JP2010089550A - System stabilization system for electric propulsion ship - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly inhibit load fluctuation in a system for an electric propulsion ship and to avoid such a worst case as power interruption due to a generator trip and the like and a failure of a driving unit for the generator under an abnormal environment of the rough sea and the like. <P>SOLUTION: A system stabilization system is provided with: a motor 2 driving load equipment such as a propeller 1 and the like arranged in the electric propulsion ship; an inverter 9 converting the voltage and frequency of power supplied to the system from the generator 3 to desired ones and controlling the motor 2; a wave detector 13 detecting the height and period of the wave generated in the vicinity of the electric propulsion ship; and a system stabilization unit 10 presuming the abnormal environment such as the rough sea based on the wave height and wave period detected by the wave detector 13. When the abnormal environment is presumed, the system stabilization unit 10 imposes an operable upper speed limit on the inverter 9 and reduces the maximum load current of the motor 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a system stabilization system used for an electric propulsion ship.

In electric propulsion vessels, fluctuations in the waves (water surface) are strong due to rough seas, etc., and if a propeller, which is a load facility, appears on the water surface during navigation, load fluctuations occur due to load reduction (load loss). . In such a case, the amount of power consumed in the system suddenly changes with respect to the power supplied to the system by the generator to drive the propeller, and the balance is lost. The speed of the generator drive device is fluctuated.
In addition, FIG. 5 is a figure which shows the relationship between a water surface position and the propeller load of an electric propulsion ship.

  In particular, in a grid system in which the power generation capacity and the load consumption capacity are close to each other, when the above-described sudden and excessive load fluctuation occurs, the grid voltage and the rotational speed of the generator fluctuate significantly. In such a case, the voltage protection of the generator and the speed protection of the generator drive device are activated, and there is a possibility that a trip of the drive device or the generator, a power failure, a premises blackout, or the like may occur. In addition, when such load fluctuations frequently occur, engine failure may occur due to repeated governor adjustment.

  In order to solve such problems, conventionally, by monitoring the voltage, current, frequency, etc. of the power supply system, when these values change due to load fluctuations, etc., the generator excitation voltage is set by the generator AVR control unit. The above change was corrected by controlling the torque of the drive device by the governor control unit of the drive device, and the balance between the power generation capacity and the load power consumption and the speed of the drive device were made constant. .

However, the excitation voltage control by the generator AVR control unit and the torque control by the governor control unit of the drive device are slow in response of the control, and when the sudden and excessive load fluctuation as described above occurs, Voltage protection and generator drive speed protection may trip and trip.
Also, under abnormal circumstances such as rough seas, the load fluctuation cycle and rate of change are particularly severe, and control based on detection results such as the voltage of the power system is not sufficient, and fluctuation frequency control may cause hunting. There was also.

  The present invention has been made to solve the above-described problems, and its purpose is to appropriately suppress load fluctuations on the system even under abnormal environments such as rough seas, and to generator trips and the like. An object of the present invention is to provide an electric propulsion ship system stabilization system that can reliably avoid the worst cases such as power failure and failure of a generator drive device.

  An electric propulsion ship system stabilization system according to the present invention includes an electric motor for driving load equipment such as a propeller provided in the electric propulsion ship, and electric power supplied from the generator to the system at a desired voltage and frequency. Based on the wave height and wave period detected by the wave detector, the inverter that controls the electric motor, the wave detector that detects the height and period of the wave generated in the vicinity of the electric propulsion ship A system stabilizing device that predicts an abnormal environment such as rough sea, and the system stabilizing device imposes a limit on the upper operating speed limit for the inverter when the occurrence of the abnormal environment is predicted, The load current is reduced.

  According to this invention, in an electric propulsion ship, even under an abnormal environment such as rough seas, load fluctuations on the system can be appropriately suppressed, such as a power failure caused by a generator trip or the like, or a failure of a generator drive device. The worst case can be reliably avoided.

  In order to explain the present invention in more detail, it will be described with reference to the accompanying drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

Embodiment 1 FIG.
1 is a block diagram showing a system stabilization system for an electric propulsion ship according to Embodiment 1 of the present invention.
In FIG. 1, reference numeral 1 denotes a propeller for obtaining a propulsive force by rotating in water. That is, the propeller 1 constitutes load equipment provided in a ship (electric propulsion ship). 2 is an electric motor for rotationally driving the propeller 1, 3 is a generator for supplying predetermined AC power to the system, and 4 is a drive device (generator driving engine) for driving the generator 3. is there. Reference numeral 5 denotes a detector that detects the rotational speed of the driving device 4, and reference numeral 6 denotes a governor provided corresponding to the driving device 4. The governor 6 has a function of autonomously adjusting the rotational speed of the drive device 4.

