A speed regulator for a small hydropower station

Abstract

The present invention discloses a small hydropower station speed regulator, belonging to the technical field of speed regulators. The system includes an AC motor, a DC motor, an oil pump, a control system, a coupling, a fixing bracket, a measuring element, etc. The AC motor is connected to the oil pump, and the AC motor is connected to the DC motor via a detachable coupling. The present invention adds a DC motor to the existing speed regulator, and the DC motor is connected to the AC motor via a detachable coupling. Under normal circumstances, the AC motor works to complete the oil pumping task. Under special circumstances, the DC motor can be used to drive the AC motor to pump oil for the speed regulator, and provide oil pressure for starting the machine to maintain power in an emergency.

Description

Technical Field

[0001] The invention relates to the technical field of speed regulators, and in particular to a speed regulator for a small hydropower station. Background Art

[0002] After years of development, small hydropower stations are spread all over the country, providing valuable clean energy for the development of social economy. However, small hydropower stations have small investment scale and limited technical level. The AC power supply for the station is generally taken from the power station generator or the Internet line. When encountering an emergency accident in the power system, the power station is suddenly disconnected from the power system and cannot obtain AC power from the power system. The units are all shut down due to excessive speed or accidental low oil pressure, the plant power supply disappears, and various electromechanical equipment in the hydropower station will lose power and cannot operate normally. After the turbine speed governor has low accident oil pressure, the oil pump motor cannot operate without power supply or the speed governor itself has a fault that is not discovered and handled in time, and it cannot be restarted to generate electricity, which can easily cause safety accidents.

[0003] Many small hydropower stations are forced to configure emergency diesel generators, but they require very complex switching operations, which take a long time to deal with, and require high technical level and emergency handling ability of operators, which can easily cause oil fires and mechanical injury accidents. How to ensure the good operation of the speed governor, and restore the speed governor oil pump motor in an emergency, fill the speed governor oil tank, and quickly restore the operation of the turbine generator has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] The purpose of the present invention is to provide a small hydropower station speed regulator, by adding a DC motor on the basis of the existing speed regulator, the DC motor is connected to the AC motor through a detachable coupling, and the DC motor is used to drive the AC motor in special circumstances to oil the speed regulator, and to provide oil pressure for starting the machine to maintain power supply in an emergency.

[0005] In order to achieve the above object, the present invention provides a small hydropower station speed regulator, which adopts the following technical solutions:

[0006] A small hydropower station speed regulator comprises an AC motor, a DC motor, an oil pump, a control system, a coupling, a fixing frame, a measuring element, etc. The AC motor is connected to the oil pump, and the AC motor is connected to the DC motor via a detachable coupling.

[0007] Furthermore, the AC motor adopts a dual output shaft mode, the output shaft located at the AC motor is directly connected to the oil pump, and the output shaft located at the AC motor is connected to the DC motor through the detachable coupling.

[0008] Furthermore, an external fixing frame is provided on the outside of the AC motor (the AC junction box is disposed outside the fixing frame), and the DC motor is installed via the external fixing frame.

[0009] Furthermore, the external fixing frame is connected to the half-circular ring base, and the half-circular ring base is fixed to the original AC motor fixing bolt position by using extended bolts to limit the horizontal and vertical displacement of the external fixing frame. The gravity of the half-circular ring base is pressed flat on the speed regulator housing through the rubber pad.

[0010] Furthermore, the external fixing frame is connected to the half-circular ring base by bolts, with reserved bolt holes and existing pin holes. Four vertical thick steel plates are arranged in a circular ring shape of the support frame and are integrally welded to the circular ring platform above. A high-precision mounting plane is provided on the top surface and is connected to the DC motor. While ensuring the concentricity and coaxiality of the two axes, bolt holes are reserved according to the position of the DC electric fixing bolts for fixing the DC motor.

[0011] Furthermore, it also includes a DC motor control box and an oil pump control box, the oil pump control box is connected to the AC motor, the DC motor control box is connected to the DC motor, and the DC motor control box is provided with a DC motor controller to limit the starting current.

[0012] Furthermore, the DC motor control box and the oil pump control box both introduce two normally closed contacts of the control contactor as the power supply and motor start locking conditions of the DC motor control box and the oil pump control box. As long as any set of control circuit contactors is actuated, the corresponding normally closed contacts are disconnected to lock the power supply and contactor action circuit of the other set of control circuits.

[0013] Furthermore, the DC motor control box is connected to the speed regulator oil level and oil pressure measuring elements, and connected to the power station monitoring system through communication. And the oil pressure, oil pressure, and speed regulator relay displacement information are connected to create a fault diagnosis module.

