The problem of generator transformer unit protection in Hengyun C power plant

Guangdong Electric Power Hengyun, power plant generator transformer group protection asked Secretary Wei Wenwen Guangdong Thermal Power Engineering Corporation. Guangzhou 510730, Guangdong Province, adopted corresponding improvement measures during the commissioning process. 1 The external interface asked the Hengyun Power Plant 1 parent 210 river boundary unit to generate transformer group protection and adopt the factory to renovate according to the design requirements. It seems that due to the gun, there are still many questions on the external interface, such as the terminal is not connected, the cable can not be connected, and so on. After checking the manufacturer's principle, some cable wirings were redesigned, which basically solved this problem.

2 rotor point grounding and two-point grounding protection in the imitation protection of the cattle relay factory. There are two independent relays for the grounding of the rotor point and the grounding of the two points. The bridge balancing principle is adopted. Only the two-point grounding relay of the rotor is on the panel, and a balance voltage and a balance adjustment potentiometer knob are added.

The rotor voltage input signal of the two relays is only the way. By switching the splicing, it is either supplied to the rotor point grounding relay or the rotor 1 is called the grounding relay. The operation mode is è¿®1. The normal rotor voltage signal is sent. Ground the rotor to the rotor. When the rotor point is grounded, the rotor point grounding relay acts to send a signal 6. The operator of the operation hall then switches the rotor electric jade signal to the two-point grounding relay. After adjusting the balance, cast two points of grounding protection, the specific logic principle 1.

It is inconvenient to run. The rotor voltage is a strong electrical signal, and it is unsafe for the operating personnel to carry out the switching operation. After the grounding of the rotor point is signaled, if two points of grounding protection are to be cast, the rotor voltage number must first be switched to the two-point grounding relay to check the household voltage and the voltage is adjusted to make it small, and then the two points can be grounded. The exit platen of the outlet, if the operation sequence is wrong, it is possible that the bow tripping machine is the principle of the two-point grounding protection of the rotor. The insulation resistance of the ground to some point of the rotor is lower than the set value, and even metal grounding occurs. At this point, the point grounded input signal is disconnected into the two-point grounding relay, and the monitoring of the point ground signal is lost. When the point grounding is adjusted, the two-point grounding relay is adjusted to make the bridge balance. When the balanced voltage is zero, the two-point grounding is guaranteed. The grounding signal is grounded. The rotor two-point grounding circuit protection outlet tripping pressure plate. At this time, when the bridge appears again, When the balance exceeds the set voltage value, the two-point grounding protection of the rotor will trip the machine. But in fact, there are many factors that cause bridge imbalance voltage at this time. The grounding resistance may be variable and unstable when the rotor point is grounded. When the grounding resistance at the same point changes, such as when the action value changes to a metallic ground or changes from a metallic ground to a certain resistance value, it may cause The bridge protects the action in a balanced manner. But at this time, it is actually point grounded. In another case, when the rotor is grounded from point to ground, the balance of the bridge is destroyed, which will also cause the two-point grounding protection of the rotor.

For this defect in the protection principle, we have envisaged modifications on the logic loop. The rotor voltage signal is simultaneously input to the point grounding relay and the two-point grounding relay without switching; it is a normally open contact of the grounding relay in the two-point grounded outlet circuit. Under normal circumstances, the grounding is sent out, and the two-point grounding output pressure plate is withdrawn. When the rotor point is grounded, the operator records the two-point grounding relay balance voltage reading, then adjusts the finger to zero, and then puts the two-point grounding protection outlet platen. However, this method can only solve the malfunction when the rotor is changed from point ground to ungrounded, and the malfunction caused by the grounding resistance change of the point ground cannot be solved.

3 generator stator grounding protection generator generator stator grounding protection consists of two parts, is the fundamental zero-sequence voltage part, it can protect the range from the generator outlet to the neutral point of about 95; the other is the subharmonic part, it can To compensate for the lack of fundamental zero-sequence voltage, it is sensitive to the grounding reaction near the neutral point of the generator, and its protection range is set in the range of 10,15 near the neutral point. Since the fundamental zero-sequence voltage and sub-harmonic voltage are in the principle and protection range of the stator grounding protection, we propose to respectively export and transmit the fundamental zero-sequence voltage part and the sub-harmonic voltage part. This proposal is recognized by the design.

The relay circuit of the Shanghai Relay Factory is not a separate bachelor's degree, mainly engaged in electrical commissioning and installation work.

23.3 The release of power information releases power information for the whole society.

3 Conclusion The correct use of the human 刖 018 technology will greatly promote the development of an organic integrated 18 system that is naturally formed in the business systems of the power supply sector, thereby maximizing the scientific management level of the entire power supply enterprise and achieving energy efficiency and energy efficiency. The overall goal of quality of service.

Computer information system work,

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