JP2012039716A - Motor controller and motor control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor controller correcting phase delay of a current of each phase of a polyphase motor.SOLUTION: The motor controller includes a power conversion means which is connected to a polyphase motor to convert DC power to AC power, a plurality of current detection means which detect phase currents of at least two phases of the polyphase motor respectively, a phase delay amount setting means which sets a phase delay amount of the phase current of each phase of the polyphase motor, a coordinates conversion means which converts phase current of a fixed coordinate system of each phase, including the phase current of two phases detected by the plurality of current detection means, to a current of a rotating coordinate system, and a control means which controls the power conversion means based on the current of the rotating coordinate system converted by the coordinates conversion means and an output target value of the polyphase motor which is inputted from outside. The coordinates conversion means sets a plurality of correction values corresponding to each phase based on the phase delay amount of each phase that is set by the phase delay amount setting means, and uses the plurality of correction values to convert the phase current of the fixed coordinate system to the current of the rotating coordinate system.

Description

  The present invention relates to a motor control device and a motor control method.

  A current detector for the output current of a power converter that supplies alternating current of variable voltage and variable frequency to the AC motor, a current detection circuit that functions as a filter for removing noise components, and an output signal of the detection circuit at each frequency of the AC motor In a power converter having a coordinate converter that converts two current components of a rotating rotating magnetic field coordinate system, the product of the output of the coordinate converter and each frequency of the AC motor is used as the current component of the output of the coordinate converter. There is known an AC motor detection delay compensation device that compensates for a phase delay of a fundamental wave component of a current detection value by providing an adder for mutual addition.

Japanese Patent Publication No.7-118953

  However, in the above detection delay compensation device, the high frequency noise component is removed using the same filter for the three-phase detection current, and the phase delay of the fundamental wave component of the detection signal accompanying the same filter is compensated. When the phase lags of the three-phase detection currents are different from each other, there is a problem that the phase lag cannot be compensated accurately.

  The problem to be solved by the present invention is to provide a motor control device that corrects the phase delay of the current of each phase of a multiphase motor.

  The present invention sets the phase lag amount of the phase current of each phase of the multiphase motor, and uses a plurality of correction values set based on the respective phase lag amounts, and the phase current of the fixed coordinate system of each phase The above-mentioned problem is solved by converting into a detected current of the rotating coordinate system.

  According to the present invention, the correction value corresponding to each phase delay amount of the phase current of each phase motor is used to correct the phase current corresponding to each phase, and to convert from the fixed coordinate system to the rotating coordinate system. Even if the phase lags of the phases are different, there is an effect that each phase lag can be corrected.

1 is a block diagram of a motor control device according to an embodiment of the present invention. It is a figure which shows the table stored in the coordinate converter of FIG. It is a graph which shows the time characteristic of the phase current of each phase in the motor control apparatus of FIG. 2 is a graph showing time characteristics of dq-axis current in the motor control device of FIG. 1. It is a block diagram of a motor control device concerning other embodiments of the present invention. It is a graph which shows the time characteristic of the phase current of each phase in the motor control apparatus of FIG. 5 is a graph showing time characteristics of dq-axis current in the motor control device of FIG. 4.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<< First Embodiment >>
FIG. 1 is a block diagram of a motor control device according to an embodiment of the invention. Although not shown in detail, when the motor control device of this example is provided in an electric vehicle, the three-phase AC power permanent magnet motor 8 is driven as a travel drive source and is coupled to the axle of the electric vehicle. In addition, the motor control apparatus of this example is applicable also to vehicles other than electric vehicles, such as a hybrid vehicle (HEV), for example.

  The motor control device of this example includes a current-voltage map 1, a current controller 2, a coordinate converter 3, a PWM (Pulse Width Modulation) converter 4, a battery 5, an inverter 6, a current sensor 7, A motor 8, a magnetic pole position detector 9, a coordinate converter 10, a rotation speed calculator 11, an LPF (Low Pass Filter) 12, and a gain correction unit 13 are provided.

