JP2551549B2 - Induction motor type electric vehicle controller - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an induction motor type electric vehicle that drives a vehicle by supplying power to an induction motor from a DC power source via an inverter.

[Background of the Invention]

Recently, in the field of electric railways, development of an induction motor type electric vehicle by inverter control has been advanced.

FIG. 1 is an electric circuit diagram showing the configuration of a conventional induction motor type electric vehicle control device by an inverter control, in which 1 is a DC overhead wire, 2 is a pantograph, 3 is a reactor L _F and a capacitor C _F , A filter for reducing harmonic components contained in the current I _S , 4 a pulse width modulation inverter, 5 an induction motor, 6 a speed frequency according to the vehicle speed
f _n , that is, means for generating the rotation frequency of the induction motor 5, and 7 is a slip frequency corresponding to the slip of the induction motor 5.
A means for setting f _s , 8 is a slip frequency f _{s for the} velocity frequency f _n
Is added / subtracted to obtain the operating frequency of the inverter 4, that is, the output frequency f (f = f _n + f _s during power running, f = f _n − during regeneration).
f _s ) frequency control means, 9 is the capacitor C _F voltage
Means for detecting E _cf , and 10 is a voltage control means for controlling the conduction ratio γ of the inverter 4, that is, the output voltage of the inverter 4, by the detected value of the capacitor C _F voltage E _cf and the operating frequency f of the inverter 4.

In FIG. 1, in order to accelerate / decelerate the induction motor 5 with a constant torque, the magnetic flux of the induction motor 5, that is, V (voltage) / f
(Frequency) and the electric motor current I _M are kept constant, and the V / f of the induction motor 5 is controlled by the voltage control means 10 so that it is constant even if the voltage E _{S of the} overhead line 1 changes. I _M
Is the deviation between the command value I _MP and the output of the current detection means 13 (I _MP −I _M ).
Is applied to the slip frequency setting means 7 and controlled by its output (slip frequency). However, with such control alone, as described in Japanese Patent Laid-Open No. 57-145503 already proposed by the present inventors, the input current I _D of the inverter 4 (current I _S flowing through the overhead wire 1) is filtered by the filter circuit. Resonating with 3, electric vibration is generated. Therefore, the current I _S flowing through the electric oscillation in the overhead line 1, is detected by an electrical vibration detecting means 11 of the current transformer or the like with Giyatsupu provides its output to the electric vibration suppressing means 12, suppressing the electric oscillation by the output The operating frequency f of the inverter 4 is controlled so that This electric vibration suppression means
For details of the specific construction of 12 and the electric vibration suppressing operation by this means, refer to the above-mentioned JP-A-57-145503.

Then, by the method of suppressing the electric vibration as described above, the present inventors variously change the gain of the electric vibration suppressing means 12,
A stable range in which electric vibration does not occur was experimentally obtained using the voltage E _{S of the} overhead wire 1 as a parameter. As a result, the stable range becomes mountainous with respect to the operating frequency f of the inverter 4 as shown in FIG. 2, and the stable range changes with respect to the voltage E _S of the overhead line 1 as shown in FIG. It has been found that the gain of the suppressing means 12 may be lower when the voltage E _S of the overhead line 1 is high (solid line in FIG. 2) than when it is low (dotted line in FIG. 2).
Therefore, even if the gain of the electric vibration suppressing means 12 is set to the one-dot chain line in FIG. 2 so as to be stable when the voltage E _{S of the} overhead line 1 is high, the voltage E _{S of the} overhead line 1 is low. In this case, electric vibration will occur. In addition, when was the row summer Similar experiments motor current I _M (current command value I _MP) as parameters, as shown in FIG. 3, when the gain of the electrical vibration suppressing means 12 small motor current I _M (No. It has been found that the solid line in FIG. 3) may be lower than the case where it is large (dotted line in FIG. 3). Therefore, even if the gain of the electric vibration suppressing means 12 is set to the one-dot chain line in FIG. 3 so as to be stable when the electric motor current I _M is small, the electric vibration is generated when the electric motor current I _M is increased. Will occur. Furthermore, as shown in FIG. 4 for power running and regeneration, the gain of the electric vibration suppressing means 12 may be lower in the case of regeneration (solid line in FIG. 4) than in the case of power running (dotted line in FIG. 4). Ivy. Therefore, even if the dashed line of FIG. 4 is set so that the gain of the electric vibration suppressing means 12 is stable in the case of regeneration, electric vibration is generated in the case of power running.

