RU192719U1 - Complete power distribution and conversion device - Google Patents

Abstract

The technical solution relates to the field of converting electronic equipment and can be used to create solar inverters for autonomous sources of electricity. The essence of the claimed technical solution lies in the fact that the device additionally contains ventilation compartments for inverters and a transformer presented in a dry type with a split secondary winding, consisting of from n-windings connected to the compartment of power inverters. The power inverter compartment contains inverter and sine filter cells connected to the control cabinet via an optical communication line. Also, the cells contain dedicated air channels that allow the cells to be purged, with air supply and exhaust through the ventilation compartments, equipped with air filters and dampers that regulate air inflow and outflow, as well as air recirculation inside the block box. Technical result achieved by the implementation of the claimed utility model , is to increase the operational characteristics of the complete device for the distribution and conversion of electricity, such as increasing the level of efficiency of the inverter to 98%, reducing the level of x, both at the input and output, the expansion of the range of operating temperatures within –60 ° С + 40 ° С. 2 s.p. crystals, 6 FIG.

Description

The technical solution relates to the field of converting electronic equipment and can be used to create solar inverters for autonomous sources of electricity.

Solar inverters are well known in the art. Standard elements for such devices are: DC module (input signal), inverter module and AC module (output signal) connected to the transformer.

The DC module includes a number of photovoltaic cells that provide direct current (DC) input to power inverters. The power inverter module uses a series of electronic switches, in particular isolated bipolar transistors (IGBTs), to convert direct current at the input to alternating current (AC) at the output.

For inverters supplying electricity to the electric network, the AC module provides an alternating current output in the form corresponding to the current of the public consumption electric network.

Very often, solar power plants are installed in large areas with difficult climatic conditions, which causes certain difficulties in their maintenance and requires the use of equipment adapted for continuous autonomous operation in difficult operating conditions.

Leading manufacturers of solar inverters use the device layout in the form of a block box, which allows you to use a complete device for the distribution and conversion of electricity in various climatic conditions, providing protection from harmful environmental factors.

The prior art multilevel step-up three-phase converter of constant voltage to three-phase industrial frequency, RF patent No. 2537506 from 11/19/2012, IPC H02M 7/497. The device described in patent No. 2537506 contains a common constant voltage source in the form of a solar battery connected to a single-phase bridge autonomous inverter, and a three-phase cell-type frequency converter, consisting of a multi-winding transformer, rectifier-inverter cells, a control system, current sensors, voltage and an adjustable regulator quantities. A single-phase bridge autonomous inverter is made high-frequency, a three-phase cell-type frequency converter is connected to its output, a transformer of which is made by a high-frequency single-phase multi-winding and its secondary windings are respectively connected to the inputs of single-phase rectifier-inverter cells consisting of series-connected single-phase rectifier and inverter. The secondary windings of the matching transformer are designed to be connected to the power grid of the power system.

The disadvantages of this technical solution include the use of a single-phase rectifier and inverter with their series connection, which can lead to a significant loss of device power in the event of failure of one of these structural elements.

Also, from the patent for the invention No. 2606383 of 09/01/2015, IPC H02M7 / 493, an inverter for solar power plants is known containing a block of solar batteries connected to an energy converter. The first parallel-connected power module of the energy converter is connected to the first primary winding of the transformer, the second parallel-connected power module of the energy converter is connected to the second primary winding of the transformer, the primary windings of the transformer are connected counter to each other. The secondary winding of the transformer is connected in parallel to a series-connected resistor and supercapacitor.

The disadvantages of the described technical solution include the low reliability of the device, because when one of the power modules fails, the inverter loses 50% of the power.

From US Patent No. US9420732B2 of June 13, 2012, a solar inverter is known comprising a housing comprising a cooling module, a direct current module, an inverter module and an alternating current module. The cooling module, DC module, inverter module and AC module are installed side by side in the housing. The DC module contains input, switch and output. The inverter module comprises an input connected to the output of the DC module and an output, the inverter module being configured to convert DC power at the input of the inverter module to AC power at the output of the inverter module.

The AC module contains an input connected to the output of the inverter module. An AC module disconnect switch is provided on the outside of the chassis. The cooling module is configured to pump coolant around the solar inverter to cool one or more elements of the DC module, inverter module, and / or AC module.

