JPH0223002A - Power source equipment for car - Google Patents

Abstract

PURPOSE:To prevent flow out of higher harmonics to a stringing reliably even under continuous abnormal conducting state of a voltage clipper circuit by detecting continuous current flow through the voltage clipper circuit for longer than a predetermined time and stopping the operation of a power source. CONSTITUTION:Power is received from a stringing 2 through a pantograph 1 and fed through a power source switch 4 and a filter circuit 5 to a power source 3. When power is supplied to the power source 3, the filter circuit 5 prevents flow out of higher harmonics produced through switching operation to the stringing 2. When overvoltage appears at the terminal of a capacitor 7, a voltage clipper circuit 11 operates a thyristor 10 to suppress voltage rise. When the voltage clipper circuit enters into continuous abnormal conducting state and the detection signal of a current detector 12 continues for a predetermined time, a control circuit 13 stops operation of the power source 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle power supply device that receives power from an overhead wire via a pantograph and supplies the received power to various loads in a vehicle.

[Conventional technology]

FIG. 2 is a block diagram showing a conventional vehicle power supply device. In FIG. 2, 1 is a pantograph that receives power from an overhead wire 2; 3 is a pantograph that receives power from the pantograph 1;
Input via the power switch 4 and filter circuit 5,
It is a power source that supplies power to various loads (not shown) in the vehicle.
The filter circuit 5 is composed of a reactor 6 and a capacitor 7. 8 and 9 are resistors connected in series with each other and connected in parallel with the reactor 6; 10 is a thyristor connected in parallel with the reactor 6;
The gate 10G of 0 is connected to the connection point P between the resistors 8 and 9. Here, the resistors 8 and 9 and the thyristor 10 constitute a voltage clipper circuit 11.

Next, the operation will be explained. The received power received from the overhead wire 2 via the pantograph 1 is input to the power source 3 via the power switch 4 and the filter circuit 5, and is supplied from the power source 3 to various loads in the vehicle.

During this power supply, the filter circuit 5 prevents harmonics generated by the switching operation of the power supply 3 from flowing into the overhead wire 2 .

However, since this filter circuit 5 is composed of a reactor 6 and a capacitor 7, LC resonance occurs when the power is turned on, and an overvoltage occurs.

Therefore, in order to prevent this overvoltage, a voltage clipper circuit 11 is provided in parallel with the reactor 6.

The thyristor 10 of this voltage clipper circuit 11 normally operates only instantaneously when the power is turned on, but due to some kind of malfunction, the thyristor may become continuously in an abnormal conduction state, and if this conduction state continues, the high frequency 10 from the power supply 3 to the overhead wire 2, and has an adverse effect on traffic lights and the like (not shown) connected to the overhead wire 2.

[Problem to be solved by the invention]

Conventional power supply devices for vehicles are configured as described above, so when the voltage clipper circuit becomes in a continuous abnormal conduction state, harmonics flow from the power supply to the overhead wires and have a negative impact on traffic lights, etc. there were.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a vehicle power supply device that can reliably prevent harmonics from flowing out to overhead wires.

[Means to solve the problem]

The vehicle power supply device according to the present invention includes a filter circuit provided on the input side of the power supply, a voltage clipper circuit connected in parallel with a reactor constituting the filter circuit, and a current that continues to flow through the voltage clipper circuit for a certain period of time or more. The device is equipped with a control circuit that detects the flow and stops the operation of the power supply.

[Effect]

The control circuit according to the present invention detects that current has continued to flow through the voltage clipper circuit for a certain period of time or more and stops the operation of the power supply, even if the voltage clipper circuit is in a continuous abnormal conduction state.

Reliably prevent harmonics from leaking into overhead wires.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 12 is a current detector that detects the current of the voltage clipper circuit 11; 13 is a current detector that determines whether current has continued to flow through the voltage clipper circuit 11 for a certain period of time or more based on the detection signal of the current detector 12; This is a control circuit that stops the operation of the power supply 3.

Note that the same parts as in FIG. 2 are designated by the same reference numerals and their explanation will be omitted.

Next, the operation of the above embodiment will be explained. The operation of receiving power from the overhead wire 2 via the pantograph 1 and inputting this received power to the power supply 3, and the reactor 6 that constitutes the filter circuit 5.
In this operation, the terminal voltage of the capacitor 7 constituting the filter circuit 5, that is, the input voltage of the power supply 3, is detected, and the thyristor 10 is instantaneously operated to prevent the voltage from rising. The suppressing operation and the like are the same as the conventional device shown in FIG. 2 above.

When the received power is input to the above type g3, the voltage clipper circuit becomes abnormally conductive continuously due to a failure or the like, and if it continues while there is a detection signal from the current detector 12 that detects the current flowing through the voltage clipper circuit 11, A control circuit 13 which receives this detection signal as input stops the operation of the power supply 3.

〔Effect of the invention〕

As described above, according to the present invention, the abnormal conduction state of the clipper circuit is detected and the operation of the power supply is stopped in the event of an abnormality, so that an abnormal increase in the power input voltage can be suppressed by the clipper circuit, and This has the effect of reliably preventing harmonics from flowing from the power supply to the overhead wires when the clipper circuit fails.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a vehicle power supply device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional vehicle power supply device. 1 is a pantograph, 2 is an overhead wire, 3 is a power source, 4 is a power switch, 5 is a filter circuit, 6 is a reactor, 11 is a voltage clipper circuit, and 13 is a control circuit. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] A power supply that receives power received from an overhead line via a pantograph, a power switch and a filter circuit provided on the input side of the power supply, and a filter circuit when the input terminal voltage of the power supply rises above a specified value. A power supply device for a vehicle having a voltage clipping circuit that short-circuits a reactor of the vehicle, further comprising a control circuit that detects that current has continued to flow through the voltage clipper circuit for a certain period of time or more and stops the operation of the power supply. A vehicle power supply device featuring: