Electrical system of power station and power station

Abstract

The utility model discloses an electrical system of a power station and the power station, and relates to the field of power generation systems, the system comprises a generator, a grid-connected point switch, at least one high-voltage side load device and a processing unit, the power output end of the generator is connected with a high-voltage bus of the power station; the first end of the grid-connected point switch is used for being connected to an external power grid system, the second end of the grid-connected point switch is connected with the high-voltage bus, the power access end of each high-voltage side load device is connected with the high-voltage bus, and each high-voltage side load device obtains a working power supply at the high-voltage bus; the processing unit is connected with the generator, the grid-connected point switch and the controlled end of each high-voltage side load device so as to control the rotating speed of a generator rotor of the generator, enable the grid-connected point switch to be in an on or off state and control the device operation load of the high-voltage side load device. According to the technical scheme disclosed by the utility model, the power station can enter an isolated island operation state, and the operation stability of the power station is improved.

Description

Technical Field

[0001] The utility model relates to the field of power generation systems, in particular to an electrical system of a power station and a power station. Background Art

[0002] In order to further promote the classification of domestic waste, the whole society is accelerating the construction of a system for the classified placement, collection, transportation and treatment of domestic waste. Among them, by comprehensively considering factors such as regional characteristics, population, economic development level and the principle of burning when appropriate, the construction of domestic waste incineration power plants is gradually and orderly advancing. At present, various places are carrying out the construction of domestic waste incineration treatment facilities on a large scale, among which a large number of domestic waste incineration treatment facilities are small domestic waste incineration treatment facilities, including small domestic waste incineration power plants.

[0003] However, most small-scale domestic waste incineration power stations are small-scale domestic waste incineration power stations with a capacity of less than 200t. The installed capacity of such power stations is about 3~5MW, and the voltage level of grid-connected power generation is generally around 10kV. However, the stability of the power grid at this voltage level is poor compared to the stability of the high-voltage power grid. During operation, small-scale domestic waste incineration power stations often need to enter the island operation state from the normal state due to the poor stability of the external power grid system. Among them, the island operation of the power station means that when the external power grid system fails, the generators of the power station can still form an independent small power grid within a limited range to ensure that strategic facilities can continue to supply power and reduce the impact of accidents on business operations. Therefore, the island operation of power stations is of great significance.

[0004] However, the electrical main connections of current small-scale municipal solid waste incineration power plants cannot realize the isolated operation of the power plants. When the power plant encounters an abnormality in the external power grid system, the main equipment such as the generator of the power station will be greatly impacted by the drastic load changes, which is prone to equipment failure, resulting in poor operating stability of the power station. Utility Model Content

[0005] In view of this, the utility model provides an electrical system of a power station and a power station, the main purpose of which is to solve the technical problem that the existing power station cannot enter the island operation state from the normal operation state, resulting in poor operation stability of the power station.

[0006] To achieve the above object, the utility model provides an electrical system of a power station, the system comprising:

[0007] A generator, wherein the power output end of the generator is connected to the high-voltage bus of the power station;

[0008] A grid connection point switch, wherein a first end of the grid connection point switch is used to be connected to an external power grid system, and a second end of the grid connection point switch is connected to the high-voltage busbar, and is used to make the circuit connection between the high-voltage busbar and the external power grid system in an on state or an off state;

[0009] At least one high-voltage side load device, wherein the power access terminal of each of the high-voltage side load devices is connected to the high-voltage bus, and each of the high-voltage side load devices obtains working power from the high-voltage bus;

[0010] A processing unit, wherein the first interactive end of the processing unit is connected to the controlled end of the generator, and is used to control the rotation speed of the generator rotor of the generator; the second interactive end of the processing unit is connected to the controlled end of the grid-connected point switch, and is used to put the grid-connected point switch in an on or off state; the third interactive end of the processing unit is connected to the controlled end of each of the high-voltage side load devices, and is used to control the equipment operating load of the high-voltage side load devices.

[0011] In one embodiment of the utility model, optionally, the system further includes: a plant transformer, wherein the high-voltage end of the plant transformer is connected to the high-voltage bus, and the low-voltage end of the plant transformer is connected to the low-voltage bus of the power station, for converting the high-voltage electricity of the high-voltage bus into low-voltage electricity and providing low-voltage electricity to the low-voltage bus; at least one low-voltage side load device, wherein the power access end of each of the low-voltage side load devices is connected to the low-voltage bus, and obtains working power at the low-voltage bus; the fourth interactive end of the processing unit is connected to the controlled end of each of the low-voltage side load devices, for controlling the equipment operating load of the low-voltage side load device.

[0012] In one embodiment of the utility model, optionally, the system also includes: a standby transformer, wherein the high-voltage end of the standby transformer is connected to the high-voltage bus, and the low-voltage end of the standby transformer is connected to the low-voltage bus of the power station, for converting the high-voltage electricity of the high-voltage bus into low-voltage electricity and providing low-voltage electricity to the low-voltage bus.

[0013] In one embodiment of the utility model, optionally, the system also includes a voltage sensor, which is arranged at the external power grid system and is used to obtain the voltage value of the external power grid system. The output end of the voltage sensor is connected to the fifth interaction end of the processing unit and is used to send the voltage value to the processing unit.

[0014] In one embodiment of the utility model, optionally, the generator is provided with a condenser; the sixth interactive end of the processing unit is connected to the controlled end of the condenser, and is used to control the vacuum degree of the turbine exhaust port of the generator through the condenser.

[0015] In one embodiment of the present invention, optionally, the system further comprises: a system alarm unit, and a controlled end of the system alarm unit is connected to the seventh interactive end of the processing unit.

[0016] In one embodiment of the present invention, optionally, the system alarm unit is a reminder light and / or a buzzer.

[0017] In one embodiment of the present invention, optionally, the processing unit has a remote communication port for connecting to a remote host computer.

[0018] In one embodiment of the utility model, optionally, the system further includes: a generator grid-connected switch, wherein a first end of the generator grid-connected switch is connected to the high-voltage bus, and a second end of the generator grid-connected switch is connected to a power output end of the generator, for making the circuit connection between the generator and the high-voltage bus in an on state or an off state; an eighth interactive end of the processing unit is connected to a controlled end of the generator grid-connected switch, for making the generator grid-connected switch in an on state or an off state.

[0019] In addition, to achieve the above-mentioned purpose, the utility model also proposes a power station, including the electrical system of the power station as mentioned above.

[0020] The utility model provides an electrical system of a power station and a power station, wherein the generator of the electrical system of the power station transmits the generated electric energy to the high-voltage bus, the high-voltage bus supplies power to the high-voltage side load equipment, and transmits the electric energy to the external power grid system through the grid connection point switch. When an abnormality occurs in the external power grid system and the power station needs to enter an island operation state, the processing unit can increase the load of the high-voltage side load equipment to reduce the load of the connecting line of the power station to zero, and further, the speed of the generator rotor of the generator is in a relatively stable speed range to protect the generator, and the grid connection point switch is disconnected to disconnect the power station from the transmission line of the external power grid system, so that the power station can enter an island operation state, thereby improving the operation stability of the power station.

[0021] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0023] Figure 1 One of the structural schematic diagrams of an electrical system of a power station provided by an embodiment of the utility model is shown;

[0024] Figure 2 A second structural schematic diagram of an electrical system of a power station provided by an embodiment of the utility model is shown;

[0025] Figure 3 A third structural schematic diagram of an electrical system of a power station provided by an embodiment of the utility model is shown;

[0026] Figure 4 A fourth structural schematic diagram of an electrical system of a power station provided by an embodiment of the utility model is shown. DETAILED DESCRIPTION

[0027] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0028] In order to further explain the technical means and effects adopted by the utility model to achieve the predetermined utility model purpose, the specific implementation methods, structures, features and effects of the utility model application are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

[0029] Combine the following Figures 1 to 4 An electrical system of a power plant and a power plant according to some embodiments of the present invention are described.

[0030] like Figure 1 As shown, an electrical system 100 of a power station is provided in one embodiment of the present invention.

[0031] In the above embodiment, the electrical system 100 of the power station includes a generator 110 , a grid connection point switch 120 , a processing unit 140 and at least one high-voltage side load device 130 .

[0032] The generator 110 may be a power generation device of a small-scale domestic waste incineration power station, such as a generator set, which may be a steam turbine generator with components such as a generator excitation regulator, a steam turbine bypass condensation system, and a condenser. Furthermore, the high-voltage side load device 130 may be a high-voltage electrical device such as an induced draft fan, and the unit starting power supply of the generator 110 is conducted by a 10KV high-voltage bus 150.

[0033] Specifically, the power output end of the generator 110 is connected to the high-voltage bus 150 of the power station to transmit the generated power to the high-voltage bus 150; wherein, the voltage of the high-voltage bus 150 can be 10KV to supply power to each high-voltage side load device 130. Here, the high-voltage bus 150 can be a bus with a high voltage level of 10KV or the like that the power station has, and the specific voltage level can be determined according to the actual situation. Furthermore, the first end of the grid connection point switch 120 is used to connect to the external power grid system 200, and the second end of the grid connection point switch 120 is connected to the high-voltage bus 150, which is used to make the circuit connection between the high-voltage bus 150 and the external power grid system 200 in a conducting state or a disconnected state, thereby realizing the connection and disconnection of the small-scale domestic waste incineration power station with the external power grid system 200. The grid-connection point switch 120 is connected in series between the external power grid system 200 and the high-voltage bus 150 to adjust the on / off state of the circuit between the external power grid system 200 and the high-voltage bus 150 .

[0034] Furthermore, the power access terminal of each of the high-voltage side load devices 130 is connected to the high-voltage bus 150, and each of the high-voltage side load devices 130 obtains working power at the high-voltage bus 150. A 10kV distribution cabinet can be set between each of the high-voltage side load devices 130 and the high-voltage bus 150, and the high-voltage electricity of the high-voltage bus 150 is introduced into the high-voltage side load device 130 through the 10kV distribution cabinet. At the same time, an emergency stop control button can be set near the high-voltage side load device 130 to control the high-voltage side load device 130.

[0035] Further, the first interactive end of the processing unit 140 is connected to the controlled end of the generator 110, and is used to control the speed of the generator rotor of the generator 110. The second interactive end of the processing unit 140 is connected to the controlled end of the grid-connected point switch 120, and is used to make the grid-connected point switch 120 in an on or off state. The third interactive end of the processing unit 140 is connected to the controlled end of each of the high-voltage side load devices 130, and is used to control the equipment operation load of the high-voltage side load device 130. Specifically, the processing unit 140 can be a computer device such as a control terminal and a controller. A distributed control system (DCS) can be set in the processing unit 140 to control the generator 110, the grid-connected point switch 120, and the high-voltage side load device 130. Here, the processing unit 140 controls the equipment operation load of the high-voltage side load device 130, makes the grid-connected point switch 120 in an on or off state, and controls the speed of the generator rotor of the generator 110. The method can be implemented based on the program of the prior art set in the processing unit 140.

[0036] Here, the process of enabling a small-scale domestic waste incineration power station to realize island operation by the technical solution of this embodiment is explained: First, when the small-scale domestic waste incineration power station needs to enter the island operation mode, the processing unit can increase the equipment operation load of each high-voltage side load device to reduce the generator load, adjust it to the load of the island operation, and reduce the tie line load to near 0; further, the processing unit enables the electro-hydraulic regulation system of the generator to stabilize the speed of the generator rotor within a preset speed range, such as 3000 rpm; further, when the speed of the generator rotor is stable, the grid connection point switch can be disconnected to enable the small-scale domestic waste incineration power station to enter the island operation mode. Further, when the external power grid system suddenly becomes abnormal, it is necessary to make the small-scale domestic waste incineration power station enter the island operation mode unpredictably; after the grid connection point switch is suddenly disconnected, the generator electro-hydraulic regulation system automatically switches to the speed control mode, at which time the generator rotor speed may increase a lot, which is likely to cause the OPC valve to operate, and the processing unit can control the speed of the generator to achieve the island operation mode.

