JP4935115B2 - Switched reluctance motor control device and control method thereof - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switched reluctance motor control apparatus and control method thereof, and more particularly to control of a switched reluctance motor in which U-phase, V-phase, and W-phase windings are independently connected to an inverter. The present invention relates to an apparatus and a control method thereof.

Conventionally, as a method for controlling a switched reluctance motor, one described in p53-70 of “Switched Reluctance Motors and their Control” (see Non-Patent Document 1) is known.
In this switched reluctance motor current control method, the energization start angle and energization end angle are determined for each phase with respect to the rotor angle, and the current upper limit command value and the current lower limit command value of the winding current are determined. ing.
When the rotor reaches the energization start angle, a positive voltage is applied to the winding, and the voltage application is stopped or a negative voltage is applied when the measured value of the winding current exceeds the current upper limit command value. Subsequently, when the measured value of the winding current becomes equal to or less than the current lower limit command value, a positive voltage is applied to the winding again.

In this way, the winding current is controlled to fall within the hysteresis width (current upper limit command value−current lower limit command value).
Japanese Patent Laid-Open No. 9-322581 “Switched Reluctance Motors and their Control” (TJE MILLER; MAGNA PHYSICS PUBLISHING OXFORD SCIENCE PUBLICATIONS)

  However, the number of current sensors required for current control of such windings flows in one phase when the windings are Y-connected or Δ-connected as in a general three-phase permanent magnet synchronous motor. Since the current passes through the other phase, it is possible to detect the current of all phases if there is a current sensor that is one less than the number of phases. However, a switched reluctance motor has independent windings for each phase. Therefore, in the conventional control device, the same number of current sensors as the number of phases are installed in order to detect the current of all phases. Therefore, it is inevitable that the cost of the current sensor is higher than that of the permanent magnet type synchronous motor.

In addition, for example, a “current detection method for a switched reluctance motor” (see Patent Document 1) is proposed, which has a configuration in which the winding current of all phases of a switched reluctance motor is detected by a single current sensor. However, when two or more phases are energized at the same time, only the total value is detected, so the current flowing in each phase cannot be detected separately and current control is possible. There wasn't.
SUMMARY OF THE INVENTION An object of the present invention is to provide a switched reluctance motor control device and a control method thereof that can control current with only one current detection device regardless of the number of phases and can reduce the cost associated with the current detection device. Is to provide.

In order to achieve the above object, a switched reluctance motor control apparatus according to the present invention comprises a stator having a plurality of phases of windings and a rotor that is rotated relative to the stator. Based on the motor torque command value of the motor, a switching signal and a diode constitute a half-bridge circuit to generate an inverter drive signal that applies a rectangular wave voltage to the winding, and a DC power source that applies a DC voltage to the inverter In a switched reluctance motor control device that operates by switching a phase through which a current flows by applying a rectangular wave voltage to a winding, a detection value of an angle detection device that detects a relative angular position of the rotor with respect to the stator And based on a detection value of a current detection device that detects a current flowing through a connection line between the DC power source and the inverter And a command value generating means for generating a command value for controlling the current flowing through the winding, the detected value of the angle detection device, the rotational speed, the voltage application start angle, that is the voltage applied finish angle It is a feature.

According to the present invention, based on a motor torque command value of a switched reluctance motor including a stator provided with a plurality of phases of winding and a rotor that is rotated relative to the stator, the switching element and the diode A half-bridge circuit is configured to generate an inverter drive signal that applies a rectangular wave voltage to the winding, and a DC power source that applies a DC voltage to the inverter applies a rectangular wave voltage to the winding to switch the phase through which the current flows. The control device for the switched reluctance motor operated by the controller includes a command value generating means for detecting a detection value of the angle detection device for detecting a relative angular position of the rotor with respect to the stator and a connection line between the DC power source and the inverter. A command value for controlling the current flowing through the winding is generated based on the detection value of the current detection device that detects the flowing current . Here, the detected values of the angle detection device are a rotation speed, a voltage application start angle, and a voltage application end angle.

For this reason, current control is possible with only one current detection device regardless of the number of phases, and the cost associated with the current detection device can be reduced.
In addition, the switched reluctance motor control apparatus according to the present invention can be realized by the switched reluctance motor control apparatus.

The best mode for carrying out the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a circuit block diagram of a switched reluctance motor control apparatus according to a first embodiment of the present invention. As shown in FIG. 1, an SRM control device 10 that controls a switched reluctance motor (SRM) includes an inverter drive signal generation unit 11 and a current command value generation unit 12. The line current is controlled to fall within the hysteresis width (current upper limit command value−current lower limit command value). Here, a case where current is supplied for each phase will be described.

