Control device and drive control method

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

[Technical Field]

[0001] The present disclosure relates to a control device and a drive control method for controlling the drive of a rotating machine. [Background technology]

[0002] Driving a rotating machine requires rotor position information. While the rotor position can be detected using a position sensor, using a position sensor leads to problems such as an increase in system size, higher costs, and reduced environmental resistance.

[0003] In contrast, Patent Document 1 discloses a method for estimating the rotor position without using a position sensor. The method disclosed in Patent Document 1 estimates the rotor position 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 that of the rotor position. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-153027 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-described conventional techniques have a problem in that position estimation errors may increase in the occurrence pattern of effective voltage vectors in which the differential information of the rotating machine current is a fragmented signal. For example, when current vector control is performed using PWM (Pulse Width Modulation) with a three-phase common triangular wave carrier, there is a correlation between the type of effective voltage vector that appears by current vector control and the rotor position. When the rotating machine is driven at low speed, a specific type of effective voltage vector appears for a long period of time. Under such conditions, when the change in the rotating machine current relative to the effective voltage vector is acquired, the change in the rotating machine current becomes a fragmented signal.

[0006] The present disclosure has been made in consideration of the above, and aims to provide a control device that can estimate rotor position with high accuracy even under conditions where the amount of change in rotating machine current relative to the effective voltage vector is fragmented. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, the control device of the present disclosure includes: Has saliency A control device for drive control of a polyphase rotating machine 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 a rotor position of the rotating machine, a voltage applicator that applies a voltage to the rotating machine based on the generated drive voltage command, and a position estimation unit that estimates the rotor position based on the rotating machine current, wherein the position estimation unit determines the type of voltage vector output by the voltage applicator based on a gate signal of the voltage applicator, calculates an amount of change in the rotating machine current for each determined type of voltage vector, generates an AC signal with zero DC component and that changes at twice the angle of the rotor position based on the amount of change in the rotating machine current that is the calculation result, and estimates the rotor position based on the AC signal. [Effects of the Invention]

[0008] 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 in which the amount of change in the rotating machine current relative to the effective voltage vector is fragmented. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing a configuration of a control device for a rotating machine according to a first embodiment; [Figure 2] FIG. 2 is a diagram showing an example of a circuit configuration of the voltage applicator shown in FIG. 1; [Figure 3] FIG. 2 is 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 a voltage vector. [Figure 4]A diagram showing the eight switching states and voltage vectors shown in Figure 3. [Figure 5] FIG. 2 is a diagram illustrating signal processing in the position estimator shown in FIG. 1; [Figure 6] FIG. 6 is a diagram showing a detailed configuration of the current differential information calculation unit shown in FIG. 5. [Figure 7] FIG. 1 is a diagram showing DC and AC components included in current differential information; [Figure 8] FIG. 6 is a diagram showing the output of the current differential information calculation unit shown in FIG. 5. [Figure 9] A diagram to explain the classification performed by the classifier [Figure 10] An explanation of the operation of the classifier shown in Figure 5. [Figure 11] A block diagram showing the configuration of the phase synchronization calculation unit shown in Figure 5. [Figure 12] FIG. 6 shows the output of each part of the position estimator shown in FIG. 5. [Figure 13] FIG. 1 is a diagram illustrating a first example of a hardware configuration for realizing the functions of the control device according to the first and second embodiments. [Figure 14] FIG. 10 is a diagram illustrating a second example of a hardware configuration for realizing the functions of the control device according to the first and second embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a control device and a drive control method according to an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

[0011] Embodiment 1 FIG. 1 is a diagram illustrating a configuration of a rotating machine control device according to a first embodiment. Hereinafter, the "rotating machine control device" may be simply referred to as the "control device." The control device 100 illustrated in FIG. 1 includes a rotating machine 1, a current detector 2, a voltage applicator 3, a position estimator 4, and a controller 5. The controller 5 includes a current controller 6, a rotating coordinate inverter 7, a two-phase to three-phase converter 8, a three-phase to two-phase converter 9, and a rotating coordinate converter 10.

[0012] The rotating machine 1 is a three-phase synchronous reluctance motor (SynRM) that generates torque by utilizing the saliency of its 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.

[0013] The current detector 2 detects the AC current supplied from the voltage applicator 3 to the rotating machine 1 and converts the AC current into a rotating machine current i u ,i v ,i w The rotating machine current i u ,i v ,i w is supplied to the rotating machine 1 and is also output to the position estimator 4 and the controller 5.

[0014] The voltage applicator 3 applies the rotating machine voltage command v supplied from the controller 5. u *,v v *,v w AC power is supplied to the rotating machine 1 according to *.

[0015] The position estimator 4 estimates the rotating machine current i detected by the current detector 2. u ,i v ,i w and a gate signal from the voltage applicator 3, which will be described later, to calculate an estimated rotor position. In the following description, the rotor position is represented as "θ", and the estimated value of the rotor position θ is represented by adding "^" above "θ". Note that a symbol with "^" above "θ" can also be represented by adding "^" after "θ". Similarly, a symbol with "^" above or after a symbol representing a parameter represents an estimated value of that parameter. The position estimator 4 outputs the estimated rotor position θ^ to the controller 5.