As described above, in the conventional example, the gain of the electric vibration suppressing means 12 depends on the operating conditions of the electric vehicle (the voltage E _{S of the} overhead wire 1 and the electric motor current).
Since it is constant regardless of I _M , power running and regeneration), electric vibration occurs when operating conditions change, which causes commutation failure of the inverter 4 and torque fluctuation, which in turn makes it impossible to operate the electric vehicle smoothly. I got it.

[Object of the Invention]

The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art,
An induction motor type electric vehicle that can be stably controlled without generating electric vibration even if the operating conditions of the electric vehicle such as the voltage of the DC power supply, the current of the induction motor, the output frequency of the inverter, and the operation modes of power running and regeneration are changed. It is to provide the control device.

[Outline of Invention]

In order to achieve the above object, the present invention corresponds to an inverter fed from a DC power source through a filter circuit, a vehicle driving induction motor energized by the inverter, and a rotation frequency and slip of the induction motor. Frequency control means for controlling the operating frequency of the inverter by adding / subtracting the slip frequency, voltage control means for controlling the output voltage of the inverter, and detecting vibrational fluctuations in the amount of electricity in the circuit from the DC power supply to the induction motor. And a means for adjusting the operating frequency of the inverter so as to suppress the electric vibrations according to the output of the means for detecting the vibrational fluctuations. Either the operating frequency of the inverter or the motor rotation frequency output from the means, and the DC power supply From the voltage, the current flowing in the induction motor, and at least one of the powering mode and the regenerative operation mode, an electric vibration set based on a characteristic in which the gain of the output of the means for adjusting the operating frequency is detected in advance is It is characterized in that means for increasing / decreasing the output of the means for adjusting the operating frequency is provided so as to fall within a stable range where it does not occur.

Example of Invention

Hereinafter, the present invention will be described in detail based on the illustrated embodiments.

FIG. 5 is an electric circuit diagram showing an embodiment of the present invention.
The difference from the conventional example of FIG.
Since the means 14A for increasing / decreasing the output of the capacitor C _F voltage E _cf and the operating frequency f of the inverter 4 is provided, and the operating frequency f of the inverter 4 is controlled by the output, other symbols are the first. It is the same as the figure.

As shown in FIG. 6, the increasing / decreasing means 14A includes function generators 15 to 17, a low-priority circuit 18, a subtractor 19 and a multiplier.
It consists of 20. The function generator 15 is supplied with the capacitor C _F voltage E _cf which is the output of the voltage detection means 9, and the function generators 16 and 17 are respectively supplied with the operating frequency f of the inverter 4 which is the output of the frequency control means 8, Each produces an output with the characteristics shown. The low-order priority circuit 18 inputs the outputs of the function generators 15 and 16, compares them, and outputs the low-order one (solid line in the figure). The subtractor 19 subtracts the output of the function generator 17 from the output of the low-priority circuit 18 to generate an output as shown by the solid line in the figure. Incidentally, flats (constant) part of the output of the low priority circuit 18 and the subtractor 19, as shown by the arrow, when the voltage E _cf (E _S) is low upward, is higher moves downward. By multiplying the output of the subtractor 19 and the output of the electric vibration suppressing means 12 by the multiplier 20, the characteristic as shown in FIG. 7 is obtained.

