TWI806784B - Power conversion circuit for driving motor and control method thereof - Google Patents
Power conversion circuit for driving motor and control method thereof Download PDFInfo
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本案係關於一種電源轉換電路及其控制方法,尤指一種用於驅動馬達的電源轉換電路及其控制方法。This case relates to a power conversion circuit and its control method, especially a power conversion circuit for driving a motor and its control method.
在由電池供電之馬達驅動應用中,DC bus (直流匯流排) 電容漣波由驅動器之開關組合所決定。在現有技術中,可透過重組PWM (pulse width modulation,脈衝寬度調變) 開關向量來降低漣波,然其計算方式複雜且不易實行。於另一做法中,係基於三角載波使用AZSVPWM (active zero state space vector pulse width modulation) 搭配零序注入,從而達到重新分配向量並最小化電容漣波之效果。然而,一般來說,微處理器中的PWM模組多不支援三角波之翻轉;此外,即便強行翻轉三角載波,亦無法產生上下臂開關所需的死區時間 (dead time)。為此,須在微處理器外部額外增設FPGA (field programmable gate array) 以進行特殊PWM處理,藉此翻轉載波並引入死區時間。再者,三角載波的翻轉過程中將產生額外的開關切換,在牽引 (traction) 電機應用中,高速情況下將導致開關的切換頻率上升。In battery-powered motor drive applications, the DC bus (direct current bus) capacitor ripple is determined by the drive's switching combination. In the prior art, the ripple can be reduced by reorganizing the PWM (pulse width modulation, pulse width modulation) switching vector, but the calculation method is complicated and difficult to implement. Another approach is to use AZSVPWM (active zero state space vector pulse width modulation) with zero-sequence injection based on the triangular carrier wave, so as to achieve the effect of redistributing vectors and minimizing capacitor ripple. However, generally speaking, the PWM modules in the microprocessor do not support the inversion of the triangular wave; in addition, even if the triangular carrier is forcibly inverted, the dead time required for switching the upper and lower arms cannot be generated. For this reason, an additional FPGA (field programmable gate array) must be added outside the microprocessor for special PWM processing, thereby inverting the carrier and introducing dead time. Furthermore, the inversion of the triangular carrier will generate additional switching, which will increase the switching frequency of the switches at high speeds in traction motor applications.
因此,如何發展一種可改善上述習知技術之用於驅動馬達的電源轉換電路及其控制方法,實為目前迫切之需求。Therefore, how to develop a power conversion circuit for driving a motor and a control method thereof that can improve the above-mentioned conventional technology is an urgent need at present.
本案之目的在於提供一種用於驅動馬達的電源轉換電路及其控制方法,其通過翻轉判斷邏輯而非載波來達到向量重新配置。藉此,可有效降低電容漣波,從而降低電容溫升以延長電容壽命,同時降低馬達之驅動耗損並提升驅動效率。再者,僅通過既有之控制器 (例如微處理器) 即可執行本案之控制方法而實現PWM調控,無須外加硬體 (例如FPGA) 進行PWM處理。The purpose of this case is to provide a power conversion circuit for driving a motor and its control method, which realizes vector reconfiguration by inverting judgment logic instead of carrier. In this way, the capacitor ripple can be effectively reduced, thereby reducing the temperature rise of the capacitor to prolong the life of the capacitor, while reducing the driving loss of the motor and improving the driving efficiency. Furthermore, the control method of this application can be implemented to realize PWM regulation only through an existing controller (such as a microprocessor), and no external hardware (such as FPGA) is required for PWM processing.
為達上述目的,本案提供一種用於電源轉換電路之控制方法,包括:比較三相控制命令與控制載波,取得脈寬調變訊號;提供脈寬調變訊號驅動電源轉換電路中的多個開關,讓多個開關切換輸入電源產生三相輸出電源;檢測三相輸出電源的電壓及電流之間的相位差是否落入預定相位範圍;如果檢測到相位差落入預定相位範圍,則依據三相輸出電源的電壓及電流決定零序電壓為正電壓或負電壓;對三相控制命令注入零序電壓來取得三相合成命令,並且在一時間週期後檢測三相合成命令中的最大電壓值及最小電壓值;依據零序電壓被決定為正電壓或負電壓,選擇最大電壓值或最小電壓值進行邏輯反相運算;完成邏輯反相運算並停止注入零序電壓後,取得三相輸出期望值;以及比較三相輸出期望值以及控制載波,來調節脈寬調變訊號的占空比。To achieve the above purpose, this project provides a control method for a power conversion circuit, including: comparing the three-phase control command and the control carrier to obtain a pulse width modulation signal; providing a pulse width modulation signal to drive multiple switches in the power conversion circuit , so that multiple switches switch the input power to generate a three-phase output power; detect whether the phase difference between the voltage and current of the three-phase output power falls within the predetermined phase range; if it is detected that the phase difference falls within the predetermined phase range, then according to the three-phase The voltage and current of the output power supply determine whether the zero-sequence voltage is positive or negative; inject zero-sequence voltage into the three-phase control command to obtain the three-phase composite command, and detect the maximum voltage value and The minimum voltage value; according to the zero-sequence voltage being determined as positive or negative voltage, select the maximum voltage value or the minimum voltage value for logic inversion operation; after completing the logic inversion operation and stopping the injection of zero-sequence voltage, the expected value of the three-phase output is obtained; And compare the expected value of the three-phase output and control the carrier to adjust the duty cycle of the PWM signal.