[0016] The controller 5 calculates the rotating machine current i on the rotating coordinate system of the rotating machine 1. d ,i q is the rotating machine current command i on the rotating coordinate system d *,i q The voltage command v that drives the rotating machine 1 is set to the value indicated by *. u *,vv *,v w * is calculated, and the calculated rotating machine voltage command v u *,v v *,v w * is output to the voltage applicator 3.

[0017] 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 the circuit configuration when the voltage applicator 3 is a three-phase PWM inverter. The voltage applicator 3 has a leg 30A in which an upper-arm semiconductor element UP and a lower-arm semiconductor element UN are connected in series, a leg 30B in which an upper-arm semiconductor element VP and a lower-arm semiconductor element VN are connected in series, 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 with each other.

[0018] A bus voltage is applied to the voltage applicator 3 through DC buses 35a and 35b. The voltage applicator 3 converts DC power from a power source 36, which is supplied through DC buses 35a and 35b, into AC power, and supplies the converted AC power to the rotating machine 1 to drive the rotating machine 1. Note that the current detector 2 is omitted in FIG. 2.

[0019] 2 illustrates an example in which 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 in anti-parallel to the transistor 30a. "Connected in anti-parallel" means that the anode side of the diode is connected to a first terminal corresponding to the source of the MOSFET, and the cathode side of the diode is connected to a second terminal corresponding to the drain of the MOSFET.

[0020] The semiconductor elements UP, UN, VP, VN, WP, and WN may be, for example, insulated gate bipolar transistors (IGBTs) instead of MOSFETs.

[0021] A connection point 32 between the upper arm semiconductor element UP and the lower arm semiconductor element UN is connected to a first phase, for example, the u-phase, of the rotating machine 1. A connection point 33 between the upper arm semiconductor element VP and the lower arm semiconductor element VN is connected to a second phase, for example, the v-phase, of the rotating machine 1. A connection point 34 between the upper arm semiconductor element WP and the lower arm semiconductor element WN is connected to a third phase, for example, the w-phase, of the rotating machine 1. In the voltage applicator 3, the connection points 32, 33, and 34 form AC terminals.

[0022] Here, we will explain the voltage vectors output by the voltage applicator 3. As mentioned above, the voltage applicator 3 is a three-phase PWM inverter, which is a power converter that obtains a desired voltage by PWM controlling the power source 36 supplied via DC buses 35a and 35b. The three-phase PWM inverter has two switching elements, one above the other, per phase, and operates so that one of the upper and lower switching elements is in the ON state. Therefore, in a three-phase triangular wave comparison inverter, there are 2 to the power of 3, or eight, switching states. Here, the states of the gate signals of the upper arms of the u-phase, v-phase, and w-phase in the voltage applicator 3 are respectively called G u ,G v ,G w Define G u ,G v ,G w When the value of is 1, it means that the semiconductor element of the upper arm of the corresponding phase is in a conducting state, and G u ,G v ,G w If the value of is 0, it means that the semiconductor element of the lower arm of the corresponding phase is in a conducting state. For example, (G u ,G v ,G w When the condition is (1,0,0), the semiconductor element of the upper arm of the u-phase is conductive, and the semiconductor elements of the lower arms of the v-phase and w-phase are conductive.

[0023] Here, the voltage vectors in the eight switching states of the voltage applicator 3 are defined as V0 to V7. FIG. 3 is a diagram showing an example of the correspondence between the switching states of each phase of the voltage applicator 3 shown in FIG. 1 and the definitions of the voltage vectors. (G u ,G v ,G w )=(0,0,0), the applied voltage vector is defined as V0, and (G u ,G v ,G w )=(1,0,0), the applied voltage vector is defined as V1, and (G u ,G v ,G w )=(1,1,0), the applied voltage vector is defined as V2, and (G u ,G v ,G w ) = (0,1,0), the applied voltage vector is defined as V3. u ,G v ,G w )=(0,1,1), the applied voltage vector is defined as V4, and (G u ,G v ,G w ) = (0,0,1), the applied voltage vector is defined as V5, and (G u ,G v ,G w )=(1,0,1), the applied voltage vector is defined as V6, and (G u ,G v ,G w The voltage vector applied under the condition of V) = (1,1,1) is defined as V7. Of these eight voltage vectors V0 to V7, the voltage vectors V0 and V7 are called zero voltage vectors, and the others, that is, the voltage vectors V1 to V6 are called effective voltage vectors. 0~7 Similarly, the effective voltage vectors V1 to V6 are expressed as the effective voltage vector V 1~6 It may be written as:

[0024] Fig. 4 is a diagram showing the eight switching states and voltage vectors shown in Fig. 3. Fig. 4 shows the voltage vectors in each switching state and the conduction state of each semiconductor element of the voltage applicator 3.

[0025] 5 is a diagram for explaining signal processing in the position estimator 4 shown in FIG. 1. The position estimator 4 estimates the rotating machine current i u ,i v ,i w and the gate signal G of the voltage applicator 3 u ,G v ,G w and calculates an estimated rotor position θ^, which is an estimate of the position of the rotor of the rotating machine 1. Specifically, the position estimator 4 has a current differential information calculation unit 40, a classifier 41, a DC component remover 42, a three-phase to two-phase converter 43, and a phase synchronization calculation unit 44.

