WO2021205690A1 - Power conversion device - Google Patents

Abstract

This power conversion device comprises a power converter having a switching element, and a control unit that controls the power converter to drive a motor. The control unit calculates a phase error estimated value, which is the deviation between the rotation phase value of the motor and a rotation phase estimated value, and calculates a q-axis inductance estimated value such that a component inversely proportional to the phase error estimated value follows a predetermined value.

Description

Power converter

The present invention relates to a power conversion device.

When driving a magnet motor with strong non-linear characteristics that depends on the current value, an estimation error may occur in the control phase due to a change in the q-axis inductance, causing the magnet motor to step out. A method for estimating the q-axis inductance of a permanent magnet motor is described in Patent Document 1. The permanent magnet motor is controlled so that torque fluctuation occurs, the estimated value of the magnetic pole position of the motor is obtained based on the estimated value of the current value and the q-axis inductance of the motor, and the fluctuation of the estimated value of the magnetic pole position caused by the torque fluctuation is obtained. Patent Document 1 discloses a technique for estimating the q-axis inductance based on the above.

JP 2015-195715

The technique of Patent Document 1 is premised on the occurrence of torque pulsation, and utilizes the phenomenon that torque fluctuation occurs in synchronization with the input voltage fluctuation of the inverter circuit.

However, when the capacitor capacity in the inverter circuit is large, the torque fluctuation becomes small, so it is difficult to estimate the q-axis inductance with the technique of Patent Document 1. Further, when the input voltage fluctuation is small, the q-axis inductance cannot be estimated with high accuracy by the technique of Patent Document 1.

If the q-axis inductance cannot be estimated with high accuracy, the phase error will become large and the motor operation will become unstable, and wasteful motor current will flow, resulting in inefficiency.

An object of the present invention is to provide a power conversion device capable of highly accurate estimation of q-axis inductance even if torque pulsation does not occur.

As a preferable example of the present invention, a power converter having a switching element and a control unit for controlling the power converter for driving a motor are provided.
The control unit
The phase error estimated value, which is the deviation between the rotational phase value of the motor and the rotational phase estimated value, is calculated, and the q-axis inductance estimated value is such that the component inversely proportional to the phase error estimated value follows the determined value. It is a power conversion device that calculates.

According to the present invention, it is possible to estimate the q-axis inductance with high accuracy.

The block diagram of the power conversion apparatus and the permanent magnet motor in Example 1 is shown. The block diagram of the phase error estimation part is shown. The block diagram of the q-axis inductance estimation calculation unit is shown. The figure which shows the control characteristic when the comparative example is used. The figure which shows the control characteristic at the time of using Example 1. FIG. The figure which shows the structure of the q-axis inductance estimation calculation part in the modification of Example 1. FIG. The figure which shows the structure for confirming the manifestation in Example 1. FIG. The figure which shows the structure of the power conversion apparatus and the permanent magnet motor in Example 2. FIG. The figure which shows the structure of the power conversion apparatus and the synchronous synchronous motor in Example 3. FIG. The figure which shows the structure of the power conversion apparatus and the permanent magnet motor in Example 4. FIG.

Hereinafter, examples will be described in detail using drawings.

FIG. 1 is a configuration diagram of a power conversion device and a permanent magnet motor according to the first embodiment. The permanent magnet motor 1 outputs a motor torque that is a combination of a torque component due to the magnetic flux of the permanent magnet and a torque component due to the inductance of the armature winding.

The power converter 2 includes a semiconductor element as a switching element. Power converter 2, the voltage command value of three-phase AC _{^{v u *, v v *,}} v enter a _w ^*, the voltage command value of three-phase AC _{^{v u *, v v *,}} v voltage proportional to _w ^* Is output. Based on the output of the power converter 2, the permanent magnet motor 1 is driven to change the voltage and the number of rotations of the permanent magnet motor 1. An IGBT (Insulated Gate Bipolar Transistor) may be used as the switching element.