The SRM 13 includes a stator around which a three-phase winding of a U-phase winding 13a, a V-phase winding 13b, and a W-phase winding 13c is wound, and a rotor that is rotated relative to the stator. An SRM driving inverter 14 is connected to the winding.
The SRM drive inverter 14 includes a U-phase upper switching element 14a, a V-phase upper switching element 14b, a W-phase upper switching element 14c, a U-phase lower switching element 14d, a V-phase lower switching element 14e, a W-phase lower switching element 14f, U An upper phase diode 14g, a V phase upper diode 14h, a W phase upper diode 14i, a U phase lower diode 14j, a V phase lower diode 14k, and a W phase lower diode 14l are provided. That is, the SRM drive inverter 14 forms a half-bridge circuit from the switching element and the diode, and applies a rectangular wave voltage to each phase winding of the SRM 13.

The SRM drive inverter 14 is connected to a DC power supply 15 for applying a DC voltage to the SRM drive inverter 14 and a smoothing capacitor 16. Further, the SRM drive inverter 14 detects the voltage of the DC power supply 15 and detects a DC voltage detection value Vdc. Are connected to a DC voltage sensor 17 that outputs a DC current sensor 18 that detects a current flowing through a connection line between the smoothing capacitor 16 and the inverter 14 and outputs a DC current detection value Idc. Although only one DC current sensor 18 is shown in the figure, it may be provided redundantly (for example, two) as a spare for failure. Further, the SRM 13 has a rotor angle of the SRM 13, that is, a rotation. A rotor angle sensor 19 that detects a relative angular position of the child with respect to the stator and outputs an angle detection value θ is connected.

The inverter drive signal generation unit 11 receives the rotor angle θ, the energization start angle command value θon *, the energization end angle command value θoff *, the current peak command value ip *, and the current hysteresis width command value ihys *, respectively. Output a signal. The output inverter drive signals are the U-phase upper switching element 14a, the V-phase upper switching element 14b, the W-phase upper switching element 14c, the U-phase lower switching element 14d, the V-phase lower switching element 14e, and the W-phase lower switching element 14f. Input to each base.
The current command value generation unit 12 receives the DC voltage detection value Vdc, the DC current detection value Id, the rotor angle θ, and the torque command value T *, respectively, and the energization start angle command value θon * and the energization end angle command value θoff *. , Current peak command value ip * and current hysteresis width command value ihys * are output.

Next, the operation of the SRM control device 10 having the above configuration will be described.
The SRM control device 10 receives a torque command value T * output from an external system (not shown), and a current waveform for energizing the windings of the SRM 13 so that the torque output from the SRM 13 matches the torque command value T *. To control.
FIG. 2 is an explanatory diagram showing a current waveform in a graph during operation of the SRM control device of FIG. FIG. 2 shows an example of a U-phase winding current waveform a and a DC current detection value (Idc) waveform b during current control.

As shown in FIG. 2, when the rotor angle θ reaches the energization start angle command value θon *, the U-phase upper switching element 14a and the U-phase lower switching element 14d are simultaneously turned on, and the U-phase winding current increases. When the U-phase winding current reaches the current peak command value ip *, the U-phase upper switching element 14a and the U-phase lower switching element 14d are simultaneously turned off, and the U-phase winding current decreases.
Thereafter, when the U-phase winding current decreases from the current peak command value ip * by the current hysteresis width command value ihys *, the U-phase upper stage switching element 14a and the U-phase lower stage switching element 14d are simultaneously turned on again. Line current increases. This is repeated until the rotor angle θ reaches the energization end angle command value θoff *, and thereafter, the U-phase upper switching element 14a and the U-phase lower switching element 14d are turned off. This reduces the current to zero.

The same operation is performed for the V phase and the W phase, but the energization start angle command value θon * and the energization end angle command value θoff * are delayed by 120 ° and 240 ° in electrical angle with respect to the U phase, respectively.
A method of simultaneously turning on / off the upper and lower switching elements and controlling the winding current to a constant value within the hysteresis width ihys * is called hard chop type hysteresis current control.

In other words, each phase includes an upper switching element connected to the positive terminal of the DC power supply 15 and a lower switching element connected to the negative terminal of the DC power supply 15. A hard chopping operation is performed which includes a state where both elements are turned on and a positive voltage is applied to the winding, and a state where both the upper switching element and the lower switching element are turned off and a negative voltage is applied to the winding.
As shown in FIG. 2, the DC current detection value Idc at this time is the same value as the U-phase winding current when the upper and lower switching elements are on, and the U-phase winding when the upper and lower switching elements are off. The value is obtained by inverting the sign of the current.

  That is, the U-phase winding current can be controlled by using the DC current detection value Idc as it is when the upper and lower switching elements are on, and by using -Idc when the upper and lower switching elements are off. It becomes possible. The V-phase winding current and the W-phase winding current can be controlled by the same method. When there is no period in which a plurality of phases are energized, the magnitude of the DC current detection value becomes the winding current value of each phase as it is as in the present embodiment.

