JP2013066319A - Wind generator system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wind generator system, controlling generated power of a generator with a power converter, capable of preventing excessive rotation of a blade and failure of the power converter by variably controlling a pitch angle of the blade, thus controlling input energy from the blade corresponding to transmittable power of the power converter, when the transmittable power is restricted due to degradation in cooling performance for cooling the power converter.SOLUTION: The wind generator system comprises: cooling performance detection means for detecting cooling performance of a cooling system or a cooling state of a power converter including a converter and an inverter; and pitch angle command value correction means for correcting a pitch angle command value calculated by a pitch angle command value calculation means. On the basis of a detection result of the cooling performance detection means, the pitch angle command value correction means corrects the pitch angle command value and performs a command of variably controlling a pitch angle of the blade.

Description

  The present invention relates to a wind power generation system that is connected to a power system, generates electric power from input energy by wind power using a generator, converts the generated power into desired power using a power converter, and transmits the power to the power system. It is about the system.

  In recent years, in order to improve the power generation efficiency of wind power generation systems, variable speed wind power generation systems that operate power generators at variable speeds using power converters such as inverters and converters have become mainstream.

  The energy transmission unit of the variable-speed wind turbine system is mechanically connected to a blade that converts wind energy into rotational energy, a shaft that transmits rotational energy obtained by the blade to a gear that is a speed increaser, and the shaft A gear, a generator mechanically connected to the gear for converting rotational energy into electric power, a power converter for converting the output frequency of the generator into a frequency of an interconnected power system, and conversion into a commercial frequency by the power converter And a transformer that boosts the AC power generated and transmits the AC power to the power system.

  When the wind power generation system receives input energy corresponding to the rating of the wind power generation system from the wind, and the power transmitted from the power converter to the power grid connected to the power converter is limited by some factor, the input energy There is a difference between the energy of a certain wind and the electrical energy output to the power system, and this energy difference may increase the rotation speed of the blade and cause over-rotation.

  The power transmitted to the grid by the power converter is the product of the grid voltage at the interconnection point and the current flowing through the grid. When a system fault such as a ground fault occurs, the system voltage becomes lower than the rated value. Since a power converter usually cannot continuously flow a current equal to or higher than the rated current, the power that can be transmitted by the power converter is limited to a rated value or less during the system fault continuation period. Therefore, if a system fault occurs in a state where the wind power generation system is generating power in the vicinity of the rating, the blade may be over-rotated.

  In Patent Document 1, when an accident in the power system is detected, the wind turbine pitch angle is set to the feather state to reduce the input energy of the wind, and the crowbar circuit is inserted to prevent the overcurrent from flowing into the power converter. A method is disclosed.

  Further, in Patent Document 2, by appropriately controlling the pitch angle during the power system accident, the blade rotation speed during the system accident is maintained within the operable range of the wind power generation system, and the system accident is canceled. A technique for restarting power generation as soon as it is detected is disclosed.

WO2004 / 0697958 Japanese Patent No. 4501958

  The above known technique is a solution to an event in which the rated power of the wind power generation system cannot be received due to factors on the grid side. On the other hand, there is an event in which the rated power of the wind power generation system cannot be sent to the system due to the factor of the power converter itself, not the factor on the grid side.

  Specifically, a trip due to an increase in ambient temperature of the power converter can be considered. If the ambient temperature of the power converter becomes higher than the operating temperature range of the power converter, sufficient cooling capacity of the power converter cannot be obtained, and the components inside the power converter (semiconductor switching elements and reactors) Etc.), the temperature may become higher than the design value, resulting in failure.

  In order to avoid failure of the power converter, there is a power converter protection method that detects the temperature of a component inside the power converter and stops the power converter when an abnormal rise in the temperature of the component is detected. The converter will not stop generating electricity.

  When the power converter trips or stops power generation due to a temperature abnormality of the power converter, the input energy of the wind power generation system is stored as rotational energy of a rotating body such as a blade, and the rotational speed increases. There is a risk of rotation.

  The increase in ambient temperature of the power converter is different from the system factor, and a new countermeasure mechanism is required to avoid blade over-rotation.

  An object of the present invention is to control input energy from a blade according to the transmittable power when the transmittable power of the power converter is limited due to a decrease in cooling capacity for cooling the power converter, and the blade A wind power generation system that prevents over-rotation of the engine and failure of the power converter is provided.

  As means for solving the problems of the present invention, a converter for converting variable frequency generated power output from a synchronous generator mechanically connected to a variable pitch angle blade to DC power, and output from the converter A smoothing capacitor that smoothes the DC power; and an inverter that is electrically connected to the power system, converts the DC power from the converter to the fixed frequency AC power through the smoothing capacitor, and outputs the AC power to the power system; A pitch angle command value calculating means for calculating a pitch angle command value for performing variable control of the pitch angle of the blade, and a command for mechanically adjusting the pitch angle from the pitch angle command value; the converter; and A wind power generation system having a cooling system for cooling the inverter, the cooling capacity of the cooling system, or the controller And a cooling capacity detecting means for detecting a cooling state of a power converter including the inverter and the inverter, and a pitch angle command value correcting means for correcting the pitch angle command value calculated by the pitch angle command value calculating means. The pitch angle command value correcting means corrects the pitch angle command value based on the detection result of the cooling capacity detecting means, and variably controls the pitch angle of the blade according to the corrected pitch angle command value. It is characterized by issuing a command to perform.

  By variably controlling the pitch angle of the blade, the input energy from the blade can be controlled according to the power that can be transmitted by the power converter while the operation of the power conversion system is continued, and the blade can be over-rotated. In addition to preventing the failure of the power converter.