  7 is an AVR (Automatic Voltage Regulator) control unit for controlling the excitation voltage of the generator 3, 8 is a governor control unit for controlling the governor 6, and 9 is an inverter for controlling the electric motor 2. The inverter 9 is connected to the generator 3 side with respect to the electric motor 2, converts the electric power supplied from the generator 3 side into a voltage and frequency of a desired value, and supplies the electric voltage to the electric motor 2.

  Reference numeral 10 denotes a system stabilizing device constituting the main part of the present invention. This system stabilizing device 10 is provided to stabilize a system by suppressing load fluctuations on the system, and the calculation unit 11 and the deviation counter 12 constitute a main part thereof. In addition, the system stabilizing device 10 interfaces with various devices such as an AVR control unit 7, a governor control unit 8, an inverter 9, and a wave detector 13 described later in order to collect necessary data and output reference commands. .

  FIG. 2 is a diagram for explaining the function of the wave detector, and FIG. 3 is a diagram showing the positional relationship between the propeller and the wave detector. The wave detector 13 will be specifically described with reference to FIGS.

  The wave detector 13 detects and detects the height h (hereinafter referred to as “wave height h”) and the wave period t (hereinafter referred to as “wave period t”) generated in the immediate vicinity of the ship. It has a function of outputting the result to the system stabilizing device 10. Here, FIG. 2 shows an example of a detection method by the wave detector 13. The wave detector 13 calculates the wave height h and the wave period t, for example, by actually measuring the vertical movement of the float 13a floating just outside the hull.

  The wave detector 13 is disposed at the bow side at a position for detecting the wave height h and the wave period t, for example, as shown in FIG. Generally, the propeller 1 for obtaining a propulsive force is provided on the stern side as shown in FIG. For this reason, when the electric propulsion ship having the above-described configuration is navigated, the propeller 1 is closest to the point A after a predetermined time has elapsed after the detection position of the wave detector 13 passes a certain position (point A) on the water surface. To do. That is, with the above configuration, the state of the wave received by the propeller 1 can be detected by the wave detector 13 a predetermined time before. As a matter of course, the predetermined time can be obtained based on the detection position of the wave detector 13, the distance between the propellers 1 and the speed of the ship.

  Next, based on FIG. 4, operation | movement of the system stabilization system of the electric propulsion ship which has the said structure is demonstrated. FIG. 4 is a diagram showing a control flow of the system stabilization system for the electric propulsion ship shown in FIG.

  As shown in FIG. 4, the output stabilizing rate ΔI and the frequency changing rate Δrpm are input from the inverter 9 to the system stabilizing device 10. Further, the detected wave height h and the wave period t are input from the wave detector 13. Then, the system stabilizing device 10 predicts an abnormal environment such as rough sea based on the wave height h and the wave period t input from the wave detector 13. Specifically, in the system stabilizing device 10, the deviation counter 12 calculates a deviation between the input wave height h and the wave period t, and compares the calculated deviation with a preset deviation criterion. And, when the calculated deviation exceeds the deviation standard is monitored and counted, and within a predetermined period, when the deviation exceeding the deviation standard is calculated more than the allowable number, an abnormal environment such as rough sea has occurred, That is, it is determined that an abnormal load operation has occurred due to the abnormal environment.

  When the occurrence of an abnormal environment such as rough sea is predicted, the system stabilizing device 10 outputs a speed upper limit to the inverter 9 in order to reduce the influence on the generator 3 and its driving device 4 due to load fluctuations, Immediately limit the upper speed limit. Thereby, in the electric motor 2 in which the rotational speed and the torque characteristic are proportional, the maximum load current is reduced. That is, the load fluctuation range is narrowed and the maximum fluctuation rate is lowered.

The system stabilizing device 10 may include a function of predicting an abnormal environment such as rough sea based on the output current change rate ΔI and the frequency change rate Δrpm input from the inverter 9 together with the above function. That is, the system stabilizing device 10 calculates a deviation between the input output current change rate ΔI and the frequency change rate Δrpm, and compares the calculated deviation with a preset deviation criterion. And, when the calculated deviation exceeds the deviation standard is monitored and counted, and within a predetermined period, when the deviation exceeding the deviation standard is calculated more than the allowable number, an abnormal environment such as rough sea has occurred, That is, it is determined that an abnormal load operation has occurred due to the abnormal environment.
In addition, the operation | movement with respect to the inverter 9 after estimating generation | occurrence | production of abnormal environments, such as rough sea, by the said function is the same as the above-mentioned operation | movement.

