The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper introduces a new modulation scheme for a Modular Multilevel Converter incorporating the selection of inter-phase module inductance chosen so its resonate frequency is sufficiently higher than both the switching and AC output frequency of the M2LC converter.
The battery energy storage systems (BESS) using modular multilevel converter (MMC) as the grid interfacing converter could integrate multiple independent battery stacks with flexible control capability by assuming the unique circulating current control scheme. Traditionally, the separate battery stacks in MMC are controlled to have the same state of charge (SOC) for maximizing the operational capacity,...
The AC side Single Line to Ground (SLG) fault is one of the most frequent faults in power systems. And, in an HVDC system based on modular multilevel converter it calls for the fault ride through strategy to transmit maximum possible electricity during the fault to secure power system stability. It presents different characteristics of SLG faults at the voltage regulator side and the power dispatcher...
MMCs are normally designed to operate in the linear region of the PWM. This limits the peak-to-peak phase voltage in the AC port to be lower than the DC port voltage. It is possible to increase the AC voltage beyond this limit by the use of overmodulation strategies. However, this is at the price of an increase in the harmonic content (THD) of the voltages and currents, and consequently, of a decrease...
Conventional MMCs use cells which typically consist of a half-bridge and a capacitor. Due to their limited energy storage capability, the net power balance of the cells is zero (neglecting losses), the MMC therefore realizing a bidirectional power transfer between its DC and AC ports. It is possible however to provide the MMC with the capability to transfer power at the cell level. The use of such...
A new AC/AC multilevel converter topology suitable for high power applications is presented. The proposed topology has less number of IGBT switches and capacitors compared with traditional approaches. In addition, more than half of the switches are operating in soft switching condition, which considerably decreases the switching losses. The theoretical calculations and simulation results are provided...
A DC/DC Modular-Multilevel Converter (MMC) is proposed in this paper, in which two modular multilevel converters are linked by a LCL tank. With the proposed converter, the high power medium frequency transformer can be eliminated to simplify the structure, quasi zero-current-switching operation of both MMCs can be achieved to alleviate the switching loss, the voltage stress of internal LCL tank can...
The modular multilevel converter (MMC) is a competitive candidate for medium/high-power applications, specifically for high-voltage direct current transmission systems. Model predictive control (MPC) is an advanced and flexible method for power converters. The existing MPC methods for the MMC 3-phase system treat whole system as a three independent single phase system, and the computational load increases...
Modular Multilevel Converter (MMC) has recently become a popular multilevel topology for high-power applications. Conventionally, the circulating current between the legs of an MMC is an unwanted current that must be minimized in order to reduce the converter loading. In this paper the impacts of the circulating current in the MMC to the current ratings of power semiconductor devices are comprehensively...
Small-signal state-space analysis of power system stability relies on linearized models where steady state operation corresponds to constant values of all state variables. Such models are available and commonly used for analysis of configurations with three-phase 2- or 3-level Voltage Source Converters (VSC). However, the Modular Multilevel Converter (MMC), which is emerging as a preferred topology...
The modular multilevel converter (MMC), eliminating the expensive and bulky multi-winding phase-shifting transformer compared with the cascaded H-bridge converter, is shown to be of great potential in the field of medium-voltage motor drive applications. However, special care needs to be taken for MMC driving motor at low speeds, since the voltage fluctuation of the submodule capacitors increases...
In recent years, the Modular Multilevel Converter (MMC) has gained a lot of interest in industry due to its modularity and scalability for different power and voltage levels. However, the control of a MMC consisting of several submodules is often implemented in a central control system, so that the whole MMC system cannot be considered as modular. The thought to distribute control tasks to each submodule...
There are several problems in the Modular Multilevel Converter (MMC), such as the appearance of circulating current, capacitor voltage unbalance and the requirement for a high number of sensors. All these problems will decrease the reliability and raise the cost/uncertainty of using MMC solutions. As a result, a sensorless control method is proposed in this paper, which targets to improve the performances...
This paper introduces a new concept for offshore wind turbine electrical architectures for wind farms with MVDC collection grids. With the proposed pre-transformer wind turbine drivetrain arrangement, the AC output of the wind turbine generator is transformed to a higher voltage by a step-up transformer and then rectified to a corresponding DC voltage by an active ac-dc converter. A modular multilevel...
This paper proposes an integrated power conversion system in electric vehicle using modular multilevel converter, whose modular structure could manage the integrated battery cells to simplify the traditional battery manage system (BMS) meanwhile provide the motor driving function and battery charging function without using additional hardware. The all-in topology could therefore maximize the capacity...
This paper employs the sensitivity analysis technique to develop a modular multilevel converter (MMC) model that provides a guide for how the design should be carried out. There are several design criteria that it is necessary to take into account when designing a converter. In the case of the MMC, these criteria are a function of many variables. The sensitivity analyses guide the modeling effort,...
Recently, dc-dc modular multilevel converter (MMC) with medium or high frequency transformer has attracted more and more attentions for its many advantages such as flexible dc power flow control, good voltage matching and inherent dc current limitation. So far, the arm-voltage of dc-dc MMC has been modulated in many forms such as sinusoidal, trapezoid or even rectangular to gain different benefits...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.