My guess is that the OPF is not converging due to unreasonable voltage set
points (your code generates voltage values ranging from less than 1e-4 to
greater than 5 p.u. Make sure you check the value of r.success to check if the
OPF converges and use reasonable voltages (e.g 0.95 < V < 1.05). Also, are you
sure you want to use an identical voltage at all of the buses? That doesn't
seem like a reasonable requirement.
--
Ray Zimmerman
Senior Research Associate
419A Warren Hall, Cornell University, Ithaca, NY 14853
phone: (607) 255-9645
On Mar 26, 2012, at 11:47 AM, Silvio Miceli wrote:
> My mean is this:
>
> For the following code the results are always the same. Why I have to get the
> same results by changing voltage limits
>
> define_constants;
> mpc = loadcase('case9');
> for k = 1:5
> m=abs((normrnd(1,1,8760,1)));
> V = m(1); % generate a random draw of voltages
> mpc.bus(1:6, VMIN) = V;
> mpc.bus(1:6, VMAX) = V;
> r = runopf(mpc);
>
> end
>
>
> Best Wishes
>
> Silvio Miceli
>
>
> On Mon, Mar 26, 2012 at 17:25, Ray Zimmerman <[email protected]> wrote:
> Sorry, you are going to have to describe what you are doing in a bit more
> detail and ask your question more clearly. Different results between what and
> what for the OPF? Same results between what and what for runmarket? What is
> the reason for what?
>
> --
> Ray Zimmerman
> Senior Research Associate
> 419A Warren Hall, Cornell University, Ithaca, NY 14853
> phone: (607) 255-9645
>
>
>
>
> On Mar 26, 2012, at 11:20 AM, Silvio Miceli wrote:
>
>> Dear Ray,
>>
>> When I do an OPF with variable voltages I get different results while for
>> the runmarket I get the same results. runmarket is done underlying an OPF.
>> What is the reason?
>>
>> Best Wishes
>>
>> Silvio Miceli
>>
>>
>> On Sun, Mar 25, 2012 at 03:28, Silvio Miceli <[email protected]> wrote:
>> Dear Prof. Zimmerman,
>>
>> Thank you very much.
>>
>> Best Wishes
>>
>> Silvio Miceli
>>
>>
>>
>> On Sat, Mar 24, 2012 at 01:44, Ray Zimmerman <[email protected]> wrote:
>> As I mentioned before, in MATPOWER's OPF the voltages *are* optimization
>> variables. In other words, they are *output* values that depend on all of
>> the input parameters. If you want to treat the voltages at generator buses
>> as inputs (that you can set randomly according to some distribution), then
>> you will need to set the VMIN and VMAX values at that corresponding bus to
>> the desired value before calling the OPF.
>>
>> Something like this, where randomvoltage() is a function that returns a
>> voltage for each generator bus drawn from some specified distribution and ig
>> is the vector of indexes of generator buses ...
>>
>> mpc = loadcase('mybasecase');
>> for k = 1:10000
>> V = randomvoltage(); % generate a random draw of voltages
>> mpc.bus(ig, VMIN) = V;
>> mpc.bus(ig, VMAX) = V;
>> r = runopf(mpc);
>> % save whatever outputs you want to collect
>> end
>>
>> --
>> Ray Zimmerman
>> Senior Research Associate
>> 419A Warren Hall, Cornell University, Ithaca, NY 14853
>> phone: (607) 255-9645
>>
>>
>>
>>
>> On Mar 23, 2012, at 7:13 PM, Silvio Miceli wrote:
>>
>>> Dear Johnny
>>>
>>> I want to do a probabilistic OPF by using Monte Carlo. So, I have to load a
>>> distribution of voltage at the buses. I think MATPOWER is not able to load
>>> variables as optimization variable. If you have an idea please let me know.
>>>
>>> Best Wishes
>>>
>>> Silvio Miceli
>>>
>>>
>>> On Fri, Mar 23, 2012 at 23:39, Johnny <[email protected]> wrote:
>>> Silvio Miceli <[email protected]> writes:
>>>
>>> > Dear Shiyang,
>>> >
>>> > I also want to do it by Monte Carlo, but not loads. I want to have a
>>> > distribution of voltage as input. When I load loadcase it gives error. My
>>> > mean
>>> > is this:
>>> > I want load variable voltage values in bus matrix. Is it possible?
