of the electric motor 11, and may include an AC/DC converter 121 and a DC link 122 (for example, a DC bus bar). ), the DC/AC converter 123 and a controller 124 are not limited thereto. The AC/DC converter 121 can be, but is not limited to, a three-phase rectifier having a plurality of diodes, and AC/ One of the input terminals of the DC converter 121 is electrically connected to the power source 3, and the AC/DC converter 121 receives power from the power source 3, such as an AC voltage (three-phase AC voltage), and converts the AC voltage into a DC voltage. The DC link 122 can be formed by a capacitor electrically connected to an output end of the AC/DC converter 121 for voltage-stabilizing and filtering the DC voltage outputted by the AC/DC converter 121 to generate a DC bus voltage. V bus. The DC/AC converter 123 can be, but is not limited to, a three-phase inverter having one or a plurality of insulated gate bipolar transistors (IGBTs), and the DC/AC converter 123 is coupled to the DC link 122 and the electric motor. 11 is electrically connected to receive the DC bus voltage Vbus and converted into a driving voltage to drive and control the operation of the electric motor 11. The controller 124 can be, but is not limited to, a signal processor (DSP), and is electrically connected to the DC/AC converter 123 and the DC link 122 for controlling the operation of the insulated gate bipolar transistor of the DC/AC converter 123. The DC bus voltage V bus can be monitored. In other embodiments, the motor driver 12 uses a pulse width modulation (PWM) technique to change the frequency and amplitude of the driving voltage output by the DC/AC converter 123, thereby controlling the rotational speed of the electric motor 11, when driving the voltage. When the frequency is increased, the electric motor 11 is accelerated to rotate, and at the same time, the power of the power source 3 is transmitted to the electric motor 11 through the motor driver 12 to provide the energy required to drive the electric motor 11. The motor driver 12 is preferably a variable frequency drive or a variable speed drive that controls the speed and torque of the electric motor 11 by varying the frequency and amplitude of the drive voltage received by the electric motor 11.
於本實施例中，控制器124係包含一速度估測器1241、一反轉轉矩限制單元1242、一速度控制電路(ASR)1243、一電流控制電路(ACR)1244、一脈衝寬度調變產生器1245、一轉矩控制器1246及一磁通量控制器1247，其中速度控制電路1243、電流控制 電路1244、脈衝寬度調變產生器1245、轉矩控制器1246及磁通量控制器1247之結構及作動方式係為習知技術，故於此不再贅述。於本實施例中，速度估測器1241係與電動馬達11電連接，用以估測電動馬達11之轉子的轉動速度而輸出一轉動速度估測值W^ r。反轉轉矩限制單元1242架構於儲存一反轉轉矩限制策略，並與速度估測器1241電連接，以根據來自於速度估測器1241之轉動速度估測值W^r而提供一轉矩限制T* e_backspin_limit。速度控制電路1243係與反轉轉矩限制單元1242電連接，架構於接收一馬達轉動速度指令W* r及來自反轉轉矩限制單元124之轉矩限制T* e_backspin_limit，並根據馬達轉動速度指令W*r及轉矩限制T* e_backspin_limit而提供一轉矩指令T* e。轉矩控制器1246係與速度控制電路1243電連接，架構於接收轉矩指令T* e，並轉換轉矩指令T* e為一Q軸座標電流指令I* q。磁通量控制器1247架構於產生一D軸座標電流指令I* d。電流控制電路1244係與轉矩控制器1246及磁通量控制器1247電連接，架構於根據轉矩控制器1246之Q軸座標電流指令I* q及磁通量控制器1247之D軸座標電流指令I* d而分別產生一α電流指令u* α及一β電流指令u* β。脈衝寬度調變產生器1245係與電流控制電路1244及交流/直流轉換器123電連接，架構於根據電流控制電路1244所輸出之α電流指令u* α及β電流指令u* β而產生一脈衝寬度調變信號，藉此控制交流/直流轉換器123之開關元件(例如絕緣閘雙極性電晶體)的導通或截止的切換作動，進而驅動及控制電動馬達11之作動，並消除電動馬達11在反轉時所造成的影響。 