The operation of this embodiment will be described with reference to FIG. The gain including the electric vibration suppressing means 12 and the means 14A for increasing / decreasing the output of the electric vibration suppressing means 12 is as shown by the one-dot chain line G ₁ and the two-dot chain line G ₂ in FIG.
The operating frequency f of the inverter 4 should be low where it is low and high, and low when the voltage E _{S of the} overhead line 1 is high (dashed line G _{1 in} FIG. 7) and the voltage E _{S of the} overhead line 1 is low. In this case, it is set to be high (two-dot chain line G _{2 in} FIG. 7). Then, the voltage E _{S of the} overhead line 1 changes, and the stable range changes from the solid line of FIG. 7 when the voltage E _S of the overhead line 1 is high to the dotted line of FIG. 7 when the voltage E _S of the overhead line 1 is low. Even if it changes, the electric vibration suppressing means 12 and means 14A for increasing or decreasing its output
Gain, including, in response to the change of the voltage E _S of the overhead line 1, the seventh is lower from the one-dot chain line G ₁ of FIG. 7 in the case of high voltage E _S of overhead wire 1 of the voltage E _S of the overhead line 1 Figure since changes to the two-dot chain line G _2, means 14 for increasing or decreasing the electrical vibration suppression means 12 and the output
The gain including A is always in the stable range as shown in FIG. 7, and electric vibration does not occur unlike the conventional example. In addition, in order to increase or decrease the output of the electric vibration suppressing means 12, not only the capacitor C _F voltage C _cf and the operating frequency f of the inverter 4, but also the voltage E _{S of the} overhead wire 1 and the speed frequency f _n may be used. Absent.

As described above, according to the embodiment of FIG. 5, even if the voltage E _{S of the} overhead wire 1 changes, stable control can be performed without generating electric vibration, the inverter 4 fails in commutation, or torque fluctuations occur. The effect is that there is no occurrence of.

FIG. 8 is an electric circuit diagram showing another embodiment of the present invention. The difference from the embodiment of FIG. 5 is that means 14B for increasing / decreasing the output of the electric vibration suppressing means 12 according to the motor current I _M and the operating frequency f of the inverter 4 is provided, and the operating frequency f of the inverter 4 is increased by the output. By controlling it,
Other reference numerals are the same as those in FIG.

As shown in FIG. 9, the increasing / decreasing means 14B includes function generators 16, 17, a low-priority circuit 18, a subtractor 19 and a multiplier 2.
Consists of 0. The operation frequency f of the inverter 4 which is the output of the frequency control means 8 is input to the function generators 16 and 17, respectively, and each output of the characteristic shown in the figure is generated. The low-level priority circuit 18 inputs the motor current I _M , which is the output of the current detection means 13, and the output of the function generator 16, compares them, and outputs the low-level (solid line in the figure). Subtractor 19
Generates the output as shown by the solid line by subtracting the output of the function generator 17 from the output of the low priority circuit 18. The flat (constant) portion of the outputs of the low-priority circuit 18 and the subtractor 19 moves upward when the electric motor current I _M is large and downward when the electric motor current I _M is small. This subtractor 19
By multiplying the output of 1 and the output of the electric vibration suppressing means 12 by the multiplier 20, the characteristic shown in FIG. 10 is obtained.

The operation of this embodiment will be described with reference to FIG. The gain including the means 12B for increasing and decreasing the electric vibration suppressing means 12 and its output is, as shown by the one-dot chain line G ₃ and the two-dot chain line G ₄ in FIG. 10,
It should be low at low and high operating frequencies f of the inverter 4, high when the motor current I _M is large (two-dot chain line G _{4 in} FIG. 10), and low when the motor current I _M is small. Set it so that it is low (dotted line G _{3 in} Fig. 10). Then, the motor current I _M is changed by the command value I _MP so that the stable range changes from the solid line in FIG. 10 when the motor current I _M is small to the dotted line in FIG. 10 when the motor current I _M is large. be varied, gain, including means 14B to increase or decrease the electrical vibration suppression means 12 whose output, the electric motor in accordance with a change in the current I _M, the motor current I dashed line 10 view when _M small G ₃ When the motor current I _M is large, it changes to the alternate long and two short dashes line G _{4 in} FIG. 10, so that the gain including the electric vibration suppressing means 12 and the means 14B for increasing / decreasing its output is always as shown in FIG. It is in the stable range, and electric vibration is not generated unlike the conventional example. The electric vibration suppressing means 12
To increase or decrease the output of the motor current I _M , inverter 4
Not only the operating frequency f of but also the command value of the motor current I _M
Needless to say, I _MP and speed frequency f _n are also acceptable.

As described above, according to the embodiment of FIG.
Even if I _M changes, there is an effect that stable control can be performed without generating electric vibration, and commutation failure of the inverter 4 or torque fluctuation does not occur.