BRIEF DESCRIPTION OF THE DRAWINGS The whole structure explanatory drawing of the wind power generation system of 1st Example of this invention. Control system explanatory drawing of the wind power generation system of 1st Example of this invention. The power converter controller explanatory drawing of 1st Example of this invention. The cooling capacity detection table of the cooling capacity detector 3000 of the first embodiment of the present invention. Explanatory drawing of the high-order controller 1000 and the pitch angle corrector 6000 calculation block of 1st Example of this invention. Other embodiment explanatory drawing of this invention 1 Example. Other embodiment explanatory drawing of this invention 1 Example. Other embodiment explanatory drawing of this invention 1 Example. Other embodiment explanatory drawing of this invention 1 Example. Explanatory drawing of the operation | movement waveform of 1st Example of this invention. The power converter and cooling system explanatory drawing of the wind power generation system of 2nd Example of this invention. Control system explanatory drawing of the wind power generation system of 2nd Example of this invention. Control system explanatory drawing of the wind power generation system of 3rd Example of this invention. Control system explanatory drawing of the wind power generation system of 4th Example of this invention. Control system explanatory drawing of the wind power generation system of 5th Example of this invention. Explanatory drawing about the state before and behind variably controlling the pitch angle of the braid | blade 10 in this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings for explaining the embodiments, elements having the same function are given the same reference numerals. Moreover, parallel switching elements 21m to 21r and 22m to 22r, which are installed in the same cooling fin and are connected in reverse parallel to the IGBT, as shown in FIG. 13 or the like, are replaced with semiconductor switching elements 21m to 21r and 22m. Will be referred to as ~ 22r.

  A present Example demonstrates the example of the wind power generation system 1 in case a power converter is cooled with cooling water.

  A wind power generation system 1 according to the present embodiment converts wind energy into electric power by a generator having blades and permanent magnets, converts the electric power to a commercial frequency by a power converter, and transmits the electric power to an electric power system. It is.

  In FIG. 1, the structural example of the wind power generation system 1 of a present Example is shown.

  The wind power generation system 1 includes a blade 10 that converts wind energy into rotational energy, a hub 11 that supports the blade and transmits the rotational force of the blade to the shaft, a shaft 13 that transmits the rotational force to the gear 14, and the gear mechanically. A generator 15 that is connected to convert rotational energy into electric energy, a power converter 20 that converts AC power output from the generator 15 into power having a frequency of a power system linked thereto, and an AC output of the power converter 20 It is composed of a transformer 30 that boosts electric power and sends it to the system.

  The generator 15 and the power converter 20 are connected via a power cable 25, and the power converter 20 and the transformer 30 are connected via a power cable 26. The shaft 13, the gear 14, and the generator 15 are installed in the nacelle 60, and the power converter 20 is installed in the tower 70.

  An anemometer 201 is installed in the upper part of the nacelle 60, and the output of the anemometer 201 is input to a host controller 1000 described later. The power converter 20 is a water-cooled power converter that is cooled by cooling water, and is connected to a cooling system 3 that cools the cooling water via a cooling water pipe.

  The operation of the wind power generation system 1 will be described.

  The wind power generation system 1 obtains rotational energy when the blade 10 receives wind, and rotates the rotor of the generator 15 via the shaft 13 and the gear 14 by the rotational energy.

  The rotor of the generator 15 is provided with a permanent magnet. When the rotor rotates, the magnetic flux linked to the stator winding changes, and an AC induced power is generated in the stator winding. .

  The power converter 20 has a frequency equal to the frequency of the induced voltage in the stator winding of the generator 15, and outputs an alternating voltage whose phase is delayed with respect to the induced voltage, thereby generating effective power from the generator 15. Receive. The power converter 20 converts the active power obtained from the generator 15 into a frequency equal to that of the power system 2 and transmits the power to the power system 2.

  The input torque from the wind is adjusted by adjusting the pitch angle of the blade 10, and the pitch angle is adjusted by the host controller 1000 described later so that the rotation speed of the blade becomes a rotation speed command value corresponding to the wind speed.

  Details of the control system of the wind power generation system 1 and the power converter 20 will be described with reference to FIG.

  The wind power generation system 1 roughly includes two controllers. One is a host controller 1000 that calculates the pitch angle command value φref and the system transmission power command value Pref of the power converter 20 to control the rotational speed of the blade 10 according to the wind speed detected by the anemometer 201, and the second The controller is a power converter controller 2000 that controls transmission power to the power grid 2 in accordance with the generated power command Pref output by the host controller 1000.

  The host controller 1000 receives the output v of the anemometer 201, the generated power value P calculated by the power converter controller 2000, and the blade rotation angular velocity ω, the pitch angle φref, and the generated power command value of the power converter 20. Pref is output.

  The pitch angle command φref calculated by the host controller 1000 is input to the pitch angle adjuster 12 via the pitch angle corrector 6000, which is a novel point of the present invention, and the pitch angle adjuster 12 adjusts the adjusted pitch angle command. Then, the pitch angle of the blade 10 is adjusted.

  The generated power command Pref calculated by the host controller 1000 is input to the power converter controller 2000. The power converter controller 2000 controls the converter 21 so that the active power received by the power converter 20 from the generator 15 matches the generated power command.

  The power converter 20 will be described in detail.

  The main circuit of the power converter 20 includes a converter 21, an inverter 22, a smoothing capacitor 22cdc, and harmonic filters 21fil and 22fil. The converter 21 has a function of controlling the power received from the generator 15 in accordance with the generated power command Pref output from the host controller 1000 and a function of controlling the reactive current received from the generator. The inverter 22 controls the voltage between the terminals of the smoothing capacitor 22cdc in accordance with a DC voltage command value that is a fixed value, thereby transmitting the generated power of the generator 15 received by the converter 21 to the power system 2, and the power system 2 Has a function of controlling the reactive current to be output.

  The configuration of main parts of the converter 21 and the inverter 22 will be described.

  In this embodiment, the configuration of the converter 21 and the inverter 22 will be described in the case of a 6-arm IGBT converter. The IGBT elements 21m to 21r and 22m to 22r constitute the arms of the converter 21 and the inverter 22, respectively. A gate drive signal is input from the power converter controller 2000 to the gate which is the control electrode of each of the IGBT elements 21m to 21r and 22m to 22r. By switching the IGBT elements by inputting a PWM-modulated gate drive signal, the AC output power of the generator 15 is converted into DC power, and the DC power is converted into AC power output to the power system 2.