[0026] The current differential information calculation unit 40 calculates current differential information corresponding to each of the effective voltage vectors V1 to V6. The current differential information calculation unit 40 calculates the current differential information corresponding to the u-phase, v-phase, and w-phase rotating machine current i u ,i v ,i w For each of the effective voltage vectors V1 to V6, the current differential information calculation unit 40 calculates current differential information corresponding to each of the effective voltage vectors V1 to V6. Therefore, the current differential information calculation unit 40 outputs 3×6=18 types of current differential information. The current differential information is also called the amount of change in the rotating machine current. The current differential information calculation unit 40 receives the gate signal G u ,G v ,G w and the rotating machine current i u ,i v ,i w is entered.

[0027] Fig. 6 is a diagram showing a detailed configuration of the current differential information calculation unit 40 shown in Fig. 5. 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 voltage vector determiner 400 that determines the type of the rotating machine current i u ,i v ,i wand a current differential calculator 401 that calculates current differential information of each phase corresponding to the effective voltage vector using the above.

[0028] Based on the definition shown in FIG. 3, the voltage vector determiner 400 calculates the gate signal G of the semiconductor device of the upper arm of each phase of the voltage applicator 3. u ,G v ,G w The voltage vector determiner 400 determines the type of voltage vector output by the voltage applicator 3 based on the gate signal G u ,G v ,G w The type of voltage vector is determined from the value of the voltage vector V 0~7 The voltage vector V 0~7 is output to the current differentiation calculator 401.

[0029] The current differentiation calculator 401 calculates the voltage vector V 0~7 and the rotating machine current i u ,i v ,i w and based on the effective voltage vector V 1~6 The current differential calculator 401 calculates the current differential information of each phase corresponding to the current voltage vector V 0~7 The type of the voltage vector and the type of the voltage vector from one control cycle ago are stored, and if the same effective voltage vector appears for two or more control cycles, the current differential information for each phase corresponding to the type of the effective voltage vector is calculated. The control cycle is set to a value that is sufficiently short compared 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 the effective voltage vector is being applied. N The type of voltage vector one control period before is V N , the current differential calculator 401 calculates V N The current differential information of the u-phase, v-phase, and w-phase when the uVN / dt", "di vVN / dt", "di wVN / dt", where N is an integer between 1 and 6. The current differential calculator 401 calculates V 1~6By distinguishing and calculating the six types of effective voltage vectors and three-phase current differential information, 18 types of current differential information "di uV1~6 / dt", "di vV1~6 / dt", "di wV1~6 / dt" is output.

[0030] Here, a total of 18 types of current differential information output by the current differential calculator 401 will be described. The current differential information includes a DC component and an AC component. FIG. 7 is a diagram showing the DC component and AC component included in the current differential information. In FIG. 7, for each of the 18 types of current differential information, a signal name, a mathematical expression indicating the DC component, and a mathematical expression indicating the AC component are associated. In the "signal name," u, v, and w indicate the corresponding phase of the rotating machine 1, and V1 to V6 indicate the type of the corresponding effective voltage vector.

[0031] The characteristics of the "DC component" of the current differential information shown in Figure 7 will be explained. Here, if A is defined by the following formula (1), the "DC component" of the current differential information occurs in the phase in the direction of the effective voltage vector with a magnitude of "2 / A", and occurs in the phases other than the phase in the direction of the effective voltage vector with a magnitude of "1 / A" with an opposite sign. Therefore, the sum of the DC component of the u phase, the DC component of the v phase, and the DC component of the w phase when the same effective voltage vector is applied is zero. Here, V dc is the DC voltage of the power source 36 of the voltage applicator 3.

[0032]

number

[0033] L0 in formula (1) is expressed by the following formula (2). Also, L1 in 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.

[0034]

number

[0035]

number

[0036] Next, we will explain the characteristics of the "AC component" of the current differential information. 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 formula (4), the AC component of the current differential information of the v phase is expressed by formula (5), and the AC component of the current differential information of the w phase is expressed by formula (6).

[0037]

number

[0038]

number

[0039]

number

[0040] As shown in equations (4) to (6), the current differential information obtained by applying an effective voltage vector contains information about the rotor position θ. The "AC component" column in Figure 7 shows the expansion of the phases in equations (4) to (6). As is clear from Figure 7 and equations (4) to (6), the AC components of the current differential information during the period when the same effective voltage vector is applied have a phase difference of ±2π / 3, and each reference phase shifts depending on the application direction of the effective voltage vector. The magnitude of the amplitude of the AC component is the same for all combinations of effective voltage vectors and phases, and is equal to (1 / A) × (L1 / L0). Note that the magnitude relationship between the d-axis and q-axis inductance differs between an interior permanent magnet synchronous motor (IPMSM) and a synchronous reluctance motor, so the value of the cosine function coefficient "(1 / A) × (L1 / L0)" is a positive value for an interior permanent magnet synchronous motor and a negative value for a synchronous reluctance motor.

