Optimal construction of secondary wiring of transformer station;

The existed secondary wiring method has some disadvantages such as the limited types of element which can be dealed with,the dissatisfactory optimization effect and the need of handiwork to generate terminal wiring diagram.

Application of anti-trip of the circuit breakers and secondary wiring of 2 trip coils is the wiring coordinated to the duplicated arrangement of protection.

Improvement on secondary connection of the voltage transformer to avoid magnetic resonance in 10 kV power supply system;

It proposes working voltage of zero-sequence differential protection and its secondary connection′s testing way.

A common mistake and its harm in CT secondary connection of transformer differential protection were analyzed,the correct connection mode was explaned,and how to use the hexagon vector diagram of checking was introduced.

So the way given by this paper is more useful that interlocking formulas can be built by a primary wiring diagram of substation integrally、correctly and automatically.

According to the present situation of measuring installation for electric energy,the main factors influencing the accurate measurements of electric energy are analyzed,which include the errors of ammeter,the errors of mutual induction device,the second loop return wiring of the mutual induction device.