JP7368302B2 - power converter - Google Patents

Description

The present invention relates to a power conversion device.

When driving a magnet motor that has strong nonlinear characteristics that depend on the current value, an estimation error may occur in the control phase due to a change in the q-axis inductance, and the magnet motor may lose synchronization. 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, and the estimated value of the motor's magnetic pole position is determined based on the motor current value and the estimated value of the q-axis inductance, and the fluctuation in the estimated value of the magnetic pole position caused by the torque fluctuation is calculated. Patent Document 1 discloses a technique for estimating the q-axis inductance based on .

JP2015-195715

The technique disclosed in Patent Document 1 is based on the premise that torque pulsations occur, and utilizes the phenomenon in which torque fluctuations occur in synchronization with input voltage fluctuations of an 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 using the technique of Patent Document 1. Further, when the input voltage fluctuation is small, the technique of Patent Document 1 cannot estimate the q-axis inductance with high accuracy.

If the q-axis inductance cannot be estimated with high accuracy, the problem arises that the phase error becomes large and the motor operation becomes unstable, and that efficiency deteriorates due to the flow of wasteful motor current.

An object of the present invention is to provide a power conversion device that can realize highly accurate estimation of q-axis inductance even without torque pulsation.

A preferred example of the present invention includes a power converter having a switching element and a control unit that controls the power converter that drives a motor,
The control unit includes:
An estimated phase error value, which is the deviation between the rotational phase value of the motor and the estimated rotational phase value, is calculated, and the estimated q-axis inductance value is adjusted so that a component that is inversely proportional to the estimated phase error value follows a predetermined value. This is a power conversion device that calculates

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

1 shows a configuration diagram of a power conversion device and a permanent magnet motor in Example 1. FIG. A block diagram of a phase error estimator is shown. A block diagram of a q-axis inductance estimation calculation section is shown. FIG. 7 is a diagram showing control characteristics when using a comparative example. FIG. 3 is a diagram showing control characteristics when using Example 1. FIG. 3 is a diagram showing the configuration of a q-axis inductance estimation calculation section in a modification of the first embodiment. FIG. 3 is a diagram showing a configuration for confirming conspicuousness in Example 1. FIG. 3 is a diagram showing the configuration of a power conversion device and a permanent magnet motor in Example 2. FIG. 7 is a diagram showing the configuration of a power conversion device and a synchronous motor in Example 3. FIG. 7 is a diagram showing the configuration of a power conversion device and a permanent magnet motor in Example 4.

Hereinafter, embodiments will be described in detail using the drawings.

FIG. 1 is a configuration diagram of a power conversion device and a permanent magnet motor in Example 1. 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.

Power converter 2 includes a semiconductor element as a switching element. The power converter 2 inputs three-phase AC voltage command values v _u ^* , v _v ^* , v _w ^*, and generates a voltage proportional to the three-phase AC voltage command values v _u ^* , v _v ^* , v _w ^*. Output. The permanent magnet motor 1 is driven based on the output of the power converter 2, and the voltage and rotation speed of the permanent magnet motor 1 are varied. An IGBT (Insulated Gate Bipolar Transistor) may be used as the switching element.

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

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, a coordinate conversion section 11 is provided. The control unit then controls the power converter 2.

The control section is constituted by a semiconductor integrated circuit (arithmetic control means) such as a microcomputer and a DSP (Digital Signal Processor). Either or all of the control section 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 section that controls the power converter 2 will be explained.

The coordinate conversion unit 4 converts the d-axis current from the detected alternating current values i _uc , i _vc , i _wc of the three-phase alternating currents i _u , i _v , i _w and the estimated rotational phase value θ _dc of the power converter 2. The detected value i _dc and the q-axis current detected value i _qc are output.

The phase error estimation calculation unit 5 calculates the d-axis voltage command value v _dc ^** , the q-axis voltage command value v _qc ^** , the estimated q-axis inductance value L _q ^** , the frequency estimated value ω _r ^{^} , d Based on the shaft current detection value i _dc , the q-axis current detection value i _qc , and the electric circuit constants of the permanent magnet motor 1, the estimated rotational phase value θ _dc and the actual rotational phase value θ _d of the power converter 2 are determined. An estimation calculation of the phase error Δθ, which is the deviation of the phase error Δθ, is performed. 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 estimated phase error value Δθ _c is output.

