CN2087838U

CN2087838U - Imaginary power compensator

Info

Publication number: CN2087838U
Application number: CN 91201884
Authority: CN
Inventors: 孙少凡; 陆迎
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-02-01
Filing date: 1991-02-01
Publication date: 1991-10-30

Abstract

Disclosed is a device for compensating reactive power, belonging to the technical field of electric control apparatuses. The utility model is characterized in that an automatic manual switching circuit comprises normally open connecting keys AQ[+], AQ[-] triggers D[1], D[2] and double-blade press-button switches K[11], K[12]; an automatic reset circuit comprises monostable triggers T[1], T[2], time delay circuits R[1], C[1], R[2], C[2]and a reverser F. The utility model has the advantages of high reliability, strong anti-interference performance, simple structure, etc.

Description

Imaginary power compensator

Reactive power compensation device belongs to automatically controlled instrument field.

Existing reactive power is mended the device major part and is all adopted multichannel to remove the access of switch control capacitor and excision, so exist the intermediate link contact many, often occurs that contact is bad, fragile, poor reliability, spark be big, to shortcomings such as networking generation impulse disturbances.

The purpose of this utility model: a kind of manual control is provided, and only replacing all each roads by two buttons removes a switch, the reactive power compensation device that can automatically reset and restart when computer is locked by unexpected disturbances.

Content of the present utility model: reactive power compensation device by amplifying circuit, waveform transformation circuit, AND circuit, voltage conversion circuit, integrating circuit, comparison circuit, automatically-manual switching circuit, single chip microcomputer, display circuit, actuator, net press observation circuit, warning circuit, automatic reset circuit, guidance panel is formed.It is characterized in that automatic-manual switching circuit is by normal key point AQ ⁺, AQ ^-, trigger D ₁, D ₂, double-pole key switch K ₁₁, K ₁₂Form.Automatic reset electro route monostable flipflop T ₁, T ₂, time delay circuit R ₁C ₁, R ₂C ₂, reverser is formed.

Good effect of the present utility model: this reactive power compensation device have reliability height, strong anti-interference performance, simple in structure, easy and simple to handle, cost is low, volume is little.

Description of drawings:

Fig. 1 is a whole theory diagram of the present utility model.

Fig. 2 is the circuit diagram of automatic-manual switching circuit.

Fig. 3 is the circuit diagram of automatic reset circuit.

Fig. 4 is the front elevation of guidance panel.

Embodiment:

Reactive power compensation device by amplifying circuit 2, waveform transformation circuit 3, AND circuit 4, voltage conversion circuit 5, integrating circuit 6, comparison circuit 7, automatically-manual switching circuit 8, single chip microcomputer 9, display circuit 10, actuator 11, net press observation circuit 12, warning circuit 13, automatic reset circuit 14, guidance panel is formed, as shown in Figure 1.Its operation principle is as follows: the electric current in the network draws electric current through instrument transformer 1

, electric current

And voltage After passing through amplifying circuit 2, voltage conversion circuit 5, waveform transformation circuit 3 respectively, change square-wave signal I and the U identical into network.This two paths of signals forms electric current through AND circuit 4 With voltage Phase signal IU.Can be found out that by mesh current, voltage phase difference measuring principle among Fig. 1 when power factor was 1, its phase signal was 90 degree just, phase difference is an inductive load when spending less than 90, and phase difference is a capacitive load when spending greater than 90.IU is admitted to the INT of single chip microcomputer 9 at last ₀End (as Fig. 2).Present embodiment adopts the mode of counting to ask for power factor value, at first utilizes single chip microcomputer 9 internal counter T ₀To INT ₀The IU deration of signal (being phase difference) of end input adopts counting mode to measure, and because of count cycle of single chip microcomputer 9 internal counters is 2 microseconds, so each count value is equivalent to the phase differences of 0.0 36 degree, resolution is very high.Single chip microcomputer 9 is converted into phase difference according to last count value, and for example the count value of the phase angle of 90 degree is 2500.In the present embodiment, 9 couples of INT of single chip microcomputer ₀The IU signal continuous sampling of end input seven times is removed two maximums and two minimum values in seven times then, and the mean value of three values is scaled power factor value with this value and send display 10 in the middle of getting again, and preparation and set-point comparison.