  As described above, the control device 10 of the SRM including the above-described components generates a drive signal for the inverter 14 based on the motor torque command value T *, and applies a rectangular wave voltage to each phase winding to generate a current. The SRM 13 is operated by switching the phase to flow. Then, based on the detected value of the rotor angle sensor 19 which is an angle detection device and the detected current value detected from the connection line between the DC power supply 15 and the inverter 14 by the DC current sensor 18 which is a current detection device during operation. The winding current is controlled.

(Second Embodiment)
In the first embodiment, the case where there is no period in which a plurality of phases are energized has been described. However, in the second embodiment, when energizing simultaneously in a plurality of phases, for example, a period in which two phases are energized. A current control method in the case where the current exists will be described.
The SRM control device used in the second embodiment is the same as the SRM control device 10 of the first embodiment, and a description thereof will be omitted.

FIG. 3 is an explanatory diagram showing the U-phase current, the V-phase current, and the DC current sensor detection values in a graph when there is a period in which two phases are energized. As shown in FIG. 3, in the period A, only the U phase is energized, and in the period C, only the V phase is energized. The current control method in the periods A and C is as shown in the first embodiment. In the period B, the U phase and the V phase are energized, and the value of the winding current of each phase does not match the detected value of the DC current sensor.
Next, a method for calculating the winding current value of each phase in the period B will be described.

  First, the period B is classified into four patterns from pattern 1 to pattern 4. The conditions for switching to each pattern are as follows. In the following explanation, the state where the upper and lower switching elements are on is “on”, the state where they are off is “off”, the operation of switching from off to on is “turn on”, and from on The operation of switching off is called “turn-off”.

(Conditions for switching to pattern 1) When one phase is turned on and the other phase is turned on. (Conditions for switching to pattern 2) When one phase is turned on and the other phase is turned off. (Conditions for switching to pattern 3) When one phase is turned off and the other phase is turned on. (Conditions for switching to pattern 4) When one phase is off and the other phase is turned off.
Next, a method for calculating the winding current value of each phase in each pattern will be described.

(Pattern 1)
If the on-state phase is the X phase and the turn-on phase is the Y phase, the DC current detection value Idc after the turn-on is the sum (ix + ii) of the X-phase current ix and the Y-phase current iy. In addition, since the detected DC current value before turn-on is (ix−iy), the difference between the detected DC current value immediately after the turn-on and immediately before is 2ii.

（ｖ：直流電圧、Ｒ：巻線抵抗、ω：回転子角速度、Ｉ０：ｔ＝０における巻線電流、Ｌ：巻線インダクタンス、θ：回転子角度、ｔ：時間） Further, the winding current i of the SRM is generally expressed by the formula (1).

(V: DC voltage, R: winding resistance, ω: rotor angular velocity, I0: winding current at t = 0, L: winding inductance, θ: rotor angle, t: time)

The DC voltage v is the power supply voltage Vdc. ω is calculated by time differentiation of the rotor angle θ. Since the winding inductance L changes according to the rotor angle and the winding current, it is defined as a map using the rotor angle and the winding current as parameters, or an approximation using the rotor angle and the winding current as variables. It is determined by a method such as defining an expression. Since the winding resistance R actually changes depending on the winding temperature, the value is changed according to the winding temperature measured by a thermocouple or the like, or when the operating temperature range is narrow, the winding resistance R is determined as a constant value.
Here, when the time when the Y phase is turned on is t = 0, and (the difference between the DC current detection values immediately after the turn on and immediately before) ÷ 2 is I0, the Y phase winding current value in the pattern 1 can be calculated. . The X-phase winding current value ix is calculated by Idc-ii.

(Pattern 2)
If the on-state phase is the X phase and the turn-off phase is the Y phase, the DC current detection value Idc after the turn-off is the difference (ix-ii) between the X-phase current ix and the Y-phase current iy. Further, since the DC current detection value before turn-off is (ix + iy), the difference between the DC current detection value immediately after the turn-off and the previous DC current detection value is −2iy.
Here, the Y-phase winding current is calculated using Equation (1). The DC voltage v is -Vdc. ω, L, and R are determined by the same method as that for pattern 1. When the time when the Y phase is turned off is t = 0 and (difference between the DC current detection values immediately after the turn on and immediately before) − (− 2) is I0, the Y phase winding current value in the pattern 2 can be calculated. . The X-phase winding current value is calculated by Idc + iy.

(Pattern 3)
Assuming that the off-state phase is the X phase and the turn-on phase is the Y phase, the DC current detection value Idc after the turn-on is the difference (−ix + ii) between the y-phase current iy and the X-phase current ix. Also, since the DC current detection value before turn-on is (−ix−iy), the difference between the DC current detection value immediately after the turn-on and immediately before is 2iy.
Here, the Y-phase winding current is calculated using Equation (1). The DC voltage v is Vdc. ω, L, and R are determined by the same method as that for pattern 1. When the time at which the Y phase is turned on is t = 0 and (difference between the DC current detection values immediately after the turn on and immediately before) is divided by I0, the Y phase winding current value in the pattern 3 can be calculated. The X-phase winding current value is calculated by iy-Idc.

