JPH0739005A - Power converter for electric car - Google Patents

Abstract

PURPOSE:To prevent induction problems by selecting a switching frequency that does not interfere with the frequency of a signal device. CONSTITUTION:Of two or more signal devices 11a-11n that transmit signals to ground equipment, those in operation output '1' and those not in operation output '0' to a frequency set-point adjuster 12. A signal detector 13 of the frequency set-point adjuster 12 detects such signals. A frequency memory 14 that stores, in advance, frequencies other than multiple integer or inverse number of integer of, the frequencies used for signal devices, as switching frequencies, selects a corresponding switching frequency. A gate controller 15 controls the opening/closing operation of a switching element constituting an inverter 6 with the corresponding switching frequency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power conversion device for an electric vehicle.

[0002]

2. Description of the Related Art In railway vehicles, signal devices such as train detection devices for railroad crossings, automatic train stop devices (ATS devices), speed control devices used for automatic train control devices (ATC devices), etc. Signals are transmitted by children and ground children. Since the signal level used for this signal transmission is weak, it is easily affected by induced noise and return current generated from vehicle electrical components mounted on the vehicle when the vehicle travels. In particular, in order to supply AC power to vehicle electrical products, an inverter device is provided for converting DC power supplied from an overhead wire into AC power.
If the switching frequency of the switching element constituting the switching device interferes with the frequency used for signal transmission of the signal equipment, the signal equipment may malfunction.

Therefore, in order to prevent such inductive damage, a filter circuit for removing a component of the switching frequency that interferes with the operating frequency of the signal equipment is conventionally provided,
Shielding the input / output lines, or the actual Kaihei 4-3909
As described in No. 2, measures were taken to store each switching element of each phase of the inverter device in a split case made of a magnetic material.

[0004]

However, in the above-mentioned conventional technique, in order to prevent the inductive obstacle, the input line is shielded or the box itself for accommodating the inverter device is devised structurally. Along with the change, the power supply (main circuit part) that supplies alternating-current power to the electric parts for the vehicle is subject to the change, resulting in a large overhang, resulting in a large loss both economically and temporally. In addition, in recent years, mutual railroad connections between individual railway companies have become common, and since the signal equipment used differs depending on the travel section, the operating frequency also differs. There was a problem that it had to be changed accordingly.

Therefore, the present invention eliminates the above-mentioned problems and provides an electric power converter for an electric vehicle which prevents the switching frequency of the inverter device and the operating frequency of the signal device from interfering with each other to cause an induction failure. With the goal.

[0006]

In order to achieve the above object, in the invention according to claim 1, a signal device mounted under the floor of a vehicle for performing signal transmission with a ground device, and used for signal transmission of this signal device. Frequency setter that sets an integer multiple of the specified frequency or a frequency other than an integer fraction as the switching frequency, and DC power that is composed of multiple switching elements as input, and is switched by the switching frequency set by the frequency setter. And an inverter device for opening and closing the element to convert DC power into AC power. In the invention according to claim 2, a plurality of signal devices mounted under the floor of the vehicle for transmitting signals corresponding to a plurality of ground devices respectively, and used for signal transmission between the ground devices of these signal devices. A frequency setting device that stores an integer multiple of the frequency of the above or a frequency other than an integer fraction as the switching frequency and switches the switching frequency according to the signal equipment that is transmitting the signal, and a plurality of switching elements. Configured with DC power as input,
Depending on the switching frequency set by the frequency setting device,
And an inverter device for opening and closing a switching element to convert DC power into AC power.

[0007]

With the above construction, in the invention according to the first aspect, a frequency other than an integral multiple or a fraction of the operating frequency of the signal equipment is preset as the switching frequency of the inverter device by the frequency setting device. . Since the switching frequency interferes with an integral multiple or a fraction of the operating frequency of the signal equipment to cause an induction failure, the inverter device is operated with a switching frequency other than a frequency that interferes with the operating frequency. According to the second aspect of the present invention, when a plurality of signal equipments perform signal transmission with the corresponding ground equipments, the frequency setter switches in advance a frequency other than an integral multiple or a fraction of the operating frequency of each signal equipment. It is stored as a frequency, and the switching frequency is switched according to the operating signal equipment. Therefore, if the operating signaling device changes depending on the traveling section, the switching frequency also changes. By operating the inverter device at this switching frequency, it is possible to prevent inductive interference without interfering with the operating frequency of the signal equipment.

[0008]

Embodiments of the present invention will be described in detail with reference to the drawings. 1 and 2 are views showing an embodiment of the present invention, FIG. 1 is a configuration diagram of a power conversion device for an electric vehicle, and FIG. 2 is a schematic diagram of the vehicle. The direct current flowing through the overhead wire 1 is collected by the pantograph 2 and supplied to the inverter device 6 via the contactor 3, the filter reactor 4, and the filter capacitor 5. In the inverter device 6, a DC current is converted into a three-phase AC current, and the three-phase AC current is supplied to the load 10 via the AC filter reactor 7, the AC filter capacitor 8 and the converter 9. The inverter device 6 is composed of a plurality of switching elements, and the switching frequency of each switching element is variable as described below.