[0041] In each phase, the current differential information obtained by combinations of effective voltage vectors that are in a magnetization and demagnetization direction relationship have opposite signs, as expressed in the following equations (7) to (9). In equations (7) to (9), n is an integer between 1 and 3. The combinations of voltage vectors that are in a magnetization and demagnetization direction relationship are V1 and V4 in the u-phase, V3 and V6 in the v-phase, and V5 and V2 in the w-phase.

[0042]

number

[0043]

number

[0044]

number

[0045] FIG. 8 shows the output of the current differential information calculation unit 40 shown in FIG. 5. FIG. 8 shows simulation results for current vector control of a synchronous reluctance motor rotating at low speed. The PWM of the voltage applicator 3 uses a commonly used triangular wave carrier comparison common to all three phases. For ease of explanation, the voltage vector numbers V0 and V7 are numbered 0. Focusing on the rotor position and the numbers of the applied voltage vectors, a correlation can be confirmed between the rotor position and the voltage vector appearance pattern. During the period when a specific effective voltage vector appears, current differential information corresponding to other effective voltage vectors cannot be obtained. Therefore, in the appearance pattern of an effective voltage vector in which a specific effective voltage vector occurs over a long period of time, the current differential information is fragmented. Furthermore, the timing at which each piece of current differential information can be obtained varies, resulting in different delays depending on the signal. Due to this characteristic, signal processing without considering the voltage vector appearance pattern can result in unstable position sensorless control. Here, "signal processing is performed without taking into consideration the appearance pattern of voltage vectors" refers to, for example, fixing the type of current differential information used to estimate the rotor position regardless of the type of voltage vector that appears.

[0046] For this reason, the position estimator 4 performs signal processing to generate AC components of continuous current differential information having rotor position information from the fragmented 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 characteristic, the same waveform shape appears in the current differential information under different voltage vector and phase conditions. For this reason, the position estimator 4 uses the waveform shapes that appear under different voltage vector and phase conditions to interpolate the fragmented current differential information and generate AC components of continuous current differential information.

[0047] Returning to the explanation of Fig. 5, classifier 41 classifies the current differential information output by current differential information calculation unit 40 into one of six types of signals based on the magnitude and reference phase of the DC component. Based on the characteristics of the above formulas (4) to (9), classifier 41 classifies the signals into six types based on the magnitude of the DC component and the phase of the AC component: group (2 / A, 0°), group (-1 / A, 120°), group (-1 / A, -120°), group (2 / A, -120°), group (-1 / A, 0°), and group (2 / A, 120°).

[0048] 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" for each of the six groups classified by the classifier 41. Here, "group" indicates the name of the group, and a group described 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 for the cosine component of the AC component, "cos(2θ+2π / 3)," in FIG. 9 is 2π / 3 [rad] = 120 [°]. The "symbol" indicates signals with the same waveform. For example, in the group (2 / A, 0°), the waveform of the current differential information of the u-phase when the effective voltage vector V1 is applied is the same as the waveform of the current differential information of the u-phase when the effective voltage vector V4 is applied.

[0049] FIG. 10 is a diagram illustrating the operation of the classifier 41 shown in FIG. 5. The classifier 41 uses the current differential information "di uV1~6 / dt", "di vV1~6 / dt", "di wV1~6When "di / dt" is input, six types of signals are generated based on the classification shown in FIG. 9. Specifically, the classifier 41 prepares variables corresponding to each of the six types of groups, and operates to assign the current differential information to the variable of the group into which the current differential information input to the classifier 41 is classified, while retaining the previous values ​​of the variables of the other groups. Here, for the sake of explanation, the names of the 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" and "-di" under the condition that V4 is applied. uV4 / dt" is substituted, and when an effective voltage vector other than V1 and V4, i.e., V2, V3, V5, or V6, is applied, the previous value is maintained. Similarly, the classifier 41 assigns "di vV1 / dt" and "-di" under the condition that V4 is applied. vV4 / dt" and "di uV3 / dt" and "-di" under the condition that V6 is applied. uV6 / dt" is substituted, and when V2 and V5 are applied, the previous value is maintained.

[0050] Returning to the explanation of FIG. 5 , the DC component remover 42 extracts a DC component from the output of the classifier 41 and subtracts the DC component from current differential information obtained by applying the latest effective voltage vector, thereby generating a continuous AC component. In the first embodiment, an example of extracting a DC component using a three-phase balance condition will be described. To extract the DC component "1 / A" using the three-phase balance condition, the following mathematical expressions (10) to (14) are used. That is, the DC component remover 42 calculates the sum of signals of combinations with phases of 0°, 120°, and −120° from the output of the classifier 41, and multiplies the sum by a coefficient for conversion to a DC component to calculate the DC component. Although five types of mathematical expressions (10) to (14) are shown here, the DC component remover 42 may perform the calculation using at least one appropriate mathematical expression depending on the combination of the latest effective voltage vector and the most recent effective voltage vector having a different number from the latest effective voltage vector.

