Method, apparatus and computer program product for network design and analysis

• US 20060080071A1
• Filed: 11/23/2005
• Published: 04/13/2006
• Est. Priority Date: 06/20/2000
• Status: Active Grant

• Current Assignee: ServiceNow Incorporated
• Original Assignee: International Business Machines SA (International Business Machines Corporation)
• Inventors: Bera, Rajendra Kumar
• Granted Patent: US 8,176,108 B2
• Time in Patent Office: Days
• US Class Current: 703/2
• CPC Class Codes: G06F 30/367 Design verification, e.g. using simulation, simulation program with integrated circuit emphasis [SPICE], direct methods or relaxation methods

Abstract

A first representation of an electrical network includes a first set of simultaneous linear algebraic equations (SLAE'"'"'s). A second representation of an electrical network includes a second set of SLAE'"'"'s. The equations of the SLAE'"'"'s include a number of unknowns and have coefficients for the respective unknowns. A number of the coefficients are expressed in algebraic form. The coefficients of one such equation from one of the sets of SLAE'"'"'s are for respective elements of the set'"'"'s respective electrical network and the unknowns are for respective operating properties of the set'"'"'s respective electrical network. Results are derived in pairs for each unknown of each respective one of the SLAE'"'"'s. The pairs of results are compared in a specified manner to determine a network equivalence. The results are derived from the SLAE'"'"'s and expressed in algebraic form, so that the comparing of the pairs of results includes comparing algebraic expressions.

Claims

1. A method, comprising the steps of:

receiving, by a computer system, first information for a first representation of an electrical network, wherein the first representation of the electrical network includes a first set of simultaneous linear algebraic equations (SLAE'"'"'s);

receiving, by the computer system, second information for a second representation of an electrical network, wherein the second representation of the electrical network includes a second set of SLAE'"'"'s and the computer system stores the first and second information on a computer readable medium, wherein the equations of the first and second sets of SLAE'"'"'s include a number of unknowns and have coefficients for the respective unknowns, a number of the coefficients being expressed in algebraic form, and wherein the coefficients of one such equation from one of the sets of SLAE'"'"'s are for respective elements of the set'"'"'s respective electrical network and the unknowns are for respective operating properties of the set'"'"'s respective electrical network;

deriving, by the computer system, a certain pair of results for each unknown of each respective one of the SLAE'"'"'s, the results being derived from the respective sets of SLAE'"'"'s and stored by the computer system on a computer readable medium; and

comparing, by the computer system, the pairs of results to determine a network equivalence, wherein the results derived from the SLAE'"'"'s are expressed in algebraic form so that the comparing of the pairs of results includes comparing algebraic expressions.

2. The method of claim 1, wherein the first and second network representations are for respective first and second electrical networks and the network equivalence is for equivalence of the first and second electrical networks.

3. The method of claim 1, wherein the first and second network representations are both for a same electrical network and the network equivalence is for equivalence of the first and second representations.

4. The method of claim 1, wherein the deriving of such a pair of results for an unknown of the respective sets of SLAE'"'"'s includes:

forming a first product for a first one of the results in such a pair, the first product including a first part of a first standard form equation derived from the first set of SLAE'"'"'s and second part of a second standard form equation derived from the second set of SLAE'"'"'s; and

forming a second product for a second one of the results in such a pair, the second product including a second part of the first one of the standard form equations derived from the first set of SLAE'"'"'s and a first part of the second one of the standard form equations derived from the second set of SLAE'"'"'s, and wherein the comparing of the pairs of results includes comparing respective ones of such first and second products.

5. The method of claim 4, wherein the equations of the SLAE'"'"'s are of a form:

e _i1 x ₁ +e _i2 x ₂ +e _i3 x ₃ + . . . +e _in x _n =b _i

wherein x_j are the unknowns, e_ij are the coefficients, and b_i are quantities, a first one of the standard form equations derived from the first set of SLAE'"'"'s is of the form;

(l_ii)_kx_i=(r_i)_k

with k=1, (l_ii)₁ forming the first part of the equation and (r_i)₁ forming the second part of the equation, and wherein a second one of the standard form equations derived from the second set of SLAE'"'"'s is of the form;

(l_ii)_kx_i=(r_i)_k

with k=2, (l_ii)₂ forming the first part of the equation and (r_i)₂ forming the second part of the equation.

6. The method of claim 5, wherein a first such product includes (l_ii)₁*(r_i)₂ and a second such product includes (l_ii)₂*(r_i)₁ and the comparing of respective pairs of results includes comparing the products (l_ii)₁*(r_i)₂ and (l_ii)₂*(r_i)₁.

7. A system comprising:

a processor; and

a storage device connected to the processor, wherein the storage device is for storing a program for controlling the processor on a computer readable medium, and wherein the processor is operative with the program to execute the program for performing the steps of;

receiving, by a computer system, first information for a first representation of an electrical network, wherein the first representation includes a first set of simultaneous linear algebraic equations (SLAE'"'"'s);

receiving, by the computer system, second information for a second representation of an electrical network, wherein the second representation includes a second set of SLAE'"'"'s and the computer system stores the first and second information on a computer readable medium, wherein the equations of the first and second sets of SLAE'"'"'s include a number of unknowns and have coefficients for the respective unknowns, a number of the coefficients being expressed in algebraic form, and wherein the coefficients of one such equation from one of the sets of SLAE'"'"'s are for respective elements of the set'"'"'s respective electrical network and the unknowns are for respective operating properties of the set'"'"'s respective electrical network;

deriving a certain pair of results for each unknown of each respective one of the SLAE'"'"'s, the results being derived from the respective sets of SLAE'"'"'s and stored by the computer system on a computer readable medium; and

comparing the pairs of results to determine a network equivalence, wherein the results derived from the SLAE'"'"'s are expressed in algebraic form so that the comparing of the pairs of results includes comparing algebraic expressions.