>>> >
>>>
>>> Silvio,
>>>
>>> I believe the best way to achieve this is to generate the normal
>>> distibution in a script which calls the OPF solver and collect the
>>> results to display as a distribution. So, in the Monte Carlo, you use
>>> stochastic input on a Black Box model and collect stochastic
>>> output. This normally takes some time, but what do you look for really?
>>>
>>>
>>>
>>> > Best Wishes
>>> >
>>> > Silvio Miceli
>>> >
>>> > On Fri, Mar 23, 2012 at 23:19, 李诗旸 <[email protected]> wrote:
>>> >
>>> > HI Silvio Miceli,
>>> >
>>> > I think Mr. Zimmerman’s suggestion is the way like Monte Carlo Method.
>>> > Normally, you may have the distributions of some parameters (inputs)
>>> > such
>>> > as loads and active generations, then you could use that way to get
>>> > the
>>> > distributions of the optimized voltages (output) numerically.
>>> >
>>> >
>>> >
>>> > Sincerely
>>> >
>>> > Shiyang Li
>>> >
>>> >
>>> >
>>> > 发件人: [email protected] [mailto:
>>> > [email protected]] 代表 Silvio Miceli
>>> > 发送时间: 2012年3月24日 4:31
>>> > 收件人: MATPOWER discussion forum; Ray Zimmerman
>>> > 主题: Re: probabilistic voltage
>>> >
>>> >
>>> >
>>> > I want to a have a distribution of voltage at buses that it is an
>>> > optimization variable in MATPOWER? These distributions are the inputs
>>> > for
>>> > the OPF.
>>> >
>>> > Best Wishes
>>> >
>>> >
>>> >
>>> > Silvio Miceli
>>> >
>>> > On Fri, Mar 23, 2012 at 21:25, Ray Zimmerman <[email protected]> wrote:
>>> >
>>> > I'm afraid I don't know what *you* mean. The voltages are *outputs* of
>>> > MATPOWER's OPF. So what are the input parameters that you would like
>>> > to be
>>> > stochastic? Voltage limits?
>>> >
>>> >
>>> >
>>> > --
>>> >
>>> > Ray Zimmerman
>>> >
>>> > Senior Research Associate
>>> >
>>> > 419A Warren Hall, Cornell University, Ithaca, NY 14853
>>> >
>>> > phone: (607) 255-9645
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> > On Mar 23, 2012, at 2:40 PM, Silvio Miceli wrote:
>>> >
>>> > My problem is this I cannot do loadcase. How can I do many, many
>>> > deterministic optimization? If I introduce voltage as x and do it
>>> > with a
>>> > FOR?
>>> >
>>> >
>>> >
>>> > Could you please explain better? I didn't understand. I am sorry.
>>> >
>>> > Best Wishes
>>> >
>>> >
>>> >
>>> > Silvio Miceli
>>> >
>>> > On Fri, Mar 23, 2012 at 19:22, Ray Zimmerman <[email protected]> wrote:
>>> >
>>> > MATPOWER does not implement any stochastic optimization. All of it's
>>> > variables and parameters are assumed to be deterministic. However, one
>>> > approach to handling probabilistic parameters is to simply do many,
>>> > many
>>> > deterministic optimizations, where each one involves, for each
>>> > probabilistic parameter, drawing a value from the corresponding
>>> > distribution. Such an approach could use MATPOWER's OPF as a
>>> > subroutine to
>>> > solve the deterministic sub-problem.
>>> >
>>> >
>>> >
>>> > --
>>> >
>>> > Ray Zimmerman
>>> >
>>> > Senior Research Associate
>>> >
>>> > 419A Warren Hall, Cornell University, Ithaca, NY 14853
>>> >
>>> > phone: (607) 255-9645
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> > On Mar 23, 2012, at 12:42 PM, Silvio Miceli wrote:
>>> >
>>> > Dear Dr. Zimmerman,
>>> >
>>> >
>>> >
>>> > I want to have probabilistic voltage or reactive power in an OPF. In
>>> > other
>>> > words, I want to do OPF with probabilistic variables,e.g. voltage
>>> > should be
>>> > a normal distribution of voltage. How can insert this kind of
>>> > variables to
>>> > case file of MATPOWER? Is there this possibility in MATPOWER?
>>> >
>>> >
>>> >
>>> > Best Wishes
>>> >
>>> >
>>> >
>>> > Silvio Miceli
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>>
>>> --
>>> Johnny
>>>
>>>
>>>
>>
>>
>>
>
>
