Junya Sakemi

A new STS model DC-DC converter

This paper presents a new STS (steady-state-error and transient suppression) model based digital control dc-dc converter. In this method, not only the conventional P-I-D control as the feedback one but also the new STS model as the feed-forward one is used. The proposed STS model is consist of two superior functions, one is the steady-state function for expanse of regulation range of output voltage, and another is the exponential function for improvement of transient response. As a result, the proposed method has no steady-state-error against the changes of input voltage Ei and output current Io. In addition, the undershoot of output voltage and the overshoot of reactor current are suppressed to about 8% and 11% as compared with the conventional one in the step change of load resistance from 100Ω to 5Ω. Especially, the convergence time for output voltage is converged instantly. It is confirmed that the new STS model control realizes good characteristics for both the steady and transient state.

A new quick transient response digital control dc-dc converter with smart bias function

The purpose of this paper is to present a new quick transient response digital control dc-dc converter with smart bias function and its design criterion. In the proposed method, not only the conventional P-I-D control as the feedback one but also the smart bias function as the feedforward one is used. The smart bias function consists of two superior functions. One is the steady-state function for the expanse of regulation range of output voltage, and another is exponential function for the improvement of transient response. By using these functions, the proposed method has no steady-state-error against the changes of the input voltage and the output current. In addition, the undershoot of output voltage and the overshoot of reactor current are approximately 92% and 89% smaller than the conventional method in the step change of load resistance from 100Ω to 5Ω. Especially, the convergence time for output voltage is converged instantly. It is confirmed that the smart bias function control technique is useful to realize the high performance digital control method.

Dynamic characteristics of DC-DC converter with novel digital peak current-injected control

This paper presents the dynamic characteristics of the proposed digital control current mode dc-dc converter. In the proposed novel digital control circuit, the peak current-injected control is realized using the combination of the simple dual A-D signal converter and the programmed delay circuit. In 100kHz digitally controlled dc-dc converter, it is seen in simulation that the proposed method has no overshoot of the output voltage and the convergence time that the output voltage is settled to steady-state is only 151µs. The difference between the transient time of the proposed circuit and that of the conventional method is an order of magnitude. Furthermore, the ratio of resolution of the DPWM generator against the output voltage is 0.27% and is satisfied to apply the commercial power supply unit.

A new approach to improve dynamic characteristics of digitally controlled buck-boost dc-dc converter

This paper presents a new digital control buck-boost dc-dc converter with bias model to improve dynamic characteristics. The buck- boost converter needs to respond appropriately to changing input voltage and load change with wide input voltage. This approach makes adjustment to the bias value by input voltage and output current. As a result, it is revealed that not only the dynamic characteristics but also static characteristics can be improved and it is effective for wide range input voltage.

A new auto-bias method for digital control dc-dc converter

Main content of this paper is a new auto-bias method for digital control dc-dc converter. In the proposed method, not only the P-I-D control as the feedback one but also the new auto-bias method as the feedforward one is used. The new auto-bias method consists of two superior functions. One is the steady-state function for the expanse of regulation range of output voltage, and another is exponential function for the improvement of transient response. By using these functions, the proposed method has no steady-state-error against the changes of the input voltage and the output current. In addition, the undershoot of output voltage and the overshoot of reactor current are approximately 92% and 89% smaller than the conventional method in the step change of load resistance from 100Ω to 5Ω. Especially, the convergence time for output voltage is converged instantly. It is confirmed that the new auto-bias model control technique is useful to realize the high performance digital control method.

A New Prediction Based Digital Control DC-DC Converter

This paper presents a novel prediction based digital control dc-dc converter. In this method, addition to the P-I-D control as the feedback control, the prediction based control is used as the feedfoward control. In the feedfoward control, the neural network based method is adopted. This works to improve the transient response very effectively when the load is changed quickly. As a result, the undershoot of the output voltage and the overshoot of the reactor current are suppressed effectively as compared with the conventional one in the step change of load resistance. It is confirmed that the prediction based control technique is useful to realize the high performance digital control method for the dc-dc converter.

An auto-tuning digital control for buck-boost dc-dc converter

This paper presents two auto-tuning digital control methods for buck-boost dc-dc converter. The buck-boost dc-dc converter is used with wide input voltage changing. The suitable proportional gain and bias value are changing against the input voltage of the converter. So, we took two methods that changing proportional gain and changing bias value against the input voltage of the converter. As a result, the superior output characteristics can be realized.

A novel smart digital control dc-dc converter

This paper presents a novel smart digital control method using P-I-D control and a model control. This control circuit is able to detect not only the average output voltage but also the input voltage and the output current to improve the dynamic characteristics. As a result, the undershoot of the output voltage, the overshoot of the reactor current and convergence time of the output voltage are improved to 67.7%, 39.6% and 72.5% as compared with the conventional one when the step change of the load resistance R from 100 Ω to 5Ω. Moreover, there are little voltage changes when the step change of the input voltage Ei. It is confirmed that the proposed model control technique is useful to realize the high performance digital control method of dc-dc converter.