為達上述目的,本案另提供一種用於驅動馬達的電源轉換電路,包括多個開關組、直流排電容及控制器。每一開關組包括上橋電晶體和下橋電晶體,並且每一上橋電晶體的第一端彼此電連接,每一下橋電晶體的第二端彼此電連接。在每一開關組中,上橋電晶體之第二端電連接下橋電晶體之第一端。直流排電容用以接收輸入電源,其中直流排電容的第一端電連接每一上橋電晶體的第一端,且直流排電容的第二端電連接每一下橋電晶體的第二端。控制器比較三相控制命令以及控制載波,取得多個脈寬調變訊號。每一開關組對應地接收其中一個脈寬調變訊號,並且在每一開關組中,依據所對應接收的脈寬調變訊號,上橋電晶體選擇性地導通或截止,以及下橋電晶體選擇性地截止或導通,使得多個開關組切換輸入電源,產生三相輸出電源驅動馬達。如果控制器檢測三相輸出電源的電壓及電流之間的相位差沒有落入預定相位範圍,則控制器檢測三相控制命令中的最小控制電壓,控制器對最小控制電壓進行邏輯反相運算,取得三相輸出命令。控制器比較三相輸出命令以及控制載波,來調節每一脈寬調變訊號的占空比。In order to achieve the above purpose, the present application further provides a power conversion circuit for driving a motor, including a plurality of switch groups, DC row capacitors and a controller. Each switch group includes an upper-bridge transistor and a lower-bridge transistor, and the first ends of each upper-bridge transistor are electrically connected to each other, and the second ends of each lower-bridge transistor are electrically connected to each other. In each switch group, the second end of the upper bridge transistor is electrically connected to the first end of the lower bridge transistor. The DC row capacitor is used to receive input power, wherein the first end of the DC row capacitor is electrically connected to the first end of each high-bridge transistor, and the second end of the DC row capacitor is electrically connected to the second end of each low-bridge transistor. The controller compares the three-phase control command and the control carrier to obtain multiple pulse width modulation signals. Each switch group correspondingly receives one of the pulse width modulation signals, and in each switch group, according to the corresponding received pulse width modulation signal, the upper bridge transistor is selectively turned on or off, and the lower bridge transistor Selectively cut off or on, so that multiple switch groups switch the input power to generate three-phase output power to drive the motor. If the controller detects that the phase difference between the voltage and current of the three-phase output power supply does not fall within the predetermined phase range, the controller detects the minimum control voltage in the three-phase control command, and the controller performs a logic inversion operation on the minimum control voltage, Get the three-phase output command. The controller compares the three-phase output commands and controls the carrier to adjust the duty cycle of each PWM signal.
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,其皆不脫離本案之範圍,且其中的說明及圖示在本質上係當作說明之用,而非用以限制本案。Some typical embodiments embodying the features and advantages of the present application will be described in detail in the description in the following paragraphs. It should be understood that this case can have various changes in different aspects without departing from the scope of this case, and the descriptions and diagrams therein are used as illustrations in nature, not to limit this case.
第1圖為本案一實施例之電源轉換電路的電路結構示意圖。如第1圖所示,電源轉換電路1用於驅動馬達2,且電源轉換電路1包括多個開關組11 (第1圖中例示三個開關組11)、直流排電容Cdc及控制器12。每一開關組11包括上橋電晶體和下橋電晶體,並且每一上橋電晶體的第一端彼此電連接,每一下橋電晶體的第二端彼此電連接,其中在每一開關組11中,上橋電晶體之第二端電連接下橋電晶體之第一端。於第1圖所示實施例中,第1個開關組11包括上橋電晶體Sup和下橋電晶體Sun,第2個開關組11包括上橋電晶體Svp和下橋電晶體Svn,第3個開關組11包括上橋電晶體Swp和下橋電晶體Swn,其中,上橋電晶體Sup、Svp及Swp的第一端彼此電連接,下橋電晶體Sun、Svn及Swn的第二端彼此電連接,上橋電晶體Sup、Svp及Swp的第二端分別電連接於下橋電晶體Sun、Svn及Swn的第一端。Figure 1 is a schematic diagram of the circuit structure of a power conversion circuit according to an embodiment of the present invention. As shown in FIG. 1 , the
直流排電容Cdc用於接收輸入電源Vin,其中直流排電容Cdc的第一端電連接每一上橋電晶體 (Sup、Svp及Swp) 的第一端,且直流排電容Cdc的第二端電連接每一下橋電晶體 (Sun、Svn及Swn) 的第二端。The DC row capacitor Cdc is used to receive the input power Vin, wherein the first end of the DC row capacitor Cdc is electrically connected to the first end of each high-bridge transistor (Sup, Svp, and Swp), and the second end of the DC row capacitor Cdc is electrically connected to the first end of the DC row capacitor Cdc. Connect to the second terminal of each lower bridge transistor (Sun, Svn and Swn).
