WO2017149588A1

WO2017149588A1 - Ship propulsion device and ship propulsion method

Info

Publication number: WO2017149588A1
Application number: PCT/JP2016/056007
Authority: WO
Inventors: 正識古寺; 浩二竹居; 信治田代; 浩一白石; 拓郎畑本
Original assignee: 新潟原動機株式会社
Priority date: 2016-02-29
Filing date: 2016-02-29
Publication date: 2017-09-08
Also published as: JP6640324B2; JPWO2017149588A1

Abstract

[Problem] To stabilize the rotational speed of an engine generator in a ship propulsion device that is capable of electric propulsion. [Solution] A ship propulsion device 1 that has: an engine generator 4; a propulsion motor 9; an inverter 8 that performs torque control on the motor; a deviation limiter 16 that controls the deviation between the actual value and a target value for motor rotational speed to a prescribed value or less; and a PID regulator that computes a torque command value such that the deviation decreases and that outputs the torque command value to the inverter. Parameters for the PID regulator are set as appropriate, and the response speed of the inverter is matched to the response speed of the engine generator. Variation in the power supplied to the motor is kept to an amount to which the engine generator can respond, the engine generator is prevented from hunting, and the rotational speed of the engine generator is stabilized.

Description

Ship propulsion device and ship propulsion method

The present invention relates to a marine vessel propulsion apparatus in which an inverter torque-controls a motor by electric power of an engine generator, and in particular, by realizing an inverter response speed that matches the response speed of the engine generator, the engine generator performs hunting. The present invention relates to a marine vessel propulsion device that can prevent the occurrence of the fluctuation and suppress the fluctuation amount of the electric power supplied from the inverter to the motor to a fluctuation amount that the engine generator can respond to, thereby stabilizing the rotation speed of the engine generator.

An electric propulsion ship system stabilization system described in Patent Document 1 includes an electric motor that drives a load facility such as a propeller provided in an electric propulsion ship, and electric power supplied from the generator to the system at a desired voltage. And an inverter that controls the motor by converting to a frequency, a wave detector that detects the height and period of a wave generated in the vicinity of the electric propulsion ship, and a wave height and a wave period detected by the wave detector In particular, the system stabilization device imposes a limit on the upper operation speed limit for the inverter when the occurrence of an abnormal environment is predicted. The load current is reduced. More specifically, the grid stabilization system further includes an AVR control unit that controls the excitation voltage of the generator and a governor control unit that controls a governor provided corresponding to the drive device for the generator. When the occurrence of an abnormal environment is predicted, the system stabilization device calculates the voltage adjustment rate for the generator and the governor adjustment rate for the drive unit based on the change rates of the output current and frequency of the inverter. The calculation result is output to the AVR control unit and the governor control unit to stabilize the system voltage and frequency.

Further, the invention described in Patent Document 2 is not related to an electric propulsion ship but relates to a vehicle drive control device. The vehicle drive control device according to the present invention is a vehicle drive control device including a generator and an AC motor that is supplied with electric power from the generator via an inverter to drive drive wheels. Field control means for controlling the field of the generator based on required motor power, torque command value calculating means for calculating a torque command value of the AC motor based on required motor power required by the AC motor, and Motor control means for controlling the AC motor based on the torque command value calculated by the torque command value calculation means and the output state of the generator. The motor control means is configured to output the torque command based on a torque corresponding to an operating point at which a voltage value is a voltage upper limit value on a generator output characteristic line including an operating point determined from the output voltage and output current of the generator. A lower limit is set on the value, and an upper limit is set on the torque command value by the torque corresponding to the operating point at which the output power is maximum on the generator output characteristic line including the operating point determined from the output voltage and output current of the generator. Torque command value limiting means is provided, and the AC motor is controlled based on the torque command value limited by the torque command value limiting means. That is, the same document 2 describes that when a torque command value to an inverter that performs torque control of an AC motor is output, an upper limit and a lower limit are provided for the torque command value according to the situation of the generator.

JP 2010-89550 A Japanese Patent No. 4466542

According to the invention of the system for stabilizing a system of an electric propulsion ship described in the above-mentioned Patent Document 1, there are the following problems.
1) A system stabilization device that stabilizes the generator rotation speed, the system voltage and frequency, and a wave detector that detects information for the system stabilization device to predict the occurrence of an abnormal environment are required. The structure is complicated.
2) Adjustment is required for both the governor for controlling the engine rotational speed of the engine generator and the AVR for controlling the excitation voltage of the generator, and there are many parameters to be adjusted and the control is complicated.

Further, according to the vehicle drive control device described in Patent Document 2, when the torque command value to the inverter is output, in order to provide an upper limit and a lower limit for the torque command value, There is a problem that information is required, various sensors must be provided, the controller is complicated, and the adjustment is complicated.

