control device

Abstract

To suppress delay of convergence of an estimation angle speed of a motor in a reactivation of a control apparatus of the motor.SOLUTION: A control apparatus 1 is constructed by: an estimation part 8 that estimates an angle speed of a motor M; a current value conversion part 7 that converts a U-phase current value, a V-phase current value, and a W-phase current value into a γ-shaft current value and a δ-shaft current value; a γ-δ current command value output part 11 that outputs a γ-shaft current command value and a δ-shaft current command value; a γ-δ voltage command value calculation part that calculates a γ-shaft voltage command value and a δ-shaft voltage command value; and a voltage command value conversion part that converts the γ-shaft voltage command value and the δ-shaft voltage command value into a U-phase voltage command value, a V-phase voltage command value, and a W-phase voltage command value. The estimation part 8 estimates the angle speed by using an estimation expansion dielectric voltage of which a harmonic wave is reduced by a first filter during the driving of the motor M, and the angle speed is estimated by using the estimation expansion dielectric voltage of which the harmonic wave is reduced by a second filter of which a time constant is smaller than the first filter when a reactivation request of the motor M is received.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a motor control device. [Background technology]

[0002] As a motor control device, there is one that, upon motor restart, estimates the motor rotor position based on the estimated angular velocity of the motor, which is estimated based on the estimated value of the UVW phase extended induced voltage, and uses that position to convert the γδ axis voltage command value to the UVW phase voltage command value. Patent document 1 is a related technology.

[0003] Incidentally, when the motor is restarted, there is a risk that the harmonics included in the expanded induced voltage will increase.

[0004] Therefore, when the motor restarts, it is conceivable to attenuate the harmonics contained in the extended induced voltage using a filter.

[0005] However, the delay in the convergence of the estimated angular velocity due to the filter's time constant may reduce the accuracy of the rotor position estimation. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2015-070704 [Overview of the project] [Problems that the invention aims to solve]

[0007] One aspect of the present invention is to suppress the delay in the convergence of the estimated angular velocity of the motor when the motor control device is restarted. [Means for solving the problem]

[0008] One embodiment of the present invention is a control device that generates U-phase voltage command values, V-phase voltage command values, and W-phase voltage command values ​​for controlling an inverter that drives a motor, and comprises: an estimation unit that estimates an estimated extended induced voltage, which is an estimated value of the extended induced voltage generated in the motor, and estimates the angular velocity of the motor based on the estimated extended induced voltage; a current value conversion unit that converts the U-phase current value flowing in the U-phase, the V-phase current value flowing in the V-phase, and the W-phase current value flowing in the W-phase of the motor into a γ-axis current value and a δ-axis current value; a γ-δ current command value output unit that outputs a γ-axis current command value and a δ-axis current command value; a γ-δ voltage command value calculation unit that calculates a γ-axis voltage command value based on the γ-axis current value and the γ-axis current command value, and calculates a δ-axis voltage command value based on the δ-axis current value and the δ-axis current command value; and a voltage command value conversion unit that converts the γ-axis voltage command value and the δ-axis voltage command value into the U-phase voltage command value, the V-phase voltage command value, and the W-phase voltage command value.

[0009] The estimation unit estimates the angular velocity using the estimated extended induced voltage, from which harmonics have been attenuated by the first filter, while the motor is in operation. When a request to restart the motor is received, the estimation unit estimates the angular velocity using the estimated extended induced voltage, from which harmonics have been attenuated by the second filter, which has a smaller time constant than the first filter.

[0010] This suppresses the delay in the convergence of the estimated angular velocity of the motor when the motor is restarted, thereby reducing the decrease in the accuracy of the motor rotor position estimation and enabling the calculation of the voltage command value. As a result, it is possible to prevent the motor from being unable to restart due to an overcurrent flowing through the motor.

[0011] Furthermore, the first filter may be configured to attenuate harmonics of the estimated extended induced voltage along the γ-δ axis, and the second filter may be configured to attenuate harmonics of the estimated extended induced voltage across three phases.

[0012] Furthermore, the first and second filters may be configured to attenuate the harmonics of the estimated extended induced voltage along the γ-δ axis. [Effects of the Invention]

[0013] According to the present invention, when the motor control device is restarted, the delay in the convergence of the estimated angular velocity of the motor can be suppressed. [Brief explanation of the drawing]

[0014] [Figure 1] This is a diagram showing the control system in the first embodiment. [Figure 2] This is a block diagram corresponding to the estimation unit in the first embodiment. [Figure 3] This figure shows the control system in the second embodiment. [Figure 4] This is a block diagram corresponding to the estimation unit in the second embodiment. [Modes for carrying out the invention]

[0015] The embodiments will be described in detail below based on the drawings.

