| 摘要 |
PURPOSE: An input current restriction control system for a booster chopper is provided to prevent the circuit element from damage by limiting the input current applied to the booster chopper when the input current increases by overload. CONSTITUTION: The input current restriction control system comprises two current reversing protective diodes(D1,D2) for generating the rectified input DC current(Vin), a capacitor(C1), two switching elements(Q1,Q2) for controlling the input current applied to the diodes(D1,D2) respectively, a voltage control unit(10) for generating the reference input current(Iref), and a current control unit(20) for controlling the switching ON operation by using the difference between the reference input current and the input current. The voltage control unit has the first subtractor(11) for producing the difference voltage between applied input voltage(V_dc) and the reference voltage, the first proportional integral controller(12) for generating the integrated difference voltage, and the first limiter for limiting the amplitude of the integrated difference voltage within a fixed level. The current control unit has the second subtractor(21) for producing the difference current between applied input current(V_in) and the reference current, the second proportional integral controller(22) for generating the integrated difference current, and the second limiter for limiting the amplitude of the integrated difference current within a fixed level. In the overcurrent state, the second limiter generates a signal to turn on the switching elements, which restricts the input current and decreases the input DC voltage.
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