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

The phase estimation calculation unit 7 integrates the frequency estimated value ω _r ^{^} and outputs the rotational phase estimated value θ _dc to the coordinate transformation unit 4 and the coordinate transformation unit 11.

The q-axis inductance estimation calculation unit 8 calculates the q-axis inductance estimation value L from the denominator component V of (Equation 5) calculated by the phase error estimation calculation unit 5, the frequency estimation value ω _r ^{^} , and the d-axis current detection value i _dc . _q ^** is calculated and output to the phase error estimation calculation section 5 and the vector control calculation section 10. Although a case is described here in which the denominator component V of the phase error estimation calculation based on the extended induced voltage is used, the denominator component V is not limited to any component that is inversely proportional to the phase error estimated value Δθ _c .

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

The vector control calculation unit 10 calculates the electrical circuit constants 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 value. Based on the value i _qc , the estimated frequency value ω _r ^{^} , and the estimated q-axis inductance value L _q ^** , the d-axis voltage command value v _dc ^** and the q-axis voltage command value v _qc ^** are output, and the power Control the frequency and voltage of converter 2.

_The coordinate _conversion unit 11 converts three-phase AC ^voltage command values v _u ^* , _{v v} ^{* ,} Output v _w ^* .

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

First, the basic operation of the position sensorless vector control method when using the q-axis inductance estimation calculation section 8 will be explained.

The speed control calculation unit 9 calculates the q-axis current command value i ^q which is the 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 integral gain of speed control.

The vector control calculation unit 10 first calculates a resistance setting value R ^* , which is an electric circuit constant of the permanent magnet motor 1, a d-axis inductance setting value _Ld ^* , and an estimated value of the q-axis inductance _Lq ^**. Using the set value of the induced voltage coefficient K _e ^* , the d-axis current command value i _d ^* , the q-axis current command value i _q ^* , and the estimated frequency value ω _r ^{^} , the d-axis voltage is calculated according to (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 a response time constant of current control, and s is a Laplace operator (the same applies to the following formulas).

The vector control calculation unit 10 secondly calculates the d-axis current detection value i _dc and the q-axis current detection ^value of each component to the d-axis current command value i _d * and the q-axis current command value i _q ^* . The d-axis voltage correction value Δv _dc and the q-axis voltage correction value Δv _qc are calculated according to (Equation 3) using 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. It is.

Further, according to Equation 4, the d-axis voltage command value v _dc ^** and the q-axis voltage command value v _qc ^** are calculated.

The phase error estimation calculation unit 5 calculates 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. Based on the electric circuit constant of the motor 1, the estimated q-axis inductance value, and the estimated frequency value ω _r ^{^} , the estimated phase error value Δθc is calculated according to (Equation 5). 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 rotational 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 a proportional gain of PLL control, and Ki _pll is an integral gain of 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 using (Equation 5), and outputs the denominator component V in the calculation formula of the phase error estimation value Δθ _c as well as 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 calculates the estimated frequency value ω _r ^{^} , the detected d-axis current value i _dc , the set value K _e ^* of the induced voltage coefficient of the permanent magnet motor, the set value L _d ^* of the d-axis inductance, and the d-axis current detected value i dc . Using the estimated inductance value L _q ^** , a predetermined value V ^* is calculated according to (Equation 8).

The PI control unit 8b sets P (proportional) + ^I ( shown in (Equation 9) (integral) control and calculate the correction value ΔL _q ^* of the q-axis inductance.

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 the proportional gain of L _q estimation, and Ki _Lq is the integral gain of L _q estimation.

The adding 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 obtains a new estimated value of the q-axis inductance L _q ^** according to (Equation 10). Output.

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

In addition to using the equations for the d-axis voltage command value v _dc ^** and the q-axis voltage command value v _qc ^** shown in (Equation 2), the equation for the estimated phase error value Δθ _c shown in (Equation 5) is used. These are simulation results when the estimated value L _q ^** of the q-axis inductance included in the equation has an error of +20% with respect to the true L _q .

In FIG. 4, a ramp-like load torque is applied from point A shown in the figure, and at that time, the denominator component V of the phase error estimation calculation unit 5, the d-axis current i _d of the permanent magnet motor 1, and the q-axis The current i _q is displayed.