In this embodiment, the controller 124 includes a speed estimator 1241, a reverse torque limiting unit 1242, a speed control circuit (ASR) 1243, a current control circuit (ACR) 1244, and a pulse width modulation. The generator 1245, a torque controller 1246 and a magnetic flux controller 1247, wherein the speed control circuit 1243, the current control circuit 1244, the pulse width modulation generator 1245, the torque controller 1246, and the magnetic flux controller 1247 are configured and actuated The method is a conventional technique, and thus will not be described again. In the present embodiment, the speed estimator 1241 is electrically connected to the electric motor 11 for estimating the rotational speed of the rotor of the electric motor 11 and outputting a rotational speed estimated value W^r. The reverse torque limiting unit 1242 is configured to store a reverse torque limiting strategy and is electrically coupled to the speed estimator 1241 to provide a turn based on the rotational speed estimate W^r from the speed estimator 1241. The moment limits T* e_backspin_limit. The speed control circuit 1243 is electrically connected to the reverse torque limiting unit 1242, and is configured to receive a motor rotational speed command W*r and a torque limit T*e_backspin_limit from the reverse torque limiting unit 124, and according to the motor rotational speed command. W*r and torque limit T* e_backspin_limit provide a torque command T* e. The torque controller 1246 is electrically coupled to the speed control circuit 1243, is configured to receive the torque command T*e, and convert the torque command T*e to a Q-axis coordinate current command I*q. The flux controller 1247 is configured to generate a D-axis coordinate current command I*d. The current control circuit 1244 is electrically connected to the torque controller 1246 and the magnetic flux controller 1247, and is configured according to the Q-axis coordinate current command I* q of the torque controller 1246 and the D-axis coordinate current command I* d of the magnetic flux controller 1247. An α current command u* α and a β current command u* β are respectively generated. The pulse width modulation generator 1245 is electrically connected to the current control circuit 1244 and the AC/DC converter 123, and is configured to generate a pulse according to the α current command u* α and the β current command u* β output by the current control circuit 1244. The width modulation signal, thereby controlling the switching operation of the switching element (for example, the insulating gate bipolar transistor) of the AC/DC converter 123, thereby driving and controlling the operation of the electric motor 11, and eliminating the electric motor 11 The effect of reversing.
而於本實施例中，當控制系統1控制電動馬達11正轉而使螺桿泵2 正轉，以進行正常的抽吸作動時，螺桿泵2之泵桿將被電動馬達11驅動而將石油從油井抽吸至地表，此時螺桿泵2係因泵桿上之石油係逐漸上升至地表而儲存對應的位能(以下稱為儲存位能)。 In the present embodiment, when the control system 1 controls the electric motor 11 to rotate forward, the screw pump 2 is When the normal rotation is performed for the normal suction operation, the pump rod of the screw pump 2 will be driven by the electric motor 11 to suck the oil from the oil well to the surface, and the screw pump 2 is gradually raised to the petroleum system on the pump rod to The corresponding bit energy (hereinafter referred to as the storage bit energy) is stored on the surface.
