Haruhi Eto

Output characteristics of DC-DC converter with DSP control

This paper presents the output characteristics and design criterion of the 100 kHz high-speed DC-DC power converter with the DSP control. The circuit configuration and operation principle of this circuit is described. Also, the regulation characteristics in the PID control are examined theoretically and experimentally. As a result, the relationship between the regulation characteristics of the DC-DC converter and the quantization width of the A-D signal converter is clarified, and then the design criterion of the 100 kHz high-speed DC-DC converter with the DSP control is defined.

Novel Digital Controller with Static Model Reference for Switching DC-DC Power Converters

It is often observed that the operation of the digitally controlled dc-dc power converter becomes unstable when the relatively large integral coefficient is used to extend the regulation range of the output voltage to handle variations in the input voltage and load. This paper presents a novel digital controller with static model reference for switching dc-dc power converters to improve the performance characteristics and discusses its design-oriented analysis in the steady-state characteristics. It is clarified theoretically and experimentally that using the static model reference, the wide regulation range of the output voltage to handle variations in the input voltage and load current can be achieved with the appropriate small integral coefficient in the digital P-I-D controller. Therefore, since the integral coefficient is selected to cover the maximum instantaneous variation value of the static reference model, the integral coefficient is small and the operation is always stable.

A new quick response digital control dc-dc converter with dynamic unstable gain

In this paper, we present a new quick response digital control dc-dc converter based on a dynamic unstable gain to improve transient response. In the proposed method, the proportional gain is set to the small value in the steady state and the large value over the stability limit for only a short time in the transient state. Compared with the conventional PID, the undershoot, the overshoot and convergence time are improved by 48%, 71% and 84%, respectively. Generally, when the control gain is set to very large value, the capacitance of output smoothing capacitor must be set to large value simultaneously to maintain the stability of system. That can be reduced and the miniaturization of main circuit can be expected because the very large gain is set for only a short time to improve the transient response in the proposed method.

An FPGA Based Heterogeneous Redundant Control System Using Controller Virtualization

This paper describes heterogeneous redundancy of FPGA based control system using cloud. Since conventional cloud servers have problems in responsiveness, we propose the concept and architecture of controller virtualization using FPGAs. However, we should consider the negative effect on the controllability by the communication delay when control is performed using the cloud. We evaluated the stability of control using cloud by means of a simulation for a representative process control model.

Miniaturization of buck-boost DC-DC converter with fast P control

This paper presents a consideration about miniaturization of buck-boost dc-dc converter with the fast P control. From frequency characteristics, it is identified that fast P control method is useful to suppression of output capacitance and circuit miniaturization.

A Study of FPGA Instance Based PLC Architecture Design and Automatic Generation Algorithm of Logic Code

In this paper, an architecture of FPGA instance based PLC and a method of converting IL (instruction list) of PLC to instances are proposed assuming that the PLC is installed on the cloud. It is attempted to improve responsiveness by dedicated circuitry using instances (libraries) and concurrent processing that are specific features of FPGA hardware. The proposed architecture in the FPGA consists of the instance part (calculation circuit that is correspond to the instruction of the PLC) the input/output circuit/output memory, and the state machine. In this paper, a benchmark test of PLC is converted into instances by automatic conversion algorithm to be implemented with the proposed architecture, and it is confirmed by logic simulation that the FPGA instance based PLC operates at high speed as expected.

Transient response of digital peak current mode boost converter for DC bus voltage compensation

The boost type dc-dc converter is used for compensation of dc bus voltage in the dc power feeding system such as the renewable energy system. It should be operated stably to improve reliability of the system. The peak current mode control is applied to operate stably because the boost type dc-dc converter tends to be unstable. However, a peak value of reactor current cannot be captured in the digital controller. In this paper, a digital peak current mode control boost converter with conversion from current to frequency and using a frequency detector for a peak current detection in real time is presented. The effectiveness of the proposed method is verified by the comparison of the transient response under changing an input voltage between the conventional PID control and the proposed method.

A consideration of signal frequency detector in digital peak current mode dc-dc converter

The purpose of this paper is to reveal the designing of the static characteristic of the digital peak current mode dc-dc converter using a voltage controlled oscillator (VCO). In the proposed method, it is able to sample the reactor current by using the VCO and the delay circuit. The improvement of the dynamic characteristic and the analysis of the proposed method have already been revealed. However the design method in the static characteristic of the proposed method has not been clear. In this paper, the analysis about the resolution of the output voltage is revealed for the designing of the proposed method in static characteristic. The change of the output voltage against the change of the delay time in the signal frequency detector is confirmed by comparing the analysis result and simulation results. Furthermore, the effect, which the signal frequency detector gives to the output voltage in the transient state, is discussed.

Improvement in transient response of fast P control DC-DC converter with static model

The purpose of this paper is to propose the digital control method that is comprised of the fast P control and model control for an improvement of the transient response of the dc-dc converter. The electronic devices are required the operation in the standby mode and the quick return to the active mode. The fast transient response of the dc-dc converter in such condition is important. In this paper, the fast P control is combined with the model control. Therefore, the transient response in such situation is improved because the operating point is optimized according to the load current. From the results, in the case of the load step from DCM to CCM, the undershoot and the convergence time are improved by about 80%.