[0037] The electrical system of the power station proposed in the embodiment of the utility model, the generator of the electrical system of the power station transmits the generated electric energy to the high-voltage bus, the high-voltage bus supplies power to the high-voltage side load equipment, and transmits the electric energy to the external power grid system through the grid connection point switch. When an abnormality occurs in the external power grid system and the power station needs to enter the island operation state, the processing unit can increase the load of the high-voltage side load equipment to reduce the load of the connecting line of the power station to zero, and further, the speed of the generator rotor of the generator is in a relatively stable speed range to protect the generator, and the grid connection point switch is disconnected to disconnect the power station from the transmission line of the external power grid system, so that the power station can enter the island operation state, thereby improving the operation stability of the power station.

[0038] In one embodiment of the present invention, optionally, Figure 2 As shown, the system further includes a plant transformer 160 and at least one low-voltage side load device 170 .

[0039] Among them, the high-voltage end of the plant transformer 160 is connected to the high-voltage bus 150, and the low-voltage end of the plant transformer 160 is connected to the low-voltage bus 180 of the power station, which is used to convert the high-voltage electricity of the high-voltage bus 150 into low-voltage electricity and provide low-voltage electricity to the low-voltage bus 180. Here, the low-voltage bus 180 can be a bus with a low voltage level of 400V or the like that is provided by the power station. Further, the power access end of each of the low-voltage side load devices 170 is connected to the low-voltage bus 180, and the working power supply is obtained at the low-voltage bus 180. Here, the low-voltage side load device 170 can be a low-voltage power-consuming device in the power station, and its power consumption is conducted from the plant transformer 160 to the low-voltage bus 180, and a separate power supply is no longer provided. Further, the low-voltage plant motors in the low-voltage side load devices 170 are generally Class I motors and Class II and III motors of 75kW and above are directly distributed by the low-voltage distribution cabinet. Furthermore, an emergency stop control button is provided near each low-voltage side load device 170 for controlling the low-voltage side load device 170. Furthermore, the fourth interactive end of the processing unit 140 is connected to the controlled end of each low-voltage side load device 170 for controlling the equipment operation load of the low-voltage side load device 170.

[0040] In the above embodiment, the high voltage electricity of the high voltage bus can be converted into low voltage electricity through the plant transformer, and the low voltage side load equipment can be powered by the low voltage bus; further, since the power load is mainly concentrated in the main factory building, the plant power distribution can mainly adopt a radial distribution method; further, when it is necessary to make the small-scale domestic waste incineration power station enter the island operation mode, the low-voltage side load equipment and the high-voltage side load equipment can be controlled at the same time to increase the operating load, reduce the load of the generator set to adjust to the load of the island operation, so that the small-scale domestic waste incineration power station can quickly enter the island operation mode to protect the main equipment.

[0041] In one embodiment of the present invention, optionally, Figure 3 As shown, the system preferably includes a standby transformer 190. Specifically, the high-voltage end of the standby transformer 190 is connected to the high-voltage bus 150, and the low-voltage end of the standby transformer 190 is connected to the low-voltage bus 180 of the power station, for converting the high-voltage electricity of the high-voltage bus 150 into low-voltage electricity, and providing low-voltage electricity to the low-voltage bus 180. Among them, the low-voltage bus 180 of the low-voltage section of the plant power supply can also be wired in a single-bus segmented manner, which is not limited here. In the above embodiment, the plant transformer and the standby transformer can serve as hidden standby for each other to supply power to the plant load, thereby improving the stability of the power supply to the plant load.

