WO2024013900A1

WO2024013900A1 - Control device and drive control method

Info

Publication number: WO2024013900A1
Application number: PCT/JP2022/027610
Authority: WO
Inventors: 俊毅鈴木; 碧土山本
Original assignee: 三菱電機株式会社
Priority date: 2022-07-13
Filing date: 2022-07-13
Publication date: 2024-01-18

Abstract

A control device (100) carries out drive control of a multi-phase rotating machine (1). The control device (100) is characterized by comprising: a current detector (2) which is a current detection unit that detects a rotating machine current flowing in the rotating machine (1); a controller (5) which is a drive voltage instruction computing unit that generates, on the basis of the rotating machine current and an estimated value of the rotor position of the rotating machine (1), a drive voltage instruction for driving the rotating machine (1); a voltage applicator (3) which applies a voltage to the rotating machine (1) on the basis of the generated drive voltage instruction; and a position estimator (4) which is a position estimation unit that estimates the rotor position on the basis of the rotating machine current, wherein the position estimator (4) determines, on the basis of a gate signal of the voltage applicator (3), the type of voltage vector output by the voltage applicator (3), computes the rotating machine current change amount per determined type of voltage vector, generates, on the basis of the rotating machine current change amount which is the computation result, an alternating current signal that has a direct current component of zero and that varies at twice the angle of the rotor position, and estimates the rotor position on the basis of the alternating current signal.

Description

Control device and drive control method

The present disclosure relates to a control device and a drive control method for controlling the drive of a rotating machine.

To drive a rotating machine, rotor position information is required. Although the rotor position can be detected using a position sensor, the use of a position sensor causes problems such as increased system size, increased cost, and reduced environmental resistance.

On the other hand, Patent Document 1 discloses a method of estimating the rotor position without using a position sensor. In the method disclosed in Patent Document 1, the rotor position is estimated by utilizing the fact that the amount of change in the rotating machine current during application of an effective voltage vector changes at an angle twice the rotor position.

Japanese Patent Application Publication No. 2018-153027

However, according to the above-mentioned conventional technology, there is a problem in that the position estimation error may increase in the appearance pattern of the effective voltage vector in which the differential information of the rotating machine current becomes a fragmentary signal. For example, when performing current vector control using a three-phase common triangular wave carrier PWM (Pulse Width Modulation), there is a correlation between the type of effective voltage vector that appears due to current vector control and the rotor position. When the machine is driven at low speeds, a certain type of effective voltage vector appears for a long time. When the amount of change in the rotating machine current with respect to the effective voltage vector is obtained under such conditions, the amount of change in the rotating machine current becomes a fragmentary signal.

The present disclosure has been made in view of the above, and provides a control device that is capable of estimating the rotor position with high accuracy even under conditions where the amount of change in the rotating machine current with respect to the effective voltage vector is fragmentary. The purpose is to obtain.

In order to solve the above-mentioned problems and achieve the purpose, a control device of the present disclosure is a control device that performs drive control of a multi-phase rotating machine, and includes a current detection unit that detects a rotating machine current flowing through the rotating machine. a drive voltage command calculation unit that generates a drive voltage command for driving the rotating machine based on the rotating machine current and an estimated value of the rotor position of the rotating machine; a voltage applier that applies a voltage to the rotor; and a position estimator that estimates the rotor position based on the rotating machine current; The type of vector is determined, the amount of change in the rotating machine current is calculated for each type of voltage vector determined, and based on the amount of change in the rotating machine current that is the calculation result, the DC component is zero and the angle is twice the rotor position. The present invention is characterized in that an alternating current signal is generated that changes in the alternating current signal, and the rotor position is estimated based on the alternating current signal.

According to the present disclosure, it is possible to obtain a control device that can estimate the rotor position with high accuracy even under conditions where the amount of change in the rotating machine current with respect to the effective voltage vector is fragmentary.

A diagram showing the configuration of a control device for a rotating machine according to Embodiment 1. A diagram showing an example of the circuit configuration of the voltage applicator shown in FIG. A diagram showing an example of the correspondence between the switching state of each phase of the voltage applicator shown in FIG. 1 and the definition of the voltage vector. A diagram showing the eight switching states and voltage vectors shown in FIG. Diagram for explaining signal processing in the position estimator shown in FIG. 1 A diagram showing the detailed configuration of the current differential information calculation section shown in FIG. Diagram showing DC and AC components included in current differential information A diagram showing the output of the current differential information calculation section shown in FIG. Diagram to explain the classification performed by the classifier An explanatory diagram of the operation of the classifier shown in Figure 5 A block diagram showing the configuration of the phase synchronization calculation section shown in FIG. A diagram showing the output of each part of the position estimator shown in FIG. A diagram showing a first example of a hardware configuration for realizing the functions of the control device according to Embodiment 1 and Embodiment 2. A diagram showing a second example of a hardware configuration for realizing the functions of the control device according to Embodiment 1 and Embodiment 2.

Below, a control device and a drive control method according to an embodiment of the present disclosure will be described in detail based on the drawings.

Embodiment 1.
FIG. 1 is a diagram showing the configuration of a control device for a rotating machine according to a first embodiment. Hereinafter, the "rotating machine control device" may be simply referred to as the "control device." The control device 100 shown in FIG. 1 includes a rotating machine 1, a current detector 2, a voltage applier 3, a position estimator 4, and a controller 5. The controller 5 includes a current controller 6 , a rotating coordinate inverse converter 7 , a two-phase three-phase converter 8 , a three-phase two-phase converter 9 , and a rotating coordinate converter 10 .

The rotating machine 1 is a three-phase synchronous reluctance motor (SynRM) that generates torque by utilizing the saliency of the rotor. A voltage applicator 3 is connected to the rotating machine 1, and a current detector 2 is provided between the rotating machine 1 and the voltage applicator 3.

