JP4592712B2 - Motor control device - Google Patents

Description

  The present invention relates to a motor control device that controls driving of a motor by using an inverter circuit, and in particular, controls the deceleration and stop of an inverter device that performs sudden variable speed control on the motor and a motor driving device that rotates the motor by external force. The present invention relates to a motor control device suitable for performing.

  In recent years, motor drive devices have become inverters, and most home electric appliances are inverter control devices using brushless motors.

  Among them, the washing machine frequently repeats rapid deceleration operations such as repeated rotation, stop, (reversal), and sudden stop from high-speed rotation during dehydration. In addition, it is necessary to suppress (decelerate) the number of revolutions of a system such as an electric bicycle or a fan that is rotated by an external force so as not to be overspeeded.

  In order to perform such deceleration and stop, for example, a mechanical brake device is installed on the motor shaft, or an electric current is passed so as to generate a brake torque on the drive motor, so that it can be used as an electromagnetic brake (electric brake device). Or a combination of the above two brakes is known.

  For example, a control device for a washing tub drive motor of a washing machine is known as shown in FIG. In this control device, a power consumption circuit 11 that consumes regenerative energy is provided in a stage preceding the inverter main circuit 1, and a mechanical brake device 12 is provided on the motor shaft. However, the mechanical brake device 12 literally has a separate mechanical mechanism, and it is difficult to reduce the size and weight.

  Further, as a method of using the drive motor as the electric brake device, there are a method of short-circuiting the windings of the drive motor and a method of flowing a current having a phase opposite to the induced voltage (referred to as an anti-phase current method).

  As methods for short-circuiting the motor windings, for example, those described in Patent Literature 1 and Patent Literature 2 have been proposed, but none of these methods has sufficient braking force.

  On the other hand, in the reverse phase current method, the brake torque can be applied to the motor by flowing a current in the opposite phase to the induced voltage, but at this time, regenerative energy is generated, and this regenerative energy increases the DC voltage on the inverter input side. Resulting in. For this reason, it is necessary to install the power consumption circuit 11 for consuming regenerative energy.

  In order to prevent the DC voltage from rising without using the power consuming circuit 11 or the like, a method of slowing down by reducing the deceleration rate is conceivable. However, this method cannot achieve the sudden deceleration that is the original purpose.

  Therefore, as one method for solving these problems, for example, a method described in Patent Document 3 has been proposed. This method is an improvement over the above-described anti-phase current method, in which the DC voltage is maintained at a set value by adjusting the phase of the winding current according to the magnitude of the DC voltage, and the power consumption circuit 11 is omitted. It is.

  In this method, when a brake start command is generated, the phase and voltage value of the inverter output voltage are initially set to a preset value (value relative to the rotation speed) and output according to the rotation speed at that time. Thereafter, the phase and voltage value of the inverter output voltage are adjusted according to the magnitude of the DC voltage value or the rate of decrease in the rotational speed. Here, the phase and the voltage value may be changed separately or linked.

  When the phase and voltage value of the output voltage of the inverter are changed, the phase and magnitude of the winding current of the motor change, and the regenerative energy and brake torque can be changed. For this reason, according to the said system, since regenerative energy can be adjusted, it becomes possible to suppress a raise of DC voltage and to adjust DC voltage to a fixed value.

Japanese Patent Laid-Open No. 10-323079 JP 2000-134905 A Japanese Patent Laid-Open No. 11-275889

  However, in the above prior art, when the regenerative energy is changed, the break torque also changes at the same time. Therefore, the regenerative energy cannot be adjusted while controlling the brake torque to a predetermined value. In other words, since the break torque and the regenerative energy cannot be individually controlled, it is difficult to decelerate while controlling the rotation speed to a predetermined value.

  In addition, the relationship between the phase and magnitude (voltage value) of the inverter output voltage, regenerative energy, and brake torque is insufficient. In other words, there is no theoretical explanation for the method of determining the phase and magnitude (voltage value) of the inverter output voltage, and it is determined experimentally, so it becomes difficult to respond depending on the variation of the drive motor or the difference in the model. .

  Furthermore, although the DC voltage is controlled by adjusting the regenerative energy, there is no idea of reducing the regenerative energy to zero, in other words, equalizing the input / output power of the motor and suppressing the increase in DC voltage.