[0051]

number

[0052]

number

[0053]

number

[0054]

number

[0055]

number

[0056] Specifically, the DC component remover 42 uses one of the formulas (10) to (14) that uses the latest effective voltage vector and the most recent effective voltage vector with a different number from the latest effective voltage vector. Here, for example, group (2 / A, 0°) is generated based on the current differential information when the effective voltage vector V1 or V4 is applied, group (2 / A, 120°) is generated based on the current differential information when the effective voltage vector V5 or V2 is applied, and group (2 / A, -120°) is generated based on the current differential information when the effective voltage vector V3 or V6 is applied. Therefore, formula (10) can be said to be a formula that uses the effective voltage vectors V1 or V4, V5 or V2, and V3 or V6. Similarly, formula (11) is a formula that uses the effective voltage vectors V2 or V5 and V1, V3, V4, or V6. Equation (12) uses the effective voltage vectors V1 or V4 and V2 or V5. Equation (13) uses the effective voltage vectors V1 or V4 and V3 or V6. Equation (14) uses the effective voltage vectors V2 or V5 and V3 or V6.

[0057] For example, if the combination of the latest effective voltage vector and the most recent effective voltage vector with a different number from the latest effective voltage vector is V1 and V2, at least one equation using these voltage vectors can be selected from equations (10) to (14). The equations using the effective voltage vectors V1 and V2 are equations (11) and (12). Therefore, the DC component remover 42 calculates the DC component "1 / A" using at least one of equations (11) and (12). When multiple equations are used, the DC component remover 42 can calculate the DC component "1 / A" using the average value of the calculation results of each of the multiple equations.

[0058] 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, thereby calculating the AC component of the latest current differential information. The DC component remover 42 can calculate the AC component of the latest current differential information using the following equations (15) to (17). The DC component remover 42 selects one of the equations (15) to (17) based on the type of the latest voltage vector.

[0059]

number

[0060]

number

[0061]

number

[0062] The DC component remover 42 outputs the calculation results, group (0, 0°), group (0, 120°), and group (0, -120°), to the three-phase to two-phase converter 43. The outputs of the DC component remover 42, group (0, 0°), group (0, 120°), and group (0, -120°), are continuous AC components that contain rotor position information. Below, a method for calculating the rotor position using these AC components will be explained. To calculate the rotor position from AC components that have a phase difference of ±2π / 3 from each other, there are several methods, such as performing a three-phase to two-phase transformation on these AC components and performing an arctangent calculation, or performing a phase synchronous calculation on the three-phase to two-phase transformation results to estimate the rotor position. Here, the method for estimating the rotor position using phase synchronous calculation will be explained as an example.

[0063] The three-phase to two-phase converter 43 calculates the α-axis AC component α and β-axis AC component β, which are AC components on two orthogonal axes. The three-phase to two-phase converter 43 calculates the α-axis AC component α and β-axis AC component β using the following equation (18), and outputs the calculated α-axis AC component α and β-axis AC component β to the phase synchronization calculation unit 44.

[0064]

number

[0065] 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 by the three-phase to 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.

[0066] Fig. 11 is a block diagram showing the configuration of the phase synchronization calculation unit 44 shown in Fig. 5. The phase synchronization calculation unit 44 has a phase error calculation unit 441, a PI (Proportional Integral) controller 442, an integrator 443, and proportional units 444 and 445.

[0067] The phase error calculation unit 441 receives the α-axis AC component α and the β-axis AC component β output from the three-phase to two-phase converter 43, and the estimated rotor position 2θ^ output from the integrator 443. The phase error calculation unit 441 calculates the phase error Δi AC *Δ2θ. The phase error calculation unit 441 calculates the calculated phase error Δi AC *Δ2θ is output to the PI controller 442.

[0068]

number

[0069] Here, "Δi AC " is expressed by the following equation (20).

[0070]

number

[0071] The PI controller 442 receives the phase error Δi AC *Δ2θ is input. The PI controller 442 calculates the phase error Δi AC *Output the estimated speed 2ω^ so that Δ2θ becomes zero.

[0072] 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 by the integrator 443 is fed back to the phase error calculation unit 441.

[0073] In the above equation (19), when "2θ>2θ^", the phase error Δi AC *Since Δ2θ is a positive value, the estimated speed 2ω^ and estimated rotor position 2θ^ are corrected in the increasing direction. Also, when "2θ<2θ^", the phase error Δi AC *Since Δ2θ is a negative value, the estimated speed 2ω^ and estimated rotor position 2θ^ are corrected to decrease. Ultimately, "2θ = 2θ^" is obtained, 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 synchronization calculation unit 44 takes the form of a phase locked loop (PLL).

[0074] The phase synchronization calculation unit 44 inputs the estimated rotor position 2θ^ to a proportional unit 444 and multiplies it by 0.5 to calculate an estimated rotor position θ^. The phase synchronization calculation unit 44 also inputs the estimated speed 2ω^ to a proportional unit 445 and multiplies it by 0.5 to calculate an estimated speed ω^.

