WO2025080240A1

WO2025080240A1 - Rotating rectifier unit block

Info

Publication number: WO2025080240A1
Application number: PCT/UA2024/000043
Authority: WO
Inventors: Denys Fedorovych STEPURA
Original assignee: Individual
Current assignee: Individual
Priority date: 2023-10-09
Filing date: 2024-08-12
Publication date: 2025-04-17
Anticipated expiration: 2026-04-09

Abstract

The invention relates to a field of energy sector, in particular, to a rotating block in the BVD-4000-3000 UZ exciter system, which can be used in energy facilities such as nuclear power plants. A rectifier block consists of two rings (6) with eighteen sections installed. Each section comprises a radiator (7), two diode blocks (8), two insulation blocks (9) and two fuses (10). The diode blocks (8) and fuses (10) are made of ceramic and aluminum.

Description

ROTATING RECTIFIER UNIT BLOCK

The invention pertains to the energy sector, specifically to the design of a rotating rectifier unit block within an exciter system of the BVD-4000-3000UZ (BBfl-4000-3000 Y3) type. These systems are utilized in energy facilities, particularly at nuclear power plants.

TECHNICAL BACKGROUND

The BVD-4000-3000UZ exciter is a complex device comprising two synchronous AC generators of the VGT-2100-150 (BTT-2100-150) type, containing rotating rectifiers of direct and reverse polarity. Each of these synchronous generators includes two ventilation rings with a rotating rectifier block.

The purpose of the rotating rectifier block is to convert the AC from the VGT-2100-150 generator into DC and transmit it to the rotor winding of the TVV-1000-2UZ (TBB-1000-2Y3) and TVV-1200-2UZ (TBB-1200-2Y3) turbo generators. The rotating rectifier unit (block) is assembled according to a three-phase bridge circuit (see Fig. 1).

A known rotating rectifier block features a modular design consisting of two ventilated rings mounted on the generator's armature, isolated from the shaft and each other, containing thirty-six sections each. Each section comprises a radiator to which two direct polarity diode blocks (cathode blocks) and two reverse polarity diode blocks (anode blocks) are attached, along with fuses. Each diode block is covered with a protective plate. The fuses are mounted on plastic blocks and interconnected with copper jumpers. A current conductor, with one end screwed into blind threaded holes in the ventilated rings and the other end connected to the semi-coupling area, ensures the supply of DC (via the rectifier’s direct and reverse polarity diode blocks) to the rotor of the TW-1000-2UZ and TVV-1200-2UZ turbo generators. The rectifier diode block converts the AC from the VGT-2100-150 synchronous generator into DC and transmits it to the turbo generator's rotor winding.

This known design, however, has significant drawbacks. The diode blocks and fuses are made of steel, resulting in each section of the rotating rectifier block weighing 9,4 kg. Given the operational rotational speed of 3000 rpm, there is a substantial risk of destroying the entire BVD- 4000-3000 UZ exciter system due to the centrifugal force exerted on the ventilated ring, which reaches 40,7 tons.

Thus, there is a technical problem in providing a rotating rectifier block design that is simpler and lighter, reducing the centrifugal force from each section and consequently increasing the overall safety of the BVD-4000-3000 UZ exciter system.

SUMMARY OF THE INVENTION

This technical problem is addressed by a rotating rectifier block comprising two ventilated rings 6, mounted on the generator's armature, isolated from the shaft and each other, containing sections. Each section includes:

• A radiator 7, mounted inside the ventilated ring 6 with two screws;

• Two direct and reverse polarity diode blocks 8 mounted on the radiator 7, each covered with a protective plate 12 and insulation 17;

• Two blocks 9, mounted on the radiator 7;

• Two fuses 10 mounted on the plastic (insulation) blocks 9 and interconnected with a copper jumper 11 using screws 14; distinguished by the fact that each of the specified ventilated rings contains eighteen sections; moreover, the direct and reverse polarity diode blocks 8 and fuses 10 are made of ceramic and aluminum.

The technical result of the device according to the invention is the simplification of the rotating rectifier block design by reducing the number of sections installed on one ventilated ring. Consequently, due to this and the use of materials with lower density for the diode blocks and fuses, the mass of each section of the device is significantly reduced, which in turn greatly decreases the centrifugal force exerted by it and enhances the overall safety of the BVD-4000-3000 UZ exciter system.

DETAILED DESCRIPTION THE INVENTION

As mentioned above, the invention relates to a rotating rectifier block consisting of two ventilated rings 6 mounted on the armature of a synchronous generator, isolated from the shaft and from each other, inside which sections are installed, each containing:

• A radiator 7, mounted inside the ventilated ring 6 with two screws;

• Two blocks 9, mounted on the radiator 7;

• Two fuses 10 mounted on the plastic (insulation) blocks 9 and interconnected with a copper jumper 11 using screws 14, distinguished by the fact that each of the specified ventilated rings contains eighteen sections; moreover, the direct and reverse polarity diode blocks 8 and fuses 10 are made of ceramic and aluminum.

Short description figures

The following figures the structure of the rotating leveler block is disclosed in more detail, by an invention

Figure 1 illustrates general scheme leveling current by help block equalizer, which rotates, where:

1 - diode bloc direct polarity (cathod block);

2 - reverse polarity diode block (anode block);

3 - block rectifier;

4 - bloc filter

Figure 2a illustrates electric scheme diode block direct polarity (cathodeblock).

Figure 2b illustrates electric scheme diode inverted block polarity (anodicblock).

