National Key Laboratory for Vessel Integrated Power System Technology

Wuhan, China

National Key Laboratory for Vessel Integrated Power System Technology

Wuhan, China
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Cai X.,Huazhong University of Science and Technology | Cai X.,Fujian University of Technology | Cai X.,National Key Laboratory for Vessel Integrated Power System Technology | Wu Z.,National Key Laboratory for Vessel Integrated Power System Technology | And 2 more authors.
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | Year: 2016

In practice, many factors result in non-equal cell DC voltages of the cascaded H-bridge multilevel (CHBML) inverter, such as the differences amongthe DC sources of the H-bridge cells and the faults of the DC sources. The classical phase-shifted carrier (PSC) pulse width modulation (PWM) is unable to eliminate the low-frequency sideband-harmonics when the DC voltages of the cells are not equal. The quality of the output voltage degrades. In this paper, the relationship among the cell carrier-phases, the DC voltages, and the harmonics of the output voltage are analyzed. And then, a novel PSCPWM method, in which the carrier phases are regulated according to the different DC voltages, is proposed. This method improves the quality of the output power by eliminating the low-frequency sideband harmonics, and also enhances the fault-tolerance capability of the inverters. The simulation and experimental results obtained from the prototype of the CHBML inverter verify the suggested regulation strategy. © 2016, The editorial office of Transaction of China Electrotechnical Society. All right reserved.


Wang G.,National Key Laboratory for Vessel Integrated Power System Technology | Ma F.,National Key Laboratory for Vessel Integrated Power System Technology | Fu L.,National Key Laboratory for Vessel Integrated Power System Technology | Shi Q.,Xi'an Jiaotong University | Chen Y.,National Key Laboratory for Vessel Integrated Power System Technology
2014 17th International Conference on Electrical Machines and Systems, ICEMS 2014 | Year: 2015

This paper derives mathematics model of 6-pulse diode rectifiers. Its periodic orbit model and Poincaré mapping are established and its steady state performance index and stability margin index can be calculated by the model. dc bus voltage sag can be assessed by the periodic orbit model and the mathematics model. The model is validated by comparison of the resultant steady state and dynamic state behaviors with those obtained from extensive simulations of detailed 6-pulse diode rectifiers model. It is shown that the model can capture the key features of the dynamic response of the rectifiers and dc bus voltage sag, which can be used for performance assessment of dc power systems with the diode rectifiers. © 2014 IEEE.


Cai X.,Huazhong University of Science and Technology | Cai X.,Fujian University of Technology | Wu Z.,National Key Laboratory for Vessel Integrated Power System Technology | Sun L.,Xi'an Jiaotong University
2014 17th International Conference on Electrical Machines and Systems, ICEMS 2014 | Year: 2015

Since many Cascaded H-bridge multilevel (CHBML) inverters that are applied to drive high voltage machines can't transmit electric energy reversely, the electric energy transmitted from the machines may damage the inverters. This paper presents a transfer function to analyze the electromagnetic torque, when the load torque changes suddenly. Based on the achievements, the electric energy that flows between the machine and the inverter can be calculated. And then, a method is proposed to prevent the reversion of the direction of energy flow. Furthermore, the transfer function can be used to guide the design of the control system of induction machine. Simulation results verify the transfer function and the presented method. © 2014 IEEE.


Wang G.,National Key Laboratory for Vessel Integrated Power System Technology | Ji F.,National Key Laboratory for Vessel Integrated Power System Technology | Fu L.,National Key Laboratory for Vessel Integrated Power System Technology | Shi Q.,Xi'an Jiaotong University | Jiang W.,National Key Laboratory for Vessel Integrated Power System Technology
2014 17th International Conference on Electrical Machines and Systems, ICEMS 2014 | Year: 2015

This paper establishes periodic orbit model for the isolated power system (IPS). Stability margin index can be calculated by the model, which represents not only the level of system stability but also the decaying speed of the dynamic response to the increment of state variables. An induced state space average model for IPS is presented based on the periodic orbit model, which is extension of the traditional state space average model. Studies show that the proposed model and algorithm can be used to analyze small signal stability of IPS and design its control strategy. © 2014 IEEE.


Shi Q.,Xi'an Jiaotong University | Wang G.,National Key Laboratory for Vessel Integrated Power System Technology | Fu L.,National Key Laboratory for Vessel Integrated Power System Technology | Yuan L.,National Key Laboratory for Vessel Integrated Power System Technology | Huang H.,National Key Laboratory for Vessel Integrated Power System Technology
IECON Proceedings (Industrial Electronics Conference) | Year: 2013

With the increasing number of variable speed wind turbine generators connect to electrical grid, it is necessary for wind turbines to provide inertia support when the grid frequency drops. Because of its unclear physical concept and time-consuming calculation when the detail simulation model is adopted to deal with the virtual inertia control of the directly-driven wind turbine with permanent-magnet synchronous generator (D-PMSG), it is difficult to design the control scheme and analyze the frequency dynamic response of power systems according to the simulation results. Aiming at the physical essence of wind turbine virtual inertia control, this paper presents a properly-simplified state-space averaging model of the wind power integrated system (WPIS). The model can reflect the dynamic process of virtual inertia control. Based on the model, a linearized model is derived from equation transformation so as to get information about small signal stability. The state-space averaging model established in this paper can provide the technical means for designing the control scheme of virtual inertia control and analyzing the frequency dynamic response of the WPIS. The results of simulation tests have verified the effectiveness of the state-space averaging model. © 2013 IEEE.


