CN219627571U

CN219627571U - AC voltage regulating control hot-press welding power supply with resonant cavity

Info

Publication number: CN219627571U
Application number: CN202320017319.XU
Authority: CN
Inventors: 冬雷; 郝颖; 郭志强; 于瑞祺; 温昊东
Original assignee: Tangshan Research Institute Of Beijing University Of Technology
Current assignee: Tangshan Research Institute Of Beijing University Of Technology
Priority date: 2023-01-05
Filing date: 2023-01-05
Publication date: 2023-09-01
Anticipated expiration: 2033-01-05

Abstract

An alternating current voltage regulation control hot-press welding power supply with a resonant cavity comprises a temperature controller, an auxiliary power supply, a power switch, a resonant unit, a current sensor, a voltage regulation switch and a transformer; the alternating current L and N ends are connected with the power switch, the resonance unit and the transformer in series to form a resonance cavity for series resonance; the current sensor is connected with the voltage regulating switch and the transformer in series, and the voltage regulating switch is connected with a plurality of middle taps of the transformer; the secondary side of the transformer is connected with a heating head, and a temperature sensor is arranged on the heating head; the temperature sensor, the current sensor and the power switch are all connected with the temperature controller; the input end of the auxiliary power supply is connected with the mains supply, and the output end of the auxiliary power supply is connected with the temperature controller and supplies power for the temperature controller. The utility model adopts the bidirectional thyristor phase-shift control main circuit topology, thereby reducing the hardware cost of the system; the resonant cavity structure is adopted, so that the harmonic content of primary side current of the transformer is reduced, and the power factor of the system is improved; the eddy current loss of the transformer is reduced, the heating is reduced, the system efficiency is improved, and the use cost is reduced.

Description

AC voltage regulating control hot-press welding power supply with resonant cavity

Technical Field

The utility model relates to the technical field of power supplies, in particular to an alternating current voltage regulation control hot-press welding power supply with a resonant cavity.

Background

Current welding power sources, including hot-press welding power sources, use high frequency inverter circuit topologies in many cases. The high-frequency inverter power supply has the characteristics of quick response, high precision and the like, but the high-frequency inverter topology also has the characteristics of complex structure, higher cost, easiness in failure, poor overload capacity and the like. The hot press welding process has low precision, and the temperature of the hot press welding head is a large inertial load, so that the control power supply does not need to have excessively high response speed, and the control period of once adjustment every 10ms can completely meet the temperature control performance by utilizing 50Hz commercial power. Therefore, a thyristor alternating current voltage regulation control mode can be adopted in practical application. However, since the thyristor AC voltage regulation is phase-shifting control, a large amount of current harmonic waves can be generated, the power factor of a power supply is reduced, and the high-frequency harmonic wave current can cause eddy current loss of a transformer, reduce the system efficiency and seriously heat the transformer.

In summary, in the prior art, the high-frequency inverter power supply adopts a high-speed power device, and has the advantages of complex structure, high cost and easy damage; the thyristor AC voltage regulating power supply has larger harmonic wave, can pollute the power grid, and has low power factor, low efficiency and serious heating.

Disclosure of Invention

Aiming at the defects existing in the prior art, the utility model provides an alternating current voltage regulation control hot-press welding power supply with a resonant cavity, which simplifies the topology of a main circuit, improves the power factor of the power supply, reduces the harmonic current content and reduces the heating of the power supply.

The technical scheme adopted by the utility model is that the intelligent control system comprises a temperature controller, an auxiliary power supply, a power switch, a resonance unit, a current sensor, a voltage regulating switch and a transformer; the alternating current L and N ends are connected with the power switch, the resonance unit and the transformer in series to form a resonance cavity for series resonance; the current sensor is connected with a voltage regulating switch and a transformer in series, and the voltage regulating switch is connected with a plurality of middle taps of the transformer; the secondary side of the transformer is connected with a heating head, and a temperature sensor is arranged on the heating head; the temperature sensor, the current sensor and the power switch are all connected with the temperature controller; the input end of the auxiliary power supply is connected with the mains supply, and the output end of the auxiliary power supply is connected with the temperature controller and supplies power for the temperature controller.

Preferably, the resonance unit comprises a resonance inductor and a resonance capacitor;

preferably, the power switch is a bidirectional thyristor, comprising a first thyristor and a second thyristor; the first thyristor is connected in anti-parallel with the second thyristor, and the gates thereof are also connected together.

Preferably, the auxiliary power supply converts the mains supply into direct current of different voltage levels and is responsible for the power supply of the whole control system.

