Exploring software defined power electronics
What is software defined power electronics?
The development of custom embedded firmware, alongside standard control electronics and power electronics hardware, facilitates the swift creation of new applications.
The three-phase, six-switch circuit is used in variable speed drives, grid-tied and grid-forming inverters, and stand-alone inverters. While the application layer firmware distinguishes these uses, they all utilize the same power and control electronics.
The control electronics include an MCU, MMI, gate drivers (MOSFET/IGBT/SCR), voltage, current, and temperature sensors, and an auxiliary voltage regulator to power the electronics.
Software-defined power electronics utilize a standardized control hardware platform that can be applied to various power circuits and applications. This is supported by embedded firmware infrastructure and standard power electronics components, including half bridge, H-bridge, and three-phase bridge circuits, as well as standard SCR circuits like AC/AC controllers and AC/DC rectifiers.
What does the standardized control hardware platform look like?
It includes the entire signal chain, from sensors for voltage, current, and temperature to the MCU with gate driver outputs. This covers widely used MCUs like STM, Texas, and Arduino cards that connect to the control motherboard.
What comprises the power electronics platform?
The power electronics include the power components, voltage, current and temperature sensors, as well as the gate drivers (MOSFET/IGBT/SCR).
We begin with low power applications, in which the power electronics are integrated onto a printed circuit board, and conclude with heat sink stack assemblies where the power semiconductors are affixed to aluminium heat sinks. Typically, the transition occurs at approximately 10kW and 600V-800V.
What are the benefits of software defined power electronics?
In summary, the process involves quickly developing a new application by utilizing existing control and power electronics while only creating the embedded firmware application layer. The lower embedded firmware layers are designed to be configurable and reusable.
Where are software defined power electronics used?
Custom applications, such as motor drives, grid tied and grid forming inverters, DC/DC converters, battery chargers and other custom applications.
Power converter circuits include half bridge, full or H-bridge and three phase bridge circuits based on PWM switching. As well as SCR circuits include AC/AC and AC/DC phase control. Various multilevel converter and inverter circuits are also covered. Power electronics for new custom applications can easily be developed.
The power range goes from around 1kW to hundreds of kW, and the voltage range includes the low voltage range below 1kV.
Numerous commercially available power electronics stack assemblies can significantly reduce development time. The range of options is extensive, including products from Semikron Danfoss and Wolfspeed. By integrating these with our standardized control electronics hardware and firmware, development timelines can be shortened to weeks rather than months or even years.
What does the control electronics look like?
The flagship control electronic platform in the Power Electronics Development Kit (PED-Kit) range features a card-based design with a backplane and plug-in cards. The plug-in cards include MCU cards supporting STM, Texas Instruments, and Arduino MCU cards, digital and analogue I/O cards, as well as specialized power electronics cards such as IGBT, MOSFET, and SCR gate drivers, pre-charge control, relay cards, voltage sensor cards, and temperature sensor interface cards. Current sensors are typically mounted on the power electronics and provide signals to the analogue inputs. This version of the PED-Kit is designed for applications using heat sink assemblies and high-power scenarios, ranging from tens to hundreds of kW. It also includes an MMI with an RS422 interface and various communication options like Ethernet, RS422/RS485. Extensive analogue and digital I/O capabilities are provided to enable process-based control and monitoring beyond power electronics. Applications include motor drives and electromagnet controllers that require additional I/O functionalities.
(Photos of PED-Kit inserted here, include photo of the PED-Kit in the black box and on its own)
The next product in the PED-Kit range is a smaller version, featuring a motherboard with parallel plug-in cards, unlike the previous version which had vertically oriented plug-in cards. The same hardware cards are available, including voltage sensors, temperature sensor interfaces, MCU cards, digital and analogue I/O, and an MMI. This version of the PED-Kit is compatible with heat sink stack-based power electronics as well as printed circuit board power electronics. Customization is achieved through firmware, and if necessary, a custom motherboard can be developed easily.
The third option combines multiple converters/inverters into a power system using custom motherboards with standard plugin cards. This approach is suitable for applications like step-up inverters, battery chargers, and PV regulators.