Furthermore, motor propulsion ship propulsion devices (including hybrid propulsion) in which an inverter controls the rotational speed of a motor by electric power supplied from an engine generator are known. When the motors have approximately the same capacity, it has been noticed that the rotational speed of the generator tends to fluctuate easily due to the following factors.

(1) When the inverter controls the rotation speed of the motor according to the speed command value from the controller, the inverter performs high gain feedback control with excellent instantaneous response to fluctuations in the motor rotation speed, and the motor rotation speed Is adjusted according to the speed command value from the controller, and the motor output is adjusted at high speed. Therefore, the motor output tends to fluctuate greatly instantaneously. However, the momentary fluctuation of the motor output in this way is stressful for the engine generator that supplies power to the motor, so the capacity of the engine generator is set to about three times the capacity of the motor, for example. It is necessary to secure a margin for motor load fluctuations.

(2) Thus, if the motor output fluctuates at high speed, the load of the engine generator will fluctuate at high speed. Therefore, the control device for the engine generator controls the rotation speed of the engine with a high gain in order to make the rotation speed follow the rapid fluctuation of the load of the engine generator. However, when the engine of the engine generator is a diesel engine and the generator and the motor have the same capacity, the feedback control of the governor due to the response delay of the engine generator against the high speed fluctuation of the motor output. Therefore, in the high gain feedback control as described above, the number of rotations of the generator hunts and the frequency and voltage fluctuate and the control system tends to become unstable.

Note that hunting is a phenomenon in which the frequency and voltage become unstable in an electric device such as a generator, causing trouble in the operation of the electric device. If the frequency or voltage of an electrical device becomes unstable, for example, the limit value or range that the electrical device can operate without any problem, the voltage is + 6% and -10% in the steady state and in the transitional period. If there is, the frequency is ± 20% (within 1.5 seconds), and the frequency is ± 5% in the steady state and ± 10% (within 5 seconds) in the transient period. Note that the limit value or range in which such an electric device can operate without hindrance may vary depending on the type and application (application field) of the electric device. As described above, in this specification, a phenomenon in which the frequency and voltage are destabilized beyond the range in which various electric devices can operate without problems within the intended range is called hunting.

The following two factors can be cited as the cause of the response delay of the engine generator described above. 1) A point where it takes time for the fuel injected from the injector to burn and become kinetic energy (combustion delay).
2) There is a time lag (physical delay) before the turbocharger of the engine generator responds to load fluctuations.

As described above, in the ship propulsion device capable of motor propulsion including hybrid propulsion, when the generator and the motor have the same capacity, the problem that the generator rotational speed is likely to fluctuate is significant. .

An object of the present invention is to solve the above-described problems. In a marine vessel propulsion apparatus in which an inverter torque-controls a motor by electric power of an engine generator, the engine power generation is performed without depending on control based on information on the generator side. By realizing the inverter response speed that matches the machine response speed, the engine generator is prevented from hunting, and the fluctuation amount of power supplied from the inverter to the motor is changed to the fluctuation quantity that the engine generator can respond to. It aims at providing the ship propulsion apparatus which can suppress and stabilize the rotational speed of an engine generator.

The marine vessel propulsion device described in claim 1 is:
An engine generator that generates electric power by driving a generator with an engine;
A motor for propelling the ship;
An inverter for torque controlling the motor using electric power supplied from the engine generator;
In the mechanism for outputting a torque command value to the inverter based on the deviation between the current rotation speed of the motor and the target rotation speed, the amount of change per unit time of the torque command value output to the inverter is A torque command value limiting unit for limiting the engine generator so that the response speed of the inverter does not cause hunting;
It is characterized by comprising.

The ship propulsion device described in claim 2 is the ship propulsion device according to claim 1,
The torque command value limiting unit is a PID regulator that PID-calculates a torque command value and outputs the torque command value to the inverter, and the engine generator does not cause hunting for a change amount per unit time of the torque command value. The PID regulator is set with a PID parameter that limits the response speed of the inverter.

The ship propulsion device described in claim 3 is the ship propulsion device according to claim 1,
The torque command value limiting unit is a deviation limiter that limits a deviation between a current rotation speed of the motor and a target rotation speed within a predetermined value range.

The ship propulsion device described in claim 4 is the ship propulsion device according to claim 1,
The torque command value limiter is
A deviation limiter for limiting the deviation between the current rotational speed of the motor and the target rotational speed within a predetermined value range;
A PID regulator that performs a PID calculation of a torque command value so as to reduce a deviation output from the deviation limiter, and outputs the torque command value to the inverter, wherein the engine generator determines the amount of change per unit time of the torque command value. A PID regulator in which a PID parameter to be limited is set so that the response speed of the inverter does not cause hunting;
It is characterized by consisting of.

The marine vessel propulsion device according to claim 5 is the marine vessel propulsion device according to any one of claims 1 to 4,
It has a lower limiter that provides a lower limit to the torque command value calculated by the PID regulator.

