Reconstruction of the 110/10 kV substation electrical part of the Mozyr electric networks due to equipment wear

Contents

Introduction

1 Characteristic of electrical system of 110/10 kV "Traction" substation

1.1 Main electrical connection diagram of substation

1.2 Main electrical equipment of substation

1.2.1 Power and auxiliary transformers

1.2.2 Main switching equipment

1.2.3 Measuring equipment, electrical energy metering devices

1.2.4 Equipment protection against atmospheric and switching overvoltage

1.2.5 Means of capacitive current compensation

1.3 Assessment of substation electrical equipment status

2 Selection of optimal power of transformers at 110/10 kV "Traction" substation

2.1 Investigation of operation modes of power transformers

2.2 Selection of power transformers at "Traction" substation

3. Calculation of short-circuit currents of 110/10 kV electric substation "Traction"

3.1 Procedure for calculation of short-circuit currents

3.2 Preparation of substitution scheme and determination of its parameters

3.3 Results of short circuit current calculation

4 Measures for replacement of substation electrical equipment

110/10 kV "Traction"

4.1 Selection of switchgear schematic diagram

110 and 10 kV

4.2 Selection of power equipment on the 110 kV side

4.2.1 Selection of switching equipment

4.2.2 Selection of overvoltage limiters

4.3 Selection of power equipment on the 10 kV side

4.3.1 Selection of switching equipment

4.3.2 Selection of instrumentation

4.3.3 Selection of current and voltage transformers

4.3.4 Transformer selection and substation auxiliary diagram

4.3.5 Selection of overvoltage limiters

4.3.6 Selection of earthing arc-quenching reactors

5 Relay protection and automation of substation elements

5.1 General provisions

5.2 10 kV Outgoing Line Protection

5.3 Transformer relay protection

6 Electrical lighting of substation

6.1 Calculation of OPC lighting network

6.2 Calculation of RP lighting network

7. Organizational and economic part of the project

7.1 Determination of estimated cost of substation reconstruction

7.2 Economic justification of equipment replacement measures at substation

7.3 Technical and economic indicators of the project

8 Health, Safety and Environment

8.1 Structure of organization of labor protection at the enterprise of electric networks

8.2 Peculiarities of health and safety organization at substation

8.3 Ecology and Environmental Protection

Conclusion

Literature

Applications

Introduction

The development of the economy is inextricably linked with the electrification of all sectors of the national economy. The vast amount of electricity generated by generators of various types of power plants is transferred to consumers, which are industry, agriculture, construction, transport and urban utilities.

The transmission of electricity from sources to consumers is carried out by energy systems combining several power plants. Power supply systems

Continue to be the main source of electricity for consumers, including the most energy-intensive, industrial enterprises.

Implementation of reliability, quality and economy requirements ensures reduction of costs during construction and operation of all components of the power supply system, implementation of electrification plans of all branches of the national economy with high technical and economic indicators, reliable and high-quality power supply of industrial enterprises. As a result, the electric armament of labor increases, and this in turn ensures an increase in labor productivity and the degree of its mechanization .

The purpose of this diploma project is to reconstruct the Traction electric substation of the Mozyr electric networks in connection with wear and tear. This is necessary to ensure normal power supply to the substation consumers, increase the reliability of power supply, economical transmission of electricity to consumers, provision of redundancy and protection of electrical network elements. The initial information for the execution of the diploma project is collected in pre-diploma practice.

The diploma project proposes technical solutions and recommendations for the reconstruction of the Tyagovaya substation. Proposals have been developed to improve the switchgear layout and replace electrical equipment. At the Tyagovaya substation, power transformers, switching devices, auxiliary transformers, relay protection and automation equipment for modern equipment were selected, as well as arc-extinguishing grounding reactors were installed. To select the electrical equipment of the substation, short-circuit currents were calculated using the TKZ3000 software system. The calculation of relay protection settings was made using the Microsoft Office software package. External and internal lighting of the substation was calculated. The diploma project addresses safety and health issues. The proposed technical solutions for the reconstruction of the substation also have economic justification.

The calculations given in the design and the graphic part are based on the current normative and reference information and literature. Calculations were made taking into account the main requirements - "Rules for the installation of electrical installations." The design diagram of the substation meets all the requirements of reliability of equipment operation.