請參閱第3A、3B圖並配合第6圖及第7圖，其中第3A、3B圖係為本案較佳實施例之控制方法的步驟流程圖，第6圖係為本案之控制方法應用於第2圖所示之控制系統時，交流電壓、直流匯流排電壓、電動馬達之轉速以及反轉狀態的波形時序圖，第7圖係為本案之控制方法應用於第2圖所示之控制系統時，反轉狀態、電動轉矩限制及發電轉矩限制的波形時序圖。如第3A、3B圖、第6圖、第7圖所示，本案之控制方法可應用於第2圖所示之控制系統1之控制器124中，且包含以下步驟：首先，馬達驅動器12之控制器124監控直流匯流排電壓V bus(請參閱步驟S11)。接著，控制器124偵測直流匯流排電壓V bus是否小於一第一門檻值(請參閱步驟S12)。當控制器124偵測到直流匯流排電壓V bus大於或等於第一門檻值時，螺桿泵2之泵桿將持續被電動馬達11驅動，且螺桿泵2係處於正向轉動運作而正常抽吸油井中之石油，在此情況下，將再次執行步驟S11，控制器124便持續監控直流匯流排電壓V bus。反之，當步驟S12中控制器124偵測到直流匯流排電壓V bus小於第一門檻值時，控制器124便判定電源3用來使直流鏈122產生直流匯流排電壓V bus而提供的交流電壓因發生電力中斷(例如跳電而交流電壓為零)或因馬達驅動器12回應指令而關閉而正在減少，此時便執行步驟S13。在步驟S13中，因電力中斷而直流匯流排電壓V bus小於第一門檻值時，螺桿泵2之泵桿將因螺桿泵2上之石油受重力影響而由正轉逐漸切換至反轉， 而螺桿泵2上之石油所具有的儲存位能便藉由泵桿之反轉作用而釋放並進一步轉換為發電電能，以供給馬達驅動器12，以維持馬達驅動器12及電動馬達11之作動，亦即當電源3所提供之電力失去或當馬達驅動器12因回應指令而關閉時，控制系統1可藉由重新產生之發電電能(即由儲存位能轉換後所產生之發電電能)而維持馬達驅動器12及電動馬達11之作動，進而控制螺桿泵2之反轉運作，直到螺桿泵2上所有的石油皆已經下降至一生產管內，而生產管內的石油液面的高度亦和油井的石油液面的高度相等。 Please refer to FIGS. 3A and 3B and cooperate with FIG. 6 and FIG. 7 , wherein FIGS. 3A and 3B are flowcharts of steps of the control method of the preferred embodiment of the present invention, and FIG. 6 is a control method applied to the present application. In the control system shown in Fig. 2, the waveform timing diagram of the AC voltage, the DC bus voltage, the rotational speed of the electric motor, and the reverse state, Fig. 7 is the control method of the present case applied to the control system shown in Fig. 2. Waveform timing diagram for reverse state, electric torque limit, and power generation torque limit. As shown in FIGS. 3A, 3B, 6 and 7, the control method of the present invention can be applied to the controller 124 of the control system 1 shown in FIG. 2, and includes the following steps: First, the motor driver 12 The controller 124 monitors the DC bus voltage V bus (refer to step S11). Next, the controller 124 detects whether the DC bus voltage V bus is less than a first threshold (refer to step S12). When the controller 124 detects that the DC bus voltage V bus is greater than or equal to the first threshold, the pump rod of the screw pump 2 will continue to be driven by the electric motor 11, and the screw pump 2 is in the forward rotation operation and is normally sucked. The oil in the oil well, in this case, will perform step S11 again, and the controller 124 continuously monitors the DC bus voltage V bus . On the contrary, when the controller 124 detects that the DC bus voltage V bus is less than the first threshold in step S12, the controller 124 determines the AC voltage that the power source 3 uses to generate the DC bus voltage V bus from the DC link 122. Since the power interruption (for example, the AC voltage is zero due to the power jump) or the motor driver 12 is turned off in response to the command, the step S13 is executed. In step S13, when the DC bus voltage V bus is less than the first threshold due to power interruption, the pump rod of the screw pump 2 will gradually switch from forward to reverse due to the influence of gravity on the oil on the screw pump 2. The storage position of the oil on the screw pump 2 is released by the reverse action of the pump rod and further converted into electric power for power supply to the motor driver 12 to maintain the operation of the motor driver 12 and the electric motor 11. That is, when the power provided by the power source 3 is lost or when the motor driver 12 is turned off by responding to the command, the control system 1 can maintain the motor driver by regenerating the generated power (ie, the generated power generated by the storage bit energy conversion). 12 and the operation of the electric motor 11 to control the reverse operation of the screw pump 2 until all the oil on the screw pump 2 has been lowered into a production pipe, and the height of the oil level in the production pipe is also the oil of the oil well. The height of the liquid surface is equal.
