JP2005176498A - Water-power generation system using squirrel-cage induction generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-power generation system using a squirrel-cage induction generator. <P>SOLUTION: The water-power generation system is provided with a water-mill 1, a pressure sensor 2a for measuring the entrance side pressure of the water-mill 1, a pressure sensor 2b for measuring the exit side pressure, the squirrel-cage induction generator 3 driven by the water-mill 1, a rectification step-up circuit 4, a smoothing capacitor 5, a diode rectifying circuit 6, and a rotational speed controller 8 for the generator 3. An intermediate speed between a non-restraint operation speed and an operation speed suitable for power generation in a pressure value of the water-mill 1 measured by the pressure sensor 2 is calculated by using each characteristic data of a non-restraint speed and a speed suitable for power generation for each pressure of the water-mill recorded in an internal storage device of the controller 8. An operation speed command as the intermediate speed is given to the generator 3. The water-power generation system is started in a state that regenerative power generated by a difference between the intermediate operation speed and the non-restraint operation speed is smaller than when the operation speed command is given at the speed suitable for power generation. After that, it is shifted to the suitable operation speed and the regenerative power is largely outputted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vertical induction generator hydroelectric power generation system, and relates to a hydroelectric power generation facility, and more particularly to a variable speed power generation system that is effective when a change in head is large.

  In the conventional hydroelectric power generation equipment, as described in Non-Patent Document 1, a synchronous generator is generally used as the generator, and the generator is operated at a constant speed at a specified rotational speed based on the system frequency. The turbine output is controlled by adjusting the turbine flow rate with a mechanical governor. Since such a hydroelectric power generation facility has a complicated structure and becomes a large facility, the installation location is limited.

In recent years, effective utilization of natural energy has been demanded, and small hydropower generation and even smaller microhydropower generation have attracted attention. In micro hydroelectric power generation, the most important issue is to reduce the power generation cost, and a power generation facility using an induction generator while omitting a mechanical governor is common.
Japanese Patent Laid-Open No. 7-213098 Mechanical Engineering Handbook B5-45 (issued in February 1987)

  Although the micro hydroelectric power generation equipment without a flow rate adjusting mechanism is low in equipment cost, cavitation and vibration are generated when the flow rate and the head change, so that only a limited operating range can be applied. In order to solve this, a variable speed power generation system that accelerates or decelerates the rotational speed of the water turbine in response to changes in flow rate and head is required. As this method, Patent Document 1 proposes a variable speed power generation system. However, since this control method is a control method using a wound induction generator, it cannot be directly applied to a saddle induction generator that is much cheaper than a wound induction generator. That is, since the saddle type induction generator does not have a coil in the rotor, the rotor cannot be excited and power cannot be generated. In addition, when operating at an unconstrained speed, such as when the system is started up, the generated energy cannot be recovered, and when operating at the preferred power generation speed, adverse effects due to instability of the generator startup, etc. Will occur.

  The object of the present invention is to provide a hydroelectric power generation system using a vertical induction generator, which can greatly reduce the power generation cost, so that the introduction of micro hydroelectric power generation facilities is promoted and the prevention of global warming by utilizing natural energy It is useful for.

  In order to achieve the above object, a vertical induction generator variable speed hydroelectric power generation system according to the present invention includes a water turbine, a pressure sensor for measuring an inlet side pressure of the water wheel, and a pressure sensor for measuring an outlet pressure of the water wheel. A vertical induction generator driven by the water turbine, a rectifier booster circuit composed of a diode and a switching element connected to a stator winding of the vertical induction generator, and a parallel connection to the rectifier booster circuit A smoothing capacitor, a diode rectifier circuit connected in parallel with the smoothing capacitor, and a control device for the saddle-type induction generator, and recorded in an output signal of the pressure sensor and an internal storage device of the control device Based on the characteristic data of the turbine (the unconstrained speed and the preferred power generation speed range at the inlet pressure or the outlet pressure), the unconstrained speed and the preferred power generation speed of the turbine are determined. The operation speed command that gives the calculated intermediate speed is given to the vertical induction generator, and the regenerative power generated by the difference between the command operation speed and the unconstrained speed is the operation power speed command at the power generation preferred speed. The system is configured to start in a state smaller than the given case, and then shift to the preferred operating speed to output a large amount of regenerative power.