The current detector 3 detects the three-phase alternating currents i _u , i _v , and i _w of the permanent magnet motor 1. In this embodiment, the current detector 3 is provided inside the power conversion device, but may be provided outside the power conversion device.

The control unit includes a coordinate conversion unit 4, a phase error estimation calculation unit 5, a frequency estimation calculation unit 6, a phase estimation calculation unit 7, a q-axis inductance estimation calculation unit 8, a speed control calculation unit 9, and a vector control calculation unit, which will be described below. 10. The coordinate conversion unit 11 is provided. Then, the control unit controls the power converter 2.

The control unit is composed of semiconductor integrated circuits (arithmetic control means) such as a microcomputer (microcomputer) and a DSP (Digital Signal Processor). Either or all of the control unit can be configured with hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

Next, each component of the control unit that controls the power converter 2 will be described.

The coordinate conversion unit 4 has the three-phase AC currents i _u , i _v , and i _w AC current detection values i _uc , i _vc , i _w c, and the rotation phase estimated value θ _{dc of the} power converter 2 to the current on the d-axis. The detected value i _dc and the q-axis current detected value i q _c are output.

The phase error estimation calculation unit 5 has a d-axis voltage command value v _dc ^** , a q-axis voltage command value v _qc ^** , an estimated q-axis inductance value L _q ^** , a frequency estimation value ω _r ^{^} , and d. Based on the axis current detection value i _dc , the q-axis current detection value i _qc , and the electrical circuit constant of the permanent magnet motor 1, the rotational phase estimated value θ _{dc of the} power converter 2 and the actual rotational phase value θ _d The estimation operation of the phase error Δθ, which is the deviation of, is executed. In this embodiment, in order to estimate the phase error based on the extended induced voltage, the phase error is estimated according to (Equation 5) described later, and the phase error estimated value Δθ _c is output.

The frequency estimation calculation unit 6 outputs the frequency estimation value ω _r ^{^} from the deviation between the phase error command value “0” (zero) and the phase error estimation value Δθ _{c. The frequency estimation calculation unit 6 controls ω r} ^{^} for the frequency estimation value so that the phase error is zero.

The phase estimation calculation unit 7 _{integrates the frequency estimation value ω r} ^{^} and outputs the _{rotation phase estimation value θ dc} to the coordinate conversion unit 4 and the coordinate conversion unit 11.

The q-axis inductance estimation calculation unit 8 uses the q-axis inductance estimation value L from _{the denominator component V and the frequency estimation value ω r} ^{^} calculated by the phase error estimation calculation unit 5 (Equation 5) and the d-axis current detection value i _{dc. q} ^** is calculated and output to the phase error estimation calculation unit 5 and the vector control calculation unit 10. Here, the case where the denominator component V of the phase error estimation calculation based on the extended induced voltage is used is described, but the component is not limited to the denominator component V as long as it is a component inversely proportional to _{the phase error estimated value Δθ c.}

The speed control calculation unit 9 outputs _{the current command value i q} ^* on the q-axis from the deviation between the _{frequency command value ω r} ^* and the frequency estimation value ω _r ^{^.}

The vector control calculation unit 10 uses the electric circuit constant of the permanent magnet motor 1, the d-axis current command value i _d ^{*, the} q-axis current command value i _q ^* , the d-axis current detection value i _dc, and the q-axis current detection. Based on the values i _qc , frequency estimate ω _r ^{^} , and q-axis inductance estimate L _q ^** , the d-axis voltage command value v _dc ^** and q-axis voltage command value v _qc ^** are output, and the power is output. The frequency and voltage of the converter 2 are controlled.

The coordinate conversion unit 11 has a voltage command value v _dc ^{** on} the d-axis, a voltage command value v _qc ^{** on the} _{q-axis, and a voltage command value v u} ^* , v _v ^* , for three-phase AC from the rotation phase estimation value θ _dc. v Output _w ^*.

The DC power supply 20 supplies a DC voltage and a DC current to the power converter 2.

First, the basic operation of the position sensorless vector control method when the q-axis inductance estimation calculation unit 8 is used will be described.