  The output current of the generator 15 is determined by the difference between the generator induced voltage and the converter 21 output voltage, the leakage inductance of the generator 15 between them, and the inductance of the harmonic filter 21fil. The output current is converted into a direct current by the converter 21, and the smoothing capacitor 22cdc is charged by the direct current.

  The output current to the electric power system 2 is determined by the difference between the interconnection system voltage of the electric power system 2 and the output voltage of the inverter 22 and the impedance of the harmonic filter 22fil. The output current is converted from a direct current to an alternating current by switching of the inverter 22, and the smoothing capacitor 22cdc is discharged when the inverter 22 outputs active power to the system.

  The IGBT elements 21m to 21r and 22m to 22r generate a switching loss each time switching is performed. Further, when a current flows through the IGBT element, conduction loss occurs in the element. These losses increase the internal temperature of the IGBT element. When the junction temperature of the IGBT element becomes equal to or higher than a predetermined value, there is a possibility that the IGBT element is broken and the IGBT element is damaged. Further, even in circuit elements other than the IGBT element, for example, the reactors of the harmonic filters 21fil and 22fil, copper loss and iron loss occur due to current flow, and the temperature rises. If the temperature of the reactor rises abnormally, dielectric breakdown may occur, leading to damage to the power converter 20.

  The wind power generation system 1 of the present embodiment includes a cooling system 3 in order to avoid the damage due to the temperature rise, and the cooling water supplied by the cooling system 3 with the heat generated by the loss of the IGBT element and the harmonic filter. The temperature rise of the IGBT element and the harmonic filter is suppressed by cooling at.

  The cooling system 3 includes a heat exchanger 40 and a pump 41 that circulates cooling water between the heat exchanger 40, the converter 21, and the inverter 22. The cooling water sent out from the cooling system 3 flows from the cooling water piping 51 of the converter 21 and the inverter 22 to the cooling water piping 52 via the IGBT element and the water passage in the cooling fin of the harmonic filter, and again enters the cooling system 3. Return. The cooling water is forcibly circulated by a pump 41.

  The cooling water receives an amount of heat corresponding to the difference between the temperature of the IGBT element and the harmonic filter and the cooling water temperature in the process of flowing through the cooling fin water channels of the IGBT element and the harmonic filter. The cooling water is conveyed from the converter 21 or the inverter 22 to the heat exchanger 40 by the pump 41. At this time, the temperature of the cooling water rises due to the heat received from the IGBT element and the harmonic filter, and the temperature becomes higher than the outside air temperature. The heat exchanger 40 cools the cooling water by blowing the air around the heat exchanger 40 to the piping through which the cooling water flows. The cooling water cooled by the heat exchanger 40 flows again through the IGBT element and the harmonic filter of the converter 21 and the inverter 22 to cool the IGBT element and the harmonic filter, and makes the IGBT element and the harmonic filter excessive. Protects against destruction due to temperature rise.

  The power converter controller 2000 includes AC voltage values Vgu, Vgv, Vgw, Vsu, Vsv, Vsw detected by the AC voltage sensors 100, 101, AC current values Igu, Igv, Igw, Isu detected by the current sensors 103, 104. , Isv, Isw, and the DC voltage value Vdc detected by the DC voltage sensor 102 are input.

  The power converter controller 2000 calculates the power received from the generator 15 from the AC voltage value and the AC current value, and the AC of the converter 21 is set so that the detected AC power value matches the power command value received from the host controller 1000. Adjust the voltage.

  A detailed configuration of the power converter controller 2000 will be described with reference to FIG.

First, the power calculator 20006 calculates the effective power Pg received from the generator 15.
The active power controller 20001 obtains a deviation between the power command value and the calculated active power value, performs PI calculation so that the deviation becomes zero, and obtains an active current command value Idref that the converter 21 flows to the generator 15. calculate. A phase detector 20009 that detects the induced power phase of the generator 15 receives the generator terminal voltage detection values Vgu, Vgv, and Vgw as inputs, and calculates the phase estimation value θg of the induced voltage and the rotation angular velocity estimation value ω of the blade 10. The estimated phase value θg is output to the generator current controller 20003. The calculated active power value Pg received from the generator 15 and the estimated rotational angular velocity value ω of the blade 10 are output to the host controller 1000.

  The generator current controller 20003 receives the effective current command value Idref, the reactive current command value Iqref, the generator current detection values Igu, Igv, Igw, and the phase estimation value θg, and receives the effective current command value Idref and a predetermined invalidity. The generator current controller 20003 calculates a deviation between the current detection value and the generator current command value so that the current command value Iqref (here, zero) and the AC current detection value received from the generator 15 match. PI calculation is performed so that the deviation becomes zero, a generator-side AC voltage command value is determined, and this voltage command value is input to the PWM control block 20007 as a modulation wave. The PWM control block 20007 compares the modulated wave with the carrier wave, generates a gate drive signal, and outputs it to each gate of the IGBT elements 21m to 21r.

  When the IGBT elements 21m to 21r are turned on / off by a given gate signal, the converter 21 outputs a voltage corresponding to the AC voltage command value output by the generator current controller 20003 to the generator 15 side. Can do. As described above, the converter 21 can control the generated power of the generator 15 according to the power generation command value output from the host controller 1000.

  The power converter controller 2000 adjusts the AC voltage of the inverter 22 so as to control the voltage across the terminals of the smoothing capacitor 22cdc to a predetermined value.

  Specifically, first, the DC voltage sensor 102 detects the voltage across the terminals of the smoothing capacitor 22cdc. The DC voltage controller 20004 obtains a deviation between the predetermined value and the detected voltage value between the smoothing capacitor 22 cdc terminals, performs a PI operation so that the deviation becomes zero, and an effective current command output from the inverter 22 to the power system 2. The value Idref is calculated.