Ma W.,National Key Laboratory for Vessel Integrated Power System Technology
APAP 2011 - Proceedings: 2011 International Conference on Advanced Power System Automation and Protection | Year: 2011

The vessel integrated power system (IPS) is the third revolution in the naval vessel power which has evolved from wind power to steam power and then from steam power to nuclear power, marking the trend of naval vessel power. The first-generation IPS has been widely applied to engineering in many countries. However, there are some defects in it such as huge volume, heavy weight and low compatibility when the first-generation IPS is used in light ships, because its power density is limited by the properties of the electromagnetic materials, power electronics, etc. This paper has presented the concept and typical architecture of the second-generation IPS and its technical advantages, introduced several key technologies concerning the second-generation IPS that need a breakthrough according to the current technical level, and pointed out direction of the research and engineering application of the second-generation IPS. © 2011 IEEE.


Fan X.,National Key Laboratory for Vessel Integrated Power System Technology | Wang G.,National Key Laboratory for Vessel Integrated Power System Technology | Fu L.,National Key Laboratory for Vessel Integrated Power System Technology | Yang H.,National Key Laboratory for Vessel Integrated Power System Technology | Ji F.,National Key Laboratory for Vessel Integrated Power System Technology
APAP 2011 - Proceedings: 2011 International Conference on Advanced Power System Automation and Protection | Year: 2011

It is hard to determine critical point of voltage stability exactly for some online voltage stability algorithm and its decision-making time is required to be very small, which hinders its practical application on power system. A novel control strategy of voltage stability based on generator dynamic reactive power releasing is presented to deal with the problem. When voltage collapse happens, stator current and rotor current of generator is increased temporarily to improve its reactive power output, which can restore voltage adjustment capability of those generators whose reactive power has already reached their limit, prevent voltage collapse and achieve much more decision-making time for voltage stability control. Load voltage weak node is identified by coefficient of tangent plane equation of boundary of prefault voltage stability region. Load shedding strategy on load voltage weak node set is calculated by successive optimization algorithm which is implemented after process of generator dynamic reactive power releasing is over. Study shows that the presented control strategy of voltage stability can prevent voltage collapse and provide technical supporting for online application of voltage stability control algorithm, which has been validated by simulation test of IEEE 39 system. © 2011 IEEE.


Hu L.-D.,National Key Laboratory for Vessel Integrated Power System Technology | Sun C.,National Key Laboratory for Vessel Integrated Power System Technology | Chen Y.-L.,National Key Laboratory for Vessel Integrated Power System Technology | Zhao Z.-H.,National Key Laboratory for Vessel Integrated Power System Technology
2014 17th International Conference on Electrical Machines and Systems, ICEMS 2014 | Year: 2015

The on-line measurement of the high-power IGBT collector current is important to the hierarchical control and short-circuit and overcurrent protection of its driver and the sensorless control of the converter. The conventional on-line measurement methods for IGBT collector current are not suitable for engineering measurement such devices as the large-size, high-cost, low-efficiency sensor, current transformer or divider, etc. Based on the gate driver, the paper uses a resistance capacity circuit paralleled with the IGBT power emitter and auxiliary emitter terminals to fulfil the IGBT collector current on-line estimation by measuring the capacity voltage. The theoretical analysis verifies the feasibility of this method. However, the very small resistance of IGBT power emitter leads to the narrow bandwidth of the estimated current. The improved method is adopted to increase the accuracy of current estimation and solve the problem of narrow bandwidth existing in the high-power IGBT steady-state collector current. The simulation and experiment results prove the method to feasible and effective. © 2014 IEEE.


Zhu J.,National Key Laboratory for Vessel Integrated Power System Technology | Nie Z.,National Key Laboratory for Vessel Integrated Power System Technology | Ma W.,National Key Laboratory for Vessel Integrated Power System Technology | Nie S.,National Key Laboratory for Vessel Integrated Power System Technology
IEEE International Symposium on Industrial Electronics | Year: 2012

Due to total harmonic distortion and the time delay of the digital controller in the condition of a single-phase 400 Hz power supply, the traditional proportional-integral-differential controller cannot track the sinusoidal waveforms with zero static error. To improve the performance, the deadbeat control and the proportional-resonant control have been analyzed and contrasted in this paper. The results show that deadbeat control has rapid response but sensitivity to the accuracy of the model and parameters. On this basis, a Dual-Loop Proportional-Resonant control is proposed, which is exercised with the high switching frequency to provide sufficient control bandwidth to reduce the 3rd, 5th and 7th order harmonic. Further, the experiments have been performed on a single-phase 400 Hz power supply prototype. The results show that the Dual-Loop Proportional-Resonant control feeding linear/nonlinear and disturbance loads are satisfactory. © 2012 IEEE.


Wang G.,National Key Laboratory for Vessel Integrated Power System Technology | Ji F.,National Key Laboratory for Vessel Integrated Power System Technology | Xie Z.,National Key Laboratory for Vessel Integrated Power System Technology | Wang R.,National Key Laboratory for Vessel Integrated Power System Technology | Ma H.,National Key Laboratory for Vessel Integrated Power System Technology
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2012

To overcome assessment difficult of harmonic component, small signal stability and dynamic performance of integrated power system including inverter with accuracy and quantifying, periodic orbit model of the system is set forth in this paper. Harmonic component can be calculated by the periodic orbit and small signal stability can be assessed by eigenvalue of Jacobian matrix of its Poincaré mapping. Stability margin index is presented, which can show stability level of the system and quantify decaying speed of dynamic response of state variables increment. Study shows that system stability is mainly decided by DC power supply system and inverter can isolate its oscillation. Also periodic orbit model can quantify influence degree of sampling and modulation mode of inverter and system parameter to inverter performance of integrated power system, which can provide technical supporting to analysis and design of integrated power system. The algorithm has been validated by simulation test. © 2012 Chinese Society for Electrical Engineering.

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