[0042] In one embodiment of the present invention, optionally, Figure 4As shown, the system also includes a voltage sensor S. The voltage sensor S is arranged at the external power grid system 200, and is used to obtain the voltage value of the external power grid system 200. The output end of the voltage sensor S is connected to the fifth interactive end of the processing unit 140, and is used to send the voltage value to the processing unit 140. Among them, the voltage sensor S is connected in series between the external power grid system 200 and the grid connection point switch 120, and is used to obtain the voltage of the external power grid system 200, so that the processing unit 140 determines whether to make the power station enter the island operation state based on the voltage of the external power grid system 200. Here, the processing unit 140 determines whether to make the power station enter the island operation state based on the voltage of the external power grid system 200. The method can be implemented based on the program in the prior art. In the above embodiment, when an abnormality occurs in the external power grid system, the voltage abnormality of the external power grid system can be quickly identified by the voltage sensor, so that the small-scale domestic waste incineration power station can quickly enter the island operation mode.

[0043] In one embodiment of the utility model, the generator is optionally provided with a condenser, which acts as a cold source in the thermal cycle of the steam turbine device of the generator, reduces the exhaust temperature and exhaust pressure of the steam turbine, and can improve the thermal cycle efficiency; the main function of the condenser is to establish and maintain a high vacuum at the exhaust port of the steam turbine. The sixth interactive end of the processing unit is connected to the controlled end of the condenser, and is used to control the vacuum degree of the steam turbine exhaust port of the generator through the condenser. Further, when it is necessary to enter the island operation mode, the turbine bypass condensation system can be put into use, so that when the operating conditions of the boiler and the steam turbine do not match, that is, when the amount of steam generated by the boiler is greater than the amount of steam required by the steam turbine, the excess steam can be directly introduced into the condenser after bypass temperature reduction and pressure reduction without entering the steam turbine, and the excess gas is discharged. At the same time, it should be noted that the load of the waste heat incineration furnace should not be too low to ensure the operating temperature. In the above embodiment, when the small-scale domestic waste incineration power station needs to enter the island operation mode, the vacuum degree of the condenser is controlled by the processing unit to avoid excessive temperature of the rear cylinder of the turbine, thereby ensuring stable operation of the generator.

[0044] In one embodiment of the utility model, optionally, the system further comprises a system alarm unit, and the controlled end of the system alarm unit is connected to the seventh interactive end of the processing unit. The system alarm unit can be a reminder light and / or a buzzer, which can be set in the monitoring room of the power station to issue an alarm prompt message when an unpredictable island operation mode occurs. In the above embodiment, the processing unit can determine whether it is necessary to put the power station into the island operation mode based on the voltage of the external power grid system. When an abnormality occurs in the external power grid system and the power station needs to enter the island operation mode, an alarm prompt message can be issued by the system alarm unit to enable relevant staff to monitor the operation of the power station at the first time.

[0045] In one embodiment of the utility model, the processing unit may optionally have a remote communication port for connecting to a remote host computer. Here, the host computer may be a remote control terminal such as a controller or a server for remotely controlling the power station, and is used to perform data interaction with the processing unit, modify the functional configuration of the processing unit, and other operations. In the above embodiment, the processing unit may be remotely operated based on the remote communication port, thereby improving the control capability of the system.

[0046] In one embodiment of the present invention, optionally, Figure 4 As shown, the system also includes a generator grid-connected switch 121. Specifically, the first end of the generator grid-connected switch 121 is connected to the high-voltage bus 150, and the second end of the generator grid-connected switch 121 is connected to the power output end of the generator 110, which is used to make the circuit connection between the generator 110 and the high-voltage bus 150 in an on state or an off state. Further, the eighth interactive end of the processing unit 140 is connected to the controlled end of the generator grid-connected switch 121, which is used to make the generator grid-connected switch 121 in an on or off state. Specifically, when the power station is not successfully isolated, the processing unit 140 can trip the generator grid-connected switch 121, and the 10kV plant power of the high-voltage bus 150 will be completely lost. Furthermore, the safety section can be automatically started to ensure the continuous power supply of the main equipment such as the water supply pump, auxiliary lubricating oil pump, cranking, air compressor, DCS, etc. of the power station, and the generator unit can be safely shut down in an emergency. If the automatic cranking fails after the steam turbine speed reaches 0, personnel should be immediately organized to manually crank the turbine to prevent the accident from expanding. In the above embodiment, when the power station cannot enter the island operation mode, the generator can be disconnected from the high-voltage bus to ensure that the various equipment of the power station is not impacted to the greatest extent.

