parallel current

параллельная система ИБП
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[Интент]

Parallel Operation: The system shall have the option to install up to four (4) UPSs in parallel configuration for redundancy or capacity.
1. The parallel UPS system shall be of the same design, voltage, and frequency. UPS modules of different size ratings shall be permitted to be paralleled together for purposes of increased capacity or UPS module redundancy. The UPSs in the parallel configuration shall not be required to have the same load capacity rating.
2. Parallel Capacity: With N+0 system-level redundancy, up to 2MW of load can be supported by the system.
3. Parallel Redundancy: With N+1 system-level redundancy, up to 1.5MW of load can be supported by the system, and only the UPS being replaced must be isolated from the source (bypass operation is not required for the entire system during the UPS replacement procedure).
4. Output control: A load sharing circuit shall be incorporated into the parallel control circuits to ensure that under no-load conditions, no circulating current exists between modules. This feature also allows each UPS to share equal amounts of the total critical load bus. The output voltage, output frequency, output phase angle, and output impedance of each module shall operate in uniformity to ensure correct load sharing. This control function shall not require any additional footprint and shall be an integral function of each UPS. The static bypass switches shall be connected in parallel.
5. Parallel System Controls: To avoid single points of failure, the UPS system shall have no single dedicated control system designed to control the operation of the parallel UPS system. Control of and direction of parallel UPSs shall take place via a master/slave relationship, where the first UPS to receive logic power asserts itself as a master. In the event of a master failure, a slave UPS shall take the role of master and assume the responsibility of the previous master UPS. Regardless of which UPS is master or slave, user changes to the system status, such as request for bypass, can be done from any UPS connected to the bus and all UPS on the bus shall transfer in simultaneously.
6. Communication: Communication between modules shall be connected so that the removal of any single cable shall not jeopardize the integrity of the parallel communication system. Load sharing communications shall be galvanically isolated for purposes of fault tolerance between UPS modules. A UPS module's influence over load sharing shall be inhibited in any mode where the UPS inverter is not supporting its output bus. Transfers to and from bypass can be initiated from any online UPS in the system.
7. Display: Each UPS multi-color LCD touch screen user interface shall be capable of using an active touch screen mimic bus to show the quantity of UPS(s) connected to the critical bus, as well as the general status of each UPS, such as circuit breaker status information. Any touchscreen display shall support the configuration of the [entire parallel] system and shall provide event and alarm data for all UPSs in the parallel configuration. A Virtual Display Application shall be available for download to the customer’s computer and shalll support remote monitoring of a complete system with up to 4 UPSs in parallel.
8. Battery runtime: Each UPS must have its own battery solution. The battery solution for the entire system can be a combination of standard and third-party batteries, but each UPS must use only one battery solution – either standard or third-party batteries.
9. Switchgear: A custom switchgear option shall be required for parallel operation.

[Schneider Electric]

Тематики

• источники и системы электропитания

EN

• parallel UPS system

резонанс токов
Резонанс в участке электрической цепи, содержащей параллельно соединенные индуктивный и емкостный элементы.
[ ГОСТ Р 52002-2003]

Тематики

• электротехника, основные понятия

EN

• antiresonance
• current resonance
• inverse resonance
• parallel resonance

фотоэлектрическая установка
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[Интент]

Параллельные тексты EN-RU

Photovoltaic plants

A photovoltaic plant permits to convert the energy associated with solar irradiation into electrical energy of direct type; these plants are constituted by panels of semiconducting material, which can generate electrical power once exposed to the rays of the sun.

Photovoltaic plants can be grid-connected or supply a single load (stand alone plant).

In this last case an accumulator battery shall be present to provide power supply in case of lack of solar radiation.

The basic element of a photovoltaic plant is the photovoltaic cell constituted by semiconducting material (amorphous silicon or monocrystalline silicon); this cell, exposed to the rays of the sun, is able to supply a maximum current Impp at a maximum voltage Vmpp, which a maximum power called Wp corresponds to.

More photovoltaic cells are connected in series to form a string to raise the voltage level; by connecting more strings in parallel, the current level is increased.

For example, if a single cell can provide 5A at 35.5 Vd.c., in order to reach the level of 100A at 500 Vd.c., it is necessary to connect 20 strings in parallel, each of them constituted by 15 cells.

Generally speaking, a stand alone photovoltaic plant is constituted by the following devices:
- photovoltaic array: constituted by the photovoltaic cells suitably interconnected and used for the conversion of sunlight energy into electrical energy;
- charge regulator: it is an electronic device able to regulate charging and discharging of accumulators;
- accumulator batteries: they can provide power supply in case of lack of solar radiation;
- DC/AC inverter: it has the function of turning direct current into alternating current by controlling it and stabilizing its frequency and waveform.

The following figure shows the block diagram of a stand alone photovoltaic plant..
[ABB]

Фотоэлектрические установки

Фотоэлектрические установки осуществляют прямое преобразование солнечной энергии в электрическую. Такие установки состоят из панелей полупроводникового материала, вырабатывающего электрическую энергию под воздействием солнечного излучения.

Фотоэлектрические установки являться частью общей энергосистемы или снабжать электроэнергией отдельную нагрузку (автономную установку).

В последнем случае в состав системы должна входить аккумуляторная батарея, обеспечивающая бесперебойную подачу электроэнергии в случае недостаточного солнечного излучения.

Основной частью фотоэлектрической установки являются фотоэлементы, изготовленные из полупроводникового материала (аморфного или монокристаллического кремния). При облучении солнечными лучами фотоэлемент генерирует максимальный ток Iмакс. при максимальном напряжении Uмакс, что соответствует максимальной мощности Wмакс..

Для увеличения выходного напряжения несколько фотоэлементов соединяют последовательно в ряд. Для увеличения тока несколько рядов соединяют параллельно.

Так, например, если один фотоэлемент может произвести ток 5 А при напряжении 35,5 В пост. тока, то для получения источника электроэнергии с током 100 А при напряжении 500 В пост. тока требуется соединить параллельно 20 рядов по 15 фотоэлементов в каждом.

Обычно автономная фотоэлектрическая установка состоит из следующих устройств:
- фотоэлектрическая батарея: состоит из соединенных между собой фотоэлементов, преобразующих солнечную энергию в электрическую;
- регулятор заряда: электронное устройство, предназначенное для регулирования заряда и разряда аккумуляторов;
- аккумуляторная батарея: обеспечивает электропитание нагрузки при недостаточном солнечном излучении.
- инвертор: преобразует постоянный ток в переменный ток стабильной частоты и формы.

На следующем рисунке показана функциональная схема автономной фотоэлектрической установки
[Перевод Интент]

Тематики

• солнечная энергетика

EN

• photovoltaic plant