[0016] <First Embodiment> Figure 1 shows the control system in the first embodiment.

[0017] The control system 1 shown in Figure 1 includes, for example, a motor M mounted on a vehicle such as an electric forklift or a plug-in hybrid vehicle, an inverter 2 that drives the motor M, and a control device 3 that outputs a drive signal to the inverter 2. The motor M is, for example, a surface magnet type synchronous motor or an embedded magnet type synchronous motor.

[0018] The inverter 2 drives the motor M using power supplied from the power supply P, and comprises a capacitor C, switching elements SW1 to SW6 (for example, IGBTs (Insulated Gate Bipolar Transistors)), and current sensors Se1 to Se3. Specifically, one terminal of capacitor C is connected to the positive terminal of the power supply P and the collector terminals of switching elements SW1, SW3, and SW5, while the other terminal of capacitor C is connected to the negative terminal of the power supply P and the emitter terminals of switching elements SW2, SW4, and SW6. The connection point between the emitter terminal of switching element SW1 and the collector terminal of switching element SW2 is connected to the U-phase input terminal of motor M via current sensor Se1. The connection point between the emitter terminal of switching element SW3 and the collector terminal of switching element SW4 is connected to the V-phase input terminal of motor M via current sensor Se2. The connection point between the emitter terminal of switching element SW5 and the collector terminal of switching element SW6 is connected to the W-phase input terminal of motor M via current sensor Se3.

[0019] Capacitor C smooths the voltage output from power supply P and input to inverter 2.

[0020] Switching element SW1 is turned on or off based on the drive signal S1 output from the control device 3. Switching element SW2 is turned on or off based on the drive signal S2 output from the control device 3. Switching element SW3 is turned on or off based on the drive signal S3 output from the control device 3. Switching element SW4 is turned on or off based on the drive signal S4 output from the control device 3. Switching element SW5 is turned on or off based on the drive signal S5 output from the control device 3. Switching element SW6 is turned on or off based on the drive signal S6 output from the control device 3. As switching elements SW1 to SW6 are each turned on or off, the DC voltage output from the power supply P is converted into three AC voltages with a phase difference of 120 degrees from each other, and these AC voltages are applied to the U-phase, V-phase, and W-phase input terminals of the motor M, causing the rotor of the motor M to rotate.

[0021] The current sensor Se1 is composed of a Hall element and a shunt resistor, and measures the U-phase current I flowing through the U-phase of the motor M. u It detects and outputs to the control device 3. The current sensor Se2 is composed of a Hall element and a shunt resistor, and detects the V-phase current value I flowing through the V-phase of the motor M. v It detects and outputs to the control device 3. The current sensor Se3 is composed of a Hall element and a shunt resistor, and detects the W-phase current value I flowing through the W-phase of the motor M. w The system detects this and outputs it to the control device 3. In this embodiment, there are three current sensors Se1 to Se3, but it is also possible to have a configuration with any two of the three instead of three.

[0022] The control device 3 comprises a storage unit 4, a drive circuit 5, and a calculation unit 6. The control device 3 drives the motor M by controlling the inverter 2.

[0023] The memory unit 4 is composed of RAM (Random Access Memory) or ROM (Read Only Memory), etc.

[0024] The drive circuit 5 is composed of an IC (Integrated Circuit) and controls the voltage value of the carrier wave (triangular wave, sawtooth wave, or inverse sawtooth wave, etc.) and the U-phase voltage command value V output from the calculation unit 6. u *, V-phase voltage command value V v *, and W-phase voltage command value V w * is compared with the result, and the drive signals S1 to S6 corresponding to the comparison result are output to the respective gate terminals of the switching elements SW1 to SW6.

[0025] For example, the drive circuit 5 has a U-phase voltage command value V u If * is greater than or equal to the carrier voltage value, a high-level drive signal S1 is output, and a low-level drive signal S2 is output, and the U-phase voltage command value V uWhen * is smaller than the voltage value of the carrier wave, a low-level drive signal S1 is output, and a high-level drive signal S2 is output. Also, the drive circuit 5 outputs a V-phase voltage command value V v When * is equal to or greater than the voltage value of the carrier wave, a high-level drive signal S3 is output, and a low-level drive signal S4 is output, and the V-phase voltage command value V v When * is smaller than the voltage value of the carrier wave, a low-level drive signal S3 is output, and a high-level drive signal S4 is output. Also, the drive circuit 5 outputs a W-phase voltage command value V w When * is equal to or greater than the voltage value of the carrier wave, a high-level drive signal S5 is output, and a low-level drive signal S6 is output, and the W-phase voltage command value V w When * is smaller than the voltage value of the carrier wave, a low-level drive signal S5 is output, and a high-level drive signal S6 is output.

