CN201699603U - High frequency power supply for monocrystalline silicon furnace - Google Patents

Abstract

The utility model discloses a high frequency power supply for a monocrystalline silicon furnace, which comprises a main control circuit, an input reactor, a three-phase rectifier bridge, a power module and a filter loop, wherein the power module comprises an RC filter circuit, a phase shift full-bridge ZVS-PWM converter, a high-frequency step-down transformer and a fast diode rectifier unit which are sequentially connected. The utility model has small volume, light weight, low energy consumption and high reliability, is used for producing monocrystalline silicon, and can greatly reduce cost.

Description

High frequency power supply for monocrystalline silicon furnace

technical field

The utility model belongs to a power module, in particular to a power module used in a single crystal silicon furnace.

Background technique

With the rapid development of the photovoltaic industry, the demand for monocrystalline silicon has also increased. Coupled with the impact of the world's economic environment, how to reduce the production cost of monocrystalline silicon has become an urgent problem to be solved. However, in the production process of monocrystalline silicon Among them, the main energy-consuming equipment is the power supply of the monocrystalline silicon furnace, so how to reduce the energy consumption of the power supply has become the key to energy saving.

At present, there are mainly two types of power supplies used in monocrystalline silicon furnaces: 6-pulse rectifier power supply and 12-pulse double-bridge rectifier power supply. Figure 4 shows the circuit diagram of a 6-pulse rectifier power supply, which mainly uses a three-phase five-column dry-type rectifier transformer for rectification. The primary side uses a thyristor for voltage regulation, and the secondary side uses a diode for rectification. The loss is large, and the ripple coefficient of the output waveform is large, as shown in Figure 5; because the time and power consumed by the monocrystalline silicon furnace in the chemical state and the equal-diameter state are quite different, the rectifier transformer only uses a percentage for most of the time. 70% capacity operation, high power consumption, low utilization. Figure 6 shows the circuit diagram of the 12-pulse double-bridge rectifier power supply. The rectifier transformer is mainly used for rectification, and the rectifier transformer uses double-winding output. The balanced reactor adjusts the output current of the dual windings, and the adjusted output waveform is shown in Figure 7; although the output waveform of the 12-pulse double-bridge rectifier power supply has improved harmonic content compared with the output waveform of the 6-pulse rectifier power supply, but Compensation devices need to be added. Moreover, these two traditional power supplies both use rectifier transformers, which are large in size and heavy in weight, about 1300-2000Kg. Processing such rectifier transformers requires a large amount of copper and steel materials; moreover, rectifier transformers are mostly water-cooled. Type and air-cooled type also need to consume external energy, not only consumes a lot, but also is inconvenient to install, which is not conducive to mass production.

Theoretical analysis and practical experience show that the volume and weight of electrical products are inversely proportional to the square root of their power supply frequency. When the power is increased from power frequency 50Hz to 20kHz, the volume and weight of electrical equipment will be reduced to one percent of the power frequency design Five to ten percent. Therefore, how to find a high-frequency power supply for the production of monocrystalline silicon has become the direction of people's research.

Utility model content

The technical problem solved by the utility model is to provide a high-frequency power supply with small volume, light weight, low energy consumption and high reliability.

In order to solve the problems of the technologies described above, the technical solution adopted by the utility model is:

A high-frequency power supply for monocrystalline silicon furnaces, including a main control circuit, an input reactor, a three-phase rectifier bridge, a power module and a filter circuit, wherein the main control circuit is used to control the working status of each module in real time; the input reactance connected to the three-phase input AC power supply, used to reduce system harmonics; the input terminal of the three-phase rectifier bridge is connected to the output terminal of the AC incoming line input reactor, used to rectify the input AC power supply to DC power supply, and Output the rectified DC signal to the power module; the power module converts the DC signal into a high-frequency AC signal through the high-frequency inverter, and then outputs it to the filter circuit after step-down and rectification; the filter circuit is used to convert the The DC signal output by the power module is filtered and then output.

The improvement of the utility model is that: the power module includes an RC filter circuit, a phase-shifting full-bridge ZVS-PWM converter, a high-frequency step-down transformer, and a rectification unit connected in sequence. The rectification unit is a fast diode rectification unit. Among them, the phase-shifted full-bridge ZVS-PWM converter inverts the input DC signal into a high-frequency AC signal, and the high-frequency step-down transformer is used to step down the high-frequency and high-voltage AC signal to the withstand voltage range of the fast diode rectifier unit. Diodes are used to rectify high-frequency low-voltage AC signals into DC signals.

The improvement of the power module is that: the power module is at least two.

Owing to adopting above technical scheme, the technological progress that the utility model obtains is:

The smoothing reactor adopted at the input end of the utility model effectively reduces the harmonic content of the system, which is beneficial to the safety and stability of the power supply operation. The phase-shifted full-bridge ZVS-PWM converter adopted is a soft switching control technology, which can be turned on or off under zero voltage conditions, and turned off or turned on under zero current conditions. Compared with hard switching, its loss is smaller. The power loss of the switching tube is greatly reduced, and the noise pollution and electromagnetic interference of the power supply are reduced; the voltage change rate and current change rate are greatly reduced by using this soft switching technology, which can eliminate the corresponding electromagnetic interference and radio frequency interference, and improve the efficiency of the converter. While improving the reliability and conversion efficiency, the volume and weight of the converter are reduced, thus ensuring that the high-frequency power supply composed of multiple sets of power modules will neither affect each other nor interfere with other control equipment. The operating frequency of the IGBT inverter set in the phase-shifted full-bridge ZVS-PWM converter is about 20kHz. The input end of the IGBT inverter adopts the busbar stacking technology, which not only effectively uses the space, but also ensures that the IGBT input line has a high The input impedance and low conduction voltage drop reduce the damage to IGBT caused by voltage spikes, prolong the service life of IGBT, reduce system noise and electromagnetic interference, facilitate installation and on-site maintenance, and increase system reliability. The high-frequency step-down transformer in the power module is small in size and light in weight, only about 15kg, and the transformer adopts iron-based nanocrystalline iron core, which has high saturation magnetic induction, high magnetic permeability, low coercive force and low loss And good temperature stability and other advantages, so the high frequency transformer has the characteristics of small size, high efficiency, low excitation power and so on. When the AC signal stepped down by the high-frequency step-down transformer in the power module is output through the rectifier unit, the fast diode used has the characteristics of fast recovery speed, tube voltage drop and low loss. There are more than two sets of power modules, and each independent power module is in parallel working state. Using current sharing technology, all modules share the load current. Even if one of the modules fails, other modules will distribute the load current evenly. The capacity of the equipment and the requirements of high current output are satisfied, and only by adding redundant power modules with small power compared to the whole system, the stability of the system is greatly improved, and the continuous operation of the equipment is fully guaranteed.

In summary, the utility model constituted by the above-mentioned technical features has the following advantages:

1) Small size and light weight;

2) High reliability: The power module of the high-frequency power supply adopts the N+1 redundant design concept, one for N standby, to ensure the continuous operation of the equipment;

3) High power factor: the power factor is not less than 0.98, which reduces line loss and improves the utilization rate of power supply and distribution transformers;

4) Low loss and high efficiency: the conversion efficiency can reach 92%, which meets the requirements of the current low-carbon society;

5) Large output power: the maximum DC output voltage is 60V, the current is 3000A, and the power can reach 180kW;

6) Low ripple factor: ripple factor ≤ 0.2%;

7) The control precision is high, which can prolong the service life of the load; and the output waveform is a smooth DC wave, which ensures the stability of the power supply.

Description of drawings

Fig. 1 is a block diagram of the utility model;

Fig. 2 is a structural block diagram of the utility model power module;

Fig. 3 is the output waveform of the present utility model;

Figure 4 is a schematic diagram of a 6-pulse rectifier power supply;

Figure 5 is the output waveform of the 6-pulse rectifier power supply;

Figure 6 is a schematic diagram of a 12-pulse double-bridge rectifier power supply;

Figure 7 is the output waveform of the 12-pulse double-bridge rectifier power supply.

Among them: AC. AC power supply, DC. DC signal, SCR. Thyristor voltage regulating unit, D. Diode rectifier unit, T. Transformer.

Detailed ways

The utility model will be further described in detail below in conjunction with specific embodiments.

Figure 1 is a high-frequency power supply for monocrystalline silicon furnaces, including a main control circuit, an input reactor, a three-phase rectifier bridge, a power module, and a filter circuit, where the power module includes RC filters connected in sequence as shown in Figure 2 circuit, a phase-shifted full-bridge ZVS-PWM converter, a high-frequency step-down transformer, and a fast diode rectifier unit. In this embodiment, there are three sets of power modules.

The electrical connection relationship of the utility model is: the input reactor, the three-phase rectifier bridge, the power module and the filter circuit are electrically connected sequentially; the main control circuit is electrically connected with the input reactor, the three-phase rectifier bridge and the power module respectively, and each module is controlled in real time The working state; the current signal of the filter circuit is fed back to the main control circuit, so that the main control circuit can make work instructions according to the detected current signal.

The working principle of the utility model is: the AC power supply AC is input to the input reactor, and then through the three-phase rectifier bridge, the rectified DC signal is input to the power module. At this time, the signal is filtered by the RC filter circuit in the power module. The phase-shifted full-bridge ZVS-PWM converter is inverted into a high-frequency AC signal, and the high-frequency AC signal is stepped down by a high-frequency step-down transformer into a high-frequency and low-voltage AC signal within the withstand voltage range of a fast diode. After being rectified by a fast diode rectifier unit, a DC signal is output; the DC signal at this time is then filtered by a filter circuit to output a smooth DC wave, as shown in Figure 3.

Claims (4)

1. A high-frequency power supply for monocrystalline silicon furnaces, comprising a main control circuit, a three-phase rectifier bridge and a filter circuit, characterized in that: it also includes an input reactor and a power module, wherein The main control circuit is used to control the working status of each module in real time; Input reactor, connected with three-phase input power, used to reduce system harmonics; A three-phase rectifier bridge, the input end of which is connected to the output end of the input reactor, used to rectify the input AC power into DC power, and output the rectified DC signal to the power module; The power module converts the DC signal into a high-frequency AC signal through the high-frequency inverter, and then outputs it to the filter circuit after step-down and rectification; The filter circuit is used to filter the DC signal output by the power module and then output it. 2. The high-frequency power supply for monocrystalline silicon furnace according to claim 1, characterized in that: the power module includes an RC filter circuit connected in sequence, a phase-shifted full-bridge ZVS-PWM converter, a high-frequency step-down Transformer, and rectifier unit. 3. The high frequency power supply for monocrystalline silicon furnace according to claim 2, characterized in that: the rectification unit is a fast diode rectification unit. 4. The high-frequency power supply for monocrystalline silicon furnace according to any one of claims 1 to 3, characterized in that there are at least two power modules.

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