WO2024106339A1 - Convertisseur de puissance et procédé de commande de convertisseur de puissance - Google Patents

Convertisseur de puissance et procédé de commande de convertisseur de puissance Download PDF

Info

Publication number
WO2024106339A1
WO2024106339A1 PCT/JP2023/040591 JP2023040591W WO2024106339A1 WO 2024106339 A1 WO2024106339 A1 WO 2024106339A1 JP 2023040591 W JP2023040591 W JP 2023040591W WO 2024106339 A1 WO2024106339 A1 WO 2024106339A1
Authority
WO
WIPO (PCT)
Prior art keywords
current command
power conversion
control
command
value
Prior art date
Application number
PCT/JP2023/040591
Other languages
English (en)
Japanese (ja)
Inventor
徹 杉浦
徹郎 児島
Original Assignee
株式会社日立製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社日立製作所 filed Critical 株式会社日立製作所
Publication of WO2024106339A1 publication Critical patent/WO2024106339A1/fr

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
    • H02P21/34—Arrangements for starting

Definitions

  • the present invention relates to a power conversion device and a method for controlling a power conversion circuit.
  • the power conversion device When operating railway vehicles, the power conversion device is started from a stopped state, the vehicle accelerates, the power conversion device is stopped, the vehicle enters a coasting state where the vehicle runs by inertia, and from this state the power conversion device is restarted and the vehicle is accelerated or decelerated.
  • This is a common operation.
  • no voltage is applied to the induction motor, but current continues to flow inside the induction motor for a while after the power conversion device is stopped. This current is consumed by the internal resistance of the induction motor and gradually decays, but magnetic flux continues to be generated until the current disappears, so residual magnetic flux exists inside the induction motor. If the power conversion device is restarted when this residual magnetic flux is large, adverse effects such as damage to the power conversion device due to the generation of excessive current and deterioration of the vehicle's ride comfort due to the generation of excessive torque may occur.
  • Patent Document 1 discloses a control device for a power conversion device that has the function of sufficiently attenuating magnetic flux when stopping an induction motor, and includes a voltage calculation unit that generates a voltage command based on a current command, and a PWM calculation unit that outputs a gate pulse signal for the power conversion circuit based on the voltage command.
  • Patent Document 1 does not take into consideration the control required when the power conversion device is shut off during the ramp-up of the magnetic flux command. As a result, in such a case, there is a risk that the residual magnetic flux inside the induction motor will not be sufficiently attenuated.
  • a power conversion device includes a power conversion circuit that converts DC power to AC power to drive an induction motor, and a control device that outputs a gate pulse signal to the power conversion circuit to control the power conversion circuit, wherein the control device determines a current command and a magnetic flux command used in generating the gate pulse signal, and is capable of holding a hold value corresponding to the value of the magnetic flux command immediately before the current command starts to fall, and when shutting off the power conversion circuit, determines the current command and the magnetic flux command based on the held value.
  • a control method for a power conversion circuit is a control method for a power conversion circuit that converts DC power to AC power to drive an induction motor, the control method comprising the steps of: determining a current command and a magnetic flux command; generating a gate pulse signal based on the current command and the magnetic flux command; outputting the gate pulse signal to the power conversion circuit; holding a hold value corresponding to the value of the magnetic flux command immediately before the current command starts to fall; and, when shutting off the power conversion circuit, determining the current command and the magnetic flux command based on the held value.
  • the residual magnetic flux inside the induction motor can be sufficiently attenuated.
  • FIG. 1 is a diagram showing a configuration of a power conversion device according to an embodiment of the present invention
  • FIG. 2 is a functional block diagram showing details of a control device according to the first embodiment of the present invention.
  • FIG. 2 is a control block diagram showing details of a pattern generating unit according to the first embodiment of the present invention.
  • 11 is a diagram showing an example of each command and state quantity when cut-off control is performed after completion of the rise of the d-axis magnetic flux command.
  • FIG. 1 is a diagram showing an example of each command and state quantity when cutoff control is performed before the start-up of a d-axis magnetic flux command is completed by a conventional control method.
  • FIG. 1 is a diagram showing a configuration of a power conversion device according to an embodiment of the present invention
  • FIG. 2 is a functional block diagram showing details of a control device according to the first embodiment of the present invention.
  • FIG. 2 is a control block diagram showing details of a pattern generating unit according to the first embodiment of the present
  • FIG. 4 is a diagram showing an example of each command and a state quantity in a case where cutoff control is performed before the start-up of a d-axis magnetic flux command is completed in the power conversion device according to the first embodiment of the present invention.
  • FIG. FIG. 11 is a functional block diagram showing details of a control device according to a second embodiment of the present invention.
  • FIG. 11 is a control block diagram showing details of a pattern generating unit according to a second embodiment of the present invention.
  • FIG. 13 is a control block diagram showing details of a pattern generating unit according to a third embodiment of the present invention.
  • FIG. 11 is a diagram showing an example of each command and a state quantity in a case where cutoff control is performed before the start-up of a d-axis magnetic flux command is completed in a power conversion device according to a third embodiment of the present invention.
  • First Embodiment Fig. 1 is a diagram showing the configuration of a power conversion device according to an embodiment of the present invention.
  • the power conversion device shown in Fig. 1 includes a power conversion circuit 1 that is connected to an induction motor 3 and converts DC power supplied from an external DC power source into AC power and outputs the AC power to the induction motor 3 to drive the induction motor 3, and a control device 2 that controls the power conversion circuit 1.
  • the power conversion circuit 1 has a U-phase upper arm element 5a, a U-phase lower arm element 5b, a V-phase upper arm element 5c, a V-phase lower arm element 5d, a W-phase upper arm element 5e, and a W-phase lower arm element 5f, which are semiconductor switching elements.
  • the U-phase upper arm element 5a and the U-phase lower arm element 5b, the V-phase upper arm element 5c and the V-phase lower arm element 5d, and the W-phase upper arm element 5e and the W-phase lower arm element 5f are connected in series in the power conversion circuit 1, forming upper and lower arm circuits for the U, V, and W phases.
