R/create_voltage_constraints_parallel_branch.R

In asiono/rein: Distribution Grid Reinforcement Optimization

################################################################################
#' @title    create_voltage_constraints_parallel_branch
#' @description  creates the constraints given by the voltage over the newly added parallel lines
#' @param solution_space  dataframe containing possible cable and transformer types in the grid and its specifications
#' @param big_M  big M value for voltage limit optimization
#' @param allowed_voltage  allowed voltage deviatipn limit
#' @param verbose  Value greater than zero to display step by step of reinforcement.
#' @return This function creates the side conditions and objective function for the optimization problem. 
#' The ouput is a list. That contains A, b and c. 
################################################################################

create_voltage_constraints_parallel_branch <- function(solution_space, big_M, allowed_voltage, verbose = 0){
  #todo this function won't work without parallel_lines or with a single parallel line 
  #problems will occur when a dataframe is expected but only a vector is available

  parallel_lines_places <- (grepl('Parallel_', colnames(solution_space$A))
                            & !grepl('I_b_', colnames(solution_space$A)))
  
  # paths starting after a parallel line 
  orgininal_paths <- solution_space$A[, grep('Path', colnames(solution_space$A))]
  parallel_to_lines <- solution_space$A[, parallel_lines_places, drop = FALSE]
  
  # find the endings of the parallel lines 
  # this is done by subtracting the elements that are parallel to the other path
  
  parallel_endings_storage <- NULL
  for (i in 1:ncol(orgininal_paths)) {
    parallel_endings  <- orgininal_paths[,i] - parallel_to_lines
    common_path       <- parallel_endings != -1 
    common_path       <- apply(common_path, 2, all)
    if (!any(common_path)) next
    if (is.null(parallel_endings_storage)) {
      parallel_endings_storage <- data.frame(parallel_endings[, common_path]) 
      colnames(parallel_endings_storage) = colnames(parallel_endings)[common_path]
    }else{
      cln = colnames(parallel_endings_storage)
      parallel_endings_storage <- cbind(parallel_endings_storage,parallel_endings[, common_path])
      colnames(parallel_endings_storage) =  c(cln, colnames(parallel_endings)[common_path])
    }
    
    #parallel_to_lines <- parallel_to_lines[, !common_path]
  }

  #browser()
  A1_1 <- t(parallel_endings_storage*solution_space$A$dU)
  d_U_temp <- solution_space$P$dU + big_M
  A1_2 <- t(solution_space$P[,colnames(parallel_endings_storage)]*d_U_temp)  
  A1 <- cbind(A1_1, A1_2)  
  
  rownames(A1)[] <- 'parallel_line'
  b1 <- rep(allowed_voltage,nrow(A1)) + big_M
  const.dir <- rep('<=', nrow(A1))
  
  
  ## add new rows for voltage swing under zero
  A <- matrix( rep( t(A1) , 2 ) , ncol = ncol(A1) , byrow = TRUE)
  b2 <- rep(allowed_voltage*-1, nrow(A1)) - big_M
  const.dir <- c(const.dir, rep('>=', nrow(A1)))
  
  rownames(A)[] <- 'parallel_line'
  
  matrices <- list(A = A, b1 = b1, b2 = b2, const.dir = const.dir)
  
  return(matrices)
}