Suggestion and feasibility study for a massively parallel back‐to‐back system

Abstract

SUMMARYThis paper presents a new concept for back-to-back (BTB) dc systems. The main feature of the proposed BTB is referred to as massively parallel. This massively parallel BTB system consists of a number of small-or mediumcapacity inverter units that are connected in parallel. The concept of transmission power control using the massively parallel BTB is investigated using MATLAB for a case where a fault occurs. In addition, a method for modeling the proposed BTB in EMTP is investigated. The work presented in this paper shows that the proposed BTB system is very promising for large power system applications because the losses of the system are very small compared to conventional BTB using VSC (voltage source converter). The massively parallel BTB can keep operating even if an inverter unit fails, thus improving overall power transmission capability. © 2001 Scripta Technica, Electr Eng Jpn, 138(3) : 3442, 2002

An Electromagnetic Transient Simulation Model of Grid-connected Inverters for Dynamic Voltage Analysis of Distribution Systems

“…The VAve model [7][8][9][10][11][12] has been developed to allow for the EMT simulation of inverters with a large time step. The inverter F I G U R E 3 Configuration of the VAve model is modeled by voltage sources that output reference voltages, and connected to the AC system without simulating switching operations and PWM.…”

“…Then it was also applied to power system analyses, and a number of average-value models for voltage source inverters were developed. [7][8][9][10][11] The method was further extended to simulate the inverter's gate-block operation 12 ; that method can deal with both operation and stop conditions. In this paper, we refer to that model as the voltage average-value model (VAve model).…”

An electromagnetic transient simulation model of grid‐connected inverters for dynamic voltage analysis of distribution systems

“…The VAve model has been developed to allow for the EMT simulation of inverters with a large time step. The inverter is modeled by voltage sources that output reference voltages, and connected to the AC system without simulating switching operations and PWM.…”

“…The averaging method (a method in which voltages and currents are dealt with their averaged value over one switching period) was originally employed in analyses and control system designs of power electronics circuits. Then it was also applied to power system analyses, and a number of average‐value models for voltage source inverters were developed . The method was further extended to simulate the inverter's gate‐block operation; that method can deal with both operation and stop conditions.…”

High-order harmonic resonance phenomena of a voltage-sourced converter in cable system

“…STATCOM (Static Synchronous Compensator), UPFC (Unified Power Flow Converter), and other devices of FACTS (Flexible AC Transmission Systems) have been developed both in this country and abroad, aiming at flexible operation of power systems and efficient utilization of existing transmission equipment [1][2][3][4][5][6]. In the United States and other countries, such devices have been widely introduced owing to the necessity of voltage control and power flow control in the deregulated power market [7][8][9][10].…”