JPH0454802A - electric car control device - Google Patents

Abstract

PURPOSE:To realize high acceleration/deceleration by obtaining variation of reference rotational frequency for powering and regeneration of a plurality of motors to be driven with VVVF power of an inverter with a predetermined time interval and then correcting a reference rotational frequency signal. CONSTITUTION:Motors 6A-6D are driven with the output from an inverter 5 and rotational frequencies are detected 7A-7D, and a frequency operating section 8 provides the judging circuit 22 in a reference rotational frequency operating section 16 with rotational frequency signals frm for powering and regeneration. A pattern generator 15 outputs a slip frequency pattern signal fsp, a current command value Ip and acceleration/deceleration patterns alphap(betap) based on an operation command. An operating section 16 operates 19-21 two preceding reference rotational, frequencies fr01, fr02 and signals alphap(betap) and discriminates 22 between powering and regeneration thus producing a new reference rotational frequency signal fr0. Difference IM. between the current command value Ip and an actual current IM is then converted 12 into a frequency difference fs. The signals fsp, fro, fs are then subjected to addition/subtraction 13 in order to control the inverter 5.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is an electric vehicle control device, particularly a variable voltage variable frequency inverter that applies AC power to a plurality of induction motors to improve the adhesion performance of a running electric vehicle. The present invention relates to an electric vehicle control device suitable for.

[Conventional technology]

In general, electric vehicles require constant torque control in order to improve riding comfort. In order to achieve constant torque control in an electric vehicle that uses an induction motor as a drive motor, control is performed so that the voltage of the induction motor is proportional to the frequency J.
(V/f=constant) The slip frequency of the induction motor is controlled so that the current I is constant.

Figure 3 shows the configuration of a conventional electric vehicle control device.
It consists of frequency control means that controls the output frequency of the inverter in accordance with the speed of the electric vehicle, and current control means that adjusts the slip frequency so that the current flow remains constant.

The DC power source for overhead line 1 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 convex metal 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, calculates each rotational frequency, and selects the minimum value during power running and the maximum value during regeneration. , this becomes the reference rotational frequency f ro corresponding to the speed of the vehicle. In addition, the pattern generator 14 outputs a slip frequency pattern fsp necessary for torque control, which is added (subtracted) to the reference rotation frequency f ro by the adder/subtractor 13 to generate the inverter frequency J1.
N and J, and are input to the inverter 5 to control the output frequency.

The current control means detects the output current of the inverter 5 with the current transformer 9, and calculates the effective value IN with the current detection section 10.
is input to the comparator 11 and compared with the current pattern IP output from the pattern generator 14, and its deviation ΔIM is output. ΔIs is input to the slip frequency calculating section 12, becomes the slip frequency deviation value Δfs, and is input to the adder/subtractor 13, where the slip frequency is adjusted and controlled so that the output current is constant.

In such conventional control methods, under normal conditions where no slipping occurs, the frequency control means and the current control means:
The slip frequency and current ■ are controlled to be constant, and constant torque control is performed. However, if the adhesion between the axle and the rail is poor and all of the axles driven by the induction motor slip (hereinafter referred to as "all axes idling" or "all axes sliding")
Since the reference rotational frequency f'ro no longer corresponds to the speed of the vehicle (indicating the rotational frequency of the idling shaft) and the output frequency of the inverter 5 also increases accordingly, readhesion becomes impossible. Furthermore, since the decrease in the output current IN is controlled by the deviation value Δfs of the slip frequency so as to approach the current pattern Ip, the torque does not decrease, which tends to cause a large slip. Note that this phenomenon also applies to sliding on all axes during regeneration.

This conventional technology does not take into consideration the improvement of adhesive performance in the case of all axes idling or all axes sliding, and there was a risk that the drive shaft system would be worn out due to large idling or large sliding.

In addition, it is necessary to install a readhesion control device that temporarily significantly reduces the torque to achieve readhesion, which causes a large drop in traction and has a negative effect on riding comfort.

An object of the present invention is to prevent the reference rotation frequency fro for controlling the output frequency of the inverter from becoming incompatible with the speed of the vehicle even if an inverter-controlled electric vehicle causes all axes to idle or skid. An object of the present invention is to provide an electric vehicle control device which configures a frequency control means to make maximum use of adhesive force.

[Means to solve the problem]

In order to achieve the above object, the present invention selects the minimum value during power running and the maximum value during regeneration from the rotation speeds detected from a plurality of induction motors to obtain a reference rotation frequency signal, and also obtains a reference rotation frequency signal for each predetermined calculation cycle. Detect the rotational frequency signal, its time variation, and the frequency deviation value corresponding to the time variation of the acceleration/deceleration pattern, additively synthesize these to obtain a signal equivalent to the rotational frequency of the adhesive shaft, and use this output signal to The output frequency of the inverter is controlled by the corrected reference rotation frequency signal.

[Effect]

FIG. 4 shows waveforms explaining the operation of each rotational frequency signal during idling.