The ship propulsion apparatus according to claim 6 is the ship propulsion apparatus according to any one of claims 1 to 5,
A speed limiter command is calculated by adding a preset constant to the target rotational speed of the motor, and the speed limiter command is output to the inverter to prevent over-rotation of the motor. It is a feature.

The ship propulsion method described in claim 7 is:
A ship propulsion method for propelling a ship by supplying electric power generated by driving the engine of an engine generator that drives the generator with an engine via an inverter that torque-controls the motor. ,
The amount of change per unit time of the torque command value output to the inverter is limited to the response speed of the inverter at which the engine generator does not cause hunting.

The ship propulsion method described in claim 8 is the ship propulsion method according to claim 7,
A PID parameter is set to limit the amount of change per unit time of the torque command value output by performing PID calculation to the inverter to the response speed of the inverter where the engine generator does not cause hunting. Is output to the inverter. The ship propulsion method according to claim 7.

The ship propulsion method according to claim 9 is the ship propulsion method according to claim 7,
The deviation between the current rotation speed of the motor and the target rotation speed is limited within a predetermined value range, and the torque command value is calculated so that the limited deviation becomes small, and then output to the inverter. The amount of change per unit time of the torque command value to be limited is limited to the response speed of the inverter at which the engine generator does not cause hunting.

The ship propulsion method according to claim 10 is the ship propulsion method according to claim 7,
Limiting the deviation between the current rotational speed of the motor and the target rotational speed within a predetermined value range;
Setting a PID parameter that limits the amount of change in the torque command value to be output per unit time so that the response speed of the inverter does not cause hunting by the engine generator,
A torque command value calculated by PID so as to reduce the limited deviation is output to the inverter.

The ship propulsion method according to claim 11 is the ship propulsion method according to any one of claims 7 to 10,
A lower limit is provided for the calculated torque command value.

The ship propulsion method according to claim 12 is the ship propulsion method according to any one of claims 7 to 11,
A speed limiter command is calculated by adding a preset constant to the target rotational speed of the motor, and the speed limiter command is output to the inverter to prevent over-rotation of the motor.

According to the marine vessel propulsion apparatus described in claim 1 and the marine vessel propulsion method described in claim 7, the marine vessel propulsion apparatus including an engine generator, a propulsion motor, and an inverter that controls torque of the motor. The amount of change in power output from the inverter to the motor is limited by limiting the amount of change per unit time in the torque command value output to the inverter to the response speed of the inverter where the engine generator does not cause hunting. Is the amount of fluctuation that the engine generator can respond to.
That is, by restricting the amount of change per unit time of the torque command value, the response of the inverter is “dulled” so that the engine generator does not hunt in accordance with the response of the engine generator. It is.
Conventionally, there has been a need to secure a margin for motor load fluctuation by setting the capacity of the engine generator to about three times the motor capacity, but the present invention addresses the necessity of this engine generator margin. The capacity of the engine generator can be made smaller than before.

Limiting the amount of change per unit time in the torque command value output to the inverter can be achieved by the ship propulsion device described in claim 2 and the ship propulsion method described in claim 8.
That is, the amount of change per unit time of the torque command value is limited by the PID parameter value of the PID regulator so that the responsiveness of the electric power output to the motor matches the response speed (response delay) of the engine generator. The response of the inverter is “dulled” so that the engine generator does not hunt according to the response of the engine generator. In other words, the responsiveness of the motor in the marine vessel propulsion apparatus that performs electric propulsion is comparable to that in the case of driving a propeller in a marine vessel propulsion apparatus that uses a diesel engine as a main engine.

Thus, since the fluctuation amount of the generator load, that is, the fluctuation amount of the electric power output from the inverter to the motor is suppressed within the fluctuation amount range that the engine generator can respond to, the engine generator only by governor control. The rotation speed and frequency of the engine generator can be stabilized, and adjustment of the governor and AVR in the engine generator is unnecessary. In this control, data from the engine generator is not required, nor is it intended to control the engine generator itself.

Moreover, in order to restrict | limit the variation | change_quantity per unit time of the torque command value output to the said inverter, it can also achieve by the ship propulsion apparatus described in Claim 3, and the ship propulsion method described in Claim 9.
According to the marine vessel propulsion device described in claim 3 and the marine vessel propulsion method described in claim 9, the deviation between the current rotational speed of the motor and the target rotational speed is within a predetermined value range by a deviation limiter. Even if the torque command value is calculated based on the limited deviation by a normal converter (for example, a proportional device) instead of the PID regulator in which the specific PID parameter value is set as described above, Since the input value is sufficiently limited, the amount of change per unit time of the torque command value output to the inverter can be limited.
Thereby, the above-mentioned effect can be produced similarly.