[0026] The arithmetic unit 6 is composed of a microcomputer or the like, and includes a current value conversion unit 7, an estimation unit 8, a subtraction unit 9, a torque command value calculation unit 10, a γ-δ current command value output unit 11, a subtraction unit 12, a subtraction unit 13, a voltage command value calculation unit 14, and a voltage command value conversion unit 15. For example, by executing a program stored in the storage unit 4 by a microcomputer, the current value conversion unit 7, the estimation unit 8, the subtraction unit 9, the torque command value calculation unit 10, the γ-δ current command value output unit 11, the subtraction unit 12, the subtraction unit 13, the voltage command value calculation unit 14, and the voltage command value conversion unit 15 are configured.

[0027] The current value conversion unit 7 uses the estimated position (electrical angle) θ^ of the rotor output from the estimation unit 8 to convert the U-phase current value I u , the V-phase current value I v , and the W-phase current value I w into the γ-axis current value I γ and the δ-axis current value I δ . The current value conversion unit 7 may have a function of inputting two-phase current values among the U-phase current value I u , the V-phase current value I v , and the W-phase current value I w and calculating the remaining one-phase current value from the input two-phase current values.

[0028] The γ-δ coordinate system is an estimated rotating coordinate system in which the axis corresponding to the d-axis of the dq coordinate system is the γ-axis and the axis corresponding to the q-axis is the δ-axis. The dq coordinate system is a rotating coordinate system in which the direction of the north pole of the motor M's magnet is the d-axis and the direction perpendicular to the d-axis is the q-axis. Furthermore, the estimated position θ^ is the estimated value of the position θ of the motor M's rotor.

[0029] For example, the current value conversion unit 7 uses the conversion matrix C1 shown in Equation 1 below to convert the U-phase current value I u V-phase current value I v W-phase current value I w The γ-axis current value I γ and δ-axis current value I δ Convert to.

[0030]

number

[0031] The subtraction unit 9 calculates the angular velocity difference Δω between the estimated angular velocity ω^ output by the estimation unit 8 and the angular velocity command value ω* input from an external source.

[0032] The torque command value calculation unit 10 calculates the torque command value T* using the angular velocity difference Δω output from the subtraction unit 9. For example, the torque command value calculation unit 10 refers to information (not shown) stored in the storage unit 4, which associates the angular velocity of motor M with the torque of motor M, and determines the torque corresponding to the angular velocity corresponding to the angular velocity difference Δω as the torque command value T*.

[0033] The γ-δ current command value output unit 11 uses the torque command value T* to output the γ-axis current command value I γ * and δ-axis current command value I δ * outputs. For example, the γ-δ current command value output unit 11 outputs the torque of the motor M and the γ-axis current command value I stored in the memory unit 4. γ * and δ-axis current command value I δ *Referring to the information (not shown) that is associated with each other, the γ-axis current command value I corresponds to the torque corresponding to the torque command value T*.γ * and δ-axis current command value I δ * is calculated. The γ-δ current command value output unit 11 uses the torque command value T* input from an external source to calculate the γ-axis current command value I γ * and δ-axis current command value I δ The system may be configured to output *. In this configuration, the subtraction unit 9 and the torque command value calculation unit 10 are omitted.

[0034] The subtraction unit 12 subtracts the γ-axis current command value I output from the γ-δ current command value output unit 11. γ * and the γ-axis current value I output from the current value conversion unit 7. γ The difference between the γ-axis current command value and ΔI γ Calculate.

[0035] The subtraction unit 13 subtracts the δ-axis current command value I output from the γ-δ current command value output unit 11. δ * and the δ-axis current value I output from the current value conversion unit 7. δ The difference between the δ axis current command value and ΔI δ Calculate.