[0075] FIG. 12 shows the output of each component of the position estimator 4 shown in FIG. 5. In FIG. 12, the operating conditions are the same as those in FIG. 8, which are conditions under which the current differential information is fragmented. The "Rotor Position" section in the first row from the top of FIG. 12 shows the true rotor position 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 unit 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 to 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, as in FIG. 8, for the sake of explanation, the voltage vectors V0 and V7 are numbered 0 in FIG. 12.

[0076] 12, it can be seen that the classifier 41 generates six types of signals based on the classification shown in Fig. 9. The output of the DC component remover 42 has zero DC components and is an AC component expressed on two orthogonal axes that oscillate at an angle twice the rotor position. The position estimator 4 estimates the rotor position by performing phase synchronous calculation on the output of the three-phase to two-phase converter 43.

[0077] Returning to the explanation of FIG. 1, the three-phase to two-phase converter 9 of the controller 5 receives the rotating machine current i detected by the current detector 2. u ,i v ,i w The three-phase to two-phase converter 9 calculates the rotating machine current i u ,i v ,i w The rotating machine current i on the stationary two-phase coordinate system α ,i β The three-phase to two-phase converter 9 converts the rotating machine current i α ,i β is output to the rotational coordinate converter 10.

[0078] The rotating coordinate converter 10 receives the rotating machine current i output from the three-phase to two-phase converter 9. α ,i βand the estimated rotor position θ^ output by the position estimator 4. The rotating coordinate converter 10 uses the estimated rotor position θ^ to convert the rotating machine current i α ,i β The rotating machine current i on the rotating coordinate system d ,i q The rotating coordinate converter 10 converts the rotating machine current i d ,i q is output to the current controller 6.

[0079] The current controller 6 receives the rotating machine current command i d *,i q * and the rotating machine current i d ,i q The rotating machine current command i d * is a command for the d-axis driving current, which indicates the armature current component in the d-axis direction at which the magnetic resistance of the rotor of the rotating machine 1 is minimum. q * is a command for the q-axis drive current, which indicates the armature current component in one axis direction, which is perpendicular to the d-axis. The current controller 6 controls the rotating machine current i d ,i q is the rotating machine current command i d *,i q *, and the rotating machine voltage command v d *,v q The current control in the current controller 6 is, for example, PI control. The current controller 6 calculates the rotating machine voltage command v d *,v q * is output to the rotation coordinate inverse converter 7.

[0080] The rotating coordinate inverse converter 7 receives the rotating machine voltage command v d *,v q The rotating coordinate inverse converter 7 uses the estimated rotor position θ^ to convert the rotating machine voltage command v in the rotating coordinate system calculated by the current controller 6. d *,v q * is the rotating machine voltage command v on the stationary two-phase coordinate system α *,v β The rotating coordinate inverse converter 7 converts the rotating machine voltage command v α *,vβ * is output to the two-phase to three-phase converter 8.

[0081] The two-phase to three-phase converter 8 receives the rotating machine voltage command v α *,v β The two-phase to three-phase converter 8 receives the rotating machine voltage command v on the stationary two-phase coordinate system. α *,v β * is the rotating machine voltage command v on the three-phase coordinate system to drive the rotating machine 1. u *,v v *,v w Convert to *.

[0082] As described above, the control device 100 according to the first embodiment is a control device 100 that performs drive control of a multi-phase rotating machine 1, and includes a current detector 2 that is 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 information on the rotating machine current and the rotor position of the rotating machine 1, a voltage applicator 3 that applies a voltage to the rotating machine 1 based on the generated drive voltage command, and a position estimator 4 that is a position estimator that estimates the rotor position based on the rotating machine current detected by the current detector 2. The position estimator 4 calculates a gate signal G u ,G v ,G w The control device 100 determines the type of voltage vector output by the voltage applicator 3 based on the current differential information, calculates current differential information which is the amount of change in the rotating machine current for each type of determined voltage vector, generates an AC signal whose DC component is zero and which varies at twice the angle of the rotor position from the amount of change in the rotating machine current which is the calculation result, and estimates the rotor position based on the generated AC signal. With this configuration, even in an appearance pattern of an effective voltage vector in which the current differential information is fragmented, the control device 100 can estimate the rotor position with high accuracy by generating a continuous AC signal whose DC component is zero and which oscillates at twice the angle of the rotor position from the fragmented current differential information.

[0083] The position estimator 4 can estimate the rotor position by, for example, performing phase-synchronous calculation on the generated AC signal. Furthermore, the position estimator 4 generates an AC signal with a continuous waveform based on a combination of multiple pieces of current differential information having the same waveform, among multiple pieces of current differential information obtained under multiple conditions in which at least one of the voltage vector and the phase is different. More specifically, the position estimator 4 utilizes the characteristic that two pieces of current differential information obtained under conditions in which the voltage vector directions are opposite to each other and the same phase have opposite signs to each other, and can generate a continuous AC signal using a value obtained by multiplying one of the two pieces of current differential information obtained under conditions in which the voltage vector directions are opposite to each other and the same phase by minus one.

[0084] 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.

[0085] Furthermore, as shown in the above formulas (10) to (14), the position estimator 4 can calculate the DC component of the current differential information by taking the sum of the first current differential information, the second current differential information having a phase difference of plus 2 / 3π with respect to the first current differential information, and the third current differential information having a phase difference of minus 2 / 3π with respect to the first current differential information.