  A turbine, a pressure sensor for measuring the inlet pressure of the turbine, a pressure sensor for measuring an outlet pressure of the turbine, a saddle induction generator driven by the turbine, and the saddle induction generator A rectifier booster circuit comprising a diode and a switching element connected to the stator winding; a smoothing capacitor connected in parallel to the rectifier booster circuit; a switch circuit connected in parallel to the smoothing capacitor; A storage battery connected to a storage circuit, and a control device for the saddle-type induction generator, supplying power at the time of startup from the storage battery, and recorded in the output signal of the pressure sensor and the internal storage device of the control device An intermediate speed between the unconstrained speed of the turbine and the preferred power generation speed is calculated from the characteristic data of the turbine, and a speed command for the calculated intermediate speed is given to the saddle induction generator. The regenerative power generated by the difference between the operation speed and the unconstrained speed is started in a state smaller than the case where the operation speed command is given at the power generation preferred speed, and then the operation proceeds to the suitable operation speed to output a large amount of regenerative power The switch circuit is configured to open when the voltage of the storage battery exceeds a predetermined value.

  And the grid connection apparatus connected in parallel with the said smoothing capacitor is provided, and generated electric power is output as alternating current power.

  Furthermore, a load drive inverter connected in parallel with the smoothing capacitor is provided, and the generated power is output to the load drive inverter as DC power.

  Further, a rectifier booster circuit comprising the diode and a switching element, a smoothing capacitor connected in parallel to the rectifier booster circuit, a diode rectifier circuit connected in parallel to the smoothing capacitor, and control of the saddle type induction generator It is a vertical induction generator hydroelectric power generation system that is an inverter in which the apparatus is integrally formed.

  As described above, according to the present invention, there is provided an apparatus for calculating the unconstrained speed and the preferred power generation speed of a water turbine directly connected to a saddle type induction generator even when a saddle type induction generator having no coil is used for a rotor. Because it is equipped, the saddle type induction generator can be controlled at an operating speed smaller than the unconstrained speed, and this allows the regenerative power to be taken out as generated power from the difference between the unconstrained speed and the command operating speed. A generator hydropower generation system can be provided. In addition, it is possible to prevent an adverse effect that occurs when the system is started.

The best mode for carrying out the present invention will be described.
Embodiments of a vertical induction generator hydroelectric power generation system according to the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a first embodiment of a vertical induction generator hydroelectric power generation system according to the present invention. FIG. 2 is a block diagram of a second embodiment of the vertical induction generator hydroelectric power generation system of the present invention. FIG. 3 is a block diagram of a third embodiment of the vertical induction generator hydroelectric power generation system of the present invention. FIG. 4 is a block diagram of a fourth embodiment of the vertical induction generator hydroelectric power generation system of the present invention. FIG. 5 is a configuration diagram of a fifth embodiment of the vertical induction generator hydroelectric power generation system of the present invention.

  FIG. 1 is a first embodiment of a vertical induction generator hydroelectric power generation system according to the present invention. The water wheel 1 is connected to a pipe, and a water flow 21 having a predetermined flow rate passes through the water wheel to rotate the impeller. A pressure sensor 2 a for measuring the inlet side pressure is installed upstream of the water turbine 1. Further, a pressure sensor 2 b that measures the outlet side pressure is installed downstream of the water turbine 1. The water turbine 1 is directly connected to a saddle type induction generator 3 driven by the rotational force of the impeller to constitute a water turbine generator. A rectifying booster circuit 4 composed of a diode and a switching element is connected to the stator winding of the saddle type induction generator 3. A smoothing capacitor 5 is connected to the rectifying booster circuit 4 in parallel. Further, a diode rectifier circuit 6 is connected in parallel to the smoothing capacitor 5, and control power is supplied from the system 7 to the rectifier booster circuit 4. Furthermore, a rotation speed control device 8 that controls the rotation speed of the saddle type induction generator 3 is provided.