The current voltage map 1 includes a torque command value (T ^* ) input from the outside as an output target value of the motor 8, an angular frequency (ω) of the motor 8 which is an output of the rotation speed calculator 11, and a battery. 5, a voltage (V _dc ) input to the inverter 5 is input. In the current voltage map 1, the torque command value (T ^* ), the angular frequency (ω), and the voltage (V _dc ) are used as indexes, and the dq axis current command value (i ^* _d , i ^* _q ) and the dq axis non-interference voltage. A map for outputting the command values (V ^* _{d_dcpl} , V ^* _{q_dcpl} ) is stored, and the current-voltage map 1 refers to the map so that the input torque command value (T ^* ), angular frequency Dq-axis current command values (i ^* _d , i ^* _q ) and dq-axis non-interference voltage command values (V ^* _{d_dcpl} , V ^* _{q_dcpl} ) corresponding to (ω) and voltage (V _dc ) are calculated and output. . Here, the dq axis represents a component of the rotating coordinate system. dq-axis non-interacting voltage command value _{^{(V * d_dcpl, V * q_dcpl}} ) for, when a current flows through the d-axis and q-axis interference voltage .omega.L _q i _q is the .omega.L _d i _d q-axis in the d-axis occurs _Therefore , the dq-axis non-interference voltage command values (V ^* _{d_dcpl} , V ^* _{q_dcpl} ) are voltages for canceling the interference voltage. L _d represents the d-axis reactance, and L _q represents the q-axis reactance.

The LPF 12 receives the dq axis non-interference voltage command values (V ^* _{d_dcpl} , V ^* _{q_dcpl} ), cuts the high frequency band, and outputs the voltage command values (V ^* _{d_dcpl_flt} , V ^* _{q_dcpl_flt} ).

Current controller 2 is input with the dq-axis current command value ^{_{(i * d, i * q}} ), voltage command value ^{_{(V * d_dcpl_flt, V * q_dcpl_flt}} ) and dq-axis current _(i d, i _q), the control operation To output dq axis voltage command values (V ^* _d , V ^* _q ).

The coordinate converter 3 receives the dq-axis voltage command value (V ^* _d , V ^* _q ) and the detected value θ of the magnetic pole position detector 9 as input, and uses the following equation (1) to calculate the dq of the rotating coordinate system. The shaft voltage command values (V ^* _d , V ^* _q ) are converted into voltage command values (V ^* _u , V ^* _v , V ^* _w ) for the u, v, and w axes in the fixed coordinate system.

ＰＷＭ変換器４は、入力される電圧指令値（Ｖ^＊ _ｕ、Ｖ^＊ _ｖ、Ｖ^＊ _ｗ）に基づき、インバータ６のスイッチング素子の駆動信号（Ｄ^＊ _ｕｕ、Ｄ^＊ _ｕｌ、Ｄ^＊ _ｖｕ、Ｄ^＊ _ｖｌ、Ｄ^＊ _ｗｕ、Ｄ^＊ _ｗｌ）を生成し、インバータ６に出力する。

Based on the input voltage command values (V ^* _u , V ^* _v , V ^* _w ), the PWM converter 4 drives drive signals (D ^* _uu , D ^* _ul , D ^* _vu , D) of the inverter 6. ^* _Vl , D ^* _wu , D ^* _wl ) are generated and output to the inverter 6.

The battery 5 is a DC power source including a secondary battery, and serves as a power source for the vehicle in this example. The inverter 6 is configured by a three-phase inverter circuit in which a plurality of circuits in which switching elements (not shown) such as MOSFETs and IGBTs are connected in pairs are connected. Output signals (D ^* _uu , D ^* _ul , D ^* _vu , D ^* _vl , D ^* _wu , D ^* _wl ) of the PWM converter are input to each switching element. Then, the DC voltage of the DC power supply is converted into AC voltage (V _u , V _v , V _w ) by the switching operation of the switching element, and is input to the motor 8. When the motor 8 operates as a generator, the inverter 6 converts the AC voltage output from the motor 8 into a DC voltage and outputs it to the battery 5. Thereby, the battery 5 is charged.