Square-wave signal U after the conversion of integrating circuit 6, comparison circuit 7, is transformed into the square-wave signal U of a variable-width again _d, U _dWidth adjustable continuously between 1 to 5 millisecond, be equivalent to electrical degree 18 degree just to 90 degree.Therefore, can artificially set its numerical value, come the power factor value of Control Network as the set-point of power factor.U _dEnter the INT of single chip microcomputer 9 through automatic-manual switching circuit 8 ₁End utilizes single chip microcomputer 9 internal counter T ₁To U _dWidth carry out counting mode and measure its principle and above-mentioned T ₀The course of work of counter is identical.Single chip microcomputer 9 is according to instruction, with T ₁Count value of counter (set-point) and T ₀The count value of counter (measured value) compares, and determines whether by the capacitor group in actuator 11 inputs or the excision network according to comparative result.For fear of the vibration situation occurs in comparison point, present embodiment provides a minimum value △, and promptly 0.6 degree≤△≤2 are spent, and this device can be selected the △ value according to the actual conditions of offered load, set-point U automatically _dTwo kinds of possibilities are arranged, one with the comparative result of measured value IU: if | U _{D ￣}IU|＜△ illustrates that two values are close, and network need not compensate, and the attitude of remaining stationary is constant.Its two: if | U _{D ￣}IU|＞△ then advances a relatively U _dThat is big with the value of IU, if U _dValue greatly then illustrates the network undercompensation, needs to drop into the capacitor group, otherwise, big as the IU value, the network overcompensation is described, need excision capacitor group.Single chip microcomputer 9 provides command adapted thereto according to comparative result, control actuator 11.The capacitor group adopts the periodic duty mode, the excision earlier that promptly drops into earlier, and the back excision that drop into the back makes the access probability of each capacitor group identical.

Voltage signal U send net to press observation circuit 12 behind voltage conversion circuit 5, and net is pressed the output of observation circuit 12 deliver newspaper alert circuit 13 and single chip microcomputer 9.In case net press to surpass permissible value, warning circuit 13 flashing light alarms, and cut off the capacitor group of all input by microcomputer, up to net press recover normally after, again according to set-point U _d, provide compensation.

Automatically-manual switching circuit 8 is for giving full play to the function of single chip microcomputer 9, abandons in other reactive power compensator all each roads and manually removes a switch, the substitute is two buttons.Automatically-and circuit diagram such as Fig. 2 of manual switching circuit 8, it is by often opening button AQ ⁺, AQ ^-, trigger D ₁, D ₂, double-pole key switch K ₁₁, K ₁₂Form.Often open button AQ ⁺, AQ ^-Be attempted by trigger D ₁CP end, AQ ^-The other end be connected on the output of the output of waveform transformation circuit 3 and AND circuit 4, integrating circuit 6, AQ ⁺The other end be connected on the output of comparison circuit 7, trigger D ₁, D ₂Form series connection four divided version, double-pole key switch K ₁₁And K ₁₂Be connected on the INT of single chip microcomputer 9 respectively ₁End and P _3,7End, K ₁₁Can invest D ₂Q end or the output of comparison circuit 7, K ₁₂Can invest power supply E or through resistance R ground connection.

Its operation principle is as follows: present embodiment single chip microcomputer 9 adopts 8031, as double-pole key switch K ₁₁, K ₁₂When placing position 2, single chip microcomputer 8031 is by identification pin P _3,7Level change, learn that control device will carry out manual compensation, at this moment, INT ₁Pin is waited for D ₂Q end output square wave, because of AQ ⁺, AQ ^-Be and often open button, so when they are not pressed, D ₂Do not have square wave output, single chip microcomputer 8031 to be in wait period, can only carry out the power factor value of real time monitoring network, and show its value.When pressing AQ ⁺Or AQ ^-During arbitrary key, D ₂Q end output square-wave signal, 8031 responses at once, to the sampling of input square wave, digital filtering is got computings such as its mean value.Single chip microcomputer only needs to judge it is to drop into according to input square width difference, still excises the capacitor group.Because square-wave signal U is

Obtain by voltage transformation, shaping.The width of its square wave is the half period of network just.Be equivalent to 18 degree electrical degrees, and square wave U _dBe U by integration, relatively obtain, its Breadth Maximum is four/one-period, is equivalent to 90 degree electrical degrees, U and U _dWidth differ one times, single chip microcomputer does not hold consciousness not very much.For example, press AQ when hand ⁺The time, this device inserts No. one capacitor group automatically, if always according to AQ ⁺, then just inserted one group, up to whole accesses every 2.5 seconds.Otherwise, if according to AQ ^-, then by road excision capacitor group.Meanwhile, digital display tracing display AQ ⁺, AQ ^-Operating result.This frame mode avoids using multichannel contact switch, has improved the reliability of device.The guidance panel of present embodiment such as Fig. 4.Button on the panel+and-be connected to and often open button AQ ⁺And AQ ^-Automatic, manual button on the panel is corresponding to K ₁₁And K ₁₂Self-sustaining double-pole key switch, when not connecing this key, be equivalent to automatically, this moment, this device detected and the switch capacitor group automatically.When pressing this key, be equivalent to manually.Preceding 3 of digital display show power factor, and back two show the capacitor group number that inserts.

