Yoichi Uemura

Analytical study on generator load rejection characteristic using advanced equivalent circuit

This paper describes the analytical study on generator load rejection characteristic using the advanced equivalent circuit model. The authors have studied the synchronous machine equivalent circuit model and transient phenomena, by simulation with the electromagnetic transients program (ATP-EMTP), and compared the results with the experimental data

Effects of field mutual leakage reactance in rotor circuit of synchronous generator on the transient and dynamic behavior

This paper describes the effects of field mutual leakage reactance in rotor circuit (Canay reactance) on analysis of generator transient and dynamic behavior. The authors derived a detailed equivalent circuit model for generator, and analyzed sudden short circuit out-of-phase synchronization load rejection and sudden load application phenomena of the generator by simulations using the electromagnetic transients program (ATP-EMTP). Then, they compared the obtained results with the experimental data to verify the validity of the proposed equivalent circuit. In addition to these analyses, the influence of field mutual leakage reactance on analysis of power system dynamic stability was investigated.

Effect of reactance saturation on transient and stability for cylindrical synchronous machine

This paper presents the influence of reactance saturation in transient and stability phenomena for cylindrical synchronous machine. For this purpose the authors have examined various equivalent circuit models using electromagnetic transients program (EMTP-ATP).

A study on quadrature equivalent circuit model in large synchronous machine

This paper describes a study on equivalent circuit model in a large synchronous machine. In this study, the authors studied the quadrature axis transient reactance xpsilaq, not only the influence of the operational impedance , but also the difference of transient and dynamic characteristics using finite element method (FEM) and EMTP.

Estimation of field mutual leakage reactance in synchronous machine by line-to-line sudden short circuit test

This paper describes the effect of field mutual leakage reactance in rotor circuit (Canay reactance) on analysis of small or medium capacity generator transient and dynamic behavior .The authors proposed the decision method of field mutual leakage reactance, and analyzed sudden short circuit and the power system dynamic stability characteristics affected by the rotor mutual leakage reactance

Study of saturation characteristic of equivalent circuits for cylindrical synchronous machine

The authors have studied the saturation characteristic of equivalent circuit of cylindrical synchronous machine. Using the measured data, the authors have studied the effect on the saturation characteristic of equivalent circuits by the finite element method (FEM) and the electromagnetic transients program (ATP-EMTP).

Effect of quadrature axis reactance of large cylindrical synchronous machine on operation

The authors have studied the effect of the quadrature axis transient reactance of large cylindrical synchronous machine on operation. Using the measured data, the authors studied the effect on the transient and stability phenomena by the finite element method (FEM) and the electromagnetic transients program (ATP-EMTP).

Calculation of transformer saturated leakage inductance based on field test data

In a black start of a power system, at times, an overvoltage could be caused by core saturation on the energization of a transformer with residual flux. Such an over-voltage might damage some equipment and delay power system restoration. Through an actual field test and EMTP simulations, we have found that such phenomena cannot be accurately simulated using a normal transformer model with inductance data measured during the factory test. This paper proposes a new calculation scheme of transformer inductance by using actual field test data in order to grasp the saturated transformer characteristics accurately. We also show an analytical scheme for calculating the leakage inductances from shunt currents in delta windings that give extensive influence to over-voltage under flux saturation

A study of synchronous machine modeling about synchronizing phenomena

This paper describes the study of synchronous machine modeling particularly with emphasizing on synchronizing phenomena. The authors proposed a graphical method to investigate the induced spiky voltage, examined the transient phenomena by the electromagnetic transient program (ATP-EMTP) and compared the results with the experimental data

Analytical study on synchronizing phenomena using generator model with field mutual leakage reactance

This work describes the effect of mutual leakage reactance in rotor circuit (Canay reactance) on analysis of generator transient characteristics. The authors derived a detailed equivalent circuit model for 48P-15750 kVA generator, and analyzed sodden short circuit and transient phenomena of the generator at synchronization by simulations using the electromagnetic transients program (ATP-EMTP).