  When the vertical induction generator hydroelectric power generation system configured in this way is activated to start power generation, for example, the rotational speed control device 8 obtains characteristic data of the unconstrained speed and the power generation preferable speed for each pressure of the turbine. It has a recorded internal storage device, and calculates an intermediate speed between the unrestrained speed of the water turbine 1 and the preferred power generation speed from the output signals of the pressure sensors 2a and 2b and the characteristic data of the water turbine recorded in the internal storage device. Then, a command for the calculated intermediate speed (an operating speed smaller than the unconstrained speed) is given to the saddle induction generator 3 by sensorless vector control. By controlling in this way, regenerative electric power is generated by the difference between the command operation speed and the unconstrained speed, and the voltage of the smoothing capacitor 5 is boosted.

  The rotational speed control device 8 monitors the terminal voltage of the smoothing capacitor 5 and, when the terminal voltage exceeds a predetermined value, controls to increase the rotational speed of the saddle-type induction generator 3 to suppress the output. .

  According to the present embodiment, at the time of starting the system, etc., operation at an unconstrained speed (energy cannot be recovered by power generation) is not performed, and operation at a suitable power generation speed (occurrence of adverse effects due to sudden operation) Since it is not executed immediately, the influence at the time of transition can be reduced, and the generated power can be output as DC power.

  FIG. 2 shows a second embodiment of the vertical induction generator hydroelectric power generation system of the present invention. The water wheel 1 is connected to a pipe, and a water flow 21 having a predetermined flow rate passes through the water wheel 1 to rotate the impeller. A pressure sensor 2 a for measuring the inlet side pressure is installed upstream of the water turbine 1. Further, a pressure sensor 2 b that measures the outlet side pressure is installed downstream of the water turbine 1. The water turbine 1 is directly connected to a saddle type induction generator 3 driven by the rotational force of the impeller to constitute a water turbine generator. A rectifying booster circuit 4 composed of a diode and a switching element is connected to the stator winding of the saddle type induction generator 3. A smoothing capacitor 5 is connected to the rectifying booster circuit 4 in parallel. Further, a switch circuit 9 is connected to the smoothing capacitor 5. A storage battery 10 is installed in the switch circuit 9. Furthermore, a rotation speed control device 8 for controlling the rotation speed of the saddle type induction generator 3 is provided.

  In the vertical induction generator hydroelectric power generation system configured as described above, the storage battery 10 is discharged at the time of start-up, and the control power is supplied to the rectification booster circuit 4 and the rotation speed control device 8. Therefore, the vertical induction generator hydroelectric power generation system of the present embodiment can be started even in remote islands or mountainous areas where it is difficult to supply the system power supply 7.

  Since the generated power is supplied from the saddle-type induction generator 3 after the start of the power generation operation, the terminal voltage of the smoothing capacitor 5 rises and becomes higher than the terminal voltage of the storage battery 10. Therefore, the storage battery 10 is charged until the terminal voltage that has been discharged and reduced at the time of startup reaches a predetermined voltage. The switch circuit 9 opens the circuit when the voltage of the storage battery 10 exceeds a predetermined value.

  According to the second embodiment, as in the first embodiment, when the system is started, the operation at an unconstrained speed (energy cannot be recovered by power generation) is not performed, and the operation at a power generation preferable speed (rapid The occurrence of an adverse effect) is not immediately executed, so that the influence during the transition can be mitigated and the generated power can be output as DC power.

  FIG. 3 is a third embodiment of a vertical induction generator hydroelectric power generation system according to the present invention. Since the saddle type induction generator hydroelectric power generation system includes the grid interconnection device 11, it can supply the same AC power as the grid power supply 12. Other configurations are the same as those of the first embodiment, and the description thereof is omitted.

  FIG. 4 is a fourth embodiment of a vertical induction generator hydroelectric power generation system according to the present invention. Since the vertical induction generator hydroelectric power generation system includes the inverter 13, the load 14 can be directly operated. Other configurations are the same as those of the first embodiment, and the description thereof is omitted.

