JPH0454801A - electric car control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an electric vehicle control device, particularly to the adhesive performance of an electric vehicle that runs by energizing AC power to a plurality of induction motors using a variable voltage variable frequency inverter. The present invention relates to an electric vehicle control device suitable for improving.

[Conventional technology]

Generally, in electric vehicles, constant torque control is required for ride comfort, as described in Japanese Patent Laid-Open No. 54-3711. To achieve constant torque control in an electric vehicle that uses an induction motor as a drive motor, the voltage V and frequency f of the induction motor must be controlled so that they are proportional to CV/
f=constant) The slip frequency of the induction motor is controlled so that the current I is constant.

Figure 4 shows the configuration of a conventional electric vehicle control device.
It is composed of a frequency control means for controlling the output frequency of the inverter in accordance with the speed of the electric vehicle, and a current control means for adjusting the frequency so that the current flow becomes constant.

A rack! The DC power supply for l is pantograph 2. Filter reactor 3. It serves as an input power source for an inverter 5 via a filter capacitor 4. The inverter 5 performs orthogonal conversion and outputs a variable voltage variable frequency three-phase AC power, which is supplied to the induction motors 6A to 6D to drive the motors.

The frequency control means inputs the rotational pulses of the induction motors 6A to 6D detected by the pulse generators 7A to 7D to the frequency calculation section 8 to calculate each rotational frequency, and calculates the minimum value during power running and the maximum value during regeneration. Output reference rotation frequency f
It becomes ro. Further, the pattern generator 14 outputs a Veri frequency pattern fsP necessary for torque control, which is added (subtracted) to the reference rotation frequency f ro by the adder 13.
The inverter frequency f INV is inputted to the inverter 5 to control the output frequency.

On the other hand, the current control means detects the output current of the inverter 5 with the current transformer 9, and the output value IM obtained by calculating the effective value in the current detection section 10 is inputted to the comparator 11, and is outputted from the pattern generator 14. It is compared with the current pattern Ip, and its deviation Δ
Is is output.

ΔIM is input to the slip frequency calculating section 12, becomes the slip frequency deviation value Δfs, is input to the adder/subtracter 13, and is controlled to adjust the slip frequency so that the current becomes constant.

In such a conventional control method, in a normal state where no slipping or the like occurs, the slip frequency and current are controlled to be constant by the action of the frequency control means and the current control means, and constant torque control is performed. However, when any of the axles driven by the induction motor slips or skids, the current IM also decreases as the slip frequency of the induction motor decreases, but the current control means controls the decrease in the output current IM to the slip frequency. Since the deviation value Δfs is used to control the current pattern so that it approaches the current pattern Ip, the torque of the idling (sliding) axis does not decrease and is likely to cause a large idling (large sliding).In addition, the torque of the sticky axis also increases, so There are problems such as inducing slippage (sliding) and many opportunities for all axes to slip or slide.

In order to solve the above-mentioned drawbacks of the conventional technology, there is a proposal to provide a current control means that detects the current of one phase of each induction motor and controls the maximum current value to be constant (for example, Japanese Patent Laid-Open No. However, in a region where the frequency of the inverter is low, it takes time to detect the current, and stable control is difficult. It is also conceivable to detect all three-phase currents as shown in FIG. 4, but this is not preferable from an economic point of view.

[Problems to be Solved by the Invention] As described above, the above-mentioned conventional technology does not take into consideration the point of fully effectively utilizing the self-readhesive property of the induction motor and performing stable constant torque control. In order to suppress slipping or skidding, it is necessary to provide a readhesion control system that temporarily reduces torque, which not only complicates the configuration of the control system but also has a negative effect on riding comfort.

An object of the present invention is to provide an electric vehicle control device that utilizes the self-readhesive property of the induction motors to improve adhesive performance in an electric vehicle that supplies power to a plurality of induction motors from one inverter. .

[Means to solve the problem]

In order to achieve the above object, the present invention monitors the movement of all induction motors based on rotational frequencies, detects the slip frequency of the induction motor in a sticky state based on the monitoring results, and detects the slip frequency of the induction motor in a sticky state. Find the current signal,
This current signal and the current pattern are compared to perform constant current control, and the output frequency of the inverter is controlled so that the maximum value of the slip frequencies of the plurality of induction motors is below a certain value.