控制器12比較三相控制命令及控制載波,以取得多個脈寬調變訊號。每一開關組11對應地接收一個脈寬調變訊號,並且在每一開關組11中,依據所對應接收的脈寬調變訊號,上橋電晶體選擇性地導通或截止,下橋電晶體選擇性地截止或導通,從而使得所有開關組11切換輸入電源Vin,產生三相輸出電源驅動馬達2。三相輸出電源包含三個輸出相u、v及w,且三個輸出相u、v及w中的電流分別為Iu、Iv及Iw,另外,三相控制命令包括三個輸出相u、v及w的電壓命令。The
請參閱第1圖及第2圖,其中第2圖為本案一實施例之用於電源轉換電路的控制方法的流程示意圖。本案係利用第1圖之控制器12執行第2圖之控制方法,以實現對電源轉換電路1的控制。如第1圖及第2圖所示,首先,於步驟S1中,比較三相控制命令以及控制載波,取得脈寬調變訊號,並提供脈寬調變訊號驅動電源轉換電路1中的所有開關,讓所有開關切換輸入電源Vin產生三相輸出電源,其中電源轉換電路1中的開關包括所有開關組11中的上橋電晶體 (Sup、Svp及Swp) 及下橋電晶體 (Sun、Svn及Swn)。接著,於步驟S2中,檢測三相輸出電源的電壓及電流之間的相位差是否落入預定相位範圍,其中預定相位範圍以介於-30°至+30°或介於150°至210°為佳。若在步驟S2中檢測到相位差落入預定相位範圍,則執行步驟S3。於步驟S3中,依據三相輸出電源的電壓及電流決定零序電壓為正電壓或負電壓,並對三相控制命令注入零序電壓來取得三相合成命令,並且在一時間週期後檢測三相合成命令中的最大電壓值及最小電壓值。而後,依據零序電壓被決定為正電壓或負電壓,選擇三相合成命令中的最大電壓值或最小電壓值進行邏輯反相運算。具體而言,若在步驟S3中決定零序電壓為正電壓,則執行步驟S4以選擇三相合成命令中的最大電壓值進行邏輯反相運算,反之,若在步驟S3中決定零序電壓為負電壓,則執行步驟S5以選擇三相合成命令中的最小電壓值進行邏輯反相運算。最後,於步驟S6中,在完成邏輯反相運算並停止注入零序電壓後,取得三相輸出期望值,並比較三相輸出期望值以及控制載波,來調節脈寬調變訊號的占空比。Please refer to FIG. 1 and FIG. 2 , wherein FIG. 2 is a schematic flowchart of a control method for a power conversion circuit according to an embodiment of the present case. In this case, the
此外,若在步驟S2中檢測到相位差沒有落入預定相位範圍,則執行步驟S7。於步驟S7中,檢測三相控制命令中的最小控制電壓,並對最小控制電壓進行邏輯反相運算。而後,於步驟S8中,完成對最小控制電壓進行邏輯反相運算後,取得三相輸出命令,並比較三相輸出命令以及控制載波,來調節脈寬調變訊號的占空比。In addition, if it is detected in step S2 that the phase difference does not fall within the predetermined phase range, then step S7 is executed. In step S7, the minimum control voltage in the three-phase control commands is detected, and a logic inversion operation is performed on the minimum control voltage. Then, in step S8, after completing the logic inversion operation on the minimum control voltage, the three-phase output command is obtained, and the three-phase output command and the control carrier are compared to adjust the duty cycle of the PWM signal.
由上述可知,本案之用於驅動馬達2的電源轉換電路1及其控制方法通過翻轉判斷邏輯而非載波來達到向量重新配置。藉此,可有效降低電容漣波,從而降低直流排電容Cdc之溫升以延長直流排電容Cdc的壽命,同時降低馬達2之驅動耗損並提升驅動效率。再者,僅通過既有之控制器12 (例如微處理器) 即可執行本案之控制方法而實現PWM調控,無須外加硬體 (例如FPGA) 進行PWM處理。From the above, it can be seen that the
以下將搭配示例詳述本案中用於電源轉換電路1的控制方法,須注意的是,以下所述控制方法皆由電源轉換電路1的控制器12執行。The control method used in the
以任一輸出相作為示例,第3圖為翻轉控制載波時的波形示意圖,第4圖為翻轉判斷邏輯時的波形示意圖。於第3圖及第4圖中,控制載波為三角波,V*為電壓命令,PWM_H及PWM_L分別為對應之開關組11中之上橋電晶體及下橋電晶體的控制訊號 (被包含於脈寬調變訊號中)。須注意的是,V*可為三相控制命令中任一輸出相u、v或w的電壓命令。於第3圖中,係翻轉控制載波之波形,且在翻轉前後,皆採用判斷邏輯P來根據電壓命令V*與控制載波的比較結果決定脈寬調變訊號是高電壓準位或低電壓準位。於判斷邏輯P中,若電壓命令V*大於控制載波,則切換脈寬調變訊號為高電壓準位,即控制訊號PWM_H為高電壓準位,反之,若電壓命令V*小於控制載波,則切換脈寬調變訊號為低電壓準位,即控制訊號PWM_H為低電壓準位。於第4圖中,係翻轉判斷邏輯及電壓命令V*,在翻轉前後分別採用判斷邏輯P及判斷邏輯N來決定脈寬調變訊號是高電壓準位或低電壓準位,並在翻轉時對電壓命令V*進行邏輯反相運算。翻轉前所採用之判斷邏輯P與前述相同,故不再贅述。翻轉時依據邏輯反相關係式對電壓命令V*進行邏輯反相運算,其中邏輯反相關係式為: (1) 其中, 為完成邏輯反相運算後的電壓命令。在翻轉後所採用的判斷邏輯N中,若電壓命令 大於控制載波,則切換脈寬調變訊號為低電壓準位,即控制訊號PWM_H為低電壓準位,反之,若電壓命令 小於控制載波,則切換脈寬調變訊號為高電壓準位,即控制訊號PWM_H為高電壓準位。須注意的是,若電壓命令經過邏輯反相運算,則其對應之判斷邏輯亦隨之翻轉,反之,若電壓命令未經邏輯反相運算,則其對應之判斷邏輯則維持不變。 Taking any output phase as an example, Figure 3 is a schematic diagram of the waveform when the control carrier is reversed, and Figure 4 is a schematic diagram of the waveform when the judgment logic is reversed. In Figure 3 and Figure 4, the control carrier is a triangle wave, V* is a voltage command, PWM_H and PWM_L are the control signals of the upper bridge transistor and the lower bridge transistor in the corresponding switch group 11 (included in the pulse width modulated signal). It should be noted that V* can be a voltage command of any output phase u, v or w in the three-phase control commands. In Figure 3, the waveform of the control carrier is reversed, and before and after the reversal, the judgment logic P is used to determine whether the PWM signal is a high voltage level or a low voltage level according to the comparison result of the voltage command V* and the control carrier bit. In the judgment logic P, if the voltage command V* is greater than the control carrier, the pulse width modulation signal is switched to a high voltage level, that is, the control signal PWM_H is a high voltage level; otherwise, if the voltage command V* is smaller than the control carrier, then The PWM signal is switched to a low voltage level, that is, the control signal PWM_H is a low voltage level. In Figure 4, it is the inversion judgment logic and the voltage command V*. Before and after the inversion, the judgment logic P and the judgment logic N are respectively used to determine whether the pulse width modulation signal is a high voltage level or a low voltage level, and when the inversion Perform logic inversion operation on the voltage command V*. The judgment logic P used before inversion is the same as the above, so it will not be repeated. When inverting, the voltage command V* is logically inverted according to the logic inversion relational expression, where the logical inversion relational expression is: (1) where, It is the voltage command after the logical inversion operation is completed. In the judgment logic N adopted after inversion, if the voltage command If it is greater than the control carrier, switch the PWM signal to a low voltage level, that is, the control signal PWM_H is a low voltage level. On the contrary, if the voltage command If it is less than the control carrier, the PWM signal is switched to a high voltage level, that is, the control signal PWM_H is a high voltage level. It should be noted that if the voltage command undergoes a logic inversion operation, the corresponding judgment logic will also be reversed. On the contrary, if the voltage command has not been logic inversion operation, the corresponding judgment logic will remain unchanged.
