JPS6318991A - Operation of shaft drive generator - Google Patents

Abstract

PURPOSE:To accelerate a control response by controlling power by a second converter connected with a bus in a ship in high frequency in both generative operation mode and motor-driven operation mode. CONSTITUTION:A shaft generator 2 driven by a main engine 1 is connected through a first converter 4 and a second converter 5 with a bus 23 in a ship. A turbine generator 20 is driven by an exhaust gas turbine 19 with exhaust gas of the engine 1 as a heat source. When the output of the generator 20 becomes excess with respect to a load in the ship, the excess power is reversely supplied to the generator 2 to aid the engine 1 as a motor drive of the generator 2. The control delay angle alpha of a first converter 4 is 0 (deg) in a generative operation mode, and the control lead angle beta of the converter 4 is limited to a limit value calculated to compensate the superposing angle to obtain a reverse voltage necessary to commutate it in a motor-driven operation mode.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to an improvement in a method of operating a shaft-driven power generation device that generates electricity using a portion of the power of a main engine of a ship.

(Prior art) As a system for economically obtaining onboard power on a ship, there is a so-called @drive power generator system that generates constant frequency, constant voltage power using a part of the power of the ship's main engine. , and a steam turbine generator system that generates electricity using the exhaust gas of the main engine as a heat source.

In ships equipped with these power generation devices, power is normally supplied to the ship's load using a steam turbine generator and a shaft drive power generator, and in order to use exhaust gas more efficiently, a turbine generator is used to When the output of the machine becomes currency, the surplus power is supplied to the @drive generator, and the shaft generator is operated electrically to support the main engine.

(Problem to be solved by the invention) In this way, general shaft drive power generators are configured so that they can be used in both power generation and electric operation modes. Since it was controlled only by the first converter on the machine side, the following problems occurred.

0) When power control is performed by the first converter, the conversion efficiency deteriorates accordingly, and the power factor of the shaft generator in the power generation operation mode deteriorates.

■ Especially when the main engine is directly connected to a shaft-driven machine,
Since control is performed at an extremely low frequency, the control response becomes poor. Therefore, in order to perform stable control, a large-capacity DC reactor is required, which poses a problem for ship-mounted equipment that is becoming increasingly lightweight. It is an object of the present invention to provide a method of operating a shaft-driven power generating device, which can improve the efficiency of the shaft-driven power generating device by improving the control response and reducing or omitting the value of the DC reactor.

(Means and Effects for Solving the Problems) The method of operating the traction power generator according to the present invention utilizes a part of the power of the main engine to drive the shaft generator, and the output power is transferred to the first and second generators. Constant voltage with second converter.

It is equipped with a shaft-driven power generator that converts it into constant frequency AC power and supplies power to the ship's load, and a steam turbine generator that uses the exhaust gas of the main engine as a heat source, and the power generator between the shafts generates power. In both operation mode and electric operation mode, the power is controlled by the second converter connected to the high-frequency inboard busbar side, and the first converter on the shaft generator side is connected to the power generation operation mode with the control delay angle α = 0 ( deg), and is characterized in that in the electric operation mode, it is operated at a control advance angle β calculated to ensure the reverse voltage necessary for commutation and to compensate for the overlap angle.

In the present invention, control response can be made faster, thereby improving control stability. Also, the value of the DC reactor can be reduced, and the axis wjA'IjJ: 9!
The efficiency of electrical equipment can be increased.

(Example) The present invention will be explained in detail below based on each drawing, but first, an inboard electric rA device including a shaft drive power generation device for carrying out the operating method of the present invention will be explained with reference to Fig. 1. do.

In Fig. 1, 1 is the main engine, 2 is a shaft generator driven by the main engine 1, and 3 is an automatic voltage adjustment device for the shaft generator 2 (
4 is a converter (hereinafter abbreviated as the first transformer), 5 is an inverter (hereinafter abbreviated as the second transformer),
6 is a DC reactor, 7 is a control device, 8 is a synchronous motor driven by the output power of the inverter 6, 9, 1
3.17.21 is AVRllo, 14.18.22 is circuit breaker, 11.15 is diesel engine for generator,
12.16 are diesel engines for generators 11.
15 is a generator driven by the exhaust gas turbine 19; 19 is an exhaust gas turbine driven by using the exhaust gas of the main engine 1 as a heat source; 20 is a turbine generator driven by the exhaust gas turbine 19;
23 is the inboard busbar.

