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Digital Grid Routers (DGR)

Overview

Digital Grid Routers (DGR) are intelligent electrical power control devices that make it possible to receive or send electricity in accordance with commands from external controllers. By forming an asynchronous interconnection with the power grid, DGRs are able to avoid imparting the fluctuation of the output of renewable energy sources under their control to the grid, contributing to the expanded use of renewable energy. DGRs also allow electrical systems under their control to operate independently when the power grid is down.

Digital Grid Routers (DGR)

Basic Principles

Trait 1: Asynchronous Interconnections with the Power Grid

When conducting electrical power interchanges, digital inverters are used to conduct a BTB (Back to Back) process, inverting electricity from AC to DC, and then back to AC again. This eliminates the usual challenge of voltage and frequency synchronization when connecting renewable energy source systems to the power grid. This, in turn, makes it possible to utilize renewable energy power sources without their output fluctuations affecting the grid. Further, having three or more terminals allows connections between cells (DGR and micro grids consist of demand facilities, distributed power sources, etc.) to be increased freely.

Trait 1: Asynchronous Interconnections with the Power Grid

Trait 2: Voltage/Current Control

DGRs have terminals for connecting to the grid, demand facilities, distributed power sources (solar power, etc.), storage batteries, and other DGRs and are capable of freely controlling the inputs and outputs between any of them.

Trait 2: Voltage/Current Control

Trait 3: Electricity Identification

Each DGR is assigned a network address, and each of its terminals has a sub-address. In the event that an electrical power interchange is conducted between multiple DGRs, a record of each transaction detailing which address the electricity came from, which address it was sent to, and how much electricity was sent is instantly created. This is the electricity identification function performed by DGRs. In recent years, Blockchain technology has been incorporated into this identification function in order to increase security.

Trait 3: Electricity Identification

Trait 4: Limiting the Effects of Grid Accidents

Because DGRs are capable of utilizing cells with distributed sources simultaneously with grid power, cells can independently form a power demand and supply system. This isolates them from the effects of grid accidents. By utilizing this system, the scope of grid accidents can be limited.

Trait 4: Limiting the Effects of Grid Accidents

Development History of DGRs

Before the founding of Digital Grid Corporation, prototype DGRs aimed at realizing the digital grid concept were created as part of a joint project between the University of Tokyo Abe Lab, Tateyama Kagaku Industry Co., Ltd. (one of our corporate investors), and other parties. Since then, we have conducted development aimed at the mass production of DGRs through a number of projects including pilot projects in which DGRs were installed at actual demands.

Development History of DGRs

Current State and Future

In FY2017, our proposal for a Low Carbon Technology Research, Development and Demonstration Program entitled “Digital Grid Router (DGR) and Power Interchange Settlement System to Accelerate the Introduction of Renewable Energy” was selected by the Ministry of the Environment. Since then, we have conducted development of DGRs aimed at miniaturizing and generalizing them for use in smart homes.

Digital Grid Routers (DGR)
Digital Grid Routers (DGR)

We are also looking to conduct development of systems that incorporate DGRs into electric vehicle rapid chargers in order to give people the ability to choose renewable energy sources, as well as development of DGRs capable of freely controlling the output of small-scale wind power plants.