如第3圖及第4圖所示,無論是翻轉控制載波或翻轉判斷邏輯,脈衝寬度調變訊號皆相同。須注意的是,下橋電晶體的控制訊號PWM_L與上橋電晶體的控制訊號PWM_H近似互補,其中在翻轉前或翻轉後的時間段中,上橋電晶體及下橋電晶體的切換時刻之間具有死區時間,而在翻轉時,上橋電晶體及下橋電晶體同步進行切換而不存在死區時間。As shown in Fig. 3 and Fig. 4, the PWM signal is the same regardless of whether the control carrier is inverted or the judgment logic is inverted. It should be noted that the control signal PWM_L of the low-bridge transistor is approximately complementary to the control signal PWM_H of the high-bridge transistor. There is a dead time between them, and when flipping, the upper bridge transistor and the lower bridge transistor are switched synchronously without dead time.
在三相輸出電源的電壓及電流之間的相位差沒有落入預定相位範圍的情況下,則檢測三相控制命令中的最小控制電壓 (即三個輸出相u、v及w的電壓命令中的最小值)。並依據等式 (1) 所示之邏輯反相關係式對最小控制電壓進行邏輯反相運算,其餘兩個輸出相中的電壓命令則維持不變,以藉此取得三相輸出命令。詳細而言,三相輸出命令包含經過邏輯反相運算後的最小控制電壓,且三相輸出命令還包含其餘兩個輸出相中的電壓命令。而後,通過比較三相輸出命令及控制載波,來調節脈寬調變訊號的占空比,其中,係基於判斷邏輯N來比較經過邏輯反相運算後的最小控制電壓與控制載波,並基於判斷邏輯P來比較其餘兩個輸出相的電壓命令與控制載波。When the phase difference between the voltage and current of the three-phase output power supply does not fall into the predetermined phase range, then detect the minimum control voltage in the three-phase control command (that is, the voltage command of the three output phases u, v and w minimum value). According to the logical inversion relation shown in equation (1), the minimum control voltage is logically inverted, and the voltage commands in the other two output phases remain unchanged, so as to obtain the three-phase output command. Specifically, the three-phase output command includes the minimum control voltage after logic inversion operation, and the three-phase output command also includes voltage commands in the other two output phases. Then, by comparing the three-phase output command and the control carrier, the duty ratio of the PWM signal is adjusted, wherein the minimum control voltage and the control carrier after the logic inversion operation are compared based on the judgment logic N, and based on the judgment Logic P to compare the voltage command and control carrier of the remaining two output phases.
另外,在三相輸出電源的電壓及電流之間的相位差落入預定相位範圍的情況下,本案於三相控制命令中注入零序電壓,以避免在翻轉時因不存在死區時間而影響電路可靠性。第5圖為例示於三相控制命令中注入零序電壓時的波形示意圖,且於第5圖之示例中,零序電壓為正電壓,並示出三相控制命令中最大之電壓命令作為示例。如第5圖所示,於時刻t1,於電壓命令V* 中注入零序電壓。在零序電壓為正電壓時,零序電壓的大小等於最大之電壓命令V* 與控制載波之波峰值間的差值。反之,在零序電壓為負電壓時,零序電壓的大小等於最小之電壓命令與控制載波之波谷值間的差值。而後,於時刻t2,將判斷邏輯P翻轉為判斷邏輯N,並依據等式 (1) 所示之邏輯反相關係式對電壓命令V* 進行邏輯反相運算而獲得電壓命令
。最後,於時刻t3停止注入零序電壓,且在時刻t3至t4期間,基於判斷邏輯N,比較未被注入零序電壓的電壓命令
及控制載波,來調節對應開關組11中之脈寬調變訊號的占空比。需注意的是,於第5圖之示例中,時刻t1至t2期間以及時刻t2至t3期間分別具有一個週期的控制載波,然實際上並不以此為限,時刻t1至t2期間以及時刻t2至t3期間可分別具有多個週期的控制載波。
In addition, when the phase difference between the voltage and current of the three-phase output power supply falls within the predetermined phase range, this case injects zero-sequence voltage into the three-phase control command to avoid the influence caused by the absence of dead time during inversion. circuit reliability. Figure 5 is a schematic diagram of the waveform when zero-sequence voltage is injected into the three-phase control command, and in the example in Figure 5, the zero-sequence voltage is a positive voltage, and shows the largest voltage command among the three-phase control commands as an example . As shown in FIG. 5, at time t1, a zero-sequence voltage is injected into the voltage command V*. When the zero-sequence voltage is a positive voltage, the magnitude of the zero-sequence voltage is equal to the difference between the maximum voltage command V* and the peak value of the control carrier wave. Conversely, when the zero-sequence voltage is a negative voltage, the magnitude of the zero-sequence voltage is equal to the difference between the minimum voltage command and the valley value of the control carrier. Then, at time t2, the judgment logic P is reversed to judgment logic N, and the voltage command V* is logically inverted according to the logic inversion relation shown in equation (1) to obtain the voltage command . Finally, stop injecting the zero-sequence voltage at time t3, and during the period from time t3 to t4, based on the judgment logic N, compare the voltage command that has not been injected with zero-sequence voltage And control the carrier to adjust the duty ratio of the pulse width modulation signal in the