The current sensor 7 is connected between the inverter 6 and the motor 8 and detects three-phase AC phase currents (i _u , i _v , i _w ). The current sensor 7 includes a plurality of sensors, and the plurality of sensors are connected to each phase.

  The motor 8 is a multiphase motor and is connected to the inverter 6. The motor 8 also operates as a generator. The magnetic pole position detector 9 is a detector that is provided in the motor 8 and detects the position of the magnetic pole of the motor 8, and outputs the detected value (θ) to the rotational speed calculator 11. The rotation speed calculator 11 calculates the angular frequency (ω) of the motor 8 from the detection value (θ) of the magnetic pole position detector 9.

The gain correction unit 13 performs gain correction on the phase currents (i _u , i _v , i _w ) of each phase, and outputs the phase currents (i _{u_gain} , _{iv_gain} , i _{w_gain} ) after gain correction to the coordinate converter 10. To do. Since the current sensor 7 is a plurality of sensors, production-fixed variations occur in each phase. Therefore, in this example, a gain correction unit 13 is provided between the current sensor 7 and the coordinate converter 10 to correct the phase current of each phase.

The corrected phase currents (i _{u — gain} , i _{v — gain} , i _{w — gain} ) are expressed by equation (2).

ただし、ｋ_ｕ、ｋ_ｖ、ｋ_ｗは、ｕ、ｖ、ｗ相のそれぞれのゲイン係数を表しており、各相に接続される電流センサ７に応じて予め設定される係数である。

However, k _u , k _v , and k _w represent gain coefficients of the u, v, and w phases, and are coefficients that are set in advance according to the current sensor 7 connected to each phase.

The coordinate converter 10 includes a phase delay amount setting unit 100 and is a control unit that performs three-phase to two-phase conversion. The phase delay amount setting unit 100 sets the phase delay amount of each phase, which will be described later, based on the angular frequency (ω) of the rotation speed calculator 11. The coordinate converter 10 calculates the correction values (a, b, c, d, e, f) of the three phases based on the phase delay amount, and calculates the correction values (a, b, c, d, e, f) using the corrected phase currents (i _{u — gain} , i _{v — gain} , i _{w — gain} ) and the detected value θ of the magnetic pole position detector 9 as inputs, the phase current of the fixed coordinate system ( _{i u_gain,} i v_gain, converts the _{i w_gain)} phase current of the rotating coordinate system _(i d, the _{i w).}

ここで、座標変換器１０により設定される、補正値（ａ、ｂ、ｃ、ｄ、ｅ、ｆ）について説明する。

Here, correction values (a, b, c, d, e, f) set by the coordinate converter 10 will be described.

  The correction value is a coefficient based on the phase delay amount of each phase of the current sensor 7 and depends on the angular frequency (ω) of the motor 8. In the current sensor 7, a phase delay occurs in the detected current between the current sensors 7 of each phase due to variations in production. The phase delay affects each frequency of the motor 8.

  When there is no phase delay in each phase, the u, v, and w phase components with respect to the dq axis of the rotating coordinate system are expressed as sin (θ), sin (θ−120), sin (θ + 120). The

  And when the phase delay does not arise in each phase, when a three-phase two-phase conversion is represented by a determinant, it will be represented by Formula 4.

