CN201207566Y

CN201207566Y - Short circuit protection circuit in inverter

Info

Publication number: CN201207566Y
Application number: CNU2008200592555U
Authority: CN
Inventors: 洪伟弼
Original assignee: New Focus Lighting and Power Technology Shanghai Co Ltd
Current assignee: New Focus Lighting and Power Technology Shanghai Co Ltd
Priority date: 2008-05-30
Filing date: 2008-05-30
Publication date: 2009-03-11
Anticipated expiration: 2018-05-30

Abstract

The utility model relates to a short-circuit protection circuit in an inverter power supply, which comprises: a full-bridge rectifier (1) and a filter capacitor (2) which rectify alternating current high voltage into direct current high voltage; the circuit also includes a voltage division circuit (30); two ends of the voltage division circuit (30) are connected with two ends of the filter capacitor (2); the voltage division circuit (30) is connected with an MCU circuit (40) after voltage division; a full-bridge output circuit (50) is connected with an anode of the filter capacitor (2); and the utility model has the advantages that: the current short circuit status can be reflected intuitively through the fluctuation of direct current bus voltage, links of transformation are reduced, the short circuit is more reliable, and the cost is reduced.

Description

Short-circuit protection circuit in the inverter

Technical field

The utility model relates to a kind of inverter, relates in particular to short-circuit protection circuit in a kind of inverter.

Background technology

Because in the current inverter, mostly adopt current sensor to carry out the collection of short-circuit signal, so not only the current signal that short circuit is produced converts voltage signal to, the restriction of the precision of the device that also can be subjected to sampling, and can increase cost, when debugging, increase debugging difficulty.

As seen from Figure 1: full-bridge rectification 1 and filter capacitor 2 are rectified into high direct voltage with ac high-voltage; high direct voltage is through full-bridge output circuit 3; inversion is output as interchange, and current sensor 4 is converted to voltage signal with current signal in the loop, sends into identifying unit 5 then and judges short-circuit protection.

But this short-circuit protection; be earlier the short circuit current signal to be converted to the voltage signal that can judge through over-current sensor; when voltage signal is more weak relatively; also will increase voltage amplifier circuit in decision circuit is judged again; in this process, be subjected to the influence of sensor accuracy and amplifying circuit; relatively complicated in debug process, and current sensor has increased circuit cost.

Summary of the invention

The utility model technical issues that need to address have provided short-circuit protection circuit in a kind of inverter, are intended to solve the above problems.

In order to solve the problems of the technologies described above, the utility model is achieved through the following technical solutions:

The utility model comprises: full-bridge rectification and filter capacitor are rectified into high direct voltage with ac high-voltage; Also comprise a bleeder circuit; Two ends of described bleeder circuit and two ends of filter capacitor 2 join; Join with the MCU circuit after the described bleeder circuit dividing potential drop; The positive pole of full-bridge output circuit and filter capacitor joins.

Compared with prior art, the beneficial effects of the utility model are: current short-circuit state has been reacted in the fluctuation by DC bus-bar voltage intuitively, has reduced transform part, makes short circuit more reliable, and cost reduces.

Description of drawings

Fig. 1 is the inverter module map;

Fig. 2 is a line map of the present utility model;

Embodiment

Below in conjunction with accompanying drawing and embodiment the utility model is described in further detail:

As seen from Figure 2: the utility model comprises: full-bridge rectification 1 and filter capacitor 2 are rectified into high direct voltage with ac high-voltage; Also comprise a bleeder circuit 30; Two ends of described bleeder circuit 30 and two ends of filter capacitor 2 join; Join with MCU circuit 40 after described bleeder circuit 30 dividing potential drops; Full-bridge output circuit 50 joins with the positive pole of filter capacitor 2;

Described bleeder circuit 30 is to be composed in series by two resistance, and its tie point and MCU circuit 40 join.

The utility model has saved current sensor compared with prior art, has increased the bleeder circuit of dc bus accordingly, and this needs resistance is formed.When short circuit took place, DC bus-bar voltage directly reflected voltage fluctuation, and voltage fluctuation signal is directly sent into the MCU circuit and carried out judgment processing after the bleeder circuit dividing potential drop.

When full-bridge output is short-circuited, certainly will cause the fluctuation of dc bus, the bleeder circuit fluctuation that is about to dc bus is at this moment carried out dividing potential drop and is sent into the judgement that further DC bus-bar voltage fluctuation is done in the MCU unit, confirms whether full-bridge output is short-circuited.

The utility model has directly reacted the variation that direct current bus bar is pressed, and it is accurate that reaction is in time judged, and reduced the transform part in the loop, reduced cost, increased short circuits.

Claims

1. short-circuit protection circuit in the inverter, comprising: full-bridge rectification (1) and filter capacitor (2) are rectified into high direct voltage with ac high-voltage; It is characterized in that: also comprise a bleeder circuit (30); Two ends of two ends of described bleeder circuit (30) and filter capacitor (2) join; Join with MCU circuit (40) after described bleeder circuit (30) dividing potential drop; Full-bridge output circuit (50) joins with the positive pole of filter capacitor (2).

2. short-circuit protection circuit in the inverter according to claim 1 is characterized in that: described bleeder circuit (30) is to be composed in series by two resistance, and its tie point and MCU circuit (40) join.