The speed control calculation unit 9 performs the _{q-axis current command value i q,} which is a torque current command according to (Equation 1) by proportional control and integral control so that the frequency estimated value ω _r ^{^} _{follows the frequency command value ω r} ^*. Calculate ^*.

ここで、K_spは速度制御の比例ゲイン、K_siは速度制御の積分ゲインである。

Here, K _sp is the proportional gain of speed control, and K _si is the integrated gain of speed control.

First, the vector control calculation unit 10 sets the resistance set value R ^* which is the electric circuit constant of the permanent magnet motor 1, the d-axis inductance set value L _d ^*, and the q-axis inductance estimated value L _q ^** . the set value of the induced voltage coefficient K _e ^*, the current command value of the d-axis i _d ^* current command value and the q-axis i _q ^*, and using the frequency estimate omega _r ^{^,} the voltage of the d-axis in accordance with equation (2) Outputs the reference value v _dc ^* and the q-axis voltage reference value v _qc ^*.

ここで、T_acrは電流制御の応答時定数、ｓはラプラス演算子である（以下の数式でも同様である）。

Here, T _acr is the response time constant of current control, and s is the Laplace operator (the same applies to the following formula).

Secondly, the vector control calculation unit 10 sets the d-axis current command value i _d ^* and the q-axis current command value i _q ^* to the d-axis current detection values i _dc and q-axis current detection of each component. _{The d-axis voltage correction value Δv dc} and the q-axis voltage correction value Δv _qc are calculated according to (Equation 3) by proportional control and integral control so that the value i _{qc follows.} Here, K _pd is the proportional gain of d-axis current control, K _id is the integral gain of d-axis current control, K _pq is the proportional gain _{of q-axis current control, and K iq} is the integral gain of q-axis current control. Is.

_{Further, according to (Equation} 4), the voltage command value v _dc ^{** on} the d-axis and the voltage command value v ^{qc **} on the q-axis are calculated.

The phase error estimation calculation unit 5 has a d-axis voltage command value v _dc ^** , a q-axis voltage command value v _qc ^** , a d-axis current detection value i _dc , a q-axis current detection value i _qc , and a permanent magnet. The phase error estimated value Δθc is calculated according to (Equation 5) based on the electric circuit constant of the motor 1, the q-axis inductance estimated value, and the frequency estimated value ω _r ^{^.} _{The frequency estimation calculation unit 6 calculates the frequency estimation value ω r} ^{^} according to (Equation 6) based on the phase error estimation value Δθc. The phase estimation calculation unit 7 calculates the _{rotation phase estimation value θ dc} according to (Equation 7) based on the _{frequency estimation value ω r} ^{^} .

ここで、Kp_pllはPLL制御の比例ゲイン、Ki_pllはPLL制御の積分ゲインである。

Here, Kp _pll is the proportional gain of the PLL control, and Ki _pll is the integral gain of the PLL control.

FIG. 2 shows a block diagram of the phase error estimation calculation unit 5 in the first embodiment.
The phase error estimation calculation unit 5 calculates the phase error estimation value Δθ _{c according} to (Equation 5), and outputs the denominator component V in the calculation formula of the phase error estimation value Δθ _c together with the phase error estimation value Δθ _c.

FIG. 3 shows a block diagram of the q-axis inductance estimation calculation unit 8 in the first embodiment. The predetermined value calculation unit 8a uses the frequency estimation value ω _r ^{^} , the d-axis current detection value i _{dc , the set value K e} ^* of the induced voltage coefficient of the permanent magnet motor, the d-axis inductance set value L _d ^*, and the q-axis. Using the estimated inductance value L _q ^** , calculate the predetermined value V ^{* according} to (Equation 8).

The PI control unit 8b has P (proportional) + I (proportional) shown in (Equation 9) so that the denominator component V, which is the output of the phase error estimation calculation unit 5 ^{, follows the predetermined value V * calculated in (Equation 8).} (Integral) control is performed, and the correction value ΔL _q ^* of the q-axis inductance is calculated.