一方、各相で位相の遅れが生じている場合に、回転座標系のｄｑ軸に対する、ｕ、ｖ、ｗ相の成分は、ｓｉｎ（θ＋ｕ_ｄｌｙ）、ｓｉｎ（θ−１２０＋ｖ_ｄｌｙ）、ｓｉｎ（θ＋１２０＋ｗ_ｄｌｙ）で表される。ただし、ｕ_ｄｌｙ、ｖ_ｄｌｙ、ｗ_ｄｌｙ、は各相の位相の遅れ量（度）を示す。

On the other hand, when there is a phase delay in each phase, the components of the u, v, and w phases with respect to the dq axis of the rotating coordinate system are sin (θ + u _dly ), sin (θ−120 + v _dly ), sin (θ + 120 + w). _dly ). However, u _dly , v _dly , and w _dly indicate the phase delay amount (degree) of each phase.

  When the phase delay in each phase is not taken into consideration, the phase current of the dq axis of the rotating coordinate system can be calculated by performing the three-phase to two-phase conversion using Equation (4) as in the past. However, when a plurality of current sensors 7 are provided for each phase in order to detect the current of each phase, a phase delay occurs between the plurality of current sensors 7. Therefore, instead of using the transformation matrix shown in Expression (4) as it is, coefficients (correction values (a, b, c, d, e, f) based on the phase delay are used for each element of the transformation matrix of the three-phase / two-phase transformation. )) Is set, the phase current of the dq axis of the rotating coordinate system is calculated using Equation (3).

  Next, the process of deriving correction values (a, b, c, d, e, f) will be described.

First, u ₁ and U ₂ are coefficients for advancing u-phase current (i _u ) by an arbitrary phase, and V ₁ and V ₂ are coefficients for advancing v-phase current (i _v ) by an arbitrary phase. And W ₁ and W ₂ are coefficients for advancing the w-phase current (i _w ) by an arbitrary phase. The currents of the u, v, and w phases are expressed by the equations (5) to (7) with respect to the dq axis current in the rotating coordinate system.

そして、係数Ｕ_１、Ｕ_２、Ｖ_１、Ｖ_２、Ｗ_１、Ｗ_２により表される変換行列は、各相の位相の遅れ量（ｕ_ｄｌｙ、ｖ_ｄｌｙ、ｗ_ｄｌｙ）を用いて、式（８）により表される。

The transformation matrix represented by the coefficients U ₁ , U ₂ , V ₁ , V ₂ , W ₁ , W _{2 is} expressed by the equation using the phase delay amount (u _dly , v _dly , w _dly ) of each phase. It is represented by (8).

すなわち、下記式（９）により、ｕ、ｖ、ｗ相の相電流が、各相の位相の遅れ量（ｕ_ｄｌｙ、ｖ_ｄｌｙ、ｗ_ｄｌｙ）分、進むこととなる。

That is, according to the following formula (9), the phase currents of the u, v, and w phases advance by the phase delay amount (u _dly , v _dly , w _dly ) of each phase.

そして、式（９）の変換行列式を変形させることにより、本例における三相二相変換を表す式が導出され、各補正値（ａ、ｂ、ｃ、ｄ、ｅ、ｆ）が導出される。ここで、式（９）の変換行列式から、ｄｑ軸電流の式を導出するために、下記の式（１０）で示される行列を用意する。

Then, by transforming the transformation determinant of Equation (9), an equation representing the three-phase to two-phase transformation in this example is derived, and each correction value (a, b, c, d, e, f) is derived. The Here, in order to derive the dq-axis current equation from the transformation determinant of equation (9), a matrix represented by the following equation (10) is prepared.

また、式（１０）の逆行列である、下記の式（１１）及び式（１２）を用意する。

Also, the following formulas (11) and (12), which are inverse matrices of formula (10), are prepared.