  • Power lines leading to the induction motor 3 are connected between the upper arm elements 5a, 5c, 5e and the lower arm elements 5b, 5d, 5f of each of these upper and lower arm circuits.
  • the power conversion circuit 1 converts DC power supplied from a DC power source into three-phase AC power by switching and driving the semiconductor switching elements 5a to 5f in response to the gate pulse signals Su1, Su2, Sv1, Sv2, Sw1, and Sw2 output from the control device 2.
  • the converted three-phase AC power is output from the power conversion circuit 1 to the induction motor 3 via the power lines of each phase, thereby controlling the drive of the induction motor 3 by the power conversion device of this embodiment.
  • the DC power supplied from the DC power source is smoothed by the smoothing capacitor 4 and input to the power conversion circuit 1.
  • the terminal voltage of the smoothing capacitor 4 i.e., the voltage Ecf of the DC power input to the power conversion circuit 1, is detected by the DC voltage sensor 6, and the detected value is input to the control device 2.
  • a U-phase current sensor 7a, a V-phase current sensor 7b, and a W-phase current sensor 7c are installed on the power lines of each phase between the power conversion circuit 1 and the induction motor 3 to detect the U-phase current iu, the V-phase current iv, and the W-phase current iw that flow through the induction motor 3.
  • the detection results of each phase current by these current sensors 7a to 7c are input to the control device 2.
  • the control device 2 generates gate pulse signals Su1, Su2, Sv1, Sv2, Sw1, and Sw2 based on the detection value of the DC voltage Ecf by the DC voltage sensor 6 and the detection values of the U-phase current iu, V-phase current iv, and W-phase current iw by the current sensors 7a to 7c, and outputs them to the power conversion circuit 1.
  • FIG. 2 is a functional block diagram showing details of the control device 2 according to the first embodiment of the present invention.
  • the control device 2 has the following functional blocks: a current command generation unit 8, a pattern generation unit 9, a coordinate conversion unit 10, a rotational speed estimation unit 11, a frequency command generation unit 12, a voltage command generation unit 13, and a pulse command generation unit 14.
  • the control device 2 is configured using, for example, a microcomputer having a CPU, memory, etc., and can realize functions corresponding to each functional block in FIG. 2 by executing a predetermined program in the CPU. Note that some or all of the functions of the control device 2 may be realized using a logic circuit such as an FPGA (Field Programmable Gate Array).
  • FPGA Field Programmable Gate Array
  • the control device 2 receives a control command cmd from the outside to operate or stop the power conversion circuit 1.
  • the current command generation unit 8 generates and outputs a d-axis current command Idp1 and a q-axis current command Iqp according to the control command cmd. For example, when a control command cmd to operate the power conversion circuit 1 is input, the current command generation unit 8 generates a d-axis current command Idp1 and a q-axis current command Iqp so that the AC power required to drive the induction motor 3 with a specified torque is output from the power conversion circuit 1.
  • the pattern generation unit 9 calculates the excitation current command Idp2 and the d-axis magnetic flux command ⁇ dp based on the d-axis current command Idp1 input from the current command generation unit 8, and outputs them to the voltage command generation unit 13.
  • the excitation current command Idp2 is a command value for the current in the d-axis direction, which is the direction of the rotating magnetic field of the induction motor 3. It is equal to the d-axis current command Idp1 during normal operation of the power conversion circuit 1, and corresponds to a corrected value obtained by correcting the d-axis current command Idp1 to attenuate the magnetic flux of the induction motor 3 when the power conversion circuit 1 is stopped.
  • the pattern generation unit 9 switches the calculation method of the excitation current command Idp2 and the d-axis magnetic flux command ⁇ dp depending on the control state of the induction motor 3.
  • the calculation method of the excitation current command Idp2 and the d-axis magnetic flux command ⁇ dp by the pattern generation unit 9 will be described in detail later.
  • the coordinate conversion unit 10 performs a rotational coordinate conversion on the U-phase current iu, V-phase current iv, and W-phase current iw detected by the current sensors 7a to 7c, respectively, to determine the d-axis current detection value Idf and the q-axis current detection value Iqf, and outputs these current detection values to the rotation speed estimation unit 11. Note that the coordinate conversion unit 10 determines the d-axis current detection value Idf and the q-axis current detection value Iqf by defining the direction of the rotating magnetic field of the induction motor 3 as the d-axis direction and the direction of the current flowing to generate torque as the q-axis direction.
  • the rotational speed estimation unit 11 estimates the rotor angular frequency of the induction motor 3 based on the excitation current command Idp2 and the q-axis current command Iqp input from the pattern generation unit 9 and the current command generation unit 8, respectively, and the d-axis current detection value Idf and the q-axis current detection value Iqf input from the coordinate conversion unit 10, and outputs the estimation result as the rotor angular frequency estimate value ⁇ re.
  • the frequency command generating unit 12 receives the d-axis magnetic flux command ⁇ dp calculated by the pattern generating unit 9, the q-axis current command Iqp generated by the current command generating unit 8, and the rotor angular frequency estimate ⁇ re estimated by the rotational speed estimating unit 11. Based on this input information, the frequency command generating unit 12 calculates the angular frequency of the AC voltage applied to the induction motor 3, and outputs it as the primary angular frequency ⁇ 1.
  • the voltage command generating unit 13 receives as input the DC voltage Ecf detected by the DC voltage sensor 6, the excitation current command Idp2 and the d-axis magnetic flux command ⁇ dp calculated by the pattern generating unit 9, the q-axis current command Iqp generated by the current command generating unit 8, the rotor angular frequency estimate ⁇ re calculated by the rotational speed estimating unit 11, and the primary angular frequency ⁇ 1 calculated by the frequency command generating unit 12.
  • the voltage command generating unit 13 calculates the modulation factor Vc and voltage command deflection angle ⁇ of the power conversion circuit 1 based on this input information, and outputs the calculation result as a voltage command for the output voltage from the power conversion circuit 1 to the induction motor 3.
