JPH0783075A - Control device of generator - Google Patents

Abstract

PURPOSE:To stably supply electric power while reducing fuel consumption. CONSTITUTION:This control device of a generator is furnished with a generator 42 driven by an engine 41, an inverter 43 to deliver output from the generator 42 to a load 44, a means 45 to detect the load 44, a means 46 to detect engine speed, a mean 47 to carry out feedback control of a fuel injection quantity so as to provide the target engine speed in accordance with the load 44, a means 48 to detect output voltage of the generator 42 and a means 49 to compute a correction amount of the target engine speed from the engine speed and the output voltage detected in a driving condition where the output from the generator 42 to the load 44 is cut out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a generator control device.

[0002]

2. Description of the Related Art In a device in which a generator is directly connected to a gas turbine engine, there is a demand for operation at a rotational speed as low as possible with respect to a load in order to reduce fuel consumption.

The current generated by the generator is converted into a direct current in the inverter, and chopped while monitoring the inverter output voltage with a transistor to form a sine wave having a constant output voltage and frequency (Japanese Patent Laid-Open No. 59-222099).
Gazette, reference).

[0004]

However, in such a conventional generator control device, the output voltage of the permanent magnet magnetic excitation type generator is the inlet voltage of the inverter due to the initial variation of the magnetic force and the deterioration over time. May run out.

If the magnetic force is increased in order to avoid this, when the rotational speed is increased under high load, the voltage may become too high and the efficiency and durability of the inverter may deteriorate.

Further, the gas turbine engine can be operated at a lower turbine inlet temperature as the engine performance is higher under the same load and the same rotation speed to obtain the same output.
If the engine speed is set low when the turbine inlet temperature is high and engine performance is low, the rate of decrease in the air amount is greater than the rate of decrease in the fuel injection amount supplied to the combustor. As a result, the temperature rises and the turbine inlet temperature rises, leading to poor fuel economy.

In view of the above problems, the present invention aims to reduce fuel consumption and supply stable electric power in a generator control device.

[0008]

According to a first aspect of the present invention, there is provided a control device for a generator which, as shown in FIG. 1, sends a generator 42 driven by an engine 41 and an output from the generator 42 to a load 44. Inverter 43 and means 45 for detecting load
A means 46 for detecting the engine speed, a means 47 for performing feedback control of the fuel injection amount so as to obtain a target engine speed according to the load, a means 48 for detecting the output voltage of the generator 42, and a power generator. It is provided with a means 49 for calculating a correction amount of the target engine speed from the engine speed detected in the operating state in which the output from the machine 42 to the load 44 is cut off and the output voltage.

According to a second aspect of the present invention, there is provided a generator control device as shown in
As shown in, the generator 42 driven by the gas turbine engine 50 and the output from the generator 42 are connected to the load 44.
An inverter 43 for sending to, a means 45 for detecting a load,
A means 46 for detecting the engine speed, a means 47 for performing feedback control of the fuel injection amount so as to obtain a target engine speed according to the load, and a gas turbine engine 50.
51 for detecting the turbine inlet temperature of the generator, and the generator 42
From the engine to the load 44 is cut off, the means 52 for calculating the correction amount of the target engine speed from the engine speed detected in the operating state and the turbine inlet temperature.

[0010]

According to the first aspect of the present invention, the generator control device corrects the target engine speed from the engine speed and the output voltage detected in the no-load operation state. It is possible to prevent the voltage generated in the generator 42 from becoming insufficient or excessive. As a result, it is not necessary to increase the magnetic force of the permanent magnet more than necessary,
It is possible to prevent the output voltage from becoming too high and the efficiency and durability of the inverter 43 from being deteriorated when the engine speed is increased when the load is high.

