Computer-aided transducer calibration system for a practical power system

The paper describes a new computer-aided automatic calibration system developed for the instrument calibration department of the Taiwan Power Company. One- or three-phase power transducers, including voltage, current, watt, VAr and power factor transducers, can be calibrated in this system. The generated calibration power condition is programmable. Its voltage/current amplitude and phase angle are adjustable between 0 V and 300 V, -10 A and 10 A, and 0° and 360°, respectively. A 386 personal computer controls all the operations inside the calibration system and interfaces with users. A menu-driven, user-friendly software interface has been developed to support the system. It offers the user flexibility of operation and ease of usage. The IEEE-488 interface bus is connected in closed-loop mode to control all stimulated equipment and the transducers under test. Special emphasis is placed on the user friendliness of this computer-aided calibration system and its capability of calibrating ten transducers using only one set-up. The experimental results for various transducers are given, and the uncertainty of the system is discussed