(Pattern 4)
When the off-state phase is the X phase and the turn-off phase is the Y phase, the DC current detection value Idc after the turn-off is (difference between the X phase current ix and the Y phase current iy) × (−1), that is, (−ix -Ii). Further, since the DC current detection value before turn-off is (−ix + iy), the difference between the DC current detection value immediately after the turn-off and the previous DC current detection value is −2iy.
Here, the Y-phase winding current is calculated using Equation (1). The DC voltage v is -Vdc. ω, L, and R are determined by the same method as that for pattern 1. When the time when the Y phase is turned off is t = 0 and (difference between the DC current detection values immediately after the turn on and immediately before) − (− 2) is I0, the Y phase winding current value in the pattern 2 can be calculated. . The X-phase winding current value is calculated by -iy-Idc.

FIG. 4 is an explanatory diagram showing the pattern classification of the hard chop type period B as a table.
As described above, by using the expression (1), the instantaneous winding current at any time of each phase in the period B can be calculated. In addition, since the Y-phase current value can be directly calculated from the DC current detection value without using the current equation each time the turn-on and turn-off are performed, the current value can be separated with high accuracy.
Further, the formula (1) is calculated in advance, and the winding current is determined as a DC current detection value, a DC voltage value, a turn-on angle, a turn-off angle, an elapsed time from the turn-on, and an elapsed time from the turn-off. The map can be stored as a map corresponding to any one or more of the rotor speed, the winding resistance, and the winding inductance. By mapping, it is possible to calculate the current value even with an inexpensive arithmetic device that is difficult to calculate the exponential function.

Further, in both the first embodiment and the second embodiment, the hard chop type hysteresis current control has been described as an example, but one of the upper and lower switching elements is kept on and the other is turned on / off. The present invention is also applicable to soft chop type hysteresis current control that performs current control.
The difference between the soft chop type and the hard chop type is that there is a pattern in which one of the upper and lower switching elements is in the on state and the other is in the off state. In this pattern, since the winding current flows back through the diode and does not flow to the DC power source, the DC current detection value is zero. Accordingly, 12 types of pattern classification are added to the four types of hard chop type, for a total of 16 types, but the current value can be calculated by a method similar to the method shown in the present embodiment.

FIG. 5 is an explanatory diagram showing the pattern classification of the period B added in the soft chop type as a table.
Further, in the present embodiment, the pattern switching is performed for each phase, but the current values can be separated even if the two phases simultaneously perform pattern switching. In that case, since the current value is not separated even if the difference between the current values before and after the pattern switching is taken, the current value of the equation (1) is continuously calculated to separate and estimate the current value for each phase. .

  In both the first embodiment and the second embodiment, the DC current sensor 18 is installed between the smoothing capacitor 16 and the inverter 14, but the installation location is not limited to this. For example, by arranging one current sensor so as to cover the positive side of the DC power supply 15 and the positive side of the smoothing capacitor 16, a current waveform similar to that in the first embodiment and the second embodiment is observed. It becomes possible. This is an effective installation method when the smoothing capacitor 16 and the inverter 14 are arranged close to each other in order to reduce the parasitic inductance of the wiring, and a space for installing the DC current sensor 18 cannot be secured sufficiently.

(Third embodiment)
The third embodiment is characterized in that an estimated value of the U-phase winding current obtained from the current equation is compared with a DC current detection value to detect an abnormality in the U-phase winding.
FIG. 6 is a flowchart showing a flow of processing for detecting an abnormality of the U-phase winding.
The abnormality detection process for the U-phase winding is started immediately after the U-phase switching element is turned on or turned off. The time when the U-phase switching element is turned on or turned off is defined as 0.

As shown in FIG. 6, first, when the abnormality detection process is started, as described in the first embodiment and the second embodiment, the time 0 (t = 0) is used using the current equation (1). ) To calculate the U-phase winding current estimated value iu _est (step S101).
Next, the U-phase winding current iu is detected from the difference between the DC current detection values around time 0 (step S102).
Next, | U-phase winding current iu−U-phase winding current estimated value iu _est | is calculated, and it is determined whether the value is smaller than winding current abnormality threshold Ierr (| iu-iu _est | ≧ Ierr). (Step S103). As a result of the determination, if it is not smaller than the winding current abnormality threshold Ierr (yes), the abnormality detection flag is turned on (step S104), and if it is smaller than the winding current abnormality threshold Ierr (no), the abnormality detection flag is not turned on. Exit.