當執行完步驟S13後，馬達驅動器12便驅動電動馬達11根據一反轉轉矩限制策略而控制螺桿泵2之反轉運作(即螺桿泵2由正轉逐漸變為反轉的運作過程)，例如螺桿泵2反轉時的轉速等(請參閱步驟S14)。再請參閱第4圖，其係為第3A圖所示之步驟S14中之反轉轉矩限制策略的步驟流程圖。如第4圖所示，在步驟S14的反轉轉矩限制策略中，首先設定馬達轉動速度指令W* r為負，而當電動馬達11之轉動速度被速度估測器1241評估為正時，便將一正向電動轉矩限制(Torque limit_motor)設定為零，藉此不驅動電動馬達11朝正向轉動，且將一正向發電轉矩限制(Torque limit_generative)設定為一正常操作值，該正常操作值可為一額定轉矩的倍數(例如120)，藉此在螺桿泵2仍正向轉動的過程中(螺桿泵2正向轉動的轉速逐漸降低)將螺桿泵2所釋放之儲存位能轉換為發電電能(請參閱步驟S141)，在此情況下，發電電能被傳輸至馬達驅動器12之直流鏈122，且由馬達驅動器12所輸出之能量(例如驅動電壓)亦縮減。當電動馬達11之轉動速度被速度估測器1241評估為負且低於一預定值時(即代表電動馬達11已為 反轉狀態但轉速尚未到達預定值)，將一反向電動轉矩限制設定為零，藉此不強迫驅動電動馬達11朝反向轉動，而是使電動馬達11因螺桿泵2上之石油受到重力影響而自然地反轉，且將一反向發電轉矩限制設定為該正常操作值，該正常操作值可為額定轉矩的倍數(例如120)，藉此在螺桿泵2為反向轉動的過程中(螺桿泵2反向轉動的轉速逐漸提升)將螺桿泵2上之儲存位能轉換為發電電能(請參閱步驟S142)。當電動馬達11之轉動速度被速度估測器1241評估為負且大於或等於該預定值時，便執行一反轉速度控制模式，在此情況下，反向電動轉矩限制及反向發電轉矩限制皆設定為該正常操作值(例如120)，藉此控制電動馬達11在反向轉動時之速度，例如維持在預定值，同時亦將螺桿泵2上之儲存位能轉換為發電電能(請參閱步驟S143)。 When step S13 is performed, the motor driver 12 drives the electric motor 11 to control the reverse operation of the screw pump 2 according to a reverse torque limiting strategy (ie, the operation of the screw pump 2 from forward rotation to reverse rotation), For example, the number of revolutions when the screw pump 2 is reversed, etc. (refer to step S14). Referring again to FIG. 4, it is a flow chart of the steps of the reverse torque limiting strategy in step S14 shown in FIG. 3A. As shown in FIG. 4, in the reverse torque limiting strategy of step S14, first, the motor rotational speed command W*r is set to be negative, and when the rotational speed of the electric motor 11 is evaluated as positive by the speed estimator 1241, A forward electric torque limit (Torque limit_motor) is set to zero, thereby not driving the electric motor 11 to rotate in the forward direction, and setting a forward power generation torque limit (Torque limit_generative) to a normal operation value, The normal operation value may be a multiple of a rated torque (for example, 120), whereby the storage position released by the screw pump 2 during the forward rotation of the screw pump 2 (the rotational speed of the forward rotation of the screw pump 2 is gradually decreased) It can be converted into power generation (refer to step S141), in which case the generated electric energy is transmitted to the DC link 122 of the motor driver 12, and the energy (for example, the driving voltage) output by the motor driver 12 is also reduced. When the rotational speed of the electric motor 11 is evaluated by the speed estimator 1241 to be negative and lower than a predetermined value (ie, the electric motor 11 has been The reverse state but the rotational speed has not yet reached the predetermined value), a reverse electric torque limit is set to zero, whereby the electric motor 11 is not forced to rotate in the reverse direction, but the electric motor 11 is subjected to the oil on the screw pump 2 Naturally reversed by the influence of gravity, and a reverse power generation torque limit is set to the normal operation value, which may be a multiple of the rated torque (for example, 120), whereby the screw pump 2 is reversely rotated. During the process (the rotational speed of the reverse rotation of the screw pump 2 is gradually increased), the storage potential energy on the screw pump 2 is converted into electric power generation (refer to step S142). When the rotational speed of the electric motor 11 is evaluated as negative by the speed estimator 1241 and greater than or equal to the predetermined value, a reverse speed control mode is executed, in which case the reverse electric torque limit and the reverse power generation turn The moment limit is set to the normal operation value (for example, 120), thereby controlling the speed of the electric motor 11 in the reverse rotation, for example, maintaining the predetermined value, and also converting the storage position energy on the screw pump 2 into the generated electric energy ( Please refer to step S143).
