Power Electronics
As a specialists in power electronics development and design, our centre supplies solutions for diverse applications such as motor control, traction, UPS, power generation, induction heating, welding, wind-power and electric vehicles. Top range applications include:
Inverters for radar servo controls
High speed BLDC, PMSM motor drives
High power four quadrant inverters
High frequency resonant converters
High efficiency power control engineering
SAC is providing innovative and high quality OEM solutions for measuring electrical parameters. Current and voltage transducers are used in a broad range of applications in industrial, traction, energy, automation and automotive markets.
Virtual prototyping
Our virtual prototyping (VP) encompasses a wide array of tools in order to facilitate the computer aided design (CAD/CAE) of contemporary and future engineering systems. The methodology gives an engineer or scientist a suite of tools whereby virtual experiments can be performed in software, in order to critically assess the behaviour of a system or component of that system. From simple analytical models to full three-dimensional finite element analyses, the virtual experiment can facilitate rapid parameter sweeps or optimization methodologies to inform considered design.
Our research, development and design (R&DD) of power electronics, transducers and transducer arrays has been proven in the field through a number of applications and practical examples. Deployment of search algorithms for multi-parameter optimization schemes of concept design and material selection has improved reliability and robustness of engineered solutions.
SAC researches and develops electronic components and systems that will overcome major technical barriers. The advanced power electronics activity focuses on:
Electric drive system for hybrid electric vehicles
Modular electric machines
Complex control algorithms
Electric assistance to internal combustion engines
Kinetic energy recovery systems (KERS)
Engineers focus on developing advanced power electronics and electric machinery technologies that improve reliability, efficiency and ruggedness and dramatically decrease systems costs for advanced vehicles. To accomplish this, the power electronics team investigates cooling and heating of advanced vehicles by looking at the thermal management of motor controllers, inverters and traction motors with one- and two-phase cooling technologies.
We also work to advance key components and systems for these vehicles, such as power switches, capacitors, and active filters within the inverter, which condition the transfer of power between the power generation unit (a fuel cell, flywheel or battery) and the electric motor.
Intelligent Power Processing
We achieve higher efficiency power conversion through “intelligent” power processing and assured thermal stability via thermal management. We also ensure appropriate operation and lifetime/reliability via mechanical/structural stability of components, modules and total assembly.
To take full advantage of the latest technology in motors and generators, we utilize state of the art components in motor drives and inverters. Whether developing, integrating or manufacturing the necessary power electronics, we always design with the system in mind. From looking at the effect of current harmonics in motors or generators to the most suitable power electronics topology for specific application, We custom design and manufacture electronics for niche applications in various industries.
SAC is following and utilising trends in power conversion technologies such as:
Soft Switching
Full integrated multilayer PCB packaging concept
Synchronized rectification
Intelligent power processing
Planar magnetic structures
Robust capacitors with minimised DC bus capacitance
Digital control and digital assisted power conversion
Heat management
EMC management by minimization of the parasitic elements in the circuit
Integrated Modular Motor Drives
We use permanent magnet motors from low to high speed applications, making them well suited for a wide range of applications, designs that operate with 30,000 to 100,000 rpm being the typical operating range for our power electronic drivers. Permanent magnet motors offer very high power density for minimum size simplifying system integration. The high efficiency of these motors also maximizes the overall system efficiency. Offered in air-cooled or liquid-cooled versions, these machines offer the latest technology in high strength rare earth materials for very high power density (minimum size) and very high efficiency.
Our motor drive architecture has been defined as offering promising long-term opportunities for reduced cost and increased reliability. This is achieved by emphasizing modularity and integration of the drive components. The resulting integrated motor-converter eliminates the need for a separate drive electronics box as well as the wires and connectors between the motor and the electronics.
Modular phase-drive units can be implemented as active intelligent power electronics modules with integrated current and temperature sensors, offering opportunities for standardization and high-volume production to reduce future drive costs. In addition, the modularity makes it possible to design a motor drive which continues to operate when one or more of the phase-drive units fails, improving overall drive reliability.
SAC is part of the modern era of soft-switched converters for alternating current (AC) motor drives. Most of the harmful effects of hard switching are eliminated by using the soft-switching principle in a high-frequency resonant link power conversion system. The input DC/AC power is first converted to high-frequency AC (tens of kHz) and then reconverted to variable voltage, variable frequency (VVVF) AC for driving the AC motor.
However, there are many applications that demand economical and lightweight transformer coupling through a high-frequency link because of the advantages of galvanic isolation, noise decoupling, voltage level transformation and auxiliary power supplies. In such applications, a soft-switched converter system is justified because the inherent advantages of soft switching are added automatically without any additional circuit complexity. Between the resonant link and nonresonant link systems, the latter has the advantages of easy soft-switching capability, high-quality link voltage wave and stable link frequency which permit synthesis of improved output voltage waves. As the device cost decreases further and there is more integration of the converter system, the high-frequency nonresonant link system for an electric/hybrid vehicle drive is expected to find increasing acceptance for general applications.
“By-wire" technologies will be required to implement in-wheel motors on all four wheels.
“The electronic traction" system has been one of its kind for application in commercial vehicles in terms of in-wheel direct drive motor technology for use in conventional and hybrid vehicles.
Hybrid electric vehicles have gained increased popularity in recent years as consumers look for alternative fuel vehicles to conserve energy and reduce CO2 emissions. Electric motors are more energy efficient than conventional combustion engines running on gasoline and they can dramatically reduce emissions.
Manage high frequency (HF) parasitic resonances just after semiconductors commutation, between
MOS capacitance and transformer stray inductance
Balance inductance reduction with capacitance increase
Chose and design EMC optimized power converters (from 100W up to few 100kW)
Avoid expensive shielding and improve reliability by electromagnetic integration of passive components
At higher switching frequences, conventional circuit theories with localized constants like “parasitic capacitances” or “stray inductances” need to be improved with a physical understanding of the electromagnetic propagation in and around the power circuit. SAC is using time domain reflectometry (TDM) to characterize and optimize power electronics system interconnect parasitics.