Up to this point, the abnormality detection process for only the U phase has been described, but the same process is performed for all phases.
When the abnormality detection flag is turned on, the energization start angle command value θon * and the energization end angle command value θoff * are limited so that two or more phases are not energized at the same time in the subsequent operation. Also, the switching method is limited to the hard chop type. By providing such a restriction, each phase winding current can be detected directly from the DC current detection value without using the current equation. Therefore, even when the motor constant has changed extremely with respect to the design value due to a failure such as a short circuit of the winding, the winding current can be accurately grasped, and a reliable abnormality detection process can be performed.

Further, the start timing of the abnormality detection process is not limited to immediately after the U-phase switching element is turned on or turned off, and may be implemented at regular intervals, for example. In addition, since patterns 1, 2, 3, 4, 5, 7, 9, 11, 13, and 15 perform current estimation using a current equation until immediately before the start of the pattern, abnormality detection is performed only immediately after the start of these patterns. If the processing is performed, calculation of the U-phase winding current estimated value iu _est at time 0 (t = 0) using the current equation (1) (step S101) can be omitted, and the calculation load is reduced. be able to.

As described above, the switched reluctance motor control apparatus according to the present invention is a switched reluctance motor including a stator having a plurality of phases of windings and a rotor that is rotated relative to the stator. Based on the motor torque command value, a switching element and a diode constitute a half-bridge circuit to generate an inverter drive signal that applies a rectangular wave voltage to the winding, and a DC power source that applies a DC voltage to the inverter In a switched reluctance motor control device that operates by switching a phase through which a current is applied by applying a rectangular wave voltage to the detection value of an angle detection device that detects a relative angular position of the rotor with respect to the stator; based on the detected value of the current detector for detecting current flowing in the connecting line between the DC power supply and the inverter, the winding And a command value generating means for generating a command value for controlling the current flowing in the detection value of the angle detection device is characterized in that the rotational speed, the voltage application start angle, a voltage application end angle .

As a result, current control can be performed with only one current detection device regardless of the number of phases, so that the cost of the current detection device can be reduced. In particular, since the current of the connecting line between the DC power supply and the inverter is detected, even when two or more phases are energized, it is easy to separate and detect the current flowing in each phase. Current control is also possible.
The switched reluctance motor control device according to the present invention includes a detection value of the current detection device, a DC voltage value, a rotation speed of the rotor, a voltage application start angle, and a voltage application end angle. Based on the above , the current flowing through the winding is calculated.

Thus, in the operation state simultaneously energizing a plurality of windings, and the detection value of the current detection device, and the rotational speed of the rotor, and a voltage application start angle, based on the voltage application end angle, the current flowing through the winding Therefore, even in an operating state in which a plurality of phases are energized simultaneously, it is possible to control the currents of all phases. Also, if you are performing current control by so-called soft chopping, by turning off the one of the upper and lower switching elements, there is the possibility of returning a current flowing in the winding through a diode, the winding in this case the current detection device Although the current flowing through the line is no longer detected, it becomes possible to calculate the current flowing through the winding at reflux.

Further, in the switched reluctance motor control device according to the present invention, the switching element includes an upper switching element connected to a positive terminal of the DC power supply and a lower stage connected to a negative terminal of the DC power supply. A switching element is provided for each phase, and both the upper and lower switching elements of one phase are turned on and a positive voltage is applied to the winding, and both the upper and lower switching elements are turned off. In a hard chopping operation including a state in which a negative voltage is applied to the winding, a difference between a detection value of the current detection device immediately before the state is switched from one to the other and a detection value of the current detection device immediately after the switching is performed. based on, and calculates a current flowing through the winding at the time the state is switched.

As a result, both the upper switching element and the lower switching element of one phase are turned on and a positive voltage is applied to the winding, and the negative voltage is applied to the winding by turning off both the upper switching element and the lower switching element. In the operation state including the state 2 for applying the state, the state is switched based on the difference between the detection value of the current detection device immediately before the state is switched from one to the other and the detection value of the current detection device immediately after the switching. since calculating the current flowing through the winding at the time, even if at the same time energizing the plurality of phases if the performing current control by a so-called hard chopping, can be detected by separating the phases of the current .

Further, in the switched reluctance motor control device according to the present invention, the switching element includes an upper switching element connected to a positive terminal of the DC power supply and a lower stage connected to a negative terminal of the DC power supply. A switching element is provided for each phase, and both the upper and lower switching elements of one phase are turned on and a positive voltage is applied to the winding, and both the upper and lower switching elements are turned off. In a soft chopping operation including a state in which a negative voltage is applied to the winding and a state in which one of the upper switching element and the lower switching element is on and the other is off, from any state to another state Based on the difference between the detection value of the current detection device immediately before switching and the detection value of the current detection device immediately after switching. Te, and calculates a current flowing through the winding at the time the state is switched.

As a result, in the operating state including the state 1, the state 2, and the state 3 in which one of the upper switching element and the lower switching element is on and the other is off, from any state to another state a detection value immediately before the current detecting device is switched, based on the difference between the detected value of the current detecting device immediately after switching, so calculating the current flowing through the winding at the time the state is switched, so-called soft chopping Even when a plurality of phases are energized at the same time when the current control is performed by this, the current of each phase can be separated and detected.

