JPS6277098A - Gas turbine generator - Google Patents

Abstract

PURPOSE:To hold a generating output of a frequency constant by converting a high frequency power obtained by directly coupling a gas turbine engine and a high frequency generator to an AC power of desired frequency by an inverter. CONSTITUTION:A high frequency generator 44 is coupled directly with a gas turbine engine 42, the output of the generator 44 is rectified by a rectifier, converted by an inverter 50 to the desired AC frequency, and output. A field controller 70 controls the field current of the generator 44 in response to the generated output of the generator 44. A fuel supply controller 60 controls fuel supply to a combustor so that the speed of the engine 40 becomes constant.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a gas turbine generator, particularly a high-frequency generator that is rotated by a high-speed gas turbine, and the resulting high-frequency power output is converted into DC power. The present invention relates to an improvement of a gas turbine power generation device that uses an inverter to convert AC power into desired AC power.

[Prior Art] Various types of generators are useful as temporary power sources in remote areas where commercial frequency power sources are not easily available, outdoors, in mountainous areas, etc., and as emergency power sources in the event of a power outage. For example, devices that drive a generator using a reciprocating engine such as a gasoline engine or a diesel engine, or devices that drive a generator using a gas turbine engine have been put into practical use.

In the case of such conventional generators driven by engines, there is a problem in that the frequency of the generated output depends on the rotational speed of the generator, and this is especially true for various electrical equipment made to be compatible with commercial frequency power sources. For operation, controlling the generator output to the normal commercial frequency is an important issue.

When the above-mentioned reciprocating engine is used as a drive source, it is relatively easy to obtain a commercial frequency, and as shown in FIG. A generator 12 is directly connected to the reciprocating engine 10, and a sono output terminal 14 can provide a rotational output of several 1100 orps.
Almost stable commercial frequency three-phase output can be obtained for U, 14V, and 14W.

However, when a gas turbine engine is used as the driving source for a generator, as is well known, such a gas turbine engine rotates efficiently when rotating at high speed, so the output of the generator itself does not exceed the normal commercial frequency. The problem was that the output was extremely high in frequency.

Therefore, in conventional power generation devices using gas turbine engines, a reduction gear is incorporated into the gas turbine engine that rotates at 10,000 to 100,000 rpm to reduce the rotational speed of the generator to several 1100 rpm. There is.

Figure 5 shows a conventional single-shaft cast turbine engine 1.
6 is shown to rotate the generator 12.

The gas turbine engine 16 includes a turbine 20 and a compressor 22, which are themselves directly coupled at a main shaft 18.
As is well known, the intake air compressed by the compressor 22 receives fuel supply G in the combustor 24, and this combustion gas rotates the turbine 20 and is exhausted. Therefore, this main shaft 1
8 rotates at high speed, and after decelerating it with reduction gears 26 and 28, the generator 12 is rotated.

Therefore, from the outputs 14U, 14V, and 14 to 1 of the generator 12, it is possible to obtain a decelerated output of approximately the required frequency.

FIG. 6 shows a power generation device using a conventional gas turbine engine, and a two-shaft gas turbine 28 is used.

According to this two-shaft type cast turbine engine 2B, the compressor 22 is driven by a compressor turbine 30, and the combustion gas leaving the compressor turbine 30 rotates the power turbine 32 downstream, and is transmitted from its shaft 34 via a reducer. (power generation) Rotationally drive the number 12. This 2
Even in a power generation device using a shaft-type gas turbine, it is impossible to obtain the desired frequency power unless a speed reducer is used.

Such a speed reducer significantly reduces power generation efficiency, and also has various problems such as wear and noise generation of the speed reducer itself, which significantly reduces its usefulness as a power generation device.

In addition, a generator that rotates at several 1100 orps has a problem in that its volume and weight are larger than that of a high-frequency generator.

Generally, the generator output P is expressed as P=kD2LN, where k: constant, D: generator rotor diameter, L
: Generator rotor length, and N: Generator rotation speed.

Therefore, when suppressing the rotation speed N to below several 11,000 ro, in order to increase the desired output P by 1, it is necessary to use a generator with a large D2L, that is, a large and heavy motherboard.
There was a problem that it was not possible to obtain a small and portable power generation device.