  The problem to be solved by the present invention is that the motor is controlled in a state in which the increase of the DC voltage is suppressed while controlling the brake torque without using a device that applies braking force to the motor or a circuit that consumes electrical energy generated from the motor. An object of the present invention is to provide a motor control device capable of decelerating and stopping.

In order to solve the above problems, a first aspect of the present invention is connected to an inverter circuit having a DC power supply as input, a DC voltage detector for detecting a DC voltage of the inverter circuit, and an output of the inverter circuit. In the motor control device including a motor and speed detection means for detecting the speed of the motor, the inverter circuit controls the motor current of the motor by dividing it into a q-axis current and a d-axis current in a rotating coordinate system. control type inverter circuit der is, to control the braking torque by controlling the pre-Symbol q-axis current, it is configured to control the regenerative energy by controlling the d-axis current, and a deceleration of the motor the when the detected voltage of the DC voltage detector exceeds a predetermined value, the detected voltage to so that a d-axis current command a near zero power factor of the motor by the predetermined value Outputs, and controlling the d-axis current independently of the q-axis current.

The second aspect of the present invention includes an inverter circuit having a DC power supply as an input, a DC current detector for detecting a DC current of the inverter circuit , a motor connected to the output of the inverter circuit , and the motor In the motor control device comprising a speed detecting means for detecting the speed of the motor, the inverter circuit is a vector control type inverter circuit that controls the motor current of the motor by dividing it into a q-axis current and a d-axis current of a rotating coordinate system. Ah it is, to control the braking torque by controlling the pre-Symbol q-axis current, the by controlling the d-axis current is configured to control the regenerative energy, the deceleration time or the DC current detector of the motor when the detected current is negative, outputs to so that a d-axis current command value the detected current close to zero output current of the DC power supply to the predetermined value, the d-axis electric The flow is controlled independently of the q-axis current .

A third aspect of the present invention is a vector control type inverter circuit that can be controlled by dividing a q-axis current and a d-axis current of a rotating coordinate system using a DC power supply as an input, and connected to the output of the inverter circuit. And a speed detecting means for detecting the speed of the motor, wherein the inverter circuit calculates a q-axis current command value so that the speed of the motor becomes a predetermined value. when DC power, DC voltage, when at least one and a regenerative energy detection means for detecting, during deceleration of the motor or to the q-axis current command value of the DC current or the motor input power is negative, the be controlled independently of the q-axis current d-axis current as electric power regenerated to the DC power supply from the motor is close to zero by using the detection value from the regenerative energy detection means Characterized by comprising a regenerative energy control means.

  According to the present invention, when the motor is decelerated, the brake torque and the regenerative energy are controlled separately, or the power factor is reduced to keep the DC voltage or regenerative energy at a predetermined value. The speed of the motor can be controlled, and the motor is decelerated while controlling the brake torque without using a device that applies braking force to the motor or a circuit that consumes electrical energy generated from the motor, while suppressing an increase in DC voltage.・ Can be stopped.

  Further, when the motor is rotated by an external force, it is possible to prevent an increase in DC voltage, and a safe stop and deceleration operation can be performed.

  Furthermore, when the motor control device is used in a washing tub driving device of a washing machine, the mechanical brake device and the power consumption circuit can be consumed, so that the weight can be reduced.

  On the other hand, when the motor control device is applied to an electric vehicle, automatic braking control on a slope and charging of a battery are possible, and safety can be improved.

  Further, when the present invention is applied to an outdoor unit motor fan drive device for an air conditioner, an increase in DC voltage can be prevented even if the fan is rotated by wind.

  Furthermore, when the present invention is applied to a drive device for an electric vehicle, it can be used as an engine brake.

  As described above, according to the present invention, when the motor is decelerated, the DC voltage rises while controlling the brake torque without using a device that applies braking force to the motor or a circuit that consumes electrical energy generated from the motor. It becomes possible to decelerate and stop the motor in a state where the above is suppressed.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, as a brushless motor in the first embodiment and other embodiments, a cylindrical shape whose inductance does not change depending on the rotational position is shown as an example.