At point B in Figure 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 approximately constant, increases. The expected q-axis current _iq suddenly decreased, and the permanent magnet motor went out of step. Here, "step-out" refers to a state in which the command input for controlling the motor and the rotation of the motor are out of synchronization.

In other words, depending on the magnitude of the set value L _q ^* of the q-axis inductance, the magnet motor may step out. When L _q ^* =L _q , where the set value L _q ^* of the q-axis inductance and the actual L _q match, the magnitude V of the denominator component becomes (Equation 11).

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

where K _e is the actual value of the induced voltage coefficient of the permanent magnet motor, Δθ is the actual phase error, L _d is the actual d-axis inductance, L _q is the actual q-axis inductance, and L _q ^* is the q-axis inductance. This is the setting value.
In (Equation 12), when Δθ is “negative”, the 1/2(L _d −L _q )(−i _qc sin2Δθ) component in (Equation 12) acts to decrease the K _e cos Δθ component.

Therefore, in this embodiment, the denominator component V of the phase error estimation calculation section is the frequency estimated 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 coefficient setting value K _e ^* , the d-axis inductance setting value L _d ^* , and the estimated q-axis inductance value L _q ^** The estimated value L _q ^** of the q-axis inductance is calculated from (Equation 10) as follows.

In other words, by calculating the estimated value L _q ^** of the q-axis inductance so that the denominator component V in the calculation formula for the phase error estimate Δθ _c follows the ideal predetermined value V ^* of (Equation 8), the denominator component It controls V.

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

FIG. 5 shows the control characteristics in this example. The same load torque as in Fig. 4 is applied from point A. At point c, the q-axis inductance estimation calculation unit starts estimating the q-axis inductance _Lq , and calculates _Lq ^** / _Lq , which is the ratio between the estimated q-axis inductance value _Lq ^** and the actual q-axis inductance _Lq . is almost 1.0 at point D.

In order to estimate the q-axis inductance L _q with high precision (L _q ^** ≒ L _q ), this implementation is possible without causing vibrations in the d-axis current i _d and q-axis current i _q or out-of-step of the permanent magnet motor. It can be seen that the effect of the example is obvious.

In the above embodiment, the proportional control Kp _Lq and the integral control gain Ki _Lq are set to fixed values in the q- ^axis inductance estimation calculation unit 8, but as shown in _FIG . It may be changed depending on the current detection value i _dc .

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

In the PI control unit 81b, the gain of the proportional control and integral control is changed approximately in proportion to the magnitude of the estimated frequency value ω _r ^{^} and the detected current value i _dc on the d-axis. The denominator component V changes to its predetermined value V ^* according to the frequency and current value. Highly accurate estimation of the q-axis inductance _Lq can be achieved in a shorter time.

Here, a verification method when this embodiment is adopted will be described using FIG. 7. A voltage detector 22 and a current detector 23 are attached to a 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 includes pseudo three-phase AC voltage detection values (v _uc , v _vc , v _wc ), which are the outputs of the voltage detector 22 and the current detector 23 , and three-phase AC current. The detected values (i _uc , i _vc , i _wc ) and the position θ, which is the output of the encoder, are input, and the vector voltage components v _dcc , v _qcc , the vector current components i _dcc , i _qcc , and the position θ are differentiated. Calculate the detected value ω _r . The waveform observation unit 26 calculates the estimated value Δθ _cc of the phase error using equation (13).

Even if the magnitude of the q-axis inductance L _q ^* set in the power converter 21 is changed, as long as the denominator component shown in (Equation 13) remains constant, it is clear that this embodiment is adopted.

According to the first embodiment, it is possible to realize a power conversion device that can estimate the q-axis inductance with high accuracy. Furthermore, since it is possible to estimate the q-axis inductance with high precision, stable and highly efficient motor operation can be achieved.

FIG. 8 is a diagram showing the configuration of a power conversion device and a permanent magnet motor 1 according to the second embodiment. In Example 1, the q-axis inductance was estimated during actual operation, and the estimated value of the q-axis inductance was used in 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 detected q-axis current value i _qc and the estimated q-axis inductance value L _q ^** , and uses it from the next startup. Set the estimated q-axis inductance value 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, speed control calculation unit 9, vector control calculation unit 10, coordinate conversion unit 11, and 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 includes 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 ^** . The selection switch SW13 selects the output of the q-axis inductance estimation calculating section 8 when the input value is "0", the output of the q-axis inductance table reference section 12 when the input value is "1", and selects the q-axis inductance estimated value L _q Output as ^** .