請再參閱第3A、3B圖，當執行完步驟S14後，係藉由煞車單元5及煞車電阻6釋放多餘的發電電能而限制直流匯流排電壓V bus大於一第二門檻值(請參閱步驟S15)，其中第二門檻值可為但不限於低於第一門檻值。當步驟S15執行完後，控制器124便偵測電源3所提供之電力是否恢復而再次供應(請參閱步驟S16)。 Please refer to FIG. 3A and FIG. 3B again. After the step S14 is performed, the DC bus voltage V bus is limited to be greater than a second threshold by releasing the excess power generated by the brake unit 5 and the braking resistor 6 (refer to step S15). And wherein the second threshold value may be, but is not limited to, lower than the first threshold value. When the step S15 is performed, the controller 124 detects whether the power supplied from the power source 3 is restored and supplies it again (refer to step S16).
而於步驟S16中，當控制器124在進行控制電動馬達11的反轉運作期間偵測到電源3所提供之電力已恢復而再次供應時，馬達驅動器12便驅動電動馬達11執行正向轉動並加快旋轉速度，以控制螺桿泵2立即由油井抽吸石油(請參閱步驟S17)，然後再次執行步驟S11。反之，於步驟S16中，當控制器124偵測電源3所提供之電力並無恢復而仍中斷時，便監控一之等級(請參閱步驟S18)。接著，將之等級與一預設轉矩值比對而偵測之等級是否小於預設轉矩 值(請參閱步驟S19)。在步驟S19中，當之等級係小於轉矩預設值時，便允許螺桿泵2之反轉係以自然地方式停止(請參閱步驟S20)。反之，在步驟S19中，當反向發電轉矩之等級係大於預設轉矩值時，便再次執行步驟S13。 In step S16, when the controller 124 detects that the power supplied by the power source 3 has been restored and is supplied again during the reverse operation of controlling the electric motor 11, the motor driver 12 drives the electric motor 11 to perform the forward rotation and The rotation speed is increased to control the screw pump 2 to immediately draw oil from the oil well (refer to step S17), and then step S11 is performed again. On the other hand, in step S16, when the controller 124 detects that the power supplied by the power source 3 has not recovered and is still interrupted, it monitors a level (refer to step S18). Then, comparing the level with a preset torque value and detecting whether the level is less than the preset torque Value (see step S19). In step S19, when the rank is less than the torque preset value, the reversal of the screw pump 2 is allowed to stop in a natural manner (see step S20). On the other hand, in step S19, when the level of the reverse power generation torque is greater than the preset torque value, step S13 is performed again.
請參閱第5圖，其係為第3B圖所示之步驟S16的子步驟的步驟流程圖。如第5圖所示，在步驟S16中，首先，當馬達驅動器12之控制器124偵測到電動馬達11執行反轉運作所經過的一時間區間係長於一第一預設時間時，係控制正向電動轉矩限制返回該正常操作值，該正常操作值可為額定轉矩的倍數(例如120)，並設定馬達轉動速度指令W* r為正值，藉此使馬達驅動器12操作於一正常正向運作模式而驅動電動馬達11由反正轉動改為正向轉動(請參閱步驟S161)。然而在步驟S161執行完後，若控制器124偵測到直流匯流排電壓V bc再次小於第一門檻值時，即代表電源3並無法提供電力而維持直流匯流排電壓V bc，控制器124便判斷電源3所提供之電力為未恢復狀態(請參閱步驟S162)。而當步驟S162判斷出電源3所提供之電力並未恢復且經過一第二預設時間時，控制器124便判斷電力係遺失很長一段時間而執行步驟S18(請參閱步驟S163)。 Please refer to FIG. 5, which is a flow chart of the steps of the sub-step of step S16 shown in FIG. 3B. As shown in FIG. 5, in step S16, first, when the controller 124 of the motor driver 12 detects that the time interval elapsed after the electric motor 11 performs the reverse operation is longer than a first preset time, the system controls The forward electric torque limit returns to the normal operating value, which may be a multiple of the rated torque (eg, 120), and sets the motor rotational speed command W* r to a positive value, thereby causing the motor driver 12 to operate at In the normal forward operation mode, the electric motor 11 is driven to change from the reverse rotation to the forward rotation (refer to step S161). However, after the step S161 is performed, if the controller 124 detects that the DC bus voltage V bc is less than the first threshold value, that is, the power source 3 cannot provide power and maintains the DC bus voltage V bc , the controller 124 It is judged that the power supplied from the power source 3 is in an unrecovered state (refer to step S162). When it is determined in step S162 that the power supplied by the power source 3 has not recovered and a second preset time has elapsed, the controller 124 determines that the power system is lost for a long period of time and performs step S18 (please refer to step S163).