Therefore, the shaft drive power generator shown in FIG.
controlled and operated. The details of the control device 7 are explained in the second section.
Let us explain about the figures. This figure 2 is the main part of the present invention. FIG. 4 is a circuit diagram of the control device 7 of the second converter 4°5; In FIG. 2, 31 is a power setting device that sets power for both generation and electric modes, and 32 is an output signal of the power setting device 31 and a signal (Ffb) corresponding to the frequency of the inboard bus 23.
A power control amplifier 33 compares and amplifies the output signal of the power control amplifier 32 and outputs the deviation value as a current setting signal. This is a current control amplifier that compares and amplifies a signal (I dc) corresponding to the direct current flowing between the second converters, and its output signal is the output signal of the first converter. This signal controls the current flowing through the second converter in accordance with the output signal of the power control amplifier 32.

In addition, power generation, electricity! Since the direction of DC current does not change in PII operation mode, diodes 43 and 44 and inverting amplifier 1
5, the absolute value of the output signal of the power control amplifier 32 is used as the current command. 34 is the first point at the start of control. The first converter is designed to prevent transient overcurrent flowing between the second converters 4 and 5.
．． This is a bias setting device that sets a bias value so that the phase signals of the second converters 4 and 5 are always operated from the commutation margin angle γ side. 35 is an addition circuit for the output signals of the current amplifier 33 and the bias setting unit 34; 36.37
38 is a buffer circuit, and 38 is a mode discrimination circuit that discriminates between power generation and electric operation modes based on the output polarity of the power control amplifier 32.

39 is a first phase limit circuit of the first converter which limits the output (i) of the adder circuit 35 which is sent to the first converter 4 via the buffer circuit 36.The details of this first phase limit circuit 39 are as follows. In FIG. 3 shown, R1 to R9 are resistors, 51A and 51B are the output contacts of the mode discrimination circuit 38 in FIG. 2, and in the power generation mode, 51A is closed and 51
B is open, 51A is open in electric mode, 51
B is a closing action. 52 and 53 are operational amplifiers, and 54 is an α limit setter that sets the limit value of the control delay angle α of the first converter 4 in the power generation mode, and normally α=
It is set to O(dge).

Therefore, in the power generation mode, the output control signal of the adder circuit 35 sent to the first converter 4 via the buffer circuit 36 in FIG. 1, that is, the control delay angle α of the first converter 4 is at its limit value. On the other hand, in the electric mode, the signal (Vsg) according to the output voltage of the shaft generator and the
．． The first converter 4 calculates a limit value in order to ensure the reverse voltage necessary for commutation and to compensate for the overlap angle U by the signal (I da) corresponding to the DC current between the second converter. be done.

Therefore, in this mode, the output of the adder circuit 36 is sent via the buffer circuit 36 to the first converter 4? No. a, that is, the control advance angle β of the first converter 4 is limited to the above-described calculated β limit value.

Here, the control advance angle β has the following relationship. .

β=γ+U U: Commutation type angle γ: Commutation margin angle Meanwhile, 40 in FIG. 2 is the second phase limit circuit of the second converter. In FIG. 4 showing the second phase limit circuit 40, R21 to R24 are resistors, 64 and 65 are operational amplifiers, and 61 determines the limit value of the control advance angle β of the second converter 5 in the power generation mode. 62 is an α angle setter that determines the limit value of the control delay angle α of the second converter 5 in the electric mode, and 63 is an output contact of the mode discrimination circuit 38 shown in FIG.

It is open in power generation mode and closed in electric mode. Therefore, in the power generation mode, the β limit value of the control advance angle β of the second converter is set by the β angle setter 61, and in the electric mode, the α limit value of the control delay angle α of the second converter is set by the α angle. It is set by the setting device 62.