(First embodiment)
FIG. 1 is a block configuration diagram when the present invention is applied to a motor control device that controls driving of a brushless motor that drives a washing tub of a washing machine. In FIG. 1, the washing machine generally employs a method of rectifying a commercial AC power supply in order to obtain a DC power supply. In this embodiment, a similar circuit is provided and connected to the commercial AC power supply. 10 is used to obtain DC power. Here, a power factor correction circuit for improving the power factor can be installed on the output side of the rectifier circuit 10, or a circuit that directly generates DC power, such as a battery, can be connected.

  An inverter main circuit 1 as an inverter circuit is connected to the output side of the rectifier circuit 10, and a smoothing capacitor C is provided between the rectifier circuit 10 and the inverter main circuit 1. The inverter main circuit 1 includes, for example, a plurality of thyristors, GTOs, transistors, and the like as switching elements constituting the three-phase arm, and a diode is connected in parallel with each switching element. The inverter main circuit 1 takes in DC power from the rectifier circuit 10, converts this DC power into AC power in response to a control signal (PWM signal) from the control circuit 60, and converts the converted AC power into the brushless motor 2. To supply. A washing tub 3 is connected to the brushless motor 2, and the washing tub 3 is driven by the rotational drive of the brushless motor 2. In this embodiment, a control signal is given to the inverter main circuit 1 to control the conversion output (power conversion output) by the inverter main circuit 1, and the regenerative energy generated from the brushless motor 2 when the brushless motor 2 decelerates. And conversion output control means for separately controlling the brake torque acting on the brushless motor.

  This conversion output control means divides the motor current of the brushless motor 2 into a q-axis current (motor current component orthogonal to the magnetic flux) and a d-axis current (motor current component parallel to the magnetic flux) of the rotating coordinate system. Is adjusted to control brake torque, and d-axis current is adjusted to control regenerative energy.

  Specifically, the conversion output control means includes a DC voltage detector 7a, a DC voltage suppression circuit 7, a rotation speed control circuit 5, a control circuit 60, a rotation speed calculation circuit 4, and a position detector 4a. .

  The DC voltage detector 7a is configured as DC voltage detection means or regenerative energy detection means for detecting a DC voltage across the capacitor C as a DC voltage on the input side of the inverter main circuit 1. The detection voltage of the DC voltage detector 7a is The voltage is input to the DC voltage suppression circuit 7. The DC voltage suppression circuit 7 outputs 0 as the d-axis current command value id * at the time of constant speed and acceleration of the brushless motor 2, and when the brushless motor 2 is decelerated, the detected voltage of the DC voltage detector 7a is a predetermined value. When Ed1 * is exceeded, it is configured as d-axis current command value generating means for performing proportional-integral calculation on the DC voltage and outputting d-axis current command value Id *. The output of the d-axis current command value Id * by the generation of the DC voltage suppression circuit 7 is performed by the rotation speed command value N *, the rotation speed calculation value N, and the DC voltage detection value. That is, as will be described later, it is determined whether or not the vehicle is decelerating based on the deviation between the rotation speed command value N * and the rotation speed calculation value N, and only when the DC voltage exceeds a predetermined value Ed1 * during deceleration. Outputs d-axis current command value * obtained by proportional-integral calculation of voltage, and outputs 0 (d-axis command value * = 0) at other times, that is, at acceleration and constant speed. .

  In addition, although the d-axis current command value at the time of constant speed and acceleration is set to 0, in order to improve the motor efficiency like the brushless motor 2 is a salient pole type, when the d-axis current needs to flow, The d-axis current command value at constant speed and acceleration can be set to a value other than 0 and a considerable value.

  On the other hand, the position detector 4 a is configured by a position sensor using, for example, a Hall element, and detects position information as a rotation position of the brushless motor 2 and outputs the position information to the rotation speed calculation circuit 4. It has become. The rotation speed calculation circuit 4 calculates the rotation speed of the brushless motor 2 from the position information detected by the position detector 4 a and outputs the rotation speed calculation value N to the DC voltage suppression control circuit 7 and the rotation speed control circuit 5. It has become. That is, the position detector 4a and the rotational speed calculation circuit 4 are configured as speed detecting means for detecting the speed of the brushless motor 2.

  The rotation speed control circuit 5 proportionally integrates the deviation between the rotation speed command value N * and the rotation speed calculation value N, and the q-axis current command value Iq * for setting the detected value of the speed detection means to the rotation speed command value. That is, it is configured as q-axis current command value generating means for generating a q-axis current command value Iq * for suppressing the deviation between the rotation speed command value N * and the rotation speed calculation value N to zero.

