Engineers who do relay protection debugging know that relay protection testers are the core tools for on-site testing. But why use "six phases"? Isn't three-phase enough? This question is very practical. If you answer it clearly, you will understand what problem the six cameras have solved.

Limitations of three-phase tester

The traditional three-phase relay protection tester provides three-phase voltage and three-phase current output, which is sufficient for simple line protection tests such as overcurrent protection, distance protection, and zero sequence protection. But once encountering transformer differential protection, trouble arises - the transformer has two sets of CTs on the high and low voltage sides, and differential protection requires injecting current to both sides simultaneously. The three-phase tester only has one set of three-phase currents. To measure the phase difference of A, IA needs to be connected to the high voltage side, IB needs to be connected to the low voltage side, and a compensation current IC needs to be connected. The wiring is complex, and when changing B and C phases, the wires need to be changed again, which is very inefficient.

The essential value of the six phases

HZJB-1200 provides 6 independent currents and 6 independent voltages, truly achieving simultaneous output of "two sets of three-phase currents". When conducting transformer differential protection testing, IA/IB/IC is fixedly connected to protect the high voltage side A/B/C, and Ia/Ib/Ic is fixedly connected to the low voltage side a/b/c. With one wiring and full phase testing, regardless of whether the transformer wiring method is Y/Y or Y/△, the wiring method is equally simple and does not require additional compensation current wiring skills.

Widely applicable

Six current channels can also be connected in three-phase parallel to increase single current to 60A, and six phase parallel can reach up to 180A, meeting certain high current testing requirements. The 6-channel voltage supports independent output of 6-phase voltage, which is used for tests that require simulating two independent system voltages, such as backup automatic switching and fast switching of plant power. The three-phase tester cannot perform such tests at all.

20 testing modules covering all scenarios

From basic AC/DC testing to distance and zero sequence protection, differential protection, line protection, impedance characteristics, and fault reproduction, the 20 testing modules of HZJB-1200 almost cover all types of relay protection and safety automatic device testing needs in the domestic power system. One device replaces multiple specialized instruments and is a standard configuration for modern relay protection professionals.