[0014] The beneficial effects of the present invention are:

[0015] 1. The present invention can improve the safety of operation. In the special situation of the small power station system disconnection, all the generator sets are shut down urgently, the power supply to the factory disappears, and the governor motor cannot pump oil normally. The DC motor is used to drive the oil pump to provide oil pressure for the rapid recovery of the unit power generation operation, which greatly improves the safety performance of the power station operation. There is no need to switch the main circuit of the electrical equipment, which avoids the possibility of accidents caused by misoperation when the operator starts the diesel generator and reverses the electrical circuit.

[0016] 2. The present invention improves the efficiency of emergency response. When the factory power supply disappears in an emergency, the DC motor oil pump starts to pump oil immediately to provide pressure oil to the oil tank, saving the operator time to start the diesel generator and perform the AC power supply circuit switching operation. In addition, the speed regulator is used to quickly restore the generator operation, which not only provides a stable and reliable power supply for emergency response, but also can quickly consume the water volume of the water diversion project, speed up the decline of the super-high water level, relieve the pressure of the water diversion project in an emergency, and improve the efficiency of emergency response.

[0017] 3. The present invention has high economical practicality. Every small hydropower station has a DC power supply, so there is no need to increase large investments. This transformation method only requires a DC motor and a control box, and will not add any safety hazards to the high oil pressure equipment of the speed regulator. The transformation technology is simple, and only requires the addition of a DC motor, an external fixed bracket, a coupling, a control box, etc. The required cost is low and has strong economical efficiency. In addition, different DC motors can be selected according to the power, speed, and various sizes of the crude oil pump motor of the hydropower station, which is very easy to promote and apply in various hydropower stations. After the transformation is completed, the equipment is relatively fixed. Since there is no need for a diesel generator, the workload of routine inspection and maintenance is very small, which is very economical.

[0018] 4. Improve the operating condition of the speed governor. This generator provides the oil system fault diagnosis function. When the speed governor operating parameters change abnormally, it will issue a fault warning in advance, and prompt the staff to carry out maintenance and disposal in time before the fault occurs, which can not only avoid faults or accidents, but also effectively ensure the operating condition of the speed governor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0020] Figure 1 A structural diagram of a small hydropower station speed regulator according to an embodiment of the present invention is shown.

[0021] Figure 2 Shows Figure 1 AA profile in.

[0022] Figure 3 Shows Figure 1 BB cross-section diagram in. DETAILED DESCRIPTION

[0023] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0024] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0025] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] The specific implementation of the present invention is further described in detail below in conjunction with the drawings and examples.

[0027] The embodiment of the present invention provides a small hydropower station speed regulator, such as Figures 1 to 3 As shown, the small hydropower station speed regulator includes an AC motor 1, a DC motor 2 and an oil pump 3, wherein the AC motor 1 is connected to the oil pump 3, and the AC motor is connected to the DC motor 2 via a detachable coupling 4, and the detachable coupling 4 is used to realize the switching of the working modes of the AC motor 1 and the DC motor 2.

[0028] The present invention can transform the existing speed regulator of a small hydropower station. By using the existing speed regulator, only the three-phase asynchronous motor of the crude oil pump is transformed into a DC dual-motor drive, and a DC motor and a control box are added. A three-phase AC motor and a DC motor are connected and combined through a detachable coupling. During normal operation, the AC motor still uses the existing control box (AC contactor separation and combination) to drive the oil pump to operate, and the DC motor (rotor idling) does not do any work. In special circumstances, when the factory power supply disappears, the operator disconnects the AC motor power supply, and then manually operates the coupling to synchronize the AC motor shaft and the DC motor shaft, and then manually operates the DC motor control box to start the DC motor to rotate to pump oil for the speed regulator, and provide oil pressure for starting the machine to protect the factory power supply in an emergency. During normal operation, the DC operating box monitors the operating status of the speed regulator through the fault diagnosis module, and can diagnose the fault that is about to occur in advance.

[0029] Therefore, the present invention transforms the motor of the crude oil pump into DC. A driving motor is added to the original AC motor oil pump. Through the dual motor mode of AC motor and DC motor, the DC motor drive mode is added under the premise of the original functions of the speed regulator. The oil pump can work and pump oil under the drive of the DC motor. It can also monitor the operating parameters of the speed regulator in real time, diagnose possible faults in advance, and improve the operating conditions.

[0030] In some embodiments, the AC motor 1 adopts a dual output shaft method. The AC motor 1 is directly connected to the oil pump 3 at the bottom, and the DC motor 1 keeps the two shafts concentric at the top. The AC motor fan protection cover is removed, and the two motor shafts are connected with a detachable coupling 4.

[0031] In some embodiments, an external fixing bracket 5 is disposed on the outside of the AC motor 1 , and the DC motor 2 is mounted via the external fixing bracket 5 .