  The control circuit 60 includes, for example, a current controller, a d, q / 3-phase AC coordinate converter, and the like, and divides the motor current of the brushless motor 2 into a d-axis component and a q-axis component of the rotational coordinate system, As a control signal for controlling the regenerative energy generated from the brushless motor 2 by adjusting the brake torque for the brushless motor 2 by adjusting the q-axis current and adjusting the d-axis current, for example, a PWM (pulse width modulation signal) signal It is comprised as a control signal generation means which produces | generates. A control signal (PWM signal) generated by the control circuit 60 is applied to the gate of each switching element of the inverter main circuit 1.

  In addition to using a sensor such as a Hall element as the position detector 4a, a method of estimating position information from information such as an induced voltage, a terminal voltage, and a motor current induced in the brushless motor 2 can be employed. Further, when the brushless motor 2 is operated as a synchronous motor, the rotational speed feedback may not be performed.

  In the present embodiment, open loop control is assumed in which the voltage applied to the brushless motor 2 is determined from each current command value using a motor model, but the motor current flowing in the winding of the brushless motor 2 is detected. It is also possible to perform current control in which the motor current is dq converted and the converted current matches the current command value.

  Further, all except the rectifier circuit 10 and the inverter main circuit 1 such as the control circuit 60 and the rotation speed control circuit 5 can be realized by software processing using a one-chip microcomputer or DSP (digital signal processor).

  Next, an output determination algorithm for determining the output of the d-axis current command value Id * of the DC voltage suppression circuit 7 will be described with reference to FIG.

  First, in step S1, the difference between the rotational speed calculation value N of the brushless motor 2 and the rotational speed command value N * is calculated, and it is determined from this calculated value whether or not the vehicle is decelerating. As normal control, 0 is output as the d-axis current command value.

  On the other hand, when the vehicle is decelerating, the process proceeds to step S2 to determine whether or not the DC voltage exceeds a predetermined value Ed1 *. Here, if the DC voltage exceeds the predetermined value Ed1 *, the process proceeds to step S4, and the DC voltage is proportionally integrated to generate the d-axis current command value Id *. When the DC voltage is equal to or lower than the predetermined value, the process proceeds to step S3, and the process in this routine is terminated.

  By repeating the above processing, a deceleration brake operation can be performed while suppressing an increase in the DC voltage when the DC voltage exceeds a set value during deceleration.

  Here, the predetermined value Ed1 * of the DC voltage is a value equal to or higher than a voltage value at which the maximum output can be generated at a voltage lower than a voltage at which the semiconductor element (switching element) of the inverter main circuit 1 is not destroyed.

  Next, the relationship between the rotational speed of the brushless motor 2 and the DC voltage when the DC voltage suppression control is performed and not performed using the apparatus shown in FIG. 1 will be described with reference to FIG.

  FIG. 3A shows an operation without DC voltage suppression control, and FIG. 3B shows an operation with DC voltage suppression control. Also, line A shown in FIG. 3 is a sudden deceleration state where the deceleration rate is increased, line B is a deceleration state where the deceleration rate is lower than that of line A, and line C is a state where the deceleration rate is reduced so that the DC voltage does not rise rapidly. This shows the movement of the DC voltage and the rotation speed.

  In FIG. 3, it can be seen that when the DC voltage suppression control is not performed, the DC voltage is greatly increased in both the lines A and B. At this time, when the DC voltage exceeds the withstand voltage of the inverter main circuit 1, the inverter main circuit 1 is destroyed. In the prior art, in order to prevent destruction of the inverter main circuit, the power consumption circuit 11 that consumes DC power with a resistor is provided to the input of the inverter main circuit 1 so that the DC voltage does not exceed the withstand voltage of the inverter main circuit 1. The regenerative energy is consumed by the power consumption circuit 11 during deceleration.

  On the other hand, when direct current voltage suppression control according to the present invention is performed, the direct current voltage can be suppressed to a predetermined value even in the state of line A and line B as shown in FIG. Here, in the state of the line C where the deceleration rate is small, the direct-current voltage suppression control does not operate because the direct-current voltage does not reach the predetermined value. That is, when the present invention is not used, it is necessary to reduce the deceleration rate to suppress the DC voltage increase. However, if the present invention is used, sudden deceleration can be achieved even when the deceleration rate is left as it is or when the deceleration rate is increased. It becomes possible.