綜上所述，本案提供一種螺桿泵的控制方法及其適用之控制系統，其係可控制螺桿泵的運作，以消除當電力遺失而進行反轉時的影響，亦即當本案之控制系統的馬達驅動器偵測到電力失效時，本案之控制系統可藉由使用由螺桿泵上之儲存位能所轉換之發電電能(其中當電力失效時，螺桿泵之泵桿便會因石油受重力影響而而釋放儲存位能，該儲存位能係在所有的石油皆已經下降至生 產管內，而生產管的石油液面高度亦和油井的石油液面高度相等時才為零，而發電電能便由轉換儲存位能而產生)而維持馬達驅動器及電動馬達之作動，以對螺桿泵之反轉運作進行控制，藉此避免電動馬達的相關驅動機制或設備損壞，同時提升工作人員的安全性。此外，當電動馬達及螺桿泵因電力失去而反轉時，煞車裝置之煞車單元及煞車電阻可將多餘的儲存位能轉呈熱能而消耗掉，故可縮短螺桿泵的煞車時間，如此一來，一旦電能再次供應時，本案之控制系統之馬達驅動器便可驅動電動馬達控制螺桿泵立即執行正向移位抽吸作動，故本案之螺桿泵的控制方法及其適用之控制系統可提升螺桿泵之生產力。 In summary, the present invention provides a control method of a screw pump and a control system therefor, which can control the operation of the screw pump to eliminate the influence when the power is reversed and reversed, that is, when the control system of the present case When the motor driver detects a power failure, the control system of the present case can generate electricity by using the storage potential energy of the screw pump (wherein, when the power fails, the pump rod of the screw pump is affected by the gravity of the oil) And the release of the storage capacity, the storage can be tied to all the oil has been reduced to the raw In the production pipe, the height of the oil level of the production pipe is equal to the height of the oil level of the oil well, and the power generation is generated by the conversion of the storage energy to maintain the operation of the motor driver and the electric motor. The reverse operation of the screw pump is controlled, thereby avoiding the relevant driving mechanism or equipment damage of the electric motor and improving the safety of the worker. In addition, when the electric motor and the screw pump are reversed due to the loss of power, the brake unit and the brake resistor of the brake device can dissipate excess storage energy into heat energy, thereby shortening the brake time of the screw pump, thus Once the electric energy is re-supplied, the motor driver of the control system of the present case can drive the electric motor to control the screw pump to immediately perform the positive displacement pumping operation. Therefore, the control method of the screw pump and the applicable control system thereof can improve the screw pump. Productivity.
本案得由熟習此技術之人士任施匠思而為諸般修飾，然皆不脫如附申請專利範圍所欲保護者。 This case has been modified by people who are familiar with the technology, but it is not intended to be protected by the scope of the patent application.
S11~S20‧‧‧本案之控制方法的步驟流程 Step procedure of S11~S20‧‧‧ control method of this case
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| CN112630538B (en) | 2019-09-24 | 2024-04-16 | 台达电子工业股份有限公司 | Method for estimating braking resistance |
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| CA2683339C (en) * | 2004-06-18 | 2010-08-17 | Unico, Inc. | Method and system for improving pump efficiency and productivity under power disturbance conditions |
| CN2919687Y (en) * | 2006-06-12 | 2007-07-04 | 大庆油田有限责任公司 | Electromagnetic brake device for preventing sucker rod of screw pump well from reversing |
| JP2008045497A (en) * | 2006-08-17 | 2008-02-28 | Heishin Engineering & Equipment Co Ltd | Drive method and device of uniaxial eccentric screw pump |
| TWI411219B (en) * | 2008-10-17 | 2013-10-01 | Foxnum Technology Co Ltd | Motor driver |
| CN102400912B (en) * | 2010-09-17 | 2014-12-24 | 深圳市汇川技术股份有限公司 | Shutdown braking system and method for screw pump |
| CN102953984B (en) * | 2012-12-05 | 2015-12-09 | 深圳市蓝海华腾技术股份有限公司 | A kind of controlling method of directly-driven screw pump soft stop and equipment |
| CN203035547U (en) * | 2013-02-05 | 2013-07-03 | 大庆市沛泽石油科技有限公司 | Remote digital control system of direct-drive screw pump |
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