Preferably, the voltage regulating switch comprises N (N is more than 2) voltage regulating switches, the temperature controller is controlled by a relay, one end of the voltage regulating switch is connected with the current sensor, and the other end of the voltage regulating switch is connected with a primary side center tap of the transformer.

Preferably, the temperature controller comprises a CPU, a driving module, a current acquisition module, a temperature acquisition module, a communication module and a zero crossing detection module; the CPU is connected with other modules and is used for collecting control signals and outputting control quantity; the driving module is connected with the gate electrode of the power switch, the current acquisition module is connected with the current sensor, and the temperature acquisition module is connected with the temperature sensor; the zero-crossing detection module is connected with the auxiliary power supply.

Compared with the prior art, the technical scheme provided by the utility model has the following advantages and beneficial effects:

the utility model has the advantages that the bidirectional thyristor phase-shift control main circuit topology is adopted, and the hardware cost of the system is reduced.

The utility model has the advantages that the resonant cavity structure is adopted, the harmonic content of the primary side current of the transformer is reduced, and the power factor of the system is improved.

The utility model has the advantages that the higher harmonic wave of the input current of the transformer is reduced through series resonance, thereby reducing the eddy current loss of the transformer, reducing the heating, improving the system efficiency and reducing the use cost.

Drawings

FIG. 1 is a schematic diagram of the overall structure of an AC voltage regulation control hot-press welding power supply with a resonant cavity according to the present utility model;

FIG. 2 is a schematic diagram of a resonant cavity in accordance with the present utility model;

FIG. 3 is a schematic diagram of a triac power switch in accordance with the present utility model;

FIG. 4 is a schematic diagram of an anti-parallel thyristor power switch in the utility model;

FIG. 5 is a schematic diagram of a voltage regulating switch in the utility model;

FIG. 6 is a schematic diagram of the structure of the thermostat of the utility model;

FIG. 7 is a schematic diagram of the circuit configuration of the utility model;

FIG. 8 is a schematic diagram of a non-resonant cavity simulation model;

FIG. 9 is a schematic diagram of the primary current waveform of a non-resonant cavity simulated transformer;

FIG. 10 is a schematic diagram of primary current harmonics of a non-resonant cavity simulated transformer in an embodiment;

FIG. 11 is a schematic diagram of a simulation model of an utility model including a resonant cavity;

FIG. 12 is a schematic diagram of a primary current waveform of a simulated transformer with a resonant cavity according to an embodiment of the utility model;

FIG. 13 is a schematic diagram of primary current harmonics of a simulated transformer with a resonant cavity according to an embodiment of the utility model;

wherein: 1, a temperature controller; 101, CPU;102, a driving module; 103, a current collection module; 104, a temperature acquisition module; 105, a communication module; 106, a zero-crossing detection module; 2, a power switch; 201, a first thyristor; 202, a second thyristor; 3, a resonance unit; 301, resonant inductance; 302, a resonant capacitance; 4, a voltage regulating switch; 401, a first voltage regulating switch; 402, a second voltage regulating switch; 403, nth voltage regulating switch; 5, a transformer; 6, heating the head; 7, a temperature sensor; 8, an auxiliary power supply; and 9, a current sensor.

Detailed Description

The utility model is further described below with reference to the accompanying drawings.

The utility model relates to an alternating current voltage regulation control hot-press welding power supply, in particular to an alternating current voltage regulation control hot-press welding power supply with a resonant cavity.

As shown in fig. 1, an ac voltage-regulating control hot-press welding power supply with a resonant cavity includes a temperature controller 1 and electronic components in an ac power supply circuit, and mainly includes a power switch 2, a resonant unit 3, a current sensor 9, a voltage-regulating switch 4, a transformer 5 and an auxiliary power supply 8.

The alternating current L and N ends are connected with the power switch 2, the resonance unit 3 and the transformer 5 in series to form a resonance cavity.

The current sensor 9 is connected with the voltage regulating switch 4 and the transformer 5 in series to detect the primary side current of the transformer 5.

The secondary side of the transformer 5 is connected with a heating head 6 for welding, and a temperature sensor 7 is arranged on the heating head 6 and used for detecting the temperature of the heating head 6.

The temperature controller 1 is connected with a current sensor 9 and a temperature sensor 7 and is used for detecting the primary side current of the transformer 5 and the temperature of the heating head 6, and the temperature of the heating head 6 is controlled by calculating the phase-shifting control angle of the output power switch 2.