According to the second aspect of the present invention, the control apparatus for the gas turbine generator corrects the target engine speed from the engine speed and the turbine inlet temperature detected in the no-load operating state, so that the turbine inlet temperature is high and the engine performance is high. By lowering the engine speed in a low state, it is possible to prevent the combustion temperature from rising excessively and suppress the fuel consumption rate.
In order to obtain the same output, the gas turbine engine can be operated at a lower turbine inlet temperature as the engine performance is higher at the same load and the same rotation speed.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 2, the gas turbine engine 1 has a compressor 2 that draws in atmospheric air and compresses it to a required pressure, and burns fuel inside to heat compressed air sent from the compressor 2 to heat it to a high temperature. The combustor 3 that produces gas, the turbine 4 that converts the energy of the combustion gas emitted from the combustor 3 into mechanical work, and the heat of the exhaust gas discharged from the turbine 4 sends it from the compressor 2 to the combustor 3. And a heat exchanger 5 for heating the compressed air.

A fuel adjusting valve 6 is provided to adjust the amount of fuel supplied to the combustor 3. The fuel injection amount from the fuel adjusting valve 6 is controlled by a command from the controller 7.

A generator 21 is directly connected to the turbine shaft 8 of the gas turbine engine 1. The generator 21 is a magnetic excitation type using a permanent magnet.

As shown in the electric circuit diagram of FIG. 3, the output from the three-phase AC generator 21 is converted into a single-phase 100V AC output by the transistor inverter 22 built in the controller 7, and the smoothing circuit outputs the 100V output. An electric load 28 is connected via 27. With the inverter 22,
An output having a constant voltage and a constant frequency is taken out regardless of the rotation speed of the generator 21.

The transistor inverter 22 is of a voltage type, and is composed of a half-wave rectifier circuit 23, an H-shaped bridge 24, and a large-capacity capacitor 25 that connects them. The half-wave rectifier circuit 23 includes six diodes 23a to 23f, and the H-type bridge 24 includes four transistors 24a.
.About.24d and four diodes 24e to 24h. After converting the three-phase alternating current from the generator 21 into a direct current by the rectifier circuit 23, the base currents of the four transistors 24a to 24d are turned on and off in a predetermined order to obtain a single-phase 100V sine wave output. To be

Transistors 26a to 26f are provided in parallel with the diodes 23a to 23f of the rectifier circuit 23 in order to operate or cut off the inverter 22, and all of the transistors 26a to 26f are turned off by a command from the controller 7. The rectifier circuit 23 works when
When a base current flows through the transistors 26a to 26f,
All the transistors 26a to 26f are turned on, the diodes 23a to 23f do not function, and the inverter 22
Is cut off.

The controller 7 comprising a microcomputer comprises a sensor 18 for detecting the rotational speed NCT of the turbine shaft 8, a sensor 17 for detecting the inlet temperature of the combustion gas entering the turbine 4,
Each detection signal of the sensor 16 that detects the inlet temperature of the intake air entering the condenser 2 is input, and the inverter 22 is operated and the operation of the gas turbine engine 1 is controlled.

The flowchart of FIG. 5 shows a control program executed by the controller 7 at the time of starting the gas turbine engine 1.

In step 1, after the gas turbine engine 1 is started, the fuel supply amount is increased to accelerate it.

In step 2, the detected engine speed NCT and the target idle speed NCT1 (for example, 8
50,000 rpm) and accelerate until the standard target idle speed NCT1 is reached.

When the engine speed reaches the standard target idle speed NCT1, the routine proceeds to step 3, where the intake air temperature T1 is reached.
, The output voltage VAC1 of the generator 21, and the detected values of the turbine inlet temperature T7 are read. These measurements are
The operation is performed in the no-load operation state before the start of power generation in which the power supply to the load 28 is cut off by the inverter 22.

In step 4, the second target idle speed NCTREF2 obtained by correcting the standard target idle speed NCT1 is obtained from the detected intake air temperature T1 by referring to T1MAP shown in FIG.

The output of the gas turbine engine 1 decreases as the intake air temperature T1 rises. Therefore, as shown in FIG. 6, the output is corrected by controlling the idle speed to be inversely proportional to the intake air temperature T1. It is possible to prevent the operation of the turbine engine 1 from stopping.