  The inverter current controller 20005 includes an active current command value Idref calculated by the DC voltage controller 20004, a predetermined reactive current command value Iqref (here, zero), an AC current detection value output to the power system 2, and a phase detector The system voltage phase θs output from 2001 is input. The inverter current controller 20005 calculates the deviation between the current detection value and the system current command value so that the current command value and the AC system detection value output to the power system 2 match, and sets the deviation to zero. PI calculation is performed to determine a system side AC voltage command value, and this voltage command value is input to the PWM control block 20008 as a modulated wave. The PWM control block 20008 compares the modulated wave with the carrier wave to create a gate drive signal and outputs it to each gate of the IGBT elements 22m to 22r.

  When the IGBT elements 22m to 22r are turned on / off by a given gate signal, the inverter 22 can output a voltage corresponding to the AC voltage command value output by the inverter current controller 20005 to the power system 2 side. it can. As described above, the inverter 22 adjusts the AC output voltage of the inverter 22 so that the DC voltage of the power converter 20 is controlled to be constant.

  Hereinafter, a blade over-rotation preventing mechanism by pitch angle correction according to the temperature detection value Tamb that is an output of the temperature sensor 200, which is a novel point of the present invention, will be described.

  The cooling capacity of the cooling water in the heat exchanger 40 depends on the difference between the cooling water temperature at the inlet of the cooling water heat exchanger 40 and the outside air temperature. When the outside air temperature becomes high, the cooling water cannot be cooled sufficiently. If the cooling water cannot be cooled sufficiently, the cooling water temperature at the outlet of the heat exchanger 40 increases, and as a result, the cooling capacity of the IGBT element and the harmonic filter by the cooling system 3 decreases.

  The over-rotation prevention mechanism of the present invention includes a temperature sensor 200 that indirectly detects a decrease in the cooling capacity of the cooling system 3, a cooling capacity detector 3000 that detects the cooling capacity according to the output of the temperature measuring means, and a pitch angle. It is comprised by the corrector 6000. When the cooling capacity of the cooling system 3 decreases, the over-rotation prevention mechanism adjusts the pitch angle to the feather side to limit the input energy due to wind. Thereby, even when the power that can be transmitted to the power system 2 by the power converter 20 is limited, the input energy due to wind can be reduced below the energy that can be transmitted by the power converter 20, thereby preventing blade over-rotation. can do.

  Hereinafter, the blade over-rotation preventing mechanism of this embodiment will be described in detail.

  The wind power generation system 1 includes a temperature sensor 200 that detects the outside air temperature. The temperature sensor 200 outputs a value Tamb that is directly proportional to the outside air temperature, and the output is input to the cooling capacity detector 3000. The outside air temperature detection location is desirably in the vicinity of the cooling system 3, and is preferably within the cooling system inlet 100m.

  The cooling capacity detector 3000 includes a cooling capacity detection table for Tamb as shown in FIG. That is, when the input Tamb from the temperature sensor 200 is higher than the predetermined value t1, the cooling capacity detector 3000 has a characteristic of monotonously decreasing the output of the detection means with respect to the input Tamb.

  Here, the output ΔS of the cooling capacity detector 3000 corresponds to a reduction range of power that the power converter 20 can transmit to the power system 2. The output signal of the cooling capacity detector 3000 is input to the pitch angle corrector 6000.

  The pitch angle corrector 6000 receives the pitch angle command φref from the host controller 1000 and the output ΔS of the cooling capacity detector 3000 and outputs the corrected pitch angle command φref2 to the pitch angle adjuster 12.

  A specific pitch angle correction method will be described with reference to FIG.

  The host controller 1000 receives the output v of the anemometer 201 and calculates a blade rotation speed command value ωref using a rotation speed command calculator 10001 that associates the anemometer output v with the wind speed and the rotation speed of the blade. Further, the rotational speed controller 10002 of the host controller 1000 receives the blade angular speed ω input from the power converter controller 2000 and the rotational speed command ωref, and inputs the pitch angle command value φref and the generated power command value Pref of the power converter 20. The pitch angle command value φref is output to the pitch angle corrector 6000 and the generated power command value Pref is output to the power converter controller 2000.

  Pitch angle corrector 6000 multiplies output ΔS of cooling capacity detector 3000 by gain K using multiplier 6001 and inputs the product to adder 6002. Here, the gain K is a gain for correcting the transmittable power reduction width ΔS of the power converter 20 to the pitch angle. When ΔS is negative, the pitch angle is changed to the feather side, and the rotation direction of the blade 10 is changed. Torque decreases. The gain K is designed so that the input energy due to wind becomes smaller than the power that can be generated by the power converter 20 by correcting the pitch angle.

  The adder 6002 adds the output of the multiplier 6001 to the pitch angle command φref input from the host controller 1000 and outputs the sum to the pitch angle adjuster 12 as a corrected pitch angle φref2.

  As described above, when the output of the temperature sensor 200 is higher than the predetermined value t1, the pitch angle command value φref2 of the blade 10 is corrected to the feather side, the torque input to the blade 10 by the wind is reduced, and the input of the wind power generation system Energy is reduced.

  An example of operation waveforms of the wind power generation system of the present embodiment is shown in FIG.

  The graph of FIG. 10 shows temporal changes of the temperature sensor 200 detected value Tamb, the transmittable power reduction width ΔS, the pitch angle command φref2, the blade rotation angular velocity ω, and the generator generated power P in order from the top.

  At time time1, the temperature sensor 200 exceeds the predetermined determination temperature t1. In the wind power generation system 1 of the present invention, the cooling capacity detector 3000 detects that the output value of the temperature sensor 200 exceeds the predetermined temperature t1, and outputs the transmittable power reduction width ΔS to the pitch angle corrector 6000. The pitch angle corrector 6000 changes the pitch angle command value φref output from the host controller 1000 in accordance with ΔS, changes the pitch angle command value φref2 in the minus direction on the feather side, and outputs it to the pitch angle adjuster 12. Since the pitch angle adjuster 12 adjusts the pitch in accordance with the command value φref2, the torque in the rotational direction applied to the blade 10 decreases.