  Thus, in this embodiment, since the d-axis current for controlling the DC voltage and the q-axis current for controlling the output torque of the brushless motor 2 are controlled separately, the DC current is generated while generating the brake torque. An increase in voltage can be suppressed. For this reason, the motor speed can be controlled even during deceleration.

  Further, at the time of constant speed and acceleration, high-efficiency operation can be performed by setting the d-axis current command value at the optimum efficiency point.

  Furthermore, the mechanical brake mechanism and the DC power consumption circuit can be eliminated, and the washing machine can be reduced in size and weight.

  In the above embodiment, the regenerative energy of the brushless motor 2 is indirectly detected by detecting the DC voltage value. However, when detecting the regenerative energy, the input power, DC current, and brushless motor of the inverter main circuit 1 are detected. It is also possible to use input power to 2.

(Second Embodiment)
Next, a second embodiment of the present invention is shown in FIG. In the present embodiment, when the d-axis current command value Id * is generated using a direct current, a direct current detector 7b is provided instead of the direct current voltage detector 7a, and the rectifier circuit 10 and the inverter main circuit 1 are connected. A shunt resistor 71 is inserted, and a regenerative energy control circuit 70 is provided in place of the DC voltage suppression circuit 7, and the other configuration is the same as in FIG.

  The direct current detector 7 b is configured as current detection means or regenerative energy detection means for detecting a direct current flowing into the inverter main circuit 1 via the shunt resistor 71, and the detected current is input to the regenerative energy control circuit 70. ing. Here, the current flowing into the inverter main circuit 1 is represented as positive, and the current flowing out is represented as negative.

  The regenerative energy control circuit 70 takes in a direct current detected by the direct current detector 7b, outputs 0 as a d-axis current command value when the direct current value is positive, and when the direct current value becomes negative. When the regenerative current flows, it is configured as a d-axis current command value generating means for generating a d-axis current command value Id * by performing a proportional integration operation on the DC current value so that the DC current value becomes zero. ing. When a PWM signal is output from the control circuit 60 according to the d-axis current command value Id *, the regenerative energy of the brushless motor 2 is controlled to zero. At this time, the regenerative energy control can be performed after reading the rotational speed and the rotational speed command value and performing the deceleration determination.

  Thus, in this embodiment, the d-axis current is controlled so that the direct current becomes zero when the direct current, which is regenerative energy other than the direct current voltage, becomes negative, that is, when the regenerative current flows. Thus, the regenerative energy is set to 0, so that an increase in the DC voltage can be suppressed while generating the brake torque, and the motor speed can be controlled even during deceleration. Furthermore, the mechanical brake mechanism and the DC power consumption circuit can be eliminated, and the washing machine can be reduced in size and weight.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 6, the present embodiment is a control block diagram when the motor control device of the present invention is applied to a wheel drive system of an electric bicycle using the battery 100 as a power source (DC power supply).

  The brushless motor 2 in this embodiment is directly connected to the wheel 30 of the electric bicycle, and outputs a torque in accordance with a torque command (a torque command equivalent to the q-axis current command value) from the host control system to drive the wheel 30. In this embodiment, the rotational speed control circuit 5 is omitted, and a regenerative energy control circuit 8 is provided instead of the DC voltage suppression circuit 7.

  The regenerative energy control circuit 8 receives the q-axis current command value Iq *, which is a torque command from the host control system, and receives the d-axis current command value Id from which the input / output power of the brushless motor 2 becomes 0 based on the q-axis current command value. It is configured as d-axis current command value generation means for generating *, and the d-axis current command value Id * is output to the control circuit 60.

  The regenerative energy control circuit 8 outputs 0 as the d-axis current command value when the brushless motor 2 is at a constant speed and during acceleration.

  Whether the regenerative energy control circuit 8 calculates the d-axis current command value Id * is determined by detecting a DC voltage as in the first embodiment and outputting a calculation command to the regenerative energy control circuit 8 using the value. In this embodiment, the rotation speed calculation value N of the brushless motor 2 and the q-axis current command value (torque command) are used. Specifically, it is performed when the q-axis current command value, which is a torque command, is negative (reverse torque) or the rotation speed calculation value N becomes a preset overspeed value.