[0036] The voltage command value calculation unit 14 calculates the difference γ-axis current command value ΔI output from the subtraction unit 12. γ And the difference δ-axis current command value ΔI output from the subtraction unit 13 δ The γ-axis voltage command value V γ * and δ-axis voltage command value V δ Convert to *. For example, the voltage command value calculation unit 14 calculates the γ-axis voltage command value V by the following equation 2. γ * is calculated, and the δ-axis voltage command value V is calculated by calculating the following equation 3. δ Calculate *. Note that K p Let K be the constant of the proportional term in PI control. i Let be the constant of the integral term in PI control, let ω^ be the estimated angular velocity calculated by the estimation unit 8 for the current control period, and p represent the time derivative operator d / dt. d-axis inductance L d ^ and q-axis inductance L q^ represents an estimated value of the motor parameters of the controlled motor M, which are estimated in advance through measurements using motor M. The reason why the motor parameters of motor M are estimated rather than actual values ​​is that they fluctuate depending on the current flowing through motor M and the temperature. K E This is the induced voltage constant.

[0037] V γ *=K p ΔI γ +∫(K i ΔI γ )-ω^L q ^I γ ...Formula 2 V δ *=KpΔI δ +∫(K i ΔI δ )+ω^L d ^I δ +ω^K E ...Formula 3

[0038] In other words, the subtraction units 12, 13 and the voltage command value calculation unit 14 calculate the γ-axis current value I γ and γ-axis current command value I γ *Based on the gamma-axis voltage command value V γ * Calculate the δ-axis current value I δ and the δ-axis current command value I δ *Based on the δ axis voltage command value V δ It functions as a γ-δ voltage command value calculation unit that calculates *.

[0039] The voltage command value conversion unit 15 uses the estimated position θ^ output from the estimation unit 8 to convert the γ-axis voltage command value V γ * and δ-axis voltage command value V δ * is the U-phase voltage command value V u *, V-phase voltage command value V v * and W-phase voltage command value V w Convert to *. For example, the voltage command value conversion unit 15 uses the conversion matrix C2 shown in equation 4 below to convert the γ-axis voltage command value V γ * and δ-axis voltage command value V δ * is the U-phase voltage command value V u *, V-phase voltage command value V v*, W-phase voltage command value V w * is converted.

[0040]

Number

[0041] The voltage command value conversion unit 15 is the U-phase voltage command value V u *, V-phase voltage command value V v * and W-phase voltage command value V w * is output to the drive circuit 5. That is, the voltage command value conversion unit 15 and the drive circuit 5 can be said to function as a drive signal generation unit that converts the γ-axis voltage command value V γ * and the δ-axis voltage command value V δ * into drive signals and outputs them to the inverter 2.

[0042] The estimation unit 8 has a function of estimating the extended induced voltage and calculating the estimated angular velocity ω^ and the estimated position θ^ based on the estimated extended induced voltage.

[0043] The estimation unit 8 estimates the angular velocity from different extended induced voltages during the driving of the motor M and when a restart request is received.

[0044] FIG. 2 is a block diagram corresponding to the estimation unit 8 in the first embodiment.

[0045] When the estimation unit 8 estimates the angular velocity during the driving of the motor M, the γ-axis current value I γ , δ-axis current value I δ , γ-axis voltage command value V γ *, δ-axis voltage command value V δ *, the estimated angular velocity ω^ stored in the storage unit 4, and the motor parameters of the motor M that can be estimated in advance are used to calculate the estimated extended induced voltage e1^ of the γ-δ axis, and the angular velocity is estimated based on the estimated extended induced voltage e1^ of the γ-δ axis. Specifically, the estimation unit 8, in block 81, inputs the γ-axis current value I γ , δ-axis current value I δ , γ-axis voltage command value V γ * and δ-axis voltage command value V δFrom the following observer (motor model) shown in Formula 5, the estimated extended induced voltage e1^ on the γ-δ axis is calculated. The estimated extended induced voltage e1^ on the γ-δ axis includes the estimated extended induced voltage e γ ^ on the γ axis and the estimated extended induced voltage e δ ^ on the δ axis as vector components.

[0046]

Equation

[0047] Next, the estimation unit 8 attenuates the harmonics included in the estimated extended induced voltage e γ ^ on the γ axis in the first filter 82 to output the corrected estimated extended induced voltage e γ ^', and attenuates the harmonics included in the estimated extended induced voltage e δ ^ on the δ axis to output the corrected estimated extended induced voltage e δ ^'. That is, it can be said that the first filter 82 attenuates the harmonics of the estimated extended induced voltage e1^ on the γ-δ axis. Also, the corrected estimated extended induced voltage e γ ^' and the corrected estimated extended induced voltage e δ ^' are the estimated extended induced voltages with harmonics attenuated by the first filter 82. Note that the first filter 82 is, for example, a low-pass filter using a moving average. Also, the first filter 82 is assumed to have frequency characteristics that attenuate only the harmonics obtained in advance by experiments, simulations, etc.

