Simple three-phase slow power-on circuit

Abstract

The utility model provides a simple three-phase slow power-on circuit, which comprises a three-phase power supply circuit, an inductor and a resistor are connected in series on the three-phase power supply circuit, the three-phase power supply circuit is respectively connected with a power supply input end and a power supply output end, the power supply output end is connected with a transformer, a change-over switch is arranged on the circuit, and the change-over switch and the resistor are connected in parallel.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic circuit design technical field, concretely is a simple three -phase slow -on circuit. BACKGROUND

[0002] The slow-on circuit is a common method for preventing the surge phenomenon caused by power input in modern power supply systems, and is widely used in the field of slow-start related circuits in modern power supply systems. In a switching power supply with three-phase alternating current input, the surge phenomenon is extremely frequent during the starting process, and causes great damage to internal components of the power supply. Therefore, suppressing the surge phenomenon is an important concern for three-phase alternating current input power supplies. Adding a slow-start circuit to the power supply is an important method to avoid the surge phenomenon. Therefore, a high-reliability three-phase alternating current input slow-on circuit is needed to ensure that the three-phase alternating current input power supply starts without a surge phenomenon and can start smoothly.

[0003] The utility model with patent No. CN218850400U discloses a kind of applicable to high-power inductive equipment power-on automatic slow-start circuit device, and the size of power flow in circuit is limited by converting electric energy into heat energy and dissipating by power resistor. However, the above-mentioned scheme is implemented, and energy loss is easily caused, and the utilization rate of electric energy is low. Therefore, a simple three-phase slow-on circuit is proposed to solve the above-mentioned problems. UTILITY MODEL CONTENT

[0004] In view of the deficiencies of the prior art, the utility model provides a simple three-phase slow-on circuit, which has the function of slow-on, and solves the technical problem that the load device needs power supply when power-on, which easily causes damage to the device.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical scheme:

[0006] A simple three-phase slow-on circuit includes a three-phase power supply circuit, an inductor and a resistor connected in series on the three-phase power supply circuit, a power input end and a power output end connected to the three-phase power supply circuit respectively, a transformer connected to the power output end, a switching switch provided on the circuit, and the switching switch and the resistor connected in parallel.

[0007] Further, the switching switch is a contactor, and a delay relay is connected to the switching switch to control the delay switching of the switching switch.

[0008] Further, a power supply branch one is connected to the three-phase power supply circuit, a power supply branch two is connected in parallel to the power supply branch one, the delay relay is provided on the power supply branch one, the contactor is provided on the power supply branch two, and the delay relay realizes the switching of the contactor by controlling the on-off of the power supply branch two.

[0009] Further, a circuit breaker two is provided on the power supply branch one.

[0010] Further, the capacitor is connected in series between the inductor and the transformer.

[0011] Further, the power input end is provided with a breaker one.

[0012] Compared with the prior art, the technical scheme of the application has the following beneficial effects:

[0013] The simple three-phase slow power-on circuit has the following advantages: in the initial state, the resistance and the inductor are connected in series on the three-phase power supply circuit; by arranging a delay switch circuit on the three-phase power supply circuit, the resistance is connected in short circuit on the three-phase power supply circuit, so that the impedance of the current on the three-phase power supply circuit is adjusted; in the later period, the resistance does not need to output power on the three-phase power supply circuit, the overall circuit power is extremely low, and the waste of energy is avoided; meanwhile, the delay switch power supply circuit is directly powered by the three-phase power supply circuit, the circuit structure is simple, and the use is convenient. BRIEF DESCRIPTION OF DRAWINGS

[0014] Fig. 1 It is the circuit principle diagram of the inverter power supply output circuit of the utility model;

[0015] Fig. 2 It is the output slow power-on circuit principle diagram in the utility model example. DETAILED DESCRIPTION

[0016] The technical scheme in the embodiments of the utility model will be clearly and completely described in combination with the drawings in the embodiments of the utility model.

[0017] Please refer to Figs. 1-2 The simple three-phase slow power-on circuit in the embodiment includes a three-phase power supply circuit, the inductor and the resistance are connected in series on the three-phase power supply circuit, the three-phase power supply circuit is connected with a power input end and a power output end respectively, the power output end is connected with a transformer, and the circuit is characterized in that: a switch is arranged on the circuit, and the switch and the resistance are connected in parallel. When the switch is turned off, the resistance and the inductor are connected in series on the three-phase power supply circuit, and when the switch is turned on, the resistance is short-circuited, and only the inductor is connected with the three-phase power supply circuit. The resistance and the inductor are connected in series through the delay, the current impedance of the three-phase power supply circuit is adjusted, the transformer is beneficial to stably improving the output power, the three-phase alternating current input slow power-on is realized, the starting of the three-phase alternating current input power supply without the phenomenon of inrush current is ensured, and the starting is smooth.

