JP2005218163A - Turbine power generation apparatus and independent operation method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a self-sustained operation excellent in output responsiveness to a load change without requiring an expensive protective device and without providing a power storage element in a turbine power generator.
In a turbine power generator 1 that converts power generated by a turbine generator 4 into DC power by a converter 5, further converts DC power output from the converter into AC power by an inverter 7, and outputs the AC power to a load. When the voltage supplied to the inverter via the voltage is equal to or lower than the first voltage value Vc1 determined in advance, the voltage supplied from the system 8 to the inverter and supplied from the turbine generator via the converter to the second voltage determined in advance When the voltage value is equal to or higher than Vc2, the regenerative resistor 11 consumes surplus power, thereby controlling the voltage input to the inverter to be Vc1 to Vc2. By stabilizing the input voltage to the inverter, high-speed control of the inverter output with respect to load fluctuations becomes possible.
[Selection] Figure 1

Description

  The present invention relates to a turbine power generation apparatus that generates power by driving a permanent magnet synchronous generator by a gas turbine, and a self-sustained operation method thereof.

  In a turbine generator in which a gas turbine and a synchronous generator are directly connected, such as a micro gas turbine, the power generation frequency is obtained by multiplying the rotation speed of the gas turbine (hereinafter sometimes referred to as the rotation speed) by the number of pole pairs of the generator. Thus, electric power having a frequency higher than the commercial frequency (50 or 60 Hz) is generated. For example, a 2-pole generator (the number of pole pairs is 1) directly connected to a gas turbine of 60,000 rpm generates 1 kHz of power. Such a high-speed rotating generator uses a generator using a strong rare earth permanent magnet as a magnetic pole of the rotor in order to make it strong enough to withstand centrifugal force, and to reduce the size and increase the power density. That is, unlike a generator having a field winding, a permanent magnet type synchronous generator is a generator that cannot manipulate the strength of a magnetic field, that is, cannot control a generated voltage. In order to use this power generation output, it is necessary to convert it into a commercial frequency (50 or 60 Hz) and voltage (for example, three-phase 220 V). This power conversion is performed by once converting to direct current by a rectifier circuit such as a converter (abbreviated as CNV) and then converting the direct current power into alternating current of a required frequency and voltage by an inverter (abbreviated as INV).

  In general, such a turbine power generator is inferior in output response characteristics with respect to load fluctuations. For example, in the case of a micro gas turbine of a grid interconnection machine, it takes 1 minute to raise the output from zero (0)% to 100%. Turbine power generators connected to the grid are operated so that only the power of the base load is supplied by the turbine power generator, and the shortage of the power generated by the power generator with respect to load fluctuations is caused by the power supply from the grid. Corresponding. Therefore, the output responsiveness of the gas turbine power generation device with respect to load fluctuations is not required.

  However, in the grid connection operation, when the power generated by the turbine power generator exceeds the required power of the load in accordance with the load variation, surplus power generated by the turbine power generator is supplied to the system. Since the grid is often a commercial power source in many cases, in order to prevent troubles due to overcurrent, overvoltage, frequency fluctuation, etc. caused by the power supplied from the turbine power generator to the grid, the grid and the turbine power generator There is a problem that it is necessary to install a protective device that can be disconnected. Further, as described above, since the grid is a commercial power source, that is, an asset of the electric power company, there is a problem that it is necessary to negotiate with the electric power company in advance in order to link the turbine power generation device to the grid. As described above, the connection between the turbine power generation device and the system requires an expensive protective device, and the need for consultation in advance to obtain the consent of the electric power company hinders the spread of the turbine power generation device. ing.

  In the conventional technology that solves such problems and does not use interconnection with the grid, a power storage element is provided in the turbine power generation device, and the load fluctuation component in the region where the output control of the turbine power generation device cannot follow the power storage element Is absorbed by charging / discharging (see Patent Document 1).

  However, for example, a secondary battery, which is a representative example of a power storage element, has a relatively short life, and when a power generation device including the secondary battery is provided in a package, an appropriate temperature range is required to sufficiently develop the power storage function. It must be managed to become. Further, when the secondary battery is a lead storage battery, a lithium ion battery, a nickel metal hydride battery, or the like, there is a problem that disposal is difficult because a substance having a high environmental load is included. Further, when operating a turbine power generation device provided with a power storage element, an operation for charging the power storage element is essential, and the gas turbine cannot be stopped for ten minutes during the charging. is there.

JP-T-2001-527180

  An object of the present invention is to provide a turbine power generator excellent in output responsiveness to load fluctuations and a self-sustaining operation method thereof without requiring an expensive protective device and without providing a power storage element.

The present invention includes (a) a turbine generator in which a permanent magnet synchronous generator is connected to a gas turbine whose output can be controlled by a fuel flow rate;
(B) a converter connected to the turbine generator;
(C) an inverter connected between the converter and the load;
(D) transforming means connected to the AC interconnection system;
(E) rectifying means connected between the transformer means and the inverter;
(F) including a regenerative resistor connected to a direct current part that is an output part from the converter,
(G) In a state where the voltage fed from the turbine generator to the inverter via the converter is equal to or lower than the first voltage value determined in advance, the inverter is fed from the AC interconnection system via the transformer means and the rectifier means,
(H) A turbine power generator configured to consume surplus power by a regenerative resistor when a voltage fed from a turbine generator to an inverter via a converter is equal to or higher than a predetermined second voltage value. Device.

The present invention also includes: (a) a turbine generator in which a permanent magnet synchronous generator is connected to a gas turbine whose output can be controlled by a fuel flow rate;
(B) a converter connected to the turbine generator;
(C) an inverter connected between the converter and the load;
(D) a PWM converter connected between the AC interconnection system and the inverter;
(E) a limiter that is connected to the PWM converter and limits the output direction of the PWM converter to a direction from the AC interconnection system to the inverter;
(F) including a regenerative resistor connected to a direct current part that is an output part from the converter,
(G) In a state where the voltage supplied from the turbine generator to the inverter via the converter is equal to or lower than a predetermined first voltage value, the inverter is supplied from the AC interconnection system via the PWM converter,
(H) Turbine power generation configured to consume surplus power by regenerative resistance in a state where the voltage fed from the turbine generator through the converter to the inverter is equal to or higher than a predetermined second voltage value Device.

The present invention also generates power by driving a permanent magnet synchronous generator connected to a gas turbine whose output can be controlled by the fuel flow rate, converts the generated power into DC power by a converter, and outputs DC power from the converter. In the self-sustaining operation method of the turbine generator that further converts the AC power into the AC power by the inverter and supplies power to the load,
When the voltage supplied to the inverter through the converter from the turbine generator in which the permanent magnet type synchronous generator is connected to the gas turbine is equal to or lower than a predetermined first voltage value, the inverter is supplied from the AC interconnection system, When the voltage supplied to the inverter from the turbine generator through the converter is equal to or higher than a predetermined second voltage value, by consuming excess power with the regenerative resistor,
It is a self-sustaining operation method of a turbine power generator characterized by controlling the voltage inputted into an inverter so that it may become the range which exceeds the 1st voltage value and is less than the 2nd voltage value.

In the present invention, the output control of the gas turbine by the fuel flow rate is
At startup,
Based on a predetermined relationship between the fuel flow rate and the rotational speed of the gas turbine, the fuel flow rate is charged so that the gas turbine has a predetermined rotational speed.
When driving after startup,
The exhaust gas temperature EGT of the gas turbine is detected, the gas turbine rotation speed determined in advance corresponding to the magnitude of the load, the preset exhaust gas temperature SEGT predetermined to correspond to the gas turbine rotation speed, and the detected exhaust gas temperature EGT The fuel flow rate necessary for changing the rotational speed so that the deviation ΔT (= SEGT−EGT) of
DC voltage Vdc output from the converter to the inverter is detected, and the rotational speed is changed so that the deviation ΔV (= Vs−Vdc) of the detected voltage value Vdc with respect to the predetermined voltage setting value Vs becomes zero. Of the fuel flow required for
It is characterized by being performed by selecting whichever fuel flow rate is smaller.

  According to the present invention, when the power generated by the turbine generator is insufficient with respect to an increase in load, power is supplied from the system via the transformer means and the rectifier means, and the power generated by the turbine generator is decreased with respect to the decrease in load. When excessive, excess power is not consumed by the regenerative resistor and returned to the grid. In this way, only power is supplied from the system, and no surplus power is supplied to the system, so that a protective device is not required. Further, it is possible to realize a turbine power generator having excellent output responsiveness to load fluctuations without providing a power storage element for absorbing load fluctuations in a region where output control cannot follow. Further, since the power storage element is not included, it is not necessary to charge the power storage element when stopping the turbine power generation device, and the power storage element can be stopped immediately, so that unnecessary fuel consumption can be suppressed.

  Further, according to the present invention, voltage control of the DC portion can be realized with higher accuracy by supplying power from the system to the inverter via the PWM converter.

