A brief explanation:
1) Water cut-off protection - used in stator water cooling units and stator-rotor dual water internal cooling units Once the water cut off, the coil temperature increases. quickly, so when the cooling water pressure (or flow rate) is below a certain value, the motor switch will trip with a delay.
2) Excitation transformer overload - no different from ordinary transformer overcurrent protection, preventing the excitation transformer from overloading and overheating.
3) Excitation differential protection (main protection) - no different from ordinary transformer differential protection, it plays the role of protection against internal faults of the transformer.
4) Emergency protection of the excitation transformer ---- The so-called emergency protection refers to a protectionction other than the main protection, and the overload must be included in the emergency protection.
5) Excitation system failure - this is an abnormality in the peripheral equipment of the generator, including abnormal excitation voltage, excitation switch tripping, etc.
6) Generator Overexcitation: Mainly monitors rotor voltage. In addition to the normal "forced excitation" action, excessive rotor voltage can cause the generator stator to overvoltage.
7) Generator desynchronization —— This is a fault. The generator loses synchronization with the system, which will cause system vibration and significant voltage and current fluctuation, impacting both the generator and the system.
8) Loss of generator excitation – This is also a kind of fault. When the generator loses excitation, it will lose the electromotive force of the stator, the reactive power will flow in large quantities and it risks losing pace. .
9) Trip generator output switch coil 1 ---- The generator has several protections. Generally, one output intermediate relay is used for main protection and another output intermediate relay is used for backup protection. 1 and 2 refer to the relay coil between the two sockets.
10) Jump generator output switch coil II ---- see previous item.
11) Generator output switch does not start - the generator's normal protective action is to trip its own generator (or machine switch). When it does not trip when it should, it will pass the ").fault protection" Trip other switches on the bus to cut off the fault current.
12) Close the main steam valve - this is a protection horizontal between the electricity and the turbine. The main generator protection action indicates a generator failure. In order to quickly stop the generator, when the generator protection action takes place, a signal is sent to the engine thermal protection at the same time to close the main steam valve of the turbine.
13) Trigger the excitation switch —— This is a protective action. Generally, the generator switch does not necessarily trip when the excitation circuit fails, only the excitation switch is tripped.
14) Manual emergency stop - This is an "emergency stop button". Pressing this button is equivalent to the main protective action of the generator and is used in certain emergency situations.
15) Startup and Shutdown: It is the process of startup and shutdown.
16) Wrong power supply: i.e. equipment that should not be turned on is allit by mistake.
17) Frequency protection - rarely used, this refers to automatic load shedding (or other) devices set according to the system frequency.
18) Program reverse power ---- Refer to the following item, there is a slight difference.
19) Reverse power ---- is a kind of protection to prevent the turbine from running without steam. The active power of the generator is reversed for a certain time and the generator switch is triggered.
20) Generator differential protection - belongs to longitudinal differential protection, used to protect the internal phase short circuit fault of the generator.
21) Generator inter-turn protection - belongs to transverse difference protection, which is used to protect the inter-turn short circuit fault of the same phase coil inside the generator.
22) Emergency protectionGenerator phase-to-phase - generally refers to backup protection against phase-to-phase short-circuit faults, such as overcurrent, etc.
23) Generator overvoltage ---- used to monitor the generator stator voltage When the stator voltage exceeds approximately 1.25 times the rated voltage, the generator switch trips.
24) Stator ground zero sequence voltage - used to monitor the open delta voltage of the generator output voltage transformer. A zero sequence voltage exceeding the limit indicates that the generator has a stator ground fault.
25) Symmetrical stator overload - this is an ordinary overcurrent protection, which usually only sends a signal but does not trip.
26) Stator reverse overload - belongs to generator asymmetric fault protection, e.g. generator switcheur does not have three phases closed at the same time, etc. The asymmetry of the three-phase current of the generator will form a reverse current, which will cause abnormal vibration of the generator and other phenomena.
The above is for your reference.
I assume you are talking about thermal power plants. Then the three main hosts are turbines, boilers and generators. The impact of grid power consumption on the three main hosts is roughly described below:
When the grid load increases, the generator will increase the power generation load according to automatic instructions or manual, that is, the generator will increase the electricity production load according to automatic or manual instructions. produce more energy, the electricity network will then have a greater impact on electricity production. The resistance of the machine rotor increases and if you want to produce mores electricity, the generator must get more powerful rotating power. Then the steam turbine needs larger and higher steam parameters to improve the rotating power of the turbine rotor. Improvement in steam parameters can only be achieved through boilers. At this time, the boiler needs to increase the amount of coal entering, that is, increase the output of the coal feeder, so that the amount of coal entering the coal crusher increases and the amount of coal pulverized produced by the coal crusher increases. At this time, the current of the coal mill will increase slightly (in order to obtain an appropriate amount of oxygen, the air supply volume must be increased. In order to maintain the negative pressure balance of the furnace, the induced draft load The fan must be increased The combustion of the furnace becomes more intense and the possibility of overheating.of the heating surface of the boiler increases, leading to incomplete mechanical combustion. The loss increases while the exhaust heat loss also increases. Let's talk about other effects. Generally speaking, vibration and axial displacement of the generator rotors and turbine when the load exceeds the rated load of the unit, the feed water pump may be sealed, or the condensate water pump may be waterproof. The stress is reflected in the continuous decrease of the deaerator water level or the increase of the condenser water level; the previous output stress is reflected in the water level of the long boiler drum. Time is running out. (Supercritical units do not have steam drums).
My hands are tired from typing. It's a big problem. If you explain it in detail, you can print a few sheets of A4 paper. I won't say more.