Active power factor correction (PFC) control circuit based on complex programmable logic device (CPLD)

Abstract

The invention discloses an active power factor correction (PFC) control circuit based on a complex programmable logic device (CPLD). The active PFC control circuit based on the CPLD comprises a CPLD, a single chip circuit, an analog digital (AD) conversion circuit, a clock source, a current sampling circuit which is used to sample current for inductance in BOOST type PFC circuit topological structure, the CPLD is composed of a first buffer register, a second buffer register, a period register, a first numeric comparator, a second numeric comparator, a current reference register, a pulse width modulation (PWM) module, and an AD conversion logic controller, the clock source is connected into a clock signal input terminal of the CPLD, the AD conversion circuit is communicated with the AD conversion logic controller, and the current sampling circuit is connected with the AD conversion circuit. The first numeric comparator and the second numeric comparator are combined to control the PWM pulse width and the PWM pulse is output by the PWM module, and then the PWM pulse is used to control switching of an insulated gate bipolar translator (IGBT) of the BOOST type PFC circuit topological structure so that actual inductive current of the BOOST type PFC circuit topological structure changes with a reference value of inductive current. The active PFC control circuit based on the CPLD is high in the requirement for an external central processing unit (CPU), degree of harmonic distortion of an input current is extremely small, and controlled robustness is good.

Description

technical field [0001] The invention relates to a power factor correction circuit, in particular to a CPLD-based active PFC control circuit. Background technique [0002] The rapid development of electronic technology and power electronic technology, and the use of a large number of power electronic equipment have brought increasingly serious harmonic and reactive power hazards to the power grid. Power factor correction (PFC) technology is generally used in uninterruptible power supply (UPS) to solve the problem of harmonic pollution, such as figure 1 The shown BOOST type PFC circuit topology is mainly composed of inductor L1, IGBT tube, diode D1, capacitor C1, resistor Z1 and rectifier bridge. [0003] Traditional active PFC circuits are implemented by integrated analog control chips, such as UC3854, L4981A / B, etc., but the analog control chips themselves have some defects, such as components are prone to aging and thermal drift; the control method is not flexible, and the...

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Problems solved by technology

[0006] However, there are also some disadvantages in pure DSP software control, such as the contradiction between sampling frequency and switching frequency, control delay that always lags behind a switching beat, complex mathematical modeling and algorithm design, and high operating speed of DSP. Requirements, difficulty in setting PI parameters, sensitivity to circuit parameters, etc.

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