I. Product overview

Turn-to-turn short circuit of generator rotor windings is a common fault in power systems. When such a fault occurs, the rotor current increases and the winding temperature increases, limiting the output of the generator, and in severe cases, it will affect the normal operation of the generator. Turn-to-turn shorts are usually identified by measuring the AC impedance and power losses of the generator rotor windings. The traditional measurement method is to use multiple test instruments and measure them after they are assembled in the field. This method, which requires a lot of test instruments to set up a measurement system, has the disadvantages of cumbersome test equipment, time-consuming and laborious, complicated data sorting, and low measurement accuracy.

With the continuous development of digital signal processing technology, new microprocessors and algorithms are constantly emerging. Based on this, we have developed a generator rotor AC impedance tester based on digital signal processor DSP. The instrument takes the digital signal processing system as the hardware platform, which gives full play to the computing power of the digital signal processor, which greatly improves the calculation speed and calculation accuracy of the instrument, and provides a guarantee for the normal operation of the power system.

II. Features

l Fully automatic (manual) collection, measurement, display, storage and printing of all measurement parameters and AC impedance characteristic curves;

l Real-time display of measurement data and AC impedance characteristic curve, convenient for storage and printing;

l Using 320×240 large-screen LCD display, Chinese menu prompts, easy to operate;

l Built-in large-capacity non-volatile memory: can store 200 sets of measurement data and curves;

l Built-in high-precision real-time clock function: date and time calibration can be performed;

l Built-in high-speed micro thermal printer: can print measurement and historical data;

l Concurrently perform no-load and short-circuit tests of single-phase transformers and volt-ampere characteristic tests of voltage (current) transformers and arc suppression coils;

l It has perfect overvoltage and overcurrent protection functions, among which the overvoltage and overcurrent protection value is automatically adjusted according to the setting of the test parameters, which is simple and can ensure the safety of the tested equipment.

III. Technical parameters

Measurement range   Impedance:0～999.9Ω

                                   Voltage：0～600V

                    Current：0～120A

                    Power：0～72kW

                    Frequency：45～65Hz

Accuracy:   Impedance, voltage, current, frequency:0.2 class

Power: 0.5 class

Dimensions:   345mm×295mm×175mm

Instrument weight:   5kg