JP6199279B2 - Power conversion device for 2-axis electric propulsion ship - Google Patents

Description

  Embodiments described herein relate generally to a power conversion device for a two-axis electric propulsion ship.

  In an electric propulsion apparatus for a ship, the capacity of a propulsion generator that supplies power is small, and an output limiting function for protecting the propulsion generator and a torque limiting function for protecting the propulsion motor may be provided.

  For example, in a power conversion device for a two-axis electric propulsion ship that is speed-controlled based on the same speed reference, the load on the inner propulsion motor is heavy and the load on the outer propulsion motor is light during turning.

  FIG. 5 is a diagram for explaining the conventional behavior when the output is limited during turning of the propulsion motor in the two-axis electric propulsion ship. When the two-axis electric propulsion ship is traveling straight ahead, the rotational speeds n1 and n2 of the two propulsion motors M1 and M2 are driven at the rotational speed set by the target rotational speed ns until the turning start timing t1. FIG. 6 is a diagram for explaining the behavior of the biaxial electric propulsion ship according to this embodiment when the torque is limited, and shows a case where the biaxial electric propulsion ship starts turning at a constant rudder angle on the left side in the traveling direction. That is, in the two-axis electric propulsion ship, the propulsion motor M1 is an inner propulsion motor, and the propulsion motor M2 is an outer propulsion motor.

  From the turning start timing t1 to the inner torque limit start timing t2, the rotation speeds n1 and n2 of the propulsion motors M1 and M2 are driven at the rotation speed set by the target rotation speed ns.

Japanese Patent No. 5025176

  In FIG. 5, in a ship where the propulsion generator and the propulsion motor have a one-to-one electric propulsion device, the propulsion motor inside the turning is limited by the power limitation of the propulsion generator inside the turning (hereinafter referred to as the inner propulsion generator). (Hereinafter referred to as the inner propulsion motor) M1 is torque limited and the rotational speed n1 is decreased, and further, the propulsion motor outside the turning (hereinafter referred to as the outer propulsion motor) M2 continues to limit the speed with respect to the target rotational speed. Then, the speed deviation (rotational speed deviation) becomes large, and after the turn end timing t3, it takes time to return from the torque limit, and there is a problem that the motion performance of the ship is hindered.

  The present invention has been made in order to solve the above-described problems. The torque limit detection signals of the respective propulsion motors that drive the two-axis electric propulsion ship are mutually transferred, and one of the propulsion motors becomes the torque limit by turning. In response to this signal, the target speed reference of the other propulsion motor is lowered, and the load on the other propulsion motor is reduced, thereby reducing the speed deviation between the propulsion motors, and at the end of the turn, the target speed is quickly reached. An object of the present invention is to provide a power conversion device for a two-axis electric propulsion ship that can be returned to

  To achieve the above object, a power conversion device for a two-axis electric propulsion ship according to the present invention is a two-axis electric propulsion ship having at least two propulsion motors and a power conversion device for driving the propulsion motors, respectively. Two control means for controlling two power converters that drive the two propulsion motors are provided, the propulsion motors being provided on the left and right of the propulsion shaft of the two-axis electric propulsion ship, and of the propulsion motor A rotating shaft is arranged in parallel with the propulsion shaft, and the two control means each include torque limiting means for driving and controlling the rotating shaft of the corresponding propulsion motor, and the torque output by the torque limiting means of one propulsion motor When the limit detection signal is transmitted to the control unit of the other propulsion motor and the control unit of the other propulsion motor receives the torque limit detection signal output from the torque limit unit of the one propulsion motor Characterized by lowering the speed reference of the other propulsion motor.

  According to the present invention, by applying the power conversion device according to the present invention to a biaxial electric propulsion ship, the biaxial electric propulsion ship can return to the target speed at an early stage when the turn is completed.

The electric power system diagram of the 2 axis | shaft electric propulsion ship which concerns on a present Example. The block diagram of the control part of the 2-axis electric propulsion ship which concerns on a present Example. The figure explaining the behavior at the time of the output restriction at the time of turning of the propulsion motor which propels the 2-axis electric propulsion ship concerning this example. The figure explaining the relationship between the propulsion motor M1 and the M2 torque limit detection signal or the propulsion motor M2 and the M1 limit detection signal. The figure explaining the conventional behavior at the time of the output limitation at the time of turning of the propulsion motor in a 2-axis electric propulsion ship. The figure explaining the behavior at the time of the torque limitation of the 2-axis electric propulsion ship which concerns on a present Example.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a power system diagram of a two-axis electric propulsion ship according to the present embodiment. The AC power generated by the propulsion generators G1 to G3 is supplied to the BUS 80 via the circuit breakers 60 to 62 and the disconnectors 50 to 52. The AC power supplied to the BUS 80 is supplied to the primary side of the transformers 30 and 31 via the circuit breakers 40 and 41. Low-voltage power consisting of secondary low-voltage (for example, AC 100V) transformed by the transformers 30 and 31 is supplied to the inverter units 20 and 21.