  • the pulse command generating unit 14 calculates gate pulse signals Su1, Su2, Sv1, Sv2, Sw1, and Sw2 for the semiconductor switching elements 5a to 5f of the power conversion circuit 1 based on the modulation factor Vc and voltage command argument ⁇ , which are voltage commands generated by the voltage command generating unit 13, and the primary angular frequency ⁇ 1 determined by the frequency command generating unit 12.
  • the gate pulse signals Su1, Su2, Sv1, Sv2, Sw1, and Sw2 determined by the pulse command generating unit 14 are output from the control device 2 to the power conversion circuit 1 as described above, and are used to control the drive of each of the semiconductor switching elements 5a to 5f of the power conversion circuit 1.
  • FIG. 2 shows an example of a power conversion device that realizes speed sensorless control by using the rotation speed estimation unit 11 to determine the rotor angular frequency estimate ⁇ re of the induction motor 3.
  • the present invention will be explained below using this example, but the present invention can also be applied to speed sensor-equipped control in which a speed sensor is provided instead of the rotation speed estimation unit 11 and the rotation speed of the induction motor 3 is detected by this speed sensor.
  • the configuration of the present invention is not limited to the embodiment described below.
  • FIG. 3 is a control block diagram showing details of the pattern generation unit 9 according to the first embodiment of the present invention.
  • the pattern generation unit 9 is configured by combining a switching contact 15, an adder 16, a switching contact 17, a delay element 18, a subtractor 19, a gain 20, an integral element 21, a switching contact 22, a gain 23, a switching contact 24, a delay element 25, a multiplier 26, a divider 27, a gain 28, and a differential element 29, for example, as shown in FIG. 3.
  • the pattern generation unit 9 switches the calculation method of the excitation current command Idp2 and the d-axis magnetic flux command ⁇ dp depending on the control state of the induction motor 3. Specifically, the calculation method of the excitation current command Idp2 and the d-axis magnetic flux command ⁇ dp in the pattern generation unit 9 is switched between a case where the operation of the power conversion circuit 1 is controlled so that AC power is output from the power conversion circuit 1 to drive the induction motor 3 with a predetermined torque (hereinafter referred to as "normal control") and a case where the operation of the power conversion circuit 1 is controlled so that the output of AC power from the power conversion circuit 1 to the induction motor 3 is cut off (hereinafter referred to as "cut-off control").
  • This switching of the calculation method can be performed, for example, based on the control command cmd input to the control device 2.
  • the switching contact 15 switches the excitation current command Idp2 output from the pattern generating unit 9.
  • the pattern generating unit 9 switches the switching contact 15 so that during normal control, it outputs the d-axis current command Idp1 input from the current command generating unit 8 as the excitation current command Idp2, and during cut-off control, it outputs the output of the adder 16 as the excitation current command Idp2.
  • Adder 16 adds the output of differential element 29 to d-axis current command Idp1. This added value is output from adder 16 via switching contact 15 as excitation current command Idp2 during cutoff control, as described above.
  • the switching contact 17 switches the d-axis current command hold value Idph.
  • the pattern generating unit 9 switches the switching contact 17 so that the d-axis current command Idp1 output from the current command generating unit 8 and input to the pattern generating unit 9 is the d-axis current command hold value Idph, and during cut-off control, the pattern generating unit 9 switches the switching contact 17 so that the output of the delay element 18 is the d-axis current command hold value Idph.
  • the delay element 18 delays the output of the switching contact 17 and outputs it.
  • the d-axis current command hold value Idph is successively updated according to the value of the d-axis current command Idp1 input from the current command generation unit 8 to the pattern generation unit 9.
  • the value of the d-axis current command Idp1 input from the current command generation unit 8 to the pattern generation unit 9 immediately before switching is held as the d-axis current command hold value Idph.
  • Subtractor 19 subtracts the output of integral element 21 from d-axis current command Idp1. This subtracted value is output to gain 20.
  • Gain 20 multiplies the output of subtractor 19 by the inverse of the preset secondary time constant T2 of induction motor 3. This multiplied value is output to integral element 21.
  • Integral element 21 accumulates the output of gain 20. This accumulated value is output to integral element 21, switching contact 22, and switching contact 24.
  • the switching contact 22 switches the magnetization current command I0 input to the gain 23.
  • the pattern generating unit 9 switches the switching contact 22 so that during normal control, the output of the integral element 21 is input to the gain 23 as the magnetization current command I0, and during cut-off control, the pattern generating unit 9 switches the switching contact 22 so that the output of the divider 27 is input to the gain 23 as the magnetization current command I0.
  • Gain 23 multiplies the magnetization current command I0 input from switching contact 22 by the preset excitation inductance L of induction motor 3. This multiplied value is output from pattern generator 9 as d-axis magnetic flux command ⁇ dp.
  • the switching contact 24 switches the magnetization current command holding value I0h.
  • the pattern generating unit 9 switches the switching contact 24 so that the output of the integral element 21 is the magnetization current command holding value I0h during normal control, and the output of the delay element 25 is the magnetization current command holding value I0h during cut-off control.
  • the delay element 25 delays the output of the switching contact 24 and outputs it.
  • the magnetization current command holding value I0h is successively updated according to the value of the magnetization current command I0 output from the integral element 21 and input to the gain 23.
  • the value of the magnetization current command I0 input to the gain 23 immediately before switching is held as the magnetization current command holding value I0h.
  • the multiplier 26 multiplies the d-axis current command Idp1 by the magnetization current command hold value I0h. This multiplied value is output to the divider 27.
  • the divider 27 divides the output of the multiplier 26 by the d-axis current command hold value Idph. This divided value is output to the switching contact 22 and the gain 28.
  • Gain 28 multiplies the output of divider 27 by a preset secondary time constant T2 of induction motor 3. This multiplied value is output to differential element 29.
  • the differential element 29 calculates the amount of change over time in the output of the gain 28. This calculated value is output to the adder 16.
  • the excitation current command Idp2 and magnetization current command I0 are obtained based on the d-axis current command Idp1 through the operation of each component as described above, and the d-axis magnetic flux command ⁇ dp can be generated based on the magnetization current command I0 and the excitation inductance L preset according to the characteristics of the induction motor 3.