  The rotational direction torque of the blade 10 decreases, and the electric power received by the power converter 20 from the generator 15 does not change at time time 1, so the rotational angular velocity ω of the blade 10 decreases transiently.

  The host controller 1000 detects a decrease in the rotational angular velocity ω and decreases the generated power command value Pref of the power converter 20 so that the rotational angular velocity matches the command value ωref.

  The power converter controller 2000 reduces the generated power P in accordance with Pref. Since the generated power amount P is reduced, heat generation due to loss inside the power converter 20 is reduced, and the power converter 20 can continue to operate.

  Since the power converter 20 can continue to operate, the blade 10 is subjected to load torque generated by the power generation of the generator 15, so that over-rotation can be avoided without causing the rotation angular velocity ω of the blade 10 to rapidly increase.

  In this embodiment, the temperature sensor 200 estimates the decrease in the cooling capacity of the cooling system 3 by detecting the outside air temperature with the temperature sensor 200. However, as shown in FIG. 6, the temperature sensor 200 determines the cooling water temperature at the outlet of the cooling system 3. It is also possible to detect and estimate a decrease in cooling capacity of the cooling system 3 using the detected value.

  Further, the temperature sensor 200 may detect the cooling water temperature at the inlet of the cooling system 3 as shown in FIG. 7 and estimate the cooling capacity of the cooling system 3 using the detected value.

  Moreover, although the power converter of a present Example was a water cooling type power converter which cools the IGBT element and harmonic filter reactor which are elements with big heat_generation | fever using cooling water, it is a cooling fan 50 as shown in FIG. It may be a forced air-cooled power converter using. In this configuration, it is desirable that the IGBT element includes a cooling fin for increasing the contact area with the cooling air. In this case, the temperature sensor may detect the cooling air inlet temperature, or may detect the air temperature of the cooling air outlet.

  In the present embodiment, the cooling capacity detector 3000 is not included in the power converter controller 2000, but the power transmission available power reduction width may be calculated in the power converter controller 2000 as shown in FIG. .

  As described above, the wind power generation system according to the present embodiment is capable of limiting the input energy due to the wind and continuing the operation of the power converter even if the cooling capacity of the power converter is reduced due to an increase in the outside air temperature. The blade can be prevented from over-rotating.

  In this embodiment, an example of the wind power generation system 1 that detects the cooling capacity based on the internal temperature of the power converter will be described.

  FIG. 11 is an example of a configuration diagram illustrating the wind power generation system 1 according to the first embodiment.

  In the wind power generation system 1 of FIG. 1, the description of the components having the same functions as those already described with reference to FIG. 1 is omitted.

  The difference between the present embodiment and the wind power generation system described in the first embodiment is that the temperature sensor 200 is installed in a housing that houses the converter 21 and the inverter 22 of the power converter 20.

  In the first embodiment, the temperature of the cooling water is detected directly or indirectly by detecting the ambient temperature, thereby detecting a decrease in the cooling capacity of the cooling system 3 that cools the power converter 20. Is for estimating the cooling capacity drop of the cooling system 3 by detecting the temperature in the housing of the power converter 20 and correcting the pitch angle command value of the blade 10.

  With this configuration, it is possible to directly detect the imbalance between heat generation due to internal loss of the power converter 20 and heat release due to cooling, so that tripping of the power converter 20 can be avoided and, as a result, over-rotation of the blade 10 is prevented. can do.

  Hereinafter, the wind power generation system of a present Example is demonstrated using FIG. 11, FIG.

  In FIG. 11, the power converter 20 and the cooling system 3 of the wind power generation system of a present Example are shown. The power converter 20 is connected to the generator 15 via the power cable 25 and to the transformer 30 via the power cable 26. Blades, hubs, shafts, generators, nacelles, towers, transformers, and a power system (not shown) are the same as those of the wind power generation system 1 shown in the first embodiment.

  FIG. 12 shows details of the wind power generation system of the present embodiment.

  In the wind power generation system of the present embodiment, the power converter 20 includes a housing 10000, and includes a converter 21 and an inverter 22 in the housing. In the wind power generation system according to the present embodiment, the temperature sensor 200 is provided not in the vicinity of the cooling system 3 but in the housing 10000.

  When the cooling capacity of the cooling system 3 that cools the power converter 20 decreases due to an increase in the outside air temperature, the heat generated by the loss in the power converter 20 exceeds the amount of heat extracted by the cooling system 3 to the outside of the housing 10000, and the power conversion The internal temperature of the vessel 20 rises. The temperature sensor 200 detects the temperature in the panel and outputs the detected temperature Tamb to the cooling capacity detector 3000.

  Since the temperature sensor 200 is intended to detect the balance between heat generation in the housing and heat radiation by cooling, it is desirable that the temperature sensor 200 be provided on the top of the housing. Specifically, it is desirable to be provided in a place that is 1/2 or more higher in the height direction of the housing.

  FIG. 12 shows the relationship between the temperature sensor 200 and the wind power generation system controller.

  The in-casing temperature Tamb detected by the temperature sensor 200 is input to the power converter controller 2000, and the power converter controller 2000 performs the same calculation as that of the cooling capacity detector 3000 described in the first embodiment, and the transmission power reduction width ΔS. Is output to the pitch angle corrector 6000.

  By adopting this configuration, the wind power generation system according to the present embodiment can detect a temperature rise in the housing of the power converter 20 and correct the pitch angle of the blade 10, so that the generated power command to the power converter 20 can be corrected. And the heat generation of the power converter 20 is reduced. By reducing the heat generation, the operation of the power converter 20 can be continued while avoiding the overheating of the power converter 20, and therefore, the blade 10 can be prevented from over-rotating.

