PFC circuit control method and device based on load current feedforward

Abstract

The invention discloses a PFC circuit control method and PFC circuit control device based on load current feedforward. The PFC circuit control method comprises steps that based on a PFC circuit, input current, input voltage, load current, and double-busbar voltage are acquired; a difference between the double-busbar voltage and a double-busbar voltage reference value is calculated, and adopts voltage loop input; by adopting the voltage loop input, a voltage loop output quantity is acquired by a controller, and the deviation control of the voltage ring is carried out; a double-busbar voltage difference is calculated, and is a balance loop difference; based on the balance loop difference, the deviation control of the balance ring is carried out to acquire a balance loop output quantity; after the compensation control of the load current is carried out by a current feedforward controller, a feedforward compensation value is output; a difference between the balance loop output quantity and the feedforward compensation value is calculated, and is used as a determined current loop; the determined current loop is compared with the input current, the deviation control of the current loop is carried out to acquire a current loop output quantity; and based on the current loop output quantity, a driving signal used to drive the PFC circuit is acquired.

Description

technical field [0001] The invention relates to the technical field of switching power supplies, in particular to a PFC circuit control method and device based on load current feedforward. Background technique [0002] A power factor correction (Power-Factor Correction, PFC for short) unit can effectively improve power quality and reduce the impact on grid harmonics, and is widely used in power converters. As an AC / DC conversion, the PFC unit realizes an input power factor of 1 on the one hand and a stable output DC on the other hand. For the output topology with dual busbars, it is also necessary to achieve voltage balance between the positive and negative busbars. At present, most of the PFC modeling only considers the balanced load, or only considers the load as the disturbance in the controlled object when the control algorithm is developed. Then, for large disturbances, the voltage between the positive and negative busbars cannot be balanced. Take a three-input single...

AI Technical Summary

Problems solved by technology

Then, for large disturbances, the voltage between the positive and negative busbars cannot be balanced. Taking a three-input single-outlet UPS as an example, when the output is short-circuited, a DC bus high-voltage alarm will occur, which will cause the UPS to work abnormally.

In addition, in the case of high load current, due to the unbalanced busbar, considering the factor of peak voltage, it is necessary to select a semiconductor device with a higher voltage level, resulting in an increase in system cost and a decrease in system efficiency

Images