  • the excitation current command Idp2 can be obtained from the d-axis current command Idp1
  • the magnetization current command I0 can be obtained based on the d-axis current command Idp1 and the secondary time constant T2 preset according to the characteristics of the induction motor 3.
  • the magnetization current command I0 can be obtained based on the d-axis current command Idp1, the magnetization current command hold value I0h, and the d-axis current command hold value Idph, and the excitation current command Idp2 can be obtained based on the magnetization current command I0 and the secondary time constant T2.
  • FIG. 4 shows an example of each command and state quantity when cutoff control is performed after the d-axis magnetic flux command ⁇ dp has been fully started. Note that FIG. 4 shows an example of the operation of a power conversion device when the control device 2 described in FIG. 2 and FIG. 3 is used as an application example of the present invention, but similar results can be obtained with a conventional control method to which the present invention is not applied.
  • the switching contacts 15, 17, 22, and 24 are each in the normal switching state. In the example of Figure 4, this state continues from the start of the rise of the d-axis current command Idp1 until it reaches a constant value and immediately before it is cut off.
  • the cut-off command is in the on state, i.e., while cut-off control is being performed, in the pattern generation unit 9, as described above, the switching contacts 15, 17, 22, and 24 are each in the cut-off switching state. In the example of Figure 4, this state continues from the fall of the d-axis current command Idp1 until it reaches zero.
  • the d-axis current command Idp1 is shown by a solid line
  • the magnetization current command I0 is shown by a dashed line superimposed on it.
  • the magnetization current command I0 acts as a first-order lag with a second-order time constant T2 relative to the d-axis current command Idp1 due to the operation of the subtractor 19, gain 20, integral element 21, and switching contact 22.
  • the d-axis current command Idp1 After the d-axis current command Idp1 finishes rising and reaches a constant value, when sufficient time has passed, the d-axis current command Idp1 and the magnetization current command I0 will match, as shown in Figure 4. Therefore, in the example of Figure 4, during the interruption control, the d-axis current command Idp1 and the magnetization current command I0 will be the same value due to the operation of the multiplier 26, the divider 27, and the switching contact 22.
  • the excitation current command Idp2 becomes the same value as the d-axis current command Idp1 during normal control, and during cut-off control, becomes the value obtained by multiplying the time rate of change of the magnetization current command I0 (dI0/dt) by the secondary time constant T2 and adding it to the d-axis current command Idp1.
  • the d-axis magnetic flux command ⁇ dp is the magnetization current command I0 multiplied by the excitation inductance L.
  • the steady-state value of the excitation current command Idp2 is defined as Idp0.
  • the value of the d-axis current command Idp1 coincides with the excitation current command Idp2 and the magnetization current command I0.
  • the value of the d-axis magnetic flux command ⁇ dp at this time is equal to the value obtained by multiplying the steady-state value Idp0 of the excitation current command Idp2 by the excitation inductance L.
  • the d-axis magnetic flux ⁇ d can be reduced to zero without undershooting the command value by the d-axis magnetic flux command ⁇ dp. This allows the d-axis magnetic flux ⁇ d to be attenuated without remaining when the power conversion circuit 1 is cut off.
  • Figure 5 is a diagram showing an example of each command and state quantity when cutoff control is performed before the rise of the d-axis magnetic flux command ⁇ dp is completed using a conventional control method. Unlike Figure 4, Figure 5 shows an example of an operation waveform in which the d-axis current command Idp1 falls after the d-axis magnetic flux command ⁇ dp starts to rise and before it reaches a constant value. Note that explanations of each command and state quantity in Figure 5 that behave in the same way as in Figure 4 will be omitted below.
  • the d-axis magnetic flux command ⁇ dp when the d-axis magnetic flux command ⁇ dp has completed rising and is at a constant value as shown in FIG. 4, the d-axis magnetic flux ⁇ d can be sufficiently attenuated when transitioning from normal control to cutoff control.
  • the d-axis magnetic flux command ⁇ dp becomes discontinuous as shown in FIG. 5, and an excessively large command value is output as the d-axis magnetic flux command ⁇ dp.
  • the d-axis magnetic flux ⁇ d crosses zero and undershoots, so that the d-axis magnetic flux ⁇ d remains inside the induction motor 3 even after the power conversion device is stopped. If the power conversion device is restarted in this state where the d-axis magnetic flux ⁇ d remains inside the induction motor 3, excessive current and torque will be generated. To prevent this, even if transitioning from normal control to cutoff control occurs during the rise of the d-axis magnetic flux command ⁇ dp, it is necessary that the d-axis magnetic flux command ⁇ dp does not become discontinuous and that the d-axis magnetic flux ⁇ d is attenuated at a constant rate of change until it reaches zero.
  • the power conversion device of this embodiment solves the above-mentioned problems and provides a means for sufficiently attenuating the magnetic flux of the induction motor 3 when the power conversion device is shut down.
  • the switching contact 17 and delay element 18 are used to hold the d-axis current command Idp1 immediately before switching from normal control to shut-down control as the d-axis current command hold value Idph
  • the switching contact 24 and delay element 25 are used to hold the magnetization current command I0 immediately before switching from normal control to shut-down control as the magnetization current command hold value I0h.
  • the multiplier 26 and divider 27 then multiply the d-axis current command Idp1 by the magnetization current command hold value I0h and divide the result by the d-axis current command hold value Idph to calculate the magnetization current command I0 during the shut-down control.
  • the d-axis current command Idp1 can be corrected by the ratio of the d-axis current command holding value Idph to the magnetization current command holding value I0h immediately before that.
  • the magnetization current command I0 can be made a continuous value, and the magnetization current command I0 can be used to calculate the d-axis flux command ⁇ dp, which decreases continuously.
  • the d-axis flux ⁇ d is attenuated at a constant rate of change until it reaches zero, preventing the d-axis flux ⁇ d from remaining inside the induction motor 3.
  • the d-axis magnetic flux command ⁇ dp is calculated based on the corrected value of the d-axis current command Idp1. Therefore, during the fall time of the d-axis current command Idp1 (d-axis current command fall time Td), the d-axis magnetic flux command ⁇ dp can be fallen at a constant rate of change from just before interruption to zero.