FIG. 5 is a fifth embodiment of a vertical induction generator hydroelectric power generation system according to the present invention.
A vertical induction generator hydroelectric power generation system includes a rectifier booster circuit composed of a diode and a switching element, a smoothing capacitor connected in parallel to the rectifier booster circuit, a diode rectifier circuit connected in parallel to the smoothing capacitor, A control device for the saddle type induction generator is integrally formed. Therefore, the size of the entire system can be reduced. Other configurations are the same as those of the first embodiment, and the description thereof is omitted.
Since the vertical induction generator hydroelectric power generation system includes the inverter 13, the load 14 can be operated directly. Other configurations are the same as those of the first embodiment, and the description thereof is omitted.

The block diagram of the 1st Example of the vertical induction generator hydroelectric power generation system of this invention. The block diagram of the 2nd Example of the vertical induction generator hydroelectric power generation system of this invention. The block diagram of the 3rd Example of the vertical induction generator hydroelectric power generation system of this invention. The block diagram of the 4th Example of the vertical induction generator hydroelectric power generation system of this invention. The block diagram of 5th Example of the vertical induction generator hydroelectric power generation system of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Waterwheel 2a, 2b Pressure sensor 3 Vertical induction generator 4 Rectification booster circuit 5 Smoothing capacitor 6 Diode rectifier circuit 7 System power supply 8 Rotational speed control device 9 Switch circuit 10 Storage battery 11 System interconnection device 12 System power supply 13 Inverter 21 Water flow

Claims (5)

  A water wheel, a pressure sensor for measuring the pressure on the inlet side of the water wheel, a pressure sensor for measuring a pressure on the outlet side of the water wheel, a vertical induction generator driven by the water wheel, and fixing of the vertical induction generator A rectifier booster circuit comprising a diode and a switching element connected to the sub winding, a smoothing capacitor connected in parallel to the rectifier booster circuit, a diode rectifier circuit connected in parallel to the smoothing capacitor, and the saddle induction The pressure of the turbine measured by the pressure sensor using the characteristic data of the unconstrained speed and the preferred power generation speed for each pressure of the turbine recorded in the internal storage device of the generator. An intermediate speed between the unconstrained operation speed and the power generation preferable operation speed is calculated, and an operation command that gives the calculated intermediate speed is given to the vertical induction generator. The regenerative power generated by the difference in the bundle operation speed is started in a state smaller than the case where the operation speed command is given at the power generation preferred speed, and then the operation proceeds to the suitable operation speed to output a large amount of regenerative power. Vertical induction generator hydroelectric power generation system.   A water wheel, a pressure sensor for measuring the pressure on the inlet side of the water wheel, a pressure sensor for measuring a pressure on the outlet side of the water wheel, a vertical induction generator driven by the water wheel, and fixing of the vertical induction generator A rectifying booster circuit comprising a diode and a switching element connected to the child winding, a smoothing capacitor connected in parallel to the rectifying booster circuit, a switch circuit connected in parallel to the smoothing capacitor, and the switch circuit A storage battery connected to the storage battery, and a control device for the saddle-type induction generator, which supplies power at the time of startup from the storage battery, and is unconstrained for each pressure of the turbine recorded in the internal storage device of the control device Using the characteristic data of the speed and the preferred power generation speed, the intermediate speed between the unconstrained speed and the preferred power generation speed in the pressure value of the turbine measured by the pressure sensor is calculated, and the calculated intermediate speed is obtained. A command is given to the vertical induction generator, and the regenerative power generated by the difference between the intermediate speed and the unconstrained speed is started in a state smaller than the case where the operation speed command is given at the power generation preferred speed, and then the preferred operation A vertical induction generator hydroelectric power generation system that shifts to speed and outputs a large amount of regenerative power and opens the switch circuit when the voltage of the storage battery exceeds a predetermined value.   The vertical induction generator hydroelectric power generation system according to claim 1, further comprising a grid interconnection device connected in parallel with the smoothing capacitor, and outputting generated power as alternating current power.   The vertical induction generator hydroelectric power generation system according to claim 1, further comprising a load drive inverter connected in parallel with the smoothing capacitor, wherein the generated electric power is output to the load drive inverter as DC power.   A rectifier booster circuit comprising the diode and a switching element; a smoothing capacitor connected in parallel to the rectifier booster circuit; a diode rectifier circuit connected in parallel to the smoothing capacitor; and a control device for the saddle induction generator. 5. The vertical induction generator hydroelectric power generation system according to claim 1, wherein the inverter is an integrated inverter.

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