Under the floor of the vehicle, signal devices 11a to 11n (see FIG. 2)
In the figure, 11a and 11b are shown, and the rest are omitted). These signal devices 11a to 11n are transmitting signals to the ground, and the devices used in each section are different. From the signal devices 11a to 11n, a digital signal of "1" is being output to the frequency setting unit 12 when the signal is being transmitted to the ground and is "0" when the signal is not being transmitted. The frequency setting device 12 includes a signal detection unit 13 that detects digital signals from the signal devices 11a to 11n, and a frequency storage unit 14 that stores a switching frequency that does not interfere with the frequencies used by the signal devices 11a to 11n. ing. First, the signal detector 13
Then, when a digital signal from the signal equipment 11a to 11n is detected, an operation signal indicating which signal equipment is operating is output to the frequency storage unit 14. Then, the frequency storage unit 14 receives the operation signal and selects a switching frequency that does not interfere with the signal equipment being used, and the gate control unit 15
The switching frequency of the navel is output. Then, the gate control unit 15 performs on / off control for the plurality of switching elements forming the inverter device 6 according to the switching frequency. The operation signal output from the signal detection unit 13 is, for example, a signal in which the signal device 11a has lower bits and the signal device 11n has higher bits.
The frequencies used by the signal devices 11a to 11n are predetermined depending on the route. The frequency that interferes with the used frequency is an integral multiple of the used frequency, that is, an integer. Since the normal switching frequency is 2.7 KHz to 4.5 KHz, a frequency avoiding a frequency that interferes with the above-mentioned used frequency within this range is stored in the frequency storage unit 14 in advance.

For example, as shown in FIG.
A case of traveling in two sections A and B using a and 11b will be described. It is assumed that the frequency used by the signal equipment 11a is fa and the frequency used by the signal equipment is fb. While the vehicle is traveling in the section A, the signal equipment 11a is used, and the ground equipment and the signal transmission are conducted at the frequency f.
It is done in a. The signal device 11b is not used.
At this time, the signal device 11a outputs “1” to the frequency setting device 12, and the signal device 11b outputs the frequency setting device 12.
“0” is output for First, in the signal detection unit 13,
Upon receiving the digital signals from the signal devices 11a and 11b, an operation signal (for example, 01 in this case) is output to the frequency storage unit 14. The frequency storage unit 14 receives the operation signal and selects the switching frequency fa ^* that does not interfere with the use frequency fa of the signal equipment 11a. This switching frequency fa ^* is an integral multiple of the use frequency fa or an integer fraction (n
fa, fa / n: where n is an integer). Then, the switching frequency fa ^* is output from the frequency storage unit 14, and the gate control unit 15 controls the switching element of the inverter device 6. Next, when the vehicle enters the section A from the section B, the operation of the signal equipment 11a is stopped, and the signal equipment 11a is stopped.
b performs signal transmission with the ground equipment at the frequency fb. Then,
The signal device 11a outputs "0" to the frequency setting device 12, and the signal device 11b outputs "1" to the frequency setting device 12. In the signal detection unit 13, the signal device 11
It receives the digital signals from a and 11b and outputs an operation signal (for example, 10 in this case) to the frequency storage unit 14. That is, as the operation signal, when the operation signal (01) output while traveling in the section A enters the section B, the operation signal (10)
Will change to. The frequency storage unit 14 detects this operation signal and selects the switching frequency fb ^* that does not interfere with the operating frequency fb of the signal equipment 11b. The switching frequency fb ^* is a frequency that avoids an integral multiple of the operating frequency fb or a fraction of an integer (nfa, fa / n: n is an integer). From the frequency storage unit 14, the switching frequency fb
^* Is output, and the gate controller 15 controls the switching element of the inverter device 6. In other words, the vehicle is section A
When traveling from section B to section B, the frequency setting unit 13 sets a switching frequency fa ^* that does not interfere with the operating frequency fa of the signal equipment 11a while traveling in section A. The fa ^* is set to the switching frequency fb ^* that does not interfere with the operating frequency fb of the signaling device 11b. For example, fa = 60 [H
z], fb = 200 [KHz] and the switching frequency is near 3 [KHz], fa ^* = 3.1 [KHz]
], Fb ^* = 3.0 [KHz]. Therefore, since the switching element of the inverter device 6 is operated at a frequency that does not interfere with the frequency used by the signal equipment, inductive interference can be prevented.

In the above example, the case where the signal equipments operate individually has been explained. However, when a plurality of signal equipments operate in one section, an integral multiple or an integral part of the least common multiple of the signal frequencies of those signal equipments. It suffices to set a frequency that avoids 1. Also, when one signal device uses a plurality of signal frequencies, the frequency may be set so as to avoid an integral multiple or an integer fraction of the least common multiple of the plurality of signal devices.

[0012]

As described above, according to the present invention, the switching frequency is switched to a frequency that does not interfere with the preset operating frequency of the signal equipment when receiving the operation signal of the signal equipment mounted on the vehicle. As a result, the inverter device is operated, so that it is possible to prevent the occurrence of inductive obstacles without structural changes.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a power conversion device for an electric vehicle showing an embodiment of the present invention.

FIG. 2 is a schematic diagram of a vehicle.

[Explanation of symbols]

 6 Inverter device 11a to 11n Signal device 12 Frequency setting device 13 Signal detection unit 14 Frequency storage unit 15 Gate control unit

Claims (2)

[Claims] 1. A signal device mounted under the floor of a vehicle for transmitting a signal to a ground device, and a frequency other than an integral multiple or a fraction of the frequency used for signal transmission of the signal device is set as a switching frequency. And an inverter for converting the DC power into AC power by opening and closing the switching element at a switching frequency set by the frequency setter, the DC power being composed of a frequency setter and a plurality of switching elements. -A power conversion device for an electric vehicle having a power device. 2. A plurality of signal devices that are mounted under the floor of a vehicle and perform signal transmission corresponding to a plurality of ground devices, respectively, and a plurality of signal frequencies of those signal devices used for signal transmission to the ground devices. A frequency setting device that stores a frequency other than an integral multiple or a fraction of an integer as a switching frequency and that sets the switching frequency by switching according to the signal device that is transmitting the signal, and a plurality of switching elements A DC power input, and an inverter device for converting the DC power into AC power by opening / closing the switching element at a switching frequency set by the frequency setting device. .