  • FIG. 6 is a diagram showing an example of each command and state quantity when cutoff control is performed before the start-up of the d-axis magnetic flux command ⁇ dp is completed in the power conversion device according to the first embodiment of the present invention. Note that in FIG. 6, the commands and state quantities that behave in the same way as in FIG. 4 will not be described below.
  • the value of the excitation current command Idp2 during interruption control is calculated by multiplying the time rate of change of the magnetization current command I0 (dI0/dt) by the secondary time constant T2 of the induction motor 3 and adding this to the d-axis current command Idp1. Since the magnetization current command I0 decreases at a constant rate of change, the value of the excitation current command Idp2 at this time is the value obtained by translating the d-axis current command Idp1 in the negative direction.
  • the actual d-axis magnetic flux ⁇ d in the induction motor 3 can be lowered at a constant rate of change.
  • the d-axis magnetic flux ⁇ d can be attenuated to zero without undershooting.
  • the residual amount of the d-axis magnetic flux ⁇ d when the power conversion device is cut off can be made zero. Therefore, the generation of excessive current and torque when the power conversion device is restarted can be suppressed.
  • the first embodiment of the present invention described above provides the following effects.
  • the power conversion device includes a power conversion circuit 1 that converts DC power into AC power to drive an induction motor 3, and a control device 2 that outputs gate pulse signals Su1, Su2, Sv1, Sv2, Sw1, and Sw2 to the power conversion circuit 1 to control the power conversion circuit 1.
  • the control device 2 determines the d-axis current command Idp1, the excitation current command Idp2, and the d-axis flux command ⁇ dp used to generate the gate pulse signals Su1, Su2, Sv1, Sv2, Sw1, and Sw2, and is capable of holding a magnetization current command holding value I0h and a d-axis current command holding value Idph according to the value of the d-axis flux command ⁇ dp immediately before the d-axis current command Idp1 starts to fall, and determines the d-axis current command Idp1, the excitation current command Idp2, and the d-axis flux command ⁇ dp based on these held values when the power conversion circuit 1 is shut off. This allows the residual magnetic flux inside the induction motor 3 to be sufficiently attenuated even if the power conversion device is shut off while the d-axis magnetic flux command ⁇ dp is rising.
  • a control command cmd for operating or stopping the power conversion circuit 1 is input to the control device 2. Based on the control command cmd, the control device 2 performs either normal control for the period before the d-axis current command Idp1 starts to fall, or interruption control for the period after the d-axis current command Idp1 starts to fall, and is capable of holding a holding value corresponding to the value of the d-axis magnetic flux command ⁇ dp immediately before switching from normal control to interruption control.
  • the control device 2 has a current command generating unit 8 that generates a d-axis current command Idp1 and a q-axis current command Iqp according to the control command cmd, a pattern generating unit 9 that determines an excitation current command Idp2 and a magnetization current command I0 based on the d-axis current command Idp1 and generates a d-axis magnetic flux command ⁇ dp based on the magnetization current command I0 and an excitation inductance L that is preset according to the characteristics of the induction motor 3, a voltage command generating unit 13 that generates a voltage command based on the excitation current command Idp2, the d-axis magnetic flux command ⁇ dp, and the q-axis current command Iqp, and a pulse command generating unit 14 that generates gate pulse signals Su1, Su2, Sv1, Sv2, Sw1, Sw2 based on the voltage command.
  • the pattern generating unit 9 holds the value of the magnetization current command I0 immediately before switching from the normal control to the cutoff control as a magnetization current command holding value I0h. By doing this, when the power conversion device is shut off during the rise of the d-axis magnetic flux command ⁇ dp, gate pulse signals Su1, Su2, Sv1, Sv2, Sw1, and Sw2 can be generated that can sufficiently attenuate the residual magnetic flux inside the induction motor 3.
  • the pattern generator 9 uses the switch contact 15 to determine the excitation current command Idp2 from the d-axis current command Idp1, and uses the subtractor 19, gain 20, integral element 21, and switch contact 22 to determine the magnetization current command I0 based on the d-axis current command Idp1 and a secondary time constant T2 preset according to the characteristics of the induction motor 3.
  • the pattern generator 9 uses the switch contact 24, delay element 25, multiplier 26, and divider 27 to determine the magnetization current command I0 based on the d-axis current command Idp1, the magnetization current command hold value I0h, and the d-axis current command hold value Idph, and uses the gain 28, differential element 29, and adder 16 to determine the excitation current command Idp2 based on the magnetization current command I0 and the secondary time constant T2.
  • the values of the excitation current command Idp2 and magnetization current command I0 required to generate the gate pulse signals Su1, Su2, Sv1, Sv2, Sw1, and Sw2 can be appropriately determined in both normal control and interruption control.
  • the pattern generation unit 9 continues to hold the magnetization current command hold value I0h and the d-axis current command hold value Idph. Specifically, the pattern generation unit 9 holds the value of the magnetization current command I0 and the value of the excitation current command Idp2 immediately before switching from normal control to interruption control as the magnetization current command hold value I0h and the d-axis current command hold value Idph, respectively, using the switching contact 24 and delay element 25, and the switching contact 17 and delay element 18.
  • the multiplier 26 and divider 27 divide the product of the d-axis current command Idp1 and the magnetization current command hold value I0h by the d-axis current command hold value Idph to obtain the value of the magnetization current command I0 during the interruption control. In this way, even if the control transitions to the interruption control during the rise of the d-axis magnetic flux command ⁇ dp, the value of the magnetization current command I0, which changes continuously, can be calculated. As a result, the d-axis magnetic flux ⁇ d is attenuated at a constant rate until it reaches zero, and the d-axis magnetic flux ⁇ d is reliably prevented from remaining inside the induction motor 3.
  • the power conversion device of this embodiment has a similar configuration to the power conversion device of FIG. 1 described in the first embodiment, but the functional configuration of the control device 2 is different.
  • FIG. 7 is a functional block diagram showing details of a control device 2 according to a second embodiment of the present invention.
  • the pattern generator 9 is replaced with a pattern generator 9A, and in addition to the d-axis current command Idp1, the current command generator 8 outputs the d-axis current command fall time Td to the pattern generator 9A.
