Topic
Voltage converter
About: Voltage converter is a research topic. Over the lifetime, 5667 publications have been published within this topic receiving 47219 citations.
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TL;DR: In this article, a method based on partitioning the system's admittance matrix and deriving an efficient time-varying Thevenin's equivalent for the converter part is presented.
Abstract: The number of semiconductor switches in a modular multilevel converter (MMC) for HVDC transmission is typically two orders of magnitudes larger than that in a two or three level voltage-sourced converter (VSC). The large number of devices creates a computational challenge for electromagnetic transient simulation programs, as it can significantly increase the simulation time. The paper presents a method based on partitioning the system's admittance matrix and deriving an efficient time-varying Thevenin's equivalent for the converter part. The proposed method does not make use of approximate interfaced models, and mathematically, is exactly equivalent to modelling the entire network (converter and external system) as one large network. It is shown to drastically reduce the computational time without sacrificing any accuracy. The paper also presents control algorithms and other modelling aspects. The efficacy of the proposed method is demonstrated by simulating a point-to-point VSC-MMC-based HVDC transmission system.
720 citations
Patent•
09 Dec 1981
TL;DR: In this paper, a DC-to-DC voltage converter is described for converting the voltage from a battery to provide a power supply voltage whose value can be equal to the battery voltage multiplied by or divided by a non-integral factor, e.g. 2/3.
Abstract: A DC-to-DC voltage converter is disclosed for converting the voltage from a battery to provide a power supply voltage whose value can be equal to the battery voltage multiplied by or divided by a non-integral factor, e.g. 2/3. The converter operates on the principle of capacitor charge switching, and high conversion efficiency is achieved in operation at very low levels of supply current, such as are utilized in an electronic timepiece.
650 citations
Patent•
14 Jan 2003
TL;DR: In this article, a duty ratio D (Vb/Vc*) as a drive instruction of the DC/DC converter is calculated, where the voltage Vb, the electromotive force Vbo of the battery, and the charge/discharge current Ib is calculated.
Abstract: By using a target voltage Vc* of a capacitor connected to the output side of a DC/DC converter and a voltage Vb of a battery connected to the input side of the DC/DC converter, a duty ratio D (Vb/Vc*) as a drive instruction of the DC/DC converter is calculated (S100, S102). By using the voltage Vb, the electromotive force Vbo of the battery, and the charge/discharge current Ib of the battery, an internal resistance Rb ((Vbo - Vb)/Ib) is calculated (S104). According to the internal resistance Rb and the electromotive force Vbo, the current value (value Vbo/2Rb) when the battery output becomes maximum is set as the upper limit value of the optimal current range IR (S106). the DC/DC converter is driven/controlled by limiting the duty ratio D so that the current Ib is within the range of the optimal current range IR (S108, S110, S112). Thus, it is possible to appropriately convert the battery input voltage.
603 citations
Patent•
10 Oct 2008
TL;DR: In this article, a step-up voltage converter is configured to produce a high supply voltage at an output, which is coupled to the output of the high voltage circuit, and the controller selectively powers the low voltage circuit using either the output from the stepup voltage converter or the battery voltage.
Abstract: Embodiments of the invention are directed to a device that includes a battery having an output of a battery voltage, a step-up voltage converter, a high voltage circuit, a low voltage circuit and a controller. The step-up voltage converter includes an input that is coupled to the battery voltage. The step-up voltage converter is configured to produce a high supply voltage at an output. The high voltage circuit is coupled to the output of the step-up voltage converter. The controller selectively powers the low voltage circuit using either the output from the step-up voltage converter or the battery voltage.
449 citations
10 Jul 2006
TL;DR: In this paper, a simple analytical expression for the current stress on the DC-link capacitor caused by the load-side inverter of a voltage D-link-converter system is derived.
Abstract: A simple analytical expression for the current stress on the DC-link capacitor caused by the load-side inverter of a voltage DC-link-converter system is derived. The DC-link capacitor-current RMS value is determined from the modulation depth and by the amplitude and the phase angle of the inverter output current assuming a sinusoidal inverter output current and a constant DC-link voltage. Despite neglecting the output-current ripple, the results of the analytical calculation are within 8% of measurements made from digital simulation and an experimental system, even if the output-current ripple is relatively high as in the case of low-frequency IGBT inverter systems. The simple analytical expression provides significant advantages over simulation methods for designing the DC-link capacitor of PWM converter systems.
350 citations