Figure 3 illustrates construction rectifier block, what rotates according to the invention from the inside, where:

6 - ventilation ring;

7 - radiators;

8 - diod blocks;

9 - insulation blocks; 10 - fuses

Figure 4 illustrates separate section block equalizer, what rotates in axonometry, where:

7 - radiator;

10 fuses;

11 - copper jumper;

12 - protective plate;

13 screw.

Figure 5a illustrates the front view of a separate section of the rotating rectifier block.

Figure 5b illustrates the view of a separate section of the rotating rectifier block in a crosssection along line A - A, where

7 - radiators;

8 - diode blocks;

9 - insulation blocks;

10 - fuses;

12 - protective plate; 14 - screw;

15 screw;

16 copper contact;

17 insulating cover.

As previously mentioned, the BVD-4000-3000UZ exciter is a complex device consisting of two synchronous AC generators of the VGT-2100-150 type, which contain rotating rectifiers of the NE- X23M-4580-UXL4 type with direct and reverse polarity. The main nominal data of the exciter and its components (two synchronous generators) are provided in Table 1.

Table 1

Rectification, i.e., the conversion of alternating current to direct current in the rotating rectifier block according to the invention, occurs in the same manner as in the prototype — using a three-phase bridge circuit (see Figure 1) with diodes, which are electronic devices with two electrodes that allow current to flow in only one direction. A current conductor is placed along the axis of the generator shaft, with one end screwed into blind threaded holes in the ventilation rings and the other end connected to the semi-coupling area, ensuring the supply of direct current (due to the direct and reverse polarity diode blocks of the rectifier) to the rotor of the TVV-1000-2UZ and TVV-1200-2UZ turbo generators. The direct polarity diode blocks are located on one ventilation ring, while the reverse polarity diode blocks are on the other. Their schematics are illustrated in Figure 2. The rectifier diode blocks according to the invention operate alternately, each for one-third of the period. The load current equals the sum of the currents of each diode and always flows in the . same direction — from the synchronous generator to the turbo generator rotor winding.

Figure 3 shows the internal construction of the rectifier block according to the invention, and Figures 4 and 5 depict a separate section of it. Compared to the modular construction of the prototype, each ventilation ring 6 in the rectifier block according to the invention contains 18 sections. This design solution, combined with the fact that the diode blocks 8 and fuses 10 in each section are mounted on the radiator 7 in a crosswise manner (see Figure 4), allows for a significant reduction in the number of fastening parts. The radiators 7 serve to dissipate heat from the diode blocks. The fuses 10 provide protection against electrical overload.

Diode Parameters:

• Nominal current: 630 A;

• Nominal reverse voltage: 2000-2800 V.

Fuse Parameters:

• Nominal current: 500 A;

• Nominal voltage: 1000 V.

The materials chosen for the fuses 10 and diode blocks 8 in the rectifier block according to the invention are low-density materials, specifically ceramic and aluminum. More specifically, the diode blocks 8 are made of aluminum, and the fuses 10 are made of ceramic and aluminum.

The density of materials for the fuses and diode blocks in the prototype and the rectifier block according to the invention is shown in Table 2 (sources: Happy House and UM). Table 2

As mentioned above, the density of the materials for the diode blocks 8 and fuses 10 in the rectifier block according to the invention is at least 3-11 times lower than that of steel. Due to this, as well as the installation of fewer sections in each ventilation ring 6 in the rectifier block according to the invention, it has been possible to achieve a significant reduction in the overall mass compared to the prototype. This also leads to a proportional reduction in the centrifugal force acting on the outer surface of the ventilation ring 6, which consequently results in a substantial reduction in the risk of exciter failure due to the decreased load on the ventilated ring from the centrifugal force at a rotational speed of 3000 rpm.

Centrifugal force is typically calculated using the following formula (1):

F = m*V ²/r , (1) where:

F is the centrifugal force; m is the mass of the moving object;

V is the velocity of the moving object; r is the distance from the object to the center of rotation.

Therefore, with a section weight of 9.4 kg in the rectifier block at a rotational speed of 3000 rpm and a ventilated ring radius of 440 mm, the centrifugal force acting on it from one section will be 40.7 tons. In contrast, the weight of one section of the rectifier block according to the invention is 5.7 kg, and thus at a rotational speed of 3000 rpm and a ventilated ring radius of 440 mm, the force acting on it from one section will be 24.7 tons. Consequently, this leads to a significant reduction in the risk of failure of the entire BVD-4000-3000UZ exciter system and greatly increases the safety of its operation. This is critically important for energy facilities, particularly nuclear power plants.

Therefore, the application of the rectifier block according to the invention achieves the desired technical result, namely: reducing the mass of each section by more than 1.5 times (from 9.4 kg to 5.7 kg), thereby also reducing the centrifugal force by more than 1.5 times and enhancing the overall safety of the BVD- 4000-3000 UZ exciter system.

Claims

INVENTION FORMULA

1. As mentioned above, the invention relates to a rotating rectifier block consisting of two ventilated rings 6 mounted on the armature of a synchronous generator, isolated from the shaft and from each other, inside which sections are installed, each containing:

• A radiator, mounted inside the ventilated ring with two screws;

• Two direct and reverse polarity diode blocks mounted on the radiator each covered with a protective plate and insulation;

• Two blocks mounted on the radiator;

• Two fuses mounted on the plastic (insulation) blocks and interconnected with a copper jumper using screws; distinguished by the fact that each of the specified ventilated rings contains eighteen sections; moreover, the direct and reverse polarity diode blocks and fuses are made of ceramic and aluminum.