The control device of the switched reluctance motor according to the present invention, a method of calculating the current flowing through the windings, if the switching state occur simultaneously in a plurality of phases only, a detection value of the current detecting device The method is changed to a calculation method based on the DC voltage value, the rotation speed of the rotor, the voltage application start angle, and the voltage application end angle.
Thus, when a plurality of phase states are switched at the same time, can not be detected by separating the phases of the current and calculate the difference between the detected current value immediately before and immediately after the state switching, flowing through the windings The calculation method of the current is only when the state switching occurs simultaneously in a plurality of phases, the detection value of the current detection device, the DC voltage value, the rotation speed of the rotor, the voltage application start angle, and the voltage application end angle. It becomes possible to isolate | separate the electric current of each phase by changing to the method calculated based on.

In the switched reluctance motor control device according to the present invention , the current flowing through the winding to be calculated includes a detection value of the current detection device, a voltage application start angle, a DC voltage value, and a voltage application end. Stored as a map corresponding to at least one of the angle, the elapsed time from the voltage application start timing, the elapsed time from the voltage application end timing, the rotor speed, the winding resistance, and the winding inductance It is characterized by being.
Thus, the current flowing in the windings the calculation, the detection value of the current detecting device, a DC voltage value, the voltage application start angle, and the voltage application end angle, and the elapsed time from the voltage application start time, Since it is stored as a map corresponding to any one or more of the elapsed time from the voltage application end timing, the rotor speed, the winding resistance, and the winding inductance, the amount of calculation required for calculating the current is reduced. can do.

Further, the switched reluctance motor control device according to the present invention detects a U-phase winding current from a difference in DC current detection value at a predetermined time, and detects the U-phase winding current from the U-phase winding current. Calculate the absolute value minus the estimated current value, determine whether the value is smaller than the winding current abnormality threshold, and after detecting the winding current abnormality from the judgment result , the state where multiple phases are energized Therefore, the voltage application start angle and the voltage application end angle are limited, and the switching element of the inverter is limited only to a hard chopping operation.

Thus , the U-phase winding current is detected from the difference in the DC current detection value at a predetermined time, and the absolute value obtained by subtracting the estimated U-phase winding current value from the U-phase winding current is calculated. Is determined to be less than the winding current abnormality threshold value, and it is determined that a system abnormality has occurred when a winding current abnormality is detected from the determination result, so that an abnormality such as a short circuit in the winding can be detected quickly. . After determining that a system abnormality has occurred, the voltage application start angle and the voltage application end angle are limited so that a state in which a plurality of phases are energized does not occur, and the driving method of the inverter switching element is only hard chopping. Therefore, without using the current equation, the winding current value of each phase can be detected directly from the value of the DC current detection device. Therefore, an abnormality such as a short circuit occurs in the winding, and the motor constant becomes large as the set value. Current control is possible even in different situations.

The switched reluctance motor control method according to the present invention is a motor torque of a switched reluctance motor comprising a stator having a plurality of phases of windings and a rotor that is rotated relative to the stator. Based on the command value, a switching element and a diode form a half-bridge circuit to generate an inverter drive signal that applies a rectangular wave voltage to the winding, and a rectangular wave is applied to the winding by a DC power source that applies a DC voltage to the inverter. In the method of controlling a switched reluctance motor that operates by switching a phase in which a current is applied by applying a voltage, the switching element includes an upper switching element connected to a positive terminal of the DC power supply, and the DC power supply A lower switching element connected to the negative terminal for each phase, an upper switching element for one phase, and At the time of hard chopping operation including a state where both the stage switching elements are turned on and a positive voltage is applied to the winding, and a state where both the upper stage switching element and the lower stage switching element are turned off and a negative voltage is applied to the winding, Based on the difference between the detection value of the current detection device that detects the current flowing through the connection line between the DC power supply and the inverter immediately before the state is switched from one to the other, and the detection value of the current detection device immediately after the switching. Te to calculate the current flowing through the winding at the time the state is switched, based on the detected value of the angle detection device for detecting the relative angular position relative to the stator of the rotor, the detection value of the current detecting device Te, generates a command value for controlling the current flowing through the winding, the detected value of the angle detection device, the rotational speed, the voltage application start angle, voltage application end angle Characterized in that there.