  The regenerative energy control circuit 8 includes an arithmetic circuit 81 that calculates a q-axis current command value Id * for setting the input / output power of the brushless motor 2 to 0 using a q-axis current command value as a torque command. A specific configuration of the arithmetic circuit 81 will be described below.

  First, since the brushless motor 2 uses a permanent magnet for the rotor, an induced voltage is always generated and regenerative energy is generated whenever it rotates. Therefore, in order to adjust the regenerative energy, it is only necessary to adjust the induced voltage by generating a demagnetizing magnetic flux in a direction that cancels the magnetic flux of the permanent magnet of the brushless motor 2. That is, if a negative current is supplied to the d-axis and the magnitude thereof is adjusted, the regenerative energy can be adjusted. The voltage equation of the brushless motor 2 is shown in the following equation (1). This voltage equation shows a case where a non-salient pole type is used as the brushless motor 2 when the current is steady.

このときのモータ入力を次の（２）式に示す。

The motor input at this time is shown in the following equation (2).

ここで、

here,

である。

It is.

The expression (2) includes a term of cos φ _v . Motor input _{P in} is the value of this for φ _v,
In the range of −π / 2 <φ _v <π / 2, P _in > 0
In the range of π / 2 <φ _v ≦ π and −π ≦ φ _v <−π / 2, P _in <0
P _in = 0 for φ _v = ± π / 2
It becomes. The above relationship is summarized as shown in FIG.

Here, phi _v a ± [pi / 2, that power factor if the (cos [phi _v) = 0, the input power of the brushless motor 2 is 0, the energy input and output is not performed. In other words, the input / output (regenerative energy) of the brushless motor 2 can be controlled by controlling the power factor to be near 0, which is a value smaller than the value during acceleration or steady operation.

Here, as a specific example, consider controlling the power factor by _obtaining the d-axis current I _d corresponding to the q-axis current I _q .

For this reason, when the relationship between _φv and d-axis current; I _d , q-axis current; I _q is obtained from the equations (5) and (6),

となる。上記（７）式より、モータ入力＝０を満足するＩ_ｄを求める。

It becomes. From the above equation (7), I _d that satisfies motor input = 0 is obtained.

Next, when V _d and V _q are eliminated using the equation (1), the following equation (8) is obtained.

（８）式における分母が０のとき、φ_ｖ＝δ−φ＝π／２となる。

When the denominator in the equation (8) is 0, φ _v = δ−φ = π / 2.

上記（９）式において、（９）式＝０とおいて、Ｉ_ｄについて解くと、次の（１０）式が得られる。

In the above equation (9), when equation (9) = 0 and solving for I _d , the following equation (10) is obtained.

ここで、図８に、（１０）式の計算結果例を示す。図８におけるグラフの曲線の左側はモータ入力正（力行）、右側はモータ入力負（回生）となる。つまり、本曲線上がモータ入出力０の状態となる。

Here, FIG. 8 shows an example of the calculation result of the equation (10). The left side of the curve in the graph in FIG. 8 is motor input positive (power running), and the right side is motor input negative (regeneration). In other words, this curve is in the state of motor input / output 0.

  If the d-axis current is determined as in the above equation (10), the input / output power of the brushless motor 2 becomes 0, and the increase of the DC voltage can be suppressed without returning the regenerative energy to the inverter main circuit 1 side. .

  In realizing the above expression (10), in this embodiment, a ROM table that calculates the d-axis current command value * from the rotation speed and the q-axis current command value is built in, and is obtained by table search by the calculation circuit 81. . However, the present invention is not limited to this, and in the case of a configuration for detecting a motor current, an actual q-axis current value may be used. Furthermore, in the case of a system in which the rotational speed range or the q-axis current range (load range) is limited, the equation (10) may be replaced with a linear approximation equation.

  Next, the relationship between the q-axis current command value, the d-axis current command value, and the DC voltage when the electric bicycle to which the above configuration is applied is actually used will be described with reference to FIG.

  In FIG. 9, the horizontal axis shows time, the gradient when the electric bicycle is used, the q-axis current command value, the d-axis current command value, and the DC voltage value. When a flat road departs from time 0, the electric train outputs a q-axis current command value to the positive side in order to perform some torque assist. At this time, the d-axis current command value is 0, and the DC voltage is the battery voltage.

