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products & services
products & services
Precision power analysis High-precision, real-time measuring is helping to further the quest for efficiency in electrical and hybrid variable-speed drive systems Structural diagram of the Hioki flux gate current sensor that achieves both high precision and wide bandwidth characteristics
As technologies for electrical and hybrid vehicles advance, with demands for even greater improvement in efficiency, there is a need for a power analysis system that is better suited for developing and testing low-loss, high-efficiency variable-speed drive systems. Besides automotive applications, systems that can measure loss and efficiency with a high degree of precision and in a stable manner also play an important role in the development and testing of devices such as PWM inverters, DC/DC converters, and motors that are used in such systems. Device loss and efficiency are calculated by simultaneously measuring the input and output power of the target device and then dividing the results to obtain a ratio. Electrical power is measured using voltage and current, while mechanical power is calculated based on torque and RPM. Measurement systems must deliver the performance to simultaneously measure these dynamically changing parameters in a stable, highly precise manner and calculate the results in real time. In addition to a level of DC measurement performance that is characterized by the lack of any offset drift even if the temperature changes, power analyzers used to measure current must provide highprecision coverage of PWM switching frequencies and the ability to measure large currents in excess of 100Arms. However, current probes that use standard shunt resistors, current transformers (CTs) or Hall elements are unable to deliver this level of performance. The optimal method is to use a high-precision current sensor that uses the zeroflux method instead of Hall elements to deliver wider bandwidth. Hioki has a solution in the 3390
Analysis of the leakage magnetic field of split core sensors
Power Analyzer. Designed to serve as a single-instrument solution, it provides four voltage and current inputs that can simultaneously measure the DC and PWM sides of a target device, as well as torque and RPM signal inputs, and immediately calculate loss and efficiency at high speed (as fast as every 50ms) using completely synchronized measured values.
01 // July 2014 // Electric & Hybrid Vehicle Technology International
The CT6843 sensor is DC to 500 kHz/200A, ideal for capturing signals during the efficiency testing of batteries, inverters and power conditioners
The power analyzer combines current inputs that are optimized for use with high-precision current sensors and can also supply current to sensors, and can accept frequency-based torque so that it can accommodate output from high-precision torque sensors. The power analyzer delivers active power accuracy of 0.05% at 50Hz, 0.2% at 10KHz and 1.5% at 100KHz, and provides highprecision coverage for the PWM frequency domain. Developers can mix and match current sensors from 50W class to
Waveforms sampled at a high speed of 500kS/s
500kW class devices according to the needs of their applications, and can choose from a selection of high-performance models that combine flux-gate and zero-flux designs that have been a staple of Hioki’s current sensor lineup since 1994. Performance-oriented passthrough variants are available with ratings ranging from 50A to 1,000A, while convenience-focused clampstyle sensors are available with ratings from 20A to 200A. The Hioki 3390 Power Analyzer also provides functionality for analyzing an IPM motor’s d-q axis
control state based on electrical angle data, while it simultaneously measures motor efficiency. By serving as a one-stop solution for mapping the relationship between current phase control and efficiency, the high-precision instrument promises to help engineers improve the performance of tomorrow’s state-of-the-art power drive systems. FREE READER INQUIRY SERVICE To learn more about Hioki, visit: www.ukipme.com/info/ev
Inquiry no. 538
Electric & Hybrid Vehicle Technology International // July 2014 // 02
HIOKI POWER ANALYZER AND CURRENT SENSORS
Delivering the best solution for high precision testing of power efficiency and loss across high currents and wide bandwidths for the research, development and testing of electric vehicles. HIOKI - the world’s only developer and manufacturer of current sensors and power analyzers to offer 0.05% accuracy when measuring variable frequency drives ranging from 50W to 500kW.
HIOKI E.E. CORPORATION 81 Koizumi Ueda, Nagano Japan 386-1192
www.hioki.com +81-268-28-0562 ev@hioki.co.jp