Inverter control device and synchronous machine drive device

Abstract

An inverter control device and a synchronous machine drive device that suppress deterioration in reliability and comfort are provided. [Solution] An inverter control device 100 according to an embodiment includes a voltage command generation unit 102 that generates a voltage command to be applied to a synchronous machine M, a current detection unit 101 that detects the current flowing from the inverter main circuit INV driven by a gate command based on the voltage command to the synchronous machine M, a flag generation unit 108 that switches between motor parameter tuning operation and normal operation operation, and a parameter calculation unit 107 that calculates motor parameters using the voltage command value and the detection value of the current detection unit 101 during motor parameter tuning operation, and the voltage command generation unit 102 generates a voltage command to apply a DC voltage to the synchronous machine M during motor parameter tuning operation.

Description

[Technical Field]

[0001] An embodiment of the present invention relates to an inverter control device and a synchronous machine driving device. [Background technology]

[0002] When driving a synchronous machine using an inverter, motor parameters are required. Conventionally, in addition to methods for obtaining the motor parameters of a synchronous machine by obtaining data such as motor winding resistance and inductance through pre-testing, methods for automatic acquisition (auto-tuning) have also been proposed. Auto-tuning eliminates the need for pre-testing to obtain data, shortening the time until the synchronous machine can be put into operation.

[0003] For example, methods that have been proposed include passing a three-phase unbalanced AC voltage through a synchronous machine and obtaining motor parameters (motor winding resistance, inductance) from the frequency components of this AC current; superimposing a high-frequency signal on the signal applied to the synchronous machine and observing the response to obtain differential inductance corresponding to the harmonics, from which the average inductance corresponding to the fundamental wave is calculated to obtain motor parameters; and passing DC and AC current through a synchronous machine to calculate motor parameters. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-262643 [Patent Document 2] Special Publication No. 2019-537412 [Patent Document 3] Japanese Patent Application Publication No. 2020-010477 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when applying a three-phase unbalanced AC voltage to a synchronous machine, the synchronous machine tends to rotate when the frequency of the AC voltage is lowered, and noise occurs when the frequency is increased, making it difficult to stably obtain motor parameters and potentially reducing reliability.Furthermore, when a high-frequency signal is applied to a synchronous machine, vibrations may occur in addition to noise due to the superposition of the high-frequency signal.

[0006] The embodiments of the present invention have been made in consideration of the above circumstances, and an object of the present invention is to provide an inverter control device and a synchronous machine driving device that suppress a decrease in reliability and comfort. [Means for solving the problem]

[0007] An inverter control device according to an embodiment includes a voltage command generation unit that generates a voltage command to be applied to a synchronous machine, a current detection unit that detects a current flowing from an inverter main circuit driven by a gate command based on the voltage command to the synchronous machine, a flag generation unit that switches between a motor parameter tuning operation and a normal operation operation, and a parameter calculation unit that calculates motor parameters using the voltage command value and the detection value of the current detection unit during the motor parameter tuning operation, and the voltage command generation unit generates a voltage command to apply a DC voltage to the synchronous machine during the motor parameter tuning operation. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram schematically illustrating an example of the configuration of an inverter control device and a synchronous machine driving device according to a first embodiment. [Figure 2] FIG. 2 is a diagram schematically illustrating an example of a synchronous machine driven by the synchronous machine driving device of the embodiment. [Figure 3] FIG. 3 is a diagram for explaining the definitions of a rotating coordinate system (d-axis, q-axis) and an estimated rotating coordinate system (dc-axis, qc-axis) in one embodiment. [Figure 4] FIG. 4 is a diagram schematically illustrating an example of the configuration of the flag generation unit illustrated in FIG. [Figure 5]FIG. 5 is a diagram schematically illustrating an example of the configuration of the rotation determining unit shown in FIG. [Figure 6] FIG. 6 is a diagram schematically illustrating an example of a flag generated by the generating unit. [Figure 7] FIG. 7 is a block diagram schematically showing an example of the configuration of the parameter calculation function unit of the voltage command generation unit. [Figure 8] FIG. 8 is a block diagram schematically showing an example of the configuration of the normal operation function unit of the voltage command generation unit. [Figure 9] FIG. 9 is a diagram schematically illustrating an example of the configuration of the high-frequency voltage superimposing unit shown in FIG. [Figure 10] FIG. 10 is a diagram schematically illustrating an example of the configuration of the rotation angle / speed calculation unit shown in FIG. [Figure 11] FIG. 11 is a diagram schematically illustrating an example of the configuration of a harmonic current detection unit of the rotation speed estimation unit shown in FIG. [Figure 12] FIG. 12 is a diagram illustrating an example of the operation of the band-pass filter. [Figure 13] FIG. 13 is a diagram illustrating an example of the operation of the FFT analysis unit. [Figure 14] FIG. 14 is a diagram illustrating an example of the operation of the FFT analysis unit. [Figure 15] FIG. 15 is a diagram schematically illustrating an example of the configuration of the parameter calculation unit shown in FIG. [Figure 16] FIG. 16 is a flowchart illustrating an example of the operation of the inverter control device and the synchronous machine driving device of the first embodiment. [Figure 17] FIG. 17 is a flowchart illustrating an example of a parameter tuning operation in the inverter control device and the synchronous machine driving device of the first embodiment. [Figure 18] FIG. 18 is a diagram illustrating an example of table data generated by the parameter calculation unit shown in FIG. [Figure 19] FIG. 19 is a diagram for explaining a first modified example of table data generated by the parameter calculation unit shown in FIG. [Figure 20] FIG. 20 is a diagram for explaining a second modified example of the table data generated by the parameter calculation unit shown in FIG. [Figure 21] FIG. 21 is a block diagram schematically showing an example of the configuration of an inverter control device and a synchronous machine driving device according to the second embodiment. [Figure 22] FIG. 22 is a diagram schematically illustrating an example of a flag generated by the flag generating unit illustrated in FIG. [Figure 23] FIG. 23 is a block diagram schematically showing an example of the configuration of the rotation determination unit of the flag generation unit shown in FIG. [Figure 24] FIG. 24 is a block diagram schematically showing an example of the configuration of the voltage command generating unit shown in FIG. [Figure 25] FIG. 25 is a block diagram schematically showing an example of the configuration of the rotation angle / speed calculation unit shown in FIG. [Figure 26] FIG. 26 is a flowchart illustrating an example of the operation of the inverter control device and the synchronous machine driving device of the second embodiment. [Figure 27] FIG. 27 is a diagram schematically showing a configuration of a resistance calculation unit of the parameter calculation unit shown in FIG. [Figure 28] FIG. 28 is a flowchart illustrating an example of the operation of the inverter control device and the synchronous machine driving device according to the modified example of the second embodiment. [Figure 29] FIG. 29 is a diagram showing an example of timing for latching the motor winding resistance value in the parameter calculation unit of the inverter control device according to the modified example of the second embodiment. [Figure 30] FIG. 30 is a block diagram schematically showing a configuration example of an inverter control device and a synchronous machine driving device according to the third embodiment. [Figure 31] FIG. 31 is a block diagram schematically showing an example of the configuration of the voltage command generating unit shown in FIG. [Figure 32] FIG. 32 is a block diagram schematically showing an example of the configuration of the parameter calculation unit shown in FIG. [Figure 33]FIG. 33 is a diagram schematically illustrating an example of a flag generated by the flag generating unit illustrated in FIG. [Figure 34] FIG. 34 is a flowchart illustrating an example of the operation of the inverter control device and the synchronous machine driving device of the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] An inverter control device and a synchronous machine driving device according to an embodiment will be described below with reference to the drawings. FIG. 1 is a diagram schematically illustrating an example of the configuration of an inverter control device and a synchronous machine driving device according to a first embodiment.

[0010] The synchronous machine driving device of the first embodiment includes an inverter main circuit INV and an inverter control device 100. The inverter main circuit INV converts DC power into three-phase AC power and outputs it to the synchronous machine M. The inverter main circuit INV includes an upper arm switching element and a lower arm switching element in each phase.

[0011] The inverter main circuit INV receives control signals (gate commands) for the upper and lower arm switching elements from the inverter control device 100. The inverter main circuit INV can convert AC power and DC power mutually by switching the switching elements on and off.

[0012] The synchronous machine M is, for example, a motor having magnetic salient poles, such as a permanent magnet synchronous motor (PMSM) or a synchronous reluctance motor (SynRM). In this embodiment, an example in which a SynRM is used as the synchronous machine M will be described.

[0013] FIG. 2 is a diagram schematically illustrating an example of a synchronous machine driven by the synchronous machine driving device of the embodiment. Here, the configuration of a SynRM is shown as an example of a synchronous machine M. The synchronous machine M includes a rotor 20 and a stator 10, and a magnetic field is generated by three-phase AC current flowing through each excitation phase, and torque is generated by magnetic interaction with the rotor 20. Note that only a part of the synchronous machine M is shown here, and the stator 10 and rotor 20 of the synchronous machine M are, for example, a combination of multiple configurations shown in Fig. 2.

[0014] The rotor 20 has an air gap 21, a peripheral bridge BR1, and a center bridge BR2. The center bridge BR2 is arranged on a line connecting the outer periphery and center of the rotor 20. The line on which the center bridges BR2 are arranged corresponds to the d-axis. The outer periphery bridge BR1 is located between the outer periphery of the rotor 20 and the air gaps 21. The synchronous machine M shown in FIG. 2 has six air gaps 21 extending between the outer periphery and center of the rotor 20. The air gaps 21 extend between the center bridge BR2 and the outer periphery bridge BR1, symmetrically with respect to the d-axis.

[0015] FIG. 3 is a diagram for explaining the definitions of a rotating coordinate system (d-axis, q-axis) and an estimated rotating coordinate system (dc-axis, qc-axis) in one embodiment. In this embodiment, the d-axis is the axis where the magnetic saliency decreases, and the q-axis is the axis where the magnetic saliency increases. The dc-axis is the d-axis in the estimated rotating coordinate system, and the qc-axis is the q-axis in the estimated rotating coordinate system.

[0016] The d-axis is a vector axis rotated by a rotational phase angle θ from the α-axis (U-phase) of the αβ fixed coordinate system, and the q-axis is a vector axis orthogonal to the d-axis in terms of electrical angle. In contrast, the dcqc estimated rotating coordinate system corresponds to the d-axis and q-axis at the estimated position of the rotor 20. That is, the dc-axis is the vector axis rotated by the rotational phase angle estimated value θest (θ in FIG. 1) from the α-axis. e The qc-axis is a vector axis rotated by an electrical angle (corresponding to the estimated error Δθ) from the d-axis, and the qc-axis is a vector axis that is orthogonal to the dc-axis in electrical angle. In other words, the vector axis rotated by the estimated error Δθ from the d-axis is the dc-axis, and the vector axis rotated by the estimated error Δθ from the q-axis is the qc-axis.

[0017] The inverter control device 100 includes a calculation device having at least one processor, such as a CPU or an MPU, and a memory storing a program executed by the processor. The inverter control device 100 can realize the various functions described below by software or a combination of software and hardware.

[0018] The inverter control device 100 receives a torque command T dref The upper controller controls the equipment equipped with the synchronous machine M and the inverter main circuit INV so that multiple components operate in coordination. The upper controller is equipped with a user interface such as an operation panel, and obtains a torque command T based on the operation of the user interface. dref may be output to the inverter control device 100.

[0019] The inverter control device 100 includes a current command generating unit 101, a voltage command generating unit 102, a coordinate (dq / 3Φ) conversion unit 103, a modulation unit 104, a coordinate (3Φ / dq) conversion unit 105, a rotation angle / speed calculation unit 106, a parameter calculation unit 107, a flag generation unit 108, a high-frequency voltage superposition unit 109, current detectors 110U, 110V, 110W, a parameter table TB, and an adder A1.

