JPS59136030A - Frequency converting power supply facility - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to frequency conversion equipment for electric θF equipment located in areas with different frequencies.

[Prior art]

Figure 1 is a circuit diagram of the prior art.

This shows a case in which power is supplied from an AC system (variable current feeder) 1 to an AC system (AC feeder) 5 with a different frequency. (For example, the Tokaido Shinkansen runs in the 608Z area and the 50Hz area, so the 50H2 A synchronous-synchronous frequency conversion facility is installed in the area to supply 60H2 to the overhead contact lines.

To adjust the power supply in response to changes in the load 6, the voltage of the AC feeder line 5 is detected by the ACPT7, and the voltage of the AC feeder line 5 is adjusted by the field current flowing through the field winding 9 of the synchronous generator 4 and AVVB2. This is done by keeping the voltage constant.

FIG. 2 is a diagram showing the load on a locomotive running on an AC feeder line.

S is the line side, 几 and T are two-phase AC obtained from Scott connection, and the AC load balance between 几-8 and T-8 is as follows.
If it is, the three-phase AC side of the primary side of the Scott connection can also be adjusted.

Therefore, it can be seen that load fluctuations occur every time the AC locomotive passes by. It is also known that the fluctuation has a peak.

FIG. 3 is a curve representing the load fluctuation of load 2.

The load on the slope (kW) is expressed qualitatively by taking time t(S)k on the horizontal axis.

As shown in curve 11, load fluctuations with a low frequency, ie, small fluctuations, can be sufficiently followed by the flywheel effect 3 and the control of the AVR 8 as a response of the rotating machine. This is shown by curve 16 in FIG. The vertical axis V indicates the voltage of the AC system 5.

However, when there is a sudden load peak as shown in Figure 3, and
If this continues for a certain period of time, the flywheel effect and AVR will not be able to follow it, resulting in a curve 17 as shown in FIG.

Such load fluctuations apply unreasonable force to the shafts and bearings of rotating machines, so the lifespan of frequency conversion equipment using rotating machines installed in AC power stations with large load fluctuations is longer than that of a general constant load supply. It is thought that the lifespan is significantly shorter than that of

Therefore, the system shown in FIG. 5 includes a forward converter 32, a DC reactor 31, and an inverse converter 33 in parallel to the frequency conversion equipment 2-4 and 7-9 using conventional rotary machines.

In Figure 5, bus 1 connected to the feeder line of the 50 H7 system
As shown in Figure 2, the voltage applied to the circuit changes each time a load passes through it, and since the load is not well-balanced in three phases, voltage fluctuations occur unbalancedly for each phase. It is possible that In other words, the entire three-phase unbalanced AC system is connected to the forward converter 32 of FIG. 5, which is not preferable. (Problems such as current pulsation in the DC circuit, DC excitation of the transformer due to variations in commutation time, and generation of harmonics) [Object of the Invention] The purpose of the present invention is to It is an object of the present invention to provide frequency conversion power supply equipment that can achieve good power flexibility even in sudden load fluctuations by connecting thyristor (static type) frequency conversion equipment.

[Summary of the invention]

The present invention uses two single-phase converters to cope with three-phase unbalance of AC side voltage in equipment in which a frequency converter using a rotating machine and a thyristor frequency converter are connected in parallel.
The main feature is that the units can be operated in parallel.

[Embodiments of the invention]

The configuration of the thyristor section of the Thyrisk converter shown in Fig. 6 is shown in Fig. 6.
As shown in the figure.

A single-phase AC circuit is configured as two circuits (66, 6
7) By providing and connecting the thyristor converters 68 and 69 for each circuit and connecting the outputs of 68 and 69 in parallel, the influence of three-phase unbalance can be prevented.

FIG. 7 is a vector diagram showing the phase relationship when Scott connection is applied. Two single-phase AC voltages are 90
It has a phase difference of °.

FIG. 8 is a diagram showing the waveform.

Edt and Edm are single-phase AC circuit 66.67 (7) voltage values. The voltages Ed t and Edm are inputted to a converter (in this case 8 is a forward converter) 68 and 69 to obtain a DC voltage Ed. In the figure, 2 is the electric motor, 3 is the flywheel, 10 is the load curve average value, 15 is the rated voltage, and 21 to 23
is a single-phase AC line, 24.25 is a train load, 26.27 is a pantograph, 34.35 is an AC side, 62 is a thyrisk element, and 63 is a DCL.

64.65 is the DC circuit, Ed is the converter, and 68.69 is the output voltage when connected in parallel.

〔Effect of the invention〕

According to the present invention, stable operation of a static (thyristor) converter can be continued regardless of three-phase AC unbalance. In other words,
Compared to the conventional three-phase Graetz connection, there are problems such as generation of pulsating voltage in the DC circuit due to voltage unbalance on the AC side, generation of harmonics, DC excitation of the transformer due to variations in commutation period, insufficient phase margin angle during inverter operation, etc. It is possible to prevent this.

[Brief explanation of the drawings] Figure 1 is a conventional system diagram, Figure 2 is an explanatory diagram of train load, Figure 3 is a diagram showing all load fluctuations, and Figure 4 is a conventional system diagram for load fluctuations. A diagram showing voltage fluctuations, FIG. 5 is a system diagram of an embodiment of the present invention, FIG. 6 is a detailed diagram of the present invention, and FIG. 7 is a voltage vector diagram of each part when performing Scott connection.
FIG. 8 is a DC voltage waveform diagram when converters (at the time of forward conversion) are connected in parallel. 61... Transformer, 62... Thyristor element, 63...
・・DCL, 64.65 ・DC circuit, 66.67・
...Single-phase AC circuit. Imo 2 closed figure 3 ■ 1 knight 4 prisoners ■

Claims (1)

[Claims] 1. In the electrical equipment of an AC locomotive that passes through areas with different frequencies, a frequency conversion equipment made of Cyrisk is installed in parallel with the equipment that distributes power to all rotating machines. Frequency conversion power supply equipment. 2. In the frequency conversion equipment according to claim 1,
Frequency conversion power supply equipment characterized in that a converter on the forward conversion side is configured to operate in parallel with two single-phase converters.