式１０の行列の（１、１）要素、（１、２）要素、（２、１）要素、（２、２）要素、（３、１）要素、（３、２）要素は、式（９）の変換行列の各要素に相当する。そのため、式（１１）の（１、１）要素、（１、２）要素、（１、３）要素、（２、１）要素、（２、１）要素、（２、３）要素を抽出した行列を、式（９）の左側から乗算させることで、本例の三相二相変換を表す式が導出される。ゆえに、各補正値（ａ、ｂ、ｃ、ｄ、ｅ、ｆ）は、下記の式（１３）及び式（１４）により表される。

The (1,1) element, (1,2) element, (2,1) element, (2,2) element, (3,1) element, (3,2) element of the matrix of Expression 10 It corresponds to each element of the transformation matrix of 9). Therefore, (1,1) element, (1,2) element, (1,3) element, (2,1) element, (2,1) element, (2,3) element of formula (11) are extracted. By multiplying the matrix obtained from the left side of the equation (9), an equation representing the three-phase to two-phase transformation of this example is derived. Therefore, each correction value (a, b, c, d, e, f) is expressed by the following equations (13) and (14).

上記のように、位相遅れ量設定部１００は、回転数演算部１１より演算されたモータ８の角周波数（ω）に基づき、各相電流の位相遅れ量（ｕ_ｄｌｙ、ｖ_ｄｌｙ、ｗ_ｄｌｙ、）を設定する。そして、座標変換器１０は、当該位相遅れ量（ｕ_ｄｌｙ、ｖ_ｄｌｙ、ｗ_ｄｌｙ、）を用いて式（１３）により三相二相変換のための補正値（ａ、ｂ、ｃ、ｄ、ｅ、ｆ）を設定し、式（３）により固定座標系の各相の相電流を回転座標系の相電流に変換する。

As described above, the phase delay amount setting unit 100 is based on the angular frequency (ω) of the motor 8 calculated by the rotational speed calculation unit 11 and the phase delay amount (u _dly , v _dly , w _dly , ) Is set. Then, the coordinate converter 10 uses the phase delay amounts (u _dly , v _dly , w _dly ) to correct the correction values (a, b, c, d, e, f) are set, and the phase current of each phase of the fixed coordinate system is converted into the phase current of the rotating coordinate system by Equation (3).

The coordinate converter 10 stores a table shown in FIG. FIG. 2 is a diagram illustrating a table stored in the coordinate converter 10. As described above, the phase delay amount (u _dly , v _dly , w _dly ) of each phase depends on the angular frequency of the motor 8, and the correction values (a, b, c, d, e, f) are expressed by Equation (13). And the equation (14). Further, the phase lag of the current sensor 7 of each phase is a value fixed in advance due to variations in the production stage. Therefore, since each correction value (a, b, c, d, e, f) is uniquely determined with respect to the angular frequency (ω) of the motor 8, the coordinate converter 10 is based on, for example, a table shown in FIG. 2. The correction values (a, b, c, d, e, f) corresponding to the angular frequency (ω) of the motor 8 may be stored in advance. Then, the coordinate converter 10 refers to the table, sets correction values (a, b, c, d, e, f) corresponding to the angular frequency (ω) of the motor 8, and the above three-phase two-phase. Perform conversion. Thereby, the coordinate converter 10 can correct | amend the phase delay which arises in the current sensor 7 of each phase, and can perform three-phase two-phase conversion.

As described above, in this example, the phase lag amount (u _dly , v _dly , w _dly ) of the phase current of each phase is set by the phase lag amount setting unit 100, and the corresponding (u _dly , v _dly , w _dly )) and correction amounts (a, b, c, d, e, f) are set, and the correction values (a, b, c, d, e, f) are used to determine the fixed coordinate system. The phase current of each phase is converted into a current in a rotating coordinate system. As a result, when each of the three-phase currents is detected by the plurality of current sensors 7 and a phase lag occurs between the plurality of current sensors 7, this example corrects the phase lag and then corrects the phase lag. Conversion can be performed. As a result, when the inverter 6 is feedback controlled using a converter that performs three-phase to two-phase conversion, the inverter 6 can be accurately controlled.