[0020] FIG. 4 is a diagram schematically illustrating an example of the configuration of the flag generation unit illustrated in FIG. The flag generating unit 108 includes a rotation determining unit 8A and a generating unit 8B. The rotation discriminator 8A generates a stop discrimination flag for discriminating whether the electric motor is stopped. The rotation discriminator 8A calculates an estimated value θ of the rotation phase angle calculated based on the detected values ​​of the three-phase AC currents (iu, iv, iw). e _FBK is used to determine whether the synchronous machine M is rotating or stopped (stop state of the synchronous machine M). The rotation determination unit 8A sets a stop determination flag to 1 when the synchronous machine M is stopped, and outputs the stop determination flag as zero when the synchronous machine M is rotating.

[0021] FIG. 5 is a diagram schematically showing a configuration example of the rotation determination unit shown in FIG. 4. The rotation determination unit 8A includes a position change amount calculation unit 8AA, an absolute value calculation unit 8AB, and a comparison unit 8AC. The position change amount calculation unit 8AA obtains the estimated value θ e _FBK of the rotation phase angle of the synchronous machine M, and calculates and outputs the difference between the current value and the previous value of the estimated value θ e _FBK. The absolute value calculation unit 8AB calculates and outputs the absolute value of the output value of the position change amount calculation unit 8AA.

[0022] The comparison unit 8AC compares the output value (A) of the absolute value calculation unit 8AB with the threshold value (B), and when A < B, sets the stop determination flag to 1 (stop), and when A ≥ B, sets the stop determination flag to zero (rotation) and outputs it.

[0023] The generation unit 8B generates a plurality of flags used for control during the motor parameter tuning operation when the calculation completion flag is zero (the calculation is not completed) (when the synchronous machine M stops and the DC current applied to the synchronous machine M is less than the threshold value). In the present embodiment, the generation unit 8B generates an operation mode flag, a calculation execution flag, a d / q axis calculation flag, a save / use flag, and an initial position estimation flag.

[0024] The operation mode flag is supplied to the voltage command generation unit 102, the high-frequency voltage superposition unit 109, and the rotation angle / speed calculation unit 106, and is used to switch between the parameter tuning (motor parameter calculation) operation and the normal operation. The calculation execution flag is supplied to the parameter calculation unit 107 and is used to manage the execution of the motor parameter calculation.

[0025] The d / q axis calculation flag is supplied to the parameter calculation unit 107 and the parameter table TB, and is used to control whether to calculate the parameters related to either the d axis or the q axis. The save / use flag is supplied to the parameter table TB and is used to switch between saving and using the data in the created parameter table TB. The initial position estimation flag is supplied to the high frequency voltage superimposing unit 109 and is used to determine the period for estimating the stop position of the rotor 20 of the synchronous machine M.

[0026] FIG. 6 is a diagram schematically illustrating an example of a flag generated by the generating unit. When the synchronous machine M is stopped and the DC current applied to the synchronous machine M is less than the threshold value (when the calculation completion flag is zero), the generation unit 8B sets the operation mode flag to zero (motor parameter tuning operation) and sets the inverter control device 100 to the parameter calculation mode. When the calculation completion flag becomes 1, the generation unit 8B sets the operation mode flag to 1 (normal operation) and sets the inverter control device 100 to the normal operation mode.

[0027] The generation unit 8B generates an initial position estimation flag that periodically rises (changes from zero to one) during the period when the operation mode flag is zero (motor parameter tuning operation). The generation unit 8B raises the calculation execution flag when the initial position estimation flag first changes from 1 to 0. The generation unit 8B sets the calculation execution flag to 0 a predetermined time after setting it to 1, and then raises the calculation execution flag when the initial position estimation flag first changes from 1 to 0.

[0028] The generation unit 8B sets the save / use flag in response to the calculation execution flag changing from 1 to 0. The generation unit 8B switches the value of the d / q axis calculation flag at the timing when the save / use flag changes from 1 to 0.

[0029] The current command generator 101 generates a torque command T dref Based on the d-axis current command I d_ref and q-axis current command I q_ref The current command generator 101 generates a torque command T dref current amplitude command Idq * and the current amplitude command I dq * and current phase command β * Therefore, the d-axis current command I is calculated as shown in the following equations (3) and (4). d_ref and q-axis current command I q_ref Calculate.

[0030]

number

[0031] The voltage command generating unit 102 includes a parameter calculation function unit 2A and a normal operation function unit 2B, and switches the function (mode) to be operated depending on the value of the operation mode flag and the value of the stop determination flag.

[0032] FIG. 7 is a block diagram schematically showing an example of the configuration of the parameter calculation function unit of the voltage command generation unit. When the operation mode flag is zero and the stop discrimination flag is one, the parameter calculation function unit 2A of the voltage command generation unit 102 calculates the d-axis voltage command V dc_p and the q-axis voltage command V qc_p The parameter calculation function unit 2A has output switching units 2AA and 2AB.

[0033] The output switching unit 2AA selects the d-axis voltage command V d_ref The output value (d-axis voltage command V dc_p When the d / q axis calculation flag is zero, the output switching unit 2AA switches the output value to the d axis voltage command V d_ref When the d / q axis calculation flag is 1, the output value is set to zero.

[0034] The output switching unit 2AB switches the q-axis voltage command V q_refThe output value (q-axis voltage command V qc_p The output switching unit 2AB switches the output value to zero when the d / q axis calculation flag is zero, and switches the output value to the q axis voltage command V q_ref The value is

[0035] Voltage command V used in parameter calculation function unit 2A d_ref , V q_ref The maximum value of the voltage command V is determined using the rated current of the synchronous machine M and the motor winding resistance R. d_ref , V q_ref The quotient obtained by dividing this value by the value of the motor winding resistance R is the current value that flows through the synchronous machine M, so the maximum value of the voltage that can be applied to the synchronous machine M can be determined so that the current that flows does not exceed the rated current.

[0036] The voltage command calculated by the parameter calculation function unit 2A may be generated so that a predetermined switching element is kept on in a switching pattern that applies a voltage of a predetermined conduction phase (d-axis or q-axis). In this case, if the DC voltage applied to the inverter main circuit INV is high, the current may increase immediately, which may cause element failure. To avoid this, it is desirable to PWM-modulate the voltage command and apply it to the inverter INV to control the average voltage value.

[0037] FIG. 8 is a block diagram schematically showing an example of the configuration of the normal operation function unit of the voltage command generation unit. When the operation mode flag is 1, the normal operation function unit 2B of the voltage command generation unit 102 sets a voltage command value that matches the current command and the current detection value by performing PI control based on the current deviation. The normal operation function unit 2B has subtraction units 2BA and 2BD, PI control units 2BB and 2BE, addition units 2BC and 2BF, and an FF voltage calculation unit 2BG.

[0038] The FF voltage calculation unit 2BG calculates the d-axis current command I d_ref and the q-axis current command I q_refThe values ​​of the angular velocity, the d-axis inductance Ld for the fundamental current, and the q-axis inductance Lq for the fundamental current are obtained, and the feedforward voltage command V is calculated as shown in equation (11) below. d_FF (=ω e _FBK×I q_ref ×Lq), V q_FF (=ω e _FBK×I d_ref × Ld).

[0039] The subtractor 2BA calculates the d-axis current command I d_ref and the d-axis current I in the estimated rotating coordinate system dc The difference between d_ref -I dc ) is calculated and output. The PI control unit 2BB obtains the output value of the subtraction unit 2BA and calculates the d-axis current command I d_ref and the d-axis current I in the estimated rotating coordinate system dc PI control is performed so that the difference between dc Calculate.

[0040] The adder 2BC calculates the d-axis voltage command V dc and the d-axis feedforward voltage command V d_FF The values ​​of and are obtained, and the sum of the obtained values ​​is calculated and output. The subtractor 2BD calculates the q-axis current command I q_ref and the q-axis current I in the estimated rotating coordinate system dc The difference between q_ref -I qc ) is calculated and output.

[0041] The PI control unit 2BE obtains the output value of the subtraction unit 2BD and calculates the q-axis current command I q_ref and the q-axis current I in the estimated rotating coordinate system qc PI control is performed so that the difference between qc Calculate. The adder 2BF calculates the q-axis voltage command V qc and the q-axis feedforward voltage command V q_FFThe values ​​of and are obtained, and the sum of the obtained values ​​is calculated and output.

[0042] The voltage command generating unit 102 converts the output value of the adding unit 2BC into a d-axis voltage command V dc_p The output value of the adder 2BF is the q-axis voltage command V qc_p Output as In addition, when the operation mode flag is zero and the stop discrimination flag is 1, the parameter calculation function unit 2A of the voltage command generation unit 102 operates, and when the operation mode flag is 1, the normal operation function unit 2B operates, and when the operation mode flag is zero and the stop discrimination flag is zero (from the start of parameter tuning until the motor stops), the parameter calculation function unit 2A and the normal operation function unit 2B of the voltage command generation unit 102 are stopped.

[0043] FIG. 9 is a diagram schematically illustrating an example of the configuration of the high-frequency voltage superimposing unit shown in FIG. The high frequency voltage superimposing unit 109 generates a high frequency voltage of an arbitrary frequency corresponding to a triangular wave carrier (carrier command) for the d axis or the q axis or both, depending on the values ​​of the operation mode flag, the low speed / high speed flag, and the initial position estimation flag, and outputs the generated high frequency voltage to the adder A1. In this embodiment, the high frequency voltage superimposing unit 109 generates a high frequency voltage V h Output.

[0044] The high frequency voltage superimposing unit 109 includes switches 9A, 9B, and 9C, a synchronization pulse generating unit 9D, and a high frequency voltage synchronization unit (logical AND operation unit) 9E. The switch 9A outputs a voltage command V h The switch 9A obtains the value of the voltage command V when the low speed / high speed flag is set to zero (low speed). h When the low speed / high speed flag is 1 (high speed), it outputs zero.

[0045] The switch 9B outputs a voltage command V hWhen the initial position estimation flag is 1, the switch 9B acquires the value of the voltage command V h When the initial position estimation flag is zero, it outputs zero.

[0046] Switch 9C acquires the output value of switch 9A and the output value of switch 9B and switches the output value according to the value of the operation mode flag. Switch 9C outputs the output value of switch 9A when the operation mode flag is 1 (normal operation), and outputs the output value of switch 9B when the operation mode flag is zero (motor parameter tuning operation).

[0047] The synchronization pulse generator 9D generates a synchronization pulse synchronized with the triangular wave carrier and outputs it to the high frequency voltage synchronization unit 9E. The high frequency voltage synchronization unit 9E multiplies the output value of the switch 9C by the synchronization pulse and outputs the result.

[0048] The high frequency voltage superimposing unit 109 outputs the output value of the high frequency voltage synchronizing unit 9E to the adder A1. That is, when the operation mode flag is 1 and the low speed / high speed flag is 0, and when the operation mode flag is 0 and the initial position estimation flag is 1, the output value of the high frequency voltage superimposing unit 109 is a predetermined amplitude V h and the high frequency voltage period (1 / f h ) with high frequency voltage command V h The high frequency voltage superimposing unit 109 outputs zero when the operation mode flag is 1 and the low speed / high speed flag is 1, and when the operation mode flag is zero and the initial position estimation flag is zero.

[0049] The high-frequency voltage command value V output from the high-frequency voltage superimposing unit 109 h is added to adder A1 to obtain the d-axis voltage command V dc_p The output value of adder A1 is added to the d-axis voltage command value V dc to the coordinate (dq / 3Φ) conversion unit 103. In this embodiment, the high-frequency voltage command value V h is the q-axis voltage command V qc_pis not added to the q-axis voltage command V qc_p is the q-axis voltage command V qc are supplied to the coordinate (dq / 3Φ) conversion unit 103 and the parameter calculation unit 107 as

[0050] The coordinate (dq / 3Φ) conversion unit 103 converts the supplied voltage command value V dc_p , V qc_p Using the estimated value of the rotation angle, the vector value Vu * , Vv * , Vw * and outputs it to the modulation section 104.

[0051] The modulation unit 104 modulates the three-phase voltage command value Vu * , Vv * , Vw * into a gate command for the inverter main circuit INV. In this embodiment, the modulation unit 104 converts a triangular wave carrier and a voltage command value Vu * , Vv * , Vw * A gate command is generated by PWM modulation that compares the voltage and the voltage, and the gate command is output to the inverter main circuit INV.

