Executive Officer, Group President, Energy & Industrial Systems
As a provider of a full range of equipment and systems that support power systems from power generation and conversion to transmission and distribution, the Energy & Industrial Systems Group recognizes that achieving a sustainable society is a global issue today. Based on this, we are developing high-performance equipment with the aim of eliminating or reducing the use of SF6 gas, which has high global-warming potential. These products include high-efficiency power generators, switchgear, and transformers. We are also pushing forward with the development of monitoring and control systems, smart meter systems, and battery energy storage systems that contribute to the realization of "high-quality power distribution systems with economy and reliability." Furthermore, we are working to "optimize energy use by utilizing ICT* to realize interconnectivity" and to contribute to the realization of a "resilient energy infrastructure that operates seamlessly, even at times of emergency."
Moving forward, we are also working on the development of power stabilizing equipment and systems capable of responding to new demand. This includes promoting expansion of the nuclear power generation business based on the energy policies of each country, supply and demand management with the growing use of renewable energy, integrated management including demand control of distributed energy sources, and supply and demand management by interconnecting electric-power utility companies.
In terms of reducing the impact of our business on the environment, we will contribute to the creation of a "safe, secure, and comfortable sustainable society" through ongoing initiatives to reduce the energy used in our production and testing processes, and to ensure the strict management of chemical substances.
Focusing on the SDGs
Against the backdrop of the globally increasing call to reduce the negative environmental impact of CO2 emissions and other harmful substances, there is now growing demand for turbine generators that are capable of higher performance, including improved efficiency and higher reliability. In response to these needs, Mitsubishi Electric has successfully developed the VP-X Series of high-output/high-efficiency indirect hydrogen-cooled turbine generators and introduced models up to the 900 MVA class*1.
Compared to water-cooled systems, indirect hydrogen-cooled generators have the advantage of not requiring auxiliary equipment such as stator cooling water feeders. Our VP-X Series generators expand the application of high-efficiency indirect hydrogen-cooled systems to the high-output range of 900 MVA, which was the realm of water-cooling methods until now. We expect these new generators to offer various advantages in terms of operation and maintenance.
In addition, several new element technologies that enhance output, improve efficiency and reduce size were discovered during development of the VP-X Series, and can be applied to the partial renewal of existing generators. We are also providing customers with a new line of upgrade services, and hope that this will help us meet diversifying requirements for improving the performance of existing equipment.
High-efficiency VP-X turbine generator
870 MVA generator for verification testing
With the goal of reducing greenhouse gas emissions, we are promoting the widespread use of 70 kV-class cubicle-type gas-insulated switchgear (C-GIS) equipped with a vacuum circuit breaker that uses no SF6 gas thanks to a dry-air insulation technique. We developed a gas-insulated circuit breaker (GCB) series that utilizes a spring mechanism instead of the conventional hydraulic mechanism and thereby significantly reduces maintenance work and minimizes energy loss. We have completed commercialization for products up to 500 kV and are now working on minimizing material consumption and operating power, as well as extending the service life of the equipment.
Cubicle-type gas-insulated switchgear
Gas circuit breaker
We supply a number of customers in Japan and overseas with transformers that operate at higher efficiency while generating less heat and thereby contribute to reducing transmission power loss from the plant to the customer, as well as to reducing CO2 emissions. We are also developing compact transformers in order to reduce the volume of materials used. In addition, for rolling stock, we have developed and delivered natural-air cooling transformers that use an airflow generated by the running train to cool the transformer. As the system uses high-efficiency transformers that generate less heat and are cooled by airflow alone without employing an electric fan, a significant contribution to energy conservation is realized.
On-board transformer (for rolling stock)
Over the past 30 years, Mitsubishi Electric has been contributing to the advanced operation of power systems by supplying various power electronics technologies and products for the electric power industry in support of power distribution networks. In recent years, we have been focusing on developing and enhancing battery energy storage and DC power distribution systems with the goal of expanding business related to smart grids and VPP systems, which are expected to be effective measures against climate change.
By connecting energy sources located in various places (distributed energy sources) such as power generation facilities using renewable energies and batteries, a virtual power plant (VPP) system with a supply capacity equivalent to that of a single power plant in a power system can be constructed. The utilization of such systems having CO2-free power sources can supplement power supplies and help create a low-carbon society. They can also help to solve power system stability issues caused by the unreliable nature of power generation using renewable energies. Mitsubishi Electric provides the control and interface technologies and manufactures various equipment required for the utilization of VPP systems.
We offer an integrated service, from the development of the latest, high-capacity low-loss power devices to the construction of systems for large-scale electric power facilities. In order to improve flexibility in electric power operations and solve various problems in electric power systems, highly sophisticated power electronics technologies are applied. We will continue to contribute to building power distribution facilities that support the foundation for the realization of smart grids.
