Several conditions for high frequency heating equipment to match loading
High-frequency induction heating equipment uses the matched transformer for induction heating load matching adjustment in the work, which not only can be simple and convenient in operation, but also makes the adjustment work progress more quickly and efficiently. However, when using this method for load regulation, it is also necessary to briefly introduce the t conditions that need to be referenced in the matching transformer regulation technique.
1. When using a matching transformer for load regulation, the first thing we should pay attention to is that the hollow transformer is easy to realize large capacity and reduce the requirement for capacitance, but this method is limited to primary compensation. As the voltage and power increase, its volume increases accordingly. In addition, the hollow transformer has a large leakage inductance, and the ratio is not equal to the turns ratio. It is difficult to grasp in the design, and it is difficult to achieve when it is relatively large.
2. The selection principle that needs our attention is the characteristic problem of the iron core transformer. In the actual application process, the core transformer has a small leakage inductance, and the ratio is equal to the turns ratio. For a very low load impedance, a larger turns ratio can be made. However, the iron loss of the core transformer is proportional to the square of the frequency, which is likely to cause serious heat generation during high-frequency adjustment, which also increases the requirements for the transformer cooling system, which requires more attention.
3. When using a matching transformer for load regulation of high-frequency heating equipment, we also need to consider the design of the compensation capacitor in many aspects. Under normal circumstances, the compensation capacitor is generally placed on the high side of the matching transformer. When the reactive capacity is provided, the capacitance value can be greatly reduced. Of course, this needs to be considered in consideration of the market price of the selected circuit form, transformer and capacitor.
4. The problem of the number of taps matching the transformer is also a key factor we have to consider. In daily applications, in order to adapt to a variety of loads, the matching transformer should be designed as a multi-tap transformer, but the number of taps is limited by the structure of the transformer, and the adjustment of the load is limited, it is generally difficult to achieve a one-time best match. As the frequency increases, the design of multi-tap transformers is more difficult, which also requires us to adjust the design in time according to the application.
In addition to the above conditions, when using a matching transformer for load regulation of high-frequency heating equipment, such a transformer can function as an electrical isolation in the overall circuit. By analyzing the load characteristics of the series resonant circuit, the equivalent impedance of the series resonant circuit is only related to the equivalent resistance of the tank. Changing the capacitance and inductance values in the equivalent circuit does not affect the equivalent impedance. This characteristic greatly limits the series resonant circuit. Load matching measures. Therefore, the actual device mainly uses a matching transformer to adjust the adjustment load matching state by adjusting the ratio.