75 results about "Thyristor switched capacitor" patented technology

An integrated compensation device consists of detection control unit, thyristor switched capacitor module connected to power network and active electric power filter. It is featured as calculating out reactive volume required to be compensated onto load by said device according load current and system voltage as well as object power factor then issuing different switching commands to thyristor switched capacitor module for realizing the switching operation of compensation branch and confirming command signal of compensation current on said filter to make actual output current of said filter track with variation of command current.

The invention discloses a control method for large wind field reactive-load compensation equipment in low voltage ride through. The control method comprises the follow steps that firstly, information of voltage, current, power and frequency in a power grid is sampled through coordination control of an automatic voltage control system, fault points are detected, and when draught fan low voltage ride through starts, a static var generator is rapidly started to provide reactive power; secondly, compensation capacity of various types of reactive-load compensation equipment is determined according to different installation places and effects of the reactive-load compensation equipment and different principles; thirdly, the static var generator respectively achieves the reactive compensation work state and the harmonic suppression work state by using different control strategies; fourthly, the automatic voltage control system starts a thyristor switched capacitor when power voltage is equal to pre-charged voltage of the thyristor switched capacitor; fifthly, the automatic voltage control system starts a thyristor controlled reactor according to reactive gap information; the fourth step and the fifth step are in parallel with each other.

The invention discloses a method for carrying out intelligent control on the dynamic reactive power compensation of a SVG (TSC) (static var generator (thyristor switched capacitor)), which comprises the following steps of: controlling the SVG and the TSC by using a master control unit; carrying out centralized sampling, calculation and control by using the master control unit, and automatically adjusting to adopt a reactive power compensation mode of the SVG and adopt a reactive power compensation mode of the TSC; and preferably starting the reactive power compensation mode of the SVG, and when the SVG has a fault, adopting the reactive power compensation mode of the TSC. When the reactive power demand of a system is instantly changed dynamically, the SVG starts a PWM (pulse-width modulation) control program at a predetermined response speed firstly, and then outputs compensation currents so as to rapidly and dynamically adjust the variable quantity of reactive power; and when the load of the electric power system is changed within a large range and exceeds the capacity of the SVG, a grouping switch function of the TSC is started so as to compensate the reactive power demand of the system. The method for carrying out intelligent control on the dynamic reactive power compensation of the SVG (TSC), disclosed by the invention, has the advantages that: the response speed of reactive power compensation can be improved, an effect of carrying out dynamic and continuous adjustment on reactive power can be achieved, and the like.

The invention relates to a low voltage ride through (LVRT) control system of a fixed-blade stalling type wind generating set. The LVRT control system comprises a thyristor switched capacitor (TSC) type static var compensator (SVC), a revolution speed transducer and an intelligent controller, wherein the revolution speed transducer is installed on a squirrel-cage asynchronous generator; the intelligent controller is used for realizing LVRT control; the TSC type SVC is connected to the three-phase line of the squirrel-cage asynchronous generator and comprises n numbered groups of capacitors which are connected in parallel, and a single group of capacitors are connected with a bidirectional thyristor in series; and the intelligent controller comprises a revolution speed acquiring module, a revolution speed impedance characteristic computing module and a capacity allocating module, the revolution speed impedance characteristic computing module is used for computing the target equivalent capacitive impedance according to revolution speed signals and the inherent characteristic parameters of a motor, and the capacity allocating module is used for allocating each group of capacitors needing to be put into operation according to the computed target equivalent capacitive impedance and sending a closing instruction to the corresponding bidirectional thyristor. According to he invention, good control effect is realized on the premise of lower cost.

The invention discloses a novel dynamic TSC (thyristor switched capacitor) and SVG (static var generator) hybrid reactive compensation device and method. The device comprises an SVG controller, an SVG power unit and TSC branches, wherein the SVG power unit comprises a breaker, a current sampling unit, an electric reactor and an IGBT (insulated gate bipolar transistor) module. The SVG controller is used for calculating reactive power demanded by a system; voltage fluctuation and flicker are inhibited in time due to the characteristic of high dynamic response speed of an SVG, and after a load is stabilized, the TSC branches are put into use to reduce reactive power provided by the SVG; after the load is shut off, excessive reactive power is quickly absorbed through dynamic response of the SVG, and then the TSC branches are cut off step by step. The characteristic of high dynamic response speed of the SVG can be used to inhibit the voltage fluctuation and flicker, and meanwhile, the defect of insufficient SVG capacity can be overcome; and meanwhile, the SVG works in a low load state, the service life of the SVG is prolonged, accurate compensation can be realized, and the inhibition capacity of voltage fluctuation and flicker is greatly improved.

The invention discloses a TSC (thyristor switched capacitor) switching method, a terminal device and a computer readable storage medium. The method comprises when the terminal device receives a switching signal, determining whether a current capacitor residual voltage value is less than a current grid voltage peak value; when the current capacitor residual voltage value is less than the current grid voltage peak value, determining whether a phase difference between a current grid voltage phase and a current capacitor phase is within a preset angle range; and when the phase difference is withinthe preset angle range, sending a pulse signal to the target TSC in order that the target TSC is turned on after receiving the pulse signal. The method can improve the accuracy of zero-cross detection, shortens switching time, increases switching speed and efficiency, and avoids the impact of inrush current on the grid.

The invention discloses a mixed power quality treatment method. In an active part, at least two groups of static var generators and at least two groups of active power filters are connected to a three-phase power network in a transformer isolation mode, wherein the static var generators mainly compensate reactive current, the active power filters compensate harmonic current, and when the voltage dips seriously, the active power filters can also make up for the deficiency of the static var generator capacity; and in a reactive part, a directly hung static var generator combined by a thyristor-controlled electric reactor and a thyristor switched capacitor, as well as a fixed capacitance compensator is directly connected to the three-phase power network for reactive compensation, three-phase unbalance is compensated, the thyristor switched capacitor provides large-capacity capacitive reactive power, the fixed capacitance compensator provides small-capacity reactive power, and the fixed capacitance compensator also serves as a main subharmonic filtering subcircuit of the thyristor-controlled electric reactor for coordinative comprehensive compensation and harmonic treatment of a power system.