Zero-crossing detection circuit, pfc circuit and two interleaved parallel pfc circuits

A zero-crossing detection circuit and zero-crossing signal technology, applied in the measurement of current/voltage, measurement of electrical variables, high-efficiency power electronic conversion, etc., can solve the problems of large negative current in the circuit, reducing the reliability of the corresponding system, and low bandwidth Achieve the effect of reducing negative current, compensating distortion and reducing input current harmonics

Active Publication Date: 2021-11-05
HANGZHOU ZHONGHEN ELECTRIC CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the above methods usually have problems such as low bandwidth, which causes the detected zero-crossing to deviate from the real zero-crossing, resulting in a large negative current in the switched circuit, thereby reducing the reliability of the corresponding system

Method used

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  • Zero-crossing detection circuit, pfc circuit and two interleaved parallel pfc circuits
  • Zero-crossing detection circuit, pfc circuit and two interleaved parallel pfc circuits
  • Zero-crossing detection circuit, pfc circuit and two interleaved parallel pfc circuits

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] This embodiment provides a zero-crossing detection circuit, aiming to solve the problem of "it is difficult to accurately determine the zero-crossing for a circuit with freewheeling components". Specifically, refer to figure 1 As shown, the zero-crossing detection circuit 10 includes a current transformer CT, a main switching tube Q1 and a negative current regulation circuit 101 .

[0040]The current transformer CT includes a primary winding and a secondary winding. The primary winding and the main switching tube Q1 are connected in series to form a first converter, and the first converter is cooperatively connected to an AC source. The primary winding has a terminal with the same name and a terminal with the same name. Here, the current flowing from the non-identical terminal of the primary winding to the terminal with the same name is recorded as the forward current of the zero-crossing detection circuit. Otherwise, the current flows from the terminal with the same na...

Embodiment 2

[0051] This embodiment provides a zero-crossing detection circuit, and this embodiment is implemented on the basis of Embodiment 1.

[0052] refer to figure 1 and figure 2 As shown, the comparison unit 1011 may include a comparison switch Q2 and a second resistor R2. Wherein, the first terminal A1 is connected to the DC source, the third resistor R3 is connected in series between the second terminal A2 and the positive terminal of the comparison switch Q2, and the second resistor R2 is connected in series between the ground and the negative terminal of the comparison switch Q2 During this period, the base of the comparison switch Q2 is connected to the negative terminal or grounded through the fifth resistor, and the base of the comparison switch Q2 is connected to the trigger unit 1012 .

[0053] The comparison switch Q2 can be any one of SI MOSFET, IGBT, GaN MOSFET, SIC MOSFET, triode, thyristor and relay, or a bidirectional switch formed by a combination thereof. It is ...

Embodiment 3

[0066] This embodiment provides a PFC circuit with zero-crossing detection, refer to Figure 7 As shown, it includes the zero-crossing detection circuit 10 in Embodiment 1 and / or Embodiment 2 above. Specifically, the PFC circuit with zero-crossing detection includes an AC source, a first diode D1 , a second diode D2 , a first inductor L1 , a capacitor C, a load Rx and two sets of zero-crossing detection circuits 10 . The two groups of zero-crossing detection circuits 10 are respectively denoted as a first zero-crossing detection circuit and a second zero-crossing detection circuit.

[0067] One end of the first inductor L1 is connected to the positive pole of the AC source, and the other end is marked as the connection terminal f. The anode of the first diode D1 and the cathode of the second diode D2 are both connected to the negative pole of the AC source. The detection circuit is cooperatively connected between the connection terminal f and the cathode of the first diode D1...

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PUM

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Abstract

The invention discloses a zero-crossing detection circuit, which relates to the technical field of zero-crossing detection, and includes a current transformer, a main switch tube and a negative current regulating circuit; The tubes are connected in series to form a first converter, and the first converter is connected to the AC source; the negative current regulating circuit includes a first resistor, a third resistor, a comparison unit, a trigger unit and a DC source; when the first converter flows through the negative When the value of the negative current and the negative current is equal to the preset threshold, the induced current generated by the secondary winding flows into the comparison unit through the second terminal, the first resistor and the third resistor, so that the trigger unit outputs a zero-crossing signal, and the main switch tube responds zero-crossing signal and shutdown. The invention also discloses a PFC circuit with zero-crossing detection and two staggered parallel PFC circuits. The present invention outputs a zero-crossing signal to turn off the corresponding main switch tube when the zero-crossing occurs, so as to improve the reliability of the result and the system efficiency.

Description

technical field [0001] The invention relates to the technical field of zero-crossing detection, in particular to a zero-crossing detection circuit, a PFC circuit and two interleaved parallel PFC circuits. Background technique [0002] Zero-crossing detection refers to: in the power system, the waveform changes from positive half cycle to negative half cycle or negative half cycle to positive half cycle. switch. [0003] Existing zero-crossing detection usually adopts methods such as optocoupler isolation or Hall sensor. However, the above-mentioned method usually has problems such as low bandwidth, which causes the detected zero-crossing to deviate from the real zero-crossing, so that there is a large negative current in the switched circuit, thereby reducing the reliability of the corresponding system. Contents of the invention [0004] In order to overcome the deficiencies of the prior art, one of the objects of the present invention is to provide a zero-crossing detec...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H02M1/08H02M1/088H02M3/158H02M1/42H02M1/12G01R19/175
CPCH02M1/083H02M1/088H02M3/1584H02M1/4208H02M1/12G01R19/175H02M1/0009H02M1/0058H02M3/1586Y02B70/10
Inventor 韦康朱益波刘宏森郑煦
Owner HANGZHOU ZHONGHEN ELECTRIC CO LTD
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