  As described above, the wind power generation system according to the present embodiment is capable of limiting the input energy due to the wind and continuing the operation of the power converter even if the cooling capacity of the power converter is reduced due to an increase in the outside air temperature. The blade can be prevented from over-rotating.

  Furthermore, according to the present embodiment, by detecting the temperature in the casing of the power converter 20, heat generation due to loss in the power converter 20 and cooling imbalance between the cooling system 3 of the power converter 20 are detected. Therefore, it is possible to detect a decrease in the cooling capacity of the cooling system 3 more reliably, and to continue the operation of the power converter 20, and as a result, it is possible to avoid over-rotation of the blade 10.

  In this embodiment, an example of the wind power generation system 1 that detects the cooling capacity based on the internal temperature of the power converter will be described.

  FIG. 13 is an example of a configuration diagram illustrating the wind power generation system 1 according to the first embodiment.

  In the wind power generation system 1 of FIG. 1, the description of the components having the same functions as those already described with reference to FIG. 1 is omitted.

  The difference between the present embodiment and the wind power generation system described in the second embodiment is that the temperature sensor 200 is installed on the cooling fin of the semiconductor element of the power converter 20.

  In a water-cooled power converter, the junction temperature of the semiconductor element exceeds the allowable value before the temperature in the housing rises to a detectable level when the cooling fins have a short thermal time constant and the cooling capacity of the cooling system 3 decreases. There is a possibility of causing element destruction. The temperature of the cooling fin is detected by the temperature sensor 200, and when the detected temperature becomes higher than the predetermined temperature t1, the pitch angle of the blade 10 is adjusted to the feather side, so that the power converter 20 is heated before the semiconductor element is overheated. Since the generated power can be reduced, the operation of the power converter 20 can be continued while protecting the semiconductor element more reliably. Since the power converter 20 can continue to operate, the blade 10 can generate a torque that decelerates the rotation of the blade 10 by the power generated by the power converter 20, and as a result, the blade 10 can be prevented from over-rotating.

  Hereinafter, the wind power generation system of the present embodiment will be described with reference to FIG.

  In FIG. 13, the energy transmission part of the wind power generation system 1 is shown. Here, the nacelle 60 and the tower 70 (not shown) are the same as those described in the first and second embodiments.

  The power converter 20 of the present embodiment includes a temperature sensor 200 in contact with the cooling fin of the semiconductor element 22q. The output Tamb of the temperature sensor 200 is input to the power converter controller 2000. In the controller, the same calculation as that of the cooling capacity detector 3000 described in the first embodiment is performed, and the calculated value of the transmittable power reduction width ΔS is output to the pitch angle corrector 6000.

  The pitch angle corrector 6000 receives the transmittable power reduction width ΔS output from the power converter controller 2000 and corrects the pitch angle command value in the same manner as the calculation of the pitch angle corrector 6000 of the first and second embodiments. Then, the pitch angle command value φref2 as the output is transmitted to the pitch angle adjuster 12.

  With the above configuration, the wind power generation system 1 according to the present embodiment detects the temperature of the cooling fin of the semiconductor element by the temperature sensor 200, and if the temperature of the cooling fin is equal to or higher than a predetermined value, the pitch angle of the blade 10 is set to the feather side. Correction is performed to reduce the generated power of the power converter 20 and to allow the power converter 20 to continue operating while avoiding overheating of the semiconductor elements of the power converter 20.

  Since the power converter 20 continues to operate, a torque in the direction of decelerating the rotation of the blade 10 is applied, so that the blade 10 can be prevented from over-rotating.

  As described above, the wind power generation system according to the present embodiment is capable of limiting the input energy due to the wind and continuing the operation of the power converter even if the cooling capacity of the power converter is reduced due to an increase in the outside air temperature. The blade can be prevented from over-rotating.

  Furthermore, according to the present embodiment, the pitch angle can be corrected using the cooling fin detection temperature of the semiconductor element, so that the operation of the power converter 20 can be continued while the semiconductor element is more reliably protected from overheating. As a result, the blade Ten over-rotations can be avoided.

  In this embodiment, an example of the wind power generation system 1 that detects the cooling capacity based on the internal temperature of the harmonic filter will be described.

  FIG. 14 is an example of a configuration diagram illustrating the wind power generation system 1 according to the first embodiment.

  In the wind power generation system 1 of FIG. 1, the description of the components having the same functions as those already described with reference to FIG. 1 is omitted.

  The difference between the present embodiment and the wind power generation system described in the embodiment 2 or 3 is that the temperature sensor 200 is installed on the cooling fin of the harmonic filter 22fil.

  In the water-cooled harmonic filter as in the third embodiment, the thermal time constant of the cooling fin is short, and when the cooling capacity of the cooling system 3 is reduced, before the temperature in the housing rises to be detectable, There is a possibility that the temperature exceeds an allowable value, dielectric breakdown occurs, and the power converter 20 is damaged. Accordingly, the cooling fin temperature of the harmonic filter is detected by the temperature sensor 200, and the pitch angle of the blade 10 is adjusted to the feather side when the detected temperature becomes higher than the predetermined temperature t1, so that the filter element is overheated. In addition, since the generated power of the power converter 20 can be reduced, the operation of the power converter 20 can be continued while protecting the filter element more reliably. Since the power converter 20 can continue to operate, the blade 10 can generate a torque that decelerates the rotation of the blade 10 by the power generated by the power converter 20, and as a result, the blade 10 can be prevented from over-rotating.

  Hereinafter, the wind power generation system of the present embodiment will be described with reference to FIG.

  In FIG. 14, the energy transmission part of the wind power generation system 1 is shown. Here, the nacelle 60 and the tower 70 (not shown) are the same as those described in the first to third embodiments.