In order to solve these various conventional problems, a high-speed turbine power generator disclosed in Japanese Patent Application Laid-Open No. 54-'11421 has been proposed as an improved device.

This device is characterized by directly connecting a high-speed turbine to a generator, converting the high-frequency power into direct current using a rectifier, and then converting this direct current back to commercial frequency using an inverter. This has the advantage that the gas turbine can be directly connected to the generator without using any equipment, and the generator itself can be grown as a small device.

[Problems to be Solved by the Invention] However, even with the conventional device mentioned above, when the generator output changes rapidly depending on the load requirements, the output frequency fluctuates and a stable frequency cannot be obtained. There was a problem.

FIG. 7 shows the power generation characteristics of the conventional device.

In FIG. 7, time ↑, t2 indicates a state where the load increases rapidly and an increase in engine output is required, and time t
3 indicates a state in which the required amount of load has suddenly decreased.

The gas turbine engine itself has a fuel control device that increases engine output in response to an increase in load, or this increase is accompanied by a time delay and cannot immediately follow sudden changes in load.

Therefore, the engine speed decreases (1
1, 12>or rises (t3). Therefore, it is understood that this variation in the engine speed immediately causes a variation in the generator output in the conventional blood-sperm type power generator.

In other words, in the conventional device, the power generation output was controlled by adjusting the rotation speed by controlling the fuel supply of the gas turbine engine, so in reality, there was a delay in the engine rotation speed in response to sudden changes in load. When this delay occurs, a problem arises in that the power generation output itself decreases or increases.

The present invention was made in view of the above-mentioned conventional problems, and its purpose is to be able to obtain stable power generation output even when the load fluctuates rapidly, and to be able to use it as a small and lightweight power generation device. Our objective is to provide a cast turbine power generation system that can perform the following functions.

[Means for Solving the Problems] In order to achieve the above object, the present invention first rectifies the high frequency power obtained by directly connecting a gas turbine engine and a high frequency generator into direct current, and then converts this into an inverter. In addition, the gas turbine engine itself uses fuel control to maintain a constant rotational speed, and the reduction in engine output that occurs when the load fluctuates is controlled by the field control of the generator itself. This feature compensates for the drop in generator output power, and the combination of both controls always keeps the power generation output and frequency constant.

[Example] Preferred embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a preferred embodiment of the invention.

In the figure, the gas turbine engine 40 is the fifth engine mentioned above.
．． It can be configured as either a single-shaft gas turbine or a two-shaft gas turbine as shown in FIG. 6, and its main shaft 42 rotates at high speed.
In the embodiment, the rotation speed of the main shaft 40 is 8B, OOO
It is set to rpm.

In the present invention, a high frequency generator 44 is directly connected to the gas turbine engine 42, and as a result, the high frequency generator 44, which operates at, for example, 86,000 rpm, is faster than the conventional device which rotates at several 11,000 rD. In order to obtain the same output, it is possible to form a device that is significantly smaller and lighter than the conventional type, and in the embodiment, its volume and weight are reduced to about 1720 mm compared to the conventional type.

Therefore, in the present invention, it is possible to obtain a small and portable power generation device by combining the cast turbine engine 40 and the high frequency power generator 44.

The high frequency generator 44 in FIG. 1 consists of two machines, and when driven to rotate at the aforementioned 86.00 rpm, 1.
Outputs high frequency power of 433Hz.

The high-frequency power of the power generation UI 44 is thus significantly higher in frequency than the normal commercial frequency, and cannot normally be used as is. Therefore, in the present invention, this is first converted into a DC signal, and then the desired frequency is converted using an inverter. It consists of a configuration that performs the following and calculates the necessary AC frequency by 1q.

The DC conversion is performed by a rectifier 46 and a smoothing capacitor 48 in the figure, and this DC output is further inversely converted via an inverter 50 to output terminals 52U, 52V,
52W is output as power with commercial frequency.

The frequency conversion of the inverter 50 is performed by a frequency control circuit 54.
and a reference signal generation circuit 56.

FIG. 2 shows a specific circuit configuration for the rectification and frequency conversion, in which the rectifier 46 consists of a full-wave rectification circuit;
Further, the inverter 50 is composed of an inverter circuit using 1 to RANCISTORs.