[0086] The position estimator 4 also has a phase error calculation unit 441 that calculates a phase error based on the estimated rotor position and an AC signal that has zero DC component and changes at twice the angle of the rotor position, a PI controller 442 that is an estimated speed generation unit that outputs an estimated speed based on the phase error, and an integrator 443 that outputs a value obtained by integrating the estimated speed as an estimated position.

[0087] Embodiment 2 The control device 100 according to the second embodiment has the same configuration as that of the first embodiment. In the second embodiment, the overall configuration of the control device 100 is the same as that shown in FIG. 1, and the configuration of the position estimator 4 is the same as that shown in FIG. 5. Therefore, the same reference numerals as those in the first embodiment will be used in the description of the second embodiment. However, in the second embodiment, the processing content performed by the DC component remover 42 shown in FIG. 5 differs from that in the first embodiment. The following mainly describes the parts that differ from the first embodiment.

[0088] In the second embodiment, the DC component remover 42 calculates the DC component "1 / A" using the following equations (21) to (23) instead of the above equations (10) to (14).

[0089]

number

[0090]

number

[0091]

number

[0092] In Equations (21) to (23), the DC component "1 / A" is calculated by taking the difference between signals output from the classifier 41 that have different DC components and the same reference phase for the AC component. Although three Equations (21) to (23) are shown here, the DC component remover 42 may use at least one equation that uses the latest effective voltage vector and the most recent effective voltage vector with a different number from the latest effective voltage vector. For example, group (2 / A, 0°) is generated based on the current differential information when the effective voltage vector V1 or V4 is applied, and group (-1 / A, 0°) is generated based on the current differential information when the effective voltage vector V2, V3, V5, or V6 is applied. Therefore, Equation (21) can be said to be an equation that uses the effective voltage vector V1 or V4 and V2, V3, V5, or V6. Similarly, equation (22) is an equation using the effective voltage vectors V2 or V5 and V1 or V3 or V4 or V6, and equation (23) is an equation using the effective voltage vectors V3 or V6 and V1 or V2 or V4 or V5.

[0093] For example, if the latest effective voltage vector and the most recent effective voltage vector with a different number from the latest effective voltage vector are effective voltage vectors V1 and V2, the calculation is performed using at least one of Equation (21) and Equation (22) that use the effective voltage vectors V1 and V2. As in the first embodiment, when multiple equations are used, the DC component remover 42 can calculate the DC component "1 / A" using the average value of the calculation results of each of the multiple equations. As described above, in the second embodiment, the process of extracting the DC component differs from that in the first embodiment, but the other processes are the same as those in the first embodiment. In the second embodiment, as in the first embodiment, the control device 100 can estimate the rotor position with high accuracy even in an appearance pattern of an effective voltage vector in which the current differential information is fragmented by generating a continuous AC signal with zero DC component and oscillating at twice the angle of the rotor position from the fragmented current differential information.

[0094] Furthermore, while the formulas (10) to (14) used in the first embodiment require three signals from the output of the classifier 41, the formulas (21) to (23) used in the second embodiment can calculate the DC component "1 / A" using two signals from the output of the classifier 41. Therefore, the second embodiment has the advantage of reducing the calculation load compared to the first embodiment. Furthermore, the method using the formulas (21) to (23) requires the application of two types of voltage vectors, while the method using the formulas (10) to (14) requires the application of two or three types of voltage vectors. From the perspective of position estimation response, the fewer the types of voltage vectors used in the calculation, the better the response. Therefore, the second embodiment can extract the DC component with higher response than the method of the first embodiment.

[0095] Next, a description will be given of a hardware configuration for realizing each function of the control device 100 according to the first and second embodiments. The functions referred to here refer to the functions of the current detector 2, the voltage applicator 3, the position estimator 4, and the controller 5.

[0096] FIG. 13 is a diagram illustrating a first example of a hardware configuration for implementing the functions of the control device 100 according to the first and second embodiments. FIG. 14 is a diagram illustrating a second example of a hardware configuration for implementing the functions of the control device 100 according to the first and second embodiments. In the first example illustrated in FIG. 13, the control device 100 includes a dedicated processing circuit 1000, a current detector 2, and a voltage applicator 3. The functions of the current detector 2 and the voltage applicator 3 are implemented using dedicated hardware, and the functions of the position estimator 4 and the controller 5 are implemented by the dedicated processing circuit 1000. In the second example illustrated in FIG. 14, the control device 100 includes a processor 1001, a storage device 1002, the current detector 2, and the voltage applicator 3. The functions of the current detector 2 and the voltage applicator 3 are implemented using dedicated hardware, and the functions of the position estimator 4 and the controller 5 are implemented by the processor 1001 and the storage device 1002. The dedicated processing circuit 1000 and the processor 1001 are also referred to as control circuits.

[0097] The dedicated processing circuit 1000 may be 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 all of the above functions using a single dedicated processing circuit 1000, or may implement each of the above functions using multiple dedicated processing circuits 1000.

