Kazushi Watanabe

A NEW DESIGN OF ROBUST DIGITAL CONTROLLER FOR DC-DC CONVERTERS

Abstract Robust DC-DC converters which can cover extensive load changes and also input voltage changes are needed. In this paper, we propose a new method for designing good approximate 2-degree-of freedom (2DOF) digital controller which makes the control bandwidth wider, and at the same time makes a variation of the output voltage very small at sudden changes of resistive load. The proposed approximate 2DOF digital controller is actually implemented on a DSP and is connected to a DC-DC converter. Experimental studies demonstrate that this type of digital controller can satisfy given specifications.

High Resolution DPWM Generator for DC-DC Converter using Pulse Composite Technique

In recent years, digitization of all control parts in switching power supplies including PWM generators is progressing for demands such as intelligent performances and common use of hardware, etc. Then, a problem is in the resolution of digital PWM generators for improving control performances. Since the digital PWM generator is constituted using a counter, a carrier wave turns into a stairs wave, and step amplitudes is decided with a clock cycle. When the clock cycle is fixed, the resolution becomes low as the switching frequency becomes high. Consequently, the accuracy of output voltage becomes bad. In this paper, a method for remarkably improving the resolution of the digital PWM generator using the pulse composite technique is proposed. The method is realizable by some parts and easy computation, and is applied to the digital PWM generator built-in DSP. The usefulness and practicality are verified by experiments

Digital Robust Control for DC-DC Converter with Second-Order Differential Characteristics

Robust DC-DC converter which can cover extensive load changes and also input voltage changes with one controller is needed. Then the demand to suppressing output voltage change becomes still severer. We proposed an aproximate 2DOF digital controller which realizes the startup response and dynamic load response independently. The controller makes the control bandwidth wider, and at the same time makes a variation of the output voltage small at sudden changes of loads and the input voltages. In this paper, a new approximate 2DOF digital control system with additional zeros is proposed. Using additional zeros a second- order differential transfer characteristics between equivalent disturbances and an output voltage is realized. So the new controller makes a variation of the output voltage more small at sudden changes of loads and the input voltages. This controller is actually implemented on a DSP and is connected to a DC-DC converter. Experimental studies demonstrate that this type of digital controller can satisfy given severe specifications.

New Approximate 2DOF Digital Controller for DC-DC Converter with Second-Order Differential Characteristics

Robust DC-DC converter which can cover extensive load changes and also input voltage changes with one controller is needed. Then the demand to suppressing output voltage change becomes still severer. We proposed an approximate 2DOF digital controller which which realizes the start-up response and dynamic load response independently. The controller makes the control bandwidth wider, and at the same time makes a variation of the output voltage small at sudden changes of loads and the input voltages. In this paper, a new approximate 2DOF digital controller using additional zeros is proposed. The new controller makes a variation of the output voltage more small at sudden changes of loads and the input voltages. This controller is actually implemented on a DSP and is connected to a DC-DC converter. Experimental studies demonstrate that this type of digital controller can satisfy given severe specifications.

A Resolution Improving Method of Digital PWM using Pulse Composite Technique

In recent years, digitization of all control parts in switching power supplies including PWM generators is progressing for demands such as intelligent performances and common use of hardware, etc. Then, a problem is in the resolution of digital PWM generators for improving control performances. Since the digital PWM generator is constituted using a counter, a carrier wave turns into a stairs wave, and step amplitudes is decided with a clock cycle. When the clock cycle is fixed, the resolution becomes low as the switching frequency becomes high. Consequently, the accuracy of output voltage becomes bad. In this paper, a method for remarkably improving the resolution of the digital PWM generator using the pulse composite technique is proposed. The method is realizable by some parts and easy computation, and is applied to the digital PWM generator built-in DSP. The usefulness and practicality are verified by experiments

New Approximate 2DOF Digital Controller for DC-DC Converter with Additional Zeros

Robust DC-DC converter which can cover extensive load changes and also input voltage changes with one controller is needed. Then the demand to suppressing output voltage change becomes still severer. We proposed an aproximate 2DOF digital controller which realizes the start-up response and dynamic load response independently. The controller makes the control bandwidth wider, and at the same time makes a variation of the output voltage small at sudden changes of loads and the input voltages. In this paper, a new approximate 2DOF digital controller using additional zeros is proposed. The new controller makes a variation of the output voltage more small at sudden changes of loads and the input voltages. This controller is actually implemented on a DSP and is connected to a DC-DC converter. Experimental studies demonstrate that this type of digital controller can satisfy given severe specifications.

A method to improve a resolution of digital PWM generator for DC-DC converter control

In recent years, digitization of all control parts in switching power supplies including PWM generators is progressing for demands such as intelligent performances and common use of hardware, etc. Then, a problem is in the resolution of digital PWM generators for improving control performances. Since the digital PWM generator is constituted using a counter, a carrier wave turns into a stairs wave, and step amplitudes is decided with a clock cycle. When the clock cycle is fixed, the resolution becomes low as the switching frequency becomes high. Consequently, the accuracy of output voltage becomes bad. In this paper, a method for remarkably improving the resolution of the digital PWM generator using the pulse composite technique is proposed. The method is realizable by some parts and easy computation, and is applied to the digital PWM generator built-in DSP. The usefulness and practicality are verified by experiments

Design of good approximate 2-degree-of-freedom digital controller for robust DC-DC converter

Robust DC-DC converter which can cover extensive load changes and also input voltage changes is needed. In this paper, we propose a method of designing good approximate 2-degree-of freedom (2DOF) digital controller which makes the control bandwidth wider and at the same time makes a variation of the output voltage very small at a sudden change of resistive load. The proposed approximate 2DOF digital controller is actually implemented on a DSP and is connected to a DC-DC converter. Experimental studies demonstrate that this type digital controller can satisfy given specifications.