  Further, according to the present invention, when the voltage fed from the turbine generator to the inverter through the converter is equal to or lower than a predetermined first voltage value, the power is fed from the system to the inverter, and from the turbine generator to the inverter through the converter. When the supplied voltage is equal to or higher than the predetermined second voltage value, excess power is consumed by the regenerative resistor, so there is no need to provide a protection device for protecting the system, and the area where output control cannot follow Without the need for a power storage element to absorb the load fluctuations, the voltage input to the inverter is accurately stabilized so that it exceeds the first voltage value and falls below the second voltage value. Thus, a self-sustaining operation method of a turbine power generator excellent in responsiveness of an inverter output to a load change is provided.

  FIG. 1 is a system diagram showing a simplified configuration of a turbine power generator 1 according to an embodiment of the present invention, and FIG. 2 is a diagram showing a circuit of a main part of the turbine power generator 1 shown in FIG. The turbine generator 1 includes a gas turbine 2 whose output can be controlled by a fuel flow rate, a turbine generator 4 in which a permanent magnet type synchronous generator 3 is connected, a converter 5 connected to the turbine generator 4, a converter 5, An inverter 7 connected between the load 6, a transforming means 9 connected to an AC interconnection system 8 (hereinafter simply referred to as the system 8), and between the transforming means 9 and the inverter 7. It includes a rectifying means 10 to be connected and a regenerative resistor 11 connected to a DC unit 37 that is an output unit from the converter 5.

  The gas turbine 2 includes a turbine 21, an air compressor 22, and a combustor 23. Fuel is supplied to the combustor 23 from a fuel source 24 through a shutoff valve 25 and a gas compressor 26 that controls the fuel supply flow rate, and compressed air is supplied from an air compressor 22. By burning the fuel in the combustor 23 to generate high-temperature and high-pressure combustion gas, the turbine 21 is driven, and the difference between the power generated by the turbine 21 and the driving force of the air compressor 22 is a permanent magnet type as a shaft output. Used to drive the synchronous generator 3. The output of the gas turbine 2 is controlled in rotation speed (= rotation speed) by the gas compressor controller 27 controlling the operation of the gas compressor 26 and adjusting the flow rate of the fuel gas in accordance with a control method described later.

  The permanent magnet type synchronous generator 3 includes a rotor 28 having a permanent magnet and a stator 29 having a field coil. The rotor 28 is directly connected to the output shaft of the gas turbine 2 and is driven to rotate. An induced voltage having a frequency corresponding to the rotation speed is generated. Further, when AC power is supplied to the field coil and excited, the permanent magnet synchronous generator 3 operates as the synchronous motor 3a, generates torque, and can start the rotation of the gas turbine 2. .

  The field coil of the permanent magnet type synchronous generator 3 has, for example, a star shape and is connected to the converter 5 via lines 31, 32 and 33. The converter 5 has a converter bridge circuit 36 connected between the lines 34 and 35. The converter bridge circuit 36 includes switching transistors Q1c, Q2c; Q3c, Q4c; Q5c, Q6c for each phase connected in series between the lines 34, 35, and is connected to the lines 31, 32, 33. .

  The lines 34 and 35 are provided with a direct current section 37 and further provided with an inverter 7. The inverter 7 has an inverter bridge circuit 38 connected between the lines 34 and 35. This inverter bridge circuit 38 is similar to the converter bridge circuit 36 described above, and includes inverter switching transistors Q1i, Q2i; Q3i, Q4i; Q5i, Q6i connected in series for each phase, 40, 41. Switching transistors Q1c to Q6c and Q1i to Q6i may be realized by a switching element other than a transistor having a control terminal that performs an on / off switching operation. These lines 39, 40 and 41 are connected to the load 6 through the reactor 42 and the electromagnetic contactor 43. A voltage sensor 46 that detects the voltage Vdc of the DC unit 37 is connected to the lines 34 and 35 of the DC unit 37, and may include capacitors 44 and 45.

  The converter 5 converts the AC power output from the turbine generator 4 to DC and outputs it to the DC unit 37, and the inverter 7 converts the DC power input from the DC unit 37 to AC, for example, AC 220V, It outputs to the load 6 as alternating current power of frequency 60Hz.

  The transforming means 9 connected to the system 8 is a step-up transformer, and the rectifying means 10 is a three-phase full-wave rectifier (hereinafter simply referred to as a rectifier). The step-up transformer 9 is provided to stably supply, for example, AC 220 V to the load 6 via the inverter 7 regardless of the voltage fluctuation of the system 8. The DC voltage to be input to the inverter 7 necessary for supplying AC 220 V to the load 6 is DC 310 V, which is √ (2) times AC 220 V. However, in consideration of the voltage drop due to a filter or the like, In the embodiment, a positive α voltage is added in advance, and the DC voltage applied from the rectifier 10 to the DC unit 37 is set to be DC 340V. Therefore, the voltage output by boosting the voltage from the system 8 by the step-up transformer 9 is set to AC220V which is 1 / √ (2) times DC340V.