[0047] It is understandable that the composition of the electrical system of the power station, the selection of each component in the electrical system of the power station, and the signal type of the interactive signal in the electrical system of the power station can be selected and set according to the actual scenario of the production design, and this embodiment does not make specific restrictions. In addition, the control method set in the processing unit can also be implemented by a program module in the prior art, and this embodiment does not make specific restrictions either.

[0048] On the other hand, an embodiment of the present invention provides a power station, characterized by comprising the electrical system of the power station as described above.

[0049] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. An electrical system of a power station, characterized in that: The system comprises: A generator, wherein the power output end of the generator is connected to the high-voltage bus of the power station; A grid connection point switch, wherein a first end of the grid connection point switch is used to be connected to an external power grid system, and a second end of the grid connection point switch is connected to the high-voltage busbar, and is used to make the circuit connection between the high-voltage busbar and the external power grid system in an on state or an off state; At least one high-voltage side load device, wherein the power access terminal of each of the high-voltage side load devices is connected to the high-voltage bus, and each of the high-voltage side load devices obtains working power from the high-voltage bus; A processing unit, wherein the first interactive end of the processing unit is connected to the controlled end of the generator, and is used to control the rotation speed of the generator rotor of the generator; the second interactive end of the processing unit is connected to the controlled end of the grid-connected point switch, and is used to put the grid-connected point switch in an on or off state; the third interactive end of the processing unit is connected to the controlled end of each of the high-voltage side load devices, and is used to control the equipment operating load of the high-voltage side load devices.

2. The system according to claim 1, characterized in that The system further comprises: A plant transformer, the high-voltage end of the plant transformer is connected to the high-voltage bus, and the low-voltage end of the plant transformer is connected to the low-voltage bus of the power station, for converting the high-voltage electricity of the high-voltage bus into low-voltage electricity and providing low-voltage electricity to the low-voltage bus; At least one low-voltage side load device, each of which has a power access terminal connected to the low-voltage bus to obtain a working power supply from the low-voltage bus; The fourth interactive end of the processing unit is connected to the controlled end of each of the low-voltage side load devices, and is used to control the device operating load of the low-voltage side load device.

3. The system according to claim 2, characterized in that The system further comprises: A standby transformer, wherein the high-voltage end of the standby transformer is connected to the high-voltage bus, and the low-voltage end of the standby transformer is connected to the low-voltage bus of the power station, and is used to convert the high-voltage electricity of the high-voltage bus into low-voltage electricity and provide low-voltage electricity to the low-voltage bus.

4. The system according to any one of claims 1 to 3, characterized in that: The system further comprises: A voltage sensor is provided at the external power grid system and is used to obtain the voltage value of the external power grid system. The output end of the voltage sensor is connected to the fifth interaction end of the processing unit and is used to send the voltage value to the processing unit.

5. The system according to claim 4, characterized in that The generator is provided with a condenser; the sixth interactive end of the processing unit is connected to the controlled end of the condenser, and is used to control the vacuum degree of the turbine exhaust port of the generator through the condenser.

6. The system according to claim 5, characterized in that The system further comprises: A system alarm unit, wherein the controlled end of the system alarm unit is connected to the seventh interactive end of the processing unit.

7. The system according to claim 6, characterized in that The system alarm unit is a reminder light and / or a buzzer.

8. The system according to claim 5, characterized in that The processing unit has a remote communication port for connecting to a remote host computer.

9. The system according to claim 5, characterized in that The system further comprises: A generator grid-connected switch, wherein a first end of the generator grid-connected switch is connected to the high-voltage bus, and a second end of the generator grid-connected switch is connected to the power output end of the generator, and is used to make the circuit connection between the generator and the high-voltage bus in a conducting state or a disconnected state; The eighth interactive end of the processing unit is connected to the controlled end of the generator grid-connected switch, and is used to make the generator grid-connected switch be in an on or off state.

10. A power station, characterized in that: An electrical system comprising a power plant as claimed in any one of claims 1 to 9.

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