8. The system of claim 7, wherein the first and second network representations are for respective first and second electrical networks and the network equivalence is for equivalence of the first and second electrical networks.

9. The system of claim 7, wherein the first and second network representations are both for a same electrical network and the network equivalence is for equivalence of the first and second representations.

10. The system of claim 7, wherein the deriving of such a pair of results for an unknown of the respective sets of SLAE'"'"'s includes:

forming a first product for a first one of the results in such a pair, the first product including a first part of a first standard form equation derived from the first set of SLAE'"'"'s and second part of a second standard form equation derived from the second set of SLAE'"'"'s; and

forming a second product for a second one of the results in such a pair, the second product including a second part of the first one of the standard form equations derived from the first set of SLAE'"'"'s and a first part of the second one of the standard form equations derived from the second set of SLAE'"'"'s, and wherein the comparing of the pairs of results includes comparing respective ones of such first and second products.

11. The system of claim 10, wherein the equations of the SLAE'"'"'s are of a form:

e _i1 x ₁ +e _i2 x ₂ +e _i3 x ₃ + . . . +e _in x _n =b _i

wherein x_j are the unknowns, e_ij are the coefficients, and b_i are quantities, a first one of the standard form equations derived from the first set of SLAE'"'"'s is of the form;

(l_ii)_kx_i=(r_i)_k

with k=1, (l_ii)₁ forming the first part of the equation and (r_i)₁ forming the second part of the equation, and wherein a second one of the standard form equations derived from the second set of SLAE'"'"'s is of the form;

(l_ii)_kx_i=(r_i)_k

with k=2, (l_ii)₂ forming the first part of the equation and (r_i)₂ forming the second part of the equation.

12. The system of claim 11, wherein a first such product includes (l_ii)₁*(r_i)₂ and a second such product includes (l_ii)₂*(r_i)₁ and the comparing of respective pairs of results includes comparing the products (l_ii)₁*(r_i)₂ and (l_ii)₂*(r_i)₁.

13. A computer program product comprising a computer program on a computer readable storage medium having computer readable program code, the program code comprising:

first instructions for receiving, by a computer system, first information for a first representation of an electrical network, wherein the first representation includes a first set of simultaneous linear algebraic equations (SLAE'"'"'s);

second instructions for receiving, by the computer system, second information for a second representation of an electrical network, wherein the second representation includes a second set of SLAE'"'"'s and the computer system stores the first and second information on a computer readable medium, wherein the equations of the first and second sets of SLAE'"'"'s include a number of unknowns and have coefficients for the respective unknowns, a number of the coefficients being expressed in algebraic form, and wherein the coefficients of one such equation from one of the sets of SLAE'"'"'s are for respective elements of the set'"'"'s respective electrical network and the unknowns are for respective operating properties of the set'"'"'s respective electrical network;

third instructions for deriving, by the computer system, a certain pair of results for each unknown of each respective one of the SLAE'"'"'s and stored by the computer system on a computer readable medium, the results being derived from the respective sets of SLAE'"'"'s; and

fourth instructions for comparing, by the computer system, the pairs of results to determine a network equivalence, wherein the results derived from the SLAE'"'"'s are expressed in algebraic form so that the comparing of the pairs of results includes comparing algebraic expressions.

14. The computer program product of claim 13, wherein the first and second network representations are for respective first and second electrical networks and the network equivalence is for equivalence of the first and second electrical networks.

15. The computer program product of claim 13, wherein the first and second network representations are both for a same electrical network and the network equivalence is for equivalence of the first and second representations.

16. The computer program product of claim 13, wherein the deriving of such a pair of results for an unknown of the respective sets of SLAE'"'"'s includes:

forming a first product for a first one of the results in such a pair, the first product including a first part of a first standard form equation derived from the first set of SLAE'"'"'s and second part of a second standard form equation derived from the second set of SLAE'"'"'s; and

Is forming a second product for a second one of the results in such a pair, the second product including a second part of the first one of the standard form equations derived from the first set of SLAE'"'"'s and a first part of the second one of the standard form equations derived from the second set of SLAE'"'"'s, and wherein the comparing of the pairs of results includes comparing respective ones of such first and second products.

17. The computer program product of claim 16, wherein the equations of the SLAE'"'"'s are of a form:

e _i1 x ₁ +e _i2 x ₂ +e _i3 x ₃ + . . . +e _in x _n =b _i

wherein x_j are the unknowns, e_ij are the coefficients, and b_i are quantities, a first one of the standard form equations derived from the first set of SLAE'"'"'s is of the form;

(l_ii)_kx_i=(r_i)_k

with k=1, (l_ii)₁ forming the first part of the equation and (r_i)₁ forming the second part of the equation, and wherein a second one of the standard form equations derived from the second set of SLAE'"'"'s is of the form;

(l_ii)_kx_i=(r_i)_k

with k=2, (l_ii)₂ forming the first part of the equation and (r_i)₂ forming the second part of the equation.

18. The computer program product of claim 17, wherein a first such product includes (l_ii)₁*(r_i)₂ and a second such product includes (l_ii)₂*(r_i)₁ and the comparing of respective pairs of results includes comparing the products (l_ii)₁*(r_i)₂ and (l_ii)₂*(r_i)₁.