[0048] Next, the estimation unit 8 calculates the position error Δθ^ by calculating the following Formula 6 from the corrected estimated extended induced voltage e γ ^' and the corrected estimated extended induced voltage e δ ^' in the block 83.

[0049]

Equation

[0050] Then, the estimation unit 8 estimates the angular velocity based on the position error Δθ^. Specifically, for example, in block 84, the position error Δθ^ is multiplied by a predetermined transfer function to estimate the angular velocity ω γδ The ^ symbol is output. In other words, the estimation unit 8 estimates the angular velocity using the estimated extended induced voltage, from which harmonics have been attenuated by the first filter 82.

[0051] On the other hand, when the vehicle's control unit or other device requests a restart of the motor M, the estimation unit 8 calculates the U-phase current value I u V-phase current value I v W-phase current value I w U-phase voltage command value V u *, V-phase voltage command value V v *, W-phase voltage command value V w *, and the motor parameters of motor M are used to calculate the estimated three-phase extended induced voltage e2^, and the angular velocity is estimated based on the estimated three-phase extended induced voltage e2^. Specifically, in block 85, the estimation unit 8 calculates the estimated three-phase extended induced voltage e2^ using the observer (motor model) shown in equation 7 below. The estimated three-phase extended induced voltage e2^ is the U-phase estimated extended induced voltage e u ^, V-phase estimated extended induced voltage e v ^, W-phase estimated extended induced voltage e w The vector contains ^ as a component.

[0052]

number

[0053] The winding resistance R^ is an estimated value of the motor parameters of the motor M being controlled, and is estimated in advance through measurements using the motor M. The reason why it is an estimated value rather than the actual value of the motor parameters of the motor M is that the motor parameters fluctuate depending on the current flowing through the motor M and the temperature.

[0054] Next, the estimation unit 8 determines the U-phase estimated extended induced voltage e in the second filter 86. u Attenuate harmonics contained in ^ to correct U-phase estimated extended induced voltage e uIt outputs ^´ and the V-phase estimated extended induced voltage e v Attenuating harmonics contained in ^ to correct V-phase estimated extended induced voltage e v It outputs ^´ and the W-phase estimated extended induced voltage e w Attenuating harmonics contained in ^ to correct the W-phase estimated extended induced voltage e w It outputs ^'. In other words, the second filter 86 can be said to attenuate the harmonics of the three-phase estimated extended induced voltage e2^. Also, the corrected U-phase estimated extended induced voltage e u ^´, Corrected V-phase estimated extended induced voltage e v ^' and corrected W-phase estimated extended induced voltage e w ^' can be said to be the estimated extended induced voltage after the harmonics have been attenuated by the second filter 86. The second filter 86 is, for example, a low-pass filter using a moving average, and has a smaller time constant than the first filter 82. Furthermore, the second filter 86 is assumed to have a frequency characteristic that attenuates only harmonics, which has been determined in advance through experiments or simulations.

[0055] Then, the estimation unit 8 calculates the estimated angular velocity ω in blocks 87 and 88 by calculating the following equation 8. uvw The ^ symbol is output. In other words, the estimation unit 8 estimates the angular velocity using the estimated extended induced voltage, from which harmonics have been attenuated by the second filter 86.

[0056]

number

[0057] The estimation unit 8 includes a switch 89.

[0058] Switch 89 can be selectively connected to either block 84 or block 88. That is, when switch 89 is connected to block 84, the estimation unit 8 outputs the estimated angular velocity ω from block 84. γδ The ^ is output as the estimated angular velocity ω^, and when switch 89 is connected to block 88, the estimation unit 8 outputs the estimated angular velocity ω from block 88. uvwOutput ^ as the estimated angular velocity ω^.

[0059] To elaborate further, when a request to restart motor M is received, switch 89 is connected to block 88, and after a predetermined time has elapsed since the request to restart motor M was received, or after the estimated angular velocity ω was received uvw When ^ exceeds the threshold, switch 89 is connected to block 84.

[0060] As described above, the estimation unit 8 of this embodiment estimates the angular velocity from different extended induced voltages during motor M operation and when a restart request is received.

[0061] Then, the estimation unit 8 calculates the estimated angular velocity ω γδ ^ or estimated angular velocity ω uvw The estimated position θ^ is calculated based on ^ and the position error Δθ^. Specifically, for example, in block 90, the estimated angular velocity ω γδ ^ or estimated angular velocity ω uvw The estimated position θ^ is calculated by adding the provisional estimated position θ1 obtained by integrating ^ and the corrected position error Δθ obtained by multiplying the position error Δθ^ by a predetermined transfer function in block 91, using the adder 92. Although the position error Δθ^ is multiplied by a predetermined transfer function, it is not always necessary to multiply by a predetermined transfer function.