The disadvantages of the described technical solutions include the implementation of the device with a liquid cooling system, which significantly complicates its design and cost, also this system needs regular maintenance, which may limit the possibility of its operation. Solar inverters manufactured by ABB are known from the prior art, in particular, the ABB megawatt station PVS800-MWS - 1 to 2.4 MW inverter, known from the manufacturer's official website: http: //www.abb.de/abblibrary/DownloadCenter/, is accepted as the closest analogue. ? showresultstab = true & QueryText = wechselrichter (08.13.2018).

According to the technical description, the complete electric power distribution and conversion device connected to a direct current source contains a housing based on a standard 40-f container in the form of a block box, divided into input commutation and output cell compartments, as well as power inverters and transformer compartments with a common system heating and ventilation with microprocessor control system. The transformer is implemented in a dry design with two secondary windings connected respectively to two power modules.

The disadvantages of the described technical solution include the implementation of the device in a housing made of steel, which complicates the temperature control inside the housing and requires the installation of more powerful ventilation and heating systems. Also, the implementation of the device with two power modules significantly reduces the reliability of its operation, since when one of the power modules fails, the inverter loses 50% of the power.

The technical problem to which the claimed utility model is directed is to create a reliable and easy-to-use complete electric power distribution and conversion device in the performance of a high-power block box equipped with affective heating and ventilation systems.

The technical result achieved from the implementation of the inventive utility model is to expand the range of operating temperatures within -60 + 40 ° C.

The essence of the proposed technical solution lies in the fact that the compartments of the transformer and power inverters are located next to each other and are additionally made each with its own ventilation compartment. The transformer compartment is arranged to accommodate a dry type transformer with a split secondary winding consisting of n-windings and forced air cooling of the transformer inside the compartment. The power inverter compartment is arranged to accommodate the cells of the power inverters and the sine filter, while the cells of the power inverters contain dedicated air channels that allow them to be purged with air supply and exhaust through its ventilation compartment. The ventilation compartments of the transformer and cells of the power inverters are equipped with exhaust centrifugal fans with adjustable rotation speed and air electric heaters, as well as air filters and dampers made with the possibility of regulating the air inflow and outflow, as well as providing air recirculation inside the block box, while the air electric heaters provide heating both the supply air and the internal volume of the block box.

The secondary winding of the transformer contains n-windings, and n≥3 in particular of the secondary windings can be six or more, also one of these windings is a winding of the device's own needs.

The block box is equipped with a heating, ventilation, lighting, fire alarm and fire extinguishing system. The body elements are made in the form of a hinged three-layer sandwich panels.

Also, according to one possible embodiment of the invention, the device comprises an operator compartment with a control cabinet containing a microprocessor controller, control units for pre-charging the power cells of the inverter compartment, transformer pre-magnetization units, digital inputs / outputs, analog inputs / outputs, digital RS-485 interfaces, Control elements of the climate control system, as well as automatic switching devices.

Also, according to the claimed invention, the compartment of the output cell is equipped with disconnectors, earthing switches of power and measuring circuits on the high voltage side, withdrawable circuit breaker, as well as a system for measuring currents and voltages.

The essence of the proposed technical solution is illustrated, but not limited to the following graphic materials:

figure 1 - diagram of the transformer windings;

figure 2 - block box, front view;

figure 3 - layout of the compartments in the block box;

figure 4 - the housing of the power cell inverter;

5 is a diagram of the movement of air flows in the recovery mode;

6 is a diagram of the movement of air flows in ventilation mode.

A complete device for the distribution and conversion of electricity is designed to convert electric energy received from a direct current source into alternating current for transferring it to an energy system with a frequency of 50 Hz, voltage of 10 kV and more.

As a voltage source can be used:

solar panels based on photovoltaic modules;

rechargeable batteries;

supercapacitor batteries;

DC generators.

The technical solution can be applied at power generating stations. The design of the described embodiment of the technical solution is optimized for labor costs for installation, commissioning and maintenance. The execution of the block box does not require additional construction documentation and expertises for installation at the facility.

The inventive device converts direct current voltage of 680 ... 975 V, in a three-phase voltage of 10 kV or more, industrial frequency.

The technical solution implements the principle of "direct-alternating current" with one output power transformer. Conversion from direct to alternating current is performed by power units (cells) built on IGBT transistors.

The transformer is presented in a dry type design with a split secondary winding (Fig. 1), consisting of n-windings connected to the compartment of power inverters, with n≥3, also one of these windings is a winding of the device's own needs. The specified transformer has forced air cooling inside the compartment. The parallel inclusion of power cells allows for a low level of interference. The microprocessor control system is implemented on the basis of a universal microprocessor controller.

