Course project.: Design and calculation of power supply systems of industrial enterprise

Contents

INTRODUCTION

INITIAL DATA FOR COURSE WORK

CALCULATION OF ELECTRICAL LOADS

DRAWING UP OF POWER SUPPLY DIAGRAM

SELECTION OF LINE PARAMETERS SUPPLYING INDIVIDUAL WORKSHOPS

SELECTION OF POWER STEP-DOWN TRANSFORMER 6/0.4 KV

SELECTION OF CURRENT TRANSFORMERS

CALCULATION OF SHORT-CIRCUIT CURRENTS

CALCULATION OF CURRENT SETPOINTS FOR HIGH-VOLTAGE CONSUMERS

CALCULATION OF REACTIVE POWER TO BE COMPENSATED AND SELECTION OF REACTIVE POWER COMPENSATION UNIT

SELECTION AND CHECK OF ELECTRICAL DEVICES

CONCLUSION

LIST OF LITERATURE USED

APPLICATIONS

Summary

In the course work, work was carried out on the compilation of the power supply scheme of an industrial enterprise, the selection of power transformers, the selection of current transformers, the selection of a reactive power compensation unit, the selection and verification of electrical devices, the calculation of current settings, the selection of power lines that supply individual workshops.

The work contains: pages 33, figures 1, electrical diagram -3, tables -6

Introduction

In order to correctly design the power supply schemes of an industrial enterprise, rationally applying the knowledge gained at the university, it will be necessary to carry out this course work. When performing this course work, it will help us learn to correctly, compile power supply schemes for industrial enterprises, calculate current protection settings, select cable lines, transformers, relay protection devices according to known parameters.

Generation of power supply diagram

Power supply to industrial enterprises is carried out, as a rule, from substations of the system. Due to the presence at industrial enterprises of consumers of the 1st category in terms of reliability of power supply, their electricity is supplied through two air dead end radial power lines. A typical solution is to place two power transformers on the GPP. In case of failure of one of power lines or one power transformer, the remaining power lines and transformer, taking into account the permissible G-load under the conditions of mines or mines, shall provide transmission of the full design load, in conditions of open mining, it is allowed to reduce transmission to 75% of the design load. To reduce the cost of installing switching equipment at the GPP input, the installation of separators and shorts is provided. In emergency modes, switching of dead end power lines is performed by switches installed at the beginning of power lines at the substation of the system. To increase the reliability of power supply, a jumper with disconnectors and switches is provided between power lines, which allows you to keep both power transformers of the GPP in operation in case of failure of one of the power lines. The PSG node is a busbar system through which all the current consumed by the substation flows. For each voltage of secondary windings of power transformers, a single partitioned system of busbars is usually used on the GPP. The lower voltage winding of the power transformer and electric receivers are connected to each section by means of switches, the calculated power of which is approximately equal to half of the calculated power of the enterprise. Category 1 consumers are provided with separate inputs from different sections of prefabricated tyres. An inter-section switch is installed between the sections, which provides automatic entry of reserve (ATS). To limit lightning and switching surges, arresters are installed at the GPP input. In order to increase electrical safety, ensure reliable operation of earth fault protection devices and improve the voltage mode, surface and underground consumers in coal and shale shafts are supplied from various windings of lower voltage of power three-winding transformers or 6/6.3 kV separation transformers are used. The drawn-up power supply scheme should ensure the execution of operational switching, as well as switching related to the withdrawal of individual devices for repair. Taking into account these requirements and the initial data of the course project, we will draw up a power supply scheme, the drawn up scheme is presented in annex 1.