load sharing circuit

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