Built in Three-Phase Inverter Power Supply: Without Voltage Regulator, It Can Also Measure Three-Phase Transformers on Site

In the past, when conducting transformer short-circuit impedance tests, a three-phase voltage regulator had to be prepared on site - it was bulky and heavy, and some remote substations could not be moved in at all. The design of HZ2611 with built-in three-phase inverter power supply has completely changed the operation mode of on-site testing.

Pain points of traditional methods

The external power supply solution for traditional short-circuit impedance testing requires a three-phase voltage regulator (usually weighing tens of kilograms) to slowly adjust the voltage from zero, while equipped with independent instruments such as voltmeter, ammeter, and power meter to collect data separately, and then manually calculate Uk%. The entire set of equipment usually requires two to three people to operate, and transportation and on-site layout take a long time.

For sites without three-phase power supply (such as temporary testing points in the field and some old factories), it is even impossible to complete short-circuit impedance tests for three-phase transformers.

Solution for HZ2611

HZ2611 only needs to be connected to single-phase 220V mains power, and the built-in three-phase inverter power supply automatically converts it into three-phase AC output, providing adjustable voltage directly to the high-voltage side of the short-circuit test. No external three-phase power supply or voltage regulator is required. The instrument body integrates all functions of power regulation, data acquisition, calculation, and display.

When using the built-in inverter power supply, the instrument defaults to three-phase four wire (three watt meter method) testing, with the highest accuracy. Three phase data is synchronously collected, vector graphics are displayed in real-time, and the operator can start with one click on the 7-inch touch screen. After the test is completed, the parameters are automatically calculated and displayed, and one person can complete the operation throughout the process.

Matching of voltage and current ranges

The voltage measurement range of HZ2611 is 0-20V phase voltage, and the current range is 0-2A. This range is designed for the low test voltage scenario applied on the primary side in low-voltage short-circuit tests - at this time, the applied voltage is only a few percentage points of the rated voltage, so the absolute voltage value is not high, but it requires extremely high accuracy.

The measurement accuracy of the instrument reaches 0.2% within the range of power factor 0.2-1.0, and can maintain 1% accuracy even when the power factor is as low as 0.01, covering the short-circuit impedance testing requirements of most transformers (including large transformers with extremely low power factors).