Further, in this example, the coordinate converter 10 _changes the fixed coordinate system to the rotating coordinate system based on the phase lag amounts (u _dly , v _dly , w _dly ) of each phase set by the phase lag amount setting unit 100. Correction values (a, b, c, d, e, f) are set for each element to be converted, and the above conversion is performed. As a result, when each of the three-phase currents is detected by the plurality of current sensors 7 and a phase lag occurs between the plurality of current sensors 7, this example corrects the phase lag for each element, Since phase-to-phase conversion can be performed, the phase lag between the current sensors 7 can be corrected with higher accuracy.

  Here, the waveform of the dq-axis current (current after conversion) and the correction by the coordinate converter 10 of this example when the correction by the coordinate converter 10 of this example is performed using FIG. 3A and FIG. 3B. The waveform of the dq-axis current (the current after conversion) when not performing the above will be described. FIG. 3 a shows the waveform of the phase current that actually flows through each phase of the inverter 6 and the motor 8, and shows the waveform of the phase current detected by the current sensor 7. However, waveforms a1 to a3 in FIG. 3a indicate phase currents that actually flow through the u, v, and w phases, respectively, and waveforms b1 to b3 indicate phase currents that are detected in the u, v, and w phases. The waveforms c1 and c2 in FIG. 3b show the dq-axis current without correction, and the waveforms d1 and d2 in FIG. 3b show the dq-axis current with correction. 3A and 3B, the horizontal axis represents time, and the vertical axis represents the normalized current magnitude.

  As shown in FIG. 3a, the phase current that actually flows through each phase does not match the phase current detected by the current sensor 7, and it can be confirmed that there is a phase delay in each phase. As shown in FIG. 3b, it can be confirmed that the dq-axis current without pulsation pulsates, and the dq-axis current with correction pulsates. That is, as shown in FIG. 3b, according to this example, the pulsation of the dq-axis current after the three-phase to two-phase conversion can be corrected.

In this example, in the coordinate converter 10, the current in the fixed coordinate system before conversion is not necessarily converted to the current in the rotating coordinate system by multiplying the correction values (a, b, c, d, e, f). The correction value may be calculated after the three-phase to two-phase conversion. That is, the coordinate converter 10 sets a correction value along the coordinate system of the dq axis based on the phase lag amount (u _dly , v _dly , w _dly ) of each phase, and converts the rotation coordinate system after the conversion. The current is multiplied by the correction value. As a result, the dq-axis current equivalent to the current in the rotating coordinate system calculated by the equations (3), (13), and (14) is calculated.

  The inverter 6 corresponds to the “power conversion means” of the present invention, the current sensor 7 corresponds to the “current detection means”, the phase delay amount setting unit 100 corresponds to the “phase delay amount setting means”, and the coordinate converter 10 Corresponds to “coordinate conversion means”, and the rotation speed calculator 11 and the magnetic pole position detector 9 correspond to “rotation speed detection means”. The current voltage map 1, the current controller 2, the coordinate converter 3 and the PWM converter 4 correspond to the “control means” of the present invention.

<< Second Embodiment >>
FIG. 4 is a block diagram of the motor control device according to the embodiment of the invention. This example differs from the first embodiment described above in that the current sensor 7 is provided only in two phases of the U phase and the V phase. Since the configuration other than this is the same as that of the first embodiment described above, the description thereof is incorporated as appropriate.

The current sensors 7 are provided in the U phase and the V phase, respectively, and detect phase currents (i _u , i _v ). The detected phase current (i _u , i _v ) is input to the gain correction unit 13, and the gain correction unit 13 corrects the phase current (i _u , i _v ), and the phase current (i _{u_gain} , i _{v — gain} ) is output to the coordinate converter 10. The phase currents after correction (i _{u — gain} , i _{v — gain} ) are expressed by equation (15).

ｗ相の電流は、電流センサ７により検出されず、またゲイン補正部１３により補正されない。代わりに、座標変換器１０は、入力された補正後の相電流（ｉ_{ｕ＿ｇａｉｎ}、ｉ_{ｖ＿ｇａｉｎ}）に基づき、下記の式（１６）を用いて、ｗ相の相電流を算出する。

The w-phase current is not detected by the current sensor 7 and is not corrected by the gain correction unit 13. Instead, the coordinate converter 10 calculates the w-phase phase current using the following equation (16) based on the input phase currents after correction (i _{u — gain} , i _{v — gain} ).

