To popularize smart energy equipment (solar power generation, wind power generation, electricity storage systems, electric vehicles, etc.), which is expected to grow rapidly, we commercialized general-purpose power converters using next-generation power semiconductors (SiC, GaN) for better conversion efficiency, more compact designs, and lower prices. We will create more market opportunities through globalization and horizontal specialization within the industry to popularize the smart energy equipment required by each country.
What is power electronics?
Power electronics technology is referred to as semiconductor power conversion technology, which is a technology commonly applied to systems centered on power conversion and control using power semiconductor devices. Power electronics can transform DC voltage (to a higher voltage or lower voltage) or converts DC to AC (inverter) through fast ON/OFF switching via power semiconductors. The technology can be used in a very wide range of areas: the electrical power sector for power generation and power distribution; industrial equipment such as motors and pumps; power supply units for communication systems, factories, and other facilities; the electrical railroad sector for train drive units and power transformation; automobiles; and electronic household products. A large number of sectors can conserve energy via the utilization of power electronics technologies. Recent demand for greater energy conservation and lower carbon emissions has led to growing expectations for the potential of power electronics technologies.
Power electronics technology is often described as a technological area where power, electronics, and control are unified.
Diverse technologies involved in power circuits, analog circuits, digital circuits, electric power engineering, electromagnetics, control engineering, microcomputer technology, and information and telecommunications technology are required for the development of power electronics products. In other words, the objective of power electronics technology is to pursue greater conservation of electrical power and energy by reducing power conversion loss in the use of those technologies.
How to convert electricity?
In power electronics, electricity is chopped by turning the switch ON / OFF. It is chopped into strip shapes, which are averaged and controlled to obtain a desired value. Here, we show an example of the waveform when DC electricity is converted into AC. The input DC electricity is chopped by turning the switch ON / OFF, and the output electricity is averaged to convert it into AC electricity.
What are the requirements of a power converter?
The requirements of a power converter are “high efficiency (energy saving)” and “downsizing.”
High efficiency involves improving the conversion efficiency of the power converter. If the efficiency is 95%, the remaining 5% is loss (heat). For example, Japan’s electricity consumption is about 1 trillion kWh. If the efficiency of power converters in Japan is improved by 1%, then the energy saving will be equal to the power generation of 1.4 nuclear power plants (10 billion kWh) ※1
※1：Assuming that 1 nuclear power plant with equipment capacity of 1 million kW operates at an operation rate of 70%.
On the other hand, with regard to downsizing, loss is one of the factors that determine the size of the power converter. In the case of 5% loss (heat) in the example above, a cooling device is needed to cool the 5% heat. For example, 5% loss of an inverter of 10 kW is 500 W, and in order to cool down the 500 W of heat, equipment such as a large fan or a heat sink is required. Reducing the loss will lead to downsizing of the equipment.
To realize “high efficiency” and “downsizing,” it is important to reduce loss, but how do we actually reduce the loss? The key lies in the switch (power device).
Many of the currently used power devices are made of Si. So far, Si power devices have maintained high performance through continuous improvement; however, they are now approaching the limit for improvement. Therefore, attention is currently focused on the next-generation power devices that utilize new materials such as SiC and GaN instead. As shown in the figure below, SiC-based inverters that can withstand high voltages are now being used in railroads, household appliances, and industrial equipment, while GaN, with its excellent high-frequency properties, is expected for use in power supply units for communications equipment.
Since SiC or GaN devices introduce considerably less loss in devices, when Si is replaced with SiC or GaN, the losses in the power device can be drastically reduced.
In addition, SiC and GaN can perform high-speed switching operations. Since the size of the reactor in a power converter is inversely proportional to the switching frequency, theoretically, when the switching frequency is increased by ten times, the size of the reactor can be reduced to 1/10.
Furthermore, SiC and GaN can operate at high temperatures of over 200 °C, which is the limit for Si power devices. Operating at high temperatures makes it possible to downsize or eliminate the need for a cooling device in a power converter.
Universal power conversion module with SiC / GaN
Although there is high expectation for next-generation power devices as described above, several issues still hindering their popularization. With extremely high switching frequency of the devices, a wide range of technologies challenges such as high-speed analog circuit technology, high-frequency measurement technology, high-frequency noise countermeasure technology arises, which the technologies are not yet in the field of power electronics so far. By introducing the high-frequency and high-speed signal processing technologies that beyond any category of the existing power electronics, Headspring has brought out the performance of next-generation power semiconductor by implementing easy-to-handle power conversion modules with these next-generation power devices. We propose a new solution called “Universal Power Conversion Module” that everyone can enjoy the merit of the next generation power semiconductors.
Strengths of Headspring
Our strengths lie in the ability to utilize libraries and tools filled with know-how peculiar to power electronics and to accomplish a design bridging the technical areas of power electronics; possessing the hardware / software that constitutes the power electronics equipment as standard technology assets and the ability to promptly construct a system; being able to achieve collaboration through our Open-Works style and accomplish any task at the highest speed.
1.Being able to utilize libraries and tools filled with know-how peculiar to power electronics and to accomplish a design bridging the technical areas of power electronics.
It is possible for us to bridge the gap between technical areas since we possess experience in “Gate Drive Technology” for designing the optimum circuit based on a good understanding of the characteristics of the device, “Software Design Technology” for operating the modules in a system, and “Standard/Certification Acquisition Support” for commercializing the system in each application area.
2.Possessing the hardware / software that constitutes the power electronics equipment as standard assets, and the ability to promptly construct a system.
The design of circuits and modules will change even if only a few parameters are changed, resulting in one design for one product, thus making the process time consuming. Since Headspring owns the standard assets of hardware and software in the company, it is possible for us to construct a system promptly by minor customization.
3.Being able to achieve collaboration through our Open-Works style and accomplish any task at the highest speed.
In attempting to create a unique value, we are as open as possible about the source of our expertise (Value-Out), thereby enabling the evolution of better solutions and practices together with external collaborators (Open-Works). That is our style. Please click here for details.
Development in Headspring
With abundant development accomplishments in a variety of different fields and development phases, Headspring provides development widely ranging from the system design of electricity storage systems, motor drivers, and power conditioners to the detailed design of gate drive circuits, control circuits, and sensor circuits.
Extensive knowledge for power conversion system design of power flow/noise
Gate drive circuit applicable to SiC, GaN, etc.
Development approach based on the theory applicable to circuit equations/control blocks.
Since we possess the technologies to solve the barriers to the development of power electronics under the condition where the circuits do not work correctly through simple replacement of conventional power semiconductors with new types, we can provide flexible proposals of advanced optimization, short development periods, and detailed design taking into consideration the entire system, regardless of the customer’s conditions.
Power Conditioner for Solar Cell
Electricity Storage System for Household
Charge/Discharge System for EV
Motor Driver for Robot
Instantaneous-drop Compensation Inverter System
Experiment Equipment for Power Electronics Education
Experiment Equipment for Reactor Loss Evaluation
Experiment Equipment for SiC-MOSFET Characteristic Evaluation
Experiment Equipment for GaN-HEMT Characteristic Evaluation