Furthermore, the amount of change per unit time in the torque command value output to the inverter can be limited by the ship propulsion device described in claim 4 and the ship propulsion method described in claim 10.
That is, the amount of change per unit time of the torque command value output to the inverter is also achieved by the ship propulsion device that combines claim 2 and claim 3 and the ship propulsion method that combines claim 8 and claim 9. Can be limited.
According to the ship propulsion device described in claim 4 and the ship propulsion method described in claim 10, the deviation between the rotational speed of the motor and the target rotational speed is limited to be a predetermined value or less, Further, a PID parameter is set to limit the engine generator to a response speed of the inverter that does not cause hunting, and a torque command value calculated by PID is output to the inverter so that the limited deviation becomes small. Since it did in this way, the variation | change_quantity per unit time of the torque command value output to the said inverter can also be restrict | limited by this.

In this case, the adjustment of the PID parameter value for preventing the engine generator from hunting does not need to be set to “strictly dull” the response of the inverter as compared with the case where the deviation is not limited. May be. That is, the effect required to stabilize the rotational speed and frequency of the engine generator can be obtained without bringing the response speed of the inverter close to the response speed of the engine generator as in the case where the deviation is not limited.

Further, when the PID parameter is set appropriately, the inverter response speed is brought close to the engine generator response speed, and a certain effect of preventing hunting of the engine generator is obtained. If the control is performed, it is possible to avoid an extreme change in the power output to the motor by the inverter, which is expected when the deviation is large, and to further synergize the rotation speed and frequency of the engine generator Is obtained.

According to the marine vessel propulsion apparatus described in claim 5 and the marine vessel propulsion method described in claim 11, for example, the lower limit can be set to 0 or more to reduce the regenerative electric energy of the motor, and the lower limit It is also possible to set the limit to less than 0 so that the regenerative electric energy of the motor is present.

According to the ship propulsion device described in claim 6 and the ship propulsion method described in claim 12, the speed limiter command calculated by adding a set constant to the target rotational speed of the motor is output to the inverter. Over-rotation can be prevented.

It is a control block diagram of the ship propulsion apparatus of a 1st embodiment. It is a graph which shows the effect | action or function of the deviation limiter in the ship propulsion apparatus of 1st Embodiment. It is a graph explaining the effect | action or function of a PID regulator which adjusts the response speed of an inverter so that it may become close to the response speed of an engine generator in the ship propulsion apparatus of 1st Embodiment. It is a graph which shows the control by the lower limiter of the motor rotational speed in the ship propulsion apparatus of 1st Embodiment, and the fractional diagram (a) shows the case where a minimum limit is set to less than 0, and the same fractional diagram (b) is a minimum limit. Is set to 0 or more. It is a control flow figure of a vessel propulsion device of a 1st embodiment. It is a table | surface which shows the correspondence of the handle position of the speed control handle in the ship propulsion apparatus of 1st Embodiment, and a motor target rotational speed. It is a control block diagram of the ship propulsion device of a 2nd embodiment.

The ship propulsion apparatus of the first embodiment will be described with reference to FIGS. This marine vessel propulsion device is a device that propels a vessel by controlling the torque of the motor by the inverter using electric power generated by the engine generator under the control of the controller, and the motor rotates the propeller.

The configuration of the marine vessel propulsion apparatus 1 will be described with reference to FIGS.
As shown in FIG. 1, the marine vessel propulsion apparatus 1 includes an engine generator 4 that generates electric power by driving a generator 3 with an engine 2. The engine 2 is controlled by a governor 5 having a function of autonomously adjusting the rotational speed of the engine 2. The generator 3 has an excitation voltage controlled by an AVR (Automatic Voltage Regulator) 6. The generator control device 7 can detect the current and voltage frequency of electricity generated by the generator 3, and can control the governor 5 and AVR 6 based on this.

As shown in FIG. 1, the electric power from the engine generator 4 is given to the motor 9 through the inverter 8, and the motor 9 is driven to rotate the propeller 10. The inverter 8 is controlled by the controller 11. The controller 11 has a configuration described below for rotational speed stabilization control of the engine generator 4.

As shown in FIG. 1, the controller 11 has a speed calculation unit 13. A speed control handle 12 installed at the operating position of the ship is connected to the speed calculation unit 13. The speed control handle 12 outputs a signal corresponding to the position operated and set by the operator. The speed calculation unit 13 receives a signal from the speed control handle 12 and calculates a motor target rotation speed based on this signal.

As shown in FIG. 1, a speed limiter 14 is connected to the speed calculation unit 13. The speed limiter 14 calculates a speed limiter command by adding a set constant α to the motor target rotation speed calculated by the speed calculation unit 13 and gives it to the inverter 8. The setting constant α is set so as to be less than the maximum allowable rotation speed of the motor 9 even when the setting constant α is added to the maximum motor target rotation speed when the speed control handle 12 is maximized. That is,
(Allowable maximum motor speed-maximum motor target speed)> Setting constant α
Are in a relationship. As a result, the inverter 8 cannot drive the motor 9 beyond the speed limiter command, and over-rotation of the motor 9 is prevented.

As shown in FIG. 1, a deviation calculator 15 is connected to the speed calculator 13. The motor target rotation speed is input from the speed calculation unit 13 to the deviation calculation unit 15. This deviation calculation unit 15 is also connected to the inverter 8, and the current motor rotation speed is input from the inverter 8. The deviation calculation unit 15 calculates a deviation between the motor target rotation speed and the motor rotation speed.

As shown in FIG. 1, a deviation limiter 16 is connected to the deviation calculation unit 15. The deviation is input from the deviation calculator 15 to the deviation limiter 16. The deviation limiter 16 limits the deviation to be within the range of each deviation limiter value on the + side and − side according to the following (Equation 1) so that the instantaneous fluctuation amount of the motor output does not increase, and outputs it. . The deviation that is limited and output by (Equation 1) is expressed in particular as deviation E (n).

Lower limit deviation limiter value ≤ E (n) (deviation) ≤ upper limit deviation limiter value (Equation 1)

That is, in FIG. 2, the horizontal axis indicates the deviation that is the difference between the motor target rotational speed and the actual motor rotational speed, and the vertical axis indicates the deviation E (n) that is actually output from the deviation limiter 16. Yes. If the deviation on the horizontal axis is relatively narrow before and after 0, it is output as the deviation E (n) on the vertical axis as it is, but if it exceeds a range of ±, the lower limit deviation limiter value that is the limit value shown on the vertical axis And output as a deviation E (n), limited to the upper limit deviation limiter value.

As shown in FIG. 1, a PID regulator 17 is connected to the deviation limiter 16. The PID regulator 17 is set with a PID parameter value that realizes the response speed of the inverter 8 so that the engine generator 4 does not hunt, that is, a parameter value that matches the response speed of the engine generator 4, and the deviation E ( Calculate and output the torque command value so that n) becomes smaller.

As shown in FIG. 3, the response speed (solid line) of the inverter 8 that drives the motor 9 is larger than the response speed (broken line) of the engine generator 4. That is, when compared with the response characteristics, the rise of the output with respect to time is faster and steeper in the inverter 8 than in the engine generator 4. Therefore, the PID regulator 17 adjusts the PID parameter in the PID control of the torque command for the inverter 8, thereby reducing the response speed of the inverter 8 to be equal to or lower than the response speed of the engine generator 4 (one-dot chain line) and Is matched with the response speed of the engine generator 4. That is, the amount of change per unit time of the torque command value is changed by the PID regulator 17 that has adjusted the PID parameter based on the deviation E (n) between the current rotational speed of the motor and the target rotational speed. The torque command value that is a value that does not cause the hunting of 4 is output to the inverter 8.
As a result, the amount of change per unit time of the torque command value is limited, and the responsiveness of the inverter apparently becomes “dull”, and the engine generator is hunted according to the responsiveness of the engine generator. Will not do. Thereby, the responsiveness of the motor 9 in the marine vessel propulsion apparatus 1 that performs electric propulsion becomes approximately the same as the responsiveness when the propeller is driven in the marine vessel propulsion apparatus that uses a diesel engine as a main engine.

More specifically, based on the deviation E (n) calculated and limited by the deviation limiter 16, the torque command value is calculated according to the following (Expression 2) or (Expression 3). This is a typical example of a PID arithmetic expression in software digital arithmetic processing.

Speed type PID calculation formula Torque command calculation value = Kp x {(E (n) -E (n-1)) + Δt / Tl x E (n)
+ Td / Δt (E (n) -2E (n-1) + E (n-2))
Torque command value (n) = Torque command value (n-1) + Torque command calculation value ... (Formula 2)

For position type PID calculation formula Torque command calculation value = Kp x {(E (n) + Δt / Tl x ΣEi
+ Td / Δt (E (n) -E (n-1)) (Formula 3)

In each of the above formulas,
Kp: Proportional gain (P minutes) Tl: Integration time (I minutes) Td: Derivative time (D minutes) Δt: Calculation period E (n): Limited value calculated from (Equation 1) (deviation)

The calculation cycle Δt corresponds to the “unit time” in the “amount of change per unit time of the torque command value output to the inverter 8” described above. Usually, this calculation cycle is 1 msec to several seconds, preferably 10 to 500 msec. The “change amount” is incorporated into the PID parameters proportional gain (P) Kp, integral time (I) Tl, and derivative time (D) Td, and the change per unit time of the torque command value Is output from the PID regulator to a value that does not cause hunting of the engine generator 4.

In other words, the PID regulator 17 adjusts the PID parameters in advance so that the rotation speed of the engine generator does not hunt when a load is applied to the motor 9. The value of this PID parameter is determined in accordance with the characteristics of the engine generator 4 and the characteristics of the inverter 8. This adjustment is performed at the beginning of the operation of the ship propulsion apparatus 1, such as a trial operation, and once set, no further adjustment is necessary.
Hereinafter, the adjustment of the PID parameter will be described for each component.