[0052] The current detectors 110U, 110V, and 110W detect two or three phases of AC current (iu, iv, and iw) of the three-phase AC current flowing through the synchronous machine. When detecting two of the three phases of AC current, the value of the remaining phase of AC current can be calculated using the detected values ​​of the two phases of AC current.

[0053] The coordinate (3Φ / dq) conversion unit 105 converts the estimated value θ of the rotation angle e Using _FBK, the detected values ​​of current detectors 110U, 110V, and 110W are estimated from the values ​​in the three-phase fixed coordinate system. The d-axis current I dc and q-axis current I qc and convert it to the value.

[0054] The rotation angle / speed calculation unit 106 calculates the rotation angle θ e _FBK and rotational angular velocity ω e_FBK. Furthermore, the rotation angle / speed calculation unit 106 generates and outputs the value of the low speed / high speed flag according to the rotation speed of the synchronous machine M during normal operation.

[0055] When the operation mode flag is zero (motor parameter tuning operation), the rotation angle / speed calculation unit 106 applies a DC voltage to the synchronous machine M to calculate the motor parameters by calculating the angular speed ω e Fix _FBK to zero and angle θ e _FBK is also fixed. In this case, the fixing angle θ e _FBK is, for example, the value of the initial position estimation result. When tuning the motor parameters, the angular velocity ω e _FBK and angle θ e By setting _FBK as described above, it is possible to apply a DC voltage after determining the position of the rotor 20 of the synchronous machine M.

[0056] FIG. 10 is a diagram schematically illustrating an example of the configuration of the rotation angle / speed calculation unit shown in FIG. The rotation angle / speed calculation unit 106 includes a rotation speed estimation unit 6A, a set value comparison unit 6B, an integration unit 6C, an initial position estimation unit 6D, and switches 6E and 6F.

[0057] The rotation speed estimation unit 6A operates when the operation mode flag is 1 (normal operation), and obtains the current value I from the table TB. dc , I dc For example, the inductances Ld, Lq and the d-axis current I dc , q-axis current I dc , voltage command V dc , V qc , high frequency voltage command V h Using these values, the estimated rotational angular velocity ω e Calculate _EST.

[0058] When the operation mode flag is 1, the rotation speed estimation unit 6A calculates the angular velocity estimated value ω e _EST is calculated and integrated to obtain the angle estimate θ eDepending on the value of the low-speed / high-speed flag, the rotation speed estimation unit 6A can use, for example, a method of observing high-frequency current in the low-speed rotation region of the synchronous machine M, and a method of observing induced voltage in the high-speed rotation region of the synchronous machine M.

[0059] For example, in SynRM, when the rotational phase angle error Dq is zero (when the actual dq axes and the estimated dcqc axes coincide), the voltage equation is expressed by the following equation (5).

[0060]

number

[0061] Estimated rotation phase angle θ e _EST is the true rotation phase angle θ e In contrast to the voltage equation (5) when the estimated rotation phase angle and the true rotation phase angle do not match, the dq-axis voltage equation can be rewritten as the following equation (6) using the rotation angle error Δθ.

number

[0062] where:

number

[0063] When the low speed / high speed flag is zero (low speed), the rotation speed estimation unit 6A can observe the high frequency current supplied to the synchronous machine M and calculate an estimated value of the rotation angular speed as follows. For example, the high frequency voltage command V superimposed on the voltage commandh In response to this, a high frequency current is generated in the output current of the inverter main circuit INV. The rotation angle / speed calculation unit 106 calculates the amplitude of the detected high frequency current and the high frequency voltage command V h Using the above formula, it is possible to calculate an estimated value of the rotor position of the synchronous machine M in the low speed range and the rotational angular velocity corresponding to the initial position. Note that the high frequency voltage command V generated by the high frequency voltage superimposing unit 109 in the rotation angle / speed calculation unit 106 is h The rotation angle / speed calculation unit 106 calculates the value of the high frequency voltage command V output from the high frequency voltage superimposing unit 109. h may be obtained.

[0064] Equation (6) can be summarized in terms of the current differential terms to give equation (7).

number

[0065]

number

[0066] Furthermore, the high-frequency voltage command V h If the voltage command is applied only to the dc axis, which is the estimated axis of the d axis, then the high frequency voltage command v qh is zero and the d-axis high-frequency voltage command v dh The above equation (8) can be rewritten as equation (9).

number

[0067] According to the above equation (9), it can be seen that the qc-axis harmonic current changes depending on the rotation angle error Δθ. Therefore, if we focus on the qc-axis component of the harmonic current, the rotation phase angle error Δθ can be expressed as the following equation (10).

number

[0068] As described above, the rotational speed estimation unit 6A utilizes the characteristic that the qc-axis component of the harmonic current depends on the rotational movement angle error Δθ, calculates the rotational phase angle error Δθ using equation (10), and performs PLL (Phase Locked Loop) control so that the rotational phase angle error Δθ converges to zero, thereby estimating the rotational speed estimate ω e _EST can be calculated.

[0069] Furthermore, the rotation speed estimation unit 6A observes both the dc-axis component and the qc-axis component of the harmonic current to calculate an estimated value ω of the rotation speed. e For example, the qc-axis current i qc The DC axial current I dc Divide by the amplitude of the high frequency current to I dch , I qch Then, the rotational phase angle error Δθ is expressed by the following equation (10)′.

[0070]

number

[0071] FIG. 11 is a diagram schematically illustrating an example of the configuration of a harmonic current detection unit of the rotation speed estimation unit shown in FIG. FIG. 12 is a diagram illustrating an example of the operation of the band-pass filter. 13 and 14 are diagrams for explaining an example of the operation of the FFT analysis unit.

[0072] The harmonic current detection unit includes a bandpass filter 6AA and an FFT analysis unit 6AB. The bandpass filter 6AA receives the response current value (output current) I dc receives the high-frequency voltage command V h Frequency (superimposed high frequency voltage frequency) f h A band f containing frequencies equal to dh The high frequency current component I dc Extract and output ´.

[0073] The FFT analysis unit 6AB calculates, for example, the high-frequency current component I dc ´ is analyzed by FFT (Fast Fourier Transform) to find the high frequency current amplitude I dch The FFT analysis unit 6AB detects, for example, the high frequency current component I dc ´ and high frequency voltage command V h and the high-frequency current component I dc The value of ´ is sampled, and the high frequency current amplitude I dch may be detected.

[0074] The harmonic current detector also detects the high-frequency current amplitude I qch can be detected. The rotational speed estimation unit 6A calculates the rotational phase angle error Δθ from the above equation (10)' using the high-frequency current amplitude detected by the harmonic current detection unit, and performs PLL control so that the rotational phase angle error Δθ converges to zero, thereby estimating the rotational angular speed ω e _EST can be calculated.

[0075] It is also possible to calculate an estimated value of the initial position of the rotor of the synchronous machine M by using the above-mentioned method for calculating an estimated value of the angular velocity in the low speed range.

[0076] When the low speed / high speed flag is 1 (high speed), the rotation speed estimation unit 6A calculates an estimated value ω of the rotation angular speed by using a method of observing the induced voltage of the synchronous machine M. e Specifically, for example, when the SynRM is rotating at high speed, the estimated value of the rotational angular velocity ω can be calculated based on the relationship between the output of the current controller and the feedforward voltage.e The following method for calculating _EST can be adopted.

[0077] The voltage equation when an error Δθ occurs in the rotational phase angle is equation (6), and in this case, the feedforward voltage command is equation (11).

number

[0078] The output of the current control (PI control) corresponds to the difference between equations (6) and (11), and is therefore given by equation (12) below.

number

[0079] If there is no error in the motor parameter settings or rotation phase angle, the value of equation (12) will be zero for both the dc-axis component and the qc-axis component. Focusing on the d-axis component, we obtain equation (13).

number

[0080] When the axis error is sufficiently small, equation (13) can be modified to equation (14).

number

[0081] The estimated value ω of the rotational angular velocity calculated by the rotational velocity estimation unit 6A e_EST is supplied to the rotation speed estimation unit 6A, and also to the switch 6E, the set value comparison unit 6B, and the integration unit 6C.

[0082] The set value comparison unit 6B operates when the operation mode flag is 1 (normal operation) and compares the estimated value ω of the rotational angular velocity output from the rotational velocity estimation unit 6A. e The set value comparison unit 6B compares the estimated value ω_EST with a preset threshold value to generate and output a low-speed / high-speed flag value indicating whether the synchronous machine M is in the low-speed range or the high-speed range. e When _EST is equal to or less than the threshold, the value of the low speed / high speed flag is set to zero (low speed), and the estimated value of the rotation angular velocity ω e When _EST is greater than the threshold, the value of the low speed / high speed flag is output as 1 (high speed).

[0083] The integrator 6C integrates the estimated rotational angular velocity ω calculated by the rotational velocity estimator 6A. e Integrate _EST to get the estimated rotation angle θ e The rotation angle estimated value θ calculated by the integration unit 6C is output. e _EST is supplied to the rotation speed estimation unit 6A and the switch 6F.

[0084] The initial position estimation unit 6D calculates and outputs an estimate of the initial position of the rotor 20 of the synchronous machine M according to the value of the initial position estimation flag. The initial position estimation unit 6D can calculate the estimate of the initial position, for example, by a method similar to the method for calculating the estimate of the rotation angle of the synchronous machine M in the low speed range.

[0085] The switch 6E is a switch for switching the estimated rotational angular velocity ω e The switch 6E acquires the value of the operation mode flag and switches the output value according to the value of the operation mode flag. The switch 6E outputs zero when the value of the operation mode flag is zero (parameter tuning operation), and outputs the estimated value ω of the rotation angular velocity calculated by the rotation speed estimator 6A when the value of the operation mode flag is 1 (normal operation). e Output _EST.

[0086] The switch 6F is connected to the synchronous machine M and the rotor 20. ... e The switch 6F outputs the estimated initial position of the rotor 20 of the synchronous machine M when the value of the operation mode flag is zero (parameter tuning operation), and outputs the estimated value θ of the rotation angle calculated by the integrator 6C when the value of the operation mode flag is 1 (normal operation). e Output _EST.

[0087] Although the rotation angle / speed calculation unit 106 described above uses a method of observing the d-axis voltage as an example, it is also possible to adopt a method of observing the d-axis and q-axis voltages. Furthermore, in this example, the estimated values ​​of the rotation angle and rotation angular velocity are calculated using a method that focuses on high-frequency voltage and high-frequency current in the low-speed range, and a method that focuses on induced voltage in the high-speed range. The method of calculating the estimated values ​​of the rotation angle and rotation angular velocity is not limited to the above, and it is also possible to apply, for example, a method that uses an extended induced voltage, which is a known technique.

[0088] Additionally, although the example explained here is sensorless control that does not use angle or speed sensors, it is also possible to use speed sensors such as PG (pulse generator) or angle sensors such as resolvers. Note that when a PG is used, the absolute position of the rotor is unknown, so it is necessary to estimate the initial position of the rotor, but when a resolver is used, it is also possible to omit the superposition of a short-time high-frequency signal for initial position estimation.

[0089] The parameter table TB includes tables that store the current-inductance relationship for each of the d-axis current and the q-axis current. The parameter table TB determines whether to store data in the d-axis or q-axis table depending on the value of the d / q-axis calculation flag, and switches between storing (updating) and using data depending on the value of the save / use flag. Therefore, data updates are not performed while the motor parameter data stored in the parameter table TB is being used.

[0090] The parameter calculation unit 107 uses the current values ​​generated when a DC voltage is applied to the d-axis and q-axis of the synchronous machine M to calculate inductances Ld and Lq corresponding to the current values. The parameter calculation unit 107 calculates the inductances Ld and Lq, which are motor parameters, according to the values ​​of the calculation execution flag and the d / q axis calculation flag. An example of a method for calculating the inductances Ld and Lq will be described below.

