PL178121B1 - Method of and system for providing interruption-free supply of power needed for a power alone - Google Patents

Abstract

The power supply system for internal consumption is designed especially for a high-output power plant. It consists of the sections of internal consumption switching stations for several power units, a direct current bus bar and the sections of general internal consumption. Unique characteristics: Transformer-rectifier sets (TP-P) are connected, through the switches (W1), to each block transformer (TB-1, TB-2,...TB-n, TB-i) of the section of internal consumption switching stations for several power units (A, B). The rectifiers (P) in the sets are connected through the disconnecting switches (O) to the direct current bus bar (S). The latter is connected through the switches (W2) to the thyristor current inverters (F). The latter are connected, through the three-phase double-coil transformers (TO) and switches (W3), to selected general internal consumption switching stations (PO).

Description

The subject of the invention is a system for supplying power plant auxiliaries, especially high power.

A system is known for supplying power plant auxiliaries which comprises a three-winding tap transformer connected to the power output path between the generator and the block transformer. In this system, the backup sources are transformers connected to the main switching station of the power plant and supplying the backup switching stations, from which in turn are supplied the switching stations for general needs of the power plant. The backup switching stations also supply the bus bridge, from which, in a branched system, backup supply connections to individual sections of the block switching stations are made.

The known system does not ensure the appropriate degree of reliability of the supply of selected general auxiliary devices, the operation of which is necessary, assuming that the power plant is kept ready for operation in the state of total failure of the power system.

The essence of the system according to the invention consists in the fact that to each block transformer of the switchgear section of several power units, transformer-rectifier units are connected via circuit-breakers, connected by rectifiers through disconnectors with a DC busbar, which is connected via circuit-breakers with thyristor inverters, which are connected by three-phase, two-winding transformers and circuit-breakers to selected general auxiliary switchboards.

The system according to the invention does not have the disadvantages of the known system and is characterized by the efficiency which ensures the continuity of power supply to the power plant in emergency cases, e.g. in the event of a total failure of the power system.

The subject of the invention is presented in more detail in the drawing showing the diagram of the system in the exemplary embodiment.

Each block transformer TB-1, TB-2, ..., TB-n, TB-and auxiliary switchboard of several power units A, B are connected via W1, three-phase, two-winding transformers TP supplying rectifiers P Power of TP transformers and rectifiers P is selected so that at least two TP-P units ensure proper operation of selected receivers of general own needs, in the initial stage of total failure of the power system.

Rectifiers P through O disconnectors continuously supply the DC bus bridge S, to which the F inverters are connected via circuit breakers W2, supplying three-phase two-winding transformers TO, connected via W3 to selected sections of the PO general purpose switchgear.

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The PO section is equipped with dummy devices, the operation of which is necessary to maintain the basic equipment of selected power units in operation for the purpose of further restitution of the power plant, after removing the system failure.

The transformers TP and TO are preferably equipped with voltage regulators under load, and their leakage reactances are chosen such that they correspond to the short-circuit power of the DC bridge S.

Transformer ratio should result from voltage parameters of rectifiers P and inverters F.

F inverters have voltage smoothing filters installed on the inputs and are equipped with output voltage frequency control systems.

The switching on of the relevant TP-P transformer-rectifier unit takes place in the following sequence: closing of the disconnector O, and then the switch W1, and the switching offs take place in the reverse order.

After connecting the power to the S bridge, W2 switches are turned off, F inverters are turned off, and then W3 switches connected to the PO switching station.

Scheduled shutdown of these teams takes place in the reverse order.

The power of TP transformers and P rectifiers is selected so that at least two TP-P units ensure the correct operation of selected general-purpose receivers in the initial stage of a total failure of the power system.

The voltage regulators of TP transformers are used to determine the loads of section B of block switchgears, and the voltage regulators of TO transformers determine the voltage values on the busbars of the PO switchgear.

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Publishing Department of the UP RP. Circulation of 70 copies. Price PLN 2.00.

Claims (1)

Patent claim A system for supplying auxiliary needs of a power plant, especially high power, containing sections of auxiliary switchgear of several power units, a DC bus bridge and sections of own general needs, characterized in that for each block transformer (TB-1, TB-2, ... TB-n, TB-i) of auxiliary switchgear sections of several power units (A, B) are connected through circuit breakers (W 1) transformer-rectifier units (TP-P) connected with rectifiers (P) through disconnectors (O) with the current busbar constant (S), which is connected via circuit breakers (W2) with thyristor inverters (F), which are connected via three-phase, two-winding transformers (TO) and circuit breakers (W3) to selected general-purpose switching stations (PO).