[0062] Subsequently, the estimated angular velocity ω γδ ^ or estimated angular velocity ω uvw The ^ and estimated position θ^ are stored in the memory unit 4 and output to the current value conversion unit 7 and the voltage command value conversion unit 15.

[0063] Thus, in the control device 3 of the first embodiment, during the driving of the motor M, the corrected γ-axis estimated extended induced voltage e is attenuated by the first filter 82. γ ^´ and corrected δ-axis estimated extended induced voltage e δ Estimated angular velocity ω^ using ^' γδ^ is estimated, and when a request to restart motor M is received, the corrected U-phase estimated extended induced voltage e is obtained by attenuating harmonics by the second filter 86, which has a smaller time constant than the first filter 82. u ^´, Corrected V-phase estimated extended induced voltage e v ^´, and corrected W-phase estimated extended induced voltage e w Estimated angular velocity ω^ using ^' uvw This is a configuration that estimates ^.

[0064] As a result, when restarting the motor M, the delay in the convergence of the estimated angular velocity ω^ can be suppressed compared to when the estimated angular velocity ω^ is estimated based on the position error Δθ^ calculated using the corrected estimated extended induced voltage with harmonics attenuated by the first filter 82. Therefore, since the decrease in the estimation accuracy of the estimated position θ^ can be suppressed, even if the actual extended induced voltage becomes relatively high when restarting the motor M because the motor M was rotating by inertia while the control device 3 was stopped, it is possible to suppress the situation in which the motor M cannot be restarted due to an overcurrent flowing through the motor M.

[0065] Furthermore, in the control device 3 of the first embodiment, when a request to restart the motor M is received, the U-phase estimated extended induced voltage e is calculated without using the estimated angular velocity ω^. u ^, V-phase estimated extended induced voltage e v ^, W-phase estimated extended induced voltage e w This is a configuration that estimates ^.

[0066] This results in the U-phase estimated extended induced voltage e u ^, V-phase estimated extended induced voltage e v ^, W-phase estimated extended induced voltage e w Compared to estimating ^ using the estimated angular velocity ω^, the U-phase estimated extended induced voltage e u ^, V-phase estimated extended induced voltage e v ^, W-phase estimated extended induced voltage e w This improves the estimation accuracy of ^, thereby further suppressing the delay in the convergence of the estimated angular velocity ω^.

[0067] Furthermore, in the control device 3 of the first embodiment, when a request to restart the motor M is received, the U-phase current value I u V-phase current value I v W-phase current value I w U-phase voltage command value V u *, V-phase voltage command value V v *, and W-phase voltage command value V w *U phase estimation extended induced voltage e u ^, V-phase estimated extended induced voltage e v ^, W-phase estimated extended induced voltage e w This is a configuration that estimates ^.

[0068] This results in the U-phase current value I u V-phase current value I v and W-phase current value I w γ-axis current value I γ and δ-axis current value I δ When converting, the γ-axis current value I γ and δ-axis current value I δ Errors and U-phase voltage command values ​​V included u *, V-phase voltage command value V v * and W-phase voltage command value V w * is the gamma-axis voltage command value V γ * and δ-axis voltage command value V δ *When converting to the γ-axis voltage command value V γ * and δ-axis voltage command value V δ *Unaffected by errors included in the U-phase estimated extended induced voltage e u ^, V-phase estimated extended induced voltage e v ^, W-phase estimated extended induced voltage e w Since ^ can be estimated, U-phase estimated extended induced voltage e u ^, V-phase estimated extended induced voltage e v ^, W-phase estimated extended induced voltage e w This improves the estimation accuracy of ^ and further suppresses the delay in the convergence of the estimated angular velocity ω^.

[0069] Furthermore, since the control device 3 of the first embodiment is configured to calculate the estimated angular velocity ω^ by calculating the above equation 8, it is possible to further suppress the delay in the convergence of the estimated angular velocity ω^ compared to a configuration that calculates the estimated angular velocity ω^ by multiplying the position error Δθ^ by a predetermined transfer function.

[0070] <Second Embodiment> Figure 3 shows the control system in the second embodiment. In the control system 1' shown in Figure 3, the same reference numerals are used for components that are the same as those in the control system 1 shown in Figure 1, and their descriptions are omitted.

[0071] The control device 3' shown in Figure 3 differs from the control device 3 shown in Figure 1 in that it has an estimation unit 8' instead of an estimation unit 8.