In addition, 41 and 42 in FIG. 2 are constant voltage diodes that transmit the current control signal, which is the output signal of the adder circuit 35, to the buffer circuit 37 in order to control the power with the second converter S in both the power generation and electric surface modes. , the constant voltage diode 41 is the second
In combination with the β limit set by the phase limit circuit 40, the output signal of the adder circuit 35 is transmitted to the first phase limit circuit 3.
When the α limit value set in 9 is reached, it will be adjusted around 4
The constant voltage diode 12 is set so that the output signal of the adder circuit 35 is set at the α limit set by the second phase limit circuit 39 in combination with the α limit set by the second phase limit circuit 40. It is set to conduct until the limit value is reached. Note that 43 and 44 in FIG. 2 are diodes connected in series to the constant voltage diodes 41 and 42 in order to prevent reverse flow of signals from the constant voltage diodes.

Therefore, the first converter 4 is normally operated in each of the generation and electric modes at α and β angles determined by the first limit circuit 39 in FIG. Upper limits are set for α and β determined by the second phase limit circuit 40 in each mode.

It is controlled by a current control signal output from the adder circuit 35 as a lower limit value. As a result, power can be controlled on the inboard busbar side, which has a high frequency.

The operation of the circuits shown in FIGS. 1 and 2 will be explained below with reference to FIGS. 5 and 6. In the figures, FIG. 5 shows the characteristics of the control device in the power generation mode, and FIG. 6 shows the characteristics of the control device in the electric mode.

Note that 'F''' II J 11 are phase signals output to the first and second converters 4°5, respectively, and 11 E II
indicates the output signal of the adder circuit 35.

First, when the power setting device 31 shown in FIG. is given as a current command to the current control amplifier 33 via. At this time, the mode discrimination circuit 38 discriminates the power generation mode based on the output polarity of the power control amplifier 32, and the first . The mode of the second phase limit circuit 39, 40 is switched to the power generation mode.

Therefore, depending on the above-mentioned current command, the first. Second converter 4, 5
Control signals of control delay angle α and control advance angle β output to
That is, LI J II and u F 11 are respectively 1st. The value set by the power generation mode of the second phase limit circuit 39, 40 is limited as the upper and lower limit values, and control is performed within that range. At this time, the first phase limit circuit 39 controls the control delay angle α to improve the power factor of the shaft generator.
= 0 (deg), and the second phase limit circuit 40
is set to a limit value β at which the second converter 5 does not cause commutation failure.

Note that the constant voltage diode 41 is connected to the phase signal 1 of the first converter (
When the potential of "F" reaches the limit value (Figure 5 LL C1
1 point) Since the voltage characteristics are selected so that conduction starts around the same time, as the output signal of the adder circuit 35 increases, the potential of the phase signal II J 11 of the second converter changes to the second phase limit circuit 40. It increases from the β limit value set by .

In this way, the phase of the first converter 4 is always operated at α = 0 (deg), which has the highest conversion efficiency, regardless of the amount of power generated, and the
ff! , the power is supplied to the second converter 5 on the inboard busbar side with high frequency.
Since the power factor and control response of the shaft generator in power generation mode are improved.

By the way, normally, as explained above, the phase of the first converter 4 is always operated with α=○, but if the shaft generator voltage rises above the rated value, the direct current of the first converter 4 - Since the voltage also tends to rise, the DC current between the first and second converters also increases, and as a result, the phase lead angle of the second converter 5 is fixed at the β limit, and the phase lag angle α of the first converter 4 is fixed. increases, and the first. The direct current between the second converters is limited.

Conversely, if the shaft generator voltage decreases below the rated value,
The phase delay angle α of the first converter 4 remains α=0, the phase advance angle β of the second converter 5 increases, and the DC current between the first and second converters is controlled to be constant. Ru.

On the other hand, when the power setting device 31 is set to the electric side, the power setting device 31
output signal and a signal corresponding to the frequency of the inboard bus (F fb
) is amplified by the power control amplifier 32.

It is given as a current command to the current control amplifier 33 via the inverting amplifier 45 and the diode 44. At this time, the mode discrimination circuit 38 discriminates the electric mode based on the output polarity of the power control amplifier 32, and selects the first mode. Second phase limit circuit 39
．． Switch the mode of 40 to electric mode.