ここで、Kp_LqはL_q推定の比例ゲイン、Ki_LqはL_q推定の積分ゲインである。

Here, Kp _Lq is a proportional gain, Ki _Lq of L _q estimation is an integral gain of L _q estimated.

The addition unit 8d adds the constant L _q ^* , which is the initial value 8c of the q-axis inductance, and the correction value ΔL _q ^* of the q-axis inductance, and according to (Equation 10), the new estimated value L _q ^{** of the q-axis inductance.} Is output.

Next, the principle of stable and highly efficient operation of this embodiment will be described. FIG. 4 shows the control characteristics when the q-axis inductance estimation calculation unit 8 of this embodiment is not used (ΔL _q ^* = 0), that is, as a comparative example.

The formula for the d-axis voltage command value v _dc ^** and the q-axis voltage command value v _qc ^** shown in (Equation 2) is used, and the formula for the estimated phase error Δθ _{c shown in (Equation 5).} This is the simulation result when the _{estimated value L q} ^** of the q-axis inductance included in is + 20% error with respect to the true L _q.

Figure 4 is the giving ramp load torque from point A shown in the figure, and the denominator component V of the phase error estimating arithmetic unit 5 at that time, the current i _d of d-axis of the permanent magnet motor 1, and q-axis The current i _{q of} is displayed.

At point B in FIG. 4, as the denominator component V decreases, the d-axis current i _d and the q-axis current i _q increase, and the d-axis current i _d , which should be almost constant, increases and increases. _{The current i q on} the q-axis, which should be supposed to be, suddenly decreases, and the permanent magnet motor is out of step. Here, step-out refers to a state in which the synchronization of the command input for controlling the motor and the rotation of the motor is lost.

That is, the magnet motor may step out depending on the magnitude of the set value L _q ^{* of the q-axis inductance.} _{When the set value L q} ^* of the q-axis inductance and the actual L _q match L _q ^* = L _q , the magnitude V of the denominator component is (Equation 11).

However, when L _q ^* ≠ L _q , the magnitude V of the denominator component is (Equation 12).

Here, K _e is the actual value of the induced voltage coefficient of the permanent magnet motor, [Delta] [theta] is the actual phase error, L _d is the actual d-axis inductance, L _q is the actual q-axis inductance, L _q ^* is the q-axis inductance This is the set value of.
_{In (Equation} 12), when Δθ is “negative”, the 1/2 (L _{d −} L _q ) (−i qc sin 2 Δθ) component in (Equation 12) acts on the side that reduces the _{K e cos Δθ component.}

Therefore, in this embodiment, the denominator component V of the phase error estimation calculation unit is the frequency estimation value ω _r ^, the d-axis current detection value i _dc, and the induced voltage of the permanent magnet motor, which is the electric circuit constant of the permanent magnet motor. ^{Follows the predetermined value V *} (predetermined voltage value) calculated from (Equation 8) using the set value K _e ^{* of} the coefficient, the set value L ^{d * of} _{the d-} axis inductance, and the estimated value L _q ^{** of the q-axis inductance.} Therefore, the estimated value L _q ^** of the q-axis inductance is calculated from (Equation 10).

That is, the denominator component is calculated by calculating _{the estimated value L q} ^** of the q-axis inductance so that the denominator component V in the calculation formula of the phase error estimated value Δθ _c ^{follows the ideal predetermined value V * (Equation 8).} Controls V.

Further, by using the calculated estimated value L _q ^** of the q-axis inductance for the input of the vector control calculation unit 10 and the phase error estimation calculation unit 5, stable and highly efficient operation can be realized.

The control characteristics in this embodiment are shown in FIG. The same load torque as in FIG. 4 is applied from point A. q-axis inductance estimation computation unit starts estimation of the q-axis inductance L _q in point c, is the ratio between the actual q-axis inductance L _q and q-axis inductance estimate ^{_{L q ** L q ** / L}} q Is almost 1.0 at point D.

