## Search found 14 matches

- 2 months ago
- Forum: Modeling
- Topic: Coding second order cone constraint in GAMS
- Replies:
**3** - Views:
**190**

### Re: Coding second order cone constraint in GAMS

Thank you for your response sir. In fact I need to know how to write conic constraints in GAMS language. Like I mention in my case, let's assume V is a vector of variables which stands for the voltage magnitude squared of nodes. P and Q are also variable matrices stands for the active and reactive p...

- 2 months ago
- Forum: Modeling
- Topic: Coding second order cone constraint in GAMS
- Replies:
**3** - Views:
**190**

### Coding second order cone constraint in GAMS

Hi, I'm working on second order cone programming for power distribution system problems. Suppose my system includes 5 buses and 4 lines. So, set bi /bus1*bus5/ set li /line1*line4/ alias(bi,bj) Now the vector V(bi) stands for voltage magnitude squared of a node, P(bi,bj) and Q(bi,bj) stand for the a...

- 4 months ago
- Forum: Modeling
- Topic: Non linear constraint in a convex optimization.
- Replies:
**5** - Views:
**343**

### 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.

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.

- 4 months ago
- Forum: Modeling
- Topic: Non linear constraint in a convex optimization.
- Replies:
**5** - Views:
**343**

### 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'...

- 4 months ago
- Forum: Modeling
- Topic: Non linear constraint in a convex optimization.
- Replies:
**5** - Views:
**343**

### 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...

- 4 months ago
- Forum: Modeling
- Topic: Help regarding coding for a vector of interrelated elements.
- Replies:
**2** - Views:
**254**

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

Thank you so much sir.

- 4 months ago
- Forum: Modeling
- Topic: Help regarding coding for a vector of interrelated elements.
- Replies:
**2** - Views:
**254**

### 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...

- 8 months ago
- Forum: Modeling
- Topic: How to write a conic constraint in GAMS?
- Replies:
**1** - Views:
**334**

### 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.

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.

- 8 months ago
- Forum: Modeling
- Topic: GAMS for larger systems.
- Replies:
**5** - Views:
**453**

### Re: GAMS for larger systems.

Sir,

I've sent the codes to the mail address that you mentioned earlier.

Thank you.

I've sent the codes to the mail address that you mentioned earlier.

Thank you.

- 8 months ago
- Forum: Modeling
- Topic: Optimal Power Flow of larger power system.
- Replies:
**1** - Views:
**237**

### 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 ...