1 characteristic of the electric farm

110/10 kV "TRACTION" SUBSTATIONS

The assessment of the electric farm will show the need to reconstruct the 110/10 kV Traction substation. This section covers a number of issues, the solution of which will allow to identify the required scope of work to improve the technical condition of the existing substation. Special attention should be paid to:

1) electrical connection diagrams - their reliability, simplicity and ease of operation;

2) electrical equipment of the substation - physical wear;

3) the possibility of introducing new technologies - telemechanics systems, automated systems for accounting for electric consumption, relay protection and automation based on microprocessor technology.

1.1 Main electrical connection diagram of substation

Electric substation 110/10 kV "Traction" is an electrical installation for receiving, converting and distributing electric energy. The substation includes distributing devices (ORU110kV, RU-10 of kV), two transformers (TDN10000/110/10), the control unit and other auxiliary devices. The substation is powered by two overhead lines: VL110 Mozyr330 - Solzavod No. 1 and VL110 Mozyr330 - Solzavod No. 2.

Figure 1.1 shows a simplified schematic diagram of the 110/10 kV Traction electrical substation. An open 110 kV switchgear uses a bridge circuit with two sectional meters in the bridge and separators in the transformer circuits. Section disconnectors QS3 and QS4 are normally disconnected.

On the low side of 10 kV, a circuit with one partitioned bus system is used. In normal operation, section switch Q3 is OFF. In case of emergency disconnection of power transformer or supply line, section switch Q3 is switched on automatically by ALT.

Sheet 1 of the graphic part of the diploma project shows the main diagram of electrical connections of the current 110/10 kV traction substation.

The Tyagovaya substation is designed for power supply to the tram department of MNPZ OJSC, the Krinichnaya experimental base, the children's hospital and the city.

Tram control belongs to consumers of category I. Interruption of the power supply of this consumer can lead to a violation of the technological process, which will entail heavy material damage. To ensure uninterrupted power supply to consumers of category I, they must be supplied from two transformer substations. Then power supply interruption will occur during automatic power supply recovery, which is permissible for PUE [1].

The children's hospital also belongs to consumers of category I, since a break in its power supply can lead to a danger to people's lives.

The Krinichnaya experimental base, which belongs to consumers of category II reliability, is fed from the Tyagovaya substation. This consumer must also be powered by two transformer substations.

Thus, the electrical diagram of the substation meets the reliability requirements for it, as it provides reliable power supply to consumers of categories I and II.

1.2 Main electrical equipment of substation

The Tyagovaya substation was designed using a complete transformer substation from factory units of the Kuibyshev Electric Shield Plant.

The substation equipment is arranged in accordance with the construction codes and regulations (SNiP) and the electrical installation regulations (PUE). The territory of the substation is protected from household buildings by mesh fencing.

The substation consists of the following distributing devices: ORU110 of kV and RU10 of kV.

ORU-110 kV is made of separate units, which are a structure with mounted equipment. All switchgear devices are located on low reinforced concrete bases. In the territory of the switchgear, passes are provided for the possibility of installing and repairing equipment.

Assembly buses in 110 kV OPC are made of flexible conductors (AC120 wire). The tires on the portals are attached using suspended insulators.

The foundation for transformers is made of NSP plates on a gravel cushion and FBS units. Under the transformer there is an oil receiver. Fencing of oil intake pit is made of PT 10.5 plates.

Cables of operational circuits, control circuits, relay protection and automation are laid in trays made of reinforced concrete structures without their deepening into soil or in metal trays suspended from the RMS structure.

RU-10 kV is equipped with cabinets of type KRU210. KRU210 consists of armoured type cabinets (divided into compartments) and bus bridges.

Structurally, the following compartments are indicated in the cabinets:

1) equipment of main circuits - compartment of the rolling-out element;

2) prefabricated tyres - compartment of prefabricated tyres;

3) line connection compartment;

4) relay protection and automation equipment - secondary switching compartment.

On the rolled-out element there is an oil switch of the VMPP series, arresters, current and voltage transformers, sectional disconnectors. The rolling out element in the cabinets has two fixed positions: working and control (test). Movement of the rolling out element from one position to another is carried out by means of a rolling out mechanism, at that the current-carrying parts are closed by protective shutters. Fixing devices provide fixing of rolling out element and prevent its spontaneous movement inside cabinet at operation of all mechanisms both in normal mode and in case of short circuit. Cabinets are made in such a way that personnel safety is ensured during their inspection and maintenance, including operations in the switch compartment and cable compartment (including connection and disconnection of power cables) in the presence of voltage on KRU prefabricated buses and without disruption of circuits in neighboring cabinets.

