欢迎进入WEAP网站
WEAP
WEAP的首创和发起者 Stockholm Environment Institute.


关于WEAP

主页
为何选择WEAP?
WEAP模型简介
模型更新
屏幕举例
动画演示
模型应用
相关发表
模型发展及致谢

应用WEAP
下载
用户许可
用户指南
迅捷教程
视频资料
模型资源

用户论坛
发起讨论
会员列表
文本编辑

更多支持
模型训练
课堂讲授
广泛合作

关于我们
SEI-US 水资源论坛
联系我们

 环境新闻
LEAP 能源规划?
认识LEAP: SEI的能源规划软件

用户论坛

所有的话题 | 话题 "Constraints"
登录以发布新的消息或回复现有消息
 
作者 消息
Janak Timilsena

主题: Constraints   
公布: 12/14/2009 审阅的: 11072 times
I am working to set the constraints for the groundwater extraction. I am running the model in daily time step. In my project, constraint is in annual basis (i.e. it can not exceed 90 mgd for wateryear). Some of the time steps could be more than 90 mgd and some of the time step could be less than 90 mgd, but end of the water year the average should not be exceeded 90 mgd. I have tried to use the following function in max flow volume;

PrevTSValue(Maximum Flow Volume[Million gal],1,365,1<90)

but it constraints everytime step, which i donot want.

Do you have any suggestion to incorporate this type of constraint in WEAP?
Jack Sieber

主题: Re: Constraints   
公布: 12/14/2009 审阅的: 11071 times
Very interesting idea! What you are trying to do is constrain the flow through the transmission link in the current timestep so that it doesn't push the average (over the past year) above some threshold (90 million gallons per day (MGD)). In order to do this, you need to calculate the flow in the current timestep that would cause the average to be exactly 90 MGD, then constrain the flow through the link to be at most this flow. The answer is to subtract the total flow over the previous 364 days from 90 * 365 to get the "available" flow for the current day. Also, you need to make sure the answer is not negative.

Max(0, 365 * 90 - PrevTSValue(Flow[MGD], 1, 364) )

Note: PrevTSValue(Flow[MGD], 1, 364) will sum up the flow, in MGD, over the previous 364 days.

Jack

话题 "Constraints"