The complete device 1 (Figs. 2, 3, 4) of the distribution and conversion of electricity, contains a frame body 2 in the execution of a block box, the body elements are made in the form of a hinged three-layer sandwich panels.

The device case is divided into compartments:

operator 3;

input switching 4;

output cell 5;

power cells of inverters 6 and transformer 7 with an automated heating and ventilation system with a microprocessor control system;

ventilation of inverters 8 and transformer 9.

The cells of the power inverters and the sine filter are connected to the control cabinet 10 installed in the operator compartment 3 by means of an optical communication line. The control cabinet contains a microprocessor controller, a microprocessor control system including control units for pre-charging the power cells of the inverter compartment, transformer pre-magnetization units, digital inputs / outputs, analog inputs / outputs, digital RS-485 interfaces, climate control elements, and automatic switching devices (not shown in the images).

The input switching compartment 4 provides the reception / transmission of voltage from direct current sources to the cell blocks of power inverters 6, as well as protection against high voltage, for example, in the event of a lightning strike. The specified compartment according to one of the possible variants of implementation contains electromagnetic compatibility filters, current sensors, insulation monitoring elements, safety devices with specified current limiting characteristics (not shown in the images).

The compartment of the output cell provides voltage distribution and switching. The specified compartment, according to possible options for implementing the technical solution, can be equipped with disconnectors-earthing switches of power and measuring circuits on the high-voltage side, a circuit breaker and a system for measuring currents and voltages.

The compartments of the power cells of the inverters 6 and the transformer 7 with a microprocessor control system are installed next to each other, with each of the compartments having its own ventilation compartment 8.9. The cells 11 (Fig. 4) of the power inverters contain dedicated air channels 12 for blowing the cells, with air supply and exhaust through the corresponding ventilation compartment 8. Each of the ventilation compartments is equipped with air filters 13 and dampers 14, configured to control the inflow / outflow of air, as well as air recirculation inside the block box. Moreover, these compartments are equipped with exhaust centrifugal fans 15 with adjustable power, air electric heaters; system for measuring and adjusting temperature and humidity.

Air electric heaters provide heating of both supply air and the internal volume of the block box. These electric heaters are structurally constructed on the basis of the assembly of a tubular electric heater.

The scheme of movement of air flows in the ventilation compartments is shown in Fig.5,6. According to one possible implementation option, the ventilation system can operate as in a recuperation mode, providing air recirculation inside the block box (Fig. 5) while maintaining the selected heat inside, in which the external adjustable shutters 14 are closed and the internal 16 are open. At the same time, in the ventilation mode, the external flaps 14 are open, and the internal 16 are closed, providing an influx of cold air with a heated outlet.

The claimed technical solution contributes to the achievement of the specified technical result, providing reliability and easy-to-use complete power distribution and conversion device in the execution of a block box equipped with affective automated heating and ventilation systems, providing an extension of the operating temperature range of -60 + 40 ° C.

Claims (3)

1. A complete device for the distribution and conversion of electricity associated with a direct current source, consisting of a housing in the form of a block box, divided into compartments of the input switching and output cell, as well as compartments of the power cells of inverters and transformers equipped with a ventilation system, characterized in that the compartments of the transformer and power inverters are located next to each other and are additionally made each with its own ventilation compartment, the transformer compartment is arranged to accommodate the transformer dry type design with a split secondary winding consisting of n-windings and forced air cooling of the transformer inside the compartment, the power inverter compartment is arranged to accommodate the power inverters and the sine filter, while the power inverters contain dedicated air channels that allow them to be purged with air supply and exhaust through its ventilation compartment, ventilation compartments of the transformer and power inverter cells are made with the possibility of equipping with exhaust centrifugal vents adjustable speed radiators and air electric heaters, as well as air filters and dampers made with the possibility of regulating air inflow and outflow, as well as providing air recirculation inside the block box, while air electric heaters provide heating of both the supply air and the internal volume of the unit boxing. 2. The complete device for the distribution and conversion of electricity according to claim 1, characterized in that the secondary winding of the transformer contains n-windings, and n fulfills the conditions n≥3, also one of these windings is a winding of the device's own needs. 3. The complete device for the distribution and conversion of electricity according to claim 1, characterized in that the housing elements are made in the form of a hinged three-layer sandwich panels.

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