Waveform (1) is a rotation frequency signal obtained by selecting the minimum value during power running and the maximum value during regeneration among the rotation speeds detected from multiple induction motors, and waveform (2) is a rotation frequency signal obtained by selecting the minimum value during power running and the maximum value during regeneration. A signal corresponding to the rotational frequency of the adhesive shaft, waveform (3), is an acceleration/deceleration pattern signal of the electric vehicle determined by a driving command or the like.

The rotational frequency signal detected from the rotational speed of the induction motor indicates the rotational frequency of the induction motor, which is in a sticky state unless all wheels are idling, and corresponds to the speed of the electric vehicle (fourth signal).
It can be seen that the rotation frequency signal does not correspond to the speed of the electric vehicle and shows a value that is higher by the amount of the idle speed, as shown in ◎ for 1 hour when all axes idle at times ( and ■) in the figure.

By the way, the amount of change Δf of the rotational frequency signal of the induction motor in a sticky state for each predetermined calculation cycle is a value equivalent to the acceleration of the electric vehicle with respect to the driving force and running resistance, and is a calculation that is performed in a relatively short time. If there is very little variation in running resistance during the cycle and there is no change in the driving force, the rotational frequency signal frB one calculation cycle before and its change amount ΔfrcfrB-fr^)
The rotational frequency signal f at time ◎ is obtained by adding
rc can be estimated, and even if all axes are idling, the reference rotation frequency signal f ro corresponding to the speed of the electric vehicle can be estimated.
can be detected. In addition, as shown in waveform (3) in Fig. 4, when the driving force changes due to a driving command, etc. (time ■), the amount of change ΔJ of the rotational frequency signal one calculation period before
It is necessary to correct the deviation of acceleration corresponding to the change in driving force from , . For this reason, an acceleration/deceleration pattern generator is provided that displays the acceleration/deceleration of the electric vehicle based on driving commands, etc., and a rotational frequency deviation value Δ corresponding to the change in acceleration/deceleration is provided.
f, and correct the amount of change Δfr in the rotational frequency signal and add it to the rotational frequency signal fro from one calculation period before, thereby also detecting the reference rotational frequency signal fro at the time corresponding to the speed of the electric vehicle. I can do it.

The present invention takes advantage of this point, and detects the rotation speeds detected from a plurality of induction motors energized by an inverter, and selects the minimum value during power running and the maximum value during regeneration to increase the rotation frequency. In addition to outputting a signal, a frequency deviation value corresponding to the change in acceleration/deceleration from the acceleration/deceleration pattern of the electric vehicle determined based on the reference rotation frequency signal detected at each predetermined calculation cycle, the amount of change over time, and the driving command. are determined and combined additively to create a signal corresponding to the rotational frequency of the adhesive shaft corresponding to the speed of the electric vehicle, and the output frequency of the inverter is controlled based on the reference rotational frequency signal corrected by these signals. Therefore, even if all shafts idle and the rotational frequency signal detected from the rotational speed of the induction motor increases, a reference rotational frequency signal corrected by a signal corresponding to the rotational frequency of the sticky shaft is obtained, and the output frequency of the inverter is always Since it is controlled to a value that corresponds to the speed of the vehicle, it will not cause a large spin, and when the adhesion between the wheel rails improves, it will automatically start re-adhering, improving adhesion performance. .

The above operation explanation is for when the engine is idling, but
It can be seen that high adhesion control is also possible for the sliding phenomenon during regeneration.

【Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram showing one embodiment of an electric vehicle control device according to the present invention, and a description thereof will be omitted. The difference between this embodiment and the conventional method shown in FIG. 3 is that the slip frequency pattern signal fsF is generated based on the driving command.

Current pattern signal Ip and acceleration/deceleration pattern signal α, (
A pattern generator for generating βF) is provided, and the rotational frequency signal fr obtained from the frequency calculation unit 8 and the acceleration/deceleration pattern signal αP(βF) are input to generate the rotational frequency signal f of the adhesive shaft. At the same time, the discrimination circuit 22 generates a rotational frequency signal f ram and a signal corresponding to the rotational frequency of the adhesive shaft! Among these, a reference rotational frequency calculating section 16 is provided which determines a low value during power running and a high value during first regeneration and outputs it as a reference rotation frequency signal f ro.

That is, the reference rotation frequency calculation section 16 stores the storage element 17.
18, an arithmetic unit 19, a frequency deviation value arithmetic unit 20, an adder/subtractor 21, and a discrimination circuit 22, and the first storage element 17
The reference rotation frequency signal f rol from one calculation period ago is
The second storage element 18 further stores the reference rotation frequency signal f r02 of the previous calculation cycle.

The subtracter 19 receives the output f rol of the storage element 17 and the output f rox of the storage element 18, and outputs a time change amount Δf. Further, the frequency deviation value calculator 20 receives an acceleration/deceleration pattern signal αP (βF) based on the driving command from the pattern generator 15, and receives a frequency deviation value corresponding to the amount of change from the acceleration/deceleration one calculation period before. Δf is calculated and output.

The adder/subtracter 21 receives the output signal frOL* of the storage element 17.
The time change amount Δf, which is the output signal of the calculator 19, and the frequency deviation value Δf, which is the output of the frequency deviation value calculator 20, are inputted and additively combined to create a signal f corresponding to the rotational frequency of the adhesive shaft. be done.