Since the q-axis inductance L _q is estimated with high accuracy (L _q ^** ≒ L _q ), the vibration of the d-axis current i _d and the q-axis current i _q and the step-out of the permanent magnet motor did not occur. It can be seen that the effect of the example is clear.

Further, in the above embodiment, in the q-axis inductance estimation calculation unit 8, the proportional control Kp _Lq and the integral control gain Ki _Lq are fixed values, but as shown in FIG. 6, the frequency estimation values ω _r ^{^} and the d-axis It may be changed according to the current detection value i _dc.

The q-axis inductance estimation calculation unit 81 in FIG. 6 corresponds to the q-axis inductance estimation calculation unit 8 in FIGS. 1 and 3. The predetermined value calculation unit 81a and the initial value L _q ^* 81c of the q-axis inductance and the addition unit 81d in FIG. 6 are the same as the predetermined value calculation unit 8a and the initial value L _q ^* 8c of the q-axis inductance and the addition unit 8d of FIG. Is.

In the PI control unit 81b, the phase error estimation calculation unit 5 changes the gains of the proportional control and the integral control substantially in proportion to the magnitude _{of the frequency estimation value ω r} ^{^} and the d-axis current detection value i _dc. The denominator component V ^{changes to its predetermined value V * according} to the frequency and current value. Highly accurate estimation of q-axis inductance L _q can be realized in a shorter time.

Here, a verification method when this embodiment is adopted will be described with reference to FIG. 7. A voltage detector 22 and a current detector 23 are attached to the power conversion device 21 that drives the permanent magnet motor 1, and an encoder 24 is attached to the shaft of the permanent magnet motor 1.

_{The vector voltage / current component calculation unit 25 contains the voltage detection values (v uc} , v _vc , v _wc ) of the pseudo three-phase AC, which are the outputs of the voltage detector 22 and the current detector 23, and the current of the three-phase AC. The detected values (i _uc , i _vc , i _wc ) and the position θ which is the output of the encoder are input, and the position θ is differentiated from the _{vector voltage components v dcc} and v _qcc and the vector current components i _dcc and i _qcc. Calculate the detected value ω _r. In the observation unit 26 of the waveform of each unit, the estimated value Δθ _cc of the phase error is calculated by using (Equation 13).

_{Even if the magnitude of the q-axis inductance L q} ^* set in the power conversion device 21 is changed, if the denominator component shown in (Equation 13) is constant, it is clear that this embodiment is adopted.

According to the first embodiment, it is possible to realize a power conversion device capable of estimating the q-axis inductance with high accuracy. Further, since the q-axis inductance can be estimated with high accuracy, stable and highly efficient motor operation can be realized.

FIG. 8 is a diagram showing a configuration of the power conversion device of the second embodiment and the permanent magnet motor 1. In the first embodiment, the q-axis inductance was estimated during the actual operation, and the estimated value of the q-axis inductance was used for the vector control calculation unit 10 and the phase error estimation calculation unit 5. In the second embodiment, the q-axis inductance table reference unit 12 creates a correspondence table that records the correspondence between _{the q-axis current detection value i qc} and the q-axis inductance estimated value L _q ^{**, and from the next startup.} Sets the q-axis inductance estimate L _q ^{** from the created table.}

In FIG. 8, the components are a permanent magnet motor 1, a power converter 2, a current detector 3, a coordinate conversion unit 4, a phase error estimation calculation unit 5, a frequency estimation calculation unit 6, a phase estimation calculation unit 7, and a q-axis inductance estimation. The calculation unit 8, the speed control calculation unit 9, the vector control calculation unit 10, the coordinate conversion unit 11, and the DC power supply 20 are the same as those in FIG. In addition to the processing units listed in the first embodiment, the control unit has a q-axis inductance table reference unit 12 and a selection switch SW13 in the second embodiment.

The q-axis inductance table reference unit 12 _{inputs the q-axis current detection value i qc} and outputs the q-axis inductance estimated value L _q ^** . Selection switch SW13 is the output of the q-axis inductance estimation calculation unit 8 when the input value is "0", the output of the q-axis inductance table reference unit 12 when the input value is "1", the q-axis inductance estimate L _q Output as ^**.