由第5圖可看出,在時刻t1至t2期間,被注入零序電壓之電壓命令V* 維持等於控制載波的波峰值,故基於判斷邏輯P,上橋電晶體的控制訊號PWM_H持續處於高電壓準位,下橋電晶體的控制訊號PWM_L持續處於低電壓準位。而在時刻t2至t3期間,被注入零序電壓之電壓命令 維持等於控制載波的波谷值,故基於判斷邏輯N,上橋電晶體的控制訊號PWM_H持續處於高電壓準位,下橋電晶體的控制訊號PWM_L持續處於低電壓準位。因此,於時刻t2,即在翻轉邏輯和進行邏輯反相運算時,上橋電晶體及下橋電晶體均不會進行切換。藉此,可避免在翻轉邏輯時因上橋電晶體及下橋電晶體同步切換 (即不存在死區時間) 而影響電路可靠性。於一些實施例中,在對三相控制命令注入零序電壓前,調整脈寬調變訊號的占空比為100%或0%。 It can be seen from Figure 5 that during the period from time t1 to t2, the voltage command V* injected into the zero-sequence voltage remains equal to the peak value of the control carrier, so based on the judgment logic P, the control signal PWM_H of the high-bridge transistor is continuously at high Voltage level, the control signal PWM_L of the lower bridge transistor is continuously at the low voltage level. During the period from time t2 to t3, the voltage command injected into the zero-sequence voltage Keep equal to the valley value of the control carrier, so based on the judgment logic N, the control signal PWM_H of the high-bridge transistor is continuously at the high voltage level, and the control signal PWM_L of the low-bridge transistor is continuously at the low voltage level. Therefore, at time t2, that is, when inverting logic and performing logic inversion operations, neither the high-bridge transistor nor the low-bridge transistor will switch. In this way, it is possible to avoid affecting the reliability of the circuit due to synchronous switching of the high-bridge transistor and the low-bridge transistor (that is, there is no dead time) when the logic is flipped. In some embodiments, before injecting the zero-sequence voltage into the three-phase control command, the duty cycle of the PWM signal is adjusted to 100% or 0%.
以下以第6圖例示說明如何依據三相輸出電源的電壓及電流決定零序電壓為正電壓或負電壓。The following figure 6 illustrates how to determine whether the zero-sequence voltage is positive or negative according to the voltage and current of the three-phase output power supply.
第6圖為三相輸出電源的電壓及電流波形示意圖。於第6圖中,電壓及電流之間的相位差落入預定相位範圍,Vu、Vv及Vw分別為三相輸出電源中三個輸出相u、v及w的電壓,且分別以實線、虛線及點鏈線標示電壓Vu、Vv及Vw的波形。Iu、Iv及Iw分別為三相輸出電源中三個輸出相u、v及w的電流,且分別以實線、虛線及點鏈線標示電流Iu、Iv及Iw的波形。波形旁標註之 “+” 或 “-” 分別代表採用判斷邏輯P或判斷邏輯N。在各個電壓區段I、II、III、IV、V及VI中,電壓相角的範圍不同,如表1所示。在各個電流區段A、B、C、D、E及F中,電流Iu、Iv及Iw的正負關係不同,如表2所示。Fig. 6 is a schematic diagram of the voltage and current waveforms of the three-phase output power supply. In Fig. 6, the phase difference between voltage and current falls within a predetermined phase range, and Vu, Vv, and Vw are voltages of three output phases u, v, and w in a three-phase output power supply, respectively, and are represented by solid lines, Dashed lines and dotted lines indicate the waveforms of the voltages Vu, Vv and Vw. Iu, Iv, and Iw are the currents of the three output phases u, v, and w in the three-phase output power supply, respectively, and the waveforms of the currents Iu, Iv, and Iw are marked by solid lines, dashed lines, and dotted lines, respectively. The "+" or "-" marked next to the waveform represents the use of judgment logic P or judgment logic N respectively. In each voltage section I, II, III, IV, V and VI, the range of the voltage phase angle is different, as shown in Table 1. In each current section A, B, C, D, E, and F, the positive and negative relationships of the currents Iu, Iv, and Iw are different, as shown in Table 2.
表1:
表2:
通過表1及表2得知當前三相輸出電源的電壓及電流所在區段後,即可依據表3決定零序電壓為正電壓或負電壓。於表3中,Vz+ 代表零序電壓為正電壓,Vz- 代表零序電壓為負電壓,Vz0代表可任意選擇零序電壓為正電壓或負電壓。After knowing the voltage and current section of the current three-phase output power supply through Table 1 and Table 2, you can determine whether the zero-sequence voltage is a positive voltage or a negative voltage according to Table 3. In Table 3, Vz+ means that the zero-sequence voltage is a positive voltage, Vz- means that the zero-sequence voltage is a negative voltage, and Vz0 means that the zero-sequence voltage can be arbitrarily selected as a positive voltage or a negative voltage.
表3:
理想上,電壓Vu、Vv及Vw和電流Iu、Iv及Iw與三相控制命令中各相的電壓命令及電流命令一致,故於一些實施例中,亦可通過電壓及電流命令決定零序電壓為正電壓或負電壓。Ideally, the voltages Vu, Vv, and Vw and the currents Iu, Iv, and Iw are consistent with the voltage commands and current commands of each phase in the three-phase control commands, so in some embodiments, the zero-sequence voltage can also be determined by the voltage and current commands be positive or negative voltage.
