Crystal growth induction heating power supply with direct current standby input

Abstract

The utility model belongs to the field of medium-frequency induction heating power supplies, and particularly relates to a crystal growth induction heating power supply with direct-current standby input, which comprises a three-phase input circuit, a direct-current standby input circuit, a charging buffer circuit, a full-bridge inverter circuit and an output circuit. According to the utility model, a standby direct-current power supply channel is designed, the standby direct-current power supply can be automatically switched off, a safer power supply mode is provided for crystal growth equipment, and equipment output power fluctuation and shutdown faults caused by sudden flash or reduction of a three-phase power supply can be effectively avoided.

Description

Technical Field

[0001] The utility model relates to a crystal growth induction heating power supply with a DC standby input, which belongs to the field of medium frequency induction heating power supplies and is mainly used for power supply equipment for various crystal growths. Background Art

[0002] Induction heating power supply has the highest heating efficiency and the fastest speed for metal materials, and it is low-consumption and environmentally friendly. It has been widely used in various industries in the heat processing, heat treatment, hot assembly, welding, smelting and other processes of metal materials. Induction heating power supply consists of two parts, one is the AC power supply that provides energy, also known as variable frequency power supply; the other part is the induction coil that completes the electromagnetic induction energy conversion, called the inductor.

[0003] At present, conventional induction heating power supplies do not have a DC input backup power supply function. During the operation of the equipment, power grid fluctuations and flash interruptions often lead to unstable product quality or even scrapping of the products. Utility Model Content

[0004] The purpose of the utility model is to solve the technical problems existing in the background technology. To this end, a crystal growth induction heating power supply with a DC backup input is provided. After storing energy through the DC backup power supply, it can be directly connected to the DC end of the equipment after passing through a cut-off diode. When the power supply of the power grid is interrupted or fluctuates, the DC bus is automatically powered.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0006] A crystal growth induction heating power supply with a DC standby input, comprising a three-phase input circuit, a DC standby input circuit, a charging buffer circuit, a full-bridge inverter circuit and an output circuit;

[0007] The three-phase input circuit comprises a three-phase power supply, a circuit breaker and a three-phase rectifier bridge, wherein the three-phase electricity of the three-phase power supply is electrically connected to the three-phase input terminals of the three-phase rectifier bridge through the circuit breaker, and the rectifier output terminals DC+ and DC- of the three-phase rectifier bridge are electrically connected to the positive terminal and the negative terminal of the DC bus respectively;

[0008] The DC backup input circuit includes a DC backup power supply and a diode, wherein the V- terminal of the DC backup power supply is electrically connected to the negative terminal of the DC bus, the V+ terminal of the DC backup power supply is electrically connected to the anode of the diode, and the cathode of the diode is electrically connected to the positive terminal of the DC bus;

[0009] The positive end and the negative end of the DC bus are electrically connected to the charging buffer circuit and the full-bridge inverter circuit, and the output end of the full-bridge inverter circuit is electrically connected to the output circuit;

[0010] The full-bridge inverter circuit includes a filter inductor, an inverter filter capacitor group, a high-frequency absorption capacitor and an IGBT inverter bridge; wherein the filter inductor is connected in series to the positive end of the DC bus, and the inverter filter capacitor group, the high-frequency absorption capacitor and the IGBT inverter bridge are connected in parallel to the positive and negative ends of the DC bus respectively.

[0011] The following is a technical solution further defined by the utility model, wherein the charging buffer circuit includes an absorption capacitor, a buffer contactor, a buffer resistor, and a resettable fuse; wherein the two ends of the absorption capacitor are respectively connected to the positive end and the negative end of the DC bus, the buffer contactor is connected in series on the positive end of the DC bus, the two ends of the buffer contactor are connected in parallel with a buffer resistor and a resettable fuse, and the buffer resistor and the resettable fuse are connected in series.

[0012] The following is a technical solution further defined by the present utility model, wherein the buffer contactor and the filter inductor are connected in series.

[0013] The following is a technical solution further defined by the present utility model, wherein the output circuit includes a DC-isolating capacitor group, an isolation transformer, and a resonant capacitor group; wherein the DC-isolating capacitor group is connected to the primary winding of the isolation transformer, the two poles of the secondary winding output of the isolation transformer are respectively connected to one end of a resonant capacitor group, and the other ends of the two resonant capacitor groups are respectively connected to the two ends of the inductor.

[0014] Compared with the prior art, the utility model has the following technical effects:

[0015] The utility model designs a backup DC power supply channel, which can automatically disconnect the backup DC power supply, provide a safer power supply method for crystal growth equipment, and effectively avoid equipment output power fluctuations and shutdown failures caused by sudden flash or reduction of the three-phase power supply.

[0016] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of the overall circuit connection relationship of the utility model;

[0019] Figure 2 It is a schematic diagram of the connection relationship between the three-phase input circuit and the DC standby input circuit in the utility model;

[0020] Figure 3 It is a schematic diagram of the connection relationship of the charging buffer circuit in the utility model;

[0021] Figure 4 It is a schematic diagram of the connection relationship of the full-bridge inverter circuit in the utility model;

[0022] Figure 5 It is a schematic diagram of the connection relationship of the output circuit in the utility model. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0024] like Figure 1-5 As shown, a crystal growth induction heating power supply with a DC standby input is provided, comprising a three-phase input circuit, a DC standby input circuit, a charging buffer circuit, a full-bridge inverter circuit and an output circuit.