That is, the high frequency 3 of the high frequency generator 44 shown in FIG.
The phase outputs 44U, 4.4V, 44W are the diodes 46a, 46b, 46c, 46d, 46e, 46f of the rectifier 46.
is full-wave rectified and converted to DC power.

This DC power is smoothed by the capacitor 48, and the surge voltage is absorbed.

Next, this DC power is converted into a desired three-phase AC power by an inverter 50, and in the embodiment, this inverter 50 includes transistors 50aU, 50aV, 50aW, 50bU, 5
0bV, 50bW and each of these transistors 5Qa, 50
Diode 50cU, 50cV, 5 connected in parallel to b
0 cW, 50 dU, 50 dV, 50 dW, and each base terminal 50e, 5Of of each transistor 50a, 50b.
.

Switching is controlled by signals supplied to 5oc+, 5oh, 5oi, and 5oj, and the input DC power is outputted to the terminal 52 as desired commercial power of, for example, 50H2. Each base terminal 506 of the transistor
The control signal supplied to 50j is controlled by the frequency control circuit 54 described above, and the control circuit 54 outputs the outputs e to j of the transistors at a predetermined timing based on the output signal provided from the reference signal generation circuit 56. The signal is supplied to each base terminal 50e to 50j, and a desired frequency conversion effect is performed by switching these.

Therefore, according to the power generating apparatus according to the present invention, its output power frequency is controlled only by the signal from the control circuit 54, and a stable output frequency can always be obtained.

In the embodiments described above, the inverter 50 uses transistors for the switching action, but it is also possible to use SIRIS or GTO instead of transistors.

What is characteristic about the present invention is that in addition to the above-mentioned small-sized device that directly connects the gas turbine engine 40 and the high-frequency generator 44, the gas turbine engine 40 is equipped with fuel control to keep its rotational speed constant. It is also characterized in that the high frequency generator 44 is subjected to field control in accordance with fluctuations in the generator output.

A fuel supply control circuit 60 is provided to control the fuel of the gas turbine engine 40, and the amount of fuel supplied from the fuel tank 62 to the combustor of the gas turbine engine 40 by the fuel pump 64 is adjusted by controlling the fuel valve 66. be done. Further, a rotation speed detection signal Rv is supplied from the gas turbine engine 40 to the fuel supply control circuit 60, thereby controlling the fuel supply to the combustor so that the rotation of the main shaft 42 of the gas turbine 40 is always constant. Engine output is stabilized.

In the embodiment, the supply amount is controlled by controlling the fuel valve 66, but in the present invention, it is also possible to remove such a fuel valve and adjust the pressure of the fuel pump 64 by the fuel supply control circuit 60. It is.

On the other hand, field control of the high-frequency generator 44, which is a feature of the present invention, is performed by a field control circuit 70, and the DC conversion output VD of the generator 44, which is the output of the smoothing capacitor 48, is performed by a field control circuit 70.
C is detected, and the high frequency generator 4 is activated according to this DC output voltage.
The field current supplied to the No. 4 field coil 72 is controlled.

Therefore, according to the present invention, the field current is adjusted by quickly detecting fluctuations in the generator output, increasing the field current when the output voltage decreases, and decreasing the field current when the output voltage increases. It is possible to always obtain constant power generation output.

FIG. 3 shows the power generating device output stabilizing effect of this embodiment.

In FIG. 3, the required load changes rapidly as tl, ↑2°t3.

Due to such load fluctuations, the gas turbine engine 40
The rotation of its main N42 decreases (tl.

) or rise (t3), the fuel supply control circuit 60 listens to (closes) the fuel valve 66 and increases (decreases) the engine output, but in reality, there is always a control delay in this fuel supply control. As a result, the engine output is unable to follow the load fluctuations, resulting in a transient under-output (over-output) as shown in the figure, and the engine speed itself of the main shaft 42 also temporarily decreases. (rise) to cause a phenomenon.

However, in the present invention, when there is such a sudden change in load, the output of the generator 44 or the DC output V in the embodiment. 0, the field control circuit 70 quickly changes the field current supplied to the field coil 72 as shown in the figure, and adjusts the power generation action of the generator 44 to compensate for the transient gas turbine output fluctuation. do.

That is, at time t1. At time t2, the field current temporarily increases to increase the generator output, and similarly at time t3, the field current is temporarily lowered to rapidly decrease the generator output.