Next, in order to prevent the output voltage VAC1 from fluctuating due to variations in the magnetic force of the permanent magnets provided in the generator 21, the engine speed NCT detected in the operating state before the start of power generation is executed by the following routine. And output voltage VAC1
The target idle speed is corrected based on the detected value of.

In step 5, the detected output voltage VAC1 is compared with the standard voltage VST (for example, 100V) to determine whether the output voltage is excessive or insufficient.

The detected output voltage VAC1 is the standard voltage V
If it is lower than ST, proceed to step 6 and output voltage VA
Based on C1, the increase range NCTLOW of the engine speed is obtained by referring to N.MAP shown in FIG. Subsequently, the routine proceeds to step 7, where the third target idle speed NCTREF3 is calculated by adding the obtained increase amount NCTLOW to the second target idle speed NCTREF2.

On the other hand, when the detected output voltage VAC1 is higher than the standard voltage VST, the process proceeds to step 8 and the engine speed reduction range NCTOFST is obtained based on the output voltage VAC1 by referring to N.MAP shown in FIG. . Then, proceed to step 8 to set the second target idle speed NCTR.
A third target idle speed NCTREF3 is calculated by subtracting the increase range NCTOFST obtained for EF2.

The N.MAP shown in FIG. 8 is the voltage VAC1 generated in the main winding 21a of the generator 21 when the gas turbine engine 1 is operating at 80,000 rpm.
If the generated voltage VAC1 is lower than the standard voltage VST, the idle speed is increased according to the deviation with respect to the standard voltage VST, and if the generated voltage VAC1 is higher than the standard voltage VST, the idle speed is increased according to the deviation with respect to the standard voltage VST. It is set to lower.

As a result, the voltage VAC generated in the main winding 21a due to the initial variation in the magnetic force of the permanent magnet and the deterioration over time.
It is possible to avoid running out of 1 or excess. As a result, it is not necessary to increase the magnetic force of the permanent magnet more than necessary, and when the engine speed is increased under high load,
It can be prevented that the output voltage VAC1 becomes too high and the efficiency and durability of the inverter 22 deteriorate.

Next, in order to suppress the fuel consumption rate in response to the variation in the performance of the gas turbine engine 1, the engine speed NCT and the turbine inlet temperature T7 detected in the operating state before the start of power generation are detected by the following routine. The target idle speed is corrected based on the value.

In step 10, a correction value T7OFST of the engine speed is obtained by referring to N · T7MAP shown in FIG. 8 based on the turbine inlet temperature T7. Then, the process proceeds to step 11, where the third target idle speed NCTRE
The fourth target idle speed NCTREF4 is calculated by adding the correction value T7OFST obtained to F3, and the step 1
In step 2 or step 13, the calculated fourth target idle speed NCTREF4 and the calculated third target idle speed NCTREF3 are compared so as not to fall below the lower limit speed.

In the N.T7MAP shown in FIG. 8, when the gas turbine engine 1 is operated at 80,000 rpm, the turbine inlet temperature T7 is a standard temperature (for example, 600).
If the turbine inlet temperature T7 is higher than the standard temperature, the idle speed is increased according to the deviation from the standard temperature, and if the turbine inlet temperature T7 is higher than the standard temperature, the idle speed is increased.

Thus, in the state where the turbine inlet temperature T7 is high and the engine performance is low, it is possible to avoid setting the engine speed low and to prevent the combustion temperature from rising excessively simply because the generated voltage VAC1 is high. Can be prevented
The fuel consumption rate can be suppressed. The gas turbine engine 1
In order to obtain the same output, the higher the engine performance is, the lower the turbine inlet temperature T7 can be operated at the same load and the same rotation speed.

In steps 14 and 15, the fuel injection amount is controlled so that the engine speed NCT matches the fourth target idle speed NCTREF4.

In step 16, the inverter 22 is activated and the output to the load 28 is started.

Next, the flowchart of FIG. 9 shows a control program executed by the controller 7 during normal operation.