[0072] Figure 4 is a block diagram corresponding to the estimation unit 8' in the second embodiment. In the estimation unit 8' shown in Figure 4, the same components as those in the estimation unit 8 shown in Figure 2 are denoted by the same reference numerals, and their descriptions are omitted.

[0073] In block 81', the estimation unit 8' receives the input γ-axis current value I γ δ-axis current value I δ γ-axis voltage command value V γ * and δ-axis voltage command value V δ *The estimated extended induced voltage e1^´ of the γ-δ axis is calculated using the observer (motor model) shown in equation 9 below. The estimated extended induced voltage e1^´ of the γ-δ axis is equal to the estimated extended induced voltage e1 of the γ axis. γ ^ and the delta-axis estimated extended induced voltage e2 δ It includes ^ and as vector components.

[0074]

number

[0075] Next, the estimation unit 8' determines the γ-axis estimated extended induced voltage e1 in the second filter 86'. γ Attenuating harmonics contained in ^ to correct the γ-axis estimated extended induced voltage e1 γIt outputs ^´ and the δ-axis estimated extended induced voltage e1 δ Attenuating harmonics contained in ^ to correct the δ-axis estimated extended induced voltage e1 δ It outputs ^´. In other words, the second filter 86´ can be said to attenuate the harmonics of the estimated extended induced voltage along the γ-δ axis. Also, the corrected γ-axis estimated extended induced voltage e1 γ ^´ and corrected delta-axis estimated extended induced voltage e1 δ ^' can be said to be the estimated extended induced voltage with harmonics attenuated by the second filter 86'. The second filter 86' is, for example, a low-pass filter using a moving average, and has a smaller time constant than the first filter 82. Furthermore, the second filter 86' is assumed to have a frequency characteristic that attenuates only harmonics, which has been determined in advance through experiments or simulations.

[0076] Then, the estimation unit 8' calculates the estimated angular velocity ω in blocks 87' and 88' by calculating the following equation 10. γδ It outputs ^'. In other words, the estimation unit 8' estimates the angular velocity using the estimated extended induced voltage, from which harmonics have been attenuated by the second filter 86'.

[0077]

number

[0078] Thus, in the control device 3' of the second embodiment, during the driving of the motor M, the corrected γ-axis estimated extended induced voltage e is attenuated by the first filter 82. γ ^´ and corrected δ-axis estimated extended induced voltage e δ Estimated angular velocity ω^ using ^' γδ ^ is estimated, and when a request to restart motor M is received, the corrected γ-axis estimated extended induced voltage e1 is obtained by attenuating harmonics by the second filter 86', which has a smaller time constant than the first filter 82. γ ^´ and corrected delta-axis estimated extended induced voltage e1 δ Estimated angular velocity ω^ using ^' γδ This is a configuration that estimates ^'.

[0079] As a result, similar to the first embodiment, when restarting the motor M, the delay in the convergence of the estimated angular velocity ω^ can be suppressed compared to when the estimated angular velocity ω^ is estimated using a corrected estimated extended induced voltage with harmonics attenuated by the first filter 82. Therefore, since the decrease in the estimation accuracy of the estimated position θ^ can be suppressed, even if the actual extended induced voltage becomes relatively high when restarting the motor M because the motor M was rotating by inertia while the control device 3' was stopped, it is possible to suppress the situation in which the motor M cannot be restarted due to an overcurrent flowing through the motor M.

[0080] Furthermore, in the control device 3' of the second embodiment, when a request to restart the motor M is received, the γ-axis estimated extended induced voltage e1 is calculated without using the estimated angular velocity ω^. γ ^ and δ axis estimated extended induced voltage e1 δ This is a configuration that estimates ^.

[0081] This results in the γ-axis estimated extended induced voltage e1 γ ^ and δ axis estimated extended induced voltage e1 δ Compared to estimating ^ using the estimated angular velocity ω^, the γ-axis estimated extended induced voltage e1 γ ^ and δ axis estimated extended induced voltage e1 δ This improves the estimation accuracy of ^, thereby further suppressing the delay in the convergence of the estimated angular velocity ω^.

[0082] It should be noted that the present invention is not limited to the embodiments described above, and various improvements and modifications are possible without departing from the spirit of the invention.

