CN210273828U

CN210273828U - Zero-crossing soft start circuit

Info

Publication number: CN210273828U
Application number: CN201921188844.8U
Authority: CN
Inventors: 卢悦; 丁仕彬
Original assignee: Jiangsu Laity Electrical Co ltd
Current assignee: Jiangsu Laity Electrical Co ltd
Priority date: 2019-07-26
Filing date: 2019-07-26
Publication date: 2020-04-07
Anticipated expiration: 2029-07-26

Abstract

The utility model provides a zero crossing soft start circuit, include: the photoelectric coupling controller U1, the controlled silicon Q1, the resistor R2 and the resistor R4, wherein the signal input end of the photoelectric coupling controller U1 is connected with the COM end and the KA end and receives a trigger signal; the signal output end of the photoelectric coupling controller U1 is connected with the resistor R2 and the resistor R4 in series, the input end and the output end of the controlled silicon Q1 are respectively connected with the other end of the resistor R2 and the other end of the resistor R4, and the circuit is small in charging differential pressure, low in charging current, free of impact on a power grid, simple in circuit, free of extra control signals and convenient to maintain.

Description

Zero-crossing soft start circuit

Technical Field

The utility model relates to a silicon controlled rectifier zero passage soft start circuit field especially relates to zero passage soft start circuit.

Background

The APF, the SVG, the frequency converter and other devices can charge the direct current side energy storage filter capacitor when starting, but the starting has randomness, if the devices are started at the peak value of the alternating current, when the direct current side capacitor is charged (the capacitor is equivalent to a short circuit state in the moment of electrifying), a very large starting current can be generated, and the impact current can cause the device to jump and break down, or even has a large impact on the power grid.

The mode that the mode was used always at present mainly is the low resistance of series connection, powerful starting resistor's mode, treat that the direct current side charges certain voltage rethread relay with the resistance bypass, this kind of mode is simple relatively, but can produce great loss on the in-process at the start-up on resistance, if the resistance of chooseing for use is too big can let the relay in the actuation in the twinkling of an eye because the existence of resistance both ends pressure drop, lead to the relay inefficacy, the effect of current-limiting is then not reached to the resistance undersize, can burn out the resistance even, general powerful starting resistor volume is also bigger.

SUMMERY OF THE UTILITY MODEL

The utility model provides a zero crossing soft start circuit, include: the photoelectric coupling controller U1, the controlled silicon Q1, the resistor R2 and the resistor R4, wherein the signal input end of the photoelectric coupling controller U1 is connected with the COM end and the KA end and receives a trigger signal; the signal output end of the photoelectric coupling controller U1 is connected in series with the resistor R2 and the resistor R4, and the input end and the output end of the controllable silicon Q1 are respectively connected with the other end of the resistor R2 and the other end of the resistor R4.

Preferably, the photoelectric coupling controller U1 is MOC 3081M.

Preferably, the 1 pin of the MOC3081M is connected to the COM terminal, and the 2 pin is connected to the KA terminal, for receiving the trigger signal.

Preferably, a pin 6 of the MOC3081M is connected with a G pole of a resistor R2 and a controllable silicon Q1, and the other end of the resistor R2 is connected with a K pole of a controllable silicon Q1; the 4 pins of the MOC3081M are connected with a resistor R4, and the other end of the resistor R4 is connected with the A pole of a thyristor Q1.

Preferably, a resistor R3 is connected between the 4 pin and the 6 pin of the MOC3081M, and the protection effect is turned off.

Preferably, the device further comprises a diode D1, wherein the anode of the diode D1 is connected with the COM terminal, and the cathode of the diode D1 is connected with the 1 pin of the MOC30 3081M U1.

Preferably, the circuit further comprises a resistor R1, and two ends of the resistor R1 are respectively connected to the KA terminal and 2 pins of the MOC30 3081M U1.

Preferably, the device further comprises a diode D2, wherein the anode of the diode D2 is connected with the 6 pin of the MOC3081M U1, and the cathode of the diode D2 is connected with the G pole of the controllable silicon Q1.

Preferably, the system further comprises a diode D3, wherein the anode of the diode D3 is connected with the K pole of the thyristor Q1, and the cathode is connected with the G pole of the thyristor Q1.

The utility model has the advantages that: the circuit has the advantages of small charging differential pressure, low charging current, no impact on a power grid, simple circuit, no need of additional control signals and convenient maintenance.

Drawings

Fig. 1 is a schematic circuit diagram of the present invention;

FIG. 2 is a pin circuit diagram of MOC 3081M;

fig. 3 is a schematic diagram showing the transition of the zero crossing point along with the rise of the voltage on the dc side in the charging process.

Detailed Description

The photoelectric coupling controller MOC3081M with zero-cross detection shown in fig. 2 can also be other photoelectric coupling controllers with zero-cross detection, and the typical detection zero-cross voltage range is 12V, which ensures that the circuit can be switched on only when the voltage difference on the ac/dc side is very small, i.e. when the voltage between pin 4 and pin 6 is less than 12V and the control voltage is present between pin 1 and pin 2, the circuit is switched on; when the voltage exceeds the voltage range, the circuit cannot be switched on even if control voltage exists between

pins

1 and 2; if a larger conduction pressure difference range is required, a plurality of MOCs 3081M can be connected in series, and the detected pressure difference range is 12N (N is the number of devices in series).