Fig. 2 is a schematic diagram of a resonant cavity composition, wherein the resonant unit 3 includes a resonant inductor 301 and a resonant capacitor 302. The ac power supply forms a series resonant cavity through the power switch 2, the resonant inductor 301, the resonant capacitor 302, and the primary side of the transformer 5. By setting the parameters of the resonant inductor 301 and the resonant capacitor 302, the series resonant frequency is made the same as the ac power supply frequency, preferably 50Hz. When the power switch 2 is phase-shifted, the excitation resonant cavity resonates in series, so that the current in the series loop approximates a sine wave. The content of higher harmonics in the current can be greatly reduced.

As shown in fig. 3, the power switch 2 is preferably a triac, the triac is driven by a current pulse, and a current pulse is applied to the gate g terminal at a proper voltage phase angle moment, so that the turn-on of the triac can be controlled, and the current zero crossing moment is cut off. The bidirectional thyristor can control the bidirectional flow of current, so that the controlled object can be controlled twice in each power frequency period.

Further, as shown in fig. 4, the power switch 2 is formed by reversely connecting a first thyristor 201 and a second thyristor 202 in parallel, and the gates g thereof are also connected together, so as to control the bidirectional conduction of current in the same manner as the bidirectional thyristor.

Compared with an anti-parallel thyristor power switch, the bidirectional thyristor phase-shift control main circuit topology is adopted, and the hardware cost of the system is reduced more favorably.

Fig. 5 is a schematic diagram of voltage regulating switches, the voltage regulating switch 4 includes N (N > 2) voltage regulating switches, the on-off of each voltage regulating switch can be controlled by the temperature controller 1 through a relay, one end of the first voltage regulating switch 401, one end of the second voltage regulating switch 402 and one end of the nth voltage regulating switch 403 are connected with the current sensor 9 together and are connected to the L1 end of the ac power supply, and the other end is connected with the primary side center tap of the transformer 5 respectively. The number of turns of the primary side of the transformer 5 can be changed each time a voltage regulating switch is turned on, thereby changing the transformation ratio and the output voltage of the transformer.

As an example, as shown in fig. 6, the thermostat 1 includes: the device comprises a CPU101, a driving module 102, a current acquisition module 103, a temperature acquisition module 104, a communication module 105 and a zero crossing detection module 106.

The CPU101 is connected with other modules, collects signals of the sensors, outputs control quantity after calculation, and communicates with other devices or upper computers through the communication module 105 to exchange information.

The driving module 102 is connected with the gate g of the power switch 2, and outputs a phase shift trigger signal according to calculation of the CPU101 to generate current pulses to drive the power switch 2 to be turned on.

The current acquisition module 103 is connected with the current sensor 9 and acquires the primary side current of the transformer 5, and the CPU101 realizes current loop control according to the acquired primary side current of the transformer 5.

The temperature acquisition module 104 is connected with the temperature sensor 7, acquires the temperature on the heating head 6, and the CPU101 realizes temperature closed-loop control according to the acquired temperature signal and a set temperature value or a set temperature curve.

The communication module 105 is connected with other devices or an upper computer, and the upper computer or other external devices give out temperature control instructions and transmit internal parameters of the hot-press welding power supply to the upper computer or other devices.

As an example, as shown in fig. 7, the input end of the auxiliary power supply 8 is connected to two ends of the ac power supply L, N, and the dc power with different voltage levels generated by the auxiliary power supply 8 is respectively supplied to each module in the temperature controller 1. In addition, the auxiliary power supply inputs an alternating voltage signal to the zero-crossing detection module 106 after being isolated, is used for detecting the phase of the input alternating voltage, and after the CPU101 calculates a phase-shift control angle, the auxiliary power supply outputs a driving current pulse to the gate electrode g of the power switch 2 through the driving module after time delay according to the zero-crossing signal of the alternating voltage, and is used for controlling the conduction of the power switch 2. After the power switch 2 is turned on, the alternating current power supply excites the resonant cavity formed by the resonant unit 3 to resonate, and electric energy is transmitted to the heating head 6 through the transformer.

The current sensor 9 detects the current of the resonant cavity, the temperature sensor 7 detects the temperature of the heating head 6, and the temperature is respectively transmitted to the temperature controller 1 to form current and temperature double closed-loop control. So that the temperature of the heating head 6 tracks a given heating temperature reference curve value.