  Then, when the occurrence of an abnormal environment such as rough sea is predicted, the system stabilizing device 10 determines the voltage adjustment rate for the generator 3 based on the output current change rate ΔI and the frequency change rate Δrpm input from the inverter 9. The calculation result (voltage adjustment reference) is output to the AVR control unit 7. In the generator 3, the excitation voltage is appropriately adjusted by the operation of the AVR control unit 7 according to the reference command.

Similarly, when the occurrence of an abnormal environment such as rough sea is predicted, the system stabilizing device 10 determines the governor adjustment rate for the driving device 4 based on the output current change rate ΔI and the frequency change rate Δrpm input from the inverter 9. And the calculation result (governor adjustment reference) is output to the governor control unit 8. In the drive device 4, the governor control unit 8 is operated according to the reference command, so that the torque is appropriately adjusted.
And the voltage and frequency of a system | strain are stabilized by the said adjustment of the governor 6 and AVR by a voltage adjustment reference | standard and a governor adjustment reference | standard.

  According to Embodiment 1 of the present invention, even under an abnormal environment such as rough sea, load fluctuations on the system can be appropriately suppressed, such as a power failure caused by a generator trip or the like, or a failure of a generator drive device. The worst case can be reliably avoided.

  That is, it is possible to detect in advance the wave action that causes the load fluctuation by the water level detection circuit attached to the side surface of the hull and the like, so that the propeller 1 comes out on the water surface during navigation from the detection result. It can be determined whether or not an abnormal environment such as a rough sea occurs. For this reason, the occurrence of abnormal load conditions such as racing can be grasped in advance, and the operating speed range can be narrowed before a load change actually occurs or before a sudden load change continues and a failure occurs. Thus, the maximum load fluctuation rate can be reduced. That is, even under an abnormal environment such as rough sea, it is possible to reliably avoid a power failure due to a generator trip or the like, a failure of a generator drive device, or the like.

  In the first embodiment, the power supply system in the electric propulsion ship has been described. However, if the power supply system has the same configuration as described above, the power supply system can be applied to other industrial plants. is there.

It is a block diagram which shows the system | strain stabilization system of the electric propulsion ship in Embodiment 1 of this invention. It is a figure for demonstrating the function of a wave detector. It is a figure which shows the positional relationship of a propeller and a wave detector. It is a figure which shows the control flow of the system | strain stabilization system of the electric propulsion ship shown in FIG. It is a figure which shows the relationship between a water surface position and the propeller load of an electric propulsion ship.

Explanation of symbols

1 Propeller (load equipment)
DESCRIPTION OF SYMBOLS 2 Electric motor 3 Generator 4 Drive device 5 Detector 6 Governor 7 AVR control unit 8 Governor control unit 9 Inverter 10 System stabilizer 11 Computation part 12 Deviation counter 13 Wave detector 13a Floating

Claims (4)

An electric motor for driving load equipment such as a propeller provided in the electric propulsion ship;
An inverter for controlling the electric motor by converting the electric power supplied from the generator to the system into a desired voltage and frequency;
A wave detector for detecting the height and period of a wave generated in the vicinity of the electric propulsion ship;
Based on the wave height and wave period detected by the wave detector, a system stabilization device that predicts an abnormal environment such as rough sea,
With
The system stabilizing device imposes a limitation on an upper limit speed of operation for the inverter and reduces the maximum load current of the electric motor when an abnormal environment is predicted to occur. Stabilization system.   The system stabilization device calculates the deviation of the wave height and wave period detected by the wave detector, and if the deviation exceeding the predetermined deviation standard is calculated more than the allowable number within the predetermined period, the abnormal system is generated. The system stabilization system for an electric propulsion ship according to claim 1, wherein the system is detected. An AVR control unit that controls the excitation voltage of the generator;
A governor control unit for controlling a governor provided corresponding to the generator drive device;
Further comprising
When the occurrence of an abnormal environment is predicted, the system stabilizing device calculates a voltage adjustment rate for the generator and a governor adjustment rate for the drive device based on the change rates of the output current and frequency of the inverter. 3. The electric propulsion ship system according to claim 1 or 2, wherein the calculation result is output to the AVR control unit and the governor control unit to stabilize the voltage and frequency of the system. Stabilization system. The wave detector is installed on the bow side of the electric propulsion ship,
The system for stabilizing an electric propulsion ship according to any one of claims 1 to 3, wherein the load facility is provided on a stern side of the electric propulsion ship.

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