  First, when the electric vehicle travels uphill at time (a), the q-axis current command value is increased to the positive side in order to perform sufficient torque assist. At this time, there is no change in the d-axis current command value and the DC voltage value.

  Next, when the uphill finishes at time (b), the q-axis current command value returns to a required value at the flat portion.

  Next, when it becomes a steep downhill at time (c), the rotation speed of the motor 2 increases, so the q-axis current command value is output to the negative side, the braking operation by the motor 2 is started, and the motor rotation speed is Slow down. Immediately after this, calculation for the d-axis current command value is started, and a d-axis current command value corresponding to the q-axis current command value is calculated. This d-axis current command value is also output to the negative side. However, after the deceleration is started and before the control of the d-axis current is started, the regenerative energy of the motor 2 returns to the DC side and the DC voltage is slightly increased, but the control of the d-axis current is started. The regenerative energy is controlled to 0 and there is no further increase in the DC voltage.

  Next, at time (d), when the slope of the downhill becomes gentle, the q-axis current value decreases accordingly, and the d-axis current value also decreases.

  Next, when the downhill finishes at time (e), it becomes the q-axis current command value when flat, and the d-axis current command value returns to zero. At this time, since the motor 2 is in a power running operation and consumes a direct current, the direct current voltage also returns to the original battery voltage.

  In this embodiment, the DC voltage is not controlled. However, by providing a charging circuit for the battery 100 and a DC voltage suppressing circuit, it is also possible to positively charge the battery 100 with regenerative energy on a downhill. is there.

  Thus, according to the present embodiment, since the d-axis current command value is directly calculated from the q-axis current command value, the input power and output power of the motor 2 are instantaneously equalized, and the increase in DC power is suppressed. can do. For this reason, the electric bicycle can output the brake torque as required by the host control system in a state in which the increase of the DC voltage is suppressed. On the downhill, when the rotational speed exceeds a predetermined value, the brake is automatically applied, and the safety of the electric bicycle can be improved.

(Fourth embodiment)
In the third embodiment, the d-axis current command value is calculated using the equation (10), but the motor constant and the q-axis current command value are used in the calculation equation. In actual cases, errors may occur due to variations in motor constants, motor temperature, and the like. Therefore, a fourth embodiment that combines the first embodiment and the third embodiment will be described below.

  In this embodiment, as shown in FIG. 10, instead of the DC voltage suppression circuit 7, the DC voltage suppression circuit 7 in the first embodiment and the regenerative energy control circuit 8 in the third embodiment are combined. In the circuit 81, the d-axis current command value is calculated from the q-axis current command value Iq *, and this calculated value is corrected by the adder 92 based on the output of the DC voltage suppression circuit 7.

  Similar to the third embodiment, the arithmetic circuit 81 includes a ROM table obtained from the equation (10), and the input / output power of the motor 2 is reduced from the q-axis current command value * generated by the rotation speed control circuit 5 to zero. The first command value is generated to generate the first command value, and the generated first command value is output to the adder 92. The DC voltage suppression circuit 7 inputs a DC voltage, performs a proportional integration operation on the DC voltage so that the DC voltage becomes a set value, generates a second command value, and adds the generated second command value to an adder The second command value generating means for outputting to 92 is configured. The adder 92 adds the first command value and the second command value, generates the added command value as a d-axis command value Id *, and outputs it to the control circuit 60 as d-axis command value generation means. It is configured.

  Here, as in the above embodiment, when the DC voltage suppression control is not necessary, the d-axis current command value is fixed to zero.

  Whether or not to operate the DC voltage suppression control is determined when the DC voltage exceeds the set value during deceleration as in the first embodiment, but only the DC voltage value can be used. It is.

  According to the present embodiment, even if there is an error in the motor constant, the d-axis current command value can be corrected by proportional integral calculation, and the optimum d-axis current command value can be output.

  Although the electric bicycle has been described in the above embodiment, the present invention can be applied to a motor-using device that can be rotated by an external force such as an electric vehicle or an air conditioner outdoor unit motor fan.

  As described above, according to each embodiment, since the brake torque and the regenerative energy are controlled separately, speed control during deceleration can be performed.

