Chen Baichao

Electrical Railway Active Power Filter Research Based on Genetic Algorithms

In order to realize real-time examination and compensation to the electrical railroad harmonic and reactive power, this article proposes an optimum control rule of the switch component in the active power filter based on genetic algorithm. The detected load current is calculated and the instruction current is obtained through digital signal processor (DSP) circuit and analog to digital converter (ADC). According to the relations between actual compensation current and instruction current, the goal optimization function is established in the inverter switch control strategy. Through drive circuit the pulse width modulation (PWM) which outputted by DSP controls insulated-gate bipolar transistor (IGBT) in converter, the compensation current real-timely is tracked the change of its instruction current. After being simulated by simulating platform provided by MATLAB, it shows that it has tangible effect on electrical railroad harmonic compensation which based on the genetic algorithm active power filter. This will not only will enhance the reliability of electric railway traction transformer station but also play an important role in the operating security of electric network.

The Research of Inverter's Control based on Immune Genetic Algorithm

This paper evaluates immune genetic algorithms (IGA) as a new nonlinear technique for control of inverter. The so-called IGA strategy is characterized by its speediness, diversity, tolerance and memory. It is well suited for online microprocessor implementation. A special C program for the algorithm is compiled. And the dynamic experimental platform based on DSP was built. Simulation and experiment results show that the algorithm quickly converged to the good solution within 25th iterations, and the solutions fitness and switching loss are great improved compared with the traditional control strategies

A Novel Neutral Electromagnetic Hybrid Flexible Grounding Method in Distribution Networks

This paper proposes a flexible neutral grounding method based on electromagnetic hybrid Petersen coil (EHPC), which consists of a magnetically controlled reactor and an active power compensator (APC). Under normal conditions, the systems neutral point grounds through a reactor of high reactance. When a single line-to-earth fault occurs, the EHPC can be controlled flexibly to suppress the recovery voltage of faulty phase and to reduce the ground-fault current to almost zero. This paper expounds the two operating modes and corresponding characteristics, the measuring method of insulation parameters of the system (mainly including capacitance to earth and leakage resistance), and the full compensation principle for arc suppression based on the equivalent negative impedance of EHPC. This paper also proposes a compound control method of neutral-to-earth impedance based on neutral-point displacement voltage and a compensating method for the harmonic component of the ground-fault current. Compared to traditional grounding methods, this method can be fast and reliably make the residual current approach almost zero without arc reignition while greatly reducing the output capacity of APC and, thus, decreasing the cost of this device. Simulations and experiments verify the correctness of this measuring method and feasibility of this flexible grounding control strategy.

Inverter Control Research Based on Immune Algorithms

In this paper a new control law of inverters based on immune algorithms is presented. In the control law multi-objective function is created, which enables a voltage-source type inverter to produce a near standard sine wave with a minimum switching loss. Because the control law is based on float-coded immune algorithms (IA), the method overcomes the disadvantages of binary-coded genetic algorithm (GA), effectively adopts float-coded manner to make the work simple and quick and improves the speed and precision of the algorithm. Through computer simulation the result has proven that the immune algorithms are effective to the inverter control.

Research on TCSC control strategy to improve the EHV and UHV power grid stability

A TCSC (thyristor controlled series compensator) model based on the Current Injection Method is present, and an adaptive fuzzy logic TCSC controller is designed. With the Genetic Algorithm the parameters of TCSC can be adjusted robustly by the adaptive fuzz rules. Simulation results according to the different run modes on typical 500 kV line are presented to demonstrate the control strategy based on the energy function method can improve the stability of the EHV power grid. The TCSC model based on the Current Injection Method is feasible in the EHV power grid and significant to the development of UHV power grid.

Study on a New Injecting Hybrid Active Power Filter

According to commonly used hybrid avtive power filter, the injecting active power filter is introduced to reduce the capacidance as much as possible without taking first -harmonic voltage. This paper illustrates the working principle of hybrid and injecting active power filter and proves with experiment.