  The circuit connected to the DC unit 37 from the system 8 through the step-up transformer 9 and the rectifier 10 is configured so that when the voltage Vdc of the DC unit 37 described above becomes equal to or less than DC340V, for example, defined as the first voltage value Vc1, The DC transformer 37 is configured to be fed through the step-up transformer 9 and the rectifier 10.

  The regenerative resistor 11 is provided so as to be connected to a regenerative command unit 47 provided in the inverter 7 connected to the lines 34 and 35. When the voltage Vdc of the direct current unit 37 becomes, for example, DC 400 V or more determined as the second voltage value Vc2, a regenerative command signal is given to the transistor 48 of the regenerative command unit 47, and the regenerative resistor 11 is energized by the operation of the transistor 48. Consume power. The operation of the transistor 48 is performed by inputting a set voltage DC400V as the second voltage value Vc2 and a voltage Vdc of the DC unit 37 detected by the voltage sensor 46 from a processing circuit which is a control means (not shown) to a subtracter (not shown). This is realized by inputting the output of the subtractor to the transistor 48.

  Hereinafter, the operation and control of the turbine generator 1 will be described. The start-up control of the turbine power generator 1 is performed according to a predetermined start-up sequence. At startup, the permanent magnet type synchronous generator 3 receives AC power supply from the system 8 via the converter 5, and starts rotating as the synchronous motor 3a. In the process of increasing the rotational speed of the synchronous motor 3a accompanying the increase in the frequency of the AC power supplied through the converter 5, fuel is supplied from the gas compressor 26 connected to the fuel source 24 to the combustor 23 and ignited.

  The fuel supply from the gas compressor 26 is performed as follows. The fuel supply amount is sent from the control means to the gas compressor controller 27 according to the start control map 52 stored in advance in the memory of the control means, that is, the data giving the relationship between the elapsed time at the time of start-up and the fuel supply amount. Is output as The gas compressor controller 27 stores the fuel supply amount in the gas compressor 26 as a rotational speed command signal in accordance with the fuel index 49 stored in the memory, that is, a map that gives the relationship between the fuel supply amount and the rotational speed of the turbine 21. Output. The gas compressor 26 supplies fuel from the fuel source 24 to the combustor 23 in response to the rotational speed command signal.

  Since the rotational speed of the turbine 21 set according to the startup sequence is larger than the rotational speed corresponding to the frequency of the AC power fed from the system 8, the converter 5 is supplied from the converter 8 to the permanent magnet synchronous generator 3. The current that has flowed in the reverse direction is reversed so as to flow out from the gas turbine 2, and thus the permanent magnet synchronous generator 3, toward the converter 5, and the turbine power generator 1 is started.

  The output voltage of the inverter 7 of the turbine power generator 1 during the operation is determined by the load 6 to be connected. The gas turbine 2 has a characteristic that the efficiency is higher when the gas turbine 2 is operated at a lower rotational speed than the rated rotational speed during operation at an output lower than the rated output. Therefore, in order to perform an operation with an emphasis on efficiency, it is necessary to change the rotation speed according to the output. The turbine power generator 1 is controlled so as to select an optimum rotational speed according to the output voltage of the inverter 7 determined by the load 6 by using the synchronizing force of the permanent magnet type synchronous generator 3.

  Selection control of the optimum rotational speed of the gas turbine 2 is performed as follows. First, a turbine speed setting map 50 that gives a relationship between a load and an appropriate turbine speed for the load is obtained in advance and stored in a memory. The control means outputs the turbine speed selected from the turbine speed setting map 50 according to the detection output from the load detection sensor 6a for detecting the load 6 to the converter 5 as a turbine speed command signal. Selection of the optimum rotational speed by constraining the rotational speed of the permanent magnet synchronous generator 3 to the rotational speed indicated by the turbine rotational speed command signal by the synchronizing force according to the frequency output from the converter 5 Is realized.

  Hereinafter, the synchronization force of the permanent magnet type synchronous generator 3 will be described. In the state where the permanent magnet type synchronous generator 3 is generating electric power, the phase of the induced voltage of the permanent magnet type synchronous generator 3 operates in a state where it is advanced with respect to the terminal voltage, and the difference between the induced voltage and the terminal voltage. Is divided by the impedance of the winding or the like of the permanent magnet type synchronous generator 3 and flows from the terminal of the permanent magnet type synchronous generator 3 toward the converter 5. Due to the interaction between the current and the magnetic field, a deceleration torque acts on the rotor 28 of the permanent magnet type synchronous generator 3, and if this deceleration torque and the power from the gas turbine 2 are balanced, the permanent magnet type synchronous generator. 3 continues power generation in a stable state.