The rotational frequency equivalent signal jr of the adhesive shaft created by this procedure is the rotational frequency signal f0 detected from the rotational speed of the plurality of induction motors 68 to 6D, which is the output of the frequency calculation section 8.
It is input to the discrimination circuit 22 along with the low value 2.
During regeneration, a high value is selected and the reference rotation frequency signal f r
o, and the addition/subtraction high force frequency is controlled. Note that the reference rotational frequency signal j' ro is guided to the first storage element 17 and stored therein, but the data stored in the first storage element 17 is transferred to the second storage element 18, and the data is stored in the first storage element 17. The configuration is such that new data is stored and prepared for the first calculation.

If all the axles of the electric vehicle driven by the induction motors 6A to 6D are in a sticky state, or if there is even one wheel in a sticky state, the rotation frequency signal detected by the frequency calculation unit 8 Both frlI and the adhesive shaft rotation frequency equivalent signal f show the same value.

Since the reference frequency signal f ro corresponding to the speed of the electric car is output, the output frequency of the inverter 5 is also maintained at a frequency corresponding to the speed of the electric car, so that the torque of the induction motor of the idling shaft is reduced by the rotation accompanying the idling. As the number increases, it decreases rapidly and automatically leads to readhesion.

In addition, when all axes are idling, the rotation frequency signal f0 shows a high frequency due to the increase in the number of rotations due to idling, but the rotation frequency equivalent signal Jr of the adhesive shaft is the reference rotation frequency signal before idling and its time change. Since it is calculated based on the amount etc., it shows a low frequency, and the discrimination circuit 22 outputs this signal as the reference rotation frequency signal f ro. Therefore,
Even if all axes slip (slide), the output frequency of the inverter 5 is maintained at a frequency that corresponds to the speed of the electric vehicle, so large slips do not occur and all axes automatically re-stick. effective.

According to this embodiment, even if all axes slip or skid, the slip speed can be suppressed to a minute value, so the adhesion performance is significantly improved and high acceleration/deceleration and high adhesion operation becomes possible. In addition, it is expected to reduce the number of electric vehicles in trains, which will have a large economic effect, and compared to conventional methods, the change in torque during slipping and skidding will be reduced, improving riding comfort.

FIG. 2 shows another embodiment of the present invention. What differs from FIG. 1 is that the method of calculating the time variation Δf of the reference rotational frequency signal f ro has been changed. The amount of change over time of the reference rotation frequency signal f ro for each calculation cycle is detected by the differential element 23, and sequentially stored in the storage element 24 having a plurality of storage sections 24A to 24D, and the average value calculation is performed on these stored results. Averaged by element 25, reference rotation frequency signal f
The amount of change in ro over time is assumed to be Δfr. The data in each of the storage units 24A to 24D of the storage element 24 is sequentially transferred every calculation cycle, and the latest data is always stored in the storage unit 24A.

In addition to the effects of the embodiment shown in FIG. 1, this embodiment has the advantage of preventing rapid fluctuations in the rotational frequency caused by vibrations of the electric vehicle and performing stable frequency control.

〔Effect of the invention〕

According to the present invention, an induction motor-type electric vehicle control device with excellent adhesive performance can be provided, and high acceleration/deceleration operation is possible. In addition, it is expected to reduce the number of electric vehicles in trains, which will have a large economic effect, and it will also improve ride comfort because there will be less torque change when spinning or skidding.

[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. 3 is a control block diagram showing a conventional example, and FIG. 4 is a waveform diagram explaining the operation of each rotation frequency signal, etc. 5... Inverter, 6A-6D... Induction motor, 8
...Frequency calculation section, 14.15...Pattern generator, Fig. 2

Claims (1)

[Scope of Claims] 1. In an electric vehicle equipped with an inverter connected to a power source and a plurality of induction motors driven by the output of the inverter, a reference rotation frequency signal necessary for frequency control of the inverter, The rotation speeds of the plurality of induction motors are detected, and the minimum value during power running and the maximum value during regeneration are selected, and the reference rotation frequency signal and its time variation and frequency deviation value of the acceleration/deceleration pattern are determined for each predetermined calculation cycle. An electric vehicle control device characterized in that the output frequency of the inverter is controlled based on a reference rotation speed signal corrected by detecting a signal corresponding to the rotation frequency of the adhesive shaft. 2. In claim 1, the signal corresponding to the rotational frequency of the adhesive shaft is an additive combination of the reference rotational frequency signal from one calculation period before and its time change amount, and the frequency deviation value of the acceleration/deceleration pattern in the calculation period. The lower value during power running and the higher value during regeneration are determined between the rotational frequency equivalent signal of the adhesive shaft calculated by the calculation and the rotational frequency signal detected and selected from the rotational speed of the plurality of induction motors, and the reference rotational frequency is determined. Electric vehicle control device used as a signal. 3. The electric vehicle control device according to claim 1 or 2, wherein the amount of change over time of the reference rotation frequency signal is an average value of a plurality of amounts of time change stored at each predetermined calculation cycle.