Research And Application Of STATCOM Key Technology For Underground Winch Load

Since the downhole winch adopts frequency conversion speed regulation,the active and reactive impacts are large when the heavy load starts,which will cause a large voltage drop,accompanied by a large number of integer and non-integer multiple harmonic currents,resulting in serious harmonic pollution and power.Low factors,severe voltage fluctuations,equipment failure to start and damage,etc.,make the power supply safety of the underground power grid a hidden danger.In the underground winch power supply grid,it is especially important to improve the power factor,control the harmonic pollution,and stabilize the grid voltage.The static synchronous compensator(STATCOM)can effectively compensate the reactive power,compensate the harmonics,and improve the transient voltage stability of the power system.STATCOM,which is used for downhole winch load,is an important power electronic converter device that combines reactive power compensation,harmonic control and voltage stability.It is a research hotspot of modern reactive power compensation and harmonic control technology.This paper takes the explosion-proof chain STATCOM as the background,and focuses on its key technologies and applications under the load of winch.It has typical engineering practice characteristics and has high application prospect and value.Firstly,for the STATCOM phase-locked loop control,DC capacitor ripple control,voltage loop controller design,dual-loop controller design,multiple task mode switching and dynamic limiting and other key algorithms and control techniques,in terms of implementation methods and simulation verification Do a more in-depth study.Through simulation and comparison analysis,the input signal is used for fixed sampling and synchronous sampling.In the case of harmonics,unbalance,step and compound,the performance of the phase-locked loop is verified to meet the requirements.Various methods are also given.Relationship and application.In order to analyze the DC capacitor ripple,the dynamic equivalent capacitance of the chained STATTCOM is quantitatively analyzed and calculated,and the ripple peak characteristics of the three DC capacitor ripple control methods are analyzed and compared,and the ripple control method is obtained.The best method: the double frequency power distribution method.For the voltage loop,different types of controllers are used,and the simulation performance is analyzed.There are some differences in the control performance.The simulation results show that PD is relatively optimized to meet the design and actual needs.The parameters of the double-loop controller were quantitatively designed.Through simulation and comparison analysis,the optimal design value was obtained,which is universal and can be used for reference.Aiming at the practical engineering application of STATCOM,the task planning with multi-mode switching and its concrete implementation are proposed.The specific implementation of priority is proposed for dynamic limiting.The simulation shows that it meets the requirements.Then,the design and application of STATCOM's explosion-proof lock,heat sink,laminated busbar,reactor,filter and other key components have been studied in-depth.In order to solve the problem of energy release during explosion-proof STATCOM opening,to meet the conditions of downhole use,a linkage blocking discharge device was designed and implemented.In order to solve the heat dissipation requirements of the explosion-proof STATCOM,the heat dissipation design and analysis were carried out,and the results showed that the temperature rise satisfies the requirements.The laminated busbar is a carrier fluid between the IGBT and the DC capacitor.The design shows that the current carrying capacity,temperature rise and self-inductance meet the requirements.Reactors have various considerations in terms of inductance,temperature rise,size,etc.,and are designed to meet the requirements.The advantages and disadvantages of various forms of the filter are analyzed,and quantitative analysis is carried out to conclude that the LCL is optimal.Finally,the STATCOM under winch load has been deeply studied in practical engineering applications such as electromagnetic compatibility,transient voltage stability and harmonic control.In the engineering practice of STATCOM under the load of downhole winch,the winch starting characteristics,especially the transient inrush current,are analyzed by theory and simulation,indicating that the reactive impact is large.Through simulation analysis,taking the target voltage function,it is possible to control the transient voltage and stabilize the voltage,thereby alleviating the problem of the impact voltage drop of the winch motor starting.The theoretical analysis and field measurement of the harmonics are carried out first.The simulation and experimental verification show that the harmonic compensation effect is good.