The current detector 2 detects the alternating current supplied from the voltage applicator 3 to the rotating machine 1 and outputs the alternating current as rotating machine currents i _u , _iv , i _w . The rotating machine currents i _u , i _v , i _w are supplied to the rotating machine 1 and are also output to each of the position estimator 4 and controller 5 .

The voltage applicator 3 supplies AC power to the rotating machine 1 according to rotating machine voltage commands v _u *, v _v *, v _w * supplied from the controller 5 .

The position estimator 4 calculates the estimated rotor position using the rotating machine currents i _u , i _v , i _w detected by the current detector 2 and a gate signal from the voltage applicator 3, which will be described later. In the following description, the rotor position will be expressed as "θ", and the estimated value of the rotor position θ will be expressed by adding "^" above "θ". Note that a symbol with "^" added above "θ" may also be expressed by adding "^" after "θ". Similarly, a symbol with "^" added above or after a symbol representing a certain parameter represents the estimated value of that parameter. The position estimator 4 outputs the estimated rotor position θ^ to the controller 5.

The controller 5 controls the rotating machine 1 so that the rotating machine currents i _d , i _q on the rotating coordinates of the rotating machine 1 become values indicated by the rotating machine current commands i _d *, i _q * on the rotating coordinates. The rotating machine voltage commands v _u *, v _v *, v _w * that drive the rotating machine voltage commands v _u *, v v *, v w * are calculated, and the calculated rotating machine voltage commands v u *, v _v *, v _w * are output to the voltage applicator 3.

FIG. 2 is a diagram showing an example of the circuit configuration of the voltage applicator 3 shown in FIG. 1. FIG. 2 shows an example of a circuit configuration when the voltage applicator 3 is a three-phase PWM inverter. The voltage applicator 3 includes a leg 30A in which a semiconductor element UP in the upper arm and a semiconductor element UN in the lower arm are connected in series, and a semiconductor element VP in the upper arm and a semiconductor element VN in the lower arm are connected in series. It has a leg 30B and a leg 30C in which an upper arm semiconductor element WP and a lower arm semiconductor element WN are connected in series. Leg 30A, leg 30B, and leg 30C are connected in parallel to each other.

A bus voltage is applied to the voltage applicator 3 through the

DC buses

35a and 35b. The voltage applicator 3 converts the DC power of the power source 36 supplied through the

DC buses

35a and 35b into AC power, and drives the rotating machine 1 by supplying the converted AC power to the rotating machine 1. Note that the current detector 2 is omitted in FIG. 2.

FIG. 2 illustrates a case where the semiconductor elements UP, UN, VP, VN, WP, and WN are metal-oxide-semiconductor field-effect transistors (MOSFETs). Each of the semiconductor elements UP, UN, VP, VN, WP, and WN includes a transistor 30a and a diode 30b connected antiparallel to the transistor 30a. "Connected in antiparallel" means that the anode side of the diode is connected to the first terminal corresponding to the source of the MOSFET, and the cathode side of the diode is connected to the second terminal corresponding to the drain of the MOSFET.

Note that for the semiconductor elements UP, UN, VP, VN, WP, and WN, for example, insulated gate bipolar transistors (IGBT) may be used instead of MOSFETs.

A connection point 32 between the semiconductor element UP of the upper arm and the semiconductor element UN of the lower arm is connected to the first phase of the rotating machine 1, for example, the u phase. A connection point 33 between the semiconductor element VP of the upper arm and the semiconductor element VN of the lower arm is connected to the second phase of the rotating machine 1, for example, the v phase. A connection point 34 between the semiconductor element WP of the upper arm and the semiconductor element WN of the lower arm is connected to the third phase of the rotating machine 1, for example, the w phase. In the voltage applicator 3, the

connection points

32, 33, and 34 constitute AC terminals.

Here, the voltage vector output by the voltage applicator 3 will be explained. The voltage applicator 3 is a three-phase PWM inverter as described above, and is a power converter that obtains a desired voltage by PWM-controlling the power source 36 supplied through the

DC buses

35a and 35b. A three-phase PWM inverter has two switching elements, upper and lower, for each phase, and the upper and lower switching elements operate so that one of them is in an on state. Therefore, in the three-phase triangular wave comparison inverter, there are 2 cubed types, that is, eight types of switching states. Here, the states of the upper arm gate signals of the u-phase, v-phase, and w-phase in the voltage applicator 3 are defined as _Gu , _Gv , and _Gw, respectively. When the value of G _u , G _v , G _w is 1, it means that the semiconductor element of the upper arm of the corresponding phase is in a conductive state, and when the value of G _u , G _v , G _w is 0, the corresponding This means that the semiconductor element in the lower arm of the phase is in a conductive state. For example, under the condition (G _u , G _v , G _w ) = (1, 0, 0), the semiconductor element in the upper arm of the u phase is conductive, and the semiconductor element in the lower arm of the v phase and w phase is conductive. means the state of being

Here, voltage vectors in each of the eight switching states of the voltage applicator 3 are defined as V ₀ to V ₇ . FIG. 3 is a diagram showing an example of the correspondence between the switching state of each phase of the voltage applicator 3 shown in FIG. 1 and the definition of a voltage vector. Under the condition of (G _u , G _v , G _w ) = (0, 0, 0), the applied voltage vector is defined as V ₀ , and (G _u , G _v , G _w ) = (1, 0, 0), the applied voltage vector is defined as V ₁ , and under the conditions (G _u , G _v , G _w ) = (1, 1, 0), the applied voltage vector is defined as V ₂ The applied voltage vector is defined as V ₃ under the condition that (G _u , G _v , G _w )=(0, 1, 0). Also, under the conditions of (G _u , G _v , G _w )=(0, 1, 1), the applied voltage vector is defined as V ₄ , and (G _u , G _v , G _w )=(0, 0, 1), the applied voltage vector is defined as V ₅ , and under the condition (G _u , G _v , G _w ) = (1, 0, 1), the applied voltage vector is defined as V ₆ The applied voltage vector is defined as V ₇ under the condition of (G _u , G _v , G _w )=(1, 1, 1). Among these eight voltage vectors V ₀ to V ₇ , voltage vectors V ₀ and V ₇ are referred to as zero voltage vectors, and the others, that is, voltage vectors V ₁ to V ₆ are referred to as effective voltage vectors. Note that the voltage vectors V ₀ to V ₇ may be expressed as voltage vectors V _{0 to 7} . Similarly, the effective voltage vectors V ₁ to V ₆ may be expressed as effective voltage vectors V _{1 to V 6} .

