CN2289333Y

CN2289333Y - Device for automatic compensating single phase reactive power

Info

Publication number: CN2289333Y
Application number: CN 96233272
Authority: CN
Inventors: 刘晓勇
Original assignee: KENENG ELECTRIC POWER TECHNOLOGY DEVELOPMENT Co CHONGQING
Current assignee: KENENG ELECTRIC POWER TECHNOLOGY DEVELOPMENT Co CHONGQING
Priority date: 1996-06-11
Filing date: 1996-06-11
Publication date: 1998-08-26
Anticipated expiration: 2006-06-11

Abstract

The utility model relates to a device for automatically compensating single phase reactive power. The utility model is composed of a sampling circuit, a switching controller, an operating mechanism, a parallel connecting capacitor group, and a running indicator, wherein, the switching controller is composed of a stabilized D. C. source, a phase detector, a signal amplifier, a power factor testing circuit, an over voltage and light load testing circuit, a logical drive circuit, and a delay circuit; the operating mechanism adopts a solid state relay for switching capacitor, no contact and no spark exists, no interference for an electric network exists, the capacitor adopts a fully dry and self healing type, and no oil leakage and combustion consideration exists. The utility model has the advantages of reasonable design, stable performance, and safe operation. The utility model can overcome the defects that the user uses the three phase large capacitance reactive compensation. The utility model also has the advantages of higher performance and cost ratio, simple installation, convenient operation, high switching precision, and obvious compensation effect.

Description

Single-phase reactive power automatic compensation case

The utility model relates to and is used to improve power grid quality, reduces the reactive power compensation device of line loss, particularly a kind of single-phase reactive power automatic compensation case that is used for domestic power grid.

The power system reactive power compensation is for improving power grid quality, reducing line loss has enormous function, at present, and in China, generally adopt big electric capacity reactive power compensation on the spot of three-phase or centralized compensation for the compensation of reactive power, this is very suitable for some large-capacity users such as large-scale industrial enterprise.But, along with popularizing of household electrical appliance, home-use electric weight sharply increases, the residential building network load increases the weight of day by day, the overwhelming majority is an inductive load in the household electrical appliance, and power factor is extremely low, and many electric energy are wasted on the transmission line with idle form, usually make utilization voltage low excessively, have a strong impact on the useful life of household electrical appliance.Therefore it is imperative residential building to be carried out reactive power compensation.But, shortcoming such as the power consumption of residential building is compared with industrial enterprise and must be finished too for a short time, if adopt the big electric capacity of three-phase to carry out reactive power compensation on the spot, will have the high difficulty of installing of price, and compensation precision is low.

The purpose of this utility model is: the single-phase reactive power automatic compensation case that provides a kind of suitable residential building domestic power grid to use, it can be according to dwelling house power factor and load size, the automatic switching capacitance group improves power factor, thereby reduces line loss, burning voltage.

The purpose of this utility model is to realize by such technical scheme: promptly the utility model is made up of sample circuit, switching controller, actuator, Shunt Capacitor Unit and operation indication; It is characterized in that: sample circuit is made up of the voltage transformer summation current transformer, and it is with the phase signal of taking, and signals such as load size, voltage height are sent into switching controller; Switching controller is by D.C. regulated power supply, phase discriminator, signal amplifier, detection circuit of power factor, overvoltage detection and underloading testing circuit, logic drive circuit and delay circuit are formed, wherein the input of phase discriminator is connected with the sample circuit signal output part, voltage and current sampling signal translate phase signal are sent into amplifier, detection circuit of power factor detects the signal after amplifying, output driving command signal, power factor smaller or equal to 0.85 input command signal or power factor more than or equal to 0.95 excision command signal, the excision signal of three kinds of command signals and overvoltage and the output of underloading testing circuit connects logic drive circuit, wherein the driving command signal of detection circuit of power factor output connects the delay circuit control end, control logic drive circuit after its time-delay; The drive signal of logic drive circuit output be serially connected in Shunt Capacitor Unit in each electric capacity on, the actuator that forms by solid-state relay and move demonstration and be connected.

Said structure of the present utility model, the embodiment of an indefiniteness that can provide by accompanying drawing further specifies.

The utility model has following accompanying drawing:

Accompanying drawing 1 is a structure principle chart of the present utility model;

Accompanying drawing 2 is the circuit diagram of the utility model switching controller.

Referring to accompanying drawing: present embodiment is made up of sample circuit, switching controller T, the SSR1 of actuator～3, Shunt Capacitor Unit C1～3 and voltage indication and switching indication L1～3.