To explain this, in step 1, the current LOAD1 sent to the load 28 is read and the magnitude of the load is measured.

In step 2, the load current LOAD1
From the above, referring to N.LMAP in FIG. 10, the increase in engine speed NCTUP is obtained.

The increase NCTUP of the engine speed thus obtained controls the engine speed with a margin so that the gas turbine engine 1 can operate normally even if a load up to the upper limit of the current load is applied. And is a rotational speed determined by the load bearing capacity of the gas turbine engine 1 and the turbine inlet temperature T7.

In step 3, a fifth target idle speed NCTREF5 is calculated by adding the obtained increase amount NCTUP to the fourth target idle speed NCTREF4.

In step 4, the engine speed NC
The fuel injection amount is controlled so that T matches the fifth target idle speed NCTREF5.

[0044]

As described above, the present invention provides claim 1.
The control device of the generator described is configured to correct the target engine speed from the engine speed and output voltage detected in the no-load operation state, so the generator may be generated due to the initial variation in the magnetic force of the permanent magnet and deterioration over time. It is possible to avoid a shortage or an excessive voltage to be applied. As a result, it is not necessary to increase the magnetic force of the permanent magnets more than necessary, and it is possible to prevent the output voltage from becoming too high when the engine speed is increased under high load, and the efficiency and durability of the inverter from deteriorating. it can.

Since the control device for the gas turbine generator according to claim 2 is configured to correct the target engine speed from the engine speed and the turbine inlet temperature detected in the no-load operation state, the turbine inlet temperature is high. Prevents the combustion temperature from rising excessively when performance is low,
The fuel efficiency can be reduced and the durability of the gas turbine engine can be improved.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to claims of the invention according to claim 1.

FIG. 2 is a diagram corresponding to claims of the invention according to claim 2;

FIG. 3 is a configuration diagram of a power generator showing an embodiment of the present invention.

FIG. 4 is an electric circuit diagram of the same.

FIG. 5 is a flowchart for explaining control at the time of starting the same.

FIG. 6 is a characteristic diagram showing a map of target idle speed with respect to intake air temperature.

FIG. 7 is a characteristic diagram similarly showing a map of a correction value of a target idle speed with respect to a generated voltage.

FIG. 8 is a characteristic diagram similarly showing a map of a correction value of a target idle speed with respect to a turbine inlet temperature.

FIG. 9 is a flow chart for explaining control during normal operation as well.

FIG. 10 is a characteristic diagram similarly showing a map of a correction value of a target engine speed with respect to a load.

[Explanation of symbols]

 1 Gas Turbine Engine 2 Compressor 3 Combustor 4 Turbine 5 Heat Exchanger 6 Fuel Regulator 7 Controller 21 Generator 22 Inverter 28 Load 41 Engine 42 Generator 43 Inverter 44 Electric Load 45 Load Detecting Means 46 Revolution Detecting Means 47 Revolutions Control means 48 Output voltage detection means 49 Correction value calculation means 50 Gas turbine engine 51 Turbine inlet temperature detection means 52 Correction value calculation means

Claims (2)

[Claims] 1. A generator driven by an engine,
An inverter for sending the output from the generator to the load, a means for detecting the load, a means for detecting the engine speed, and a means for performing feedback control of the fuel injection amount so as to obtain a target engine speed according to the load. A means for detecting the output voltage of the generator, and means for calculating a correction amount of the target engine speed from the engine speed and the output voltage detected in the operating state in which the output from the generator to the load is cut off. A generator control device characterized by the above. 2. A generator driven by a gas turbine engine, an inverter for sending the output from the generator to a load, a means for detecting the load, a means for detecting the engine speed, and a target engine according to the load. Means for performing feedback control of the fuel injection amount so that the rotation speed is achieved, means for detecting the turbine inlet temperature of the gas turbine engine,
A generator control device comprising: a unit for calculating a correction amount of a target engine speed from an engine speed detected in an operating state in which the output from the generator to the load is cut off and a turbine inlet temperature. .