FIG. 4 is a diagram showing the eight switching states and voltage vectors shown in FIG. 3. FIG. 4 shows the voltage vector in each switching state and the conduction state of each semiconductor element of the voltage applicator 3.

FIG. 5 is a diagram for explaining signal processing in the position estimator 4 shown in FIG. 1. The position estimator 4 uses the rotating machine currents i _u , i _v , i _w detected by the current detector 2 and the gate signals G _u , G _v , G _w of the voltage applicator 3 to detect the rotating machine 1 . The estimated rotor position θ^, which is the estimated value of the rotor position, is calculated. Specifically, the position estimator 4 includes a current differential information calculation section 40, a classifier 41, a DC component remover 42, a three-phase two-phase converter 43, and a phase synchronization calculation section 44.

The current differential information calculating section 40 calculates current differential information corresponding to each of the effective voltage vectors V ₁ to V ₆ . The current differential information calculation unit 40 calculates current differential information corresponding to each of the effective voltage vectors V ₁ to _V ₆ for each of the u-phase, v-phase, and w-phase rotating machine currents i _u , i v , _i w . do. Therefore, the current differential information outputted by the current differential information calculation section 40 is 3×6=18 types. The current differential information is also called the amount of change in rotating machine current. The gate signals G _u , G _v , G _w of the semiconductor elements of the upper arm of each phase of the voltage applicator 3 and the rotating machine currents i _u , i _v , i _w are input to the current differential information calculation unit 40 . Ru.

FIG. 6 is a diagram showing a detailed configuration of the current differential information calculation section 40 shown in FIG. 5. As shown in FIG. The current differential information calculation unit 40 includes a voltage vector determiner 400 that determines the type of voltage vector output by the voltage applicator 3, and a determination result of the voltage vector determiner 400 and rotating machine currents i _u , i _v , i _w . It has a current differential calculator 401 that calculates current differential information of each phase corresponding to the effective voltage vector using .

_Based _on the definition _shown in FIG. Determine the type of vector. The voltage vector determiner 400 determines which of the voltage vectors V _{0 to V 7} the type of voltage vector is from the values of the gate signals G _u , G _v , and G _w , and determines the voltage vector V ₀ as the determination result. _~7 is output to the current differential calculator 401.

The current differential calculator 401 calculates each of the effective voltage vectors V 1 _{to 6} based on the voltage vectors V _{0 to 7} , which are the determination results of the voltage vector determiner 400, and the rotating machine currents i _u , i _v , and i _w . Calculate current differential information for each phase corresponding to . The current differential calculator 401 stores the types of the current voltage vectors V _{0 to V 7} and the type of the voltage vector one control period ago, and when the same effective voltage vector appears for two or more control periods, the effective Calculate current differential information for each phase corresponding to the type of voltage vector. The control period is set to a value sufficiently short with respect to the period of the triangular wave carrier of the voltage applicator 3 in order to sample the current at two or more points while applying the effective voltage vector. If the current voltage vector type is V _N and the voltage vector type one control period ago is V _N , the current differential calculator 401 calculates the u-phase, v-phase, and w-phase when V _N is applied. The current differential information of is calculated as "di _uVN /dt", "di _vVN /dt", and "di _wVN /dt", respectively. N is an integer from 1 to 6. The current differential calculator 401 calculates 18 types of current differential information "di _uV1 _{to 6} /dt", "di _divV1-6 /dt" and "di _wV1-6 /dt" are output.

Here, a total of 18 types of current differential information output by the current differential calculator 401 will be explained. The current differential information includes a DC component and an AC component. FIG. 7 is a diagram showing a DC component and an AC component included in current differential information. In FIG. 7, for each of the 18 types of current differential information, a signal name, a formula representing a DC component, and a formula representing an AC component are associated with each other. In the "signal name", u, v, w indicate the corresponding phase of the rotating machine 1, and V ₁ to V ₆ indicate the type of the corresponding effective voltage vector.

The characteristics of the "DC component" of the current differential information shown in FIG. 7 will be explained. Here, when A is defined by the following formula (1), the "DC component" of the current differential information is generated in the phase in the direction of the effective voltage vector with a magnitude of "2/A", and It occurs with a magnitude of "1/A" with an opposite sign in a phase other than the phase in the direction. Therefore, the sum of the u-phase DC component, the v-phase DC component, and the w-phase DC component while applying the same effective voltage vector becomes zero. Here, V _dc is the DC voltage of the power source 36 of the voltage applicator 3.

L ₀ in the formula (1) is expressed by the following formula (2). Further, L ₁ in the formula (1) is expressed by the following formula (3). Here, L _d is the d-axis inductance of the rotating machine 1, and L _q is the q-axis inductance of the rotating machine 1.

Next, the characteristics of the "AC component" of the current differential information will be explained. Here, if the number of the effective voltage vector is N, the AC component of the current differential information of the u phase is expressed by equation (4), the AC component of the current differential information of the v phase is expressed by equation (5), and w The alternating current component of the phase current differential information is expressed by equation (6).