Sample circuit is made up of voltage transformer VB summation current transformer AL, finishes signals sampling such as phase signal, load size, voltage height, and these signals are sent into switching controller, and its precision directly influences control precision.

Switching controller is made up of D.C. regulated power supply A, phase discriminator B, signal amplifier C, detection circuit of power factor D, overvoltage and underloading testing circuit, delay circuit; Wherein:

Phase discriminator A forms two zero-crossing comparators by integrated transporting discharging LM324 and peripheral circuit.Voltage and current sampling signal translate phase signal are sent into amplifier.

Signal amplifier B is made up of LM324 and peripheral circuit.Respectively phase signal, voltage signal, current signal are amplified, send into three groups of testing circuits then respectively.

Detection circuit of power factor C forms phase place one voltage conversion circuit and comparator circuit by LM324 and peripheral circuit, the phase signal that amplifier is sent here converts the voltage signal that reflects the power factor size to through phase place one voltage conversion circuit, compare with the predetermined electric power factor value again, when power factor COS φ≤0.85, send and drop into instruction B1-2 or when COS φ 〉=0.95, send excision and instruct C1-2, and it is sent into logic drive circuit.

Overvoltage detection and two groups of circuit of underloading testing circuit D are compensation case protective circuit.Its principle is basic identical, forms by LM324 and peripheral circuit thereof.Respectively the voltage B2-1 that sends here and current signal C2-1 and set point are compared, when overvoltage or underloading, send excision instruction D1-2 respectively and it is sent into logical drive.

Logic drive circuit is made up of arithmetic unit E (74LS193), Digital Logical Circuits (74LS10), driver (74LS240) and peripheral circuit.Instruction B1-2, C1-2, D1-2 that three detectors are sent here carry out computing and logical process; And to dropping into or the excision signal is encoded and sent drive signal by binary mode to actuator.

The effect of delay circuit F the command signal A1-2 of detection circuit of power factor is carried out the delay of certain hour, help improving the interference free performance of complete machine like this.It is made of time-base circuit NE555 and peripheral circuit.

The relay SSR1-3 of the drive signal output termination actuator of switching controller, and indicator light L1-3 is indicated and thrown, cut to voltage.

Actuator is made up of solid-state relay SSR1-SSR3, and it is connected on each electric capacity in the shunt capacitance group, and K1-3 connects load by air switch.

The shunt capacitance group adopts dry type, and the self-healing shunt capacitor is safe and reliable to operation.

The utility model adopts strong GMOS integrated circuit of antijamming capability and integrated transporting discharging to form the Automatic Detection and Control circuit of power factor of electric network, the variation of real time automatic detection power factor of electric network, and according to the size of line voltage and load, automatic switching capacitor group, the power factor of raising electrical network; Actuator adopts the solid-state relay switching capacitance, and is furnished with air switch capacitor is protected, and it is contactless to have a switched capacitor, no-spark, thereby to the glitch-free advantage of electrical network.Capacitor adopts state-of-the art in the world dry type self-healing shunt capacitor, the worry of no leakage of oil burning, and whole device line design advanced person, stable performance, safe and reliable to operation.The utility model can overcome the deficiency that the big capacitance reactive compensation device of three-phase exists fully when little user is used, have higher P/C ratio, also has to install simply, and working service is characteristics easily, and switching precision height, and compensation effect is obvious.

Claims

1. single-phase reactive power automatic compensation case, by sample circuit, switching controller, actuator, Shunt Capacitor Unit and operation indication are formed; It is characterized in that: sample circuit is made up of voltage transformer VB summation current transformer AL, and it sends signals such as the phase signal taked, load size, voltage height into switching controller T; Switching controller is by D.C. regulated power supply G, phase discriminator A, signal amplifier B, detection circuit of power factor C, overvoltage and underloading testing circuit D, logic drive circuit E and delay circuit F form, wherein: the input of phase discriminator A and sample circuit signal output part, with voltage and current sampling signal, can send into amplifier by commutation position signal, detection circuit of power factor detects the signal after amplifying, output driving command signal A1-2, power factor smaller or equal to 0.85 input command signal B1-2 or power factor more than or equal to 0.95 excision command signal C1-2, the excision signal instruction D1-2 of three kinds of signals and overvoltage and the output of underloading testing circuit meets logic drive circuit E, wherein A1-2 meets delay circuit F, control logic drive circuit after its time-delay; The logic drive circuit output be serially connected in shunt capacitance group C1-3 in each electric capacity on SSR1-3 of actuator that forms by solid-state relay and operation show that L1-3 is connected.