[0091] As described above, the voltage equation of the SynRM can be expressed by the following equation (5).

number

[0092] At the timing when the inductances Ld and Lq are calculated, the rotation speed of the synchronous machine M is zero, so if ω=0, then equation (5) becomes equation (15) below.

number

[0093] Current i in Eq. (15) d , i q By multiplying and transforming the equation, we obtain the following equation (16).

number

[0094] Here, the inductances Ld and Lq and the current i d , i q The product of this is the magnetic flux φ d , φ q Therefore, the following equation (17) is used.

number

[0095] From equations (16) and (17), the relationship between voltage and magnetic flux can be expressed as equation (18) below.

number

[0096] Equation (18) can be summarized in terms of the magnetic flux of the d-axis and q-axis to obtain equation (19) below.

number

[0097] Integrating both sides of equation (19) gives the magnetic flux φ between the d-axis and q-axis. d , φ q can be expressed by equations (20) and (21), respectively.

number

[0098] Substituting equations (20) and (21) into the magnetic flux term of equation (17) gives the following equations (22) and (23).

number

[0099] Furthermore, both sides of equations (22) and (23) are expressed as current i d , i q By dividing by this, the inductances Ld and Lq can be calculated as shown in the following equations (24) and (25).

number

[0100] When the above equations (24) and (25) are calculated by a microcomputer, dt is set in control calculation cycle increments. The parameter calculation unit 107 is configured to calculate the inductances Ld and Lq in accordance with the above equations (24) and (25).

[0101] FIG. 15 is a diagram schematically illustrating an example of the configuration of the parameter calculation unit shown in FIG. The parameter calculation unit 107 calculates a calculation execution flag, a d / q axis calculation flag, a stop determination flag, and a voltage command V dc , V qc and the current I in the estimated rotating coordinate system dc , I qc and calculates the motor parameters when the calculation execution flag is 1 and the stop determination flag is 1 (stop). In this embodiment, the parameter calculation unit 107 calculates inductances Ld and Lq as the motor parameters.

[0102] The parameter calculation unit 107 includes switches 7A and 7B, a subtraction unit 7C, an integration unit 7D, a division unit 7E, a table 7F, a resistance value multiplication unit 7G, a lower limiter 7H, and a sampler 7I.

[0103] The switch 7A is connected to the voltage command V dc , V qc and switches the output value according to the value of the d / q axis calculation flag. When the d / q axis calculation flag is zero, the switch 7A switches the output value according to the value of the dc axis voltage command V dc When the d / q axis calculation flag is 1, the voltage command V qc Output the value of .

[0104] The switch 7B is connected to the current I dc , I qc and switches the output value according to the value of the d / q axis calculation flag. When the d / q axis calculation flag is zero, the switch 7B switches the output value according to the value of the dc axis current I dc When the d / q axis calculation flag is 1, the qc axis current I qc Output the value of .

[0105] The resistance value multiplication unit 7G calculates the product of the output value I_FBK of the switch 7B multiplied by the value of the motor winding resistance R, and supplies the calculation result to the subtraction unit 7C. The subtraction unit 7C calculates the difference obtained by subtracting the output value of the resistance value multiplication unit 7G from the output value V of the switch 7A, and supplies the calculation result to the integration unit 7D.

[0106] The integrator 7D integrates the output value (VR×I_FBK) of the subtractor 7C to calculate the magnetic flux Φ corresponding to the above-mentioned equations (20) and (21), and supplies the magnetic flux Φ to the divider 7E. Lower limiter 7H sets a lower limit (>zero) for the output value of switch 7B, and when a value I_FBK equal to or greater than the lower limit is input, outputs the input value I_FBK as the current value I, and when a value I_FBK less than the lower limit is input, outputs the lower limit value as the current value I. As a result, output value I of lower limiter 7H becomes a value greater than zero, making it possible to avoid division by zero in divider 7E.

[0107] The division unit 7E calculates the quotient by dividing the magnetic flux Φ output from the integration unit 7D by the current value I output from the lower limiter 7H, and supplies the inductance value L corresponding to the above-mentioned equations (24) and (25) to the table 7F.

[0108] The sampler 7I outputs a sampling signal corresponding to the timing at which the table 7F stores the inductance value L, in accordance with the output value (current value) I_FBK of the switch 7B. In this embodiment, the sampler 7I sets, for example, a maximum setting value for the current value I_FBK, and outputs a sampling signal so that the inductance value L is stored in the table 7F every time the output value I_FBK increases by 10%, with the maximum setting value being 100%. The maximum setting value for the current value I_FBK is, for example, the rated value of the current output from the inverter main circuit INV. The sampling signal may include information indicating the degree of achievement of the output value I_FBK (10%, 20%, ... 100%).

[0109] The sampler 7I outputs the calculation completion flag as zero until the current value I_FBK reaches the maximum set value, and then changes the calculation completion flag from zero to 1 when the current value I_FBK reaches the maximum set value. When the current value I_FBK reaches the maximum set value and the calculation completion flag changes from zero to 1, the parameter calculation by the parameter calculation unit 107 is completed.

[0110] Table 7F stores the relationship between the current value I_FBK and the inductance value L according to the sampling signal. Once the storage of the inductance value L corresponding to the current value I_FBK 100% is completed, table 7F outputs table data of the inductance value L corresponding to the current value I_FBK 10%-100%.

[0111] Next, an example of the operation of performing parameter tuning in the inverter control device and synchronous machine driving device of this embodiment will be described. FIG. 16 is a flowchart illustrating an example of the operation of the inverter control device and the synchronous machine driving device of the first embodiment.

[0112] When performing parameter tuning, flag generation unit 108 changes the operation mode flag from 1 to 0 and starts generating a flag for performing parameter tuning. Flag generation unit 108 may periodically perform parameter tuning by changing the operation mode flag from 1 to 0, or may perform parameter tuning by changing the operation mode flag from 1 to 0 in response to a command from a higher-level control device or the like.

[0113] When the operation mode flag changes from 1 to 0, the inverter control device 100 switches from normal operation to parameter tuning operation. When parameter tuning starts, the flag generation unit 108 periodically sets the initial position estimation flag.

[0114] While the initial position estimation flag is set, the high frequency voltage command V h is output, and the high frequency voltage command V h is the d-axis voltage command V dc_p is superimposed on The rotation angle / speed calculation unit 106 calculates the rotation phase angle error Δθ using, for example, the above-mentioned equation (10) or equation (10)′, and performs PLL control so that the rotation phase angle error Δθ converges to zero, thereby obtaining the estimated value ω of the rotation angular speed. e _FBK and rotation phase angle estimate θ e _FBK is calculated to perform initial position estimation (step SA1).

[0115] Next, the rotation discriminator 8A calculates the estimated value θ of the rotation phase angle calculated by the rotation angle / speed calculator 106. e Obtain _FBK and estimate the rotation phase angle θ e The latest value of _FBK is compared with the previous value (step SA2), and the value of a stoppage determination flag indicating whether or not the rotor of the synchronous machine M is stopped is generated and output.

[0116] At this time, the rotation discriminator 8A calculates the estimated value θ of the rotation phase angle. e When the difference between the latest value and the previous value of _FBK is equal to or greater than a predetermined threshold, it is determined that the rotor 20 of the synchronous machine M is rotating (step SA3, No), and steps SA1-SA3 are repeated while maintaining the stop determination flag at zero until the difference between the latest value and the previous value becomes less than the predetermined threshold.

[0117] The rotation discriminator 8A estimates the rotation phase angle θ e When the difference between the latest value and the previous value of _FBK is less than a predetermined threshold value, it is determined that the rotor of the synchronous machine M is stopped (step SA3, Yes), and the stop determination flag is set to 1 (stopped). When the stop determination flag changes from zero to one, parameter tuning is performed (step SA4).

[0118] FIG. 17 is a flowchart illustrating an example of a parameter tuning operation in the inverter control device and the synchronous machine driving device of the first embodiment. FIG. 18 is a diagram illustrating an example of table data generated by the parameter calculation unit shown in FIG.

[0119] The voltage command generating unit 102 determines whether to apply a DC voltage to the d-axis or the q-axis of the synchronous machine M according to the value of the d / q-axis calculation flag, and generates a voltage command V dc , V qc is output (step SB1).

[0120] In this case, the voltage applied to the synchronous machine M can be determined taking into consideration the final value of the current that flows. The relationship between the maximum setting value (final value) of the current that flows through the synchronous machine M during parameter tuning and the applied voltage is expressed by the following equations (26) and (27).

number

[0121] The voltage command generating unit 102 generates a voltage command when the current flowing through the synchronous machine M reaches a maximum set value I d_max , I q_max The voltage v applied to the synchronous machine M is equal to or greater than d , v q (Voltage command V dc , V qc For example, if the rated current value of the synchronous machine M is known in advance, the desired maximum setting value I d_max , I q_max Alternatively, the rated current value of the motor M may be set to the maximum setting value (100%).

[0122] The coordinate (dq / 3Φ) conversion unit 103 converts the voltage command value V dc , V qc Using the estimated value of the rotation angle, the vector value Vu * , Vv * , Vw * and outputs it to the modulation section 104.

[0123] The modulation unit 104 modulates the three-phase voltage command value Vu * , Vv * , Vw * The inverter main circuit INV generates a gate command using the above and outputs the gate command to the inverter main circuit INV. The inverter INV performs switching in response to the gate command, and applies a DC voltage to one of the d-axis and q-axis of the synchronous machine M (step SB2).

[0124] Fig. 18 shows an example of the current generated when a DC voltage is applied to one of the d-axis and q-axis of the synchronous machine M, and the calculation results of the inductance value. According to the example in Fig. 18, when a DC voltage is applied to the synchronous machine M, the current increases nonlinearly. The parameter calculation unit 107 converts the current value I calculated by the coordinate (3Φ / dq) conversion unit 105 into dc , I qc is acquired and the current value is detected (step SB3), for example, the current value I dc , I qc The calculated values ​​of inductances Ld and Lq are sampled every time the value increases by 10% (step SB4).

[0125] The parameter calculation unit 107 performs steps SB2-SB4 until the current value reaches the maximum set value (100%), and when the current value reaches the maximum set value, it sets the calculation completion flag to 1 and completes the parameter calculation.

[0126] When the calculation completion flag changes from zero to one, the flag generation unit 108 sets the calculation execution flag to zero, sets the save / use flag, and saves in table TB the table data output from the parameter calculation unit 107. If the timing for tuning the motor parameters is set in advance, the parameter calculation unit 107 may reset the calculation completion flag to zero in accordance with that timing, or, for example, when a command to tune the motor parameters is received from a higher-level controller, the calculation completion flag may be set to zero in response to that command.

[0127] Next, the flag generation unit 108 changes the value of the d / q axis calculation flag and sets the calculation execution flag, and after confirming that the rotor 20 of the synchronous machine M has stopped, as in steps SA1-SA4 above, causes the parameter calculation unit 107 to start calculating motor parameters for the current-carrying phase (either the d axis or the q axis) for which new motor parameters have not yet been calculated.

[0128] When the calculation completion flag is 1 and calculation of the motor parameters for both the d-axis and q-axis is completed, the flag generation unit 108 determines whether calculation of the parameters has been completed under all conditions (step SA5). For example, the conditions for calculating the motor parameters may be set in advance in the flag generation unit 108.

[0129] If there are conditions for which the motor parameters have not yet been calculated (step SA5, No), the flag generation unit 108 performs the above-mentioned steps SA1-SA4 for each calculation condition to calculate the motor parameters for each of the d-axis and q-axis and update the table TB.

[0130] If the motor parameter calculation has been completed under all conditions (Yes in step SA5), the flag generation unit 108 sets the calculation execution flag to zero, raises the save / use flag, and stores the table data output from the parameter calculation unit 107 in the table TB. After that, the flag generation unit 108 resets the d / q-axis calculation flag after the table TB has been updated, and after a predetermined period of time, raises (sets) the operation mode flag (to 1), ends parameter tuning, and starts normal operation of the inverter control device 100.