As shown in equations (4) to (6), the current differential information obtained by applying the effective voltage vector has information on the rotor position θ. The "AC component" column in FIG. 7 shows the expansion of the phases in equations (4) to (6). As is clear from FIG. 7 and equations (4) to (6), the AC components of the current differential information during the application period of the same effective voltage vector have a phase difference of "±2π/3", and It has the characteristic that the phase of each reference shifts depending on the direction of application of the effective voltage vector. The magnitude of the amplitude of the AC component is equal for all combinations of effective voltage vectors and phases, and is "(1/A)×(L ₁ /L ₀ )". In addition, since the magnitude relationship of the d-axis and q-axis inductances is different between an interior permanent magnet synchronous motor (IPMSM) and a synchronous reluctance motor, the cosine function coefficient "(1/A) x (L ₁ /L ₀ )" is a positive value for an embedded magnet type synchronous motor, and a negative value for a synchronous reluctance motor.

In each phase, the current differential information obtained from combinations of effective voltage vectors in the magnetization and demagnetization directions are in a relationship with opposite signs, as expressed by the following equations (7) to (9). be. In formulas (7) to (9), n is an integer from 1 to 3. The combinations of voltage vectors in the magnetization and demagnetization directions are V1 and V4 for the u phase, V3 and V6 for the v phase, and V5 and V2 for the w phase.

FIG. 8 is a diagram showing the output of the current differential information calculation section 40 shown in FIG. 5. Figure 8 shows the simulation results when current vector control is performed on a synchronous reluctance motor rotating at low speed. I am using it. For the sake of explanation, the voltage vector numbers are set to 0 for V0 and V7. Here, when focusing on the rotor position and the number of the applied voltage vector, a correlation can be confirmed between the rotor position and the appearance pattern of the voltage vector. During the period in which a specific effective voltage vector appears, current differential information corresponding to other effective voltage vectors cannot be obtained. In the appearance pattern, current differential information becomes fragmentary. Furthermore, each current differential information has a characteristic that the timing at which it can be acquired differs, and the amount of delay varies depending on the signal. Due to this characteristic, if signal processing is performed without considering the appearance pattern of voltage vectors, position sensorless control will become unstable. Here, "performing signal processing without considering the appearance pattern of voltage vectors" means, for example, when the type of current differential information used to estimate the rotor position is fixed, regardless of the type of voltage vector that appears. is applicable.

Therefore, the position estimator 4 performs signal processing to generate an AC component of continuous current differential information having rotor position information from the fragmentary current differential information. The signal processing method performed by the position estimator 4 will be described below. The current differential information has the characteristics shown in the above equations (4) to (9). By utilizing this feature, the same waveform shape appears in current differential information under different voltage vector and phase conditions. Therefore, the position estimator 4 uses waveform shapes that appear under different voltage vector and phase conditions to interpolate fragmentary current differential information to generate continuous AC components of current differential information.

Returning to the explanation of FIG. 5. The classifier 41 classifies the current differential information output by the current differential information calculation unit 40 into one of six types of signals based on the magnitude of the DC component and the reference phase. The classifier 41 classifies groups (2/A, 0°), group (-1/A, 120°), group (-1/A, -120°), group (2/A, -120°), group (-1/A, 0°), group (2/A, 120°). Classify into.

FIG. 9 is a diagram for explaining the classification performed by the classifier 41. FIG. 9 shows the "group", "DC component", "AC component", and "symbol" of each of the six groups classified by the classifier 41. Here, "group" indicates the name of a group, and a group written as group (X, Y°) means a group in which the DC component is X and the reference phase of the AC component is Y°. For example, the reference phase Y in the cosine component "cos (2θ+2π/3)" of the AC component in FIG. 9 is 2π/3 [rad] = 120 [°]. "Symbols" indicate signals having the same waveform shape. For example, in the group group (2/A, 0°), the waveform of the u-phase current differential information when the effective voltage vector V1 is applied, and the waveform of the u-phase current differential information when the effective voltage vector V4 is applied. This means that the waveform of the current differential information is the same.

FIG. 10 is an explanatory diagram of the operation of the classifier 41 shown in FIG. 5. When the current differential information "di _uV1~6 /dt", " _divV1~6 /dt", and "di _wV1~6 /dt" are input, the classifier 41 classifies six types based on the classification shown in FIG. Generate a signal. Specifically, the classifier 41 prepares variables corresponding to each of the six types of groups, and substitutes the current differential information into the variable of the group into which the current differential information input to the classifier 41 is classified. , variables in other groups operate to retain their previous values. Here, for the sake of explanation, the names of groups are used as variable names. group (X, Y°) is a variable of a group in which the DC component is X and the reference phase of the AC component is Y°. For example, the classifier 41 assigns "di _uV1 /dt" to group (2/A, 0°) under the condition that V1 is applied, and "-di _uV4 /dt" under the condition that V4 is applied. , and under conditions where effective voltage vectors other than V1 and V4, that is, V2, V3, V5, and V6 are applied, the previous value is held. Similarly, the classifier 41 assigns " _divV1 /dt" to group (-1/A, 120°) under the condition that V1 is applied, and assigns "-divV4 /dt" to group (-1/A, 120°) under the condition that _V4 is applied. dt", "di _uV3 /dt" under the condition that V3 is applied, "-di _uV6 /dt" under the condition that V6 is applied, and under the condition that V2 and V5 are applied. , operates to hold the previous value.

Returning to the explanation of FIG. 5. The DC component remover 42 extracts the DC component from the output of the classifier 41 and generates a continuous AC component by subtracting the DC component from current differential information obtained by applying the latest effective voltage vector. . In Embodiment 1, an example will be described in which a DC component is extracted using a three-phase equilibrium condition. To extract the DC component "1/A" using the three-phase equilibrium condition, the following formulas (10) to (14) are used. In other words, the DC component remover 42 calculates the sum of signals of combinations whose phases are 0°, 120°, and -120° from the output of the classifier 41, and multiplies the DC component by a conversion coefficient to remove the DC component. Calculate. Although five types of formulas (10) to (14) are shown here, the DC component remover 42 combines the latest effective voltage vector and the latest effective voltage vector with a different number from the latest effective voltage vector. Accordingly, the calculation may be performed using at least one appropriate formula.

