Optical Pump Unit Throttle-Back for Subsea Repeater Power Loss
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Solution Overview
Problem
Existing subsea optical communication systems face challenges in efficiently providing power to Erbium doped fiber amplifiers (EDFAs) in repeaters, especially in long-haul systems with dozens of repeaters.
Innovation Solution
The proposed solution involves an optical pump unit (OPU) with a line voltage transistor, a DC-to-DC converter, an optical pump assembly, a current control assembly, a throttle back control assembly, and a current/voltage sensor. This configuration allows for efficient power management by monitoring line current and voltage drops, and throttling back power when necessary to prevent voltage collapse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If high voltage DC current is transmitted through electrical cables to power repeaters in long-haul subsea systems, then power can be delivered to numerous repeaters across thousands of kilometers, but voltage drops and power loss increase significantly over distance
Solution Approach 1:
The patent segments the power delivery system by introducing individual voltage regulation stages at each repeater location. Instead of transmitting high voltage through the entire cable length, each repeater has its own voltage regulator that steps down the voltage locally, dividing the long transmission path into multiple controlled segments and reducing cumulative voltage drops.
Solution Approach 2:
The patent introduces voltage regulators as intermediary devices between the power source and the optical pump units. These regulators act as mediators that convert high voltage DC current into appropriate lower voltages for powering EDFAs, eliminating the need to transmit high voltage over the entire distance and reducing power loss in the cable.
2Reliability
If optical pump units continuously operate at full power to amplify optical signals, then signal amplification is maintained, but power consumption increases
Solution Approach 1:
The patent implements dynamic power management by making the optical pump unit's power consumption adjustable based on actual system needs. The voltage regulator enables continuous adjustment of power delivery to match the amplification requirements, allowing the system to operate at lower power when full amplification is not needed while maintaining reliability when required.
Solution Approach 2:
The patent changes the power parameter of the optical pump unit dynamically through voltage regulation. By adjusting the voltage supplied to the EDFAs based on monitoring signals and system conditions, the system can optimize the balance between signal amplification quality and power consumption, rather than operating at fixed full power.
3Use of energy by stationary object
If voltage is increased to compensate for drops in long cable spans, then power delivery to distant repeaters improves, but power loss in the cable increases due to I²R losses
Solution Approach 1:
The patent segments the voltage regulation function across multiple repeater locations rather than boosting voltage at the source for the entire span. Each repeater independently regulates its own voltage, converting the single high-voltage transmission problem into multiple low-voltage local delivery problems, thereby reducing I²R losses in the cable.
Solution Approach 2:
The patent introduces voltage regulators at each repeater as intermediary devices that perform local voltage conversion. These intermediaries eliminate the need to transmit high voltage over long distances by converting to lower voltages locally, reducing the current required and thereby reducing I²R power losses in the cable.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution reduces power consumption and saves energy by optimizing voltage drops and maintaining power at nominal line currents, resulting in potentially large power savings, such as a 34% reduction in total system power as demonstrated in simulations.
Implementation Method 1
The optical pump unit may control operation of Erbium doped fiber amplifiers (EDFAs) that are used to amplify optical signals being transmitted through a given repeater
Implementation Method 2
a current/voltage sensor, to monitor a line current and voltage drop in the optical repeater
Data Source
AI summary
An optical pump unit may include a line voltage transistor, coupled between an input side and an output side of the optical pump unit. The optical pump may further include a DC-to-DC converter, having an input side coupled to the line voltage transistor; an optical pump assembly, coupled to an output side of the DC-to-DC converter; a current control assembly, coupled to the optical pump assembly; a throttle back control assembly, having an output coupled to the current control assembly, and a current/voltage sensor, to monitor a line current and voltage drop in the optical repeater, and being coupled to an input of the throttle back control assembly. As such, the throttle back control assembly may be configured to send a signal to the current control assembly to reduce a power at the optical pump assembly when a decrease in line current or voltage drop takes place.