A pumped storage unit GCB opening locking and unlocking system and method

Abstract

The invention discloses a GCB breaking locking and unlocking system and method of a pumped storage machine set. The system comprises a GCB breaking locking and unlocking judgment module, a GCB breaking loop abnormality judgment and protection module and a GCB breaking locking and unlocking execution module, wherein the GCB breaking locking and unlocking judgment module is used for judging whethera GCB breaking loop is needed to be locked or unlocked or not and sending a GCB breaking loop disconnection or closing command out, the GCB breaking loop abnormality judgment and protection module isused for comprehensively judging whether the GCB breaking locking function and the breaking function are failure not or and taking corresponding safety protection measure, and the GCB breaking lockingand unlocking execution module is used for executing GCB breaking locking and unlocking operation and feeding an on / off state back to the GCB breaking loop abnormality judgment and protection module.By the system, the functions that GCB breaking is locked at a low rotational speed of a back-to-back drag machine and the GCB breaking is unlocked when the machine set reaches a high rotational speedstate or excitation of two machine sets exits due to trip of the back-to-back drag machine can be achieved, and the necessary measure also can be timely taken to protect the safety of equipment whenthe GCB breaking locking function and the breaking function are failure.

Description

technical field [0001] The invention relates to the field of control research of a pumped storage unit, in particular to a system and method for locking and unlocking GCB gates of a pumped storage unit. Background technique [0002] There are two main ways to start the pumped storage unit under the pumping phase modulation condition, one is to use a static frequency converter to start, and the other is to use another unit as a tractor to start back to back. [0003] figure 1 Shown is a schematic diagram of the electric connection for back-to-back dragging and pumping phase modulation working conditions in the prior art. The neutral point switch 19, the excitation AC incoming switch 18, and the de-excitation switch 16 must be in the closing position, the power generation direction commutation switch 14, the drag switch 12 and GCB13 must be in the opening position, and the excitation device 17 should be set at Between the excitation AC incoming switch 18 and the de-excitatio...

AI Technical Summary

Problems solved by technology

[0008] 1. The circuit adopts a monostable relay. If the relay coil is damaged or loses power, the GCB opening and locking function will fail, and there is a risk of back-to-back unit low-speed tripping and GCB burning;

[0009] 2. The circuit simply uses the unit speed signal to block the GCB opening circuit. If there is an error in the judgment of the zero speed signal of the unit, there may be a situation where the unit starts to rotate but the speed measurement device judges that the speed is still zero. At this time, the GCB opening circuit still leads There is also the risk of GCB burning due to low-speed tripping of back-to-back units;

[0010] 3. The circuit simply uses the unit speed signal to block the GCB opening circuit, so that the unit has to wait until the speed reaches zero after the low-speed trip to restore the GCB opening function, which affects other functions such as starting the knife switch, dragging the knife switch, Opening operation of equipment such as commutation knife switch;

[0011] 4. The circuit does not distinguish between the back-to-back tractor mode and other operating modes, so that when the unit is started in any working condition, the GCB opening circuit will appear on and off, and the action frequency is too high, which may cause the GCB to open normally. The gate circuit fails, and there is a risk that the GCB cannot be disconnected when the unit is connected to the grid and the line switch is connected to the grid, which will affect the safe operation of the grid

Images