KKST patch plug-in active passive crystal oscillator hot sale 24.576000MHZ

description:

The intermediate frequency power supply is widely used in the fields of melting, diathermy, quenching, welding, etc. Different application fields have different requirements for the intermediate frequency power supply. Therefore, the control circuit and the main circuit of the intermediate frequency power supply have different structural forms. Proficiency in the basic working principle of these circuits and the basic characteristics of power devices is a prerequisite for good work. Only on this basis can we accurately and quickly analyze the cause of the fault and take effective measures to eliminate the fault.

Fault phenomenon

The medium frequency induction heating device of our company was introduced by Xi'an Haidexin Electric Co., Ltd. in 2005. When the equipment was put into use for 2 years, when the molten ferrophosphorus was heated, the power could not be raised to the set value, and the system overcurrent tripped. Repeatedly invert the side product I聃 tube. Seriously affect the normal operation of production.

system introduction

The main circuit includes a parallel load resonant circuit composed of a rectifier transformer, a rectifier, a DC reactor, an inverter, a capacitor and an induction heating coil, as shown in Fig. 2. Rectifier transformer 750kVA, 10kV, 575V; using thyristor i-phase full-controlled rectification · 9 reactor has smoothing effect, filtering out high-order harmonics; inverter consists of single-phase full-control bridge, output power 1000kw, input l}{{ Voltage 780V, current 1200A maximum frequency 1000Hz.

In addition to the inverter final stage trigger circuit board, the control system is made into a printed circuit board structure, which is functionally divided into a rectification trigger part, a regulator part, an inverter part, and a startup verification part. The control system detects the intermediate frequency voltage and the capacitor branch current, and controls the trigger of the inverter thyristor by starting the calculation and comparison of the verification part to ensure that the back pressure time tB is greater than the thyristor off time tq.

The above is part of the information, see the PDF document for details!