座標変換器１０は、入力された補正後の相電流（ｉ_{ｕ＿ｇａｉｎ}、ｉ_{ｖ＿ｇａｉｎ}）と、式（１５）により算出された相電流（ｉ_{ｗ＿ｇａｉｎ}）とを、式（３）を用いて、固定座標系の相電流（ｉ_ｄ、ｉ_ｗ）に変換する。

The coordinate converter 10 uses the equation (3) to fix the input phase current after correction (i _{u_gain} , i _{v_gain} ) and the phase current (i _{w_gain} ) calculated by the equation (15) to the fixed coordinates. It converts into phase current ( _id , _iw ) of a system.

Here, correction values (a, b, c, d, e, f) set by the coordinate converter 10 will be described. Unlike the first embodiment, the w-phase current is not detected by the current sensor 7 in this example. Therefore, the phase delay amount of the w phase is calculated from the phase delay amounts (u _dly , v _dly ) of the u phase and the v phase. When there is a phase delay in each phase, the components of the u, v, and w phases with respect to the dq axis of the rotating coordinate system are sin (θ + u _dly ), sin (θ−120 + v _dly ), (−sin (Θ + u _dly ) + sin (θ−120 + v _dly )). That is, the w-phase component is represented by the amount of phase delay (u _dly , v _dly ).

  Basically, the correction values (a, b, c, d, e, f) of Expression (3) are derived by the same derivation process as in the first embodiment. However, since the current is not detected by the current sensor 7 for the w phase as described above, the correction value (17) to (21) are used instead of the equations (8) to (12). a, b, c, d, e, f) are derived.

そして、上記の導出工程により導きだされる、各補正値（ａ、ｂ、ｃ、ｄ、ｅ、ｆ）は、下記の式（２２）及び式（２３）により表される。

And each correction value (a, b, c, d, e, f) derived | led-out by said deriving process is represented by the following formula | equation (22) and Formula (23).

これにより、インバータ６とモータ８との相電流について、必ずしも全ての相の電流を電流センサ７により検出する必要はなく、少なくとも２相の相電流を検出すれば、本例による制御を行うことができる。なお、上記において、電流センサ７はｕ相及びｖ相のみの相電流をそれぞれ検出するが、ｗ相及びｕ相の相電流、又は、ｖ相及びｗ相の相電流を検出してもよい。

As a result, it is not always necessary to detect the currents of all phases of the phase currents of the inverter 6 and the motor 8 by the current sensor 7. If at least two phase currents are detected, the control according to this example can be performed. it can. In the above description, the current sensor 7 detects only the phase currents of the u phase and the v phase, respectively, but may detect the phase currents of the w phase and the u phase, or the phase currents of the v phase and the w phase.

As described above, in this example, at least two phase currents are detected by the current sensor 7, and the phase lag amount (u _dly , v _dly , w _dly ) of each phase is detected by the phase lag amount setting unit 100. The correction amount (a, b, c, d, e, f) is set by the coordinate converter 10 based on the (u _dly , v _dly , w _dly ), and the correction value (a, b, c) is set. , D, e, f) to convert the phase current of each phase of the fixed coordinate system into the current of the rotating coordinate system. Thereby, in this example, when at least two-phase currents are detected by the plurality of current sensors 7 and a phase lag occurs between the plurality of current sensors 7, the phase lag is corrected and the three-phase to two-phase conversion is performed. It can be performed. As a result, when the inverter 6 is feedback controlled using a converter that performs three-phase to two-phase conversion, the inverter 6 can be accurately controlled.