When the selection switch SW13 executes the q-axis inductance estimation calculation unit 8 when the input value is “0”, _{the relationship between the q-axis current detection value i qc} and the q-axis inductance estimation value L _q ^** is in actual operation. It is created and saved as a corresponding table.

From the next startup execution, the input value of the selection switch SW13 is set from "0" to "1", and the q-axis inductance table reference unit 12 detects the q-axis current in the corresponding table from the q-axis current detection value. The q-axis inductance estimated value L _q ^** corresponding to the value may be read out.

According to this embodiment, the q-axis inductance estimated value L _q ^** changes according to the q-axis current value, so that highly efficient operation can be quickly realized.

Alternatively, when the estimated q-axis inductance value in the entire operating region can be grasped, the input value of the selection switch SW13 is set from "0" to "1", and the estimated q-axis inductance value L _q ^** is obtained from the created table. However, it may be set in the internal memory of the microcomputer mounted in the power converter.

According to the second embodiment, by acquiring the q-axis inductance estimated value from the corresponding table described above, it is possible to obtain a highly accurate q-axis inductance estimated value even when the q-axis inductance is not estimated during actual operation. Further, since the q-axis inductance can be estimated with high accuracy, stable and highly efficient motor operation can be realized.

FIG. 9 shows a configuration diagram of the power conversion device and the synchronous reluctance motor 1a of the third embodiment. In the first and second embodiments, the power conversion device for driving the permanent magnet motor has been used, but this embodiment relates to the power conversion device for driving the synchronous reluctance motor 1a.

In FIG. 9, the component power converter 2, current detector 3, coordinate conversion unit 4, phase error estimation calculation unit 5, frequency estimation calculation unit 6, phase estimation calculation unit 7, q-axis inductance estimation calculation unit 8, speed. The control calculation unit 9, the vector control calculation unit 10, the coordinate conversion unit 11, and the DC power supply 20 are the same as those in FIG. The control unit is the same as that of the second embodiment.

The permanent magnet motor embeds a permanent magnet in the rotor, but the synchronous reluctance motor 1a does not have a permanent magnet, and a current magnetic flux due to salient pole can be obtained by a cavity (flux barrier) provided in the rotor.

_{When the estimated value Δθ c} of the phase error is calculated by the equation (Equation 5), the denominator component includes the voltage information due to the salient polarity. Therefore, if the predetermined value calculation unit calculates a predetermined voltage value V ^{** according} to (Equation 14), the same control as that of the permanent magnet motor can be realized.

According to the third embodiment, it is possible to realize a power conversion device capable of estimating the q-axis inductance with high accuracy. Further, since the q-axis inductance can be estimated with high accuracy, stable and highly efficient operation can be realized even for the synchronous reluctance motor 1a.

FIG. 10 is a configuration diagram of a drive system of a permanent magnet motor having a power conversion device of the fourth embodiment, a permanent magnet motor 1, and a terminal.

Example 4 applies Example 2 to the drive system of the permanent magnet motor. In FIG. 10, the permanent magnet motor 1, the coordinate conversion unit 4, the phase error estimation calculation unit 5, the frequency estimation calculation unit 6, the phase estimation calculation unit 7, the q-axis inductance estimation calculation unit 8, the speed control calculation unit 9, and so on. The vector control calculation unit 10, the coordinate conversion unit 11, the q-axis inductance table reference unit 12, and the selection switch SW13 are the same as those in FIG. The control unit is the same as that of the second embodiment.

The permanent magnet motor 1, which is a component of FIG. 10, is driven by the power conversion device 21. The power conversion device 21 includes a coordinate conversion unit 4 in FIG. 8, a phase error estimation calculation unit 5, a frequency estimation calculation unit 6, a phase estimation calculation unit 7, a q-axis inductance estimation calculation unit 8, a speed control calculation unit 9, and a vector control calculation. The unit 10, the coordinate conversion unit 11, the q-axis inductance table reference unit 12, and the selection switch SW13 are implemented as software 20a, that is, a program.