  When the driving torque of the gas turbine 2 decreases in this state, the electrical deceleration torque becomes larger, the rotor 28 is decelerated, and the phase of the induced voltage of the permanent magnet synchronous generator 3 with respect to the voltage generated by the converter 5 Decrease. As a result, the current from the permanent magnet type synchronous generator 3 to the converter 5 is reduced, the torque for electromagnetically decelerating the rotor 28 is also reduced, and a new balanced state in which the generated power is reduced is reached.

  On the contrary, when the driving torque of the gas turbine 2 increases, the driving torque of the gas turbine 2 becomes larger than the electric deceleration torque, the rotor 28 is accelerated, and the generator voltage with respect to the voltage generated by the converter 5 is increased. The phase of the induced voltage increases. As a result, the current from the permanent magnet type synchronous generator 3 to the converter 5 increases, the deceleration torque acting on the rotor 28 electromagnetically increases, and a new balanced state in which the generated power increases is reached.

  Thus, acceleration torque or deceleration torque is electrically generated in the permanent magnet type synchronous generator 3 in accordance with the phase difference between the induced voltage and the terminal voltage defined by the converter 5. This is called a synchronizing force, and acts so as not to cause a deviation in the rotational speed of the permanent magnet type synchronous generator 3 with respect to the frequency of the voltage generated by the converter 5. That is, by increasing or decreasing the frequency of the generator terminal voltage set by the converter 5 with respect to a certain steady state, it is possible to increase or decrease the operating rotational speed of the gas turbine 2 to follow it.

  Furthermore, when the torque of the gas turbine 2 that drives the permanent magnet type synchronous generator 3 is small, the induced voltage of the permanent magnet type synchronous generator 3 has a phase relative to the terminal voltage of the permanent magnet type synchronous generator 3. In contrast to the time of power generation, the current flows from the terminal to the permanent magnet synchronous generator 3, and the permanent magnet synchronous generator 3 operates as the synchronous motor 3a and is electrically driven in the direction of accelerating the rotation. Torque is generated. Thus, it is possible to control the rotation continuously and seamlessly from the state where the permanent magnet type synchronous generator 3 is rotated as the synchronous motor 3a to the state where electric power is taken out from the permanent magnet type synchronous generator 3. This makes it possible to select and operate at the optimum rotational speed in the same output state.

  However, there is a limit to the synchronization force that causes the permanent magnet synchronous generator 3 to follow the frequency of the generator terminal voltage generated by the converter 5, and it becomes impossible to follow a rapid frequency change accompanying the fluctuation of the load 6. Further, if a large amount of electric power is taken out at a low power generation frequency, the driving torque of the gas turbine 2 acts exceeding the limit of the torque that can be electrically generated, and the rotational speed of the permanent magnet synchronous generator 3 is also the terminal voltage. It becomes impossible to follow the frequency. In order to prevent such a phenomenon, control of power conversion and control of the gas turbine 2 are performed by controlling the fuel within the range of power that can be generated at the rotation speed corresponding to the set terminal voltage and frequency. Must be connected.

  In the turbine power generator 1 of the present embodiment, the minimum signal selection circuit 51 is configured to control the output of the gas turbine based on the fuel flow rate during operation. Hereinafter, output control of the gas turbine 2 by the minimum signal selection circuit 51 will be described.

  The minimum signal selection circuit 51 selects the minimum (smaller) fuel flow rate among the fuel flow rates determined by the exhaust gas temperature control and the load control. The fuel flow rate determined by the exhaust gas temperature control is the data of the detected exhaust gas temperature EGT of the gas turbine 2 and the detected exhaust gas temperature EGT and the preset exhaust gas temperature data corresponding to the gas turbine rotational speed corresponding to the load 6. This is the fuel flow rate necessary for changing the rotational speed so that the deviation ΔT (= SEGT−EGT) from the set exhaust gas temperature SEGT obtained from a certain exhaust gas temperature setting map 53 becomes zero (0). The deviation ΔT is calculated by inputting the detected exhaust gas temperature EGT signal and the set exhaust gas temperature SEGT signal to the subtractor 54, and a control signal for setting the deviation ΔT to 0 is obtained by the PID control circuit 55. The gas turbine rotational speed corresponding to the load 6 is the gas turbine rotational speed obtained from the turbine speed setting map 50 described above, and the exhaust gas temperature setting map 53 is also stored in the memory in advance.