  The power converter 20 of the present embodiment includes a temperature sensor 200 in contact with the cooling fin of the harmonic filter 22fil. In addition, it is good also as a structure provided with the temperature sensor 200 in the cooling fin of the harmonic filter 21fil. The output Tamb of the temperature sensor 200 is input to the power converter controller 2000. In the controller, the same calculation as that of the cooling capacity detector 3000 described in the first embodiment is performed, and the calculated value of the transmittable power reduction width ΔS is output to the pitch angle corrector 6000.

  The pitch angle corrector 6000 receives the transmittable power reduction width ΔS output from the power converter controller 2000 and corrects the pitch angle command value in the same manner as the calculation of the pitch angle corrector 6000 of the first to third embodiments. The output pitch angle command value φref 2 is transmitted to the pitch angle adjuster 12.

  With the above configuration, the wind power generation system 1 of the present embodiment detects the temperature of the cooling fins of the harmonic filter 22fil by the temperature sensor 200, and if the temperature of the cooling fins is equal to or higher than a predetermined value, the pitch angle of the blade 10 is set to the feather side. To reduce the generated power of the power converter 20 and to allow the power converter 20 to continue operating while avoiding overheating of the filter element of the power converter 20.

  Since the power converter 20 continues to operate, a torque in the direction of decelerating the rotation of the blade 10 is applied, so that the blade 10 can be prevented from over-rotating.

  As described above, the wind power generation system according to the present embodiment is capable of limiting the input energy due to the wind and continuing the operation of the power converter even if the cooling capacity of the power converter is reduced due to an increase in the outside air temperature. The blade can be prevented from over-rotating.

  Furthermore, according to the present embodiment, the pitch angle can be corrected using the cooling fin detection temperature of the filter element, so that the operation of the power converter 20 can be continued while protecting the filter element from overheating more reliably. As a result, the blade Ten over-rotations can be avoided.

  In the present embodiment, an example of the wind power generation system 1 that detects the cooling capacity based on the internal temperature of the cooling fins other than the cooling fins of the semiconductor element and the harmonic filter will be described.

  FIG. 15 is an example of a configuration diagram illustrating the wind power generation system 1 according to the first embodiment.

  In the wind power generation system 1 of FIG. 1, the description of the components having the same functions as those already described with reference to FIG. 1 is omitted.

  The difference between the present embodiment and the wind power generation systems described in Embodiments 2 to 4 is that the temperature sensor 200 is installed on a cooling fin other than the cooling fins of the semiconductor element and the harmonic filter.

  Although the thermal time constant of the cooling fin is longer than that of the water-cooled semiconductor element and the harmonic filter as compared with the third to fourth embodiments, the temperature inside the casing rises to be detectable when the cooling capacity of the cooling system 3 is reduced. As a result, it is possible to detect a reduction in the cooling capacity earlier, and it is not necessary to attach the temperature sensor 200 to individual semiconductor elements and harmonic filters as compared with the third and fourth embodiments, so that the cost can be reduced. Furthermore, it is possible to manage in a unified manner as compared with the embodiment in which the temperature sensor 200 is attached to individual semiconductor elements and harmonic filters. As a result, the temperature inside the cooling fin is detected by the temperature sensor 200 before the temperature of the semiconductor element or the filter element exceeds the allowable value, and the pitch angle of the blade 10 when the detected temperature becomes higher than the predetermined temperature t1. By adjusting to the feather side, the generated power of the power converter 20 can be reduced before the semiconductor element or the filter element is overheated.

  And the operation | movement of the power converter 20 can be continued, protecting a semiconductor element and a filter element more reliably. Since the power converter 20 can continue to operate, the blade 10 can generate a torque that decelerates the rotation of the blade 10 by the power generated by the power converter 20, and as a result, the blade 10 can be prevented from over-rotating.

  Hereinafter, the wind power generation system of the present embodiment will be described with reference to FIG.

  In FIG. 15, the energy transmission part of the wind power generation system 1 is shown. Here, the nacelle 60 and the tower 70 (not shown) are the same as those described in the first to fourth embodiments.

  The power converter 20 of the present embodiment includes a temperature sensor 200 that contacts a cooling fin other than the cooling fins of the semiconductor element and the harmonic filter. The output Tamb of the temperature sensor 200 is input to the power converter controller 2000. In the controller, the same calculation as that of the cooling capacity detector 3000 described in the first embodiment is performed, and the calculated value of the transmittable power reduction width ΔS is output to the pitch angle corrector 6000.

  The pitch angle corrector 6000 receives the transmittable power reduction width ΔS output from the power converter controller 2000 and corrects the pitch angle command value in the same manner as the calculation of the pitch angle corrector 6000 of the first to fourth embodiments. The output pitch angle command value φref 2 is transmitted to the pitch angle adjuster 12.

  With the above configuration, the wind power generation system 1 of the present embodiment detects the temperature of the cooling fins other than the cooling fins of the semiconductor element and the harmonic filter by the temperature sensor 200, and if the temperature of the cooling fin is equal to or higher than a predetermined value, The pitch angle is corrected to the feather side to reduce the generated power of the power converter 20, and the operation of the power converter 20 can be continued while avoiding overheating of the semiconductor element and the filter element of the power converter 20.

  Since the power converter 20 continues to operate, a torque in the direction of decelerating the rotation of the blade 10 is applied, so that the blade 10 can be prevented from over-rotating.

  As described above, the wind power generation system according to the present embodiment is capable of limiting the input energy due to the wind and continuing the operation of the power converter even if the cooling capacity of the power converter is reduced due to an increase in the outside air temperature. The blade can be prevented from over-rotating.

  Furthermore, according to the present embodiment, the pitch angle can be corrected using the cooling fin detection temperature of the filter element, so that the operation of the power converter 20 can be continued while protecting the filter element from overheating more reliably. As a result, the blade Ten over-rotations can be avoided.

  FIG. 16 illustrates a state before and after the pitch angle of the blade 10 according to the present invention is variably controlled.

