JPH0542202B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a driving electric motor used as a power source for an electric vehicle.

As a power source for an electric vehicle, an electric motor device whose rotational speed is freely controlled by, for example, chopper control is used. FIG. 1 shows an example of this motor control circuit, in which a driving motor 13 is connected to a battery power source 11 mounted on an automobile via a chopper 12 made of, for example, a thyristor or a power transistor. And Chiyotsupa 1
By controlling the gate of 2, the electric motor 13
The electric power supplied to the vehicle is controlled so that the driving operation of the vehicle is controlled. In this case, the electric motor 13
A fuse 14 as a safety device for limiting overcurrent is connected in series to the power supply circuit.

However, in the control circuit of the electric motor 13 configured in this way, if the fuse 14 blows out or the chopper 12 is destroyed for some reason, the electric motor 13 becomes inoperable, and the motor 13 becomes inoperable. Evacuation becomes difficult.

Therefore, it has been considered to use a multiphase multiplex chopper as shown in FIG. 2 as a control means for the electric motor for driving such an automobile. That is, a plurality of power transistors 15a, 15b, . . . are provided in parallel between the electric motor 13 and the battery power source 11, and the transistors 15a, 15b, .
Each base is configured to be controlled by a phase control means (not shown). In the figure, 16a, 1
6b, . . . are reactors provided for each phase, and 17a, 17b, . . . are freewheel diodes.

With this configuration, even if the power transistor of one of the multiple phases breaks down for some reason, the motor 13 can be driven and controlled by the remaining phases. However, in such a case where a certain phase is destroyed, overload is applied to the remaining phases, and there is a possibility that the power transistors of the remaining phases will be destroyed one after another.

This invention was made in view of the above points, and even if, for example, a failure occurs in a part of the control unit using a multiphase multiplex chopper for the electric motor, the electric motor can be reliably driven and controlled, thereby improving the efficiency of the automobile. It is an object of the present invention to provide a driving electric motor control device for an electric vehicle that ensures a running state.

That is, the traction motor control device according to the present invention is provided with a plurality of switch elements corresponding to each phase constituting the multi-phase multiple chopper of the traction motor, so that the amount of current flowing through each of the phases is controlled by a plurality of currents. Detected by each detector. Then, based on the detected current from each of the current detectors, the switch elements are phase-distributed so that the energizing current of each of the switch elements of each phase is set to be equal to or less than the allowable current of the switch element of each phase. In addition, when a phase with an abnormality is detected based on the detected current of each phase, the energization time of each switch element of the remaining phases is made longer than the energization time of each switch element before the abnormality was detected. At the same time, the phase difference between each phase is set to be larger than that before detection, and conduction control is performed by distributing the phase of only each switch element of the remaining phases.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 3 shows its circuit configuration. As in the case of FIG. 2, the motor 13 has power transistors 15a, 15b, . . . which serve as switch elements.
controlled by a polyphase multiple chopper. And this power transistor 1 of each phase
5a, 15b, ... Fuses 14a, 14b, . . . are installed in each circuit as a safety device to limit overcurrent.
...connect in series.

A current detector 18a, 18b, . . . is provided in each phase circuit corresponding to the power transistors 15a, 15b, . . . to detect the current flowing in each phase. Further, base signals from base signal generators 22a, 22b, . . . are supplied to the bases of these power transistors 15a, 15b, . Then, a command from the phase distribution controller 23 is given. In this phase distribution controller 23, current detectors 18a, 18b, . . .
Based on the detection signals from each, it detects the occurrence of an accident such as the destruction of a transistor in a certain phase of a multiphase multiplex chopper or the melting of a fuse. The phase is divided by the number of remaining phases excluding the phase, and the chopper is operated as a multiple chopper according to the number of divided phases. In addition, in this phase distribution controller 23, when the current flowing through the power transistors 15a, 15b, . power transistors 15a, 15b,...
Control can also be performed to protect each from overcurrent.

That is, if the power transistor of one phase is destroyed or the fuse is blown for some reason, the electric motor 13 is driven by the remaining phase, and the car is able to make an evacuation drive. Ru. In this case, a large current flows through the power transistors of the remaining phases, but this overcurrent condition is detected for each phase, and the base signal of the power transistor of that phase is controlled. It can be controlled so that a state is set in which only a current less than the capacity flows.

However, more effective control can be achieved not only by setting the maximum current value in each phase for protection, but also by configuring a multiphase multiple chopper using a plurality of remaining normal phases.

That is, in this embodiment, the capabilities of the transistors, etc. of the remaining plural phases, which are not damaged, are brought out to the maximum, and the moving operation of the automobile is made possible. In this case, by driving the abnormality detection display 24 in response to the detection of a failure in the phase distribution controller 23, the driver's seat can be reliably notified of the occurrence of a failure such as a blown fuse.

Figure 4 shows the state of the operating waveforms when the above embodiment device is made into a three-phase triple chopper, and shows the states of the respective currents i1, i2, and i3 flowing through the three-phase power transistors. . i0 is electric motor 1
3 is the drive current added to the drive current.

In such a device, if the first set of transistors of the three-phase triple chopper is destroyed and the transistor current i1 stops flowing, the phase distribution controller 23 detects this. As shown in FIG. 5, only the second and third sets of transistor circuits are used to operate as a two-phase double chopper.

In other words, the phase difference between the remaining phases is set to be longer than before the destruction of the transistor of one phase is detected, and the energization time of each phase is controlled to be longer. Therefore, multiple chopper operation is performed, and the operation can be switched to two-phase double chopper operation.

As described above, according to the driving electric motor control device according to the present invention, when controlling the electric motor using a multiphase multiple chopper, even if a failure occurs in one of the phases, the electric motor is still controlled to be driven. As a result, the spread of failures to other phases can be effectively prevented. In particular, it performs chopply control using healthy phases that are not experiencing any failures, so it can perform the best operation control in situations where one phase is destroyed, and can be effectively applied as a motor control device as a power source for automobiles. It is considered possible.

[Brief explanation of the drawing]

1 and 2 are circuit diagrams explaining a conventional motor control device, FIG. 3 is a circuit diagram explaining a motor control device according to an embodiment of the present invention, and FIGS. 4 and 5 Each figure is an operation waveform diagram illustrating the state of the control current in the above embodiment. 11...Battery power supply, 13...Electric motor, 14a,
14b, ... fuse, 15a, 15b, ... power transistor, 18a, 18b, ... current detector, 22a, 22b, ... base signal generator,
23... Phase distribution controller.

Claims (1)

[Scope of Claims] 1. A plurality of switch elements provided corresponding to each phase constituting a multi-phase multiple chopper of a traveling electric motor, and a plurality of current detectors that detect the amount of current flowing through each of the phases. , Based on the detected current from each of the current detectors, the phase distribution of the switch elements is performed so that the current flowing through each of the switch elements of each phase is set to be equal to or less than the allowable current of the switch element of each phase. In addition, when a phase with an abnormality is detected based on the detected current of each phase, the energization time of each switch element of the remaining phases is set to be longer than the energization time of each switch element before the abnormality was detected. and a control means for setting the phase difference between each phase to be larger than before the abnormality detection, and controlling conduction by distributing the phase of only each switch element of the remaining phases. Control device.