  Here, the waveform of the dq-axis current (current after conversion) and the correction by the coordinate converter 10 of this example when the correction by the coordinate converter 10 of this example is performed using FIGS. 5a and 5b. The waveform of the dq-axis current (the current after conversion) when not performing the above will be described. FIG. 5 a shows the waveform of the phase current that actually flows through each phase of the inverter 6 and the motor 8, and shows the waveform of the phase current detected by the current sensor 7. However, waveforms e1 to e3 in FIG. 5a indicate phase currents that actually flow through the u, v, and w phases, respectively, and waveforms f1 and f2 indicate phase currents that are detected in the u and v phases. Waveforms g1 and g2 in FIG. 5b show the dq-axis current without correction, and waveforms h1 and h2 in FIG. 5b show the dq-axis current with correction. 5A and 5B, the horizontal axis represents time, and the vertical axis represents the normalized current magnitude.

  As shown in FIG. 5a, the phase current that actually flows through each phase does not match the phase current detected by the current sensor 7, and it can be confirmed that there is a phase delay in each phase. Then, as shown in FIG. 5b, it can be confirmed that the dq-axis current without pulsation pulsates, and the pulsation is suppressed with the dq-axis current with correction. That is, as shown in FIG. 5b, according to this example, the pulsation of the dq-axis current after the three-phase to two-phase conversion can be corrected.

DESCRIPTION OF SYMBOLS 1 ... Current-voltage map 2 ... Current controller 3 ... Coordinate converter 4 ... PWM converter 5 ... Battery 6 ... Inverter 7 ... Current sensor 8 ... Motor 9 ... Magnetic pole position detector 10 ... Coordinate converter 11 ... Rotational speed calculator 12 ... LPF
13 ... Gain correction unit 100 ... Phase delay amount setting unit

Claims (5)

Power conversion means connected to the multiphase motor and converting DC power to AC power;
A plurality of current detection means for respectively detecting at least two phase currents of the multiphase motor;
Phase delay amount setting means for setting the phase delay amount of the phase current of each phase of the multiphase motor,
Coordinate conversion means for converting a phase current of the fixed coordinate system of each phase into a current of a rotating coordinate system, including the phase currents of the two phases detected by the plurality of current detection means;
Control means for controlling the power conversion means based on the current of the rotating coordinate system converted by the coordinate conversion means and an output target value of the multiphase motor input from the outside,
The coordinate conversion means includes
Setting a plurality of correction values corresponding to each phase based on the phase delay amount of each phase set by the phase delay amount setting means,
A motor control device that converts a phase current of the fixed coordinate system into a current of the rotating coordinate system using the plurality of correction values. The plurality of current detection means detect phase currents of all phases of the multiphase motor,
The motor control device according to claim 1, wherein the coordinate conversion means converts the phase current of the fixed coordinate system of all the phases into a current of the rotating coordinate system. The coordinate conversion means includes
2. The correction value is set for each element to be converted from the fixed coordinate system to the rotating coordinate system based on the phase delay amount of each phase set by the phase delay amount setting means. 2. The motor control device according to 2. A rotation speed detecting means for detecting the rotation speed of each phase motor;
4. The motor control device according to claim 1, wherein the phase delay amount setting unit sets the phase delay amount according to the number of rotations detected by the rotation detection unit. 5. . A current detection step of detecting at least two phase currents of the multiphase motor;
A phase delay amount setting step for setting the phase delay amount of the phase current of each phase of the multiphase motor;
A current conversion step of converting a phase current of the fixed coordinate system of each phase into a current of a rotating coordinate system, including the phase currents of the two phases detected by the current detection step;
Outputting a control signal based on the current of the rotating coordinate system converted by the current conversion step and an output target value of the multiphase motor input from the outside;
Converting DC power into AC power based on the control signal, and driving the multiphase motor with the AC power,
The current conversion step includes
Setting a plurality of correction values corresponding to each phase based on the phase delay amount of each phase set by the phase delay amount setting step;
A motor control method comprising: converting a phase current of the fixed coordinate system into a current of the rotating coordinate system using the plurality of correction values.

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