JP4702521B2 - Electric propulsion device - Google Patents

Description

  The present invention relates to an electric propulsion device that drives a propeller for marine propulsion.

A conventional electric propulsion device used for driving a propeller for propulsion of a ship is disclosed in Patent Document 1, for example. The configuration of this electric propulsion device will be described with reference to FIG.
As shown in FIG. 5, electric power is supplied to the inboard load 2 and the AC motor 3 by an AC generator 1b driven by the prime mover 1a. Further, a converter 4a that converts AC power output from the AC generator 1b into DC power, an inverter 4b that converts DC power output from the converter 4a into AC power, and a capacitor 4c that smoothes the DC voltage are provided. . The inverter 4b has variable output voltage and frequency, and a fixed pitch propeller 5 for propulsion is directly connected to the AC motor 3 that controls the rotational speed of the AC motor 3, and the rotational force of the AC motor 3 is used as the propulsive force of the ship. It has been converted.

Another conventional electric propulsion device for driving a propeller for propulsion of a ship will be described with reference to FIG.
As shown in FIG. 6, electric power is supplied to the inboard load 2 and the AC motor 3 by the AC generator 1b driven by the prime mover 1a. The AC motor 3 controls the propulsive force of the ship by changing the pitch of the variable pitch propeller 6 for propulsion directly connected to the AC motor 3 for almost constant rotation.

  However, ships often encounter stormy weather while sailing. Then, a racing phenomenon occurs in which the fixed pitch propeller for propulsion is exposed on the sea surface and idles due to waves during stormy weather or the like.

  Incidentally, in the conventional electric propulsion device for driving a propeller for propulsion shown in FIG. 5 as described above, the load torque applied to the fixed pitch propeller 5 for propulsion varies abruptly due to racing. Such fluctuations in the load torque are fluctuations in the power of the AC motor 3, and therefore the fluctuations in the output of the generator 1b that supplies power. The output of the generator 1b is the output of the directly connected prime mover 1a, and there is a disadvantage that black smoke is generated when the prime mover 1a undergoes a sudden output fluctuation in a diesel engine. Further, when the power supply from the main power generation device 1 is lost, another main power generation device (not shown) is started to supply power, but until the other main power generation device supplies power, the AC motor 3 is There is also a problem that it becomes impossible to drive and navigation becomes impossible.

Further, even in the case of the conventional electric propulsion device shown in FIG. 6, the load torque applied to the propulsion variable pitch propeller 6 changes rapidly due to racing, and if the power supply from the main power generation device 1 is lost at this time, another main power generation Until the device supplies power, the AC motor 3 cannot be operated and cannot travel, so that the same phenomenon as in the conventional example of FIG. 5 occurs.
JP 11-285291 A

  The present invention has been made to cope with the above situation, and an object of the present invention is to provide an electric propulsion device that suppresses generator output fluctuations even when load fluctuations of a propulsion propeller for a ship occur during stormy weather. Another object is to provide an electric propulsion device capable of navigating even when power supply from the main power generator is lost.

  In order to achieve the object of the present invention, according to the present invention, the output power of the AC generator is converted to DC power by a converter, and the DC power is converted to AC power by an inverter and input to the AC motor. In the electric propulsion device for a ship that drives a fixed pitch propeller for propulsion with this AC motor, a charger / discharger that absorbs load power fluctuations of the AC motor, a power detector that detects load power of the AC motor, A differential circuit that outputs a differential value of the load power; a power increase determination circuit that outputs a command to discharge from the charger / discharger when the differential value exceeds a preset threshold; a chopper control circuit; and the differential value And a power reduction determination circuit that outputs a command to charge the charger / discharger when the voltage falls below a preset threshold value, and the AC generator generates a load power fluctuation of the AC motor. Which comprises suppressing output fluctuations of the machine.