[0131] As described above, the inverter control device and synchronous machine drive device of this embodiment can calculate the inductances Ld and Lq, which are motor parameters, by applying a DC voltage to the d-axis or q-axis and observing the d-axis or q-axis current that is generated during this application. Furthermore, the inverter control device and synchronous machine drive device of this embodiment can complete acquisition of the motor parameters in a relatively short time when the synchronous machine time constant (τ = L / R) is small. In this embodiment, a high-frequency voltage command is superimposed on a voltage command when estimating the initial position of the rotor 20 of the synchronous machine M. However, it is only necessary to superimpose the high-frequency voltage command for the short time required for initial position estimation, thereby avoiding long-term noise and vibration.

[0132] That is, according to this embodiment, it is possible to provide an inverter control device and a synchronous machine driving device that suppress a decrease in reliability and comfort.

[0133] In the parameter tuning operation described above, the inverter control device and synchronous machine drive device are described as calculating the motor parameters only once under the same calculation conditions. However, the accuracy of the motor parameters can be further improved by repeating the same sequence several times under the same calculation conditions to calculate the average value of multiple parameters, or by performing post-processing such as omitting outliers.

[0134] In the above embodiment, the explanation of providing a dead time in the gate command of the inverter main circuit INV to prevent element short-circuiting in the inverter main circuit INV has been omitted. In reality, the gate command of the inverter main circuit INV is provided with a dead time, and the actual value of the output voltage of the inverter main circuit INV deviates from the command value by the dead time. Therefore, it is desirable to correct the deviation between the command value and the actual value (dead time compensation). For example, a method of correcting the gate command according to the polarity of the phase current may be used. Alternatively, a method of obtaining the PWM voltage directly or indirectly (for example, by performing voltage / frequency conversion) using a voltage sensor and correcting the voltage command value through feedback control may be used. Dead time compensation can improve the accuracy of motor parameter calculation.

[0135] Furthermore, in the above embodiment, a method for calculating motor parameters (inductances Ld, Lq) using each quantity in the dq rotating coordinate system has been described, but the same effect can be obtained by calculating motor parameters using voltage commands and current detection values ​​converted from values ​​in the dq rotating coordinate system to values ​​in the three-phase fixed coordinate system.

[0136] Next, a description will be given of modified examples of the inverter control device and synchronous machine drive device of the first embodiment. In the following description of the modified examples and embodiments, the same components as those in the first embodiment will be denoted by the same reference numerals and will not be described again.

[0137] FIG. 19 is a diagram for explaining a first modified example of table data generated by the parameter calculation unit shown in FIG. In the above-described first embodiment, an example has been described in which the voltage command generating unit 102 increases the DC voltage command in a stepwise manner. In the first modified example, the voltage command generating unit 102 generates a DC voltage command that rises gradually.

[0138] For example, when the DC voltage command increases stepwise, the output current of the inverter main circuit INV may suddenly jump up, resulting in a decrease in the accuracy of the current detection value. When the accuracy of the current detection value decreases, it becomes difficult to accurately determine the timing for sampling the motor parameters. Therefore, in the first modification, the DC voltage command is gradually increased to suppress the transient response of the output current of the inverter main circuit INV, which suddenly jumps up. This allows the parameter calculation unit 107 to accurately obtain the timing for sampling the motor parameters, thereby reducing parameter calculation errors.

[0139] FIG. 20 is a diagram for explaining a second modified example of the table data generated by the parameter calculation unit shown in FIG. In the first embodiment described above, the voltage command generating unit 102 generates a DC voltage command so as to apply a constant DC voltage to the synchronous machine M. When a constant DC voltage is applied to the synchronous machine M, the current increases according to the time constant, and therefore the larger the current, the more frequently the sampling timing of the motor parameters becomes. When driving a synchronous machine M in which the current changes quickly, there is a possibility that the parameter calculating unit 107 may miss the calculation results of the motor parameters.

[0140] Therefore, in the second modification, the voltage command generation unit 102 adjusts the DC voltage command value according to the current level, for example, so that the amount of change in the output current of the inverter main circuit INV is approximately constant. By controlling the voltage according to the magnitude of the current, the sampling intervals of the motor parameters can be equalized in real time, and the parameter calculation unit 107 can accurately sample the calculation results of the motor parameters. Furthermore, according to the second comparative example, it is possible to suppress abrupt rotation of the synchronous machine M caused by a sudden increase in the output current of the inverter main circuit INV.

[0141] The voltage command generating unit 102 may generate a DC voltage command by combining the first and second modifications described above. In either case, the same effects as those of the inverter control device and synchronous machine driving device of the first embodiment described above can be obtained.

[0142] Next, an inverter control device and a synchronous machine driving device according to a second embodiment will be described in detail with reference to the drawings. FIG. 21 is a block diagram schematically showing an example of the configuration of an inverter control device and a synchronous machine driving device according to the second embodiment.

[0143] In the first embodiment described above, it was confirmed that the rotation of the synchronous machine M had stopped by estimating the initial position of the rotor 20 of the synchronous machine M, but in this embodiment, a DC voltage is applied to the q-axis of the synchronous machine M, which has a high inductance, to pull in the rotor 20, thereby causing a sufficient amount of current to flow into the synchronous machine M, generating torque equivalent to the current and stopping the rotation of the synchronous machine M, and then tuning the motor parameters. In this embodiment, initial position estimation is not performed during parameter tuning, and therefore the value of the initial position estimation flag is zero during the period in which parameter tuning is being performed.

[0144] The inverter control device 100 of this embodiment differs from the first embodiment in the configurations of the voltage command generating unit 102 and the flag generating unit 108.

[0145] FIG. 22 is a diagram schematically illustrating an example of a flag generated by the flag generating unit illustrated in FIG. In this embodiment, since initial position estimation is not performed in the parameter calculation mode, the initial position estimation flag is omitted in FIG.

[0146] After the operation mode flag is zero and the stop determination flag becomes zero, the flag generation unit 108 changes the calculation execution flag from zero to 1, and causes the parameter calculation unit 107 to perform parameter tuning.

[0147] FIG. 23 is a block diagram schematically showing an example of the configuration of the rotation determination unit of the flag generation unit shown in FIG. The rotation determination unit 8A determines the stopped state by changing the current (d-axis current, q-axis current) to be observed depending on whether the d-axis or q-axis motor parameters are being calculated. The stop determination flag is set to 1 when it is determined that the synchronous machine M is stopped, and to 0 when it is determined that the synchronous machine M is rotating.

[0148] When a DC voltage is applied to the q-axis, the U-phase current is ideally zero. However, as the rotor 20 rotates, the U-phase current increases or decreases from zero. In this embodiment, the rotation determination unit 8A detects this change in the U-phase current to determine the rotation of the rotor 20. Furthermore, when a DC voltage is applied to the d-axis, ideally only the U-phase current flows, and no current flows in the V-phase or W-phase. Therefore, the rotation determination unit 8A observes the difference between the V-phase and W-phase current values ​​and zero to determine the rotation of the rotor 20.

[0149] The rotation determination unit 8A includes absolute value calculation units 8AD-8AF, a subtraction unit 8AG, comparison units 8AH and 8AI, and a switching unit 8AJ. The absolute value calculation unit 8AD acquires the detected value iu of the U-phase output current of the inverter main circuit INV, calculates the absolute value of the detected value iu, and outputs it.

[0150] The absolute value calculation unit 8AE acquires the detected value iv of the V-phase output current of the inverter main circuit INV, calculates the absolute value of the detected value iv, and outputs it. The absolute value calculation unit 8AF acquires the detected value iw of the W-phase output current of the inverter main circuit INV, calculates the absolute value of the detected value iw, and outputs it.

[0151] The subtraction section 8AG calculates and outputs the difference obtained by subtracting the output value of the absolute value calculation section 8AE from the output value of the absolute value calculation section 8AD. The comparison unit 8AH sets the output value of the subtraction unit 8AG as the discrimination index A, and outputs the result of comparing the discrimination index A with the threshold value B. The comparison unit 8AH outputs zero (rotation) when the discrimination index A is greater than the threshold value B, and outputs 1 (stop) when the discrimination index A is equal to or less than the threshold value B.

[0152] The comparison unit 8AI sets the output value of the absolute value calculation unit 8AF as the discrimination index A, and outputs the result of comparing the discrimination index A with the threshold value B. Note that the threshold value B in the comparison unit 8AH and the threshold value B in the comparison unit 8AI may be different values ​​or may be the same values. The comparison unit 8AI outputs zero (rotation) when the discrimination index A is greater than the threshold value B, and outputs 1 (stop) when the discrimination index A is equal to or less than the threshold value B.

[0153] The switching unit 8AJ switches the output value of the rotation discrimination unit 8A according to the value of the d / q-axis calculation flag. When the value of the d / q-axis calculation flag is zero (d-axis), the switching unit 8AJ outputs the output value of the comparison unit 8AH as the value of the stop discrimination flag, and when the value of the d / q-axis calculation flag is 1 (q-axis), the switching unit 8AJ outputs the output value of the comparison unit 8AI as the value of the stop discrimination flag.

[0154] In addition, the rotation discrimination unit 8A may reset the value of the stop discrimination flag to zero at the timing when the value of the d / q axis calculation flag is switched, and then output a value according to the value of the d / q axis calculation flag.

[0155] FIG. 24 is a block diagram schematically showing an example of the configuration of the voltage command generating unit shown in FIG. 24 shows functional blocks of the voltage command generating unit 102 that operates in the parameter calculation mode. The functional blocks of the voltage command generating unit 102 that performs normal operation are the same as those in the first embodiment described above.

[0156] In this embodiment, the voltage command generating unit 102 includes at least a normal operation function unit 2B and a rotation stop command generating unit 2C. Rotation stop command generator 2C operates when the value of the operation mode flag is zero. When the value of the stop discrimination flag is zero, rotation stop command generator 2C performs current control only for one of the energized phases of the d-axis and q-axis, and sets the value of the DC voltage command for the other energized phase to zero. In the example shown in FIG. 24, when the value of the stop discrimination flag is zero, rotation stop command generator 2C performs current control only for the q-axis, and sets the value of the DC voltage command for the d-axis to zero.

[0157] The rotation stop command generating unit 2C includes subtraction units 2CAd and 2CAq, PI control units 2CBd and 2CBq, and a switch 2CC. The subtractor 2CAd calculates the d-axis current command I d_ref and the q-axis current I in the estimated rotating coordinate system dc The difference between d_ref -I dc ) is calculated and output. The subtractor 2CAq calculates the q-axis current command I q_ref and the q-axis current I in the estimated rotating coordinate system qc The difference between q_ref -I qc ) is calculated and output.

[0158] The PI control unit 2CBd obtains the output value of the subtraction unit 2CAd and calculates the d-axis current command I d_ref and the d-axis current I in the estimated rotating coordinate system dc PI control is performed so that the difference between dc_p is calculated and output to the switch 2CC. The PI control unit 2CBq obtains the output value of the subtraction unit 2CAq and calculates the q-axis current command I q_ref and the q-axis current I in the estimated rotating coordinate system qc PI control is performed so that the difference between qc_p Calculate and output. Furthermore, when the operation mode flag is zero and the stop determination flag is zero, the switch 2CC switches the d-axis voltage command V dc_p When the operation mode flag is zero and the stop determination flag is 1, the output value of the PI control unit 2CBd is set to the d-axis voltage command V dc_p The value is output as The voltage command V output from the rotation stop command generating unit 2C dc_p , V qc_p The value of is input to the coordinate (dq / 3Φ) conversion unit 103.

[0159] By generating the voltage command as described above, in this embodiment, the rotor 20 can be fixed at an intended angle by retracting it, rather than measuring the position at which the rotor 20 stops. In the above example, when the stop determination flag is zero, current control is performed only on the q-axis, and the value of the DC voltage command for the d-axis is set to zero. By using the voltage command value generated in this manner, a DC voltage is applied to the q-axis, which has the highest inductance (easily generates magnetic flux), to generate magnetic flux targeting the q-axis, thereby enabling the rotational position to be retracted.

[0160] When the synchronous machine M is a SynRM, the energization phase that is most likely to generate magnetic flux is the q-axis, and when the synchronous machine M is another type of synchronous machine, the energization phase that is most likely to generate magnetic flux is basically the d-axis.

