33results about How to "Improve the quality of supply voltage" patented technology

The invention discloses a network reconfiguration method and system of an urban distribution network. The method includes: establishing the multi-objective optimization function of the system's annual power shortage, the system's average power-off duration, the system's average power-off frequency, and the minimum network loss of the urban distribution network; determining the constraints of the multi-objective optimization function and each objective The weight of the optimization function; set the on-off initial value of the switch of each load node in the urban distribution network; according to the on-off initial value of the switch of each load node, multi-objective optimization function and constraint conditions, adopt the method based on decomposition and The multi-objective particle swarm optimization algorithm of differential evolution solves the multi-objective optimization function; according to the on-off of the switch of each load node in the urban distribution network corresponding to the solution of the weighted and minimum multi-objective optimization function, the urban distribution network network refactor. The invention can optimize the network loss of the urban distribution network containing the distributed power supply and the automobile charging station, reduce the operation cost, and improve the quality of the power supply voltage of the urban distribution network at the same time.

The present invention proposes a distribution network voltage quality improvement method based on single-phase photovoltaic inverters, which comprehensively applies multiple single-phase photovoltaic inverters distributed in the distribution network, and uses single-phase photovoltaic inverters to form Multiple distributed delta compensation groups and multiple distributed star compensation groups. Each distributed delta compensation group performs on-site compensation for three-phase voltage imbalance, and multiple distributed star compensation groups cooperate to compensate for voltage deviations in the distribution network, and single-phase photovoltaic inverters exchange reactive power through a local communication network Utilization rate information, adopt distributed consensus algorithm to calculate reactive power reference value, realize fairness in the same sense of reactive capacity utilization rate while compensating for voltage deviation.

The invention relates to the field of power supply and distribution technology, and discloses a method for realizing self-adapting network reconfiguration at a distribution network terminal. The method is characterized by comprising the followings steps of: (a) constructing an input vector and an output vector of a distribution network terminal neural network module; (b) initializing a neural network; (c) training the neural network by using samples; and (d) treating the distribution network for reconfiguration with the trained neural network module. The invention has the benefits of buildingthe corresponding relation between a dynamic distribution network load and an optimal network topology by using the nonlinear mapping relationship between the input and output of the neural network and the self adapting self-learning ability to realize the reconfiguration of the distribution network, thereby reducing the line loss of the distribution network and improving the system economy, balancing the loads, eliminating the overload, improving the voltage quality of supplied power, and further improving the reliability of the supplied power.

The embodiment of the invention provides a multifunctional fault current active regulation current-limiting system. One end of a first filtering module is connected with one phase of a to-be-controlled power grid by a first inductor; one end of a first dynamic voltage compensation module is connected with a first end of a first current-limiting module; the other end of the first dynamic voltage compensation module is connected with a second end of the first current-limiting module; both ends of a voltage stabilization capacitor are respectively connected with a third end of the first current-limiting module and a second end of the first current-limiting module; an energy storage module is respectively connected with both ends of the voltage stabilization capacitor; if the to-be-controlledpower grid normally operates, the first current-limiting module is turned off, and dynamic voltage compensation is carried out on the to-be-controlled power grid by the first dynamic voltage compensation module. According to the invention, a short-circuit current under a fault that a short circuit occurs to a single feeder or short circuits simultaneously occur to both feeders can be effectively inhibited; voltage rising, falling and three-phase voltage unbalance dynamic compensation on double feeders are implemented, the voltage compensation depth is improved, and a fault overcurrent is inhibited.

The invention discloses a cordwood power capacitor, comprising three and more than three cordwood power capacitor modules; the cordwood power capacitor modules are connected and assembled by a bolt to form a capacitor bank; the cordwood power capacitor modules are in bolted connection with post insulators; sleeve tubes are arranged on the cordwood power capacitor modules; the sleeve tubes are wire inlet and outlet terminals of the cordwood power capacitor modules; and the cordwood power capacitor modules and the capacitor bank realize electrical connection through a bus bar. The cordwood power capacitor has the advantages of simplicity in installation and maintenance, low noise, convenience in capacity extension and renovation as well as long service life.

The invention discloses an AC and DC power supply system, which includes: installing a grounding device between the AC system and the converter system, and the grounding device is also connected to the neutral line and the earth, so as to provide the neutral line and the grounding point for the converter system, The wiring mode of the converter system is not limited to the three-phase three-wire system; the common mode voltage elimination circuit is connected to the AC side and the DC side of the converter system, and the common mode voltage elimination circuit is not limited to suppressing the common voltage between the AC and DC sides of the converter system. mode voltage, and at the same time induce the corresponding proportion of reverse common-mode voltage, and connect it in series to the DC bus and ground loop, so as to realize the elimination of the common-mode voltage of the converter system to the ground.

The invention discloses a comprehensive reactive power voltage-regulation compensation device of a power distribution network for a tail-end concentrated load. The comprehensive reactive power voltage-regulation compensation device comprises a compensation system and a control system, wherein the compensation system comprises a capacitor, a damping loop, a voltage limiter, a bypass circuit breaker, a controllable circuit breaker and a rapid switch and is used for improving voltage quality under continuous running voltage, and the control system comprises a current transformer, a voltage transformer, a voltage comparator, power factor monitoring equipment, a power factor comparator, a logic operation circuit and a trigger circuit. In the device, series capacitance compensation or parallel capacitance compensation working state is adjusted by the controllable circuit breaker and by identifying a voltage and power factor of a load, so that the adaptability and the reliability of reactivepower compensation are ensured. The comprehensive reactive power voltage-regulation compensation device is mainly used for improving the electric energy quality of the power distribution network and is particularly suitable for voltage compensation of a concentrated large load of which the load is concentrated at a tail end of a power distribution network line and which is low in power factor.

A low-voltage control method for rural power grids. Rural power grids are equipped with four-level control equipment from substations to low-voltage lines supplied to users, which are the first-level on-load voltage regulation and substation centralized compensation devices for regulating substations. The second-stage multi-stage line reactive power compensation device for medium-voltage lines, the third-stage on-load tap-changing transformer for regulating and controlling distribution stations, and the fourth-stage low-voltage reactive power compensation device for regulating and controlling low-voltage lines; There is a low-voltage monitor, and the low-voltage monitor and each level of control equipment are connected to the control and management master station through the network or wireless communication. In the present invention, when the low-voltage monitor detects that the low voltage somewhere in the line is abnormal, the regulation and management master station regulates the equipment closest to the place where the voltage occurs in the order from the last stage of the line to the high-level voltage, and the adjusted voltage value is transmitted to the regulation and management In the master station, compare the reference value of the voltage data in it, and if it meets the standard, start monitoring again; otherwise, the line alarms.