CN2458632Y

CN2458632Y - Three-phase input switch rectifier detector for testing substration phase

Info

Publication number: CN2458632Y
Application number: CN 00267945
Authority: CN
Inventors: 张建利
Original assignee: BEIJING TONGLIHUAN ELECTRICAL Co Ltd
Current assignee: BEIJING TONGLIHUAN ELECTRICAL Co Ltd
Priority date: 2000-12-28
Filing date: 2000-12-28
Publication date: 2001-11-07
Anticipated expiration: 2010-12-28

Abstract

The utility model relates to an open-phase detector of a three-phase input switch rectifier, which is formed by orderly connecting a three-phase full-bridge rectifier, a signal detection isolation circuit and a memory circuit in series, wherein, the signal detection isolation circuit is formed by the serial connection of an optical coupler and a voltage stabilizer, and the output of the optical coupler is connected with the input of the memory circuit. Voltage waveform which is rectified in a full-bridge way in a three-phase electric network is utilized fully, and the open phase of the electric network is detected through a certain discrimination and processing circuit. The utility model has the advantages of simple circuit and reliable operation.

Description

Three-phase input switch rectifier phase loss detector

The utility model relates to three-phase input switch rectifier lack detection circuit.

In the communication power supply field, three-phase does not have the relative single-phase switch rectifier of center line switching rectifier, because of thoroughly having solved the big and three-phase current unbalance problem of current in middle wire, so be widely used in recent years.But do not have the center line switching rectifier for three-phase, the electrical network phase shortage will be the problem that must face, especially adopt the switching rectifier of Passive Power alignment technique, and the grid side harmonic current increases during phase shortage, and power factor reduces.Therefore a cover improves and lack detection circuit is extremely important for three-phase does not have the center line switching rectifier accurately.

In view of above-mentioned, the purpose of this utility model provides a kind of three-phase input switch rectifier lack detection circuit, and it can provide default phase signal accurately.

The purpose of this utility model provides following technical scheme to realize:

A kind of three-phase input switch rectifier phase loss detector, it is characterized in that: it is followed in series to form by three-phase full-bridge rectifier, input buffer circuit, memory circuit, the input buffer circuit is composed in series by optical coupler and voltage stabilizer, and the output of optical coupler connects the input of memory circuit.

Described memory circuit is made of trigger.

The output of described optical coupler connects the pulse signal input terminal of trigger through phase inverter, and the signal input part of trigger connects high level, set termination power ground, the electrify restoration circuit that the termination that resets is composed in series by capacitance resistance.

Because the utility model adopts the waveform of three-phase supply after full-bridge rectification carried out phase shortage detection discriminating, again through light-coupled isolation, be stored in the mode in the memory circuit then, used each element circuit all has characteristics simple in structure, reliable operation, and circuit is simple, the advantage of reliable operation so have.

Describe in detail below in conjunction with drawings and Examples.

Fig. 1 is a circuit diagram of the present utility model;

Fig. 2-Fig. 4 is the oscillogram among Fig. 1.

The utility model three-phase input switch rectifier phase loss detector is followed in series to form by three-phase full-bridge rectifier, input buffer circuit, memory circuit, the input buffer circuit is composed in series by optical coupler and voltage stabilizer, and the output of optical coupler connects the input of memory circuit.

In Fig. 1: diode V1-V6 constitutes three-phase bridge rectification circuit, and its output adds to the input buffer circuit.Resistance R 1 and R2, optical coupler N1, stabilivolt V ₇Form the input buffer circuit, finish default phase signal and detect isolation, its output adds to memory circuit.D type flip flop constitutes memory circuit, realizes the triggering memory of default phase signal.Wherein: the output of optical coupler N1 meets the pulse signal input terminal CP of trigger D1 through phase inverter N2, and the signal input part D of trigger D1 connects high level, and set end S connects power supply ground, and reset terminal R connects the electrify restoration circuit that is composed in series by capacitor C 1 and resistance R 3.

Foregoing circuit can be contained in the shell.

Under the normal condition of three phase network, the voltage waveform between 2 of A, the B is a continuous direct current fluctuation voltage as shown in Figure 2, and minimum point is 0.866 times of line voltage, and peak is 1.414 times of line voltage.The fluctuation range of the interchange input line voltage that allows according to switching rectifier, the voltage stabilizing value VR of choose reasonable voltage stabilizing diode V7 and the resistance of current-limiting resistance R1, guarantee reliably conducting of photoelectrical coupler N1, then the point of the C among Fig. 1 is that high level, D point are low level, reset mode when trigger keeps powering on, the E point continues as low level, and back level high frequency DC/DC translation circuit allows to start.

Under the situation of three phase network generation phase shortage, the voltage waveform between 2 of A, the B as shown in Figure 3.At this moment three-phase bridge rectification circuit has become the single-phase full bridge rectification circuit, therefore the waveform after the rectification has zero crossing to exist, C names a person for a particular job and as shown in Figure 4 square wave voltage waveform occurs, trigger D1 will overturn, the E point becomes high level, back level high frequency DC/DC translation circuit will be under an embargo, and switching rectifier is closed.

To sum up, principle of the present utility model is to make full use of the later voltage waveform of three phase network full-bridge rectification, through certain discriminating treatment circuit, comes the phase shortage of detection of grid.

Above embodiment for explanation the utility model, is not to be used for limiting claim of the present utility model only, and therefore, the improvement of any unsubstantiality of doing based on the utility model and prior art surely belongs within the scope of patent protection of the present utility model.

Claims

1. three-phase input switch rectifier phase loss detector, it is characterized in that: it is followed in series to form by three-phase full-bridge rectifier, input buffer circuit, memory circuit, the input buffer circuit is composed in series by optical coupler and voltage stabilizer, and the output of optical coupler connects the input of memory circuit.

2. three-phase input switch rectifier phase loss detector as claimed in claim 1, it is characterized in that: described memory circuit is made of trigger.

3. three-phase input switch rectifier phase loss detector as claimed in claim 2, it is characterized in that: the output of described optical coupler connects the pulse signal input terminal of trigger through phase inverter, the signal input part of trigger connects high level, set termination power ground, the electrify restoration circuit that the termination that resets is composed in series by capacitance resistance.