第7圖例示出對三相控制命令注入零序電壓的波形變化。於第7圖中,三相控制命令包含三個輸出相u、v及w的電壓命令Vu*、Vv*及Vw*,且三相控制命令中的最大值、中間值及最小值依序為電壓命令Vu*、Vv*及Vw*。再者,於第7圖中,分別以實線及虛線例示出控制載波的波峰及波谷。於一些實施例中,在決定零序電壓為正電壓之後,檢測三相控制命令中的最大值 (即電壓命令Vu*),並檢測控制載波在切換週期中的波峰值。接著,計算波峰值及三相控制命令的最大值之間的第一電壓差,並且第一電壓差為該正電壓之電壓值 (即零序電壓之電壓值)。最後,將三相控制命令與正電壓的電壓值進行疊加,以形成三相合成命令。於另一實施例中,在決定零序電壓為負電壓之後,檢測三相控制命令中的最小值 (即電壓命令Vw*),並檢測控制載波在切換週期中的波谷值。接著,計算波谷值及三相控制命令的最小值之間的第二電壓差,並且第二電壓差為該負電壓之電壓值 (即零序電壓之電壓值)。最後,將三相控制命令與負電壓的電壓值進行疊加,以形成三相合成命令。Figure 7 illustrates the waveform change of the zero-sequence voltage injected into the three-phase control command. In Fig. 7, the three-phase control command includes the voltage commands Vu*, Vv* and Vw* of the three output phases u, v and w, and the maximum value, intermediate value and minimum value in the three-phase control command are sequentially Voltage commands Vu*, Vv* and Vw*. Furthermore, in Fig. 7, the peaks and troughs of the control carrier are illustrated by solid lines and broken lines, respectively. In some embodiments, after the zero-sequence voltage is determined to be a positive voltage, the maximum value of the three-phase control commands (ie, the voltage command Vu*) is detected, and the peak value of the control carrier in the switching period is detected. Next, calculate the first voltage difference between the peak value of the wave and the maximum value of the three-phase control command, and the first voltage difference is the voltage value of the positive voltage (ie, the voltage value of the zero-sequence voltage). Finally, the three-phase control command and the voltage value of the positive voltage are superimposed to form a three-phase composite command. In another embodiment, after the zero-sequence voltage is determined to be a negative voltage, the minimum value of the three-phase control commands (ie, the voltage command Vw*) is detected, and the valley value of the control carrier in the switching cycle is detected. Then, calculate the second voltage difference between the valley value and the minimum value of the three-phase control command, and the second voltage difference is the voltage value of the negative voltage (ie, the voltage value of the zero-sequence voltage). Finally, the three-phase control command and the voltage value of the negative voltage are superimposed to form a three-phase synthesis command.
第8圖例示出於三相控制命令中注入零序電壓時各輸出相的脈寬調變訊號的波形。於第8圖所示實施例中,其中
為對電壓命令Vu*進行邏輯反相運算後所獲得的電壓命令,PWM_u、PWM_v及PWM_w分別為輸出相u、v及w所對應之開關組11的上橋電晶體Sup、Svp及Swp的控制訊號。於第8圖中,以實線標示電壓命令Vu*及
的波形,以虛線標示電壓命令Vv*的波形,以點鏈線標示電壓命令Vw*的波形。如第8圖所示,在三相輸出電源的電壓及電流之間的相位差落入預定相位範圍的情況下,於時刻t1,對三相控制命令 (包含電壓命令Vu*、Vv*及Vw*) 注入零序電壓,於此實施例中,零序電壓為正電壓。被注入零序電壓後的電壓命令Vu*、Vv*及Vw*形成三相合成命令。經過一時間週期後 (即時刻t1至t2之時間段),檢測三相合成命令中的最大電壓值及最小電壓值,於此實施例中,三相合成命令中的最大電壓值及最小電壓值分別為被注入零序電壓的電壓命令Vu*及Vw*。因零序電壓為正電壓,故於時刻t2選擇三相合成命令中的最大電壓值 (即電壓命令Vu*),並依據等式 (1) 所示之邏輯反相關係式對最大電壓值進行邏輯反相運算而獲得電壓命令
。於時刻t3,停止注入零序電壓,此時電壓命令
等同於對未被注入零序電壓之電壓命令Vu*進行邏輯反相運算所得之電壓命令。再者,於停止注入零序電壓後,電壓命令
、Vv*及Vw*形成三相輸出期望值。最後,通過比較三相輸出期望值及控制載波,來調節脈寬調變訊號 (即控制訊號PWM_u、PWM_v及PWM_w) 的占空比。
Figure 8 illustrates the waveforms of the PWM signals of each output phase when zero-sequence voltage is injected into the three-phase control command. In the embodiment shown in Figure 8, where It is the voltage command obtained after performing logic inversion operation on the voltage command Vu*, PWM_u, PWM_v and PWM_w are respectively the control of the upper bridge transistor Sup, Svp and Swp of the
須注意的是,於任一時間點,係依據當下之判斷邏輯將當下之電壓命令與控制載波進行比較,以根據比較結果決定脈寬調變訊號為高電壓準位或低電壓準位。於第8圖所示實施例中,因於時刻t2對輸出相u對應之電壓命令Vu*進行邏輯反相運算,輸出相u對應之判斷邏輯一併由判斷邏輯P翻轉為判斷邏輯N,故於時刻t0至t2期間,係基於判斷邏輯P比較電壓命令Vu*及控制載波來決定控制訊號PWM_u之波形,而在時刻t2至t4期間,則基於判斷邏輯N比較電壓命令 及控制載波來決定控制訊號PWM_u之波形。另外,若電壓命令未經邏輯反相運算,則其對應之判斷邏輯則維持不變。因此,對於輸出相v及w而言,由於其電壓命令Vv*及Vw*均未經邏輯反相運算,故於時刻t0至t4,始終基於判斷邏輯P比較電壓命令Vv*及Vw*與控制載波來決定控制訊號PWM_v及PWM_w之波形。 It should be noted that at any point in time, the current voltage command is compared with the control carrier according to the current judgment logic, so as to determine whether the PWM signal is a high voltage level or a low voltage level according to the comparison result. In the embodiment shown in FIG. 8, since the logic inversion operation is performed on the voltage command Vu* corresponding to the output phase u at time t2, the judgment logic one corresponding to the output phase u is reversed from the judgment logic P to the judgment logic N, so During the period from time t0 to t2, the waveform of the control signal PWM_u is determined based on the judgment logic P comparing the voltage command Vu* and the control carrier, and during the period from time t2 to t4, based on the judgment logic N comparing the voltage command And control the carrier to determine the waveform of the control signal PWM_u. In addition, if the voltage command has not been logically inverted, its corresponding judgment logic remains unchanged. Therefore, for the output phases v and w, since the voltage commands Vv* and Vw* have not been logically inverted, from time t0 to t4, the voltage commands Vv* and Vw* are always compared with the control based on the judgment logic P The carrier wave determines the waveforms of the control signals PWM_v and PWM_w.