[0025] The three-phase power supply of 380VAC and 50Hz enters the circuit breaker K1, and then connects to the three-phase rectifier bridge BD1. The rectifier outputs DC+ and DC- are connected to the DC bus; V+ and V- are the DC power input terminals, of which V- is directly connected to the negative end DC- of the DC bus, and V+ is connected to the positive end DC+ of the DC bus through a diode D1. Utilizing the unidirectional conduction characteristics of diode D1, when the three-phase power supply is suddenly cut off or reduced, the output DC voltage of the three-phase rectifier bridge BD1 will also decrease. When the rectified DC voltage is lower than the voltage value of the DC backup power supply V+ and V-, current will flow through diode D1 at the V+ end to supply DC+. When the three-phase power supply returns to normal voltage, the output voltage of the three-phase rectifier bridge BD1 is higher than the voltage of the backup DC power supply V+ and V-, and the diode D1 in the circuit is cut off, realizing the function of automatically disconnecting the backup DC power supply.

[0026] C4 is the absorption capacitor of the three-phase rectifier bridge BD1, and the buffer contactor KP2, buffer resistor RB1 and self-recovery fuse SF1 constitute the charging buffer circuit for the inverter filter capacitor group GCA2. The function of the charging buffer circuit is to eliminate the current impact on the input circuit and the three-phase rectifier bridge when power is turned on, and reduce the impact and interference on the power grid.

[0027] IND1 is the filter inductor, GCA2 is the inverter filter capacitor group, C2 and C3 are the inverter IGBT high-frequency absorption capacitors, and the DC current passes through the IGBT inverter bridge of IGBT1, IGBT2, IGBT3, and IGBT4 to form a full-bridge inverter circuit. During the inverter output, the IGBT turn-on time of each half cycle can be adjusted to achieve adjustable inverter output voltage, which is used to adjust the output current and output voltage.

[0028] The inverter output AC current passes through the DC blocking capacitor group CAP1 to block the DC component to prevent the transformer from magnetic saturation, and then passes through the primary winding of the medium frequency isolation transformer TR1 to transmit the current to the secondary winding of the isolation transformer TR1. The isolation transformer TR1 plays the role of matching the rated impedance of the resonant circuit and output isolation. The two poles of the secondary winding output of the isolation transformer TR1 are respectively connected to one end of the resonant capacitor group CAP2 and CAP3, and the other ends of the resonant capacitor group CAP2 and CAP3 are respectively connected to the two ends of the inductor COIL1 to form an LC series resonant circuit, generating a medium frequency oscillating current in the LC resonant circuit.

[0029] The above is only a preferred embodiment of the utility model, and does not limit the utility model in any form. Any technician familiar with the field can make many possible changes and modifications to the technical solution of the utility model by using the above disclosed methods and technical contents without departing from the scope of the technical solution of the utility model, or modify it into an equivalent embodiment of equivalent changes. Therefore, all equivalent changes made according to the shape, structure and principle of the utility model without departing from the content of the technical solution of the utility model should be included in the protection scope of the utility model.

Claims

1. A crystal growth induction heating power supply with a DC backup input, characterized in that: It includes a three-phase input circuit, a DC standby input circuit, a charging buffer circuit, a full-bridge inverter circuit and an output circuit; The three-phase input circuit comprises a three-phase power supply, a circuit breaker and a three-phase rectifier bridge, wherein the three-phase electricity of the three-phase power supply is electrically connected to the three-phase input terminals of the three-phase rectifier bridge through the circuit breaker, and the rectifier output terminals DC+ and DC- of the three-phase rectifier bridge are electrically connected to the positive terminal and the negative terminal of the DC bus respectively; The DC backup input circuit includes a DC backup power supply and a diode, wherein the V- terminal of the DC backup power supply is electrically connected to the negative terminal of the DC bus, the V+ terminal of the DC backup power supply is electrically connected to the anode of the diode, and the cathode of the diode is electrically connected to the positive terminal of the DC bus; The positive end and the negative end of the DC bus are electrically connected to the charging buffer circuit and the full-bridge inverter circuit, and the output end of the full-bridge inverter circuit is electrically connected to the output circuit; The full-bridge inverter circuit includes a filter inductor, an inverter filter capacitor group, a high-frequency absorption capacitor and an IGBT inverter bridge; wherein the filter inductor is connected in series to the positive end of the DC bus, and the inverter filter capacitor group, the high-frequency absorption capacitor and the IGBT inverter bridge are connected in parallel to the positive and negative ends of the DC bus respectively.

2. A crystal growth induction heating power supply with a DC backup input as claimed in claim 1, characterized in that: The charging buffer circuit includes an absorption capacitor, a buffer contactor, a buffer resistor, and a resettable fuse; wherein the two ends of the absorption capacitor are respectively connected to the positive end and the negative end of the DC bus, the buffer contactor is connected in series on the positive end of the DC bus, the two ends of the buffer contactor are connected in parallel with a buffer resistor and a resettable fuse, and the buffer resistor and the resettable fuse are connected in series.

3. A crystal growth induction heating power supply with a DC backup input as claimed in claim 2, characterized in that: The buffer contactor and the filter inductor are connected in series.

4. A crystal growth induction heating power supply with a DC backup input as claimed in claim 1, characterized in that: The output circuit includes a DC-isolating capacitor group, an isolation transformer, and a resonant capacitor group; wherein the DC-isolating capacitor group is connected to the primary winding of the isolation transformer, the two output poles of the secondary winding of the isolation transformer are respectively connected to one end of a resonant capacitor group, and the other ends of the two resonant capacitor groups are respectively connected to the two ends of the inductor.

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