  The fuel flow rate determined by the load control is a detected voltage value for a predetermined voltage set value Vs (DC 360 V in the present embodiment) by detecting the voltage Vdc of the DC unit 37 output from the converter 5 to the inverter 7. This is the fuel flow rate necessary for changing the rotational speed so that the deviation ΔV (= Vs−Vdc) of Vdc becomes zero. The deviation ΔV is calculated by inputting the signal of the voltage setting value Vs and the signal of the detection voltage value Vdc to the subtractor 56, and a control signal for setting the deviation ΔV to 0 is obtained by the PID control circuit 57. The signal of the voltage set value Vs can be given as an instruction signal from the control means, for example.

  Strictly speaking, the minimum fuel flow rate signal selected by the minimum signal selection circuit 51 is an instruction signal for the gas turbine speed, but the instruction signal for the gas turbine speed is used as a fuel injection command signal for the gas compressor controller 27. Given that, the gas compressor controller 27 selects the fuel input command signal as the fuel flow rate to be supplied in correspondence with the fuel index 49, so the selection signal in the minimum signal selection circuit 51 is also expressed as the fuel flow rate for convenience.

  The fuel supply amount selected by the gas compressor controller 27 is given to the gas compressor 26 as a rotational speed command signal, and the gas compressor 26 supplies the fuel flow rate according to the rotational speed command signal to the combustor 23 to supply the gas turbine. The rotational speed of 21 is controlled.

  However, even with such fuel flow control, the rotational speed of the gas turbine 2, that is, the power generation output of the permanent magnet synchronous generator 3 cannot be immediately responded to a sudden change in the load 6, and the response speed Is not enough. Therefore, in the turbine power generator 1 of the present invention, even if the response of the permanent magnet type synchronous generator 3 to the fluctuation of the load 6 is not sufficient, the output from the inverter 7 is supplied by supplying power from the system 8 to the inverter 7. Enables high-speed control.

  For example, when the follow-up of the rotational speed control of the gas turbine 2 is delayed even though the load 6 is increased, the voltage Vdc of the direct current unit 37 is lower than the set voltage value Vs = DC360V by the load control. However, since the set voltage of the rectifier 10 connected to the system 8 is DC340V, when the voltage Vdc of the DC unit 37 detected by the voltage sensor 46 becomes equal to or lower than DC340V which is the first voltage value Vc1, the voltage is boosted from the system 8. Power is supplied to the DC unit 37 through the transformer 9 and the rectifier 10. Therefore, the DC voltage input to the inverter 7 does not fall below DC340V.

  On the other hand, when the follow-up of the rotational speed control of the gas turbine 2 is delayed even though the load 6 is reduced, the voltage Vdc of the direct current unit 37 is higher than the set voltage value Vs = DC360V by the load control. . However, when the voltage Vdc of the direct current unit 37 detected by the voltage sensor 46 becomes equal to or higher than DC400V which is the second voltage value Vc2 (this voltage value is set with reference to a withstand voltage such as the inverter 7), The transistor 48 is turned on to supply power to the regenerative resistor 11, and power is consumed by the regenerative resistor 11. As a result, the DC voltage input to the inverter 7 does not exceed DC 400V, which is the second voltage value Vc2.

  Thus, regardless of the output of the turbine generator 4, a DC voltage of DC 340 to 400 V is always input to the inverter 7. This enables high-speed control of the output response of the inverter 7 with respect to the fluctuation of the load 6. That is, in the turbine power generation device 1, for example, an output voltage / frequency instruction signal output from the output voltage / frequency setting means 60 provided in the control means and a detection signal from the inverter output sensor 61 that detects the output of the inverter 7. The PI control circuit 63 controls the deviation to be 0, which is input to the subtractor 62, and the calculation result by the subtractor 62, and the output of the inverter 7 is controlled by the control instruction signal. The circuit for controlling the output of the inverter 7 can be executed independently without depending on the output of the turbine generator 4 when a DC voltage of DC 340 to 400 V is always input to the inverter 7. , Extremely high speed control becomes possible.

  The turbine generator 1 receives power from the system 8 when the power generated by the turbine generator 4 is insufficient for an increase in the load 6, and the power generated by the turbine generator 4 is excessive for a decrease in the load 6. In some cases, surplus power is not consumed by the regenerative resistor 11 and returned to the system, so that a protection device for the system 8 is not required, and power storage for absorbing load fluctuations in an area where output control cannot follow. No elements are needed.