P component parameter adjustment When the rotation speed of the engine generator 4 is greatly reduced momentarily when the load of the motor 9 is suddenly increased, or when the load of the motor 9 is suddenly reduced, the rotation speed of the engine generator 4 is instantaneous. If the change greatly changes, the P minute parameter is adjusted to a value smaller than the current value. The P minute parameter adjustment affects the I minute and D minute parameter adjustments. Therefore, when the P minute parameter is adjusted, the I minute and D minute parameters are readjusted as necessary.

I-minute parameter adjustment When the load fluctuation of the motor 9 is small and the rotational speed of the engine generator 4 is hunting, the I-minute parameter is adjusted to a value smaller than the current value. Since the I minute parameter adjustment affects the P minute D minute parameter adjustment, if the I minute parameter is adjusted, the P minute and D minute parameters are readjusted as necessary.

D component parameter adjustment When the rotational speed of the engine generator 4 temporarily overshoots or undershoots when the load of the motor 9 changes suddenly, the D component parameter is adjusted to a value smaller than the current value. Since the D minute parameter adjustment affects the P minute I minute parameter adjustment, if the D minute parameter is adjusted, the P minute and I minute parameters are readjusted as necessary.

After adjusting the parameters of P, I and D for a while, the speed control handle 12 is moved to increase the rotational speed of the motor 9 (propeller 10), thereby increasing the load on the generator 3. Along with this, the state in which the governor 5 automatically adjusts to increase the output of the engine 2 is observed, and it is confirmed whether the engine generator 4 has caused hunting. If hunting is to occur, readjust the parameters for P, I, and D according to the above guidelines, and if it is confirmed that hunting has not occurred, adjustment of parameters for P, I, and D is complete. It is. Normally, those skilled in the art can complete the parameter adjustment for P minutes, I minutes, and D minutes in 3 to 6 hours.

As shown in FIG. 1, a lower limiter 18 is connected to the PID regulator 17. The torque command calculated by the PID regulator 17 is input to the lower limiter 18. The lower limiter 18 limits the torque command calculated by the PID regulator 17 and outputs it to the inverter 8 according to the following (Equation 4) so that the instantaneous fluctuation amount of the motor output does not increase.

Lower limit value ≤ Torque command value (Equation 4)

As shown in FIG. 4, the motor regenerative electric energy can be arbitrarily limited by changing the setting of the lower limiter value.
FIG. 4A shows changes in the rotational speed and the operating state of the motor 9 when the lower limiter value is less than zero. When the lower limiter value is less than 0, the motor regenerative electric energy can be set to “present”. As indicated by a thin line ellipse attached to the motor output (dashed line), the motor regenerative power is generated and the energy is recovered, so the motor rotation speed (broken line) is compared with FIG. falling.

FIG. 4B shows changes in the rotational speed and the operating state of the motor 9 when the lower limiter value is 0 or more. If the lower limiter value is 0 or more, the motor regenerative electric energy can be set to none. Since the motor output (one-dot chain line) is power running or 0, the marine vessel is not braked, and the motor rotation speed (broken line) falls slower than that shown in FIG. 4A.

As shown in FIG. 1, the lower limiter 18 is connected to the inverter 8, and a torque command to which the lower limiter is given by the lower limiter 18 is given to the inverter 8.

Next, the control procedure in the ship propulsion apparatus 1 will be described with reference to FIG. In the figure, Y means YES and N means NO.
After the start of the control operation (START), when a crew member of the ship sets the position where the speed control handle 12 is operated, a signal corresponding to the position is sent to the speed calculation unit 13 of the controller 11, and the speed calculation unit 13 calculates the corresponding motor target rotational speed from this signal (S1).

The speed calculation unit 13 outputs the motor target rotation speed to the speed limiter 14. The speed limiter 14 adds a set constant α to this to calculate a speed limiter command (S2), and outputs it to the inverter 8. As a result, the inverter 8 cannot drive the motor 9 beyond the speed limiter command, and over-rotation of the motor 9 is prevented.

The speed calculation unit 13 outputs the motor target rotation speed to the deviation calculation unit 15. On the other hand, the inverter 8 outputs a motor rotation speed signal to the deviation calculator 15. The deviation calculator 15 calculates a deviation between the motor target rotation speed and the motor rotation speed (S3).

The deviation calculation unit 15 outputs the deviation to the deviation limiter 16. The deviation limiter 16 limits the deviation to be less than the deviation limiter values on the + side and − side according to the above (Equation 1) so that the instantaneous fluctuation amount of the motor output does not exceed a predetermined range. (S4).

That is, when the deviation is a value between the lower limit deviation limiter value and the upper limit deviation limiter value (S4, Y), the actual deviation between the motor target rotation speed and the motor rotation speed is calculated as the calculated deviation E (n). Output (S5).