  The inverter units 20 and 21 are configured to include a converter (not shown) and an inverter (not shown). The converter converts low-voltage AC power supplied from the transformers 30 and 31 into DC power. The inverter converts the DC power converted by the converter into AC power necessary for the operation of the propulsion motors M1 and M2. Note that the reference numerals 10 to 11 of the propulsion motors M1 to M2 and the reference numerals 70 to 72 of the propulsion generators G1 to G3 are easy to distinguish without being provided, and are omitted unless particularly described. It is.

  The propulsion motors M1 and M2 are arranged on the left and right of the propulsion direction (propulsion shaft) of the two-axis electric propulsion ship, and the rotation shaft of the propulsion motor is arranged in parallel with the propulsion shaft.

  The control unit 90 controls the operation of the inverter units 20 and 21 including the converter and inverter described above. The inverter and converter are composed of a plurality of switching elements. Therefore, the control unit 90 controls the driving of the propulsion motors M1 and M2 described above by controlling the gates of these switching elements.

  The drive control not only starts and stops the propulsion motors M1 and M2, but also controls the rotational speed and torque of the propulsion motors M1 and M2.

  FIG. 2 is a block diagram of the control unit 90 of the two-axis electric propulsion ship according to the present embodiment. The control unit 90 does not include the inverter units 20 and 21 and the propulsion motors M1 and M2. The control unit 90 includes an M1 control unit 90a that controls the propulsion motor M1 and an M2 control unit 90b that controls the propulsion motor M2. Since the M1 control unit 90a and the M2 control unit 90b are configured similarly, the configuration of the M1 control unit 90a will be described below.

  The M1 control unit 90a includes target rotation speed setting means 100, torque limit rotation speed reduction value setting means 101, M1 motor power detection means (abbreviation for M1 propulsion motor motor power detection means) 102, G1 generator power detection means (G1). (Abbreviation of propulsion generator power detection means) 103, output limit value setting means 104, rate processing means 107, speed control means 111, torque limit means 113, current limit means 114, speed detection means 115 of the propulsion motor M1, etc. Each means of setting / processing / limitation, switching means, and arithmetic means such as addition / subtraction / division are provided. As described above, the configuration of the M2 control unit 90b is the same as the configuration of the M1 control unit 90a.

  Hereinafter, when the two-axis electric propulsion ship turns to the left in the traveling direction, the propulsion motor M1 is subjected to torque limitation by the torque limiting unit 113, and propulsion is performed by the M1 torque limit detection signal output from the torque limiting unit 113 at that time. An operation in which the rotation speed and torque of the electric motor M2 are controlled by the M2 control unit 90b will be described.

  The target rotational speed setting means 100 sets the target rotational speed of the propulsion motor M1, and its output is connected to one input terminal a of the switching means 105. Further, the torque limit rotation speed reduction value setting means 101 sets the torque limit rotation speed reduction value of the propulsion motor M1, and its output is connected to the other input terminal b of the switching means 105. The control terminal c of the switching means 105 is connected to the torque limiting means 133 of the propulsion motor M2, and is controlled by an M2 torque limit detection signal output therefrom. Normally, the output of the target rotational speed setting means 100 connected to the input terminal a of the switching means 105 is selected.

  For example, when the torque limiting means 113 of the propulsion motor M1 limits the torque of the propulsion motor M1 by turning the biaxial electric propulsion ship to the left in the traveling direction, the M1 torque limit detection signal 113a is output from the M2 control unit 90b. Sent to.

  The transmitted M1 torque limit detection signal 113a is input to the control terminal c of the switching unit 125 of the M2 control unit 90b, and the output of the torque limit rotational speed reduction value setting unit 121 connected to the input terminal b of the switching unit 125 is output. Selected.

  The output terminal d of the switching unit 125 is connected to the rate processing unit 127. The rate processing means 127 performs speed rate processing based on the rotation speed set by the target rotation speed setting means connected to the input terminal a of the switching means 125. The processing result of the rate processing means 127 is input to the subtraction means 129.