[Effect]

That is, each rotational frequency detected from a plurality of induction motors connected in parallel to one inverter is selected by a frequency calculation unit as a minimum value during power running and a maximum value during one regeneration, and a reference rotational frequency f ro is output. This reference rotation frequency Jro
represents the rotational frequency of the induction motor in a sticky state unless all axles are idling or running smoothly, and the deviation value from the inverter output frequency f rNv indicates the slip frequency of the induction motor in a sticky state.

On the other hand, as shown in FIG. 5, the general characteristics of an induction motor are that the slip frequency and current have a one-to-one correspondence in a range where the slip frequency is relatively small. That is, detecting the 8-power frequency and rotation frequency of the inverter is the same as detecting the current IN.

The present invention takes advantage of this point, and includes a motor current calculation unit that stores the relationship between the slip frequency and current of the induction motor energized by the inverter, and the inverter output obtained from the inverter frequency control means. frequency j
INν and reference rotational frequency f ro are input, and a motor current signal IMO corresponding to these is output. This motor current signal IMO is.

IM because it always shows the current value of the induction motor in a sticky state unless all the shafts are idling or sliding.

and the current pattern Ip, find the slip frequency deviation value Δfs from the deviation value, adjust the slip frequency, and control the current so that it is constant, then the slipping shaft can be driven by the slipping of any axle. Even if the rotational speed of the induction motor increases, the reference rotational frequency f, , c (minimum rotational speed of each induction motor during power running) does not change. Therefore, the motor current signal IMo also does not change, and the torque of each induction motor remains the same as when all the shafts are in the sticky state. Therefore, the torque of the induction motor that drives the idling shaft decreases rapidly due to the increase in rotational speed due to idling, leading to readhesion. The torque of other sticky shafts will not increase, and slipping will not be induced.

From this phenomenon, it can be understood that the brake torque when sliding occurs during regeneration also has readhesion characteristics.

In this way, when slipping or skidding occurs, it is possible to obtain a control device that automatically moves to re-adhesion if there is a sticky axis even on the negative axis, and all axes are freed or skidded.

Unless the vehicle is skidding on all axes, there is no need to perform forced readhesion control to detect and suppress slipping or skidding.

In addition, in an electric vehicle in which an electric vehicle driven by an induction motor and an accompanying vehicle without drive equipment are connected, and a speed signal is obtained from the accompanying vehicle, the frequency calculation section receives the speed signal (following wheel speed signal) from the accompanying vehicle. By adding the minimum value of all speed signals during power running and the maximum value of all speed signals during regeneration, and setting the reference rotation frequency f ro, all axes of the electric vehicle are idling or sliding. However, since each induction motor has a self-readhesive property, if the adhesion between the wheel rails is improved, it becomes possible for the wheels to automatically readhere.

〔Example〕

The present invention will be explained below using examples.

FIG. 1 is a control block diagram showing an embodiment of the electric vehicle control device of the present invention. This embodiment differs from the conventional method shown in FIG. A motor current calculation unit 15 that stores the relationship between the slip frequency and current of 6D is provided, and the output frequency signal fInv input to the inverter 5 and the reference rotation frequency signal f ro output from the frequency calculation unit 8 are inputted and From the difference, find the slip frequency of the induction motor in the sticky state, output the motor current signal 1 corresponding to this, and send this to comparator 1.
It is at the point where the input signal is 1.

That is, during power running, the minimum value of the rotational speed signals detected by the pulse generators 7A to 7D incorporated in each induction motor 6A to 7D is selected as the reference rotational frequency signal f ro that is the output of the frequency calculation unit 8, Sometimes the maximum value is selected. Therefore, unless all of the wheel axles driven by the induction motor are idling or sliding, the selected and output reference rotational frequency signal f ro indicates the rotational frequency of the induction motor in a sticky state, so it is different from the output frequency flNv of the inverter. The slip frequency expressed by the difference becomes the maximum slip frequency of each induction motor, and the motor current signal IMO calculated based on this also becomes the current of the induction motor in the sticky state (that is, the maximum current). is input to the comparator 11, which compares it with the current pattern Ip, outputs the deviation value ΔIN, which becomes the slip frequency deviation value Δfs via the slip frequency calculation unit 12, and is input to the adder/subtractor 13 to keep the motor current constant. Adjust the slip frequency so that

Now, if any of the wheel axles driven by the induction electric motor @6A to 6D idles, the pulse generator 7A of the idle axis
Although the rotational speed signal detected from ~7D increases, the reference rotational frequency signal f ro for which the maximum value is selected does not change, and the motor current signal IMO also does not change, so the torque of the induction motor of the idling shaft remains idling. Due to the increase in rotational speed associated with this, it rapidly decreases and automatically leads to re-adhesion. In addition, the torque of the other sticky shafts does not change because there is no change in current, and no slipping is induced.