If the deviation is not a value between the lower limit deviation limiter value and the upper limit deviation limiter value (S4, N), and the deviation exceeds 0 (S6, Y), the calculated deviation E (n) (S7).

When the deviation is not a value between the lower limit deviation limiter value and the upper limit deviation limiter value (S4, N), and the deviation does not exceed 0 (S6, N), the calculated deviation E (n ) Is output (S8).

The deviation limiter 16 outputs the deviation E (n) calculated as described above to the PID regulator 17. Based on the deviation E (n) calculated by the deviation limiter 16, the PID regulator 17 calculates a torque command calculation value according to the (Expression 2) or (Expression 3) (S9).

Here, a parameter value matched with the response speed of the engine generator 4 is set in the PID regulator 17, and the amount of change per unit time of the torque command value output to the inverter 8 is limited. The motor can be controlled with the response speed close to the response speed of the engine generator 4, more specifically with the response speed of the inverter 8 slightly lower than the response speed of the engine generator 4. 9 can calculate and output a torque command calculation value that matches the responsiveness of the power output to 9 with the response speed of the engine generator 4. Therefore, the electric power output from the inverter 8 to the motor 9 does not fluctuate extremely, and the rotational speed and frequency of the engine generator 4 are stabilized.

Further, in the present embodiment, the PID parameter of the PID regulator 17 is appropriately set to limit the amount of change per unit time of the torque command value output to the inverter 8 to prevent hunting of the engine generator 4. Further, as described above, the deviation is set within a predetermined range by the deviation limiter 16, so that an extreme change in motor power expected when the deviation is large can be avoided. A synergistic effect that further stabilizes the rotational speed and frequency of the machine 4 is obtained.

Further, by limiting the deviation within a predetermined value range by the deviation limiter 16, an ordinary converter (for example, a proportional device) is used instead of the PID regulator 17 in which the specific PID parameter value is set. Even if the torque command value is calculated based on the limited deviation, since the input value is sufficiently limited, the amount of change per unit time of the torque command value output to the inverter 8 can be limited.

Therefore, the deviation limiter 16 and the PID regulator 17 may be performed independently to limit the amount of change per unit time in the torque command value output to the inverter 8, but as described above, the deviation limiter 16 and the PID It is preferable to use the regulator 17 together.
In this case, the adjustment of the PID parameter value for preventing the engine generator 4 from hunting does not need to be set to “strictly dull” the response of the inverter 8 as compared with the case where the deviation limiter 16 is not provided, and is looser. May be. That is, as in the case where there is no deviation limiter 16, the effect necessary to stabilize the rotational speed and frequency of the engine generator 4 can be obtained without bringing the response speed of the inverter 8 close to the response speed of the engine generator 4. .

The PID regulator 17 outputs the torque command calculation value to the lower limiter 18. The lower limiter 18 calculates a torque command value according to the above (Equation 4) based on the torque command calculation value calculated by the PID regulator 17 (S10).

That is, when the torque command calculation value is equal to or greater than the lower limit value (S10, Y), the torque command calculation value is set as the torque command value (S11). When the torque command calculation value is less than the lower limit value (S10, N), the lower limit value is set as the torque command value (S12). By changing the setting of the lower limiter value of (Equation 4), the motor regenerative electric energy can be arbitrarily limited.

The lower limiter 18 outputs the calculated torque command value to the inverter 8, and the control operation ends (END).

Next, the adjustment of the PID parameter in the first embodiment described above will be described with a more specific example.
The value of the PID parameter varies depending on the output and characteristics of each device. In this example, the specifications of each device are set as follows.
Capacity of motor 9: 295KW
Capacity of inverter 8: 315KW
Engine generator 4 capacity: 400KW

Also, the motor target rotational speed is determined by the point-to-point linear interpolation table shown in FIG. The setting constant α required for the speed limiter 14 to calculate and output a speed limiter command is set to +150 min-1. That is, a speed limiter command is obtained by adding 150 min-1 to the motor target rotational speed.

According to the above setting, the PID parameter (speed type) is as follows.
When the range between the lower limit value and the upper limit value in the deviation limiter 16 is adjusted to 100 min−1,
The P component is 4.000, the I component is 1.350, and the D component is 0.055.
When the range of the lower limiter value and the upper limiter value in the deviation limiter 16 is adjusted to 750 min−1,
P minutes are 2.000 I minutes and 0.900 D minutes are 0.000.

Next, a marine vessel propulsion apparatus 1a according to the second embodiment will be described with reference to FIG.
This marine vessel propulsion apparatus 1 a is a hybrid type marine vessel propulsion apparatus, and has a motor 9 and a main engine (diesel engine) 20 as drive sources for the propeller 10. The motor 9 is connected to the propeller 10 via a deceleration turning mechanism 22, and the main engine 20 is connected to the propeller 10 via a clutch 21 and a deceleration turning mechanism 22. Other configurations are the same as those of the first embodiment.