[0018] The switch is a contactor KM1, and a delay relay Q1 for controlling the delay switching of the switch is connected to the switch. Specifically, a power supply branch one is connected to the three-phase power supply circuit, the power supply branch one is connected in parallel with a power supply branch two, the delay relay Q1 is arranged on the power supply branch one, and the contactor KM1 is arranged on the power supply branch two.

[0019] In the application, the time delay relay Q1 realizes the switching of the contactor KM1 by controlling the on-off of the power supply branch two. The working principle is as follows: when the power supply branch one is powered on, the time delay relay Q1 coil is powered on, and after a delay, the time delay relay contact Q1 is closed, the power supply branch two is turned on, the contactor KM1 coil is powered on, the contactor KM1 is closed, and the resistance is short-circuited. Conversely, the power supply branch one is powered off, the relay contact Q1 disconnects the power supply branch two, and the contactor KM1 is disconnected. The resistance and inductance are connected in series on the three-phase power supply circuit.

[0020] In the application, the time delay relay Q1 is set according to the circuit of the finished product power supply to be built in the adjustable range, which is suitable for different power supply circuits and meets the demand of increasing input or output slow power-on function of the finished product power supply.

[0021] In the application, a capacitor is connected in series between the inductor and the transformer. A capacitor is connected in series between the inductor and the transformer. Capacitors are connected in series on the three cables of the three-phase power supply circuit, and the capacitors are used for filtering, which is beneficial to the smoothness and stability of the three-phase power supply circuit power output.

[0022] In the application, a circuit breaker one QFI is arranged at the power supply input end. A circuit breaker two OF is arranged on the power supply branch one. The circuit breaker one QFI and the circuit breaker two OF are used for power-off protection.

[0023] Working principle: the equivalent impedance of the resistance and the inductor in series is the vector sum of the resistance value and the inductive reactance. The equivalent impedance of the resistance and the inductor in series hinders the current of the three-phase power supply circuit, realizing the gradual increase of the current of the three-phase power supply circuit. By changing the size of the resistance in the three-phase power supply circuit, the equivalent impedance is adjusted, so as to realize the adjustment of the current impedance on the three-phase power supply circuit. In the application, in the initial state, the resistance and the inductor are connected in series on the three-phase power supply circuit. By setting a time delay switch circuit on the three-phase power supply circuit, the resistance is connected in short circuit on the three-phase power supply circuit, so as to realize the adjustment of the current impedance on the three-phase power supply circuit.

[0024] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the utility model, and the scope of the utility model is defined by the appended claims and their equivalents.

Claims

1. A simple three-phase soft-on circuit, comprising a three-phase power supply circuit, wherein an inductor and a resistor are connected in series in the three-phase power supply circuit, the three-phase power supply circuit is respectively connected to a power input terminal and a power output terminal, and a transformer is connected to the power output terminal, characterized in that: The circuit is provided with a switch, which is connected with the resistor in parallel.

2. A simple three-phase soft power-on circuit according to claim 1, characterized in that: The switch is a contactor (KM1), and a time-delay relay (Q1) is connected to the switch to control the time-delay switching of the switch.

3. A simple three-phase soft power-on circuit according to claim 2, characterized in that: The three-phase power supply circuit is connected with a power supply branch one, the power supply branch one is connected with a power supply branch two in parallel, the time-delay relay (Q1) is arranged on the power supply branch one, the contactor (KM1) is arranged on the power supply branch two, and the time-delay relay (Q1) realizes the switch switching of the contactor (KM1) by controlling the on-off of the power supply branch two.

4. A simple three-phase soft power-on circuit according to claim 3, characterized in that: The power supply branch one is provided with a circuit breaker two (OF).

5. The simple three-phase soft power-on circuit according to claim 1, characterized in that: The inductor is connected with the transformer in series, and the capacitor is connected in series between the inductor and the transformer.

6. A simple three phase soft start-up circuit as claimed in claim 1, wherein: The power supply input end is provided with a circuit breaker one (QFI).

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