After the alternating current input voltage subjected to phase shift control is subjected to resonance through the resonant cavity, an approximate sine wave current is generated, so that higher harmonic waves of the current input to the primary side of the transformer 5 are greatly reduced, the high-frequency eddy current loss of the transformer is reduced, the efficiency of the transformer is improved, the heating is reduced, the high-frequency noise of the transformer is reduced, the service life is prolonged, the reliability is improved, and the electromagnetic interference is reduced.

In order to demonstrate the effectiveness of the present utility model, computer simulations and experimental studies were performed, as shown in fig. 8-13.

Fig. 8 is a simplified model of a resonant cavity-less phase-shifting control power supply, by control, the primary current waveform of the transformer 5 when the phase-shifting control angle is 45 ° is shown in fig. 9. It can be seen that the primary current of the transformer 5 is not sinusoidal, but rather is shaved with a portion of the waveform, and there is a sudden current change. There are a large number of higher harmonics, the fast fourier decomposition waveform (FFT) of which is shown in fig. 10. The harmonic wave mainly contains odd harmonics, and the harmonic wave content is relatively rich. Harmonics up to 51 times and beyond are still significant.

Fig. 11 is a simulation model containing a resonant cavity, and the primary side current of the generated transformer 5 is shown in fig. 12 by adopting a 45-degree phase shift control angle. It can be seen that the primary current of the transformer 5 is closer to a sine wave, but has a little distortion at the zero crossing of the current due to the phase shift control, and no larger current abrupt change. As can be seen from fig. 13, the current harmonic wave of the primary side of the simulation transformer 5 with the resonant cavity is very small and can be ignored, so that the harmonic eddy current loss and noise of the transformer 5 can be greatly reduced.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the utility model, and therefore the utility model is not to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An alternating current voltage regulation control hot-press welding power supply with a resonant cavity is characterized by comprising a temperature controller (1), an auxiliary power supply (8), a power switch (2), a resonant unit (3), a current sensor (9), a voltage regulation switch (4) and a transformer (5);

the alternating current L and N ends are connected in series with the power switch (2), the resonance unit (3) and the transformer (5) to form a resonant cavity for series resonance;

the current sensor (9) is connected with the voltage regulating switch (4) and the transformer (5) in series; the voltage regulating switch (4) is connected with a plurality of middle taps of the transformer (5);

the secondary side of the transformer (5) is connected with a heating head (6), and a temperature sensor (7) is arranged on the heating head (6);

the temperature sensor (7), the current sensor (9) and the power switch (2) are all connected with the temperature controller (1); the input end of the auxiliary power supply (8) is connected with the mains supply, and the output end of the auxiliary power supply is connected with the temperature controller (1) and supplies power for the temperature controller.

2. An ac regulated voltage controlled hot-dip power supply with a resonant cavity according to claim 1, characterized in that the resonant unit (3) comprises a resonant inductance (301), a resonant capacitance (302).

3. An ac voltage regulating controlled hot-press welding power supply with a resonant cavity according to claim 1, characterized in that the power switch (2) is a triac.

4. An ac regulated voltage controlled hot-dip power supply with a resonant cavity according to claim 3, characterized in that the power switch (2) comprises a first thyristor (201) and a second thyristor (202); the first thyristor (201) is connected in anti-parallel with the second thyristor (202), and the gates thereof are also connected together.

5. An ac regulated pressure controlled hot welding power supply with a resonant cavity according to claim 1, characterized in that the auxiliary power supply (8) converts mains power into dc power of different voltage levels and is responsible for the power supply of the whole control system.

6. An ac voltage regulating control hot press welding power supply with a resonant cavity as claimed in claim 1, characterized in that the voltage regulating switch (4) comprises more than N (N > 2) voltage regulating switches, which are controlled by the temperature controller (1) through a relay, one end of the voltage regulating switch is connected with the current sensor (9), and the other end is connected with a primary side center tap of the transformer (5).

7. An ac voltage regulating controlled hot-press welding power supply with a resonant cavity according to claim 1, characterized in that the temperature controller (1) comprises a CPU (101), a driving module (102), a current collecting module (103), a temperature collecting module (104), a communication module (105) and a zero crossing detection module (106); the CPU (101) is respectively connected with the driving module (102), the current acquisition module (103), the temperature acquisition module (104), the communication module (105) and the zero crossing detection module (106) and is used for acquiring control signals and outputting control quantity; the driving module (102) is connected with the gate electrode of the power switch (2), the current acquisition module (103) is connected with the current sensor (9), and the temperature acquisition module (104) is connected with the temperature sensor (7); the zero-crossing detection module (106) is connected with the auxiliary power supply (8).