[0161] FIG. 25 is a block diagram schematically showing an example of the configuration of the rotation angle / speed calculation unit shown in FIG. In this embodiment, the output value of the switch 6F in the rotation angle / speed calculation unit 106 is different from that in the first embodiment.

[0162] The switch 6F switches between zero and the estimated rotation angle θ e The switch 6F obtains the value of _EST and switches the output value depending on the value of the operation mode flag. The switch 6F outputs zero when the value of the operation mode flag is zero (parameter tuning operation), and outputs the estimated value θ of the rotation angle calculated by the integrator 6C when the value of the operation mode flag is 1 (normal operation). eThis is because the synchronous machine M is stopped at the intended axis (θ=90°), so the d-axis of the synchronous machine M and the U-phase winding are facing each other. In this case, the rotation phase angle θ e _FBK is fixed to zero.

[0163] FIG. 26 is a flowchart illustrating an example of the operation of the inverter control device and the synchronous machine driving device of the second embodiment. When the operation mode flag becomes zero, parameter tuning is started. When parameter tuning is started, the value of the stop determination flag is zero (rotation). When the values ​​of the operation mode flag and the stop determination flag are zero, the voltage command generation unit 102 generates a voltage command to fix the rotor 20 of the synchronous machine M at an intended angle by retracting it. The inverter main circuit INV is controlled using the voltage command to stop the rotation output from the voltage command generation unit 102, and the rotor 20 of the synchronous machine M is stopped (step SC1).

[0164] Next, the rotation determination unit 8A of the flag generation unit 108 outputs the value of a stop determination flag indicating whether the rotor 20 of the synchronous machine M is stopped or not, depending on the value of the d / q axis calculation flag and the values ​​of the output current values ​​iu, iv, and iw of the inverter main circuit INV.

[0165] When the stop determination flag changes from zero (rotating) to 1 (stopped) (Yes in step SC2), parameter tuning is executed (step SC3). The parameter tuning operation is the same as in the first embodiment described above.

[0166] Next, the flag generation unit 108 changes the value of the d / q axis calculation flag and sets the calculation execution flag, and after confirming that the rotor 20 of the synchronous machine M has stopped, as in steps SC2-SC3 above, causes the parameter calculation unit 107 to start calculating motor parameters for the current-carrying phase (either the d axis or the q axis) for which new motor parameters have not yet been calculated.

[0167] When the calculation completion flag is 1 and calculation of the motor parameters for both the d-axis and q-axis has been completed, the flag generation unit 108 determines whether calculation of the parameters has been completed under all conditions (step SC4). For example, the conditions for calculating the motor parameters may be set in the flag generation unit 108 in advance.

[0168] If there are conditions for which the motor parameters have not yet been calculated (step SC4, No), the flag generation unit 108 performs the above-mentioned steps SC2-SC3 for each calculation condition to calculate the motor parameters for each of the d-axis and q-axis and update the table TB.

[0169] If the calculation of motor parameters has been completed under all conditions (step SC4, Yes), the flag generation unit 108 sets the calculation execution flag to zero, raises the save / use flag, and saves the table data output from the parameter calculation unit 107 in the table TB. Thereafter, the flag generation unit 108 resets the d / q-axis calculation flag after the table TB has been updated, and after a predetermined period of time, raises (sets) the operation mode flag (to 1), ends parameter tuning, and starts normal operation of the inverter control device 100.

[0170] As described above, the inverter control device and synchronous machine drive device of this embodiment can calculate the inductances Ld and Lq, which are motor parameters, by applying a DC voltage to the d-axis or q-axis and observing the d-axis or q-axis current that occurs during this process. Furthermore, with the inverter control device and synchronous machine drive device of this embodiment, if the synchronous machine time constant (τ=L / R) is small, the motor parameters can be obtained in a relatively short time.

[0171] Furthermore, according to the inverter control device and synchronous machine drive device of this embodiment, the rotor 20 can be actively stopped when the rotation of the synchronous machine M is not stopped, and the d-axis or q-axis inductance characteristics can be obtained more accurately. That is, in this embodiment, by retracting and stopping the rotor 20, the rotor 20 can be stopped at the intended stopping point each time, and the motor parameters can be calculated. This improves the accuracy of the calculation of the motor parameters. Furthermore, even if the rotor 20 has rotated, the rotor 20 can be immediately stopped at the intended angle, and the motor parameters can be calculated.

[0172] That is, according to this embodiment, it is possible to provide an inverter control device and a synchronous machine driving device that suppress a decrease in reliability and comfort.

[0173] In this embodiment, after parameter calculation unit 107 has completed calculation of all motor parameters and stored the motor parameters in table TB, initial position estimation may be performed when transitioning to normal operation. This improves the accuracy of calculation of the estimated value of the rotational phase angle, and enables the rotation of synchronous machine M to be smoothly accelerated after transitioning to normal operation.

[0174] Next, a modification of the inverter control device and synchronous machine driving device of the second embodiment will be described. In the first and second embodiments described above, the parameter calculation unit 107 calculates the d / q-axis inductances Ld and Lq as motor parameters, but in this comparative example, an example will be described in which the parameter calculation unit 107 further calculates the motor winding resistance of the synchronous machine M.

[0175] In the inverter control device of this comparative example, the parameter calculation unit 107 includes a resistance calculation unit 7J. In this comparative example, parameter calculation unit 107 acquires the value of the operation mode flag, and when the operation mode flag becomes zero (motor parameter tuning operation), resistance calculation unit 7J calculates the resistance value R. The value of motor winding resistance R calculated by resistance calculation unit 7J is used in resistance value multiplication unit 7G of parameter calculation unit 107 shown in FIG.

[0176] The resistance calculation unit 7J calculates the angular velocity θ and the d-axis current I d _FBK and q-axis current I q _FBK and q-axis current command I q_ref and get the value of . In this specification, the d-axis current I d _FBK and q-axis current I q _FBK is the d-axis current I in the dcqc estimated coordinate system. dc and q-axis current I qc The d-axis current I in the dcqc estimated coordinate system can be treated as the same value. dc and q-axis current I qc are the d-axis current and q-axis current observed on the estimated coordinate (θe_FBK) calculated without using angle sensors or speed sensors. The d-axis current I d _FBK and q-axis current I q _FBK is the d-axis current I observed on the estimated coordinate system. dc and q-axis current I qc and the feedback value including the d-axis current and the q-axis current observed on the coordinates obtained using the sensor. In this specification, even for values ​​other than the d-axis current and the q-axis current, the subscript c is added to the symbol for values ​​observed on the estimated coordinates, and the feedback value including values ​​observed on the estimated coordinates and values ​​observed on the coordinates using the sensor is added to the symbol "_FBK."

[0177] In the second embodiment, when the motor parameter tuning operation is started, the rotor 20 of the synchronous machine M is stopped by the pull-in, so the angular velocity θ becomes zero. At this time, the q-axis current I q _FBK command I q_ref If the values ​​are calculated correctly, the relationship between voltage and current is given by equation (28).

[0178]

number

[0179] Both sides of the above equation (28) are expressed as the q-axis current command I q_ref Dividing this by the value, the motor winding resistance R is given by the following equation (29).

number

[0180] FIG. 27 is a diagram schematically showing a configuration of a resistance calculation unit of the parameter calculation unit shown in FIG. The resistance calculation section 7J includes a lower limiter 7JF, a division section 7JG, and a low-pass filter 7JH. The lower limiter 7JF limits the q-axis current I q The _FBK value is compared with the threshold value to determine the q-axis current I q When the _FBK value is below the threshold, the threshold is output and the q-axis current I q When the FBK value is greater than the threshold, the q-axis current I q The _FBK value is output. Since the current flowing to the synchronous machine M is small immediately after the start of current flow, a lower limiter 7JF is provided to prevent division by zero, which prevents the denominator value from becoming zero.

[0181] The divider 7JG calculates the quotient (V q / I q _FBK). Low-pass filter 7JH outputs a value obtained by removing frequency components above a predetermined threshold from the output value of divider 7JG, thereby reducing the influence of ripples caused by PWM control that are included in the output value of divider 7JG. The resistance calculation unit 7J outputs the output value of the low-pass filter 7JH as the value of the motor winding resistance R.

[0182] FIG. 28 is a flowchart illustrating an example of the operation of the inverter control device and the synchronous machine driving device according to the modified example of the second embodiment. When the operation mode flag becomes zero (motor parameter tuning operation), parameter tuning starts. When parameter tuning starts, the value of the stop discrimination flag is zero (rotation). When the values ​​of the operation mode flag and the stop discrimination flag are zero, the voltage command generation unit 102 generates a voltage command to retract the rotor 20 of the synchronous machine M and fix it at an intended angle. The inverter main circuit INV is controlled using the voltage command to stop the rotation output from the voltage command generation unit 102, and the rotor 20 of the synchronous machine M is stopped (step SD1).

[0183] Next, the rotation determination unit 8A of the flag generation unit 108 determines whether the rotor 20 of the synchronous machine M is stopped or not according to the value of the d / q axis calculation flag and the values ​​of the output current values ​​iu, iv, and iw of the inverter main circuit INV (step SD2), and outputs the value of the stop determination flag indicating the determination result (1: stopped, zero: rotating).

[0184] While the flag generating unit 108 makes the stop determination, the parameter calculating unit 107 calculates the value of the motor winding resistance R (step SD3). When the stop determination flag changes from zero (rotating) to 1 (stopped) (step SD2, Yes), parameter tuning is executed (step SD4). The parameter tuning operation is the same as that in the first embodiment. At this time, the parameter calculation unit 107 calculates the inductances Ld and Lq using the value of the motor winding resistance R calculated by the resistance calculation unit 7J according to the value of the d / q-axis calculation flag.

[0185] FIG. 29 is a diagram showing an example of timing for latching the motor winding resistance value in the parameter calculation unit of the inverter control device according to the modified example of the second embodiment. In this figure, the effect is explained without taking into consideration the dead time of the gate command of the switching element, but by performing dead time compensation, it is possible to improve the accuracy of the motor winding resistance calculation results.

[0186] When parameter tuning begins, the current command value gradually increases up to a predetermined value. The voltage command value increases as long as the rate of change of the current command value is large, and when the current command value converges to the predetermined value, the voltage command value also converges to the predetermined value. The value of the motor winding resistance R is proportional to the voltage command value and inversely proportional to the current command value, reaches a peak while the current command value and voltage command value are changing, and then changes to converge to the predetermined value.

[0187] In this modified example, the parameter calculation unit 107 latches the value of the motor winding resistance R when the change in the value of the motor winding resistance R becomes smaller than a threshold value and converges to a predetermined value, and uses the latched value to calculate the inductances Ld and Lq.

[0188] Next, the flag generation unit 108 changes the value of the d / q axis calculation flag and sets the calculation execution flag, and after confirming that the rotor 20 of the synchronous machine M has stopped, as in steps SC2-SC3 above, causes the parameter calculation unit 107 to start calculating motor parameters for the current-carrying phase (either the d axis or the q axis) for which new motor parameters have not yet been calculated.

[0189] When the calculation completion flag is 1 and calculation of the motor parameters for both the d-axis and q-axis has been completed, the flag generation unit 108 determines whether calculation of parameters has been completed under all conditions (step SD5). For example, the conditions for calculating the motor parameters may be set in the flag generation unit 108 in advance.

[0190] If there are conditions for which the motor parameters have not yet been calculated (step SD54, No), the flag generation unit 108 performs the above-mentioned steps SD2-SD4 for each calculation condition to calculate the motor parameters for each of the d-axis and q-axis and update the table TB.

[0191] If the motor parameter calculation has been completed under all conditions (step SD5, Yes), the flag generation unit 108 sets the calculation execution flag to zero, raises the save / use flag, and stores the table data output from the parameter calculation unit 107 in the table TB. Thereafter, the flag generation unit 108 resets the d / q-axis calculation flag after the table TB has been updated, and after a predetermined period of time, raises (sets) the operation mode flag (to 1), ends parameter tuning, and starts normal operation of the inverter control device 100.