  According to a second aspect of the present invention, in the electric propulsion device for a ship that supplies the output power of the AC generator to the AC motor and drives the variable pitch propeller for propulsion by the AC motor, the load electric power fluctuation of the AC motor is absorbed. A charger / discharger connected to the charger / discharger; during charging, the output power of the AC generator is converted from AC power to DC power and supplied to the charger / discharger; during discharging, the output of the charger / discharger An inverter that converts DC power to AC power, a power detector that detects load power of the AC motor, a differentiation circuit that outputs a differential value of the load power, and the differential value exceeds a preset threshold value. A power increase determination circuit and a chopper control circuit that output a command to discharge from the charger / discharger when the battery is discharged, and a command to charge the charger / discharger when the differential value falls below a preset threshold value A that power reduction determination circuit, which comprises suppressing the output variation of the AC generator to a load power variation of the AC motor.

  According to a third aspect of the present invention, in the electric propulsion apparatus according to the first aspect, a voltage detector for detecting a voltage in the ship and a command for discharging from the charger / discharger when the voltage falls below a preset threshold value. A voltage determination circuit for output, and a logical sum operation between the voltage determination circuit and the power increase determination circuit to perform a logical OR operation and output a chopper operation signal to the chopper control circuit, and to the AC motor even during a power outage It is characterized by being able to supply electric power.

  According to a fourth aspect of the present invention, in the electric propulsion apparatus according to the second aspect, a voltage detector that detects a voltage in the ship, and a command to discharge from the charger / discharger when the voltage falls below a preset threshold value. A voltage determination circuit for output, and a logical sum operation between the voltage determination circuit and the power increase determination circuit to perform a logical OR operation and output a chopper operation signal to the chopper control circuit, and to the AC motor even during a power outage It is characterized by being able to supply electric power.

  According to the present invention, even if a sudden electric power fluctuation of the propulsion motor occurs during stormy weather or the like, the charger / discharger performs charging or discharging so as to suppress the electric power fluctuation. There exists an effect which can suppress generating. Moreover, the power supply from the main power generator is lost, and by discharging the power from the charger / discharger at the time of a total power outage on the ship, the AC motor can be driven and the ship can be navigated until the power supply of the standby main power generator starts. effective.

The best mode for carrying out the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a configuration diagram of an electric propulsion apparatus according to a first embodiment of the present invention. The same components as those in the conventional example shown in FIG.

  In the electric propulsion apparatus according to the first embodiment of the present invention shown in FIG. 1, the configuration different from the conventional example shown in FIG. 5 includes a charger / discharger 20, a power detector 10, an instrument transformer 11, and an instrument current transformer. 12, a differentiation circuit 14, a power increase determination circuit 15, a power decrease determination circuit 16, and a chopper control circuit 17. The charger / discharger 20 includes a switch 21, a switch 22, a diode 23, a diode 24, a reactor 25, and a capacitor 26. Both ends of the charger / discharger 20 are connected to the input terminal of the inverter 4b, the inside of which is a switch 21, a diode 23, a reactor 25, and a switch 22 connected in series, and both ends of the capacitor 26 are connected to a reactor 25 connected in series. A diode 24 is connected to both ends of the switch 22, and a diode 24 is connected to a connection portion between the reactor 25 and the switch 22 and the other end of the switch 21.

Next, the operation of the electric propulsion apparatus according to the present embodiment will be described.
The power detector 10 inputs the voltage detected by the instrument transformer 11 and the current detected by the instrument current transformer 12 and outputs the power consumption P of the AC motor 3. The differentiating circuit 14 calculates the power change rate dP / dt. If the power reduction determination circuit 16 determines that the value is smaller than the set threshold value K ₁ (where K ₁ <0), the switch 21 is turned on, the switch 22 is turned off, and the capacitor 26 is charged. By this charging, a decrease in the output of the AC generator 1b is suppressed with respect to a decrease in the output of the AC motor 3. On the contrary, when it is determined that the threshold value K _{2 is} larger than the threshold value K ₂ set by the power increase determination circuit 15 (where K ₂ > 0), the switch 21 is turned off and a chopper operation command is output to the chopper control circuit 17. The chopper control circuit 17 repeats turning on / off of the switch 22 when a chopper operation command is input. In this way, the switch 22, the diode 24, and the reactor 25 operate as a boost chopper, and the capacitor 26 is discharged. Thereby, the increase in the output power of the AC generator 1b is suppressed with respect to the increase in the output of the AC motor 3.