Specifically, the DC component remover 42 uses the latest effective voltage vector and the latest effective voltage vector with a different number from the latest effective voltage vector from among equations (10) to (14). Use formulas. Here, for example, group (2/A, 0°) is generated based on current differential information when effective voltage vector V1 or V4 is applied, and group (2/A, 120°) is It is generated based on the current differential information when the effective voltage vector V5 or V2 is applied, and group (2/A, -120°) is the current differential information when the effective voltage vector V3 or V6 is applied. It is generated based on. Therefore, formula (10) can be said to be a formula that uses effective voltage vectors V1 or V4, V5 or V2, and V3 or V6. Similarly, formula (11) is a formula that uses effective voltage vectors V2 or V5 and V1 or V3 or V4 or V6. Equation (12) is an equation that uses effective voltage vectors V1 or V4 and V2 or V5. Equation (13) is an equation that uses effective voltage vectors V1 or V4 and V3 or V6. Equation (14) is an equation that uses effective voltage vectors V2 or V5 and V3 or V6.

For example, if the combination of the latest effective voltage vector and the latest effective voltage vector with a different number than the latest effective voltage vector is V1 and V2, the formula using these voltage vectors is expressed as formula (10). You only have to choose at least one from ~(14). The formulas using effective voltage vectors V1 and V2 are formula (11) and formula (12). Therefore, the DC component remover 42 calculates the DC component "1/A" using at least one of Equation (11) and Equation (12). When using multiple formulas, the DC component remover 42 can calculate the DC component "1/A" using the average value of the calculation results of the multiple formulas.

Next, the DC component remover 42 uses the extracted DC component to subtract the DC component from the current differential information obtained by applying the latest effective voltage vector. Calculate the components. The DC component remover 42 can calculate the AC component of the latest current differential information using equations (15) to (17) shown below. The DC component remover 42 selects a formula from among formulas (15) to (17) based on the type of the latest voltage vector.

The DC component remover 42 outputs the calculation results group (0, 0°), group (0, 120°), group (0, -120°) to the three-phase two-phase converter 43. The outputs group (0, 0°), group (0, 120°), and group (0, -120°) of the DC component remover 42 become continuous AC components including rotor position information. Hereinafter, a method of calculating the rotor position using this AC component will be explained. To calculate the rotor position from alternating current components that have a phase difference of ±2π/3 from each other, there is a method of converting these alternating current components into three-phase two-phase conversion, calculating arctangent, and performing phase synchronization on the three-phase two-phase conversion results. There are methods of estimating the rotor position by performing calculations. Here, a method of estimating the rotor position by phase synchronization calculation will be explained as an example.

The three-phase two-phase converter 43 calculates an α-axis AC component α and a β-axis AC component β, which are AC components of two orthogonal axes. The three-phase two-phase converter 43 calculates the α-axis AC component α and the β-axis AC component β using the following formula (18), and phase synchronizes the calculated α-axis AC component α and β-axis AC component β. It is output to the calculation section 44.

The phase synchronization calculation unit 44 estimates the rotor position of the rotating machine 1 based on the α-axis AC component α and the β-axis AC component β output from the three-phase two-phase converter 43. Specifically, the phase synchronization calculation unit 44 estimates the rotor position of the rotating machine 1 by performing a phase synchronization calculation on the α-axis AC component α and the β-axis AC component β.

FIG. 11 is a block diagram showing the configuration of the phase synchronization calculation section 44 shown in FIG. 5. The phase synchronization calculation unit 44 includes a phase error calculation unit 441, a PI (Proportional Integral) controller 442, an integrator 443, and proportional units 444 and 445.

The α-axis AC component α and the β-axis AC component β output from the three-phase two-phase converter 43 and the estimated rotor position 2θ^ output from the integrator 443 are input to the phase error calculation unit 441. The phase error calculation unit 441 calculates the phase error Δi _AC *Δ2θ according to the following equation (19). The phase error calculation unit 441 outputs the calculated phase error Δi _AC *Δ2θ to the PI controller 442.

Here, "Δi _AC " in the formula (19) is expressed by the following formula (20).

The phase error Δi _AC *Δ2θ output from the phase error calculation unit 441 is input to the PI controller 442 . The PI controller 442 outputs the estimated speed 2ω^ so that the phase error Δi _AC *Δ2θ becomes zero.

The integrator 443 integrates the estimated speed 2ω^ output by the PI controller 442, and outputs the integrated value as the estimated rotor position 2θ^. The estimated rotor position 2θ^ output from the integrator 443 is fed back to the phase error calculation unit 441.

In the above formula (19), when “2θ>2θ^”, the phase error Δi _AC *Δ2θ is a positive value, so the estimated speed 2ω^ and the estimated rotor position 2θ^ are corrected in the direction of increase. Ru. Furthermore, when "2θ<2θ^", the phase error Δi _AC *Δ2θ takes a negative value, so the estimated speed 2ω^ and the estimated rotor position 2θ^ are corrected in the direction of decreasing. Finally, "2θ=2θ^" is established, and the phase and frequency of the AC component of the current differential information of the rotating machine 1 are estimated. In this way, the phase lock calculation section 44 takes the form of a phase locked loop (PLL).

The phase synchronization calculation unit 44 calculates the estimated rotor position θ^ by inputting the estimated rotor position 2θ^ into the proportional device 444 and multiplying it by 0.5. Further, the phase synchronization calculating section 44 calculates the estimated speed ω^ by inputting the estimated speed 2ω^ into the proportional device 445 and multiplying it by 0.5.

