A kind of control device that is used for hydroelectric vscf generator
Technical field
The utility model relates to a kind of control device of hydroelectric generator, relates in particular to a kind of control device that is used for hydroelectric vscf generator.
Background technology
At present, the generator of hydroelectric station employing both at home and abroad is conventional hydraulic generator, mainly is synchronous generator, and a small amount of common asynchronous generator is also arranged.Generator all can only move under rated speed, and generating unit speed immobilizes, and therefore, the operating condition of the hydraulic turbine only is decided by head and load, does not have the leeway of adjusting.Conventional hydraulic generator unit all is designed to when weight average head, reach optimum unit speed.When the hydraulic turbine only operates near the optimum unit speed, just has good performance and higher efficient.When head changed, the unit speed of the hydraulic turbine also can change thereupon, and the way that adopts at present is to regulate the rotating speed of the hydraulic turbine through the opening angle of regulating stator; But owing to detect the method for rotational speed of water turbine at present is fluted disc speed measuring; Reaction speed is slow, and the opening angle of regulating stator needs the regular hour, in the process of the opening angle of regulating stator; Generating unit speed can depart from optimum unit speed; And the power and the frequency of generator output change with the hydraulic turbine and rotating speed, thereby, the voltage and the non-constant of frequency stability of generator output.
Summary of the invention
The purpose of the utility model is to overcome the above-mentioned defective that prior art exists, and provides a kind of when head and load variations, can export the control device that is used for hydroelectric vscf generator of constant frequency and constant voltage.
The technical scheme of the utility model is: it comprises the hydraulic turbine, stator, generator, microcomputer governor, photoelectric encoder, controller, signal conditioning circuit; Also comprise rotor-side converter, net side converter; Transformer and drive circuit; Photoelectric encoder is an absolute optical encoder, is contained in the non-shaft stretching end of asynchronous generator, and the photoelectric encoder output is connected with the input of controller through the tach signal modulate circuit.Controller is provided with one group of output port; Wherein two output ports are connected with drive circuit II input with the input of drive circuit I respectively; The output of drive circuit I is connected with the input of rotor-side transformer; The output of drive circuit II is connected with the input of king's side converter, and another input of rotor-side converter is connected with the rotor winding of generator, and the rotor-side converter output is connected with another input of net side converter; The output of net side converter is connected with network transformer; Another output port of controller is connected with the input of microcomputer governor; Microcomputer governor is connected with guide vanes of water turbine; The hydraulic turbine carries out being connected mechanically through the shaft coupling and the rotor of generator, the network transformer that the stator winding of generator inserts and electrical network directly links to each other.
Said generator is a double-fed asynchronous generator.
Said generator is a brushless double feed generator.
The effect of the utility model is; Owing to adopt absolute optical encoder can the variation of rotational speed of water turbine be fed back to rotor-side converter and net side converter rapidly through controller; The power of the stator output of regulator generator, thus guarantee that voltage and frequency that generator sends keep constant.
Description of drawings
Fig. 1 is the utility model embodiment sketch map.
Embodiment
Below in conjunction with accompanying drawing the utility model is described further.
With reference to accompanying drawing 1, it comprises the hydraulic turbine 1, stator 11, double-fed asynchronous generator 2, microcomputer governor 9, photoelectric encoder 8, controller 7, signal conditioning circuit 10, also comprises rotor-side converter 4, net side converter 5, transformer 3 and drive circuit 6.Photoelectric encoder 8 is an absolute optical encoder, is contained in the non-shaft stretching end of asynchronous generator 2, and photoelectric encoder 8 outputs are connected through the input of tach signal modulate circuit 10 with controller 7.Controller 7 is by 80C196MC single-chip microcomputer 7-1; Voltage regulator circuit I 7-2 and voltage regulator circuit II 7-3 form; Controller 7 is provided with one group of output; Wherein two outputs are connected with drive circuit II 6-2 input with the input of drive circuit I 6-1 respectively; Drive circuit 6 is driven by pwm signal and isolation module is formed, and the output of drive circuit I 6-1 is connected with the input of rotor-side transformer 5, and the output of drive circuit II 6-2 is connected with the input of king's side converter 5; Another input of rotor-side converter 4 is connected with the rotor winding of asynchronous generator 2, and rotor-side converter 4 outputs are connected with another input of net side converter 5.The output of net side converter 5 is connected with network transformer 3; Another output of controller 7 is connected with the input of microcomputer governor 9; Microcomputer governor 9 is connected with guide vanes of water turbine 11; The hydraulic turbine 1 carries out being connected mechanically through the shaft coupling and the rotor of asynchronous generator 2, the network transformer 3 that the stator winding of double-fed asynchronous generator 2 inserts and electrical network directly links to each other.
During work; Double-fed asynchronous generator 2 is made up of two parts to the power of electrical network output; A part is the power from the stator output of double-fed asynchronous generator 2; Another part is to export through rotor-side converter 4 and net side converter 5 from the rotor of double-fed asynchronous generator 2, and the stator winding of double-fed asynchronous generator 2 links together through network transformer 3 and electrical network, and the power of the rotor winding of double-fed asynchronous generator 2 output is adjustable; The frequency of its electric current and voltage, phase place, amplitude all are adjustable; When head or changes in flow rate, photoelectric encoder 8 feeds back signal to rotor-side converter 4 and net side converter 5 through controller 7, thereby control guarantees that through rotor-side converter 4 and the current parameters of netting side converter 5 feed-in double-fed asynchronous generators 2 rotor windings voltage, the frequency of the output of double-fed asynchronous generator 2 stators are constant; The power factor (PF) of scalable electrical network absorbs the idle of grid excess simultaneously.When the hydraulic turbine 1 rotation speed change surpasses the scope that allows; Photoelectric encoder 8 feeds back to controller 7 rapidly; Control guide vanes of water turbine 11 apertures are regulated the rotating speed of the hydraulic turbine 1; Thereby let the hydraulic turbine 1 operate in the range of speeds of permission, thereby realize the rotating speed of generator output and two closed-loop controls of electric current, thereby the voltage of guaranteeing to export, frequency is constant.
It more than is a kind of execution mode of the utility model; A preferred example; For reaching the purpose of variable speed constant frequency in the hydroelectric power generation process, also can change brushless double feed generator into like double-fed asynchronous generator 2 through other mode; The rotor-side converter 4 of feed-in and net side converter 5 are introduced by rotor and are changed into by the additional winding introducing in the stator etc., and all technical schemes with the present embodiment equivalence all belong to the protection range of the utility model.