This paper presents a comprehensive analysis about bus bar design procedure. Some applications in terms of rated power and shape are investigated regarding their particular requirements and challenges. The dc-link capacitor selection is one of the first and most important steps. It not only dictates the bus bar complexity but also is the key to accomplish a high-power density prototype. Current density and distribution is discussed in this paper based on simulation results. Moreover, the effects of stray inductance and capacitance are explained along with the dc-link capacitors and power semiconductor devices. Simulated results are compared with measurements by a high precision impedance analyzer, which shows the reliability of 3-D modeling-based designs.

Bus Bar Design for High-Power Inverters

A wind energy conversion system with maximum power tracking using a switched reluctance generator is presented in this paper. Maximum power point tracking of the wind turbine is achieved by sensing the wind speed and adjusting the wind turbine shaft speed for optimal tip speed ratio. Outer speed loop with proportional-integral controller generates the current reference used by the inner current loop. Hysteresis current control using soft-chopping is used to control the switched reluctance generator phase currents. Initial excitation is provided by a low voltage battery and rated voltage is built-up by self-excitation. A chopper controlled dump resistor is used to maintain the output dc voltage at rated value. The system is modeled and simulated in MATLAB-SIMULINK and satisfactory results are obtained.

Control of switched reluctance generator in wind energy system

In this paper, the structure of switched reluctance generator wind power system is introduced. Then compared with the existing maximum power point tracking method, a speed disturbance variable step hill-climbing search method is given. And the implementation process of maximum power point tracking is analyzed in detail. Afterwards, a strategy of the maximum power point tracking and voltage closed-loop control is proposed in order to maximize the utilization of wind energy and ensure the power quality of the users. In the end, the proposed strategy is tested with the three-phase 12/8 structure switched reluctance generator and the semi-physical simulator RT-LAB control in hardware and software. It is shown that the proposed strategy has good control performance.

Switched reluctance generator control for wind power system

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/pel2.12008

A safe commutation strategy based on LRCD snubber circuit for five-level active neutral point clamped inverter

The invention discloses a maximum power tracking control method for a variable-speed switched reluctance wind generator. An excitation turn-on angle in an excitation phase is always fixed; any switching tube control mode of chopping or PWM is not adopted; testing is carried out before operation according to different rotating speeds: an excitation turn-off angle and excitation voltage corresponding to maximum output power are recorded in an interval below a rated rotating speed, and the excitation turn-off angle and the excitation voltage corresponding to rated output power are recorded in aninterval above the rated rotating speed, thereby correspondingly compiling the excitation turn-off angles and the excitation voltage at various rotating speeds into a query table; and the excitation turn-off angles and the excitation voltage are queried according to the actual rotating speed as tracking control signals during system operation. The method is simple, feasible and low in loss, and isof practical significance to application of the switched reluctance generator in variable-speed wind power.

Maximum power tracking control method for variable-speed switched reluctance wind generator

In this paper, a switched reluctance generator (SRG) system is established for wind power generation. The designed system includes: an asymmetric half-bridge power convertor, a 12/8 three-phase SRG and control circuits which is dominated by digital controller dsPIC30F6010A. With optimized control parameters, the system achieve good dynamic and static performance with power feedback control. Then, the behavior of wind turbine is studied. For further adoption on wind power generation, a novel maximum power point tracking (MPPT) method basing on the wind turbine output behavior curve is proposed. In the proposed MPPT strategy, the outer loop controls rotor speed, while inner loop adopts PI controller for power feedback control. In the end, with optimized control parameters, the system shows good performance on a 48V experimental platform.

http://ieeexplore.ieee.org/iel7/7091673/7102217/07102286.pdf

Design of switched reluctance generator system for wind power maximization

This paper presents a power convertor design of a 60kW three-phase asymmetry half-bridge power convertor for switched reluctance machines (SRM). With established topology, voltage overshoot is sufficiently analyzed theoretically. To minimize voltage overshoot, this paper optimized the structure of main circuits, snubber capacitors and drive circuits. When dealing with main circuits structure, a low inductance busbar design with optimal capacitors arrangement is proposed for stray inductance minimization. For drive circuits, active clamp circuits are adopted to limit current reduction. Take minimized stray inductance and active clamped circuits into consideration, mathematic model between snubber capacitors and voltage overshoot is proposed for optimization. In the end, feasibility and improved performance are demonstrated with simulation and experiments.

http://ieeexplore.ieee.org/iel7/7091673/7102217/07102287.pdf

Development of a compact 60kW three-phase asymmetry half-bridge power convertor with specifically designed busbar for switched reluctance machines

Resistive current live test plays an important role in the technical supervision of metal oxide arrester (MOA). At the same time, there are some conditions that MOA can not find hidden dangers and defects through AC leakage current live test. This paper puts forward an assumption: the AC leakage current live test technology under operating voltage has different fault detection effects on different insulating parts of MOA. It is found that in the overall AC leakage current composition of the arrester, the resistance sheet and porcelain jacket account for a large proportion, and the proportion of FRP core insulating support rod and epoxy resin insulating cylinder is very small, so the AC leakage current test under operating voltage can effectively detect the faults on the resistance sheet and porcelain jacket, and it is difficult to detect the insulating support rod Fault on insulating cylinder (or insulating package). This study clears a blind spot of the safe operation of the arrester, provides a reference for the condition based maintenance of the arrester, and improves the operation and maintenance level of the arrester. 

Study on the difference of fault detection effect of AC leakage current live test technology under operating voltage on different insulating parts of MOA

Renming Zhao

Papers

Design of switched reluctance generator system for wind power maximization

Development of a compact 60kW three-phase asymmetry half-bridge power convertor with specifically designed busbar for switched reluctance machines

Study on the difference of fault detection effect of AC leakage current live test technology under operating voltage on different insulating parts of MOA