On‐line Detection of Harmonics Components in Magnet Defect Fault of Permanent Magnet Synchronous Motor through a Modified Prony's Method

The use of permanent magnets in the structure of electric machines, in addition to simplifying design and construction by reducing losses, leads to increased efficiency in the motor. However, the magnetic material can be damaged by failure caused by faults such as short circuits in the electronic driver of the motor. Magnets containing samarium and neodymium are completely brittle and easy to crack. These elements are also very vulnerable due to their crystalline structure and grain texture. Magnet defect fault is one of the most common faults in permanent magnet machines. In this paper, a permanent magnet synchronous motor (PMSM) with a magnet defect fault is simulated using the finite element method. Moreover, Prony's method is modified by the matrix pencil method for the estimation of the component created in the stator current. The frequency spectrum of magnetic flux density and stator current in both faulty and healthy modes are extracted and fault detection is done through a modified Prony's method

Smart distribution network operation based on energy management system considering economic-technical goals of network operator

This paper expresses economic flexible–securable operation (EFSO) in smart distribution networks (SDNs), including distributed generation and storage systems to produce green energy. This is structured as an optimization formulation to obtain a minimum expected operation cost, constrained by optimal power flow, environmental, security, and flexibility limits. Also, mathematical expressions of power sources and storage are presented. The scheme considers uncertainties related to load, price of energy, and generation power of renewable sources. The work adopts the point estimation method (PEM)-based stochastic optimization to model the uncertainties. It also uses to evaluate the flexibility index accurately while requiring short computation time (among the objectives of power system operation). Then, the results demonstrate its capabilities in enhancing various aspects of the network, including economic, environmental, operational, security, and flexibility indicators. The design helps derive flexibility conditions of almost 100%. It improves the operating cost, energy loss, voltage deviation, amount of pollution emission, and voltage security index by approximately 23%, 29%, 47%, 51%, and 13% compared with power flow studies

Presenting a Stochastic Model of Simultaneous Planning Problem of Distribution and Subtransmission Network Development considering the Reliability and Security Indicators

Consumption growth demands power system expansion, and changes in a network lead to changes in operation indices of the upstream network. Hence, to establish a reliable planning of the distribution network, simultaneous planning of the subtransmission network should also be taken into account. It is predicted that this planning impacts different technical indices; therefore, formulation of various technical indices need to be included in the planning model. Therefore, in this study, the stochastic problem model of simultaneous planning of distribution and super distribution network development considering the reliability and security indicators is presented. The aforementioned problem is in the form of an optimization problem whose objective function is to minimize the costs of construction, replacement, operation, maintenance, reliability, and security. Furthermore, the mentioned problem is bound to the equations of power distribution, reliability, and security of voltage in addition to the limitation of network indicators. It is worth mentioning that, in the proposed problem, the active and reactive loads in addition to the operating price are in the form of uncertainty. Thus, the mentioned problem is in the form of a stochastic problem in which the point estimation method is used to evaluate the scenarios. Simultaneous expansion planning of distribution and subtransmission networks along with the placement of distributed generations and capacitors, as well as modeling security and reliability indices, is the novelty of the proposed scheme. In the end, the proposed problem is applied to the test network by GAMS optimization software, and then the capabilities of the proposed problem are extracted. Accordingly, based on numerical results, the expansion of distribution networks imposes considerable cost. Moreover, expansion planning of both distribution and subtransmission networks helps voltage to be in its permissible range, lower power loss, and improve reliability and security to 100%