Therefore, according to the present invention, it is possible to control the power generation output quickly and without delay in accordance with the load.

In this embodiment, desired signals are exchanged between the field control circuit 70 and the fuel supply 'a circuit 60, and when the gas turbine engine 40 is started, the field current is kept constant until a constant rotational speed is reached. Even if the supply is cut off or the fuel runs out, field current cutoff control is performed.
The field control circuit 70 supplies signals such as cutting off fuel supply when the field control signal shows an abnormal value, and concrete control between the two control circuits is performed.

The gas turbine power generation system shown in FIG. 1 is further provided with a fetal movement device for the gas turbine engine 40 and other auxiliary equipment.

That is, in the embodiment, the above-described high-frequency generator 44 is used as a starting motor to start the engine 40, and an exciting current is supplied from the rotary inverter 80 to the generator 44, thereby causing the generator 44 to function as a starting motor. The desired starting action is performed by rotating the engine 40.

Contacts 84 are connected to the rotary inverter 80 from the battery 82 .
DC power is supplied through the rotary inverter 80.
converts this DC power into three-phase AC power and connects contacts 86 and 8.
81 to the armature coil of the high frequency generator 44.

Therefore, when each contact 84-88 is closed,
The generator 44 operates as an electric motor and can initially start the engine 40. Of course, during this fetal movement, the operation of the inverter 5o is stopped, and the power generation action is stopped until the engine 40 reaches a predetermined high speed rotation range.

In this embodiment, the device is provided with the auxiliary equipment 92 described above, and these auxiliary equipment 92 consists of an oil pump, a fan, a relay, etc., and is driven by DC power from the battery 82 to control the rotation of the gas turbine engine 40. Can maintain proper action.

As described above, according to the present invention, by directly connecting a high-speed rotating gas turbine engine to a high-frequency generator, it is possible to generate a sufficiently large generator output of 1 q even though the generator itself is small. It becomes possible to construct a portable engine power generation device.

The high-frequency power is once converted to DC and then converted to AC at a desired frequency by an inverter, and can be used in various fields of application as a normal commercial power source, for example.

As mentioned above, since the output of the generator is at a high frequency, there is little ripple in the rectified output, and as a result, a smoothing capacitor with a small capacity can sufficiently perform its function, and the entire device can be constructed in one piece. Even in some cases, it is possible to make the device extremely compact and lightweight.

In the present invention, the gas turbine engine output of such a power generation device is controlled according to the load by fuel supply control, and in order to further compensate for the delay at this time by field control of the high frequency generator, the generator output is controlled. It becomes possible to properly adapt to load fluctuations, and extremely stable power generation is possible without causing any shortage of output.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a portable gas turbine power generation device that is small and lightweight, and has stable output and frequency.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram showing a preferred embodiment of the gas turbine power generation device according to the present invention, Fig. 2 is a specific circuit diagram of the rectifying inverter device in Fig. 1, and Fig. 3 is an output stabilization diagram according to the present invention. Figure 4 is a schematic diagram of a power generator using a conventional reciprocating engine, Figure 5 is a schematic diagram of a power generator using a conventional single-shaft gas turbine engine, and Figure 6 is a diagram of a conventional power generator using a single-shaft gas turbine engine. A schematic diagram of a power generation device using a two-shaft gas turbine engine. FIG. 7 is a waveform diagram illustrating power generation output characteristics in a conventional device. 40... Gas turbine engine 44... High frequency power generating acid 46... Rectifier 50... Inverter 60... Fuel supply control circuit 70... Field control circuit.

Claims (1)

[Claims] (1) Includes a gas turbine engine, a high-frequency generator directly connected to the gas turbine engine, a rectifier that rectifies the output of the generator, and an inverter that converts the output of the rectifier into an alternating current signal of a desired frequency. In the gas turbine power generation device, the gas turbine engine is connected to a fuel supply controller that keeps the engine rotation speed constant, and the high frequency generator is connected to a field control circuit that adjusts the power generation output by controlling field current, A gas turbine power generation device characterized in that fluctuations in inverter output are prevented by performing both fuel supply control of the gas turbine engine and field control of the high frequency generator in response to fluctuations in the output of the high frequency generator.