  Further, sudden addition and deceleration control of the motor 2 can be performed while suppressing the DC voltage to a predetermined value or less without adding a mechanical brake device or a power consumption circuit.

  Furthermore, when the motor 2 is rotated by an external force, the DC voltage can be prevented from rising, and the stop and deceleration operations can be performed safely. Furthermore, regenerative energy can be controlled to charge the battery 100 and adjust the generated voltage.

  On the other hand, when the motor control device is used in a washing tub driving device of a washing machine, the mechanical brake device and the power consumption circuit can be consumed, so that the weight can be reduced.

  In addition, when the motor control device is applied to an electric vehicle, automatic braking control on a slope and charging of a battery are possible, and safety can be improved.

  Further, when the present invention is applied to an outdoor unit motor fan drive device for an air conditioner, an increase in DC voltage can be prevented even if the fan is rotated by wind.

  Furthermore, when the present invention is applied to a drive device for an electric vehicle, it can be used as an engine brake.

It is a block block diagram of the motor control apparatus which shows 1st Embodiment of this invention. It is a figure for demonstrating the d-axis current output algorithm of the apparatus shown in FIG. It is a figure for demonstrating the effect | action of the apparatus shown in FIG. 1, Comprising: (a) is a wave form diagram when DC voltage suppression control is not carried out, (b) is a wave form diagram when DC voltage suppression control is carried out. It is a block block diagram of a prior art example. It is a block block diagram of the motor control apparatus which shows 2nd Embodiment of this invention. It is a block block diagram of the motor control apparatus which shows 3rd Embodiment of this invention. It is a figure for demonstrating the input-output electric power relationship of a motor. It is a characteristic view which shows the input / output electric power relationship of a motor. It is operation | movement explanatory drawing of 3rd Embodiment of this invention. It is a block block diagram of the motor control apparatus which shows 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inverter main circuit 2 Brushless motor 3 Washing tub 4a Position detector 4 Rotation speed calculation circuit 5 Rotation speed control circuit 60 Control circuit 7, 9 DC voltage suppression circuit 8 Regenerative energy control circuit 10 Rectification circuit 30 Wheel 100 Battery

Claims (3)

An inverter circuit having a DC power supply as input, a DC voltage detector for detecting a DC voltage of the inverter circuit , a motor connected to the output of the inverter circuit , and a speed detection means for detecting the speed of the motor in the motor control device,
The inverter circuit, Ri vector control type inverter circuit der for controlling the motor current of the motor is divided into q-axis current and the d-axis current of the rotating coordinate system, control the braking torque by controlling the pre-Symbol q-axis current And configured to control regenerative energy by controlling the d-axis current,
A deceleration of the motor and the when the detected voltage of the DC voltage detector exceeds a predetermined value, the detection voltage in the vicinity of zero power factor of the motor in the said predetermined value to so that a d-axis current A motor control device that outputs a command value and controls the d-axis current independently of the q-axis current . An inverter circuit having a DC power supply as an input; a DC current detector for detecting a DC current of the inverter circuit ; a motor connected to the output of the inverter circuit ; and a speed detecting means for detecting the speed of the motor. in the motor control device,
The inverter circuit, Ri vector control type inverter circuit der for controlling the motor current of the motor is divided into q-axis current and the d-axis current of the rotating coordinate system, control the braking torque by controlling the pre-Symbol q-axis current And configured to control regenerative energy by controlling the d-axis current,
When the detected current of the deceleration or the DC current detector of the motor is negative, the detected current said predetermined value to be so that a d-axis current command output current of the DC power source to close to zero A motor control device that outputs a value and controls the d-axis current independently of the q-axis current . A vector control type inverter circuit that can be controlled by dividing a q-axis current and a d-axis current of a rotating coordinate system using a DC power supply as input, a motor connected to the output of the inverter circuit , and detecting the speed of the motor In a motor control device comprising a speed detection means ,
The inverter circuit includes speed control means for calculating a q-axis current command value so that the speed of the motor becomes a predetermined value, and regenerative energy for detecting at least one of DC power, DC voltage, DC current, or motor input power. and a detection means,
When the motor decelerates or when the q-axis current command value becomes negative, the power regenerated from the motor to the DC power source is made near zero using the detection value from the regenerative energy detection means. A motor control device comprising regenerative energy control means for controlling a d-axis current independently of the q-axis current .

Images