Therefore, depending on the above-mentioned current command, the first. second converter 4,
The control signals of the control delay angle α and control advance angle β output to
, the values set by the electric mode of the second phase limit circuit 39, 40 are set as upper and lower limit values, and control is performed within these limits. At this time, the first phase limit circuit 39 outputs a signal (Vsg
) and 1st. A signal (I
The control advance angle β is limited to a limit value determined by dC). This ensures that even if the rotational speed of the main engine 1 drops below the rated operating range and the output voltage of the shaft WLa drops, the reverse voltage necessary for commutation of the first converter 4 is secured, and the commutation This is to compensate for the mold angle U. Further, the second phase limit circuit 40 is usually set to an appropriate value, for example, about 15 (deg) to prevent commutation failure of the second converter 5, and the I
I J 11 is restricted.

In this way, the phase of the first converter 4 maintains the optimum conversion efficiency and is operated at a limit value that does not cause commutation failure, and the power is controlled by the second converter 5 on the inboard busbar side, which has a high frequency, so it is optimal. It can be operated with high conversion efficiency, and control response is improved.

Here, when the power setter 31 is set to an extremely low setting value on the electric side, the current control amplifier 33. The signal of the adder 35 is also low, and the potential of the phase signal 11 J II of the second converter is limited by the output of the adder 35 via the constant voltage diode 42, so the output of the second converter is also low and the electric power amount is low. is also low, and as the power setter 31 is increased, the current control amplifier 33. The adder 35 also increases, and the phase signal of the second converter, which was limited by the constant voltage diode 42, increases by +1 J.
The electric potential of 11 increases in accordance with the output signal of the adder 35 within a range whose upper limit is the α limit determined by the second phase limit circuit, and the electric power amount is controlled.

〔Effect of the invention〕

As explained above, in the present invention, power is always controlled by the second converter connected to the high-frequency inboard busbar side in both the power generation operation mode and the electric operation mode, and the first converter on the shaft generator side is used to control the electric power. In power generation mode, α has the highest conversion efficiency.
= 0 (deg), and in the electric operation mode, it operates at a control advance angle β calculated to ensure the reverse voltage necessary for commutation and to compensate for the overlap angle, Control response can be made faster, thereby improving control stability. In addition, this allows the value of the DC reactor to be reduced, and in particular, in a shaft power generation system in which the shaft generator is directly connected to the main engine, the DC reactor can be omitted because the shaft generator has a high actance. Furthermore,
9! In electric mode, the converter can be limited to the control delay angle with the best conversion efficiency, so the generator can be operated with the best power factor, and in electric mode, the conversion efficiency can be optimized. It can be operated at all times, increasing the efficiency of the shaft power generator.

[Brief explanation of drawings]

The mounting part is a diagram showing the configuration of an inboard power supply system including a shaft drive power generator for carrying out the operating method of the l1Il drive VJ power generator according to the present invention, and FIG. FIGS. 3 and 4 are block diagrams showing an embodiment of the first and second phase limit circuits, and FIGS. 5 and 6 are block diagrams for explaining the present invention in detail. It is an explanatory diagram. 1... Main engine 2... Shaft generator 4... First converter 5... Second converter 7... Control device
8... Synchronous electric machine a 18... Mode discrimination circuit
19...Exhaust gas turbine 20...Turbine generator 31...Generation, electric power mode power setting device 39...First phase limit circuit 40...Second phase limit circuit Agent Patent attorney Yoshiaki Inomata (1 other person) Figure 1 Figure 2 Figure 3 Figure 4 Moxibustion threat 1 and Figure 5 41 □6゜

Claims (1)

[Claims] (1) A portion of the power from the main engine is used to drive the shaft generator, and the output power is converted into constant voltage, constant frequency AC power by the first and second converters to power the onboard loads. and a steam turbine generator that uses the exhaust gas of the main engine as a heat source. In the power generation operation mode, the control delay angle is set to α = 0 (deg), and in the electric operation mode, the control delay angle is set to α = 0 (deg), and in the electric operation mode, the control delay angle is A method for operating a shaft-driven power generator, characterized by operating at a control advance angle β calculated to ensure voltage and compensate for an overlap angle.