Power source regulator for wireline cable system

• US 6,841,984 B2
• Filed: 01/09/2003
• Issued: 01/11/2005
• Est. Priority Date: 09/11/2001
• Status: Expired due to Term

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Hernandez, Ramon
• Primary Examiner(s): Han, Jessica
• Application Number:
  US10/339,045
• Publication Number:
  US 20030098673A1
• Time in Patent Office: 733 Days
• Field of Search: 323/324, 323/246, 323/282, 323/284, 323/285, 379/412, 379/413
• US Class Current: 323/324
• CPC Class Codes: E21B 47/12 Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
• CPC Class Codes: H04L 25/02 Details ; arrangements for supplying electrical power along data transmission lines systems for transmitting signals via power distribution lines H04B3/54

Abstract

A system (150) for controlling voltage supplied to a transmission line system. System (150) includes a transmission cable (134) having a characteristic impedance and a load impedance connected at its distal end. A power source (154) is connected to transmission cable (134). Power source (154) is configured to receive a voltage signal input (157) and to drive a source voltage V_S based thereon. A feedback unit (155) is configured to receive the power source current (I_S) as an input and further configured to generate a feedback voltage (V_F) that varies with I_S. A set voltage unit (152) is configured to produce a substantially constant voltage (V_set) and an adder (153) is configured to add the set voltage (V_set) to the feedback voltage to generate the voltage signal (157) that provides the input to power source (154). The feedback unit (155) may include an impedance element (156) comprising a digital signal processor or other suitable circuit that models the short circuit impedance of the transmission line.

Claims

1. A method of controlling load voltage in an electronic system including a transmission cable comprising:

driving the electronic system with a source voltage (VS) derived by a voltage source from an input to the voltage source;

modeling a characteristic of the transmission cable;

measuring an input variable to the electronic system;

applying the measured variable to the cable model to generate a feedback voltage (VF); and

combining the feedback voltage signal with a set voltage (Vset) to produce the source input.

2. The method of controlling load voltage in an electronic system including a transmission cable of claim 1 wherein the input variable is source current (I_S) produced by the voltage source.

3. The method of controlling load voltage in an electronic system including a transmission cable of claim 2 wherein the combining step comprises:

adding the feedback voltage signal to a set voltage signal indicative of a set voltage (V_set) to produce the voltage source input.

4. The method of controlling load voltage in an electronic system including a transmission cable of claim 1 wherein the combining step comprises:

adding the feedback voltage signal to a set voltage signal indicative of a set voltage (V_set) to produce the voltage source input.

5. An electronic system comprising

a transmission cable having a characteristic impedance Z₀ and a load impedance Z_H at a distal end of the cable;

a power source connected to the transmission cable and configured to receive a signal input and to drive a source voltage V_S based thereon;

a feedback unit configured to receive an input variable to the electronic system and further configured to generate a feedback voltage signal based thereon;

a set voltage unit configured to produce a substantially constant voltage signal; and

an adder configured to add the set voltage signal to the feedback voltage signal to generate the voltage signal that provides the input to power source.

6. The electronic system of claim 5 wherein the input variable is source current (I_S) produced by the voltage source.