具體而言,在時刻t0至t1期間,基於判斷邏輯P對三相控制命令與控制載波進行比較,如果三相控制命令大於控制載波時,則切換脈寬調變訊號為高電壓準位,如果三相控制命令小於控制載波時,則切換脈寬調變訊號為低電壓準位。以輸出相u為例,若三相控制命令中之電壓命令Vu*大於控制載波時,則切換脈寬調變訊號中之控制訊號PWM_u為高電壓準位,如果三相控制命令中之電壓命令Vu*小於控制載波時,則切換脈寬調變訊號中之控制訊號PWM_u為低電壓準位。時刻t1至t2期間決定脈寬調變訊號之波形的方式與時刻t0至t1期間相似,故於此不再贅述。Specifically, during the period from time t0 to t1, the three-phase control command is compared with the control carrier based on the judgment logic P. If the three-phase control command is greater than the control carrier, the PWM signal is switched to a high voltage level. If When the three-phase control command is smaller than the control carrier, the PWM signal is switched to a low voltage level. Take the output phase u as an example, if the voltage command Vu* in the three-phase control command is greater than the control carrier, then switch the control signal PWM_u in the pulse width modulation signal to a high voltage level, if the voltage command in the three-phase control command When Vu* is smaller than the control carrier, the control signal PWM_u in the pulse width modulation signal is switched to a low voltage level. The method of determining the waveform of the PWM signal during the period from time t1 to t2 is similar to that during the period from time t0 to t1 , so it will not be repeated here.
在時刻t3至t4期間,三相輸出期望值包含經由邏輯反相運算取得之電壓命令 以及未經由邏輯反相運算取得之電壓命令Vv*及Vw*。因此,基於判斷邏輯N對電壓命令 與控制載波進行比較,如果電壓命令 大於控制載波時,則切換脈寬調變訊號中之控制訊號PWM_u為低電壓準位,如果電壓命令 小於控制載波時,則切換脈寬調變訊號中之控制訊號PWM_u為高電壓準位。此外,基於判斷邏輯P對電壓命令Vv與控制載波進行比較,如果電壓命令Vv*大於控制載波時,則切換脈寬調變訊號中之控制訊號PWM_v為高電壓準位,如果電壓命令Vv*小於控制載波時,則切換脈寬調變訊號中之控制訊號PWM_v為低電壓準位。再者,基於判斷邏輯P對電壓命令Vw*與控制載波進行比較,如果電壓命令Vw*大於控制載波時,則切換脈寬調變訊號中之控制訊號PWM_w為高電壓準位,如果電壓命令Vw*小於控制載波時,則切換脈寬調變訊號中之控制訊號PWM_w為低電壓準位。時刻t2至t3期間決定脈寬調變訊號之波形的方式與時刻t3至t4期間相似,故於此不再贅述。 During the period from time t3 to t4, the expected value of three-phase output includes the voltage command obtained through logic inversion operation And voltage commands Vv* and Vw* obtained without logic inversion operation. Therefore, based on the judgment logic N for the voltage command compared with the control carrier, if the voltage command When it is greater than the control carrier, switch the control signal PWM_u in the pulse width modulation signal to a low voltage level. If the voltage command When it is less than the control carrier, the control signal PWM_u in the pulse width modulation signal is switched to a high voltage level. In addition, based on the judgment logic P, the voltage command Vv is compared with the control carrier. If the voltage command Vv* is greater than the control carrier, the control signal PWM_v in the pulse width modulation signal is switched to a high voltage level. If the voltage command Vv* is less than When controlling the carrier, switch the control signal PWM_v in the pulse width modulation signal to a low voltage level. Furthermore, based on the judgment logic P, the voltage command Vw* is compared with the control carrier. If the voltage command Vw* is greater than the control carrier, the control signal PWM_w in the pulse width modulation signal is switched to a high voltage level. If the voltage command Vw *When it is less than the control carrier, switch the control signal PWM_w in the pulse width modulation signal to a low voltage level. The manner of determining the waveform of the PWM signal during the period from time t2 to t3 is similar to that during the period from time t3 to t4 , so it will not be repeated here.
綜上所述,本案提供一種用於驅動馬達的電源轉換電路及其控制方法,其通過翻轉判斷邏輯而非載波來達到向量重新配置。藉此,可有效降低電容漣波,從而降低電容溫升以延長電容壽命,同時降低馬達之驅動耗損並提升驅動效率。再者,僅通過既有之控制器 (例如微處理器) 即可執行本案之控制方法而實現PWM調控,無須外加硬體 (例如FPGA) 進行PWM處理。To sum up, this case provides a power conversion circuit for driving a motor and its control method, which achieves vector reconfiguration by inverting judgment logic instead of carrier. In this way, the capacitor ripple can be effectively reduced, thereby reducing the temperature rise of the capacitor to prolong the life of the capacitor, while reducing the driving loss of the motor and improving the driving efficiency. Furthermore, the control method of this application can be implemented to realize PWM regulation only through an existing controller (such as a microprocessor), and no external hardware (such as FPGA) is required for PWM processing.