[0032] Please combine Figure 2 and Figure 3 , a fixing frame is set outside the original AC motor, and the fixing frame is connected to the half-circular ring base. The base is fixed to the original AC motor fixing bolt position by lengthened bolts to limit the horizontal and vertical displacement of the fixing frame. The gravity of the base is pressed flat on the speed regulator housing through the rubber pad. The support frame is connected by bolts, and larger bolt holes and existing sub-holes are reserved (the sub-holes are drilled and positioned after the concentricity and coaxiality of the two shafts are adjusted to meet the requirements). The support frame is arranged in a circular ring with four vertical thick steel plates and welded to the upper circular platform as a whole (the AC motor junction box is external). A high-precision mounting plane is set on the top surface to connect with the DC motor. Under the condition of ensuring the concentricity and coaxiality of the two shafts, bolt holes are reserved according to the position of the DC motor fixing bolts to fix the DC motor. The height of the fixing bracket meets the requirements of the two-axis connection and leaves a reasonable operating space. In order to take into account the convenience of operation and safe operation, the outer periphery of the coupling is completely closed, and a small door or observation ventilation hole is reserved when necessary.

[0033] In some embodiments, Figure 1 As shown, the small hydropower station speed regulator also includes a DC motor control box 6 and an oil pump control box (original equipment), the oil pump control box is connected to the AC motor, and the DC motor control box 5 is connected to the DC motor 2.

[0034] In this embodiment, an independent DC motor control box is added. The DC motor control box is separated from the crude oil pump control box, and two normally closed contacts of the control contactor are introduced into each other as the power supply and motor start-up locking conditions of the two motor control boxes. As long as any set of control circuit contactors is actuated and its normally closed contacts are disconnected, the power input and contactor action circuit of the other set of control circuits can be locked, effectively preventing the possibility of dual electric simultaneous driving of oil pumps. A DC step-down starting device is configured in the box to prevent excessive starting current from affecting the normal operation of the DC system.

[0035] In this embodiment, a startup parameter monitoring and fault diagnosis function is newly added. When the operating parameters of the speed regulator change abnormally, a fault warning is issued in advance to facilitate timely inspection and maintenance to avoid faults or accidents.

[0036] The above implementation modes are only used to illustrate the present invention, but not to limit the present invention. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention. The patent protection scope of the present invention should be defined by the claims.

Claims

1. A small hydropower station speed governor, characterized in that: It includes an AC motor, a DC motor, an oil pump, a control system, a detachable coupling, an external fixing bracket, and a measuring element. The output shaft of the AC motor is connected to the oil pump, and the AC motor is connected to the DC motor via a detachable coupling. The AC motor adopts a dual output shaft mode, the output shaft of the AC motor is directly connected to the oil pump, and the output shaft of the AC motor is connected to the DC motor through the separable coupling; An external fixing bracket is arranged outside the AC motor, and the DC motor is installed through the external fixing bracket; The measuring element provides the control system with the measured oil pressure, oil level and speed regulating relay opening in real time, and after communicating with the hydropower station monitoring system, provides the host computer with the conditions for remote monitoring of the oil pressure; It also includes a fault diagnosis module, which monitors the real-time oil pressure and oil level during the operation of the speed regulator, and automatically forms a continuous oil pressure and oil level monitoring curve in combination with the start and stop of the oil pump and the oil consumption of the speed regulator relay. Through machine deep learning, the duration, rising speed, and oil level change of normal oil pumping of each oil pump are used to judge the operating condition or fault of the oil pump; the falling speed of the static oil pressure is used to diagnose the oil leakage of each valve group of the speed regulator; the oil level of the pump start and stop is used to timely diagnose the oil leakage of the pipeline or the air leakage of the pressure oil tank capsule, provide suggestions for emergency disposal and overhaul and maintenance, and analyze the operation data information; The bottom of the external fixing frame is connected to a half-circular ring base, and the half-circular ring base is fixed to the fixing bolt position of the AC motor by using an extended bolt to limit the horizontal and vertical displacement of the external fixing frame. The gravity of the half-circular ring base is pressed flat on the speed regulator housing through a rubber pad; The external fixing frame is connected to the half-circular ring base by bolts, and four vertical thick steel plates are arranged in a circular ring shape of the support frame and are integrally welded to the circular ring platform above. A high-precision mounting plane is provided on the top surface and connected to the DC motor. Bolt holes are reserved according to the positions of the DC motor fixing bolts while ensuring the concentricity and coaxiality of the two axes, so as to fix the DC motor; It also includes a DC motor control box and an AC motor oil pump control box, wherein the AC motor oil pump control box is connected to the AC motor, and the DC motor control box is connected to the DC motor; The DC motor control box and the oil pump control box both introduce two normally closed contacts of the control contactor as the power supply and motor start locking conditions of the DC motor control box and the oil pump control box. As long as any set of control circuit contactors is actuated, the corresponding normally closed contacts are disconnected to lock the power supply input and contactor action circuit of the other set of control circuits. At the same time, a DC motor controller is configured in the DC motor control box to limit the motor starting current.

Images