For preventing that this device from making microcomputer the deadlock phenomenon cisco unity malfunction occur being subjected to unexpected disturbances, so set up automatic reset circuit 14, its circuit diagram such as Fig. 3.It is by monostable flipflop T ₁, T ₂, time delay circuit R ₁C ₁, R ₂C ₂, inverter F forms.T ₁Q termination T ₂TR ^-End, T ₂Q ^-The input of termination inverter F, the RST end of the output order sheet microcomputer 9 of F, the P of single chip microcomputer 9 _3,4Termination T ₁TR ⁺End, T ₁Delay circuit by R ₁, C ₁Form T ₂Delay circuit by R ₂C ₂Form.

The operation principle of automatic reset circuit 14 is as follows: when 8031 work, and its pin P _3,4Output pulse sequence enters T ₁TR ⁺End makes T ₁Be in temporarily steady state, the Q end is output as high level.When unexpected disturbances makes 8031 when locked, P _3,4End stops to export pulse, T ₁Get back to stable state by original transient state, Q holds through TW ₁The back becomes low level (TW by high level ₁=0.69R ₁C ₁).Because T ₁Q end by high step-down, the T that trailing edge is triggered ₂Become transient state by stable state, T ₂Q ^-End becomes low level by high level, through TW ₂(TW ₂=0.69R ₂C ₂) T after the time ₂Return to stable state.Because the effect of inverter F, the output of inverter F becomes high level by low level, through TW ₂Become low level after time.Because the output of inverter F is connected to 8031 reset terminal RST,, guaranteed the normal operation of this device so this direct impulse makes 8031 to reset and restart.

Claims

1, reactive power compensation device belongs to automatically controlled instrument field, it by amplifying circuit 2, waveform transformation circuit 3, AND circuit 4, voltage conversion circuit 5, integrating circuit 6, comparison circuit 7, automatically-manual switching circuit 8, single chip microcomputer 9, display circuit 10, actuator 11, net press observation circuit 12, warning circuit 13, automatic reset circuit 14, guidance panel to form, it is characterized in that:

A, automatic-manual switching circuit 8 are by often opening button AQ ⁺, AQ ^-, trigger D ₁, D ₂, double-pole key switch K ₁₁, K ₁₂Form;

B, automatic reset circuit 14 are by monostable flipflop T ₁, T ₂, time delay circuit R ₁, C ₁, R ₂, C ₂, reverser F forms.

2, reactive power compensation device according to claim 1 is characterized in that:

A, automatically-manual switching circuit 8 often open button AQ ⁺, AQ ^-, be attempted by trigger D ₁CP end, AQ ^-The other end be connected on the input of the output of waveform transformation circuit 3 and AND circuit 4, integrating circuit 6, AQ ⁺The other end be connected on the output of comparison circuit 7, trigger D ₁, D ₂Form series connection four divided version, double-pole key switch K ₁₁And K ₁₂Be connected on the INT of single chip microcomputer 9 respectively ₁End and P _3,7End, K ₁₁Can invest D ₂Q end or the output of comparison circuit 7, K ₁₂Can invest power supply E or through resistance R ground connection;

The monostable flipflop T of b, automatic reset circuit 14 ₁Q termination T ₂TR ^-End, T ₂Q ^-The input of termination inverter F, the RST end of the output order sheet microcomputer 9 of F, the P of single chip microcomputer 9 _3,4Termination T ₁TR ⁺End, T ₁Delay circuit by R ₁C ₁Form T ₂Delay circuit by R ₂C ₂Form.

3, reactive power compensation device according to claim 1, it is characterized in that automatically-manual switching circuit 8 often open button AQ ⁺And AQ ^-Button on the difference attended operation panel+and-; Automatic, manual button on the guidance panel is corresponding to K ₁₁And K ₁₂Self-sustaining double-pole key switch.