  As described above, according to the electric propulsion apparatus of the present embodiment, even if a sudden load fluctuation of the propeller occurs during stormy weather or the like, the power fluctuation of the driving AC motor is detected, and the power consumption of the AC motor is increased. The charger / discharger is discharged at times, and when the power consumption of the AC motor is reduced, it is charged to suppress sudden power fluctuations of the AC generator and suppress black smoke generated by sudden changes in the output of the prime mover (diesel engine). can do.

(Second Embodiment)
FIG. 2 is a configuration diagram of an electric propulsion apparatus according to a second embodiment of the present invention. The same components as those in the first embodiment of FIG. .

  The electric propulsion apparatus according to this embodiment differs from the first embodiment of FIG. 1 in that the primary side of the inverter 7 is connected to a power line connecting the main power generator 1 and the AC motor 3 without using a converter. The secondary side is connected to both ends of the charger / discharger 20.

Next, the operation of this embodiment will be described.
The operation of the charger / discharger 20 is the same as that of the first embodiment of FIG. On the other hand, when the charger / discharger 20 is charged by the inverter 7, AC power is converted to DC power. On the other hand, when discharging from the charger / discharger 20, DC power is converted to AC power.

  Since the present embodiment is configured as described above, similarly to the first embodiment, even if a sudden load fluctuation of the propeller occurs during stormy weather, the power fluctuation of the driving AC motor is detected. When the power consumption of the AC motor is increased, the charger / discharger is discharged. When the power consumption of the AC motor is decreased, charging is performed, thereby suppressing the rapid power fluctuation of the AC generator and the output of the motor (diesel engine). An electric propulsion device that can suppress black smoke generated by a sudden change can be provided.

(Third embodiment)
FIG. 3 is a block diagram of an electric propulsion apparatus according to a third embodiment of the present invention. The same components as those of the first embodiment of FIG. .

  The electric propulsion apparatus according to the present embodiment is different from the first embodiment shown in FIG. 1 in that the circuit breaker 8 and the voltage detector 13 are provided on the input side of the converter 4a, and the voltage detector 13 detects the electric propulsion apparatus. An AC voltage is input to the voltage determination circuit 18 and an output thereof and an output of the voltage increase determination circuit 15 are input to the logical sum calculator 19.

Next, the operation of this embodiment will be described.
Voltage detector 13 outputs the detected voltage effective value V ₁ the input AC voltage of the converter 4a. Here, when the main power generation apparatus 1 is stopped due to failure and no power is supplied, and the voltage determination circuit 18 determines 0 V, the switch 21 and the circuit breaker 8 are turned off. Thereafter, if it is determined by the voltage determination circuit 18 that V ₁ is smaller than the set threshold value V _L , a voltage drop signal is output. The logical sum calculator 19 outputs a logical sum C ₁ of the voltage drop signal and the chopper operation command output from the voltage increase determination circuit 15. When the chopper control circuit 17 is a C ₁ is input to repeat the on / off switch 22. As a result, the switch 22, the diode 24, and the reactor 25 operate as a boost chopper, discharge from the capacitor 26, and supply power to the AC motor 3. Thereafter, power is supplied from the charger / discharger until another main power generator (not shown) is started and supplied with power.

  Since the present embodiment is configured as described above, the power supply from the main power generator is lost, and the AC motor can be supplied with power by discharging from the charger / discharger at the time of a total power failure in the ship. Thereby, it is possible to provide an electric propulsion device that can operate the AC motor and use it for emergency navigation until another main power generator (not shown) starts supplying power.

(Fourth embodiment)
FIG. 4 is a block diagram of an electric propulsion apparatus according to a fourth embodiment of the present invention. The same components as those of the second embodiment of FIG. .

  The electric propulsion apparatus according to the present embodiment is different from the second embodiment of FIG. 2 in that the circuit breaker 8 and the voltage detector 13 are provided on the input side of the inverter 7 and are detected by the voltage detector 13. An AC voltage is input to the voltage determination circuit 18 and an output thereof and an output of the voltage increase determination circuit 15 are input to the logical sum calculator 19.

Next, the operation of this embodiment will be described.
Since the operation of the charger / discharger 20, the circuit breaker 8, and the voltage detector 13 is the same as that of the third embodiment, the description thereof is omitted. The inverter 7 converts DC power into AC power for discharging from the charger / discharger 20.