FIG. 12 is a diagram showing the output of each part of the position estimator 4 shown in FIG. 5. In FIG. 12, the operating conditions are the same as those in FIG. 8, and the current differential information is fragmentary. "Rotor position" in the first row from the top of FIG. 12 shows the true position of the rotor and the estimated position output by the phase synchronization calculation unit 44. The second to fourth rows from the top of FIG. 12 show the output of the current differential information calculation section 40. The fifth row from the top of FIG. 12 shows the output of the classifier 41. The sixth row from the top of FIG. 12 shows the output of the DC component remover 42. The seventh row from the top of FIG. 12 shows the output of the three-phase two-phase converter 43. The eighth row from the top of FIG. 12 shows the numbers of the voltage vectors applied at each time point. Note that in FIG. 12, as in FIG. 8, the voltage vector numbers are 0 for V0 and V7 for the sake of explanation.

From FIG. 12, it can be seen that the classifier 41 generates six types of signals based on the classification shown in FIG. Further, the output of the DC component remover 42 becomes an AC component expressed on two orthogonal axes in which the DC component is zero and vibrates at an angle twice the rotor position. The position estimator 4 estimates the rotor position by performing phase synchronization calculation on the output of the three-phase two-phase converter 43.

Returning to the explanation of FIG. The rotating machine currents i _u , i _v , i _w detected by the current detector 2 are input to the three-phase two-phase converter 9 of the controller 5 . The three-phase two-phase converter 9 converts rotating machine currents i _u , i _v , i _w on three-phase coordinates into rotating machine currents i _α , i _β on stationary two-phase coordinates. The three-phase two-phase converter 9 outputs rotating machine currents i _α and i _β to the rotating coordinate converter 10 .

The rotating machine currents i _α , i _β output from the three-phase two-phase converter 9 and the estimated rotor position θ^ output from the position estimator 4 are input to the rotating coordinate converter 10 . The rotating coordinate converter 10 converts rotating machine currents i _α , i _β on stationary two-phase coordinates into rotating machine currents i _d , i _q on rotating coordinates using the estimated rotor position θ^. The rotating coordinate converter 10 outputs rotating machine currents i _d and i _q to the current controller 6 .

Rotating machine current commands i _d *, i _q * and rotating machine currents i _d , i _q are input to the current controller 6 . The rotating machine current command i _d * is a command of the d-axis drive current that indicates the armature current component in the d-axis direction where the magnetic resistance of the rotor of the rotating machine 1 is the smallest. The rotating machine current command i _q * is a command for the q-axis drive current that indicates an armature current component in a uniaxial direction that is orthogonal to the d-axis. The current controller 6 controls the current so that the rotating machine currents i _d , i _q output by the rotating coordinate converter 10 become the rotating machine current commands i _d *, i _q *, and changes the rotating machine voltage on the rotating coordinates. Compute commands v _d *, v _q *. The current control in the current controller 6 is, for example, PI control. The current controller 6 outputs rotating machine voltage commands v _d *, v _q *, which are the calculation results, to the rotating coordinate inverse converter 7 .

The rotating machine voltage commands v _d *, v _q * and the estimated rotor position θ^ are input to the rotating coordinate inverse converter 7 . The rotating coordinate inverse converter 7 uses the estimated rotor position θ^ to convert the rotating machine voltage commands v _d *, v _q * on the rotating coordinates calculated by the current controller 6 into the rotating machine on the stationary two-phase coordinates. Convert to voltage commands v _α *, v _β *. The rotating coordinate inverse converter 7 outputs rotating machine voltage commands v _α *, v _β * to the two-phase three-phase converter 8 .

Rotating machine voltage commands v _α *, v _β * are input to the two-phase three-phase converter 8 . The two-phase three-phase converter 8 converts the rotating machine voltage commands v _α *, v _β * on the stationary two-phase coordinates into the rotating machine voltage commands v _u *, v on the three-phase coordinates for driving the rotating machine 1. Convert to _v *, v _w *.

As described above, the control device 100 according to the first embodiment is a control device 100 that performs drive control of the multiphase rotating machine 1, and includes a current detection unit that detects the rotating machine current flowing through the rotating machine 1. A controller 5 that is a drive voltage command calculation unit that generates a drive voltage command for driving the rotating machine 1 based on a certain current detector 2 and the rotating machine current and information on the rotor position of the rotating machine 1; A voltage applicator 3 that applies voltage to the rotating machine 1 based on the generated drive voltage command, and a position estimator that is a position estimator that estimates the rotor position based on the rotating machine current detected by the current detector 2. 4. The position estimator 4 determines the type of voltage vector output by the voltage applicator 3 based on the gate signals _Gu , _Gv , _Gw of the voltage applicator 3, and calculates the rotation machine current for each determined type of voltage vector. Calculate the current differential information, which is the amount of change, and generate an AC signal in which the DC component is zero and changes at twice the angle of the rotor position from the calculation result, the amount of change in the rotating machine current, and based on the generated AC signal. Estimate rotor position. With such a configuration, the control device 100 can determine from the fragmented current differential information that the DC component is zero and the rotor position is correct even in the appearance pattern of the effective voltage vector in which the current differential information is fragmentary. By generating a continuous AC signal that vibrates at double angle, the rotor position can be estimated with high accuracy.

The position estimator 4 can estimate the rotor position, for example, by performing phase synchronization calculation on the generated AC signal. Further, the position estimator 4 continuously calculates current differential information based on a combination of a plurality of current differential information including the same waveform shape among a plurality of current differential information obtained under a plurality of conditions in which at least one of a voltage vector and a phase is different. Generates an AC signal with a waveform shape. More specifically, the position estimator 4 utilizes the feature that the two current differential information obtained under the condition that the voltage vectors are in opposite directions and in the same phase have opposite signs. Therefore, it is possible to generate a continuous AC signal by using the value obtained by multiplying one of the two current differential information obtained under the condition that the voltage vector directions are opposite to each other and are in the same phase. can.

The position estimator 4 can generate a continuous AC signal by utilizing the characteristic that the phase of the AC component of the current differential information shifts depending on the direction of the voltage vector.