[0192] As described above, in this modification, the voltage command generating unit 102 pulls in and stops rotor 20 of synchronous machine M, and the flag generating unit 108 confirms that rotor 20 has stopped, and at the same time, the parameter calculating unit 107 calculates the value of motor winding resistance R. That is, after calculating the value of motor winding resistance R, the parameter calculating unit 107 can proceed to parameter tuning using the calculated value of motor winding resistance R. This allows the parameter calculating unit 107 to detect the winding resistance value, which changes depending on temperature, as a value closer to the actual value, thereby improving the accuracy of the parameter calculation.

[0193] That is, the inverter control device and synchronous machine drive device of this modified example make it possible to measure the value of the motor winding resistance R of the synchronous machine M without using a measuring device such as a tester. In particular, the winding resistance value of the synchronous machine M is temperature dependent and changes depending on the usage environment and conditions, so by calculating the motor winding resistance value as in this modified example, it is possible to calculate the motor winding resistance value under conditions closer to those during actual operation, and the accuracy of the inductance calculation itself, which is performed using the calculation results, can be improved.

[0194] In the second embodiment and its modified example described above, a method of applying a DC voltage to the q-axis where inductance is maximum when stopping the pull of the synchronous machine M has been adopted, but it is also possible to adopt a method of applying a DC voltage to the d-axis to pull the synchronous machine M. In this case, the variables in the calculations used when using the method of pulling the q-axis can be reinterpreted as those for the d-axis and applied.

[0195] Next, an inverter control device and a synchronous machine driving device according to a third embodiment will be described in detail with reference to the drawings. This embodiment differs from the first and second embodiments in that the inverter control device 100 applies a DC voltage to both the d-axis and q-axis of the synchronous machine M to tune the motor parameters. When searching for an operating point at which the synchronous machine M outputs maximum torque with minimum current, it is desirable to stop the rotor 20 by an external force because torque is generated. In the following description, it is assumed that the rotor 20 of the synchronous machine M can be fixed by an external force such as a brake or a mechanical mechanism.

[0196] FIG. 30 is a block diagram schematically showing a configuration example of an inverter control device and a synchronous machine driving device according to the third embodiment. In the inverter control device 100, the parameter calculation unit 107 inputs a current level command to the voltage command generation unit 102 in order to control the current flowing through the synchronous machine M. Note that in the first and second embodiments described above, the current level was not controlled because a DC voltage was applied to the synchronous machine M, causing the current to increase nonlinearly. The value of the current level command for determining the current amplitude is determined in the parameter calculation unit 107 by comparing the maximum setting value (final value) of the current flowing through the synchronous machine M with the values ​​of the d-axis current and the q-axis current during parameter tuning. The current level command is sufficient to include a value indicating the result of comparing at least the maximum setting value of the current with the d-axis current value and the q-axis current value, and may be a value indicating the ratio of the flowing current to the maximum setting value (for example, a value between 0% and 100% inclusive, depending on the resolution of the inductance table to be created, such as 10%, 20%, 30%, ... 100%).

[0197] In this embodiment, after starting tuning of the motor parameters, the voltage command generating unit 102 determines the value of the current (current command) to be applied to the synchronous machine M, and calculates the voltage value (voltage command) according to the determined current value.

[0198] If we consider that the synchronous machine M becomes almost a resistive load on the motor windings when it is stopped, the relationship between the current flowing through the synchronous machine M and the voltage is given by the following equation (30).

number

[0199] Furthermore, if the lead angle of the vector based on the d-axis is β, the current and voltage for the motor winding resistance load are given by the following equation (31).

number

[0200] When obtaining inductance according to a certain operating point of the synchronous machine M, if the current operating point for which you want to create an inductance table is already determined, you can specify the lead angle β according to the current operating point. If the current operating point is not yet determined, you can specify the vector lead angle β and voltage amplitude v dq Adjustments are necessary.

[0201] In this embodiment, the synchronous machine M is assumed to be under MTPA (Maximum Torque Per Ampere) control so that maximum torque output is obtained at minimum current during normal operation. The voltage command generating unit 102 determines whether or not the torque calculation value (torque Trq calculated by the following equation (32)) has increased before and after changing the calculation conditions for the motor parameters, and adjusts the phase of the voltage command (= vector lead angle β), for example, so that an inductance table is created at an operating point where maximum torque is output at minimum current.

[0202] The voltage command generating unit 102 can calculate the inductance according to the current flowing through the synchronous machine M. Furthermore, the voltage command generating unit 102 can calculate the torque Trq as shown in the following equation (32) using the values ​​of the d-axis current and the q-axis current.

[0203]

number

[0204] The voltage command generator 102 stores and compares the torque Trq calculated by the above equation (32) before and after the change in the calculation conditions for the motor parameters. If the torque Trq exceeds the value based on the previous phase command, the voltage command generator 102 advances the phase advance angle β.

[0205] If the torque Trq decreases from the previous value (value based on the previous phase command), this indicates that the maximum torque point has been exceeded, and the voltage command generating unit 102 stores the motor parameters in a table, using the previous value of the current command as the operating point.

[0206] If the current level is smaller than the specified value, the parameter calculation unit 107 adjusts the current level command to increase the value of the voltage command generated by the voltage command generation unit 102, and executes the above sequence again to create a table of motor parameters.

[0207] FIG. 31 is a block diagram schematically showing an example of the configuration of the voltage command generating unit shown in FIG. The voltage command generation unit 102 includes a current command calculation unit 2DA, a voltage command calculation unit 2DB, a torque increase determination unit 2DC, and a phase command unit 2DD. The current command calculation unit 2DA, the voltage command calculation unit 2DB, the torque increase determination unit 2DC, and the phase command unit 2DD operate when the operation mode flag is zero (parameter tuning operation) and the stop determination flag is 1 (stop).

[0208] The current command calculation unit 2DA calculates the current level command and the d-axis current I dc value and the estimated q-axis current I qc value and the dq axis current amplitude I dqThe current level command may include, for example, a result of comparing the maximum set value of the current with the d-axis current value and the q-axis current value, or a value indicating the ratio of the energizing current to the maximum set value (for example, 10%, 20%, 30%, ... 100%). The current command calculation unit 2DA calculates and outputs the d-axis current I dc and q-axis current I qc Using the values ​​of and , the dq axis current amplitude I dq Furthermore, the current command calculation unit 2DA calculates the dq-axis current amplitude I so that it becomes a value for searching for an operating point where the synchronous machine M has the maximum torque / minimum current under other conditions (for example, current increase) according to the value of the current level command. dq may be calculated.

[0209] The torque increase determination unit 2DC determines the d-axis current I dc value and the estimated q-axis current I qc The torque Trq is calculated from the value of the torque Trq and the values ​​of the inductances Ld and Lq using the above equation (32), and a value indicating the result of determining whether the value of the torque Trq has increased from the previous value is output.

[0210] If the torque Trq exceeds the previous value based on the output value of the torque increase determination unit 2DC, the phase command unit 2DD outputs a phase command to advance the phase advance angle β. If the torque Trq decreases from the previous value, this indicates that the maximum torque point has been exceeded, and the voltage command generation unit 102 outputs a phase command so that the previous value of the current command becomes the operating point.

[0211] The voltage command calculation unit 2DB calculates the dq-axis current amplitude I dq and the phase command calculated by the phase command unit 2DD, the values ​​of the d-axis voltage command and the q-axis voltage command are calculated by the above-mentioned equations (30) and (31). The voltage command generation unit 102 sets the amplitude of the current to a value determined by the resolution of the inductance table (value of the current level command), fixes the amplitude of the voltage to a value calculated from the current flowing through the synchronous machine and the motor winding resistance R, and changes the phase of the current by changing the voltage phase, thereby making it possible to search for the maximum torque point and the maximum power factor point described later.

[0212] FIG. 32 is a block diagram schematically showing an example of the configuration of the parameter calculation unit shown in FIG. In this embodiment, the parameter calculation unit 107 can simultaneously calculate both the d-axis and q-axis motor parameters (inductances).

[0213] The parameter calculation unit 107 includes subtraction units 7Cd and 7Cq, integration units 7Dd and 7Dq, division units 7Ed and 7Eq, a table 7F, resistance value multiplication units 7Gd and 7Gq, lower limiters 7Hd and 7Hq, a current level command generation unit 7K, and a maximum current comparison unit 7L.

[0214] The resistance value multiplication unit 7Gd multiplies the d-axis current I dc The product is calculated by multiplying the value by the value of the motor winding resistance R, and the calculation result is supplied to a subtraction unit 7Cd. The subtractor 7Cd calculates the d-axis voltage V dc The difference is calculated by subtracting the output value of the resistance value multiplication unit 7Gd from the value, and the calculation result is supplied to the integration unit 7Dd.

[0215] The integrator 7Dd calculates the output value (V dc -R×I dc ) to calculate the value of the magnetic flux Φ corresponding to the above-mentioned equations (20) and (21), and supplies the magnetic flux Φ to the division unit 7Ed. The lower limiter 7Hd is the d-axis current I dc Set a lower limit (>0) for the value, and then select values ​​greater than or equal to the lower limit. dc If is entered, the value I is entered. dc current value I d and the value I is less than the lower limit. dc When the lower limit is entered, the current value I dAs a result, the output value I of the lower limiter 7Hd d becomes a value greater than zero, and division by zero in the division unit 7Ed can be avoided.

[0216] The division unit 7Ed divides the value of the magnetic flux Φ output from the integration unit 7Dd by the current value I output from the lower limiter 7Hd. d The quotient obtained by dividing by is calculated, and the inductance value Ld corresponding to the above equations (24) and (25) is supplied to table 7F. The resistance multiplication unit 7Gq multiplies the q-axis current I qc The product is calculated by multiplying the value by the value of the motor winding resistance R, and the calculation result is supplied to a subtraction unit 7Cq.

[0217] The subtractor 7Cq calculates the q-axis voltage V qc The difference is calculated by subtracting the output value of the resistance value multiplication unit 7Gq from the value, and the calculation result is supplied to the integration unit 7Dq. The integrator 7Dq calculates the output value (V qc -R×I qc ) to calculate the value of the magnetic flux Φ corresponding to the above-mentioned equations (20) and (21), and supply the magnetic flux Φ to a division unit 7Eq.

[0218] The lower limiter 7Hq is the q-axis current I qc Set a lower limit (>0) for the value, and then select values ​​greater than or equal to the lower limit. qc If is entered, the value I is entered. qc current value I q and the value I is less than the lower limit. qc When the lower limit is entered, the current value I q As a result, the output value I of the lower limiter 7Hq q becomes a value greater than zero, and division by zero in the division unit 7Eq can be avoided.

[0219] The division unit 7Eq divides the value of the magnetic flux Φ output from the integration unit 7Dq by the current value I output from the lower limiter 7Hq. q The quotient obtained by dividing by is calculated, and the inductance value Lq corresponding to the above equations (24) and (25) is supplied to table 7F.

[0220] The current level command generator 7K generates the output value I d and the output value I of the lower limiter 7Hq q In response to this, the table 7F outputs a sampling signal corresponding to the timing at which the inductance values ​​Ld and Lq are stored. d , I q is controlled to return to the previous value when it exceeds the maximum torque of the synchronous machine M. Therefore, the current level command generating unit 7K is configured to, for example, d , I q Monitor the current value I d , I q The current level command generating unit 7K may obtain the determination result of the torque increase determining unit 2DC of the voltage command generating unit 102, and output a sampling signal to store the previous values ​​of the inductances Ld and Lq in the table 7F in accordance with the determination result that the torque has increased.

[0221] The current level command generating unit 7K calculates the current value I at the timing when the inductances Ld and Lq are sampled. d , I q The current level command generating unit 7K may compare the current value I with the maximum set value and output a current level command according to the comparison result. d , I q If the current value I is smaller than the maximum set value, the current level command generating unit 7K may generate and output a current level command indicating that the maximum set value has not been reached (or the next current level). d , I q is equal to or greater than the maximum set value, a current level command indicating that the maximum set value has been reached (or that the conditions for parameter calculation should be changed) may be generated and output.