The selection switch SW13 determines the relationship between the q-axis current detection value i _qc and the q-axis inductance estimated value L _q ^** during actual operation every time the q-axis inductance estimation calculation unit 8 is executed when the input value is "0". Created and saved as a corresponding table.

From the next startup, the input value of the selection switch SW13 is set from "0" to "1", and the q-axis inductance table reference section 12 reads the q-axis current detection 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 estimated q-axis inductance value L _q ^** changes according to the q-axis current value, so that highly efficient operation can be quickly realized.

Alternatively, once the estimated q-axis inductance value in all operating ranges is known, set the input value of the selection switch SW13 from "0" to "1" and obtain the estimated q-axis inductance value L _q ^** from the created table. However, it may also be set in the internal memory of a microcomputer installed in the power converter.

According to the second embodiment, by obtaining the q-axis inductance estimate from the above-described correspondence table, a highly accurate q-axis inductance estimate can be obtained even if the q-axis inductance is not estimated during actual operation. Furthermore, since it is possible to estimate the q-axis inductance with high precision, stable and highly efficient motor operation can be achieved.

FIG. 9 shows a configuration diagram of a power conversion device and a synchronous reluctance motor 1a according to the third embodiment. In the first and second embodiments, the examples relate to a power converter that drives a permanent magnet motor, but this embodiment relates to a power converter that drives a synchronous reluctance motor 1a.

In FIG. 9, the components are a power converter 2, a current detector 3, a coordinate transformation 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, and a speed The control calculation section 9, vector control calculation section 10, coordinate conversion section 11, and DC power supply 20 are the same as those in FIG. The control unit is the same as in the second embodiment.

A permanent magnet motor has a permanent magnet embedded in its rotor, but the synchronous reluctance motor 1a does not have a permanent magnet, and a current magnetic flux due to saliency is obtained by a cavity (flux barrier) provided in the rotor.

When the estimated value Δθ _c of the phase error is calculated using the equation (5), the denominator component includes voltage information due to saliency. Therefore, if the predetermined value calculation section calculates the predetermined voltage value V ^** using (Equation 14), control equivalent to that of a permanent magnet motor can be realized.

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

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

Embodiment 4 is an application of Embodiment 2 to a drive system for a permanent magnet motor. In FIG. 10, the components are a permanent magnet motor 1, 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, The vector control calculation unit 10, coordinate conversion unit 11, q-axis inductance table reference unit 12, and selection switch SW13 are the same as those in FIG. The control unit is the same as in the second embodiment.

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

Furthermore, the power converter 2, current detector 3, DC power supply 20, and CPU (not shown) constituting a control unit are implemented as hardware. The CPU executes the above program.

The control unit of the power conversion device calculates the estimated q-axis inductance value by the q-axis inductance estimation calculation unit 8, or calculates the estimated q-axis inductance value from a relational table that records the detected q-axis current value and the estimated q-axis inductance value. It has a selection switch SW13 for selecting whether to acquire the . 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.

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

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

Further, the input value to the selection switch SW13 may be set on a programmable logic controller, a local area network connected to a computer, or a field bus of a 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 , the q-axis current detection value i Create a d-axis voltage correction value Δv _dc and a q-axis voltage correction value Δv _qc from _qc , and add these voltage correction values to vector control voltage reference values v _dc ^* and v _qc ^* (shown in equation 4). performed the calculation.

Other calculation methods include vector control calculation 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 . Create intermediate d-axis current command value i _d ^** and q-axis current command value i _q ^** shown in (Equation 15) to be used, and calculate estimated frequency value ω _r ^ and electric circuit of permanent magnet motor 1. The vector control calculation shown in (Equation 16) is performed using constants to calculate the second voltage command value v _dc ^*** of the d-axis and the second voltage command value v _qc ^*** of the q-axis. It's okay.

Here, K _pd1 is the proportional gain of d-axis current control, K _id1 is the integral gain of d-axis current control, K _pq1 is the proportional gain of q-axis current control, and K _iq1 is the integral gain of 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 current command value i d * used for vector control calculation can be calculated. Voltage correction value Δv _{d_p} ^* of proportional calculation component, voltage correction value Δv _{d_i} ^* of d-axis integral calculation component, voltage correction value Δv _{q_p} ^* of q-axis proportional calculation component, voltage correction value Δv of q-axis integral calculation component _{q_i} ^* is created using (Equation 17). Then, the vector control calculation shown in (Equation 18) using the estimated frequency value ω _r ^{^} and the electric circuit constant of the permanent magnet motor 1 is performed, and the third voltage command value v _dc ^**** of the d axis and the q axis 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. It is.