Further, as shown in the above formulas (10) to (14), the position estimator 4 has a phase difference of plus two-thirds π between the first current differential information and the first current differential information. Calculating the DC component of the current differential information by calculating the sum of the second current differential information and the third current differential information in which the phase difference between the first current differential information and the first current differential information is -2/3π. I can do it.

The position estimator 4 also includes a phase error calculation unit 441 that calculates a phase error based on an AC signal whose DC component is zero and which changes at twice the angle of the rotor position and an estimated position of the rotor position; It has a PI controller 442 which is an estimated speed generating section that outputs an estimated speed based on an error, and an integrator 443 that outputs a value obtained by integrating the estimated speed as an estimated position.

Embodiment 2.
Control device 100 according to the second embodiment has the same configuration as the first embodiment. In the second embodiment, the overall configuration of control device 100 is similar to that shown in FIG. 1, and the configuration of position estimator 4 is similar to that shown in FIG. 5. Therefore, the second embodiment will also be described using the same reference numerals as those in the first embodiment. However, in the second embodiment, the processing content performed by the DC component remover 42 shown in FIG. 5 is different from the first embodiment. Below, parts that are different from Embodiment 1 will be mainly explained.

In the second embodiment, the DC component remover 42 calculates the DC component "1/A" using the following formulas (21) to (23) instead of the above formulas (10) to (14). do.

In formulas (21) to (23), the DC component "1/A" is calculated by taking the difference between signals that have different DC components and the same reference phase of the AC components among the outputs of the classifier 41. . Although three formulas (21) to (23) are shown here, the DC component remover 42 uses the latest effective voltage vector and the latest effective voltage vector with a different number from the latest effective voltage vector. At least one mathematical formula may be used. Here, for example, group (2/A, 0°) is generated based on current differential information when effective voltage vector V1 or V4 is applied, and group (-1/A, 0°) is generated based on current differential information when effective voltage vector V1 or V4 is applied. , is generated based on current differential information when effective voltage vector V2, V3, V5, or V6 is applied. Therefore, it can be said that Equation (21) is an equation that uses the effective voltage vector V1 or V4 and V2 or V3 or V5 or V6. Similarly, formula (22) is a formula using effective voltage vectors V2 or V5 and V1 or V3 or V4 or V6. Equation (23) is an equation that uses effective voltage vectors V3 or V6 and V1 or V2 or V4 or V5.

For example, if the latest effective voltage vector and the nearest effective voltage vectors with different numbers than the latest effective voltage vector are effective voltage vectors V1 and V2, then equation (21) using effective voltage vectors V1 and V2 and Calculation is performed using at least one of formulas (22). Similarly to Embodiment 1, when using multiple formulas, the DC component remover 42 can calculate the DC component "1/A" using the average value of the calculation results of the multiple formulas. . In this way, the second embodiment differs from the first embodiment in the process of extracting the DC component, but the other processes are the same as in the first embodiment. In the second embodiment, as in the first embodiment, the control device 100 determines whether the DC component is zero or In addition, by generating a continuous AC signal that vibrates at twice the angle of the rotor position, the rotor position can be estimated with high accuracy.

Further, formulas (10) to (14) used in the first embodiment require three signals among the outputs of the classifier 41, whereas formula (21) used in the second embodiment In (23), the DC component “1/A” can be calculated using two signals among the outputs of the classifier 41. Therefore, in the second embodiment, it is possible to obtain the effect that the calculation load is reduced more than in the first embodiment. Furthermore, the method using equations (21) to (23) requires the application of two types of voltage vectors, whereas the method using equations (10) to (14) requires the application of two or three types of voltage vectors. Requires the application of a voltage vector. From the viewpoint of position estimation response, the fewer types of voltage vectors used for calculation, the better the response. Therefore, in the second embodiment, the DC component can be extracted with higher response than the method of the first embodiment.

Next, a hardware configuration for realizing each function of the control device 100 according to the first and second embodiments will be described. Each function mentioned here refers to a function that the current detector 2, voltage applicator 3, position estimator 4, and controller 5 have.

FIG. 13 is a diagram showing a first example of a hardware configuration for realizing the functions of the control device 100 according to the first and second embodiments. FIG. 14 is a diagram showing a second example of a hardware configuration for realizing the functions of control device 100 according to the first and second embodiments. In the first example shown in FIG. 13, the control device 100 includes a dedicated processing circuit 1000, a current detector 2, and a voltage applicator 3. Here, the functions of the current detector 2 and the voltage applicator 3 are realized using dedicated hardware, and the functions of the position estimator 4 and the controller 5 are realized by a dedicated processing circuit 1000. Furthermore, in the second example shown in FIG. 14, the control device 100 includes a processor 1001, a storage device 1002, a current detector 2, and a voltage applier 3. Here, the functions of the current detector 2 and voltage applicator 3 are realized using dedicated hardware, and the functions of the position estimator 4 and controller 5 are realized using a processor 1001 and a storage device 1002. be done. Dedicated processing circuit 1000 and processor 1001 are also referred to as control circuits.

The dedicated processing circuit 1000 is a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. The control device 100 may implement each of the above functions using one dedicated processing circuit 1000, or may implement each of the above functions using a plurality of dedicated processing circuits 1000.

The processor 1001 can realize each function of the control device 100 by reading and executing programs stored in the storage device 1002. Note that, in the control device 100, a plurality of processors 1001 and a plurality of storage devices 1002 may cooperate to realize each of the functions described above.

When using the processor 1001 and the storage device 1002, each of the functions described above is realized by software, firmware, or a combination thereof. Software or firmware is written as a program and stored in storage device 1002. Processor 1001 reads and executes a program stored in storage device 1002. It can also be said that these programs cause a computer to execute procedures and methods for executing each function.

The processor 1001 is a CPU, and is also called a processing device, arithmetic device, microprocessor, microcomputer, DSP (Digital Signal Processor), or the like. The storage device 1002 is, for example, a nonvolatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable ROM), or EEPROM (registered trademark) (Electrically EPROM). , magnetic disk, flexible disk, optical disk, compact disk, mini disk, DVD (Digital Versatile Disk), etc.

