Yin Zhongdong

Design of Simulation Model of PV Cells Based on VSR PWM Rectifier Circuit

This paper designs the simulation model of the PV (photovoltaic) cells by using the mathematical model applying in engineering firstly. Then the output of the PV cells is simulated based on the PSCAD/EMTDC platform by using the single-phase VSR PWM rectifier circuit which uses the direct current control as well with the triangular wave current comparison as the control strategy. The results show that the model could simulate the output of the PV cells well and could also meet the V-I characteristics of the loads. This model will have good practicability for the further design of MPPT algorithm applying in the photovoltaic grid-connected system too.

Research on the magnetic valve thyristor controlled reactor

The magnetic valve thyristor controlled reactor (MVTCR) is presented and its configuration and working principle are described in this paper. It is set up for the mathematical models based on equivalent electrical circuit and magnetic circuit by using an analytical method to calculate steady-state characteristics. The characteristics of the reactor are shown by numerical simulations. Some interesting features of MVTCR are revealed in the paper. As an example, model tests of a prototype of 1 kVA, 0.4 kV reactor are performed to support the theoretical results.

Influence of Coordinate Controllable Neutral Reactors on UHV Secondary Arc Current

In order to ensure the succeed of auto-reclosing, it is common to adopt shunt reactor and neutral reactors to suppress secondary arc on the head and end of Ultra High Voltage (UHV) transmission lines. However, uncontrollable reactor widely used in practical engineering could not reach the best result of suppressing secondary arc. In this paper, the influence of shunt reactor and neutral reactors under coordinate control is discussed. The quadric-mode transformation is adopted to establish the mathematic model of secondary arc current in the double-circuit transmission line. According to the variation of neutral reactors, the secondary arc current of different fault points is calculated. The results indicate that neutral reactors have a great influence on secondary arc current of different fault point, and the method of coordinate controllable neutral reactors should be taken to suppress secondary arc current.

Research on voltage regulation of magnetic valve controlled reactor based on thyristor

The magnetic valve controlled reactor and its automatic voltage regulation apparatus are introduced in the paper. First, its special configuration, working principle and characteristics are presented. The feature of the controlling system is analyzed. Finally, the results of the voltage regulating model test are given.

A Direct Current Control of Shunt Active Power Filter

This paper presents a direct current control strategy of shunt active power filter system (SAPF) to eliminate harmonics generated by the nonlinear load. The SAPF system is realized using a three-phase voltage source inverter(VSI) with self-supported dc bus. The compensation principles and dynamics of the system are discussed in detail. The proportional- integral (PI) control strategy is adopted to maintain the dc bus voltage of the SAPF stable. The modeling equations of the SAPF are derived for compensation of harmonics generated by a three-phase rectifier load. Finally, simulations are carried on the platform of PSCAD/EMTDC. The results show that the proposed control strategy is feasible and efficient.

A Novel Voltage Balance Control Strategy of AC-DC-AC Converter

A general problem in the double PWM converter is the voltage unbalance of the dc-link capacitors. This unbalance distorts the waveforms of the output voltage and current. Furthermore, it will lead to instability of the inverter system. Based on the analysis for the unbalance problem, a novel feedback control strategy of DC capacitor voltage deviation is proposed in this paper. The method does not add extra circuit. Build an simulation model of AC-DC-AC converter, the results show that control strategy is correct.

The VSCF generator interconnection under Stator-flux-oriented vector control

With the increase in the energy problems, new energy resources, such as wind power, are seriously focused on. The interconnection technology of double-fed induction generator (DFIG), which is used in wind power generation, has turned into an important part. The stator-flux-oriented vector control principle is applied to build a model of the typical DFIG in dq synchronous revolution coordinate system, and the PSCAD/EMTDC simulation software is employed to research the interconnection control method, furthermore, the double loops control strategy is adopted. The application of the separating integral PI control can eliminate the system oscillation and can smooth the start course. The simulation results show that the stator-flux-oriented vector control is an effective method that aims at the interconnection of the DFIG.