JPS5876332A - Detection of electrical power regenerative operation - Google Patents

Abstract

PURPOSE:To make it possible to surely discriminate whether regenerative operation is carried out in an electrical power regenerative area or not, by detecting the electrical power regenerative operation in a current feeding system of AT current feeding type, through the comparison between the phases of neutral currents at two ATs laid in the electrical power regenerative area. CONSTITUTION:When an electric car 6 is retarded with the use of a regenerative brake during the car running in the section which is between the laid positions 1-2, 1-3 of autotransformers AT and which is continuously inclined downward, regenerative power is obtained upon the entrance of the car into the section. Neutral currents i1, i2 are detected in this stage, by current detectors 7-1, 7-2, and are delivered to a discriminating circuit 9 together with their voltages. The currents of the electrical car 6 upon power running and regenerative running have phase differences between their voltages and currents, that is, the angles of their retarded power factors are different from each other, such as about 40 deg. and 130 deg.-140 deg., and therefore, whether the regenerative operation is carried out or not may be discriminated. Further, an electrical power converter 10 for retrieving electrical power is laid in the vicinity, and its output is connected to a load 11 adapted to consume the regenerative power.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power regeneration operation detection method for detecting that an electric vehicle traveling in an A'l' AC electrified section has entered a power regeneration area.

Regenerative braking may be required to suppress vehicle speed on long downhill slopes in AT-powered AC electrified sections. This regenerative braking is effective because regenerated power is consumed, so the power consumption destination is required. In some cases, the consumption of regenerated power is usually limited to the substation that is the power supply source, or to the same system.

This is because the power converter and the separate system are separated from each other due to the cost of installing power transmission lines, which would be costly if the power converter is located far away from the power converter if it is on a separate system, and to cut off the circulation mt* when there is no power regeneration. It is necessary to communicate intermittently, and a detection signal is required to indicate whether or not regenerative operation is in progress. It cannot be detected from the phase difference between the power regeneration area and signals must be exchanged with the apogee, so even if there is a separate system near the power regeneration area, there is a risk of malfunction due to noise contamination. This is because it is avoided to install a power conversion device for recovering regenerated power in the vicinity of the power regeneration area.

However, if there is a sufficient amount of regenerative power generated and there is another system close to the power regeneration area.

Since it is more economical to supply regenerative power to a separate system, it is desirable to install a power converter for regenerative power recovery near the power regeneration area. Driving) Detection means is required to accurately detect what is happening at that location.

The present invention has been made in view of the above points, and is based on two A' in the power regeneration area or the power regeneration area and its adjacent area.
It is an object of the present invention to provide a method for detecting a power regeneration area that can accurately determine whether regenerative operation is being performed in the power regeneration area by comparing the phases of neutral point currents of l' (autotransformer).

Hereinafter, the method of the present invention will be explained in detail based on the illustrated embodiments.

As shown in Figure 1(a), a section l with an AT power equation
This means that the required number of autotransformers, for example 3 autotransformers 1, are installed at regular intervals.
-1.1-2.1-J is installed and connected between the trolley wire 2 and the electric wire 3, and its neutral point (turns ratio 1
:1, and sometimes an arbitrary turns ratio) is connected to the rail 4. A line 3 connects the trolley line 2.
is connected to the power source 5 at the substation. This AT
It is well known that the feeder power system is effective in alleviating communication interference and reducing and preventing catenary voltage from decreasing.

In a feeding system with such a configuration, ATJ-7°1-2.
1-5 Trolley wire at installation point 2. The voltage across rail 4 is vIs v! +vj, and the current flows through each neutral point. Assuming that these are neutral point currents 11*1ts 1m, the relationship between each neutral point current 11*1t+i and the position of the electric car 6 is as shown in FIG. 1(b).

Now, the application section of the method of the present invention requires the existence of a continuous downward gradient section, and here, ATZ-j.

If the area between 1 and 5 is a continuous downhill slope area, and the electric car 6 is to use regenerative braking to reduce speed when traveling in this area, as the electric car 6 enters the slope area, power regeneration is performed. In this case, the number of trains is small,
And if the power regeneration area is between ATl-2 and ATl-1-J, then the voltage flL1t +1s and the voltage v! *It is possible to determine the presence or absence of regenerative power by comparing the phase difference with vl. For comparison, ATM-z@1l-vl and AT
A method of comparing each power factor angle of 1l-vl on the I-3 side,
Let voltage ma3 represent the % output between A'l'J-2 and 1-3 and %'! A possible method is to compare the power factor angles of VB+F-71.

That is, as shown in FIG. 2, the electric current (5
j! Line arrow) and current during regeneration (dotted line arrow), even though the flow paths are the same, the phase difference between the voltage and current, that is, the delay power factor angle, is approximately 40' during power running and approximately 1300 ~ during regeneration] 40■
Therefore, it is possible to determine whether regeneration is being used or not, in the same way as when electricity is supplied at a substation that is a power supply source.

Current detector (0'r) 7 is used to detect the neutral point current 5+'@
-7.7-2 for each neutral point current 11t! Install it in the energized path of s. To detect the phase difference between both installation points, a square wave conversion circuit,
Discrimination circuit 9 consisting of a phase comparator circuit (there are various types such as time measurement type, sampling type, etc., but any type can be used), etc.
is installed, and the detection outputs of the current detectors 7-J and 7-2 are inputted thereto together with the voltage signal.

Note that the current phase comparison operation or the transmission of the result may be stopped when the current is below a certain value, and the determination may be made only when the electric vehicle 6 enters a predetermined section.

As shown in FIGS. 1(a) and 2, a power conversion device 10 for regenerative power recovery is installed near the power regeneration area, and its input end is connected to the trolley wire 2. Connect to feeder line 3,
The output end is connected to a separate system 12 to which a load 72 that consumes electricity is connected and is close to the power regeneration area, and the connection with the separate system 12 is controlled by the output of the discrimination circuit 9. If this is done, economic-adjacent t-labor federation will take place. This method of consuming regenerated power is particularly effective when the power regeneration area is located at the apogee of the substation, such as in the Changtang tunnel. In addition, since a power factor correction function (reactive power compensation function) can be easily added to the power conversion device 10, it is possible to easily add a power factor correction function (reactive power compensation function). ! This makes it possible to relieve pressure drops and contributes to the stable operation of electric vehicles by stabilizing the voltage.

As described above, according to the method of the present invention, power regeneration operation in an AT-type power feeding system is detected by comparing the phases of the neutral point currents of two ATs installed in the power regeneration area. It is possible to accurately determine whether or not regenerative operation is in place in an area, and by installing a power converter for regenerative power recovery near the power regeneration area, which has traditionally been abandoned due to economical and reliability considerations, A new system configuration that supplies regenerated power to a separate system becomes possible. In addition, it has become possible to supply power for reactive power compensation to the residential power generation area from nearby, reducing voltage drops and greatly contributing to stable operation. play.

[Brief explanation of drawings]

Figures 1 (a) and (b) are circuit diagrams showing a part of the electric railway system using electric power, and the relationship between the AT neutral point current and the position of the electric car in the electric system. The figure shown,
FIG. 2 is a block circuit diagram showing an example of an embodiment of the method of the present invention. 1-1~z-s...AT, 2...trolley wire, 3.
...Feeding line, 4...Rail, 5...Power supply, 6...
Electric car, 1-1 and 1-2... Current detector, 9...
Discrimination circuit, 10...power converter, 1]...load,
ν...Separate power system.

Claims (1)

[Claims] (1) In an AT-powered power feeding system for an electric railway that has an area with a continuous downward slope for a certain distance or more and uses regenerative braking to slow down electric cars, the above-mentioned slope area or the slope area and its adjacent area Detection of power regeneration operation characterized by detecting the neutral point voltage waves of two autotransformers installed in the area and comparing their phases to determine whether or not power regeneration is being performed. Method.