Taking 230v alternating current as an example, as shown in fig. 1, the utility model comprises: the signal input end of the photoelectric coupling controller U1 is connected with a COM end and a KA end and receives a trigger signal, the COM end is a positive pole of the trigger signal, and the KA is a negative pole of the trigger signal; the signal output end of a photoelectric coupling controller U1, a resistor R2 and a resistor R4 form a series circuit, a controlled silicon Q1 is a unidirectional controlled silicon, an input end K2 and an output end K1 of the controlled silicon Q1 are respectively connected to the other end of the resistor R2 and the other end of the resistor R4, G-K2 is a driving pin of the controlled silicon, the turn-on voltage (VG-K2) of the Q1 is the voltage on the resistor R2, and the resistance value of the resistor R4 can be adjusted according to actual needs to obtain an ideal driving voltage value.

Preferably, the photoelectric coupling controller U1 is MOC 3081M.

Fig. 3 is a schematic diagram illustrating a transition of a zero crossing point along with a rise of a dc-side voltage in a charging process, where a curve is an ac voltage, an oblique line is a dc-side voltage, the charging process only occurs when the ac voltage is greater than the dc voltage, and a voltage difference between the ac voltage and the dc voltage is not greater than 12V (or a preset allowable charging voltage difference), and as a charging period progresses, the dc-side voltage at a rectified end rises, and a zero crossing point detected by U1 also shifts, until the zero crossing point reaches a value near a peak of the ac voltage, and charging is completed.

The zero-crossing soft start circuit can turn on the charging circuit when the voltage difference of the alternating current and direct current sides (the voltage of the alternating current sides minus the voltage of the direct current sides) is low, and the charging circuit is turned off when the voltage difference exceeds a certain range, and the steps are repeated, and the voltage of the direct current sides is charged to the maximum value after a plurality of cycles.

The circuit has the advantages of small charging differential pressure, low charging current, no impact on a power grid, simple circuit, no need of additional control signals and convenient maintenance.

The above-described embodiments are merely illustrative of the principles and utilities of the present patent application and are not intended to limit the present patent application. Modifications and variations can be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of this patent application. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical concepts disclosed in the present application shall be covered by the claims of this patent application.

Claims

1. Zero crossing soft start circuit, its characterized in that: the method comprises the following steps: the photoelectric coupling controller U1, the controlled silicon Q1, the resistor R2 and the resistor R4, wherein the signal input end of the photoelectric coupling controller U1 is connected with the COM end and the KA end and receives a trigger signal; the signal output end of the photoelectric coupling controller U1 is connected in series with the resistor R2 and the resistor R4, and the input end and the output end of the controllable silicon Q1 are respectively connected with the other end of the resistor R2 and the other end of the resistor R4.

2. A zero-crossing soft start circuit as claimed in claim 1, wherein: the photoelectric coupling controller U1 selects MOC 3081M.

3. A zero-crossing soft start circuit as claimed in claim 2, wherein: the 1 pin of the MOC3081M is connected to the COM terminal, and the 2 pin is connected to the KA terminal, and is used for receiving the trigger signal.

4. A zero-crossing soft start circuit as claimed in claim 2, wherein: the pin 6 of the MOC3081M is connected with the G pole of a resistor R2 and a thyristor Q1, and the other end of the resistor R2 is connected with the K pole of a thyristor Q1; the 4 pins of the MOC3081M are connected with a resistor R4, and the other end of the resistor R4 is connected with the A pole of a thyristor Q1.

5. A zero-crossing soft start circuit as claimed in claim 4, wherein: and a resistor R3 is connected between the 4 pin and the 6 pin of the MOC3081M, so that the protection effect is turned off.

6. A zero-crossing soft start circuit as claimed in claim 2, wherein: the diode D1 is also included, the anode of the diode D1 is connected with the COM end, and the cathode is connected with the 1 pin of the MOC3081M U1.

7. A zero-crossing soft start circuit as claimed in claim 2, wherein: the circuit also comprises a resistor R1, wherein two ends of the resistor R1 are respectively connected with the KA terminal and 2 pins of the MOC3081M U1.

8. A zero-crossing soft start circuit as claimed in claim 4, wherein: the high-voltage power supply further comprises a diode D2, wherein the anode of the diode D2 is connected with the 6 pins of the MOC30 3081M U1, and the cathode of the diode D2 is connected with the G pole of the controllable silicon Q1.

9. A zero-crossing soft start circuit as claimed in claim 2, wherein: the thyristor Q1 further comprises a diode D3, wherein the anode of the diode D3 is connected with the K pole of the thyristor Q1, and the cathode of the diode D3 is connected with the G pole of the thyristor Q1.