66results about How to "Solving Convergence Problems" patented technology

The invention provides a wind-resistant design method for a cable-membrane structure based on a loose coupling technology, which comprises the following steps of: 1, establishing a cable-membrane structure finite element model by a form-finding method according to the physical property of an actual material and the initial prestress of the structure; 2, establishing a cable-membrane structure fluid computation model according to a form-finding result in the step 1 and the ambient environment of a building; 3, taking a wind tunnel test or actually measured data or theoretical analog wind speedtime interval data as the inlet boundary condition of fluid computation; and 4, performing the wind-resistant design of the membrane structure by using a fluid-solid coupling cooperative platform. Bythe method, the problem of convergence in the conventional cable-membrane structure fluid-solid coupling computation is solved, and the computation speed is improved; and computation accuracy is obviously improved compared with that of the conventional simplified method and a unilateral coupling method, and the computation speed is high, so the technology is developed from scientific research to actual application.

The invention discloses a power flow calculation method for a small impedance branch-containing power network employing a compensation method and a fast decomposition method. Before power flow calculation, a small impedance branch is firstly processed and the small impedance branch is changed into a form of series connection of two branches, wherein the impedance of one branch is z1=r+j(x+xc), the impedance of the other branch is z2=-jxc, and xc is a mean value of reactance absolute values of the branches of which the reactance absolute values are smaller than a reactance threshold in a power system, and is called a normal reactance mean value of the power system. One small impedance branch is changed into two branches with relatively high impedance through series compensation, so that the convergence of power flow calculation can be improved. The small impedance branch with any impedance or even the branch with zero impedance can be calculated. According to the power flow calculation method, the problem of convergence due to the fact that a small impedance branch-containing branch system is analyzed by a conventional power flow calculation method employing the fast decomposition method can be effectively solved, and meanwhile, power flow calculation can be carried out on a normal system. Therefore, adverse effects are avoided.

The invention discloses a rapid decomposing method load flow calculating method suitable for a branch system comprising small impedance. The method comprises the step of inputting original data and initializing voltage, the step of forming a node admittance matrix, the step of forming a coefficient matrix B' and a coefficient matrix B'' of a modified equation and decomposing a factor table, the step of setting iteration count and a convergence mark, the step of calculating the inactive power unbalance amount delta Q, the step of judging whether the absolute value delta Qmax is smaller than the convergence accuracy epsilon or not, the step of calculating the active power unbalance amount delta P, the step of judging whether the absolute value delta Pmax is smaller than the convergence accuracy epsilon or not, the step of calculating the balance node power and the inactive power of a PV node, and the step of calculating the branch power. Part of elements in the coefficient matrix B' of the modified equation of a rapid decomposing method are modified, and the convergence problem produced during analyzing the branch system comprising the small impedance with the resistance not equal to zero in rapid decomposing load flow calculation is solved. When a convention method is adopted to calculate non-convergence, the rapid decomposing method load flow calculating method can carry out convergence reliably.

The invention discloses a method for imposing norms in the electromagnetic field edge element method, comprising: establishing a three-dimensional model of an object to be analyzed, and performing grid division on the three-dimensional model; calculating the magnetic vector of the edge unit after division The element matrix corresponding to the potential double-curl term, the Coulomb gauge term, and the current density term is integrated to form the overall finite element equation; the corresponding boundary conditions are applied to the overall finite element equation; the overall finite element equation with corresponding boundary conditions is applied Solve to obtain the only basic solution of the magnetic vector potential, and post-process the obtained basic solution of the magnetic vector potential to obtain the corresponding solution of the electromagnetic field. On the premise of ensuring accuracy, the present invention effectively solves the uniqueness problem of the magnetic vector potential in the edge element method; avoids the problem of complex spanning tree construction in the traditional method; at the same time, the efficiency is higher than that of the lager adopted in the edge element The method of imposing a Coulomb gauge by the Langerian multiplier method.