As described above, according to this embodiment, when the induction motors connected to each axle are connected in parallel, even if any of the axles spins, if at least one wheel axle is stuck, Since the wheel axle that has spun quickly becomes sticky again, high acceleration/deceleration and high adhesion operation is possible. In addition, it is expected to reduce the number of electric vehicles on trains, which has a large economic effect, and compared to the follow-up method, it has the effect of significantly improving ride comfort because there is less torque change during slipping and skidding.

FIG. 2 shows another embodiment of the invention. The difference from FIG. 1 is that the output current of the inverter 5 is detected by a current transformer 9, and is converted into an output value IM that can be calculated by a current detector 10 and compared with the motor current signal IMO. The point is to select and output the high value IMM of the motor current signal IMO and the output voltage IN of the inverter 5. In the case of this embodiment, in addition to the effect of the embodiment shown in FIG. It is controlled so that the IM does not rise above a predetermined value,
Since the inverter 5 and the induction motors 6A to 6D are protected, reliability is improved.

FIG. 3 shows another embodiment of the invention. In the case of this embodiment, the output of the following wheel speed detector 17 provided on the axle shaft of the accompanying vehicle (not shown) is added to the frequency calculation unit 18, and the rotation speed signal of each induction motor 6A to 6D and the following wheel speed detector are added to the frequency calculating section 18. The minimum value (during power running) or the maximum value (during regeneration) is selected from among the rotation speed signals obtained from 17 and the reference rotation frequency signal f
Since ro is obtained, even if all the wheel axles driven by each induction motor spin or slide, they are automatically re-adhesive as described in detail with reference to FIG. 1.

In each of the embodiments, a pulse generator built into each induction motor was used to determine the rotational speed lateral ratio, but the same effect can be obtained even if the rotational speed of the induction motor is detected by other rotational speed detection means.

〔Effect of the invention〕

According to the present invention, it is possible to provide an electric vehicle control device for an induction motor with excellent adhesion performance, and to enable high acceleration and high deceleration operation. In addition, it is expected to reduce the number of electric vehicles on trains, so it will have a large economic effect.

Furthermore, since the torque change during slipping and skidding is small, the riding comfort is improved.

[Brief explanation of the drawing]

FIG. 1 is a control block diagram showing one embodiment of the present invention, and FIG.
Fig. 3 is a control block diagram showing another embodiment of the present invention, Fig. 4 is a control block diagram showing a conventional example, and Fig. 5 is a control block diagram showing another embodiment of the present invention.
The figure is a general characteristic diagram of an induction motor. 5... Inverter, 6A-6D... Induction motor, 7
A~7D...Pulse generator, 8.18...Frequency diagram, Figure 3, Figure 4

Claims (1)

[Claims] 1. In an electric vehicle control device that energizes a plurality of induction motors with a single inverter, from the output frequency of the inverter controlled by a frequency control means and the rotational speed of the plurality of induction motors. detecting a reference rotation frequency corresponding to each running pattern, calculating a motor current signal of the induction motor corresponding to the deviation value, and determining a slip frequency deviation value from the deviation value between the motor current signal and the current pattern; An electric vehicle control device characterized in that the output current of the inverter is controlled by adjusting the slip frequency of the frequency control means. 2. In an electric vehicle control device that energizes a plurality of induction motors with a single inverter, the output frequency of the inverter controlled by the frequency control means and the rotational speed of the plurality of induction motors are used to determine the frequency according to each running pattern. Detects the reference rotation frequency and calculates the motor current signal of the induction motor corresponding to the deviation value.
A first current detecting means for outputting an output current and a second current detecting means for detecting an output current of the inverter using an alternator are provided, and a higher level between the output of the first current detecting means and the output of the second current detecting means is provided. Electric vehicle control characterized in that the value is compared with a current pattern, a slip frequency deviation value is determined from the deviation value, and the slip frequency of the frequency control means is adjusted based on the deviation value, and the output current of the inverter is controlled. Device. 3. In claim 1 or 2, the reference rotational frequency is selected based on the rotational frequency of the plurality of induction motors and the rotational frequency calculated based on the trailing wheel speed detected from the accompanying vehicle, and the An electric vehicle control device that selects and outputs the maximum value during regeneration.