  Since this embodiment is configured as described above, as in the third embodiment, power supply from the main power generator is lost, and power is supplied to the AC motor by discharging from the charger / discharger at the time of a total power outage on board. Is possible. Thereby, it is possible to provide an electric propulsion device that can operate the AC motor and use it for emergency navigation until another main power generator (not shown) starts supplying power.

The block diagram of the electric propulsion apparatus which is the 1st Embodiment of this invention. The block diagram of the electric propulsion apparatus which is the 2nd Embodiment of this invention. The block diagram of the electric propulsion apparatus which is the 3rd Embodiment of this invention. The block diagram of the electric propulsion apparatus which is the 4th Embodiment of this invention. The block diagram of the conventional electric propulsion apparatus. The block diagram of the other conventional electric propulsion apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Main power generator, 1a ... Prime mover, 1b ... AC generator, 2 ... Inboard load, 3 ... AC motor, 4a ... Converter, 4b ... Inverter, 4c ... Condenser, 5 ... Fixed pitch propeller for propulsion, 6 ... For propulsion Variable pitch propeller, 7 ... Inverter, 8 ... Circuit breaker, 10 ... Power detector, 11 ... Instrument transformer, 12 ... Instrument current transformer, 13 ... Voltage detector, 14 ... Differentiation circuit, 15 ... Power increase judgment Circuit: 16 ... Power reduction judgment circuit, 17 ... Chopper control circuit, 18 ... Voltage judgment circuit, 19 ... Logical sum calculator, 20 ... Charge / discharge device, 21 ... Switch, 22 ... Switch, 23 ... Diode, 24 ... Diode, 25 ... Reactor, 26 ... Capacitor.

Claims (4)

  An electric propulsion device for a ship that converts output power of an AC generator into DC power by a converter, converts the DC power to AC power by an inverter, and inputs the AC power to an AC motor, and drives the fixed pitch propeller for propulsion by the AC motor. A charger / discharger that absorbs load power fluctuations of the AC motor, a power detector that detects load power of the AC motor, a differential circuit that outputs a differential value of the load power, and the differential value is preset. A power increase determination circuit and a chopper control circuit that output a command to discharge from the charger / discharger when the threshold value is exceeded, and a command to charge the charger / discharger when the differential value falls below a preset threshold value An electric propulsion apparatus comprising: a power reduction determination circuit for outputting, and suppressing output fluctuation of the AC generator with respect to load power fluctuation of the AC motor.   In a marine electric propulsion apparatus that supplies output power of an AC generator to an AC motor and drives a variable pitch propeller for propulsion by the AC motor, a charger / discharger that absorbs load power fluctuations of the AC motor, and the charge / discharge Connected to an electric device, when charging, the output power of the AC generator is converted from AC power to DC power and supplied to the charger / discharger. When discharging, the DC power output from the charger / discharger is converted to AC power An inverter for detecting the load power of the AC motor, a differential circuit for outputting a differential value of the load power, and discharging from the charger / discharger when the differential value exceeds a preset threshold value. A power increase determination circuit and a chopper control circuit that output a command to perform, and a power decrease determination circuit that outputs a command to charge the charger / discharger when the differential value falls below a preset threshold value; Provided, electric propulsion device, characterized in that to suppress the output variation of the AC generator to a load power variation of the AC motor.   The electric propulsion device according to claim 1, wherein a voltage detector that detects a voltage in a ship, a voltage determination circuit that outputs a command to discharge from the charger / discharger when the voltage falls below a preset threshold value, and A logical sum calculation unit that performs a logical sum operation between a voltage determination circuit and the power increase determination circuit and outputs a chopper operation signal to the chopper control circuit is provided, and power can be supplied to the AC motor even in a ship power failure. Electric propulsion device. The electric propulsion apparatus according to claim 2, wherein a voltage detector that detects a voltage in a ship, a voltage determination circuit that outputs a command to discharge from the charger / discharger when the voltage falls below a preset threshold value, and A logical sum calculation unit that performs a logical sum operation between a voltage determination circuit and the power increase determination circuit and outputs a chopper operation signal to the chopper control circuit is provided, and power can be supplied to the AC motor even in a ship power failure. Electric propulsion device.

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