[0222] In addition, the current level command generating unit 7K determines the current value I d , I q The value of is supplied to the maximum current comparison unit 7L. The maximum current comparison unit 7L compares the current value I d, I q is compared with the maximum set value, and the current value I d , I q When the current value I reaches the maximum set value, it is determined whether there is a condition under which the inductances Ld and Lq have not been calculated. When the calculation of the inductances Ld and Lq is completed under all conditions, the calculation completion flag is changed from 0 to 1 and output to the flag generation unit 108 and the parameter table TB. d , I q When the parameter calculation unit 107 reaches the maximum set value and the calculation completion flag changes from zero to one, the parameter calculation by the parameter calculation unit 107 is completed.

[0223] Table 7F shows the relationship between the current value Id and the inductance value Ld and the current value I q - Save the relationship between the inductance value Lq. Table 7F shows the relationship between the current value I d , I q Once the inductance values ​​Ld and Lq corresponding to 100% have been saved, the current value I d , I q Table data of inductance values ​​Ld and Lq corresponding to 10%-100% is output to the parameter table TB.

[0224] The parameter table TB receives table data from the parameter calculation unit 107, and when the calculation completion flag changes from 0 to 1, it updates the values ​​of the motor parameters with the new table data. Note that in this embodiment, the parameter calculation unit 107 supplies table data including the inductances Ld and Lq of both the d-axis and q-axis to the parameter table TB, so it is possible to omit supplying the value of the d / q-axis calculation flag to the parameter table TB.

[0225] Next, an example of the operation of the inverter control device and the synchronous machine driving device of this embodiment will be described. FIG. 33 is a diagram schematically illustrating an example of a flag generated by the flag generating unit illustrated in FIG. FIG. 34 is a flowchart illustrating an example of the operation of the inverter control device and the synchronous machine driving device of the third embodiment.

[0226] When the operation mode flag changes from 1 to 0, the inverter control device 100 switches from normal operation to parameter tuning operation. When parameter tuning starts, the flag generation unit 108 sets the initial position estimation flag.

[0227] While the initial position estimation flag is set, the high frequency voltage command V h is output, and the high frequency voltage command V h is the d-axis voltage command V dc_p is superimposed on The rotation angle / speed calculation unit 106 calculates the rotation phase angle error Δθ using, for example, the above-mentioned equation (10) or equation (10)′, and performs PLL control so that the rotation phase angle error Δθ converges to zero, thereby obtaining the estimated value ω of the rotation angular speed. e _FBK and rotation phase angle estimate θ e _FBK is calculated to perform initial position estimation (step SE1).

[0228] Next, the rotation discriminator 8A calculates the estimated value θ of the rotation phase angle calculated by the rotation angle / speed calculator 106. e Obtain _FBK and estimate the rotation phase angle θ e The latest value of _FBK is compared with the previous value, and the value of a stoppage determination flag indicating whether the rotor of the synchronous machine M is stopped is generated and output.

[0229] At this time, the rotation discriminator 8A calculates the estimated value θ of the rotation phase angle. e When the difference between the latest value and the previous value of _FBK is equal to or greater than a predetermined threshold, it is determined that the rotor 20 of the synchronous machine M is rotating, and steps SA1 to SA3 are repeated while maintaining the stop determination flag at zero until the difference between the latest value and the previous value becomes less than the predetermined threshold.

[0230] The rotation discriminator 8A estimates the rotation phase angle θ e When the difference between the latest value and the previous value of _FBK is less than a predetermined threshold value, it is determined that the rotor of the synchronous machine M is stopped, and the stop determination flag is set to 1 (stopped).

[0231] In this embodiment, since the rotor 20 of the synchronous machine M is stopped by an external force, the rotation determining unit 8A confirms that the synchronous machine M is stopped before performing parameter tuning.

[0232] When the stop determination flag changes from zero to one, parameter tuning is performed (step SE2). When the operation mode flag is set to zero and the stop determination flag is set to one, the current command calculation unit 2DA of the voltage command generation unit 102 calculates the d-axis current I dc and q-axis current I qc The amplitude of the current flowing through the synchronous machine M using dq is calculated (step SE3).

[0233] Next, the voltage command calculation unit 2DB of the voltage command generation unit 102 calculates the current amplitude I dq Using the value of the motor winding resistance R, the voltage amplitude v is calculated using the above equation (30). dq The voltage command generating unit 102 calculates the voltage command V using the phase β acquired from the phase command unit 2DD according to the above-mentioned equation (31). dc_p , V qc_p is calculated and output (step SE5). dc_p , V qc_p A DC voltage is applied to the synchronous machine M.

[0234] The parameter calculation unit 107 calculates the voltage command V dc_p , V qc_p and the current value I dc , I qc The inductances Ld and Lq are calculated using the formula (step SE6).

[0235] While the torque Trq of the synchronous machine M is increasing (step SE7, Yes), the voltage command generation unit 102 advances the phase β to generate the voltage command V dc_p , V qc_p When the torque Trq of the synchronous machine M decreases (step SE7, No), the voltage command generating unit 102 sets the phase β as the previous value and outputs the voltage command V dc_p , V qc_pCalculates and outputs.

[0236] The parameter calculation unit 107 samples the calculated values ​​of inductances Ld and Lq at the timing when torque Trq decreases (the timing when the phase of the current becomes the previous value) and generates table data that stores the sampled values ​​(step SE8).

[0237] The parameter calculation unit 107 determines whether or not the parameter calculation has been completed for all the conditions for calculating the parameters (step SE9). For example, dc , I qc If it has not reached the maximum set value (step SE9, No), it outputs a current level command to the voltage command generation unit 102 to increase the energizing current (increase the current). If the parameter calculation has been completed for all conditions (step SE9, Yes), the parameter calculation unit 107 outputs the table data and changes the calculation completion flag from zero to one, thereby completing the parameter calculation.

[0238] In the third embodiment described above, the inverter control device 100 searches for the maximum torque / minimum current point of the synchronous machine M. This may be configured to observe the power factor. When calculating the power factor, it is necessary to assume the rotation speed. For example, the angular speed ω e_n , d-axis voltage v dn , q-axis voltage v qn , d-axis current i dn , q-axis current i qn Then, the voltage equation of the SynRM can be expressed by the following equation (33).

[0239]

number

[0240]

number

[0241] According to this embodiment, similarly to the first and second embodiments described above, it is possible to provide an inverter control device and a synchronous machine driving device that suppress a decrease in reliability and comfort.

[0242] Furthermore, according to the inverter control device and synchronous machine driving device of the third embodiment, it is possible to tune the motor parameters when using motor parameters (inductance) at any operating point such as an actual operating point. Furthermore, in the inverter control device and synchronous machine driving device of the third embodiment, by passing current through both the d-axis and the q-axis during parameter tuning, it is possible to obtain parameter values ​​that take into account mutual interference between the d-axis and the q-axis, and it is possible to obtain an inductance table with higher accuracy.

[0243] The program according to this embodiment may be transferred in a state where it is stored in an electronic device, or in a state where it is not stored in an electronic device. In the latter case, the program may be transferred via a network, or in a state where it is stored in a storage medium. The storage medium is a non-transitory tangible medium. The storage medium is a computer-readable medium. The storage medium may be in any form, such as a CD-ROM or a memory card, as long as it is capable of storing the program and is computer-readable.

[0244] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0245] M... synchronous machine, 10... stator, 20... rotor, 21... air gap, BR1... peripheral bridge, BR2... center bridge, INV... inverter main circuit, 100... inverter control device, 101... current command generation unit, 102... voltage command generation unit, 2A... parameter calculation function unit, 2AA, 2AB... output switching unit, 2B... operation function unit, 2BA, 2BD... subtraction unit, 2BB, 2BE... PI control unit, 2B, 2BF... addition unit, 2BG... FF voltage calculation unit, 2C... rotation stop command Generation unit, 2CA...subtraction unit, 2CB...PI control unit, 2DA...current command calculation unit, 2DB...voltage command calculation unit, 2DC...torque increase determination unit, 2DD...phase command unit, 103...coordinate (dq / 3Φ) conversion unit, 104...modulation unit, 105...coordinate (3Φ / dq) conversion unit, 106...rotation angle / speed calculation unit, 6A...rotation speed estimation unit, 6AA...band pass filter, 6AB...FFT analysis unit, 6B...set value comparison unit, 6C...integration unit, 6D...initial position estimation unit, 6E, 6F...switching unit, 107...parameter calculation unit, 7A, 7B...switching device, 7C, 7Cd, 7Cq...subtraction unit, 7D, 7Dd, 7Dq...integration unit, 7E, 7Ed, 7Eq...division unit, 7F...table, 7G, 7Gd, 7Gq...resistance value multiplication unit, 7H, 7Hd, 7Hq...lower limiter, 7I...sampler, 7J...resistance calculation unit, 7JA, 7JB...subtraction unit, 7JC, 7JD...PI control unit, 7JE...vector conversion unit, 7JF...lower limiter, 7JG...division unit, 7JH...low-pass filter, 7 K...Current level command generation unit, 7L...Maximum current comparison unit, 108...Flag generation unit, 8A...Rotation discrimination unit, 8AA...Position change amount calculation unit, 8AB...Absolute value calculation unit, 8AC...Comparator, 8AD-8AF...Absolute value calculation unit, 8AG...Subtractor, 8AH, 8AI...Comparator, 8AJ...Switching unit, 8B...Generator, 109...High frequency voltage superposition unit, 9A-9C...Switcher, 9D...Synchronization pulse generation unit, 9E...High frequency voltage synchronization unit, A1...Adder, 110U, 110V, 110W...Current detector

Claims

1. a voltage command generating unit that generates a voltage command to be applied to the synchronous machine; a current detection unit that detects a current flowing from an inverter main circuit driven by a gate command based on the voltage command to the synchronous machine; a flag generation unit that switches between a motor parameter tuning operation and a normal operation operation; a parameter calculation unit that calculates motor parameters using the voltage command value and the detection value of the current detection unit during a motor parameter tuning operation, The voltage command generating unit generates the voltage command for applying a DC voltage to the synchronous machine during a motor parameter tuning operation.

2. The inverter control device according to claim 1 , wherein the voltage command generating unit generates the voltage command for applying the DC voltage with a d-axis or a q-axis of the synchronous machine as a target.

3. 2. The inverter control device according to claim 1, wherein the voltage command generating unit generates the voltage command for supplying a current to a current-carrying phase of the synchronous machine that is most likely to generate magnetic flux, and stops the rotor of the synchronous machine by pulling it to a predetermined angle.

4. the voltage command generation unit generates the voltage command for applying the DC voltage with a d-axis and a q-axis of the synchronous machine as targets; 2. The inverter control device according to claim 1, wherein the amplitude and phase of the voltage command are determined using at least one of the torque and power factor of the synchronous machine as an index.

5. The inverter control device according to claim 1 , wherein the parameter calculation unit continues to calculate the motor parameters until the motor parameters corresponding to a current according to a rated current of the synchronous machine are obtained.

6. 2. The inverter control device according to claim 1, wherein the voltage command generating unit determines a maximum value of the voltage command using a rated current of the synchronous machine and a motor winding resistance value.

7. the flag generation unit determines whether a rotor of the synchronous machine is stopped using a current value supplied to the synchronous machine; 2. The inverter control device according to claim 1, wherein the inverter control device switches to execute calculation of the motor parameters in response to determining that the rotor of the synchronous machine is stopped.

8. the motor parameters include a motor winding resistance value of the synchronous machine; 2. The inverter control device according to claim 1, wherein the motor winding resistance value is a quotient obtained by dividing a value corresponding to a DC voltage applied to the synchronous machine by a value corresponding to a current supplied to the synchronous machine.

9. the motor parameters include an inductance of the synchronous machine; 2. The inverter control device according to claim 1, wherein the parameter calculation unit calculates a magnetic flux value generated by applying a DC voltage to the synchronous machine, and calculates the inductance by dividing the magnetic flux value by a value corresponding to a current supplied to the synchronous machine.

10. An inverter control device according to any one of claims 1 to 9; an inverter main circuit driven by a gate command based on the voltage command.

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