JPS59119750A - Water cooled system thyristor converter - Google Patents

Abstract

PURPOSE:To prevent the decrease of cooling water when a pump stops and then prevent adverse influences on a device by a method wherein valves are respectively provided at the inlet and the outlet pipe for the cooling water of an SCR converter, which are then operated by pump stop signal. CONSTITUTION:The valve 20A of the inlet water distribution pipe 12A and the vavle 20B of the outlet water distribution pipe 12B are electromagnetic valves which open and close by an external signal. The power interruption of the pump 16, the decrease of revolutions, and the decrease of water pressure are detected, and the detected result is impressed on the valves as the external operation signal, thus immediately blocking them at the time of abnormality. therefore, the upper cooling water in the SCR valve does not decrease, and the decrease of the reliability of an SCR converter by the crush of the water distribution pipes of an insulator due to vacuum, or by the liability to discharge does not occur.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a thyristor converter for AC/DC conversion such as DC power transmission or inter-frequency interconnection, and more particularly to an ice-cooled thyristor converter that is cooled by circulating a liquid.

[Technical background of the invention and its problems]

In recent years, advances in semiconductor devices have been remarkable, and highly reliable high-voltage, large-current thyristor elements have been developed, and the capacity of thyristor converters using these thyristor elements is increasing year by year. Therefore, in particular, as the Tenryu style has become more popular, how to efficiently cool the parts of the equipment has become a problem.

Conventionally, insulating oil, air, etc. have been used as the cooling medium for thyristor converters. However, the cooling performance of the above-mentioned cooling medium is limited. Therefore, many water-cooled thyristor converters have been developed that are air-insulated and cooled by water, which is easy to maintain and inspect, and has a high cooling effect.

Generally, a thyristor converter constitutes a three-phase bridge circuit as shown in FIG. i.e. IU, IV, IW, 2
U, 2V, 2W are thyristor pulp and AC terminals U, V,
An AC system 1 is connected to W, and 2 and 3 are DC terminals. Furthermore, with the recent increase in voltage and the reduction in the number of exchange stations, the second
As shown in the figure, add valve 3U to the circuit shown in Figure 1.

3V,! A three-phase bridge circuit consisting of W, 4U, 4V, and 4W is connected in cascade.

Part 3 about the conventional water-cooled thyristor converter when the thyristor converter connected as shown in Figure 2 is cooled with water.
This will be explained with reference to FIGS. 5 to 5.

FIG. 3 shows the thyristor pulp IU 28. It shows a four-tier stacked thyristor converter and its cooling system, which has an integrated structure by stacking 3U and then 4U on top of it.

I will clarify. ) is a thyristor module 8 that houses several thyristor elements 4 (six in series in the figure) and their attached circuits, such as an anode reactor 5, a voltage dividing resistor 6, and a capacitor 7, as shown in FIG. 9 are stacked in multiple stages.

The components that make up the thyristor module 8 and require cooling with water are the thyristor element 4, the anode reactor 5, and the voltage dividing resistor 6, which have large power losses.

When cooling such thyristor pulp with water, the third
As shown in the figure, a main water pipe 10 made of an insulating material is connected to both ends of the thyristor module 8 by means of water pipes 11k and JIB for thyristor module, respectively. Further, at ground level, an inlet water pipe 12A and an outlet water pipe 12B are connected to the main water pipes 1θA and 70B, and a storage tank 13, a heat exchanger 14, an ion exchanger 15, and a pump 16 are connected to each of them.

Cooling water is passed through the inlet water pipe 12A by the pump 16,
The water is sent to the main water pipe 10A, distributed to each thyristor module 8 by the water pipe 11A as shown by the arrow 17, cools each component, and is heated by heat loss.
The water is stored in the storage tank 13 from the main water pipe 10B through the outlet water pipe 12Bf. A cooling system is employed in which the water is cooled again from the storage tank 13 by the heat exchanger 14, purified by removing ions and impurities by the ion exchanger 15, and sent again to the thyristor converter by the pump 16. Therefore, when the cooling system shown in FIG. 3 is plotted, it becomes a cooling system diagram as shown in FIG.

In Fig. 3, 18 is a frame made of thyristor pulp, and 19 is a frame made of thyristor pulp.
is an insulator that insulates and supports the entire four-stage thyristor valve. Normally, when the voltage of one stage of such thyristor pulp is 125KV class, the distance between them is about 3m, and the third stage is about 3m.
As shown in the figure, when the thyristor pulp is stacked in four layers, its straw weight is approximately 1211. Furthermore, if a single unit is 250KV class and stacked in four tiers, the length of the straw will be approximately 20m.

In this way, in the tower-structured thyristor pulp, 1
When cooling by raising cooling water to a height of 0 m or more, when maintenance or inspection is required, or when the pump stops for some reason, the water in the pipes such as the thyristor module 8 located above 10 m will be affected by atmospheric pressure. For example, 1
In the case of atmospheric pressure, it drops to 10.337K, and the inside of the pipe where the water has fallen naturally becomes a vacuum.

