PT secondary harmonic eliminating device and harmonic eliminating method

• Main Authors: YU CHUNJIANG, LI RUIGUI, ZHAO YAN, LI SHUPING, CHAI CHENCHAO, ZHANG ZHENJIANG
• Format: Patent
• Language: Chinese; English
• Published: 26.04.2017
• Subjects: BASIC ELECTRIC ELEMENTS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION; INDUCTANCES; MAGNETS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; TRANSFORMERS

The invention discloses a PT secondary harmonic eliminating device and a PT harmonic eliminating method. The PT secondary harmonic eliminating device comprises a grounding resistor R and a harmonic elimination control device, wherein one end of the grounding resistor R is connected with a common end of a PT secondary winding, and the other end of the grounding resistor R is connected with one end of a PT open-delta winding and is grounded; and the harmonic elimination control device detects voltages at both ends of the grounding resistor R, converts the voltages into an excitation current and compares the excitation current with a set value, thereby judging that ferromagnetic resonance occurs when the PT excitation current is greater than the set value, and starting a harmonic eliminating circuit. The PT secondary harmonic eliminating device judges whether the ferromagnetic resonance happens in a PT through detecting the PT excitation current, is convenient in detection and accurate in judgment, converts the