FIG. 11 is an electric circuit diagram showing another embodiment of the present invention. 5 and 8 is different from each embodiment in that the output of the electric vibration suppressing means 12 is increased / decreased by the operating frequency f of the inverter 4 and the amount of increase / decrease corresponds to the operation mode (power running and regeneration). By providing a means 14C for switching and adjusting by means of a switch SW and controlling the operating frequency f of the inverter 4 by its output, the other symbols are the same as those in FIGS. 5 and 8.

As shown in FIG. 12, the increasing / decreasing means 14C comprises function generators 16 and 17, a subtractor 19, a multiplier 20, a switch SW and an amplifier 21 (gain K). Function generator
The operating frequency f of the inverter 4, which is the output of the frequency control means 8, is input to 16 and 17, respectively, and outputs with the characteristics shown in the drawing are generated. In the subtractor 19, the function generator
The output of the function generator 17 is subtracted from the output of 16 to generate the output indicated by the solid line in the figure. The output of the subtractor 19 is multiplied by the output of the electric vibration suppressing means 12 in the multiplier 20. Multiplier
The output of 20 is that the switch SW is
Since the switch SW is switched to the side, the switch SW is switched to the side b by the regeneration command during the regeneration, and thus the amplifier 21 multiplies it by K (K <1) and outputs it.
As a result, the characteristics shown in FIG. 13 are obtained.

The operation of the embodiment shown in FIG. 11 will be described with reference to FIG.
The gain including the electric vibration suppressing means 12 and the means 14C for increasing / decreasing the output of the inverter 4 is set at a low operating frequency f and a high operating frequency f of the inverter 4 as shown by the one-dot chain line G ₅ and two-dot chain line G ₆ in FIG. Is set to be low, high for power running (two-dot chain line G _{6 in} FIG. 13), and low for regenerative (one-dot chain line G _{5 in} FIG. 13). Then, by switching between power running and regeneration, even if the stable range changes from the dotted line in FIG. 13 in the case of power running to the solid line in FIG. 13 in the case of regeneration, the electric vibration suppressing means 12 and means for increasing or decreasing the output thereof. The gain including 14C accordingly changes from the two-dot chain line G _{6 in} FIG. 13 in the case of power running to the one-dot chain line G _{5 in} FIG. 13 in the case of regeneration, so the electric vibration suppressing means 12 and its output Means to increase or decrease 14C
As shown in FIG. 13, the gain including is always within the stable range, and electric vibration does not occur unlike the conventional example. It goes without saying that the output of the electric vibration suppressing means 12 may be increased or decreased not only by the operating frequency f of the inverter 4 but also by the speed frequency f _n .

As described above, according to the embodiment of FIG. 11, even if the operation mode (power running and regeneration) is changed, stable control can be performed without generating electric vibration, and the inverter 4 fails in commutation.
The effect is that torque fluctuations will not occur.

In each of the embodiments shown in FIGS. 5, 8, and 11 above, when the voltage E _{S of the} overhead wire 1 changes, when the motor current I _M changes, and when the operation mode (power running and regeneration) changes. However, depending on the operating conditions (voltage E _{S of} overhead line 1, motor current I _M and operating mode (power running and regeneration), these examples may be used together, for example, as shown in FIG. 5 (voltage E of overhead line 1). It is needless to say that the embodiment shown in FIG. 14 may be combined with the embodiment of FIG. 11 (when _S is changed) and FIG. 11 (when operation mode (power running and regeneration) is changed).

That is, in the embodiment of FIG. 14, the electric vibration suppressing means 12
The output of is increased / decreased by the capacitor C _F voltage E _cf and the operating frequency f of the inverter 4, and the amount of increase / decrease is switched and adjusted by the switch SW in accordance with the operation mode (power running and regeneration). Since the operating frequency f of the inverter 4 is controlled by the output, the other symbols are the same as those in FIGS. 5, 8 and 11.

The increasing / decreasing means 14D is, as shown in FIG. 15, function generators 15 to 17, a low priority circuit 18, a subtractor 19, a multiplier 20,
It is composed of a switch SW and an amplifier 21 (gain K).