  • the pattern generator 9A uses the d-axis current command fall time Td to calculate the magnetization current command I0 and the d-axis magnetic flux command ⁇ dp at the time of interruption.
  • FIG. 8 is a control block diagram showing details of a pattern generator 9A according to a second embodiment of the present invention.
  • the pattern generator 9A of this embodiment adds an input of the d-axis current command fall time Td, and is configured with a divider 30, gain 31, and switch contact 32 instead of the switch contact 17, delay element 18, switch contact 22, multiplier 26, divider 27, and differential element 29 in the pattern generator 9 of FIG. 3 described in the first embodiment.
  • the divider 30 divides the magnetization current command holding value I0h by the d-axis current command falling time Td. This divided value is output to the gain 31.
  • Gain 31 inverts the output of divider 30 by multiplying it by -1, and outputs it to gain 28 and switching contact 32.
  • the differential element 29 is not provided on the output side of the gain 28. Therefore, the gain 28 multiplies the output of the divider 30, the sign of which has been inverted by the gain 31, by the secondary time constant T2 of the induction motor 3, and outputs the result to the adder 16.
  • the switching contact 32 switches the value input to the integral element 21.
  • the pattern generating unit 9A switches the switching contact 32 so that the output of the gain 20 is input to the integral element 21 during normal control, and the output of the gain 31 is input to the integral element 21 during cutoff control.
  • the d-axis current command fall time Td is used instead of the d-axis current command holding value Idph described in the first embodiment to calculate the excitation current command Idp2 and magnetization current command I0 at the time of cutoff, and the d-axis magnetic flux command ⁇ dp is obtained.
  • the pattern generator 9A also uses the gain 31 to invert the sign of the value obtained by dividing the magnetization current command holding value I0h by the d-axis current command fall time Td. This process corresponds to the calculation of the time rate of change of the magnetization current command I0 performed by the differential element 29 in the first embodiment. In other words, in this embodiment, the excitation current command Idp2 at the time of interruption can be obtained without using the differential element 29.
  • the integral element 21 is configured to integrate the ratio of the d-axis current command fall time Td to the magnetization current command holding value I0h during interruption control, the integral element 21 can be shared between normal operation and interruption. Therefore, it is possible to reliably guarantee the continuity of the d-axis magnetic flux command ⁇ dp when transitioning from normal operation control to interruption control.
  • the magnetization current command I0 that decreases at a constant rate when the current is cut off is calculated based on the ratio of the d-axis current command fall time Td to the magnetization current command hold value I0h, but this embodiment does not need to be limited to this configuration.
  • the input to the rate of change limiter is set to a value obtained by subtracting the magnetization current command I0 from zero, and the output is limited by the ratio of the d-axis current command fall time Td to the magnetization current command hold value I0h, thereby realizing a magnetization current command I0 that decreases at a constant rate.
  • the d-axis magnetic flux command ⁇ dp when the state transition occurs from normal control to cut-off control during the rise of the d-axis magnetic flux command ⁇ dp, the d-axis magnetic flux command ⁇ dp can be lowered continuously and at a constant rate, so that the d-axis magnetic flux ⁇ d can be attenuated to zero without undershooting. In other words, the residual amount of the d-axis magnetic flux ⁇ d when the power conversion device is cut off can be made zero. This makes it possible to suppress the generation of excessive current and torque when the power conversion device is restarted.
  • the differential element 29 described in the first embodiment is not necessary, so even if the d-axis current command Idp1 suddenly changes due to the influence of a disturbance at the time of interruption, the excitation current command Idp2 does not diverge, and the power conversion device can operate stably.
  • the pattern generating unit 9A continues to hold the magnetization current command holding value I0h after switching from normal control to interruption control. Specifically, the current command generating unit 8 outputs the d-axis current command falling time Td, which represents the time from the start to the end of the fall of the d-axis current command Idp1.
  • the pattern generating unit 9A holds the value of the magnetization current command I0 immediately before switching from normal control to interruption control as the magnetization current command holding value I0h using the switching contact 24 and delay element 25.
  • the divider 30, gain 31, and integral element 21 calculate the value obtained by dividing the magnetization current command holding value I0h by the d-axis current command falling time Td, and then inverting the sign of the value to obtain the value of the magnetization current command I0 during the interruption control.
  • the value of the magnetization current command I0 which changes continuously, can be calculated.
  • the d-axis magnetic flux ⁇ d is attenuated at a constant rate until it reaches zero, and the d-axis magnetic flux ⁇ d is reliably prevented from remaining inside the induction motor 3.
  • FIG. 9 is a control block diagram showing details of a pattern generator 9B according to a third embodiment of the present invention.
  • the pattern generator 9B of this embodiment is configured with a switch contact 32, a minimum limiter 33, and a gain 34, instead of the switch contact 17, delay element 18, switch contact 22, switch contact 24, delay element 25, multiplier 26, divider 27, and differential element 29 in the pattern generator 9 of FIG. 3 described in the first embodiment.
  • the minimum value limiter 33 limits the output from the subtractor 19 to an upper limit value of 0 and outputs it to the gain 34. In other words, if the magnitude of the difference between the d-axis current command Idp1 and the magnetization current command I0 calculated by the subtractor 19 is a negative value, the value is output as is to the gain 34, and if it is a positive value, the upper limit value of 0 is output to the gain 34.
  • Gain 34 multiplies the output of minimum limiter 33 by the inverse of the preset primary time constant T ⁇ of induction motor 3. This multiplied value is output from gain 34 to switching contact 32 and gain 28.
  • the differential element 29 is not provided on the output side of the gain 28. Therefore, the gain 28 is limited to a range equal to or less than the upper limit value 0 by the minimum value limiter 33, and the difference between the d-axis current command Idp1 and the magnetization current command I0 multiplied by the reciprocal of the primary time constant T ⁇ by the gain 34 is multiplied by the secondary time constant T2 of the induction motor 3 and output to the adder 16.