須注意,上述僅是為說明本案而提出之較佳實施例,本案不限於所述之實施例,本案之範圍由如附專利申請範圍決定。且本案得由熟習此技術之人士任施匠思而為諸般修飾,然皆不脫如附專利申請範圍所欲保護者。It should be noted that the above is only a preferred embodiment proposed to illustrate this case, and this case is not limited to the described embodiment, and the scope of this case is determined by the scope of the attached patent application. Moreover, this case can be modified in various ways by the people who are familiar with this technology with Shi Jiang's thinking, but all of them will not break away from the desired protection of the scope of the attached patent application.
1:電源轉換電路 2:馬達 11:開關組 Cdc:直流排電容 12:控制器 Sup、Svp、Swp:上橋電晶體 Sun、Svn、Swn:下橋電晶體 Vin:輸入電源 Iu、Iv、Iw:電流 V*:電壓命令 PWM_H、PWM_L:控制訊號 :邏輯反相運算後的電壓命令 t0、t1、t2、t3、t4:時刻 Vu、Vv、Vw:電壓 I、II、III、IV、V、VI:電壓區段 A、B、C、D、E、F:電流區段 Vu*、Vv*、Vw*:電壓命令 :邏輯反相運算後的電壓命令 PWM_u、PWM_v、PWM_w:控制訊號 S1、S2、S3、S4、S5、S6、S7、S8:步驟1: Power conversion circuit 2: Motor 11: Switch group Cdc: DC row capacitor 12: Controller Sup, Svp, Swp: Upper bridge transistors Sun, Svn, Swn: Lower bridge transistors Vin: Input power supply Iu, Iv, Iw : current V*: voltage command PWM_H, PWM_L: control signal : Voltage command after logic inversion operation t0, t1, t2, t3, t4: Time Vu, Vv, Vw: Voltage I, II, III, IV, V, VI: Voltage section A, B, C, D, E, F: current section Vu*, Vv*, Vw*: voltage command : Voltage commands PWM_u, PWM_v, PWM_w after logic inversion operation: Control signals S1, S2, S3, S4, S5, S6, S7, S8: Steps
第1圖為本案一實施例之電源轉換電路的電路結構示意圖。Figure 1 is a schematic diagram of the circuit structure of a power conversion circuit according to an embodiment of the present invention.
第2圖為本案一實施例之用於電源轉換電路的控制方法的流程示意圖。FIG. 2 is a schematic flowchart of a control method for a power conversion circuit according to an embodiment of the present invention.
第3圖為翻轉控制載波時的波形示意圖。Figure 3 is a schematic diagram of the waveform when inverting the control carrier.
第4圖為翻轉判斷邏輯時的波形示意圖。Figure 4 is a schematic diagram of the waveform when the judgment logic is reversed.
第5圖為例示於三相控制命令中注入零序電壓時的波形示意圖。FIG. 5 is an example of a waveform diagram when zero-sequence voltage is injected into a three-phase control command.
第6圖為三相輸出電源的電壓及電流波形示意圖。Fig. 6 is a schematic diagram of the voltage and current waveforms of the three-phase output power supply.
第7圖例示出對三相控制命令注入零序電壓時的波形變化。Figure 7 illustrates the waveform changes when zero-sequence voltage is injected into the three-phase control command.
第8圖例示出於三相控制命令中注入零序電壓時各輸出相的脈寬調變訊號的波形。Figure 8 illustrates the waveforms of the PWM signals of each output phase when zero-sequence voltage is injected into the three-phase control command.
S1、S2、S3、S4、S5、S6、S7、S8:步驟 S1, S2, S3, S4, S5, S6, S7, S8: steps
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TW392998U (en) * | 1998-06-16 | 2000-06-01 | Iindustrial Technology Res Ins | Control circuit for 3-phase DC/AC power converter |
TW201731206A (en) * | 2016-02-17 | 2017-09-01 | 丁景信 | Method for driving an AC motor by two-phase electric power and power generation method |
TW201947865A (en) * | 2018-05-14 | 2019-12-16 | 茂達電子股份有限公司 | Motor driving circuit and method thereof |
US10601343B1 (en) * | 2019-01-16 | 2020-03-24 | Rockwell Automation Technologies, Inc. | Power conversion system with PWM carrier transition smoothing and autotuning |
US11165359B2 (en) * | 2017-04-24 | 2021-11-02 | Panasonic Intellectual Property Management Co., Ltd. | Power conversion system configured to perform power conversion between direct current and three-phase alternating current |
TW202220366A (en) * | 2020-09-30 | 2022-05-16 | 日商日本電產股份有限公司 | Motor drive circuit and motor module |
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TW392998U (en) * | 1998-06-16 | 2000-06-01 | Iindustrial Technology Res Ins | Control circuit for 3-phase DC/AC power converter |
TW201731206A (en) * | 2016-02-17 | 2017-09-01 | 丁景信 | Method for driving an AC motor by two-phase electric power and power generation method |
US11165359B2 (en) * | 2017-04-24 | 2021-11-02 | Panasonic Intellectual Property Management Co., Ltd. | Power conversion system configured to perform power conversion between direct current and three-phase alternating current |
TW201947865A (en) * | 2018-05-14 | 2019-12-16 | 茂達電子股份有限公司 | Motor driving circuit and method thereof |
US10601343B1 (en) * | 2019-01-16 | 2020-03-24 | Rockwell Automation Technologies, Inc. | Power conversion system with PWM carrier transition smoothing and autotuning |
TW202220366A (en) * | 2020-09-30 | 2022-05-16 | 日商日本電產股份有限公司 | Motor drive circuit and motor module |
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