The influence of the voltage E _S fluctuation in the stable range as shown in FIG. 7 has the same tendency during power running and during regeneration. However, as shown in FIG. 13, the gain including the electric vibration suppressing means 12 for suppressing electric vibration and the means 14D for increasing / decreasing the output thereof may be smaller than that during power running as shown in FIG. Therefore, in FIG. 15, the switch SW is switched to the a side during power running to suppress electric vibration in the same manner as in FIG. 6 (at this time, the characteristic of FIG. 7 is obtained), and during regeneration, By switching the switch SW to the b side and passing the output of the multiplier 20 through the amplifier 21, the gain including both the means 12 and 14D is set to K (K <of the gain at the time of power running (gain of characteristic in FIG. 7). 1) Double to suppress electric vibration.

Further, in each of the above-described embodiments, the electric vibration is detected by the current I _S flowing through the overhead wire 1, but the capacitor C _F voltage
It goes without saying that it may be detected by E _cf or the motor current I _M.

〔The invention's effect〕

As described above, according to the present invention, from either the operating frequency of the inverter or the motor rotation frequency, the voltage of the DC power supply, the current flowing in the induction motor, and at least one of the powering and regeneration operation modes, Since the means for increasing or decreasing the output of the means for adjusting the operating frequency is provided so that the gain of the output of the means for adjusting the operating frequency falls within a stable range in which electric vibration does not occur, which is set based on the characteristics previously detected. Even if these conditions change, stable control can be performed without generating electric vibration, and the inverter can be operated smoothly without commutation failure or torque fluctuation. can do.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of a control device for a conventional induction motor type electric vehicle, and FIGS. 2 to 4 are operation explanatory diagrams of the control device, and FIG.
FIG. 6 is an electric circuit diagram of a control device according to an embodiment of the present invention, FIG. 6 is a detailed block diagram of means for increasing / decreasing the output of the electric vibration suppressing means in the control device, and FIG. 7 is an explanation of the operation of the control device. FIG. 8 is an electric circuit diagram of a control device according to another embodiment of the present invention, FIG. 9 is a detailed block diagram of means for increasing / decreasing the output of the electric vibration suppressing means in the control device, and FIG. 10 is the same. Fig. 11 is an operation explanatory view of the control device, Fig. 11 is an electric circuit diagram of the control device according to still another embodiment of the present invention, and Fig. 12 is a detailed block diagram of means for increasing / decreasing the output of the electric vibration suppressing means in the control device. , FIG. 13 is an operation explanatory view of the control device,
FIG. 14 is an electric circuit diagram of a control device according to still another embodiment of the present invention, and FIG. 15 is a detailed block diagram of means for increasing / decreasing the output of the electric vibration suppressing means in the control device. 1 ... DC overhead wire, 3 ... filter circuit, 4 ... inverter, 5 ... induction motor, 6 ... speed frequency generating means, 7
...... Slip frequency setting means, 8 ...... Frequency control means, 10
...... Voltage control means, 11 ...... electric vibration detecting means, 12 ...... electric vibration suppressing means, 14A to 14D ...... means for increasing or decreasing the output of the electric vibration suppressing means.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Horie 1070 Ichige Katsuta City Mito Plant, Hitachi Ltd. (72) Inventor Kingo Abe 1070 Ichige Katsuta City Mito Plant, Hitachi Ltd. ( 56) References JP-A-57-145503 (JP, A) JP-A-54-75708 (JP, A)

Claims (1)

(57) [Claims] 1. An inverter fed from a DC power source through a filter circuit, an induction motor for driving a vehicle which is energized by the inverter, a rotational frequency of the induction motor, and a slip frequency corresponding to a slip, and the slip frequency corresponding to the slip is added and subtracted. Frequency control means for controlling the operating frequency of the inverter, voltage control means for controlling the output voltage of the inverter, means for detecting the oscillatory fluctuation of the amount of electricity in the circuit from the DC power supply to the induction motor, and the vibration In a control device for an induction motor type electric vehicle, which comprises means for adjusting the operating frequency of the inverter so as to suppress electric vibration in accordance with the output of the means for detecting dynamic fluctuation, the output from the frequency control means With either the operating frequency of the inverter or the motor rotation frequency,
The gain of the output of the means for adjusting the operating frequency is set based on the characteristics detected in advance from the voltage of the DC power supply, the current flowing in the induction motor, and at least one of the powering mode and the regeneration mode. A control device for an induction motor type electric vehicle, further comprising means for increasing / decreasing the output of the means for adjusting the operating frequency so as to be within a stable range in which electric vibration does not occur.