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In this paper, the effect of phase shift modulation on the LLC resonant converter for an interleaved LLC resonant converter with phase shift modulation is investigated. The LLC resonant converters can achieve zero voltage switching (ZVS) of the primary switches and the zero current switching of secondary switches. Due to the sinusoidal shapes and discontinuous conduction of secondary current, the...
The data center of the cloud which supports the recent communications infrastructure requires the high reliable control systems in order to control its enormous electric power and exhaust heat. It is important to reduce the energy wasted by the control systems. The FPGA is watched because of the low energy, the long sustainability, and the simple architecture. It is clarified that the FPGA realizes...
This paper presents a current sensor-less boundary current mode PFC converter. In particular, the ac-dc converter with a boundary current mode control has the following several advantages. One is that it has the capability to achieve the low input current distortion and the unity power factor can be obtained in theory. Another is that it is possible to reduce the switching loss because the inductor...
This paper proposes a novel modulation method of the full bridge three-level LLC resonant converter. The voltage gain of the converter is analyzed by First Harmonic Approximation technique using this modulation method. Therefore designers can easily calculate the converter parameters. A 385V input, 225 to 378V/6.6kW output prototype converter shows 98.14% peak efficiency.
The purpose of this paper is to discuss performance characteristic of digital peak current mode control switching power supply. The proposed method can capture the peak current value in real time by using the voltage controlled oscillator (VCO), the programmable delay circuit and the signal frequency detector. Its transfer function is derived analytically. Also, the frequency characteristics are revealed...
The purpose of this paper is to reveal the effect of control gain in the proposed fast PD control method. A bode diagram is described using a loop transfer function. The variation tendency of frequency characteristics for different values of fast proportional gain and fast differential gain is discussed. Moreover, the frequency characteristics of proposed method are compared with the conventional...
The analytical approach for the proposed method is carried out in this paper. The dynamic characteristics are discussed by using Nyquist diagram. Compared with the conventional PID control, the stability region of proposed method expands. It is confirmed in the simulation. Moreover, the transient responses of conventional PID control and proposed method are discussed in the stability region. In the...
The purpose of this paper is to present a digital fast P and slow ID control dc-dc converter using A–D converters in different resolutions. In the proposed method, the operation parts are divided into the P control and the ID control. Moreover, the high-speed and low resolution A–D converter is set for the P control, and the very low-speed and high resolution one is set for the ID control. In the...
This paper presents a neural network based PID parameter selection control to improve the transient response of dc-dc converters. In the conventional PID control, parameters of it such as proportional, integral, and differential coefficients are selected as fixed parameters to regulate both transient and steady-state characteristics simultaneously as much as possible. The parameter setting of PID...
The purpose of this paper is to present control characteristics of digital peak current mode dc-dc converter. It is difficult to implement the digital current control. An expensive A-D converter is required in order to sample a current. Furthermore, even if an A-D converter can sample the current, it is also needed the high-performance processor to process the sampling data. The peak current can be...
The purpose of this paper is to present a digital control method which suppresses the delay-time for the switching power supplies. The operation part of power supply has two controllers as the fast PD and the conventional PID, which are processed in parallel. Therefore, the fast PD control can improve the transient response of switching pulses. Obtained simulation results show that the proposed method...
Recent years have seen the popularization of model based development (MBD) using models based on block diagrams. In many mechatronics systems, including automobile engine control and the brake control, a closed loop control is used to manage controls based on feedback data from control target objects. In order to develop a closed loop control using model base, a plant model that simulates the behavior...
Since the Great East Japan Earthquake, everyone has come to relook how to use electric energy. In addition, people who say that it should aggressively install safe and clean energy system have increased. To create city which is learned from nature, supported by science and technology, we started activity of community in Fukuoka and Yokohama. This paper introduces overview of smart energy system and...
This paper presents a novel sensorless model control dc-dc converter. In the proposed method, the output current is predicted from the duty ratio and the output voltage in order to exclude the sensing resistor. Only the output voltage and the input voltage are detected. The transient characteristics in the proposed method without the current detection are compared to the existing proposed method and...
The purpose of this paper is to present a influences of parameter deviations on operation of a novel current sensorless AC-DC converter are discussed. The off time is calculated based on the equations of each operating state for boundary current control mode. The relationship among the THD, power factor and efficiency, and circuit parameter errors are discussed. When the circuit parameter varies from...
This paper presents a novel interleaved LLC resonant converter using phase shift modulation (PSM). The LLC resonant converters can achieve zero voltage switching (ZVS) of primary switches and zero current switching (ZCS) of secondary switches. However, the peak of secondary current is large due to the discontinuous current in secondary side. The PFM controlled interleaved LLC resonant converter has...
This paper presents a new high performance dc-dc converter with sensorless model reference modification. In the proposed method, output current is predicted from the duty ratio and the output voltage in order to eliminate the sensing resistor for output current detection. Only the output voltage and input voltage are detected for feedback and feed-forward. The bias value of the P-I-D control is changed...
The purpose of this paper is to present a new integral coefficient change method that is not required the load current detection. The integral coefficient is changed based on the on-time of main switch. It uses two kinds of hysteresis function for stable operation around the boundary point of continuous conduction mode and discontinuous conduction mode. One uses the shape of rectangular And another...
The purpose of this paper is to presents a new integral gain switchover method that has the unique hysteresis function in which the current sensor circuit is not required. In this paper, two kind of integral gain switchover method is indicated. One is te two-step switchover method having the rectangle hysteresis function. The other is slope switchover method having rectangular triangle hysteresis...
The purpose of this paper is to present a digital control method which suppresses the delay-time for the switching power supply. Generally, there is the delay-time caused by the A/D conversion time and the calculation time in the digital control. It causes the worsening of the transient response and brings the instability of the system. The proposed method can suppress the delay-time and improve the...
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