In addition, using the d-axis current command value i _d ^* , the first-order lag signal i _qctd of the q-axis current detection value i _qc , the frequency command value ω _r ^* , and the electric circuit constant of the permanent magnet motor 1, it is expressed as (Equation 19). Vector control calculation may be performed to calculate the fourth voltage command value v _dc ^***** of the d-axis and the fourth voltage command value v _qc ^***** of 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 obtained by passing i _qc through a first-order lag filter.

In addition, in the first to third embodiments 1 to 3, the switching elements constituting the power converter 2 may be Si (silicon) semiconductor elements, SiC (silicon carbide), GaN (gallium), etc. It may also be a wide bandgap semiconductor element such as nitride.

DESCRIPTION OF SYMBOLS 1... Permanent magnet motor, 1a... Synchronous reluctance motor, 2... Power converter, 3... Current detector, 4... Coordinate conversion section, 5... Phase error estimation calculation section, 6... Frequency estimation calculation section, 7... Phase estimation calculation Part, 8... Q-axis inductance estimation calculation unit, 9... Speed control calculation unit, 10... Vector control calculation unit,
DESCRIPTION OF SYMBOLS 11... Coordinate conversion part, 12... Q-axis inductance table reference part, 13... Switch, 20... DC power supply, 21... Power conversion device

Claims (12)

a power converter having a switching element;
a control unit that controls the power converter that drives the motor;
The control unit includes:
Calculating an estimated phase error value that is a deviation between a rotational phase value of the motor and an estimated rotational phase value;
A power conversion device that calculates a q-axis inductance estimate so that a component inversely proportional to the phase error estimate follows a predetermined value. The power conversion device according to claim 1,
The control unit includes:
A power conversion device including a phase estimation calculation section that calculates the rotational phase estimation value from the frequency estimation value. The power conversion device according to claim 1,
The control unit includes:
A power conversion device including a vector control calculation unit that controls the frequency and voltage of the power converter. The power conversion device according to claim 1,
The control unit includes:
A power conversion device including a frequency estimation calculation unit that controls a frequency estimation value so as to make a phase error zero. The power conversion device according to claim 1,
The control unit includes:
a q-axis inductance estimation calculation unit that calculates the predetermined value from the estimated frequency value, the detected d-axis current value, the induced voltage coefficient of the motor, the d-axis inductance, and the estimated q-axis inductance value; Power converter. 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. The power conversion device according to claim 1,
The control unit includes:
The phase is determined from the d-axis voltage command value, the q-axis voltage command value, the q-axis inductance estimated value, the frequency estimate, the d-axis current detection value, the q-axis current detection value, and the electric circuit constant of the motor. A power conversion device including a phase error estimation calculation unit that calculates an error estimation value. The power conversion device according to claim 1,
A power converter device in which the component inversely proportional to the phase error estimation value is a denominator component of an arithmetic expression for phase error estimation. The power conversion device according to claim 5,
The q-axis inductance estimation calculation unit is
A power conversion device that changes gains of proportional control and integral control according to the estimated frequency value or the detected d-axis current value. The power conversion device according to claim 1,
The control unit includes:
Create a relationship table between the q-axis current detection value and the q-axis inductance estimated value,
A power conversion device including a q-axis inductance table reference unit that obtains the q-axis inductance estimated value from the q-axis current detection value and the relationship table. The power conversion device according to claim 1,
The control unit includes:
After creating a relationship table between the q-axis current detection value and the q-axis inductance estimated value,
A power conversion device that obtains the q-axis inductance estimate from the relationship table without calculating the q-axis inductance estimate. The power conversion device according to claim 1,
The control unit includes:
Calculating the estimated q-axis inductance value,
a switch for selecting whether to obtain the q-axis inductance estimate from a relationship table between the q-axis current detection value and the q-axis inductance estimate;
The input value for switching the switch is set in memory,
A power conversion device that connects a digital operator, personal computer, tablet, or smartphone device to set or change the input value.

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