  • the switching contact 32 switches the value input to the integral element 21.
  • the pattern generating unit 9B switches the switching contact 32 so that the output of the gain 20 is input to the integral element 21 during normal control, and the output of the gain 34 is input to the integral element 21 during cut-off control.
  • the excitation current command Idp2 and magnetization current command I0 during cut-off are calculated using the primary time constant T ⁇ instead of the d-axis current command holding value Idph described in the first embodiment, and the d-axis magnetic flux command ⁇ dp is obtained.
  • the pattern generating unit 9B of this embodiment normally operates as a first-order lag with the secondary time constant T2 as a time constant, as in the first embodiment, through the subtractor 19, gain 20, and integral element 21 via the switching contact 32.
  • the time constant during cut-off only needs to be sufficiently short compared to the secondary time constant T2, so it is not limited to the primary time constant T ⁇ of the induction motor 3, and other time constants may be used.
  • the time constant of the first-order lag element is switched from the second-order time constant T2 to the first-order time constant T ⁇ .
  • the first-order time constant T ⁇ is sufficiently short compared to the second-order time constant T2
  • the fall rate and fall time of the d-axis flux command ⁇ dp at the time of interruption almost match the d-axis current command Idp1.
  • the integral element 21 that constitutes the first-order lag element maintains the continuity of the d-axis flux command ⁇ dp. Therefore, even if the state transition occurs from normal control to interruption control during the rise of the d-axis flux command ⁇ dp, the d-axis flux command ⁇ dp can be continuously fallen at a constant rate.
  • the output of the gain 34 is multiplied by the secondary time constant T2 using the gain 28 and the adder 16, and the result is added to the d-axis current command Idp1 to obtain the excitation current command Idp2 at the time of interruption. Since the output of the gain 34 is equal to the time rate of change of the magnetization current command I0, this makes it possible to calculate the excitation current command Idp2 required for the continuous operation of the d-axis magnetic flux command ⁇ dp.
  • the interrupt control starts in a state where the d-axis current command Idp1 is greater than the magnetization current command I0. If the minimum value limiter 33 does not exist in the configuration of the pattern generator 9B shown in FIG. 9, the subtractor 19, gain 34, and integral element 21 are configured as first-order lag elements, so that the output of the subtractor 19 becomes positive even though the d-axis current command Idp1 decreases. As a result, the magnetization current command I0 operates largely in the positive direction, which is the opposite direction to the d-axis current command Idp1.
  • a minimum value limiter 33 is provided in front of the gain 34, which limits the output of the subtractor 19 to a negative value less than zero and inputs it to the gain 34.
  • FIG. 10 is a diagram showing an example of each command and state quantity when cutoff control is performed before the start-up of the d-axis magnetic flux command ⁇ dp is completed in a power conversion device according to a third embodiment of the present invention. Note that in FIG. 10, the commands and state quantities that behave in the same way as in FIG. 4 will not be described below.
  • the d-axis flux command ⁇ dp does not become discontinuous as shown in FIG. 10.
  • the time constant of the primary lag element from the secondary time constant T2 to the primary time constant T ⁇ , the increase in the d-axis flux command ⁇ dp at cutoff can be suppressed.
  • the d-axis flux command ⁇ dp is output at a constant value, and in the period after the d-axis current command Idp1 matches the magnetization current command I0, the d-axis flux command ⁇ dp decreases at a constant rate of change. This makes it possible to decrease the d-axis flux command ⁇ dp all the way to zero within the d-axis current command fall time Td.
  • the actual d-axis magnetic flux ⁇ d in the induction motor 3 can be continuously lowered at a constant rate of change, so the d-axis magnetic flux ⁇ d can be attenuated to zero without undershooting.
  • the residual amount of d-axis magnetic flux ⁇ d can be made zero when the power conversion device is cut off and the drive of the induction motor 3 is stopped. This makes it possible to suppress the generation of excessive current and torque when the power conversion device is restarted.
  • the pattern generating unit 9B uses the integral element 21, which is an integrator, to hold a holding value corresponding to the value of the d-axis magnetic flux command ⁇ dp immediately before the start of the fall of the d-axis current command Idp1. Specifically, the pattern generating unit 9B uses the subtractor 19 to obtain the difference between the d-axis current command Idp1 and the output of the integral element 21.
  • the gain 20 and the switching contact 32 obtain the output of the integral element 21 when the product of the difference and the reciprocal of the secondary time constant T2 is input to the integral element 21 as the magnetization current command I0
  • the gain 34 and the switching contact 32 obtain the output of the integral element 21 when the product of the difference and the reciprocal of the primary time constant T ⁇ , which is shorter than the secondary time constant T2, is input to the integral element 21 as the magnetization current command I0.
  • the pattern generating unit 9B has a minimum value limiter 33 that limits the input of the integral element 21 to a range of 0 or less during cutoff control.
  • the value of the magnetization current command I0 which changes continuously, can be calculated.
  • the d-axis magnetic flux ⁇ d is attenuated at a constant rate of change until it reaches zero, and the d-axis magnetic flux ⁇ d can be reliably prevented from remaining inside the induction motor 3.
  • the present invention is not limited to the above-described embodiments and modifications, and can be implemented using any components without departing from the spirit of the invention.
  • Each embodiment and modification may be used alone, or multiple embodiments and modifications may be used in any combination.
  • the present invention can achieve the above-described effects by combining the features of each embodiment in any combination.
  • 1...power conversion circuit 2...control device, 3...induction motor, 4...smoothing capacitor, 5a...U-phase upper arm element, 5b...U-phase lower arm element, 5c...V-phase upper arm element, 5d...V-phase lower arm element, 5e...W-phase upper arm element, 5f...W-phase lower arm element, 6...DC voltage sensor, 7a...U-phase current sensor, 7b...V-phase current sensor, 7c...W-phase current sensor, 8...current command generation unit, 9, 9A, 9B...pattern generation unit, 10...coordinate conversion unit, 1 1...rotation speed estimation unit, 12...frequency command generation unit, 13...voltage command generation unit, 14...pulse command generation unit, 15...switching contact, 16...adder, 17...switching contact, 18...delay element, 19...subtractor, 20...gain, 21...integral element, 22...switching contact, 23...gain, 24...switching contact, 25...delay element, 26...multiplier, 27...divider, 28...gain

