JPH0224081B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric vehicle control device in which open-phase detection does not operate even during low-speed regeneration in regenerative brake control of a multi-phase single chopper control device.

The multi-phase single chopper system is a system that performs chopper operation of two or more phases from the power source's perspective, and one-phase chopper operation from the motor's perspective. 1st
The figure shows a general example of a two-phase single chopper regenerative brake circuit. In this figure 1, pan is a pantograph, LF is a filter reactor, CF is a filter capacitor, DF1 and DF2 are reverse blocking diodes,
CH1 and CH2 are chopper devices, MSL1 and MSL2 are main smoothing reactors, F1 and F2 are motor field windings, A1 and A2 are motor armatures, DCCT ₁ ,
DCCT ₂ indicates a DC current transformer that detects the main circuit current.

In this system, the circuits are independent for each phase, so the rise characteristics of the motor current may differ, especially during low-speed regenerative braking, due to differences in motor characteristics, circuit impedance, etc. In some cases, the current may rise in only one phase, and the current may not rise in the other phases.

On the other hand, in a multi-phase single chopper, if the current in one or more phases does not rise, the current ripple flowing through the overhead wire becomes large, and there is a risk of so-called inductive failure, which adversely affects the signal circuit on the track. Conceivable.

To prevent this, a protection circuit is usually provided that shuts off the circuit when the current difference between the phases exceeds a certain value. The block diagram is the second one.
As shown in the figure.

In FIG _. 2, the output of the absolute value detection circuit 1 that detects the absolute value of the difference between the currents I ₁ and I ₂ is compared with the reference value _{I 0 and} the output of the absolute value detection circuit 1 is ｜I ₁
It is comprised of a current detection circuit 2 that detects an open phase and turns off the circuit when -I ₂ | exceeds a reference value I ₀ .

Furthermore, when using regenerative braking, a circuit is usually provided to detect whether or not the regenerative braking is activated. Its block diagram is shown in FIG. In this Figure 3, the output Imax of the maximum value detection circuit 3 that detects the maximum values of currents I ₁ and I ₂ and the reference value
The current detection circuit 4 compares _I0 and outputs an output when the output Imax exceeds the reference value _I0 .

SUMMARY OF THE INVENTION In view of the above points, an object of the present invention is to provide an electric vehicle control device that can simplify the detection circuit used in a normal chopper device into a single circuit.

Embodiments of the electric vehicle control device of the present invention will be described below with reference to the drawings. FIG. 4 is a block diagram of a current detection circuit of a multi-phase single chopper in an electric vehicle control device in one embodiment.

In FIG. 4, DCCT ₁ and DCCT ₂ are DC current transformers in the main circuit of the electric vehicle control device, respectively, as _shown in FIG _. Detects the main circuit current and outputs the detected currents I ₁ and I ₂ to the minimum value detection circuit 5.
It is now being sent to

The minimum value detection circuit 5 receives the output currents I ₁ and I ₂ , detects the minimum value Imin of the output currents I ₁ and I ₂ , and sends the output to the comparison section 6 .

The minimum value Imin and the reference value I ₀ are added to the comparison unit 6, which is composed of a comparator and outputs an output when I _nio ≧I ₀ .
Current detection circuit 4 detects current. This current detection circuit 4 is the same as the current detection circuit shown in FIG.

Next, the operation of the electric vehicle control device of the present invention will be explained. In this Fig. 4, if the detection current I ₁ of the DC current transformer DCCT ₁ does not flow,
The output Imin of the minimum value detection circuit 5 becomes 0, and the current detection circuit 4 does not output any output. In other words, in this circuit, it is assumed that the regenerative brake has not been applied and the circuit is immediately disconnected, eliminating the possibility that current will flow in only one phase and cause an induction failure.

In the conventional systems shown in Figures 2 and 3, in the same situation, the circuit in Figure 3 assumes that the regenerative brake is working and is not turned off, but in the circuit in Figure 2, the absolute value difference circuit 1 Output current | I ₁ − I ₂ | is the reference value
I becomes larger than ₀ and the circuit is eventually turned off.

Also, when the output current I ₂ of the DC transformer DCCT ₂ does not flow, the circuit is turned off in the same way as above. Furthermore, if both of the detection currents I ₁ and I ₂ of the DC transformers DCCT ₁ and T ₂ do not flow, I ₁ = I ₂ = I _nio = 0 and I _nio < I in Fig. 4. Since it becomes ₀ , the current detection circuit 4 does not output an output and the circuit is turned off. In the conventional systems shown in FIGS. 2 and 3, the circuit shown in FIG. 3 is turned off because the output Imax of the maximum value detection circuit 3 does not reach the reference value _I0 .

Furthermore, when the output currents I ₁ and I ₂ of both the DC current transformers DCCT ₁ and DCCT ₂ flow, as shown in FIG. However, in the conventional methods shown in FIGS. 2 and 3, the output current |I ₁ −I ₂ | of the absolute value difference circuit 1 of the circuit shown in FIG. 2 is the reference value.
I is smaller than ₀ , and in the circuit shown in Figure 3, it is assumed that the regenerative brake is working, and the circuit is not turned off.

As described above, according to the electric vehicle control device of the present invention, the output current from each DC transformer that detects the current for each phase in the regenerative brake circuit of the electric vehicle control device is input to the minimum value detection circuit. The minimum value detection circuit detects the minimum value of each phase current, and the current detection circuit detects when the result of comparing the detected value with the reference value exceeds the reference value, so the conventional two circuits In contrast, the present invention has the advantage of consolidating the functions of the two conventional circuits and simplifying the circuit configuration.

[Brief explanation of drawings]

Figure 1 is a circuit diagram showing a general example of a regenerative brake circuit for a two-phase single chopper, Figure 2 is a block diagram of a conventional two-phase single chopper one-side circuit failure detection circuit, and Figure 3 is a conventional regenerative brake circuit. Block Diagram of Circuit Configuration Detection Circuit FIG. 4 is a block diagram of the current detection circuit portion of a multi-phase single chopper in an embodiment of the electric vehicle control device of the present invention. DCCT ₁ , DCCT ₂ ... DC current transformer, 4 ... Current detection circuit, 5 ... Minimum value detection circuit, 6 ... Comparison section. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In a multi-phase single chopper control device that controls two or more DC motors, the output current from the DC transformer for each phase that detects the current of each phase is input, and the minimum value of the current of each phase is calculated. A minimum value detection circuit for detecting the minimum value, a comparison section for comparing the minimum value with a reference value, and a current detection circuit for cutting off the DC motor circuit when the minimum value falls below the reference value. An electric vehicle control device featuring: