JPS6280134A - Transformation equipment for d.c. electric railroad - Google Patents

Abstract

PURPOSE:To improve the utilization efficiency of an equipment capacity, by a method wherein, in a transformer equipment for a d.c. electric railroad having power reproducing function, a rectifying device for forward conversion and an self-exciting type converting device for both forward and reverse conversion are provided, and a part of a load power is fed from the self-exciting type coverting device. CONSTITUTION:A series circuit of vacuum breakers 7 and transformers 2 and 4 are connected in parallel to an a.c. source system 1, and an a.c. power outgoing from the transformers 2 and 4 are fed to a rectifying device 3 and a self-exciting converting device 5. The a.c. power is converted into a d.c. power by the rectifying device 3, and the d.c. power is fed to a load 6 through a high speed breaker 8 and a disconnecting switch 9. The a.c. power is converted into a d.c. power by the converting device 5, and the d.c. power is fed to the load 6 through the high speed breaker 8, the disconnecting switch 9, and a d.c. reactor 10. Responding to the voltage on the output side of the rectifying device 3, a control signal is fed to the coverting device 5 by means of a control device 11, and control is made such that a ratio between a current ISR, occupied in a load current Il, from the rectifying device 3 and that from a converting device ICON is brought into a given state.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to conversion equipment for DC electric railways equipped with a power regeneration function through 1U power inversion, and particularly for large-scale railways that require high efficiency operation. The present invention relates to electrical equipment suitable for power substations.

[Background of the invention]

A self-excited converter (conversion device that can convert AC to DC and converts DC to AC for both forward and reverse purposes) is used as a substation for DC 1-air railways, so that regeneration control can be performed. However,
In conventional metamorphosis equipment like this, as shown in Figure 4,
The self-help conversion device 5 can be used alone to convert the load 6 from the
It was designed to supply lf flow power to the In addition,
In FIG. 4, 1 represents an AC power supply system, and 4 represents a transformer for the F2 system. During single power regeneration, the DC squid from the load 6 is reversely converted by the self-excited converter 5 and absorbed into the power supply system 1 via the transformer 4.

However, self-excited type switching devices have relatively low efficiency due to commutation losses, and especially during commutation losses, large 1411
The snubber loss is almost unrelated to the load and is related to the installed capacity, so the efficiency decreases significantly at low loads.This characteristic is a bottleneck for residential railways with high peak loads, and low harmonics, Although it has advantages such as power factor control, it has been difficult to apply it to large-capacity substation equipment in the past.

Therefore, in order to compensate for this point, for example,
As disclosed in Publication No. 70185, a system has been proposed in which a diode rectifier, t, is provided in parallel to a self-commutated conversion device, so that the self-excited conversion device handles only one regenerative power. .

However, in this method, 1
The power conversion ability can only be used for single-force regeneration suppression, and the equipment capacity is greater than necessary, resulting in a significant increase in cost.

[Purpose of the invention]

The purpose of the present invention is to eliminate the drawbacks of the above-mentioned prior art, provide a DC electric generator with a power regeneration function, which has a sufficiently high utilization rate of installed capacity, and which can be applied to large-capacity substations to achieve high efficiency. Provides substation equipment for railways.

[Summary of the invention]

In order to achieve this object, the present invention provides an odd type of equipment in which a rectifier for forward conversion is provided with a converter for forward/reverse use to have a power regeneration control function, in which load power is also supplied by the converter. It is characterized by the fact that it allows

[Embodiments of the invention]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the direct current (DC) power substation equipment for railways according to the present invention will be explained in detail with reference to the illustrated embodiments.

FIG. 1 shows an embodiment of the present invention, in which 2 is a transformer for a rectifier, 3 is a rectifier consisting of bridge-connected diodes, 7 is a vacuum circuit breaker, 8 is a high-speed circuit breaker, and 9 is a rectifier.
1 is a disconnector, 10 is a DC reactor, and 11 controllers, and the AC power supply system 1, converter transformer 4, self-excited converter 5, load 6, etc. are the same as in the conventional example shown in FIG. Note that as the self-excited converter 4, a PVl14 (pulse width f modulation) system using a GTO (gate turn thyristor) as a switching element is often used.

The arrangement+i device 3 converts (rectifies) the AC' power that can be supplied from the AC power supply system 1 through the vacuum circuit breaker 7 and the transformer 2 into DC power, and then converts (rectifies) the AC power that can be supplied from the AC power system 1 into DC power through the pan speed circuit breaker 8 and the disconnector 9. It serves to supply DC current Lp to the negative Ur (electric car) 6.

The converter 5 converts AC power supplied from the power supply system 1 via the vacuum A to R converter 7 and the transformer 4 into DC power, and converts the AC power into DC power via the high-speed circuit breaker 8 , the disconnector 9 , and the DC reactor 10 . The load was 6 and I was asleep. In addition to supplying ON, when the terminal voltage of the load 6 rises above a predetermined value, the DC power sent out from the load 6 is converted into AC power, which is then absorbed into the current TJg and the system 1. It functions to perform power regeneration control.

The control device 11 controls the output of the rectifier 3, i.e., the acid pressure and
A current I8R etc. is detected, and a control signal (PWM control signal) is supplied to the converting device 5 in accordance with this, and the load flowing to the load 6 is divided into the current I8R from the rectifying device 3 and the current I8R from the converting device 5, which occupy the current Il. Electrician. . It controls so that the ratio of H is in a predetermined state, and also performs the control necessary for the above-described power regeneration control.

Next, the operation of this embodiment will be explained with reference to FIGS. 2 and 3.

These figures show the details of the current sharing control of the rectifier 3 and the converter [5] by the control device 11. The horizontal axis is the load current I, 5, and the vertical axis is the current I8R and 1.
Each represents 0°Ml. Therefore, the current shown by the solid line (
Engineering. R:"IC!ON) becomes the current Ik. In addition, in the figure, the right side of the vertical axis is the state where the current factor l is supplied to the load 6, and the left side is the state where the current factor l is supplied from the load 6 in the opposite direction. In addition, the one-dot chain line indicates the current shared by the converter 5.ON, and the two-dot chain line indicates the current shared by the rectifier [3]. Represent each.

In these figures, first, Figure 2 shows the case when the current sharing ratio between the rectifier 3 and the converter 4 is controlled to be constant, and Figure 3 shows the case when the load power exceeds the rated capacity of the rectifier 3. This is a case where power is supplied from the converter 5 only when the load power does not reach the rated capacity of the rectifier 3, and the power supply from the converter 5 is stopped.

However, in any of these cases, since the rectifier bag f3 does not have power regeneration capability, the self-excited converter 5 shares all the current during power regeneration, as shown on the left side of these figures.

Next, the results of control for such an embodiment of the present invention will be explained.

In recent years, standard electric railway substations with electric power regeneration functions have forward conversion capacities of 2000 to 60 G OKW.

Consider a case where the present invention is applied to a 111,000 KW substation. In the embodiment shown in FIG. 1, the capacity of the rectifier 3 is 3000 kW, and the capacity of the converter 5 is 1000 kW.
Assume the case of KW.

Further, the efficiency of the rectifier IIt3 is 98.5%, and the efficiency of the converter 5 is 96%.

Then, in this example, the total efficiency is 97.6% and the loss is 95 KW at the maximum output of 4000 KW.

On the other hand, if this is assumed to be a system using only the converter shown in FIG. 4, the efficiency will be 95 inches and the loss will be 200 KW.

Therefore, according to this embodiment, highly efficient operation is possible, and moreover, the operation can be performed at the full capacity of the equipment, and the equipment can be used effectively.

In particular, according to the control method shown in Fig. 3, since the converter 5 does not operate in the low load region, it can be operated with the same efficiency as the rectifier 3 alone, making it possible to significantly improve efficiency at light loads. Become.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to operate substation equipment equipped with a self-excited converter for the bottom power regeneration function with high efficiency. It is possible to easily provide DC electric railway substation equipment that can always be operated at high efficiency with a small decrease in performance, and that can effectively utilize the equipment capacity.

[Brief explanation of drawings]

Fig. 1 is a system configuration diagram showing one embodiment of the present invention;
3 and 3 are explanatory diagrams each showing an example of a control mode in an embodiment of the present invention, and FIG. 4 is a block diagram showing a conventional example of substation equipment. 1... AC power supply system, 2... Transformer for rectifier, 3... Rectifier, 4... Transformer for converter, 5... ...Self-excited conversion device, 6.
...Load, 7...Vacuum circuit breaker, 8...
...High speed circuit breaker, 9...Disconnector, 10...
...DC reactor, 11...Control device. f゛Representative Patent Attorney Kenjibu Take (1 other person)・゛Shiran Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. A direct current electric railway substation equipment equipped with a power regeneration function, which includes a rectifier for forward conversion, a self-excited converter for both forward and reverse conversion, and the self-excited converter for the output power of the rectifier. 1. A direct current electric railway substation equipment, comprising: a control device for controlling the ratio of converted power of the exciter type converter, and configured such that at least a part of the load power is supplied from the self-exciter converter. 2. The DC electric railway substation equipment according to claim 1, wherein the ratio control by the control device is configured to be a constant ratio with respect to the load power. 3. In claim 1, the control of the ratio by the control device sets the conversion output of the self-commutated converter to zero until the load power reaches a predetermined value, and then reduces the rectification output when the load power reaches a predetermined value. A direct current electric railway substation equipment, characterized in that it is configured to perform control to maintain the output power of the device at this predetermined value.