Method and system for diagnosing a technical installation

• US 20020083372A1
• Filed: 01/28/2002
• Published: 06/27/2002
• Est. Priority Date: 07/28/1999
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Adam, Gottfried
• Granted Patent: US 6,910,156 B2
• Time in Patent Office: Days
• US Class Current: 714/37
• CPC Class Codes: G05B 23/0248 Causal models, e.g. fault tree; digraphs; qualitative physics
• CPC Class Codes: G05B 23/0278 Qualitative, e.g. if-then rules; Fuzzy logic; Lookup tables; Symptomatic search; FMEA
• CPC Class Codes: Y10S 706/914 Process plant

Abstract

A diagnostic method and system for a technical installation establish the cause of a fault event. A reliable, flexible and simple possible way of diagnosing an installation is provided by placing state variables that characterize an operating state of the technical installation in a dependency tree and establishing a fault path in the dependency tree by linking change directions of diagnostic parameters contained in the independency tree.

Claims

1. A diagnostic method for a technical installation for determining a cause of a fault event described by a fault state variable, the method which comprises:

establishing an operating state of the installation defined by state variables, by determining diagnostic parameters each characterizing one of the state variables;

compiling a dependency tree containing at least some of the diagnostic parameters by configuring the dependency tree with the following hierarchical levels numbered Hn, where n=1, 2, . . . ;

a first hierarchical level containing a fault diagnostic parameter characterizing a fault state variable,

a second hierarchical level, following the first hierarchical level, and containing diagnostic parameters defining state variables acting directly on the fault state variable,

a hierarchical level Hn+1, following a given hierarchical level Hn, and containing diagnostic parameters defining state variables acting directly on the state variables characterized by the diagnostic parameters at the given hierarchical level Hn;

determining a fault path in the dependency tree starting from the fault diagnostic parameter, by identifying a responsible diagnostic parameter at the hierarchical level Hn+1 depending on one of a magnitude and a change direction of a diagnostic parameter at the given hierarchical level Hn; and

inferring a cause of the fault from the responsible diagnostic parameter identified in the identifying step at a last one of the hierarchical levels.

2. The diagnostic method according to claim 1, which further comprises allocating one of a rising, a falling and a constant change direction to each diagnostic parameter at the hierarchical level Hn+1, for each diagnostic parameter at the given hierarchical level Hn, as a function of a predefined change direction of the respective diagnostic parameter at the given hierarchical level Hn, and establishing the fault path by agreement between measured change directions of the diagnostic parameters and the allocated change directions.

3. The diagnostic method according to claim 1, wherein the technical installation is a turbine installation.

4. The diagnostic method according to claim 3, wherein the turbine installation is a gas turbine installation.

5. The diagnostic method according to claim 3, wherein the turbine installation is a steam turbine installation.

6. The diagnostic method according to claim 3, wherein the turbine installation is a combined gas and steam turbine installation.

7. The diagnostic method according to claim 1, which further comprises establishing the cause by utilizing a wide area network.

8. The diagnostic method according to claim 1, which further comprises establishing the cause by utilizing the Internet.

9. A diagnostic system for a technical installation for determining a cause of a fault event described by a fault state variable, the diagnostic system configured to:

establish an operating state of the installation defined by state variables, by determining diagnostic parameters each characterizing one of the state variables;

compile a dependency tree containing at least some of the diagnostic parameters by configuring the dependency tree with the following hierarchical levels numbered Hn, where n=1, 2, . . . ;

a first hierarchical level containing a fault diagnostic parameter characterizing a fault state variable,

a second hierarchical level, following the first hierarchical level, and containing diagnostic parameters defining state variables acting directly on the fault state variable,

a hierarchical level Hn+1, following a given hierarchical level Hn, and containing diagnostic parameters defining state variables acting directly on the state variables characterized by the diagnostic parameters at the given hierarchical level Hn;

establish a fault path in the dependency tree starting from the fault diagnostic parameter, by identifying a responsible diagnostic parameter at the hierarchical level Hn+1 depending on one of a magnitude and a change direction of a diagnostic parameter at the given hierarchical level Hn; and

determine a cause of the fault from the responsible diagnostic parameter identified in the identifying step at a last one of the hierarchical levels.

10. A diagnostic system for a technical installation for determining a cause of a fault event described by a fault state variable, the diagnostic system comprising:

means for establishing an operating state of the installation defined by state variables, by determining diagnostic parameters each characterizing one of the state variables;

means for compiling a dependency tree containing at least some of the diagnostic parameters by configuring the dependency tree with the following hierarchical levels numbered Hn, where n=1, 2, . . . ;

a first hierarchical level containing a fault diagnostic parameter characterizing a fault state variable,

a second hierarchical level, following the first hierarchical level, and containing diagnostic parameters defining state variables acting directly on the fault state variable,

a hierarchical level Hn+1, following a given hierarchical level Hn, and containing diagnostic parameters defining state variables acting directly on the state variables characterized by the diagnostic parameters at the given hierarchical level Hn;

means for establishing a fault path in the dependency tree starting from the fault diagnostic parameter, by identifying a responsible diagnostic parameter at the hierarchical level Hn+1 depending on one of a magnitude and a change direction of a diagnostic parameter at the given hierarchical level Hn; and

means for determining a cause of the fault from the responsible diagnostic parameter identified in the identifying step at a last one of the hierarchical levels.