## Search found 12 matches

1 week ago
Forum: Modeling
Topic: Non linear constraint in a convex optimization.
Replies: 5
Views: 143

### Re: Non linear constraint in a convex optimization.

c(bi,bj) is also a parameter which denotes the connection between nodes. To re-write the equations as you said, variables as capital and parameters as small,

c(bi,bj)*(V(bi)-V(bj)) =e= c(bi,bj)*(2*(PL(bi,bj)*r(bi,bj) + QL(bi,bj)*x(bi,bj)) - (sqr(r(bi,bj))+sqr(x(bi,bj)))*IL(bi,bj));

Thank you.
1 week ago
Forum: Modeling
Topic: Non linear constraint in a convex optimization.
Replies: 5
Views: 143

### Re: Non linear constraint in a convex optimization.

Thank you sir for your reply. But I defined the squared of voltage magnitude V_i^2 with a new variable v(bi) and current squared with il(bi,bj). So, in the equation c(bi,bj)*(v(bi)-v(bj)) =e= c(bi,bj)*(2*(pl(bi,bj)*R(bi,bj) + ql(bi,bj)*X(bi,bj)) - (sqr(R(bi,bj))+sqr(X(bi,bj)))*il(bi,bj)); there isn'...
2 weeks ago
Forum: Modeling
Topic: Non linear constraint in a convex optimization.
Replies: 5
Views: 143

### Non linear constraint in a convex optimization.

Hello, I am intending to formulate a convex optimization for a distribution system containing size of 13 bus of example. The variables are as such, set: bi=bj=/bus1*bus13/; voltage squared: v(bi) line current: il(bi,bj) line active power: pl(bi,bj) line reactive power: ql(bi,bj) line resistance: R(b...
1 month ago
Forum: Modeling
Topic: Help regarding coding for a vector of interrelated elements.
Replies: 2
Views: 140

### Re: Help regarding coding for a vector of interrelated elements.

Thank you so much sir.
1 month ago
Forum: Modeling
Topic: Help regarding coding for a vector of interrelated elements.
Replies: 2
Views: 140

### Help regarding coding for a vector of interrelated elements.

Hello, Let's say I want to to write the following code in GAMS, V, %vector of size 10 diff, %vector of size 10 for i=2:10 V(i)=V(i-1) + diff(i); end How do I write similar code in GAMS? Let's assume I have a variable V of size b, where b=/x1,x2,x3,x4/, similarly the diff variable has same index b. T...
4 months ago
Forum: Modeling
Topic: How to write a conic constraint in GAMS?
Replies: 1
Views: 240

### How to write a conic constraint in GAMS?

Hello,
I need to add a conic constraint in my model. For example, the constraint is ||2A, 2B, C-D||<= C+D. The order of the conic is 2. How to write that in the GAMS language?
Thank you.
5 months ago
Forum: Modeling
Topic: GAMS for larger systems.
Replies: 5
Views: 314

### Re: GAMS for larger systems.

Sir,
I've sent the codes to the mail address that you mentioned earlier.
Thank you.
5 months ago
Forum: Modeling
Topic: Optimal Power Flow of larger power system.
Replies: 1
Views: 152

### Optimal Power Flow of larger power system.

Hi, Did anyone works on optimal power flow of larger systems? Currently I'm working with a 500 nodes system which consists of 599 lines and 90 generators. I'm using Quadratic Constrained Programming to solve. But, while building the model, every time GAMS ran out of memory after occupying more that ...
5 months ago
Forum: Modeling
Topic: GAMS for larger systems.
Replies: 5
Views: 314

### Re: GAMS for larger systems.

And sir, here are the lines from .lst file where mentioned about the memory allocation issues: *** Out of Memory while executing line 4321 Heap Statistics for heap: BBMgr Memory in use = 27,047 Mb Highest memory used = 27,047 Mb Large blocks available = 0 Statistics for small heap: gheap Nr Allocate...
5 months ago
Forum: Modeling
Topic: GAMS for larger systems.
Replies: 5
Views: 314

### Re: GAMS for larger systems.

Thank you for your reply sir. Here's the log that you asked for: --- Starting compilation --- trial_1.gms(64) 3 Mb --- .ReYbus_mat.csv(501) 3 Mb --- trial_1.gms(70) 3 Mb --- .ImYbus_mat.csv(501) 3 Mb --- trial_1.gms(76) 3 Mb --- .ReYf_mat.csv(600) 3 Mb --- trial_1.gms(82) 3 Mb --- .ImYf_mat.csv(600)...