Smart meter systems will be the core component for electricity deregulation of retail sales. Information about when and how much electricity was used will be indispensable to allow consumers to freely select an electricity supplier. We have developed a system that enables large volumes of meter data to be collected accurately at low cost, and this system is now being used in the operations of several utilities. In addition, these smart meter systems are capable of providing as much electric power as required in real time for individual users' power-/energy-saving actions via alternative channels.
Battery storage systems are essential for the flexible operation of power systems. These systems are the key to balancing power generation when using renewable energies, for which output fluctuates, and power generation using fossil fuels. We have installed battery energy storage systems for small-scale power systems in locations such as remote islands, and testing is in progress. Battery energy storage systems are also helpful as a countermeasure for the excess power or fluctuations that result from using renewable energies in a main power grid system. Mitsubishi Electric is focusing on expanding products that take full advantage of renewable energies such as wind and solar power without restricting outputs, and is contributing to the realization of a low-carbon society and the stable operation of power systems.
We have produced the next-generation DC distribution system D-SMiree, which contributes to alleviating concerns regarding the environment, resources and energy through energy savings, energy creation, and energy storage. By proposing a DC distribution method rather than the conventional AC distribution method, we can achieve energy savings (reduction of conversion frequency), energy creation (optimal interconnection of multiple power generation sources, including solar and wind power), and energy storage (optimal charge and discharge control of storage batteries by leveraging an energy management system). This will contribute to the change from an energy-consuming society to an energy society based on local production for local consumption.
Demonstration facility exterior
Demonstration facility electrical lab
This monitoring and control system achieves even higher functionality and performance than conventional models, reduces volume and weight by up to 30%, and contributes to resource and space savings. It also reduces power consumption by up to 33% compared to conventional systems. In addition, the CPU card and I/O unit are designed to be compatible with previous-generation hardware. Enabling the system to be introduced with minimum equipment updates reduces the impact on the environment, including the volume of resources used.
Demonstration facility exterior
While traditional models had a unit construction where a control board was housed in a card slot, the latest models adopt a module construction where the control board is integrated in the main body. This enables the size of the AVR to be reduced to one-fifth compared to that of previous models. With maintenance made easier and environmental impact at the time of manufacturing reduced, power consumption has also been halved. In addition to providing AVRs to power generation plants in Japan, Mitsubishi Electric delivers them to power plants around the world, contributing to the stable supply of electricity.
Card slot-type (previous model)
Module-type (latest model)
In addition to contributing to society through our business operations, we are striving to reduce the negative environmental impact stemming from our business activities. Some of the initiatives we are implementing are as follows.
The Energy & Industrial Systems Group's manufacturing bases (four at Mitsubishi Electric, seven among affiliates in Japan, and two among overseas affiliates) manufacture equipment in small lots, including large generators and transformers. They also produce medium-sized equipment and system devices through small-lot production, and manufacture components, assemble products, and perform testing for plates, machine work, and insulation materials. Each factory pays particularly close attention to preventing air, water, and soil pollution since they handle chemical substances and insulating oil. These factories also use great amounts of energy because of their large furnaces, cleanrooms, hot-water baths, and testing facilities. As a result, each is taking steps to reduce CO2 from production by systematically installing solar power systems, electrifying steam-powered equipment, and conserving energy by reusing factory exhaust heat. They are also promoting activities that minimize the emission of SF6 gas.
At the Power Distribution Systems Center (Kagawa Prefecture), we are focusing on initiatives for preserving biodiversity. The creation of biotopes and installation of rooftop greening louvers are part of those activities. In addition, as part of our efforts to nurture environmental awareness and social contribution, we are proactively pushing forward with Satoyama Woodland Conservation activities. In recognition of these activities, the Power Distribution Systems Center received the "SEGES Excellent Stage* 1" certification implemented by the Organization for Landscape and Urban Green Infrastructure, as the first achievement by Mitsubishi Electric Works and in the Shikoku region.
The Energy & Industrial Systems Group is working to raise the effectiveness of its environmental initiatives by having environmental managers from Mitsubishi Electric's works and affiliates become involved in various ways, such as by participating in environmental promotion conferences and conducting energy conservation inspections at affiliate companies.
Audits were conducted at the Energy Systems Center (Hyogo Prefecture), Transmission & Distribution Systems Center (Ako District, Hyogo Prefecture), Power Distribution Systems Center (Kagawa Prefecture), Heat Exchanger Works of Tada Electric Co., Ltd. (Okayama Prefecture), Headquarters Plant (Hyogo Prefecture) and Asahi Works (Aichi Prefecture) of Ryosan Industry Corporation, and Ryoden Kasei Co., Ltd. (Hyogo Prefecture).