[0098] The processor 1001 can realize each function of the control device 100 by reading and executing a program stored in the storage device 1002. Note that the control device 100 may realize each of the above-described functions by cooperation between a plurality of processors 1001 and a plurality of storage devices 1002.

[0099] When the processor 1001 and the storage device 1002 are used, each of the above-described functions is realized by software, firmware, or a combination of these. The software or firmware is written as a program and stored in the storage device 1002. The processor 1001 reads and executes the program stored in the storage device 1002. It can also be said that these programs cause the computer to execute the procedures and methods for executing each function.

[0100] The processor 1001 is a CPU, and is also called a processing unit, an arithmetic unit, a microprocessor, a microcomputer, a DSP (Digital Signal Processor), etc. The storage device 1002 is, for example, a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable ROM), or an EEPROM (registered trademark) (Electrically EPROM), a magnetic disk, a flexible disk, an optical disk, a compact disk, a minidisk, or a DVD (Digital Versatile Disk).

[0101] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0102] For example, in the above-described first and second embodiments, 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 also be a motor with salient poles, such as an interior permanent magnet synchronous motor or a surface permanent magnet synchronous motor (SPMSM).

[0103] Furthermore, in the above-described first and second embodiments, the controller 5 of the control device 100 controls the d-axis current and the q-axis current, but the controller 5 can also be configured to control the torque, rotational speed, etc.

[0104] Furthermore, in the above-described first and second embodiments, the current detector 2 detects the phase current of the rotating machine 1. However, the current detector 2 is an example of a current detection unit and is not limited to the above example. The current detection unit may be a current sensor built into an inverter (not shown) that configures the voltage applicator 3, as long as it can detect the phase current. [Explanation of symbols]

[0105] 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 to three-phase converter, 9, 43 three-phase to 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 calculator, 441 phase error calculation unit, 442 PI controller, 443 integrator, 444, 445 proportional controller, 1000 dedicated processing circuit, 1001 processor, 1002 Memory devices, UP, UN, VP, VN, WP, WN semiconductor elements.

Claims

1. A control device for driving and controlling a multi-phase rotating machine having salient poles, comprising: 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 a rotor position of the rotating machine; a voltage applicator that applies a 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 the type of voltage vector output by the voltage applicator based on a gate signal of the voltage applicator, calculates a change in the rotating machine current for each determined type of voltage vector, generates an AC signal having zero DC component and changing at twice the angle of the rotor position based on the calculated change in the rotating machine current, and estimates the rotor position based on the AC signal. A control device characterized by:

2. The position estimation unit estimates the rotor position by performing a phase synchronous operation on the AC signal.

2. The control device according to claim 1.

3. The position estimation unit generates the AC signal having a continuous waveform shape based on a combination of a plurality of the rotating machine current change amounts including the same waveform shape among a plurality of the rotating machine current change amounts obtained under a plurality of conditions in which at least one of a voltage vector and a phase is different.

2. The control device according to claim 1.

4. The position estimation unit utilizes a feature that the two rotating machine current change amounts obtained under the same phase condition with the voltage vectors in opposite directions to each other have opposite signs to each other, and generates the AC signal using a value obtained by multiplying one of the two rotating machine current change amounts obtained under the same phase condition with the voltage vectors in opposite directions to each other by minus one.

4. The control device according to claim 3.

5. The position estimation unit generates the AC signal by utilizing a characteristic that the phase of the AC component of the amount of change in the rotating machine current shifts depending on the direction of the voltage vector.

4. The control device according to claim 3.

6. The position estimation unit calculates a DC component of the amount of change in the rotating machine current, calculates an AC component of the amount of change in the rotating machine current by subtracting the calculated DC component from the amount of change in the rotating machine current, and generates the AC signal based on the AC component.

6. The control device according to claim 3, wherein the control device is a control unit for controlling a vehicle.

7. The position estimation unit calculates the DC component by taking the sum of a first rotating machine current change amount, a second rotating machine current change amount having a phase difference of plus 2 / 3π with respect to the first rotating machine current change amount, and a third rotating machine current change amount having a phase difference of minus 2 / 3π with respect to the first rotating machine current change amount, among the rotating machine current change amounts.

7. The control device according to claim 6.

8. The position estimation unit calculates the DC component by taking a difference between two of the rotating machine current change amounts, which have the same phase of the AC component but different magnitude of the DC component.

7. The control device according to claim 6.

9. The position estimation unit a phase error calculation unit that calculates a phase error based on the AC signal having zero DC component and changing at twice the angle of the rotor position and the estimated rotor position; an estimated velocity generating unit that outputs an estimated velocity based on the phase error; an integrator that outputs a value obtained by integrating the estimated velocity as the estimated position; have 2. The control device according to claim 1.

10. A drive control method for a polyphase rotating machine having salient poles, 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 a 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, a type of voltage vector output by a voltage applicator that applies a voltage to the rotating machine is determined based on a gate signal of the voltage applicator, a change amount of the rotating machine current is calculated for each determined type of voltage vector, an AC signal having zero DC component and changing at twice the angle of the rotor position is generated based on the calculated change amount of the rotating machine current, and the rotor position is estimated based on the AC signal. A drive control method characterized by:

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