#open-loop

Types of Piping Systems closed-loop, open-loop, and once-thru

Understanding of the three basic types of piping systems: closed-loop, open-loop, and once-thru

Closed-Loop (Evaporator)

In a closed-loop piping system, the water is contained within a closed piping system, or loop, through which it circulates. While there may be some nominal contact with the air depending on the type of tank used, the system is considered closed to the environment.…

What is LLRF doing?

Control and maintain the specified phase and amplitude stability of accelerating field in RF cavity during beam traveling. Also maintain the filling stage of the RF pulse.

The stability requirement varies in different accelerators, determined by specific application. e.g. XFEL:0.01% and 0.01° ; SARAF: 0.1% and 0.1° ; SNS: 0.5% and 0.5° ; JPARC: 1% and 1°.

Why need LLRF?

Bec…

A common method to control the angular velocity of an electrical machine with a power inverter is to adjust the amplitude of the stator voltage to be in proportion to the speed of the rotor. This ensures a constant flux linkage distribution.

This technique is knows as ‘Volt/Hz = const. control’. It is an open-loop control method that does not require feedback signals such as the measured stator currents or the dc-link voltage of the power inverter.