JPH1014300A - Control system-switching system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an electric automobile to travel, even when a sensor fails by switching a vector control to V/F control or sensorless vector control upon the failure of the sensor, thereby driving a motor without using the sensor. SOLUTION: A control system switch 22 is controlled by delivering a sensor failure signal, and a vector control system 23 is switched to a V/F control system 24. Consequently, an inverter 13 is controlled by an inverter control command, without using a sensor, and a motor 4 is driven. According to the system, drive control of an automobile can be performed by V/F control or sensorless vector control without using any sensor, even when the sensor fails or a signal line is disconnected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control system switching device for a motor speed detection failure in a vector control device for an electric vehicle.

[0002]

2. Description of the Related Art In an electric vehicle driving motor, an induction motor (IM) controlled by so-called vector control is used.
Is often used. Here, an outline of the vector control in FIG. 1, divided first primary current is hitting the control on the excitation current I ₀ and the torque current I _t, by controlling independently, fast torque Response and high-precision control are realized. Generally, in order to prevent transient phenomena, vector control is performed with the excitation current I ₀ constant regardless of the operation state, except in special cases such as constant output operation.

[0003] In order to obtain this torque current I _t is calculated by the current command calculation and protection control circuit 2, the brake command for the circuit 2 is accelerator opening command circuit 1a for driving, and braking The circuit is connected to a circuit 1b, and furthermore, each information of a motor temperature, an inverter temperature, and a battery voltage is inputted to perform protection control. Here, one in which the current calculation and protection control circuit 2, and outputs a torque current I _t which is proportional to the accelerator opening per the driving, and outputs a constant excitation current I _0.

[0004] slip frequency calculating unit 3, and the torque current command I _t, the excitation current command I ₀ orthogonal thereto from the induction motor 4 of the secondary time constant tau _2, obtaining the slip frequency omega _s. Speed detector 5 determines the speed detector omega _r indicative of the rotational speed of the induction motor 4.

The slip frequency ω _s is added to the detected speed value ω _r of the induction motor 4 to be converted into a primary angular speed ω. The angular speed ω is integrated by an integration operation unit 6 to obtain a phase angle θ.

[0006] The current control unit 7 a torque current command I _t and excitation current respectively of the torque current with respect to instruction I ₀ detected value I _tFB
And the exciting current detection value after calculation by the proportional integral operation from a deviation between I _0FB, further torque-axis voltage control signal V _t and the excitation axis voltage addition and subtraction to the rotating coordinate interference component of the induction motor machine for both operation result obtaining a control signal V _0.

The torque current detection value _ItFB and the excitation current detection value _I0FB are calculated from the two-phase current detection values of the induction motor 4. In this calculation, the two-phase currents I _U and I _W are converted into digital values by the A / D converter 8, respectively, and the V-phase current detection value I _V is also obtained by adding the two, and the respective current values I _U , I _V , It converted from I _W to the two-phase alternating current of fixed coordinates in three-phase / two-phase converter 9, which converts the torque current detection value I _tFB rotational coordinates and the exciting current detection value I _0FB coordinate transformation unit 10.

The decoupling voltage control signals V _t and V ₀ from the current controller 7 are converted into a primary voltage command V _{1 of} polar coordinates and a phase angle φ by a coordinate converter 11, and further converted to a polar coordinate / three-phase converter 12. The three-phase voltage commands V _U , V
_The signals are converted into V and _{VW and} are used as output voltage control signals of the PWM inverter 13.

The PWM inverter 13 has a three-phase voltage command V
_{According to U} , V _V , and V _W , the DC current of the vehicle-mounted battery B is converted into a three-phase AC current and supplied to the induction motor 4. Thus, the induction motor 4 is driven, and the electric vehicle runs.

[0010]

When the above-described vector control device is mounted on an automobile, for example, when a speed sensor or a magnetic flux sensor breaks down or a signal line connecting these sensors and the controller is disconnected, the characteristics of the automobile are reduced. If the car does not move while stopped, it is inconvenient, and it is desirable to be able to move on its own. The above description is based on the assumption that there is a high possibility that a failure of the sensor or disconnection of the signal line will occur. However, even if the motor controller (inverter) 13 is normal, the motor cannot be moved due to the above-described abnormality. Should be eliminated. For example, in the case of an engine car, even if the engine fails, the starter motor can be used to move on its own, but it is desirable for an electric vehicle to move in the same manner.

The present invention has been made in view of the above problems, and has as its object to provide a control system switching device that can move by itself even if there is a failure in a sensor or the like.