[0083] In the second embodiment, when a request to restart the motor M is received, the estimated extended induced voltage e1^´ of the γ-δ axis calculated in block 81' is input to the second filter 86', but it is not limited to this, and when a request to restart the motor M is received, the estimated extended induced voltage e1^ of the γ-δ axis calculated in block 81 is input to the second filter 86'. Alternatively, when a request to restart the motor is received, the estimated extended induced voltage e1^ of the γ-δ axis calculated in block 81 is input to the second filter 86', and the corrected estimated extended induced voltage e1 of the γ axis output from the second filter 86' is input. γ ^´ and corrected delta-axis estimated extended induced voltage e1 δ The estimated angular velocity ω is based on the position error Δθ^ calculated using ^´. γδ Alternatively, you can estimate ^', or input the estimated extended induced voltage e1^' of the γ-δ axis calculated in block 81' into the second filter 86', and output the corrected γ-axis estimated extended induced voltage e1 from the second filter 86'. γ ^´ and corrected delta-axis estimated extended induced voltage e1 δ The estimated angular velocity ω is based on the position error Δθ^ calculated using ^´. γδ You may infer ^'.

[0084] Furthermore, the first filter 82, the second filter 86, and the second filter 86' may be composed of variable filters whose time constants can be changed. [Explanation of symbols]

[0085] 1. Control System 2 Inverters 3. Control device 4 Storage section 5. Drive Circuit 6 Arithmetic section 7 Current Value Conversion Unit 8 Estimation part 9. Subtraction Unit 10 Torque command value calculation unit 11 Current command value output unit 12 Subtraction Unit 13 Subtraction Unit 14 Voltage command value calculation unit 15 Voltage command value conversion unit P power supply C Capacitor Se1 Current Sensor Se2 Current Sensor Se3 Current Sensor

Claims

1. A control device that generates U-phase voltage command values, V-phase voltage command values, and W-phase voltage command values ​​for controlling an inverter that drives a motor, An estimation unit that estimates an estimated expanded induced voltage, which is an estimated value of the expanded induced voltage generated in the motor, and estimates the angular velocity of the motor based on the estimated expanded induced voltage, A current value conversion unit that converts the U-phase current value flowing through the U-phase of the motor, the V-phase current value flowing through the V-phase, and the W-phase current value flowing through the W-phase into the γ-axis current value and the δ-axis current value, A γ-δ current command value output unit that outputs γ-axis current command values ​​and δ-axis current command values, A γ-δ voltage command value calculation unit calculates a γ-axis voltage command value based on the γ-axis current value and the γ-axis current command value, and calculates a δ-axis voltage command value based on the δ-axis current value and the δ-axis current command value, A voltage command value conversion unit converts the γ-axis voltage command value and the δ-axis voltage command value into the U-phase voltage command value, the V-phase voltage command value, and the W-phase voltage command value, respectively. Equipped with, The estimation unit, During the operation of the motor, the angular velocity is estimated using the estimated extended induced voltage of the γ-δ axis, from which harmonics have been attenuated by the first low-pass filter. When a request to restart the motor is received, the angular velocity is estimated using the estimated extended induced voltages of the U-phase, V-phase, and W-phase, from which harmonics have been attenuated by the second low-pass filter. Control device.

2. A control device that generates a U-phase voltage command value, a V-phase voltage command value, and a W-phase voltage command value for controlling an inverter that drives a motor, An estimation unit that estimates an estimated expanded induced voltage, which is an estimated value of the expanded induced voltage generated in the motor, and estimates the angular velocity of the motor based on the estimated expanded induced voltage, A current value conversion unit that converts the U-phase current value flowing through the U-phase of the motor, the V-phase current value flowing through the V-phase, and the W-phase current value flowing through the W-phase into the γ-axis current value and the δ-axis current value, A γ-δ current command value output unit that outputs γ-axis current command values ​​and δ-axis current command values, A γ-δ voltage command value calculation unit calculates a γ-axis voltage command value based on the γ-axis current value and the γ-axis current command value, and calculates a δ-axis voltage command value based on the δ-axis current value and the δ-axis current command value, A voltage command value conversion unit converts the γ-axis voltage command value and the δ-axis voltage command value into the U-phase voltage command value, the V-phase voltage command value, and the W-phase voltage command value, respectively. Equipped with, The estimation unit, During the operation of the motor, the angular velocity is estimated using the estimated extended induced voltage of the γ-δ axis, from which harmonics have been attenuated by the first low-pass filter. When a request to restart the motor is received, the angular velocity is estimated using the estimated extended induced voltage of the γ-δ axis, from which harmonics have been attenuated by the second low-pass filter. Control device.

3. A control device according to claim 2, The time constant of the second low-pass filter is smaller than the time constant of the first low-pass filter. Control device.

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