The configurations shown in the embodiments above are merely examples, and can be combined with other known techniques, or can be combined with other embodiments, within the scope of the gist. It is also possible to omit or change part of the configuration.

For example, in the first and second embodiments described above, the rotating machine 1 is a synchronous reluctance motor, but the type of the rotating machine 1 is not limited to this. The rotating machine 1 may be a saliency motor such as an embedded magnet synchronous motor or a surface permanent magnet synchronous motor (SPMSM).

Furthermore, in the first and second embodiments described above, the controller 5 of the control device 100 controls the d-axis current and the q-axis current, but the controller 5 also controls torque, rotational speed, etc. It is also possible to have a configuration in which:

Further, in the first and second embodiments described above, the configuration in which the current detector 2 detects the phase current of the rotating machine 1 has been described, but the current detector 2 is an example of a current detection section, and the The example is not limited to. The current detection section only needs to be able to detect the phase current, and may be a current sensor built into an inverter (not shown) that constitutes the voltage applicator 3.

1 Rotating machine, 2 Current detector, 3 Voltage applicator, 4 Position estimator, 5 Controller, 6 Current controller, 7 Rotating coordinate inverse converter, 8 Two-phase three-phase converter, 9, 43 Three-phase two-phase Converter, 10 Rotating coordinate converter, 30a Transistor, 30b Diode, 30A, 30B, 30C Leg, 32, 33, 34 Connection point, 35a, 35b DC bus, 36 Power source, 40 Current differential information calculation unit, 41 Classifier , 42 DC component remover, 44 Phase synchronization calculation unit, 100 Control device, 400 Voltage vector determiner, 401 Current differential calculation unit, 441 Phase error calculation unit, 442 PI controller, 443 Integrator, 444, 445 Proportional unit, 1000 Dedicated processing circuit, 1001 Processor, 1002 Storage device, UP, UN, VP, VN, WP, WN semiconductor element.

Claims

A control device that performs drive control of a multiphase rotating machine,
a current detection unit that detects a rotating machine current flowing through the rotating machine;
a drive voltage command calculation unit that generates a drive voltage command for driving the rotating machine based on the rotating machine current and an estimated value of the rotor position of the rotating machine;
a voltage applicator that applies voltage to the rotating machine based on the generated drive voltage command;
a position estimation unit that estimates the rotor position based on the rotating machine current;
Equipped with
The position estimation unit determines a type of voltage vector output by the voltage applicator based on a gate signal of the voltage applicator, and calculates an amount of change in the rotating machine current for each determined type of voltage vector, It is characterized by generating an AC signal in which the DC component is zero and changes at twice the angle of the rotor position based on the rotating machine current change amount which is the calculation result, and estimating the rotor position based on the AC signal. control device.
The control device according to claim 1, wherein the position estimation unit estimates the rotor position by performing phase synchronization calculation on the alternating current signal.
The position estimating unit is based on a combination of a plurality of rotating machine current variations having the same waveform shape, among the plurality of rotating machine current variations obtained under a plurality of conditions in which at least one of a voltage vector and a phase is different. The control device according to claim 1 or 2, wherein the alternating current signal has a continuous waveform.
The position estimating unit calculates the voltage by utilizing the characteristic that the two rotating machine current changes obtained under the same phase condition with the directions of the voltage vectors being opposite to each other and having opposite signs to each other. The alternating current signal is generated using a value obtained by multiplying one of the two rotating machine current changes obtained under the condition that the vector directions are opposite to each other and the same phase is applied. The control device according to claim 3.
According to claim 3 or 4, the position estimation unit generates the alternating current signal by utilizing a characteristic that the phase of the alternating current component of the rotating machine current change is shifted depending on the direction of the voltage vector. Control device as described.
The position estimating unit calculates a DC component of the rotating machine current change amount, and calculates an AC component of the rotating machine current change amount by subtracting the calculated DC component from the rotating machine current change amount. The control device according to any one of claims 3 to 5, wherein the AC signal is generated based on an AC component.
The position estimating unit is configured to detect a second rotation in which a phase difference between a first rotating machine current variation and the first rotating machine current variation among the rotating machine current variations is +2/3π. Calculating the DC component by calculating the sum of the machine current change amount and a third rotating machine current change amount whose phase difference with the first rotating machine current change amount is -2/3π. The control device according to claim 6, characterized in that:
The position estimating unit calculates the DC component by calculating the difference between two rotating machine current changes in which the alternating current component has the same phase and the DC component has different magnitudes. The control device according to claim 6, wherein the control device performs a calculation.
The position estimating unit is
a phase error calculation unit that calculates a phase error based on the AC signal in which the DC component is zero and changes at an angle twice the rotor position and the estimated rotor position;
an estimated speed generation unit that outputs an estimated speed based on the phase error;
an integrator that outputs a value obtained by integrating the estimated speed as the estimated position;
The control device according to any one of claims 1 to 8, characterized in that it has the following.
A drive control method for a multiphase rotating machine, the method comprising:
detecting a rotating machine current flowing through the rotating machine;
generating a drive voltage command for driving the rotating machine based on the rotating machine current and an estimated value of the rotor position of the rotating machine;
applying a voltage to the rotating machine based on the generated drive voltage command;
estimating the rotor position based on the rotating machine current;
Equipped with
In the step of estimating the rotor position, the type of voltage vector output by the voltage applicator is determined based on the gate signal of the voltage applicator that applies voltage to the rotating machine, and for each type of the determined voltage vector, The amount of change in the rotating machine current is calculated, and based on the amount of change in the rotating machine current that is the calculation result, an AC signal in which the DC component is zero and changes at twice the angle of the rotor position is generated, and based on the AC signal, A drive control method characterized by estimating a rotor position using