  FIG. 3 is a timing chart of output, power, and Vdc corresponding to load fluctuations. First, the fluctuation of the load 6 is shown. FIG. 3 illustrates a case where the load 6 increases at time t1, then changes at a constant value at times t1 to t2, and decreases at time t2.

  As described above, since the turbine generator 4 does not have sufficient responsiveness, its output cannot be increased rapidly in response to the sudden increase in the load 6 at time t1, and it only increases gradually from time t1 to time t11. Absent. Since the output of the turbine generator 4 cannot follow the increase in the load 8, the voltage Vdc of the DC unit 37 decreases. However, when the voltage Vdc of the DC unit 37 reaches the first voltage value Vc1, the DC unit 37 37, that is, power is supplied to the inverter 7, so that the voltage Vdc of the DC unit 37 does not drop below Vc1, and the output of the inverter 7 follows the increase of the load 6 with high responsiveness.

  When the output of the turbine generator 4 increases to an output that can respond to the increase in the load 6 over time from time t1 to time t11, the power supply from the system 8 gradually decreases from time t1 to time t11, The power supply is stopped at time t11. The voltage Vdc of the direct current unit 37 also returns to a predetermined voltage value at time t11 and becomes stable thereafter.

  When the load 6 suddenly decreases at the time t2, the turbine generator 4 cannot suddenly reduce the output in response to the sudden decrease of the load 6 at the time t2, but only gradually decreases from the time t2 to the time t22. Since the output of the turbine generator 4 cannot follow the decrease in the load 8, the voltage Vdc of the DC unit 37 increases, but when the voltage Vdc of the DC unit 37 reaches the second voltage value Vc2, the regenerative resistor 11 is energized. Therefore, the voltage Vdc of the DC unit 37 does not rise above Vc2 and the output of the inverter 7 follows the decrease of the load 6 with high responsiveness.

  When the output of the turbine generator 4 decreases to an output that can cope with the decrease of the load 6 over time from time t2 to time t22, the power consumption in the regenerative resistor 11 gradually decreases from time t2 to time t22. At time t22, energization to the regenerative resistor 11 is stopped. The voltage Vdc of the DC unit 37 also returns to a predetermined voltage value at time t22, and thereafter becomes stable.

  FIG. 4 is a system diagram showing a simplified configuration of a turbine power generator 70 according to the second embodiment of the present invention, and FIG. 5 is a diagram showing a circuit of a main part of the turbine power generator 70 shown in FIG. is there. The turbine power generation apparatus 70 of the present embodiment is similar to the turbine power generation apparatus 1 of the first embodiment, and corresponding portions are denoted by the same reference numerals and description thereof is omitted.

  The characteristic of the turbine power generator 70 is that a PWM converter 71 is used instead of the rectifier 10 of the turbine power generator 1 of the first embodiment. The PWM converter 71 of the present embodiment has the same basic configuration as the converter 5 connected to the turbine generator 4, converts AC power input from the system 8 into DC power, and outputs the DC power to the DC unit 37. By using the PWM converter 71 to supply power from the system 8 to the DC unit 37, voltage control can be performed with higher accuracy.

  Since the PWM converter 71 is configured to be capable of power conversion in both directions, it has a function of stabilizing power received from the system 8 and returning excess power to the system 8. Therefore, in the turbine power generation device 70, the PWM converter 71 is operated only for the direct current of the AC power received from the system 8 and the stabilization of the voltage, and the surplus power is not returned to the system 8. For the purpose, a command value limiter 72 is provided so that the current command value does not have a negative sign.

  The limiter 72 is given, for example, a result obtained by calculating the set voltage instruction signal from the DC voltage setting means 73 provided in the control means and the output voltage detection signal of the PWM converter 71 by the subtractor 74. The output signal from limiter 72 is applied to PI control circuit 75, and PI control circuit 75 outputs an operation instruction signal for PWM converter 71 in response to the output signal from limiter 72. The PWM converter 71 is controlled in accordance with the operation instruction signal from the PI control circuit 75 so as to operate only for the above-described direct current and voltage stabilization.

  In addition, although it becomes impossible to flow a negative current by providing the command value limiter 72, the voltage rise caused by the fact that the negative current cannot flow is caused by the power consumption in the resistor or the rotation speed of the gas turbine 2. The problem is solved by using the turbine power generation device 70 as an energy absorption device, such as increasing the command.

  The turbine power generation device 70 of the present embodiment can achieve the same effects as the turbine power generation device 1 of the first embodiment, and is the first reference voltage value for starting power supply from the system 8 to the DC unit 37. By setting the voltage value Vc1 to the same DC 360V as the set voltage value Vs for load control, it becomes possible to share the load of power feeding between the turbine generator 4 and the system 8.

