Power supply system: design, device, operation. Autonomous power supply systems

The improvement of the quality of the maintenance of buildings and industrial complexes led to the widespread use of electric power sources and related infrastructure. In modern enterprises, the functions of power supply systems assume the greatest responsibility, since the slightest failure in the supply of equipment can lead to a violation of production processes. And this is only part of the risks that need to be minimized at the design stage of the electricity supply system project. No less important are the issues of optimizing this infrastructure, since the costs of energy resources, as a rule, become the most expensive item in the estimate for the content of enterprises.

Purpose of power supply systems

Usually specialists, along with the primary tasks of such systems, distinguish their composition and characteristics. But the separation of these parameters will allow more accurate determination of the components and tasks of power supply systems. Their main purpose is to provide consumers with energy resources. The latter can be a small private object, and a large-scale regional enterprise. By and large, the power supply system acts as a connecting component between the source and the energy receivers.

Structure and components

The power supply complex can be represented as a three-part system. It is directly a power source that distributes infrastructure and means of supplying electricity. For interconnection between these components, the power supply system provides a wide range of equipment and auxiliary elements:

• Power lines (provide power transmission to receivers);
• Step-down substations (perform primary conversion of energy from its sources);
• Distribution stations (perform an important function of network distribution of energy to supply several consumers);
• Converter installations (prepare the electric flow for end use);
• Air lines and cables (connecting elements that form a network in the power supply infrastructure);
• Current conductors (ensure the final supply of energy to its receivers).

Varieties of generators

Power stations are mostly designed for autonomous power supply systems of various types. These are devices that include a motor that generates a current. Modern power plants operate on three main types of fuel - gasoline, gas and diesel.

Generators on gasoline fuel are usually used as reserve systems and are calculated for short periods of operation. Such stations are cheaper and easier to maintain, but high fuel costs do not allow them to be used in intensive regimes. A more powerful diesel power supply system benefits from low maintenance costs (20% less compared to gasoline equivalents), but equipment and installation costs are more expensive. Gas power supply found its place in the maintenance of large industrial facilities - the advantages of such infrastructure include price availability of fuel and durability.

Design

In the process of creating a model of the future power supply system, several stages are required, including the development of a plan for power electricians, tracing, location and equipment parameters. Modern design of power supply systems includes the following works:

• Creation of a plan for placing equipment;
• Drawing up of schemes of feeding and distribution networks;
• A selection of cables, design work on their parameters;
• Creation of cable reporting;
• Wire routing;
• Specification development;
• Preparation of the layout of wiring and related equipment.

When performing the majority of design operations, specialists should determine the electrical loads and conduct electric network calculations, which will serve for transmission and distribution of electricity between its receivers. Also take into account the demand factors and installed capacity.

Choice of equipment

When the project is ready, the specialists pass to the selection of technical means that realize the power supply system. Basic data, on the basis of which the equipment is selected, gives the design of power supply systems based on calculations and operating conditions. The components of the complex will determine its durability and reliability. To date, the list of equipment for such purposes includes cable-conductor products, high-voltage equipment, explosion-proof electrical engineering, lighting products, generators and power stations, transformer plants, power electronics and various components.

Installation

This is the final stage in the creation of a power supply complex, which includes the assembly and installation of equipment. Installation takes into account the project data and the characteristics of the enterprise - so, in the case of the implementation of the task at production facilities, specialists consider the possibility of stage-by-stage installation of individual components without the need to stop the work process. At the same stage, automation of power supply systems is carried out at the expense of control panels and special controllers. Then commissioning operations are performed and necessary amendments are made to the maintenance and operation schedule.

Principles of management and operation

When considering the operation of power supply systems, it is important to take into account the fact that servicing energy sources and associated electrical equipment should generate as much resource as required by consumers. In other words, the work of power plants and networks is calculated on possible changes in the load of the receivers. Rational operation of power supply systems provides for special training of dispatch center personnel who will be able to accurately monitor the demand of receivers for electricity. Guided by these indicators, the service selects the optimal number of generators with reduced loads or, on the contrary, starts backup stations while increasing energy needs.

It is important to take into account that the quality of service of the power system depends on the productivity and safety of work processes in the enterprise. Disruptions in electricity supply can cause accidents, downtime on conveyors and other unpleasant situations and phenomena, as a result of which the appearance of victims and the under-production of manufactured products are not ruled out.

Criteria for the quality of electricity supply

The responsibility of the systems providing food for the energy resources of enterprises necessitates the maintenance of sufficient indicators of their performance. In this connection, the maintenance of the supply plants is based on the following principles:

• Ensuring the uninterrupted operation of generators, networks and associated power supply components. By the way, reliability of power supply systems is one of the primary assessments of its quality, as well as maintainability with durability.
• Stability of the implementation of the plan for electricity generation and its subsequent distribution with coverage of the required maximums for consumer loads.
• Preservation of the quality of energy supplied to receivers. It must meet the requirements of the supplying electrical equipment in frequency and voltage.

To achieve optimal working conditions, the power supply system is controlled by dispatching consoles. The latter, in turn, are provided with tools, through which control, adjustment, management of power plants, power lines and lowering substations are carried out.

Modes of operation

Any power supply complex provides for individual means of protection in case of emergency situations. As a rule, these are relay protection systems, which led to the separation of modes of operation of power systems into three types: normal, emergency and post-emergency. The first mode is characterized by uninterrupted power supply. In such operating conditions, the power supply system of industrial enterprises supplies the resource in sufficient quantity and of the required quality. In emergency mode, the normal operation of the system is disrupted and lasts until the damaged component is also disabled. The post-emergency format of the power supply system continues until the normal operation of the entire complex is restored.

Classification of power supply systems

There are several principles for the separation of power systems that supply consumers with electricity. Depending on the source, the power supply system can be electrochemical, diesel-electric and nuclear. Various such complexes are also in configuration, for example, they are centralized, decentralized and combined. No less significant in the classification and characteristics of the current, constant and variable.

Power supply systems are used in different conditions and at various sites. In this regard, it is necessary to take into account their mobility (stationary, portable and portable) and belonging to the consumer. But, perhaps, the main division belongs to the purpose. So, there are on-duty systems, backup and emergency. The on-duty power supply system of the enterprise performs its functions in a regular manner and, as a rule, is the main source of electricity. Back-up systems, on the contrary, are more often auxiliary power supply infrastructure - to replace the main complex. Emergency power supply usually provides for the possibility of servicing the most critical facilities within a few hours or days.

Autonomous power supply systems

The concept of autonomous systems comes from the need to insure power supply against possible malfunctions in backbone networks and other force majeure situations. Typically, self-contained power supply systems are used in enterprises with an established production process and the need for uninterrupted power supply. In effect, this is the supply of electricity with independent control. It is important to note that autonomous power supply is longevous, but at the same time it requires higher installation and maintenance costs. On the other hand, this approach justifies itself in view of the reliability and stability of energy supply.