35/10 kV agricultural substation design

Contents

Contents

Introduction

1 General characteristics of the substation

1.1 Connection of substation to the system

2 Characteristics of outgoing lines

3 Substantiation of substation reconstruction

4 Selection of power transformers

4.1 Technical and economic calculation of transformers

5 Calculation of short-circuit currents

5.1 Design diagram of plants

5.2 Equivalent substitution schemes

5.3 Calculation of short-circuit currents

6. Selection of protective and switching equipment

6.1 Selection of switches and disconnectors

6.2 Selection of current transformers

6.3 Selection of voltage transformers

7 Cable and wire selection

8 Substation Auxiliary Calculation

9.Recalculation of relay protection

9.1 Calculation of relay protection of outgoing lines

9.2 Power transformer protection calculation

9.2.1 Calculation of differential protection of transformers

9.2.2 Maximum current protection

9.2.3 Overload Protection

9.2.4 Gas protection of transformers

9.3 Calculation of automation devices

9.3.1 Automatic switching on of reserve

9.4 Auxiliary transformer protection

10 Organizational and economic part

10.1 Technical - economic comparison of power supply circuit variants

10.2 Calculation of cost estimate for construction and installation works

10.2.1 Electrical Equipment Specification

10.2.2 Preparation of cost estimate for construction and installation works

10.2.3 Recalculation of estimates in 2006 prices

10.2.4 Preparation of cost estimate for dismantling works

10.2.5 Cost Estimate for Commissioning

10.3 Organization of construction and installation works for the commissioning of the power facility

10.3.1 Calculation of the number and composition of electrician crews

10.3.2 Ribbon Graphics Development

11. Occupational Safety Section

11.1 Introduction

11.2 Design of safety measures during substation reconstruction

11.3 Calculation of lightning protection devices

11.4 Increase of stability of facility power supply in conditions of possible emergency situations

List of literature

Applications

Introduction

Currently, in connection with the transition of agriculture to an industrial basis, the construction of large livestock complexes, an increase in electricity consumption in production and in everyday life, the unit capacity of electric consumers is growing. But the structure of the organization of agricultural production, the low density of the population of rural areas determine the low density of electric loads and the significant length of electric networks.

Power supply organizations constantly carry out technical measures to improve the reliability of equipment operation and reduce accidents in the directions: improving power supply schemes, reducing the length of 10 kV and 35 kV distribution network lines, building an HF to reserve substations.

The basis of the POS system is 0.38 110 kV electric networks, from which mainly agricultural consumers are supplied with electricity, including household utilities, land reclamation and water management facilities, as well as enterprises and organizations designed for household and cultural services to the rural population..

Transformer substations (TP) 35110 kV, used for power supply of agricultural areas, have one or two transformers with a voltage of 35/10 kV, with a capacity of 6306300 kV▪A; 110/10 kV - 250010000 kV▪A; 110/35/10 kV - 630080000 kV▪A. The location of the substation is selected near the center of electrical loads, roads and railway stations. The substation (MS) shall be located, as a rule, on land unsuitable for agricultural use; in an undisturbed or shrub-occupied area; if possible outside zones of intense natural and industrial pollution. An important requirement when placing an MS is to provide convenient VL calls.

Rational design of network IR of all types and categories and, in particular, rational and economical construction of main electrical circuits, selection of equipment and equipment parameters, as well as their optimal arrangement is a complex and responsible task.

The theme of the diploma project is the design of a 35/10 kV agricultural substation. The construction of the substation is necessary for power supply to the village of Lomovatka and consumers of the Velikoustyug district. The construction will make it possible to bring the highest voltage of 35 kV to the center of electricity consumption, which gives 10 kV distribution networks redundancy and minimum length of lines.

Substantiation of substation electrical equipment reconstruction

The 35/10 kV Lomovatka substation was built in 1958. It belongs to the Velikoustyug electric networks, OJSC Vologdaenergo. Currently, the substation is in a very worn out state. The substation building is in dilapidated condition. The fence is destroyed and does not comply with the norms and rules. Substation lighting is in poor condition. All lamps do not comply with fire safety standards. There is no alarm or protection at the substation. All operations related to operational switches are performed only manually. The wear of all equipment is about 83%. The transformer at the substation is installed with a capacity of 1600 kVA, which is not enough due to the expansion of production (lower warehouse). Auxiliary transformer is installed with insufficient power (25 kVA).

In order to eliminate these disadvantages and reconstruction of this substation is carried out: the 35/10 kV transformer is replaced with a more powerful one, TSN is replaced, relay protection is installed to ensure reliable operation of the substation. In cases of emergency disconnection of the designed substation, 10 kV tyres from the VL10 kV railway are protected. This line in the normal operation mode of the substation is disconnected and is purely standby.