1 is a system diagram showing a simplified configuration of a turbine power generator 1 according to an embodiment of the present invention. It is a figure which shows the circuit of the principal part of the turbine generator 1 shown in FIG. It is a timing chart of the output corresponding to the fluctuation | variation of load, electric power, and Vdc. It is a systematic diagram which simplifies and shows the structure of the turbine power generator 70 which is the 2nd Embodiment of this invention. It is a figure which shows the circuit of the principal part of the turbine generator set 70 shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,70 Turbine power generator 2 Gas turbine 3 Permanent magnet type synchronous generator 4 Turbine generator 5 Converter 6 Load 7 Inverter 8 AC connection system 9 Step-up transformer 10 Rectifier 11 Regenerative resistance 21 Turbine 22 Air compressor 23 Combustor 24 Fuel Source 25 Shutoff valve 26 Gas compressor 27 Gas compressor controller 71 PWM converter 72 Limiter

Claims (4)

(A) a turbine generator in which a permanent magnet synchronous generator is connected to a gas turbine whose output can be controlled by a fuel flow rate;
(B) a converter connected to the turbine generator;
(C) an inverter connected between the converter and the load;
(D) transforming means connected to the AC interconnection system;
(E) rectifying means connected between the transformer means and the inverter;
(F) including a regenerative resistor connected to a direct current part that is an output part from the converter,
(G) In a state where the voltage fed from the turbine generator to the inverter via the converter is equal to or lower than the first voltage value determined in advance, the inverter is fed from the AC interconnection system via the transformer means and the rectifier means,
(H) A turbine power generator configured to consume surplus power by a regenerative resistor when a voltage fed from a turbine generator to an inverter via a converter is equal to or higher than a predetermined second voltage value. apparatus. (A) a turbine generator in which a permanent magnet synchronous generator is connected to a gas turbine whose output can be controlled by a fuel flow rate;
(B) a converter connected to the turbine generator;
(C) an inverter connected between the converter and the load;
(D) a PWM converter connected between the AC interconnection system and the inverter;
(E) a limiter that is connected to the PWM converter and limits the output direction of the PWM converter to a direction from the AC interconnection system to the inverter;
(F) including a regenerative resistor connected to a direct current part that is an output part from the converter,
(G) In a state where the voltage supplied from the turbine generator to the inverter via the converter is equal to or lower than the first voltage value determined in advance, the inverter is supplied from the AC interconnection system via the PWM converter,
(H) Turbine power generation configured to consume surplus power by regenerative resistance in a state where the voltage fed from the turbine generator through the converter to the inverter is equal to or higher than a predetermined second voltage value apparatus. A permanent magnet type synchronous generator connected to a gas turbine whose output can be controlled by the fuel flow rate is driven to generate power, the generated power is converted to DC power by a converter, and the DC power output from the converter is further converted to AC by an inverter. In the self-sustaining operation method of the turbine power generator that converts power into electric power and supplies the load,
When the voltage supplied to the inverter through the converter from the turbine generator in which the permanent magnet type synchronous generator is connected to the gas turbine is equal to or lower than a predetermined first voltage value, the inverter is supplied from the AC interconnection system, When the voltage supplied to the inverter from the turbine generator through the converter is equal to or higher than a predetermined second voltage value, by consuming excess power with the regenerative resistor,
A self-sustaining operation method for a turbine generator, wherein the voltage input to the inverter is controlled to be in a range exceeding the first voltage value and less than the second voltage value. The output control of the gas turbine by the fuel flow rate is
At startup,
Based on a predetermined relationship between the fuel flow rate and the rotational speed of the gas turbine, the fuel flow rate is charged so that the gas turbine has a predetermined rotational speed.
When driving after startup,
The exhaust gas temperature EGT of the gas turbine is detected, the gas turbine rotation speed determined in advance corresponding to the magnitude of the load, the set exhaust gas temperature SEGT predetermined to correspond to the gas turbine rotation speed, and the detected exhaust gas temperature EGT The fuel flow rate necessary for changing the rotational speed so that the deviation ΔT (= SEGT−EGT) of
DC voltage Vdc output from the converter to the inverter is detected, and the rotational speed is changed so that the deviation ΔV (= Vs−Vdc) of the detected voltage value Vdc with respect to the predetermined voltage setting value Vs becomes zero. Of the fuel flow required for
The self-sustained operation method for a turbine power generator according to claim 3, wherein the self-sustained operation method is performed by selecting a smaller fuel flow rate.

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