Further, the power converter 2 in FIG. 8, the current detector 3, the DC power supply 20, and a CPU (not shown) that constitutes a control unit are mounted as hardware. The CPU executes the above program.

The control unit of the power conversion device calculates the q-axis inductance estimated value by the q-axis inductance estimation calculation unit 8, or the q-axis inductance estimated value from the relationship table in which the q-axis current detection value and the q-axis inductance estimated value are recorded. It has a selection switch SW13 for selecting whether to acquire. Further, a value of 0 or 1, which is an input value for switching the selection switch SW13, is set in the internal memory of the microcomputer.

Further, the input value of the selection switch SW13 of the software 20a can be set or changed by a higher-level device such as a digital operator 20b, a personal computer 27, a tablet 28, or a smartphone 29.

In this embodiment, the case of driving a permanent magnet motor is shown as an example, but even if this embodiment is applied not only to a permanent magnet motor but also to a synchronous synchronous motor drive system, highly efficient operation in position sensorless vector control is performed. Can be realized.

Further, the input value to the selection switch SW13 may be set on the fieldbus of the programmable logic controller, the local area network connected to the computer, or the control device.

In Examples 1 to 4 so far, the d-axis current command value i _d ^* , the q-axis current command value i _q ^* , the d-axis current detection value i _dc , and the q-axis current detection value i _Create d-axis voltage correction values Δv _dc and q-axis voltage correction values Δv _{qc from qc,} and add these voltage correction values and vector control voltage reference values v _dc ^* and v _qc ^* (Equation 4). The calculation was performed.

Other calculation methods include d-axis current command value i _d ^* , q-axis current command value i _q ^* , d-axis current detection value i _dc , and q-axis current detection value i q _c to vector control calculation. Create the intermediate d-axis current command value i _d ^** and q-axis current command value i _q ^** shown in (Equation 15), and make the frequency estimate ω _r ^ and the electric circuit of the permanent magnet motor 1. _{The vector control operation shown in (Equation} 16) is performed using the constant to calculate the second voltage command value v _dc ^{*** on} the d-axis and the second voltage command value v ^{qc ***} on the q-axis. You may.

Here, K _pd1 is the proportional gain of the d-axis current control, K _id1 is the integrated gain of the d-axis current control, K _pq1 is the proportional gain _{of the q-axis current control, and K iq1} is the integrated gain of the q-axis current control. , T _d is the electrical time constant of the d-axis (L _d ^* / R ^* ), and T _q : is the electrical time constant of the axis (L _q ^* / R ^* ).

Alternatively, from the d-axis current command value i _d ^* , the q-axis current command value i _q ^* , the d-axis current detection value i _dc , and the q-axis current detection value i _qc , the d-axis used for the vector control calculation Voltage correction value of proportional calculation component Δv _{d_p} ^* , voltage correction value of d-axis integration calculation component Δv _{d_i} ^* , voltage correction value of q-axis proportional calculation component Δv _{q_p} ^* , voltage correction value of q-axis integration calculation component Δv _{Create q_i} ^* by (Equation 17). Then, the vector control calculation shown in (Equation 18) using the frequency estimation value ω _r ^{^} and the electric circuit constant of the permanent magnet motor 1 is performed, and the third voltage command value of the d-axis v _dc ^**** and the q-axis are performed. The third voltage command value v _qc ^**** may be calculated.

ここで、K_pd2はｄ軸の電流制御の比例ゲイン、K_id2はｄ軸の電流制御の積分ゲイン、K_pq2はｑ軸の電流制御の比例ゲイン、K_iq2はｑ軸の電流制御の積分ゲインである。

Here, K _pd2 is the proportional gain of d-axis current control, K _id2 is the integral gain of d-axis current control, K _pq2 is the proportional gain _{of q-axis current control, and K iq2} is the integral gain of q-axis current control. Is.