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Control Of Ac Motors In General (AREA)

Abstract

La présente invention concerne un convertisseur de puissance comprenant : un circuit convertisseur de puissance qui convertit le courant continu en courant alternatif pour entraîner un moteur à induction ; et un dispositif de commande qui émet un signal d'impulsion de grille vers le circuit convertisseur de puissance pour commander ce dernier. Le dispositif de commande peut déterminer une commande de courant et une commande de flux magnétique qui sont utilisées pour générer le signal d'impulsion de grille, et maintenir une valeur de maintien correspondant à la valeur de la commande de flux magnétique immédiatement avant le début de la chute de la commande de courant. Lors de l'interruption du convertisseur de puissance, le dispositif de commande détermine la commande de courant et la commande de flux magnétique sur la base de la valeur de maintien.
PCT/JP2023/040591 2022-11-15 2023-11-10 Convertisseur de puissance et procédé de commande de convertisseur de puissance WO2024106339A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022-182872 2022-11-15
JP2022182872 2022-11-15

Publications (1)

Publication Number Publication Date
WO2024106339A1 true WO2024106339A1 (fr) 2024-05-23

Family

ID=91084717

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/040591 WO2024106339A1 (fr) 2022-11-15 2023-11-10 Convertisseur de puissance et procédé de commande de convertisseur de puissance

Country Status (1)

Country Link
WO (1) WO2024106339A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5492178B2 (ja) * 2011-12-12 2014-05-14 株式会社東芝 可変磁束ドライブシステム
JP5812476B2 (ja) * 2011-08-02 2015-11-11 学校法人 東洋大学 永久磁石回転電機及びその運転方法
JP6410939B2 (ja) * 2015-07-10 2018-10-24 三菱電機株式会社 モータ制御装置、圧縮機、及び空気調和機

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5812476B2 (ja) * 2011-08-02 2015-11-11 学校法人 東洋大学 永久磁石回転電機及びその運転方法
JP5492178B2 (ja) * 2011-12-12 2014-05-14 株式会社東芝 可変磁束ドライブシステム
JP6410939B2 (ja) * 2015-07-10 2018-10-24 三菱電機株式会社 モータ制御装置、圧縮機、及び空気調和機

Similar Documents

Publication Publication Date Title
WO2005093943A1 (fr) Contrôleur de moteur synchrone à aimant permanent
KR20030027933A (ko) 인버터장치 및 그 전류제어방법
JP3684793B2 (ja) インバータ装置
JP5412820B2 (ja) 交流電動機の制御装置及び制御方法
JP6449129B2 (ja) 電力変換装置
JP5392532B2 (ja) 誘導電動機の制御装置
JP5564828B2 (ja) 交流電動機の制御装置
WO2019106727A1 (fr) Procédé et dispositif de commande de machine électrique
WO2024106339A1 (fr) Convertisseur de puissance et procédé de commande de convertisseur de puissance
JP4437629B2 (ja) 電気車制御装置
JP5556054B2 (ja) 交流電動機の制御装置
JP4256238B2 (ja) 電力変換装置
JP2019205238A (ja) インバータ
JP2006006038A (ja) 電力変換装置
JP2000312497A (ja) 交流電動機の制御方法
JP7009861B2 (ja) モータ制御装置
JP5307578B2 (ja) 電動機制御装置
JP2021125900A (ja) モータ制御装置
JP3156427B2 (ja) Ｐｗｍインバータの電流制御装置
JP7154343B1 (ja) 回転機制御装置
JP7468669B2 (ja) 電動機の制御方法及び制御装置
JP7127657B2 (ja) モータ制御装置
JP6984672B2 (ja) モータ制御装置
US12126284B2 (en) Electric motor control method and electric motor system
JP7416166B1 (ja) モータ制御装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23891487

Country of ref document: EP

Kind code of ref document: A1