The switched reluctance motor control method according to the present invention is a motor torque of a switched reluctance motor comprising a stator having a plurality of phases of windings and a rotor that is rotated relative to the stator. Based on the command value, a switching element and a diode form a half-bridge circuit to generate an inverter drive signal that applies a rectangular wave voltage to the winding, and a rectangular wave is applied to the winding by a DC power source that applies a DC voltage to the inverter. In the method of controlling a switched reluctance motor that operates by switching a phase in which a current is applied by applying a voltage, the switching element includes an upper switching element connected to a positive terminal of the DC power supply, and the DC power supply A lower switching element connected to the negative terminal for each phase, an upper switching element for one phase, and The state where both the stage switching elements are turned on and a positive voltage is applied to the winding, the state where both the upper stage switching element and the lower stage switching element are turned off and the negative voltage is applied to the winding, the upper stage switching element and the lower stage switching Current flowing through the connection line between the DC power supply and the inverter immediately before switching from any state to another state during soft chopping operation including a state where either one of the elements is on and the other is off a detection value of a current detector for detecting, based on a difference between the detected value of the current detecting device immediately after switching, to calculate the current flowing through the winding at the time the state is switched, the said rotor the detected value of the angle detection device for detecting the relative angular position with respect to the stator, based on the detected value of the current detecting device, control the current flowing through the winding Generates a command value for the detection value of the angle detection device, the rotational speed, the voltage application start angle, characterized in that it is a voltage application end angle.

  Accordingly, it is possible to provide a control method for a switched reluctance motor that can control current with only one current detection device regardless of the number of phases and can reduce the cost of the current detection device.

Thus, according to the present invention, switching is performed based on a motor torque command value of a switched reluctance motor including a stator provided with a plurality of phases of winding and a rotor that is rotated relative to the stator. A half-bridge circuit is composed of elements and diodes, and a drive signal for an inverter that applies a rectangular wave voltage to the winding is generated. A rectangular wave voltage is applied to the winding by a DC power source that applies a DC voltage to the inverter, and a current is generated. In a switched reluctance motor control device that operates by switching a flowing phase, a detection value of an angle detection device that detects a relative angular position of the rotor with respect to the stator, and a connection between the DC power source and the inverter based on the detected value of the current detector for detecting current flowing through the line, and generates a command value for controlling the current flowing through the winding Comprising a decree value generating means, a detection value of the angle detection device, the rotational speed, the voltage application start angle, since voltage application end angle, a current detecting device only allows current control regardless of the number of phases Thus, the cost associated with the current detection device can be reduced.
In addition, the switched reluctance motor control apparatus according to the present invention can be realized by the switched reluctance motor control apparatus.

1 is a circuit block diagram of a switched reluctance motor control apparatus according to a first embodiment of the present invention. FIG. It is explanatory drawing which shows the current waveform at the time of operation | movement of the SRM control apparatus of FIG. 1 with a graph. It is explanatory drawing which shows the U-phase electric current, V-phase electric current, and DC current sensor detection value with a graph in the case where the period which supplies with electricity to two phases exists. It is explanatory drawing which showed the pattern classification of the hard chop type period B as a table | surface. It is explanatory drawing which showed the pattern classification | category of the period B added in a soft chop type | mold as a table | surface. It is a flowchart which shows the flow of the process which detects abnormality of a U-phase winding.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 SRM control apparatus 11 Inverter drive signal generation part 12 Current command value generation part 13 SRM
13a U-phase winding 13b V-phase winding 13c W-phase winding 14 SRM drive inverter 14a U-phase upper switching element 14b V-phase upper switching element 14c W-phase upper switching element 14d U-phase lower switching element 14e V-phase lower switching element 14f W-phase lower switching element 14g U-phase upper diode 14h V-phase upper diode 14i W-phase upper diode 14j U-phase lower diode 14k V-phase lower diode 14l W-phase lower diode 15 DC power supply 16 Smoothing capacitor 17 DC voltage sensor 18 DC current sensor 19 Rotor angle sensor a U-phase winding current waveform b DC current detection value waveform

Claims (9)