[0012]

The present invention has the following matters specifying the invention. (1) The discriminator includes at least one of a discriminator that obtains a current command signal, a current detection signal, and a speed signal to determine whether or not a sensor has failed, and operating means that obtains a failure signal by operation. A switch is provided for switching the control mode from the vector control mode to another control mode in response to a failure signal from the operating means. (2) In (1), the other control method is a V / F control method or a sensorless vector control method.

Even if there is a sensor failure or disconnection of the signal line, the V / F control and the sensorless vector control do not use the sensor, nor use the signal of the signal line between the sensor and the controller to drive the vehicle. Can control.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to FIGS. In the figure, the same parts as those in FIG. When switching the control method from vector control when a sensor fails, it is necessary to first detect a sensor failure. FIG. 2 shows a sensor failure discriminator 20.
Is connected to the same input as the input of the current control unit 7 shown in FIG. That is, the excitation current I _0, the torque current I _t, the excitation current detection value I _0FB, torque current detection value I _tFB, and speed pulses ω is input. In this sensor failure discriminator 20, the current is flowing according to the command value, that is, the current I ₀ =
An I _0FB, a current I _t = I _tFB, also not less than a set value of the torque current I _t is determined by the vehicle, by satisfying all of the conditions that the vehicle speed ω pulse is input, sensor failure is determined And outputs a sensor failure signal.

A failure signal may be obtained by turning on the sensor failure switch 21 by the driver without providing the discriminator 20 shown in FIG. That is, a failure switch 21 is provided around the driver's seat, and when the vehicle cannot be driven, the driver turns on the switch 21 to output a failure signal. As shown in FIG. 3, after the failure switch 21 is turned on, the control system is switched, the vehicle is driven by the sensor failure, and if the sensor is not failed, the vehicle is stopped.

4 and 5 by sending the sensor failure signal.
As shown in FIG. 5, the control system switch 22 is controlled to switch from the vector control system 23 to the V / F control system 24 in FIG. 4 and to the sensorless vector control system 25 in FIG.

That is, in the V / F control system shown in FIG. 4, instead of the vector control shown in FIG. 1, for example, an inverter control command is transmitted via a V / F pattern circuit 24a, a PWM circuit 24b, and a driver 24c shown in FIG. Is output to drive the motor 4. The inverter 13 is controlled by the command without using a sensor, and the motor 4 is driven.

In the case of the sensorless vector control shown in FIG. 5, the actual speed of the motor 4 is estimated by the same-dimensional magnetic flux observer 25a and the speed adapting mechanism 25b shown in FIG. The secondary magnetic flux of the stator coordinates and the primary current of the motor are designated, and the speed adaptation mechanism 25b uses an error signal obtained by comparing the estimated primary current with the detected primary current using an adaptive adjustment rule to obtain a motor. It is an estimate of the actual speed. Therefore, also in this case, the inverter 13 is controlled by the estimated speed without using a sensor, and the motor 4 is driven. In the sensorless vector control, the controllability change when the parameter changes when the motor temperature changes, that is, the output torque fluctuates because the motor constant cannot be identified when the motor temperature changes, but the other control performance is the same as the vector control with sensor. Has similar controllability.

In the above description, an electric vehicle using an induction motor IM is taken as an example, but a permanent magnet (PM) is used.
Various sensorless control methods have also been proposed for control using the PM. In the same way as described above, by switching to sensorless control when a sensor fails, even an electric vehicle using PM can run at the time of failure.

[0020]

As described above, according to the present invention, the motor can be driven without using a sensor by switching from vector control to V / F control or sensorless vector control in the event of a sensor failure. Is also possible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an outline of vector control.

FIG. 2 is an explanatory diagram of a sensor failure classifier.

FIG. 3 is a flowchart showing a failure input means by a driver and its flowchart.

FIG. 4 is a block diagram of switching to a V / F control method.

FIG. 5 is a block diagram of switching to a sensorless vector control method.

FIG. 6 is a schematic block diagram of V / F control.

FIG. 7 is a schematic block diagram of sensorless vector control.

[Explanation of symbols]

 Reference Signs List 20 sensor failure discriminator 21 sensor failure switch 22 control method switch 23 vector control method 24 V / F control method 25 sensorless vector control method

Claims (2)

[Claims] 1. A discriminator for determining whether a sensor failure has occurred by obtaining a current command signal, a current detection signal, and a speed signal, and operating means for obtaining a failure signal by an operation. A control system switching device, comprising: a switch for switching a control system from a vector control system to another control system in accordance with a failure signal from a device or an operation means. 2. The control system switching device according to claim 1, wherein the other control system is a V / F control system or a sensorless vector control system.