  First, how to obtain wind power from the wind turbine including the blade 10 will be described. When the wind 80 hits the blade 10, a relative air flow is generated around the blade 10, and this air flow is Since the speed is different between the windward 81 and the leeward 82, a pressure difference is generated due to the difference in speed. The pressure difference becomes lift 83 and the blade rotates about the rotation surface 84.

  In order to vary this rotational speed, by changing the pitch angle, which is the mounting angle of the blade, the flow velocity of air around the blade changes and the lift also changes.

  Specifically, when the output voltage possible amount of the power converter is decreased due to a decrease in the cooling function, the pitch angle 86 of the blade before the pitch angle control in FIG. The blade is adjusted to be as large as the pitch angle 87 of the blade and to be parallel to the direction of the wind 80 hitting the blade. This reduces the lift on the blade and reduces the rotational force.

  As a result, it is possible to control the input energy from the blade in accordance with the power that can be transmitted, and to prevent over-rotation of the blade and failure of the power converter.

DESCRIPTION OF SYMBOLS 1 Wind power generation system 2 Electric power system 3 Cooling system 10 Blade 11 Hub 12 Pitch angle adjuster 13 Shaft 14 Gear 15 Generator 20 Power converter 21 Converter 21up, 21un, 21vp, 21vn, 21wp, 21wn, 22up, 22un, 22vp, 22vn, 22wp, 22wn Semiconductor switching element 21fil, 22fil Harmonic filter 22 Inverter 22cdc Smoothing capacitor 23 Electromagnetic contactor 24 Power converter inlet 25, 26 Power cable 30 Transformer 40 Heat exchanger 41 Pump 50 Cooling fan 60 Nacelle 70 Tower 80 Wind 81 Windward 82 Windward 83 Lifting force 84 Rotating surface 85 Blade angle 86, 87 Pitch angle 100, 101 AC voltage sensor 102 DC voltage sensor 103, 104 Current sensor 200 Temperature sensor 201 Wind Total 300, 6002 Adder 1000 Host controller 2000 Power converter controller 3000 Cooling capacity detector 6000 Pitch angle corrector 6001 Multiplier 10000 Housing 100001 Rotational speed command calculator 10002 Rotational speed controller 20001 Active power controller 20002 Terminal voltage controller 20003 Generator current controller 20004 DC voltage controller 20005 Inverter current controller 20006 Power calculator 20007, 20008 PWM control block 20009, 201010 Phase detector

Claims (11)

A converter that converts variable frequency generated power output from a synchronous generator mechanically connected to a variable pitch angle blade to DC power;
A smoothing capacitor for smoothing the DC power output from the converter;
An inverter that is electrically connected to a power system, converts the DC power from the converter to the fixed frequency AC power through the smoothing capacitor, and outputs the AC power to the power system;
A pitch angle command value calculating means for calculating a pitch angle command value for performing variable control of the pitch angle of the blade, and performing a command to mechanically adjust the pitch angle from the pitch angle command value;
A cooling system for cooling the converter and the inverter;
A wind power generation system having
A cooling capacity detecting means for detecting a cooling capacity of the cooling system or a cooling state of a power converter including the converter and the inverter;
Pitch angle command value correcting means for correcting the pitch angle command value calculated by the pitch angle command value calculating means,
Based on the detection result of the cooling capacity detecting means, the pitch angle command value correcting means corrects the pitch angle command value, and variably controls the pitch angle of the blade according to the corrected pitch angle command value. A wind power generation system characterized by performing a command. The wind power generation system according to claim 1,
The cooling capacity detecting means is
A temperature sensor that detects a temperature inside or outside the wind power generation system is provided, and a reduction range of power that can be transmitted from the power converter to the power system based on a detection result of the temperature sensor. A wind power generation system characterized by estimating. The wind power generation system according to claim 2,
The cooling capacity detecting unit further includes a data table in which a predetermined temperature is set in advance, and the power reduction range is increased as the temperature detected by the temperature sensor becomes higher than the temperature set in the data table. A wind power generation system characterized by monotonically decreasing estimation. The wind power generation system according to claim 2 or 3,
The pitch angle command value correction means obtains a correction value of the pitch angle command value based on the reduction range of the electric power output from the cooling capacity detection means, and adds the pitch angle command value and the correction value. Thus, the corrected pitch angle command value is output. The wind power generation system according to claim 4,
Pitch angle adjusting means for mechanically adjusting the pitch angle from the pitch angle command value is provided, and the pitch angle adjusting means variably controls the pitch angle of the blade based on the corrected pitch angle command value. Wind power generation system characterized by A wind power generation system according to any one of claims 2 to 5,
The temperature sensor is provided in the cooling system or outside the cooling system, and detects a temperature inside the cooling system or outside the cooling system. A wind power generation system according to any one of claims 2 to 5,
The temperature sensor is
A wind power generation system that is provided inside or outside a housing that houses the power converter, and detects an air temperature inside or outside the housing. The wind power generation system according to any one of claims 1 to 7,
The cooling system further cools a harmonic filter reactor provided between the synchronous generator and the converter, and between the inverter and the power system, and the cooling capacity detecting means is configured to detect the harmonic filter of the cooling system. A wind power generation system characterized by detecting a cooling capacity for a reactor or a cooling state of the harmonic filter reactor. The wind power generation system according to any one of claims 1 to 8,
The cooling system includes a heat exchanger that releases heat to the converter or the inverter using cooling air, and a fan that circulates the cooling air. The wind power generation system according to any one of claims 1 to 8,
The cooling system includes: a heat exchanger that releases heat of cooling water that has received heat from the power converter; a pump for sending cooling water between the heat exchanger and the power converter; A cooling water pipe for distributing the cooled cooling water between the heat exchanger and the power converter, and a cooling fin water path for circulating the cooling water distributed from the cooling water pipe into the power converter. Wind power generation system characterized by The wind power generation system according to claim 10,
The wind power generation system characterized by detecting the temperature of the cooling water in the cooling water pipe or the cooling fin water channel by the temperature sensor.