1.2.1 Power and auxiliary transformers

On electric substation of 110/10 kV "Traction" two power dvukhobmotochny transformers are installed: T1 and T2 of TDN10000/110/10 type. Neutrals of transformers windings in normal condition are separated to reduce short circuit currents. Table 1.1 shows the characteristics of T1 and T2 power transformers.

The power of auxiliary consumers of the substation is not large, so they are connected to the 380/220 V network through T3 and T4 step-down transformers of TM63/10/0.4 type. Auxiliary transformers are connected by strippers to the inputs of power transformers T1 and T2 and are protected by fuses of PKT10/30 type. Table 1.2 shows the characteristics of transformers T3 and T4.

1.2.4 Equipment protection against atmospheric and switching overvoltage

From lightning surges, as well as from the maximum possible internal surges, all electrical installations of the substation are protected by valve arresters: PBS110- in the circuits of power transformers T1 and T2; PBC35 + 15 - in neutrals of power transformers T1 and T2; RVO10 - on 10 kV prefabricated tires.

The substation is protected from direct lightning strikes by rod and cable lightning rods.

1.3 Assessment of substation electrical equipment status

The Tyagovaya substation was commissioned in 1979. Thus, power transformers and auxiliary transformers are in operation for 27 years, i.e. their service life has expired, so they are subject to replacement. The service life of switching equipment, measuring transformers has also expired. Construction structures, reinforced concrete structures located on the territory of the substation are in a condition suitable for further operation.

Conclusions on Chapter

This chapter describes the main electrical connection diagram of the substation, which is a bridge diagram with two sectional disconnectors in the jumper and separators in the transformer circuits. Currently, such a scheme does not provide enough reliable power to consumers. Therefore, during the reconstruction of the substation, a new scheme will be selected.

The electrical equipment of the substation has developed a depreciation life. Therefore, the following are subject to replacement: power transformer T1, auxiliary transformers; arresters - they will be replaced by overvoltage limiters (VSD). New switching and measuring equipment will be selected.

2 selection of optimal power of power transformers at 110/10 sq "traction" substation

As can be seen from the previous section, the service life of both the first transformer and the second transformer has expired, so they are subject to replacement. To select the optimal power of transformers, it is necessary to examine their operating modes and determine the maximum load of the electrical substation. Analysis of the obtained data will make it possible to draw a conclusion about the load of power transformers. If the load factor is not high (Kz≤0,5), it will be necessary to replace transformers with transformers of lower power. At the same time, it is necessary to take into account the stability of the operating modes of transformers and the prospects for increasing the load .

In order to obtain more accurate and visible results, load regimes over several years are subject to investigation.

Conclusion

In the diploma project, she studied the main scheme of electrical connections, got acquainted with the main electrical equipment of the substation, studied the operation modes of power transformers T1 and T2, determined their load factors. Calculation of short-circuit currents using TKZ3000 software system.

Power TDN10000/110/10 transformers developed the depreciation service life and have low load factors therefore we will replace them with TMH4000/110/10 transformers.

During the reconstruction of the Tyagovaya substation, a bridge scheme with switches at transformers was used. Two TM100/10/0.4 type transformers are installed for auxiliary power supply.

Also in the diploma project, VMPP10 oil switches were replaced with vacuum switches of type BB/TEL1012.5, gas-insulated switches of type LTB145D1 and connectors of type D123 were installed on the 110 kV side. On the 110 and 10 kV side, OPNU/TEL110/84UHL1, OPN-P/TEL-10/11,5UHL1 were installed instead of arresters. TPL10 current transformers were replaced with TPK10, NTM10 voltage transformers with NAMIT10U3. Grounding arc-quenching reactors of the RUOM480/11/U type were also installed on the 110 kV side.

In addition, the ORU lighting network was calculated using floodlights of the IO04100001 type with G10005 lamps. Internal lighting of the RDU is made with lighting fixtures of TCSO58/1361 type with luminescent lamps TLD40. To protect outgoing lines, we use MICOM P122 microprocessor devices, for differential protection of the MICOM P632 transformer. The remaining transformer protections are made on the input protection devices. On the high side, MICOM P124 was used, and on the low MICOM P122.

In the organizational and technical part of the project, an estimate was made for the reconstruction of the Tyagovaya substation. They also determined the main technical and economic indicators, from which it is clear that measures to replace equipment are economically feasible.

In the section, labor protection, safety equipment and ecology disclose the organization of labor protection in the Mozyr electric networks and at the substation