Therefore, the piping used for thyristor pulp requires insulation, so insulating piping is almost never used, and as mentioned above, when a vacuum is created, insulated piping can be crushed and destroyed.
Furthermore, the vacuum condition makes it easier for discharge to occur, causing problems such as dielectric breakdown and reduced reliability of the thyristor converter.

[Object of the present invention]

An object of the present invention is to eliminate the above-mentioned drawbacks and provide a highly reliable water-cooled thyristor converter without any adverse effect on the thyristor converter.

[Summary of the invention]

In order to achieve this objective, the present invention provides an inlet water pipe 12A and an outlet water pipe 12B so that the cooling water at the upper part of the cylindrical valve does not drop when the pump stops.
The pump is characterized in that each pump is provided with a valve, which can be operated by a pump stop signal.

[Embodiments of the invention]

Hereinafter, the present invention will be explained with reference to FIG. 6, in which the same parts as in FIG. 5 are denoted by the same symbols.

In FIG. 6, a valve 20 provided in the inlet water pipe 12k
The valve 20B provided at the outlet water pipe 12B is, for example, a solenoid valve whose opening and closing are controlled by an external signal.

The valve 20B is opened when the pump 16 is operating normally, and when the pump 16 becomes abnormal or has stopped, this is detected and the valve 20A is opened.

Valve 20 by applying it as an external operation signal to 20B.
Then, 20B is closed. Here, as a signal for detecting that the pump 16 has become abnormal, a signal detecting a power outage of the driving power source of the pump 16, a decrease in the number of revolutions of the pump, or a decrease in water pressure of the pump 16 may be used. I can do it. With this configuration, when the pump 16 becomes abnormal or stops, the valves 201 and 20 are immediately closed.
B will be closed, so the cooling water in the thyristor valve will not drop.

FIG. 7 is a system diagram showing another embodiment of the present invention.
1 is a check valve, which prevents cooling water from going down from the valve without preventing the cooling water from going up to the valve side. Therefore, in this case, by using a solenoid valve or an electric valve as the valve 20B, it is possible to prevent the cooling water from dropping when the pump 16 is abnormal.

As described above, in the present invention, when the pump 16 is stopped or abnormal, the cooling water on the valve side can be prevented from dropping due to the actions of the valves 201, 20B and 20B.

〔Effect of the invention〕

As explained above, the present invention prevents the cooling water on the thyristor valve side from dropping even if the pump stops or malfunctions in a water-cooled thyristor converter, so the inside of the piping does not become vacuum. Therefore, it is possible to provide a highly reliable water-cooled SIRISK converter without causing damage to piping or insulation damage due to electrical discharge.

[Brief explanation of the drawing]

Figures 1 and 2 are block diagrams of a thyristor converter, Figure 3 is a block diagram of a cooling system for thyristor pulp that constitutes a conventional thyristor converter, and Figure 4 is a circuit diagram inside a thyristor module that constitutes a thyristor pulp. 5 is a cooling system diagram of FIG. 3, FIG. 6 is a cooling system diagram showing one embodiment of the present invention, and FIG. 7 is a cooling system diagram showing another embodiment of the present invention. 1... AC system, IU~4W... Thyristor converter, 2, 3... DC terminal, U, V, W... AC terminal,
4... Thyristor element, 5... Anode reactor, 6... Voltage dividing resistor, 7... Capacitor, 8... Thyristor module, 9-... Insulator, 10, IOB.
...Main water pipe, 11, JIB... Water pipe, J,? A
...Inlet water pipe, 12B...Outlet water pipe, 13...
・Storage tank, 14... Heat exchanger, 15...
Ion exchanger, 16...pump, 17...arrow, 1
8... Frame, 19... Insulator, 201.20B.
・1 valve, 21... check valve, 22... signal, 23...
・Electric valve. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 615 Figure 6 Figure 7 Commissioner of the Patent Office Kazuo Wakasugi 1 Case Indication Patent Application 1983-232919 No. 2 Name of the invention Water-cooled thyristor converter 3, Relationship with the case of the person making the amendment Patent applicant (30?) Tokyo Shibaura Electric Co., Ltd. 4 Representative (i, Amendment 7.) Elephant fake 3 figure

Claims (1)

[Claims] (1) Water cooling in which cooling water is circulated through inlet piping and outlet piping provided at the bottom of the thyristor valve to cool the heat-generating parts such as the thyristor elements of the thyristor valve that make up the thyristor converter. In the type thyristor converter, a valve is provided in each of the inlet pipe and the outlet pipe, and the valve is a valve that closes when the pump for circulating the cooling water stops or when an abnormality occurs. A water-cooled thyristor converter. c2) Heat-generating components such as the thyristor element of the thyristor valve constituting the thyristor converter are cooled by circulating cooling water through an inlet pipe and an outlet pipe provided at the bottom of the thyristor valve. The water-cooled thyristor converter is characterized in that the inlet pipe is provided with a check valve, and the outlet pipe is provided with a valve that closes when the pump for circulating the cooling water stops or there is an abnormality. Water-cooled thyristor converter.