GRADIENT POWER SUPPLY ENERGY CONSUMPTION REDUCTION TECHNIQUE
Publication Date: 2012-Sep-23
The IP.com Prior Art Database
The invention proposes a technique involving protocols based controller to reduce gradient power supply energy consumption. The protocols based controller adjusts gradient output voltage before bus pumping and disable or lower switching density during periods when no protocol is running. As a result, preload power consumption and switching power are reduced in the gradient power supply subsystem.
FIELD OF INVENTION
The invention generally relates to a Magnetic Resonance Imaging (MRI) system and more particularly to a gradient power supply subsystem in a MRI system.
BACKGROUND OF THE INVENTION
Gradient power supply is an important subsystem used in magnetic resonance imaging (MRI) system. The gradient power supply provides specific voltage for a gradient amplifier to generate required current. Further, a protocol in a gradient power supply subsystem determines series of output current of gradient amplifier. Hence, the protocol determines behavior of gradient power supply. However, there is resistive loss in the gradient power supply, which is referred to as power loss.
There are two kinds of power loss in gradient power supply. One of them is preload power loss. Preload is used to reduce bus pumping during unbalanced protocols running. The technique of utilizing preload in the gradient power supply is effective. However, the preload connected to gradient power supply output capacitor continuously consumes power of about 0.5-0.6KW.
Another kind of power loss is switching loss while no protocols are being run. In real world applications, resonance scanning takes place for about 6 days per week of use. In one day, 16 hours scanning and out of 45 minutes, 25 minutes scanning takes place. Hence, for a certain long period of time, gradient power supply does not need to output normal power. Therefore, either switching is disabled or switching density is adjusted low to save switching energy.
Therefore, there is a need in the art for a technique which reduces gradient power supply energy consumption.
BRIEF DESCRIPTION OF THE INVENTION
The invention proposes a technique for reducing preload and switching loss in a gradient power supply subsystem. The technique involves protocols based controller to reduce gradient power supply energy consumption.
DETAILED DESCRIPTION OF THE INVENTION
A protocol based controller technique is proposed herein. The technique reduces gradient power supply energy consumption. Initially, the protocol based controller translates protocol current waveform into voltage reference waveform. The vo...