As can be understood from the description of each embodiment described above, the present invention can be widely applied to a ship propulsion apparatus having a structure for propelling a ship with an inverter-driven motor.

As described above, according to the embodiment of the present invention, the fluctuation amount of the electric power output from the inverter 8 to the motor 9 is a fluctuation amount that the generator 3 can respond to. That is, the parameter of the controller 11 that controls the inverter 8 is adjusted so that the response of the inverter 8 that outputs electric power to the motor 9 matches the response speed of the engine generator 4. The responsivity is comparable to that when the main engine diesel engine 2 drives the propeller 10. Therefore, the controller 11 does not need to perform control based on information from the engine generator 4 side, and the engine generator 4 can stabilize the rotation speed only by governor control, and the engine generator 4 causes hunting. This is definitely prevented.

Further, prior to the above control in the PID regulator 17, the deviation limiter 16 performs control so that the deviation between the motor target rotation speed and the motor rotation speed is not more than a predetermined value. An extreme change in the electric power of the motor 9 can be avoided, and a further synergistic effect of stabilizing the rotational speed and frequency of the engine generator 4 can be obtained.

DESCRIPTION OF SYMBOLS 1, 1a ... Ship propulsion apparatus 2 ... Engine 3 ... Generator 4 ... Engine generator 8 ... Inverter 9 ... Motor 11 ... Controller 14 ... Speed limiter 16 ... Deviation limiter 17 ... PID regulator 18 ... Lower limit limiter

Claims

An engine generator that generates electric power by driving a generator with an engine;
A motor for propelling the ship;
An inverter for torque controlling the motor using electric power supplied from the engine generator;
In the mechanism for outputting a torque command value to the inverter based on the deviation between the current rotation speed of the motor and the target rotation speed, the amount of change per unit time of the torque command value output to the inverter is A torque command value limiting unit for limiting the engine generator so that the response speed of the inverter does not cause hunting;
A marine vessel propulsion device comprising:
The torque command value limiting unit is a PID regulator that PID-calculates a torque command value and outputs the torque command value to the inverter, and the engine generator does not cause hunting for a change amount per unit time of the torque command value. The marine vessel propulsion apparatus according to claim 1, wherein the marine vessel propulsion apparatus is a PID regulator in which a PID parameter for limiting the response speed of the inverter is set.
2. The ship propulsion according to claim 1, wherein the torque command value limiting unit is a deviation limiter that limits a deviation between a current rotation speed of the motor and a target rotation speed within a predetermined value range. apparatus.
The torque command value limiter is
A deviation limiter for limiting the deviation between the current rotational speed of the motor and the target rotational speed within a predetermined value range;
A PID regulator that performs a PID calculation of a torque command value so as to reduce a deviation output from the deviation limiter, and outputs the torque command value to the inverter, wherein the engine generator determines the amount of change per unit time of the torque command value. A PID regulator in which a PID parameter to be limited is set so that the response speed of the inverter does not cause hunting;
The ship propulsion apparatus according to claim 1, comprising:
The ship propulsion device according to any one of claims 1 to 4, further comprising a lower limiter that provides a lower limit to the torque command value calculated by the PID regulator.
A speed limiter command is calculated by adding a preset constant to the target rotational speed of the motor, and the speed limiter command is output to the inverter to prevent over-rotation of the motor. The ship propulsion device according to any one of claims 1 to 5, wherein
A ship propulsion method for propelling a ship by supplying electric power generated by driving the engine of an engine generator that drives the generator with an engine via an inverter that torque-controls the motor. ,
A ship propulsion method, wherein a change amount per unit time of a torque command value output to the inverter is limited to a response speed of the inverter at which the engine generator does not cause hunting.
A PID parameter is set to limit the amount of change per unit time of the torque command value output by performing PID calculation to the inverter to the response speed of the inverter where the engine generator does not cause hunting. Is output to the inverter. The ship propulsion method according to claim 7.
The deviation between the current rotation speed of the motor and the target rotation speed is limited within a predetermined value range, and the torque command value is calculated so that the limited deviation becomes small, and then output to the inverter. The ship propulsion method according to claim 7, wherein a change amount per unit time of the torque command value to be limited is limited to a response speed of the inverter at which the engine generator does not cause hunting.
Limiting the deviation between the current rotational speed of the motor and the target rotational speed within a predetermined value range;
Setting a PID parameter that limits the amount of change in the torque command value to be output per unit time so that the response speed of the inverter does not cause hunting by the engine generator,
The ship propulsion method according to claim 7, wherein a torque command value obtained by performing PID calculation so that the limited deviation is reduced is output to the inverter.
The ship propulsion method according to any one of claims 7 to 10, wherein a lower limit is provided for the calculated torque command value.
A speed limiter command is calculated by adding a preset constant to the target rotational speed of the motor, and the speed limiter command is output to the inverter to prevent over-rotation of the motor. The ship propulsion method according to any one of Items 7 to 11.