Further, the d-axis current command value i _d ^{*, the} q-axis current detection value i _qc primary delay signal i _qctd , the frequency command value ω _r ^*, and the electric circuit constant of the permanent magnet motor 1 are shown in (Equation 19). A vector control operation may be performed to calculate the fourth voltage command value v _dc ^{***** on} the d-axis and the fourth voltage command value v _qc ^***** on the q-axis.

ここで、i_qctdはi_qcを一次遅れフィルタに通した信号である。

Here, i _qctd is _{a signal that has passed i qc} through a first-order lag filter.

In the first to third embodiments 1 to 3, even if the switching element constituting the power converter 2 is a Si (silicon) semiconductor element, it may be SiC (silicon carbide) or GaN (gallum). It may be a wide bandgap semiconductor device such as nitride).

1 ... Permanent magnet motor, 1a ... Synchronous reluctance motor, 2 ... Power converter, 3 ... Current detector, 4 ... Coordinate conversion unit, 5 ... Phase error estimation calculation unit, 6 ... Frequency estimation calculation unit, 7 ... Phase estimation calculation Unit, 8 ... q-axis inductance estimation calculation unit, 9 ... speed control calculation unit, 10 ... vector control calculation unit,
11 ... Coordinate conversion unit, 12 ... q-axis inductance table reference unit, 13 ... Switch, 20 ... DC power supply, 21 ... Power conversion device

Claims (12)

A power converter with a switching element and
It has a control unit that controls the power converter that drives the motor.
The control unit
A phase error estimated value, which is a deviation between the rotational phase value of the motor and the rotational phase estimated value, is calculated.
A power conversion device that calculates a q-axis inductance estimated value so that a component inversely proportional to the phase error estimated value follows a predetermined value. In the power conversion device according to claim 1,
The control unit
A power conversion device having a phase estimation calculation unit that calculates the rotation phase estimation value from a frequency estimation value. In the power conversion device according to claim 1,
The control unit
A power conversion device having a vector control calculation unit that controls the frequency and voltage of the power converter. In the power conversion device according to claim 1,
The control unit
A power conversion device having a frequency estimation calculation unit that controls a frequency estimation value so that the phase error becomes zero. In the power conversion device according to claim 1,
The control unit
It has a q-axis inductance estimation calculation unit that calculates the predetermined value from the frequency estimation value, the d-axis current detection value, the induced voltage coefficient of the motor, the d-axis inductance, and the q-axis inductance estimated value. Power converter. In the power conversion device according to claim 1,
The motor is a power conversion device that is a permanent magnet motor or a synchronous reluctance motor. In the power conversion device according to claim 1,
The control unit
From the d-axis voltage command value, the q-axis voltage command value, the q-axis inductance estimated value, the frequency estimated value, the d-axis current detected value, the q-axis current detected value, and the electric circuit constant of the motor, the phase A power conversion device having a phase error estimation calculation unit for calculating an error estimation value. In the power conversion device according to claim 1,
The component that is inversely proportional to the phase error estimation value is a power conversion device that is a denominator component of the calculation formula for phase error estimation. In the power conversion device according to claim 5,
The q-axis inductance estimation calculation unit
A power conversion device that changes the gain of proportional control and integral control according to the frequency estimation value or the d-axis current detection value. In the power conversion device according to claim 1,
The control unit
Create a relationship table between the q-axis current detection value and the q-axis inductance estimated value.
A power conversion device having a q-axis inductance table reference unit that acquires the q-axis inductance estimated value from the q-axis current detection value and the relation table. In the power conversion device according to claim 1,
The control unit
After creating the relationship table between the q-axis current detected value and the q-axis inductance estimated value,
A power conversion device that acquires the q-axis inductance estimated value from the relation table without calculating the q-axis inductance estimated value. In the power conversion device according to claim 1,
The control unit
Calculate the q-axis inductance estimate or
It has a switch for selecting whether to acquire the q-axis inductance estimated value from the relationship table between the q-axis current detected value and the q-axis inductance estimated value.
The input value for switching the switch is set in the memory and
A power conversion device that connects a digital operator, a personal computer, a tablet, or a smartphone device to set or change the input value.

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