Based on the motor torque command value of a switched reluctance motor equipped with a stator with a multi-phase winding and a rotor that is rotated relative to the stator, a half-bridge circuit is composed of a switching element and a diode. Generates a drive signal for an inverter that applies a rectangular wave voltage to the winding, applies a rectangular wave voltage to the winding by a DC power source that applies a DC voltage to the inverter, and switches the phase in which the current flows. In the reluctance motor control device,
The detected value of the angle detection device for detecting the relative angular position relative to the stator of the rotor, based on the detected value of the current detector for detecting current flowing in the connecting line between the DC power supply and the inverter, the Command value generating means for generating a command value for controlling the current flowing in the winding , and
The control value of the switched reluctance motor, wherein the detected values of the angle detection device are a rotation speed, a voltage application start angle, and a voltage application end angle . A detection value of the current detection device, a DC voltage value, the rotational speed of the rotor, and wherein the voltage application start angle, on the basis of the voltage application end angle, to calculate a current flowing through the winding The switched reluctance motor control device according to claim 1. The switching element includes an upper switching element connected to the positive terminal of the DC power supply and a lower switching element connected to the negative terminal of the DC power supply for each phase.
A state where both the upper switching element and the lower switching element of one phase are turned on and a positive voltage is applied to the winding, and a state where both the upper switching element and the lower switching element are turned off and a negative voltage is applied to the winding In a hard chopping operation comprising: the detection value of the current detection device immediately before the state changes from one to the other, and the difference between the detection value of the current detection device immediately after the change, at the time when the state changes 3. The switched reluctance motor control apparatus according to claim 1, wherein a current flowing through the winding is calculated. The switching element includes an upper switching element connected to the positive terminal of the DC power supply and a lower switching element connected to the negative terminal of the DC power supply for each phase.
A state where both the upper switching element and the lower switching element of one phase are turned on and a positive voltage is applied to the winding, and a state where both the upper switching element and the lower switching element are turned off and a negative voltage is applied to the winding And a detected value of the current detection device immediately before switching from any state to another state in a soft chopping operation in which one of the upper switching element and the lower switching element is on and the other is off 3. The switched current according to claim 1, wherein a current flowing through the winding at the time of switching is calculated based on a difference between detection values of the current detection device immediately after switching.・ Reluctance motor controller. The method of calculating the current flowing through the windings, if the switching state occur simultaneously in a plurality of phases only, a detection value of the current detection device, a DC voltage value, the rotational speed of the rotor, the voltage application start 5. The switched reluctance motor control device according to claim 3, wherein the control method is changed to a method of calculating based on the angle and the voltage application end angle. Current flowing through the winding of calculating the detected value of the current detection device, and the voltage application start angle, a DC voltage value, the voltage application end angle, and the elapsed time from the voltage application start time, the voltage application end timing 5. A map corresponding to any one or more of the elapsed time from the rotor, the rotor speed, the winding resistance, and the winding inductance is stored. Switched reluctance motor control device according to the item. The U-phase winding current is detected from the difference in the DC current detection value at a predetermined time, and the absolute value obtained by subtracting the estimated value of the U-phase winding current from the U-phase winding current is calculated. After determining whether the current is less than the current abnormality threshold and detecting the winding current abnormality from the determination result , the voltage application start angle and the voltage application end angle are limited so that a state where a plurality of phases are not energized occurs. The switching device of the switched reluctance motor according to claim 6, wherein the switching element of the inverter is limited to a hard chopping operation only. Based on the motor torque command value of a switched reluctance motor equipped with a stator with a multi-phase winding and a rotor that is rotated relative to the stator, a half-bridge circuit is composed of a switching element and a diode. Generates a drive signal for an inverter that applies a rectangular wave voltage to the winding, applies a rectangular wave voltage to the winding by a DC power source that applies a DC voltage to the inverter, and switches the phase in which the current flows. In the reluctance motor control method,
The switching element includes an upper switching element connected to a positive terminal of the DC power supply and a lower switching element connected to a negative terminal of the DC power supply in each phase, and an upper switching element of one phase. In a hard chopping operation in which both the lower switching element is turned on and a positive voltage is applied to the winding, and the upper switching element and the lower switching element are both turned off and a negative voltage is applied to the winding. The difference between the detection value of the current detection device that detects the current flowing through the connection line between the DC power supply and the inverter immediately before the state is switched from one to the other, and the detection value of the current detection device immediately after the switching. based on, to calculate the current flowing through the winding at the time the state is switched,
The detected value of the angle detection device for detecting the relative angular position relative to the stator of the rotor, based on the detected value of the current detector, and generates a command value for controlling the current flowing through the winding,
The control value of the switched reluctance motor, wherein the detected values of the angle detection device are a rotation speed, a voltage application start angle, and a voltage application end angle . Based on the motor torque command value of a switched reluctance motor equipped with a stator with a multi-phase winding and a rotor that is rotated relative to the stator, a half-bridge circuit is composed of a switching element and a diode. Generates a drive signal for an inverter that applies a rectangular wave voltage to the winding, applies a rectangular wave voltage to the winding by a DC power source that applies a DC voltage to the inverter, and switches the phase in which the current flows. In the reluctance motor control method,
The switching element includes an upper switching element connected to a positive terminal of the DC power supply and a lower switching element connected to a negative terminal of the DC power supply in each phase, and an upper switching element of one phase. And a state where both the lower switching element is turned on and a positive voltage is applied to the winding, a state where both the upper switching element and the lower switching element are turned off and a negative voltage is applied to the winding, an upper switching element and the lower stage During soft chopping operation including a state in which either one of the switching elements is on and the other is off, it flows through a connection line between the DC power supply and the inverter immediately before switching from any state to another state Based on the difference between the detection value of the current detection device that detects the current and the detection value of the current detection device immediately after switching, the state is The current flowing through the winding is calculated at the time the unusual Ri,
The detected value of the angle detection device for detecting the relative angular position relative to the stator of the rotor, based on the detected value of the current detector, and generates a command value for controlling the current flowing through the winding,
The control value of the switched reluctance motor, wherein the detected values of the angle detection device are a rotation speed, a voltage application start angle, and a voltage application end angle .

Images