  The subtracting means 129 subtracts the speed of the propulsion motor M2 from the speed set by the rate processing means 127. The subtraction output of the subtraction unit 129 is input to the speed control unit 131. As a result, the speed control means 131 performs speed control based on the speed set by the rate processing means 127 and the differential speed between the propulsion motor M2. The power of the propulsion generator G2 detected by the propulsion generator power detection means 123 and the output power of the propulsion generator G2 set by the output limit value setting means 124 for setting the output of the propulsion generator G2 are output power. The comparison is performed by the comparison unit 128, and the speed setting by the speed control unit 131 is limited based on the comparison result. This is because, if the speed setting or the torque setting described later is performed regardless of the power generation capacity of the propulsion generator G2, it causes a failure of the propulsion generator G2, and thus prevents the failure.

  Based on the speed set by the speed control means 131. Torque for driving the propulsion motor M2 is generated, but the torque is also limited by the torque limiting means 133. This is because, if the driving torque is increased beyond the driving capability (driving torque) of the propulsion motor M2, it will cause a failure of the propulsion motor M2, so that the failure is prevented.

  The current control unit 134 controls the current supplied to the inverter unit 21. For example, when a short circuit failure of the switching element that constitutes the inverter unit 21 occurs in the inverter unit 21, the current may flow through the inverter unit 21 in excess of the allowable current. In such a case, the current control means 134 can limit the current value flowing into the inverter unit.

  As described above, the inverter unit 20 includes a converter and an inverter. The converter converts AC power into DC power. The inverter converts the DC power converted by the converter into AC power suitable for the load. Here, since propulsion motor M1 corresponds as a load, it is converted into AC power (for example, AC three-phase power) for driving propulsion motor M1.

  The propulsion motor M1 is driven by the AC power generated by the inverter unit 20 described above.

  The speed detection means 115 detects the rotational speed of the propulsion motor M1. The detected rotation speed is notified to the deceleration means 109 and the torque limit value calculation means 112.

  The propulsion motor M2 is driven and controlled by the M2 control unit 90b in the same manner as the propulsion motor M1. For example, when the torque limiting unit 133 of the propulsion motor M2 limits the torque of the propulsion motor M2 by turning the two-axis electric propulsion ship to the right in the traveling direction, the M2 torque limit detection signal 113a is output from the M1 control unit 90b. Sent to.

  The transmitted M2 torque limit detection signal 133a is input to the control terminal c of the switching unit 105 of the M1 control unit 90a, and the output of the torque limit rotation speed reduction value setting unit 101 connected to the input terminal b of the switching unit 105 is output. Selected.

  Hereinafter, the operation of each unit when the M1 control unit 90a and the M2 control unit 90b related to the operation when the two-axis electric propulsion ship turns to the left in the traveling direction will be described.

  Next, an example of a control method when the output of the propulsion motors M1 and M2 and the corresponding propulsion generators G1 and G2 described above is limited by the controller 90 will be described.

1. Regarding output restriction (1) The rotating shafts of the propulsion motors M1 and M2 are independently controlled.

(2) The output restriction control is based on the operation of two propulsion motors (here, M1 and M2),
Each axis shall be performed equally.

(3) From the operating conditions of the propulsion generator (here G1 and G2), the propulsion generator parallel operation coefficient, and the output limit coefficient, the “output limit target value”, “output limit start value”, and “output limit release value” are calculate. These values can be adjusted by setting values.

(4) When the propulsion generator output reaches the “output limit start value” level, “output limiting” is displayed and the propulsion motor is set so that the propulsion generator output is equal to or less than the “output limit target value”. Limit the output (torque limit).

(5) When the propulsion generator output drops to the “output limit release value” level, the “output limiting” indicator lamp is turned off and the propulsion motor output limit (torque limit) is released.

(6) The output reduction value is the difference between the current propulsion generator output (detected value) and the output limit target value (set value), and is converted into a value that is reduced from the motor output for one axis.

(7) The torque limit value is calculated from the electric power (calculated value) obtained by subtracting the output reduction value from the current motor output (calculated value) and the propulsion motor rotation speed (detected value).

2. Output limit control formula (1) Output limit target value [kw] = propulsion generator rated output [kw] x propulsion generator operation number [units] ÷ γ x α
(2) Output limit start value [kw] = Propulsion generator rated output [kw] × Propulsion generator operation number [unit] ÷ γ × θ
(3) Output limit release value [kw] = propulsion generator rated output [kw] x number of propulsion generators operated [unit] ÷ γ x β
α: Output limit target value coefficient [kw] (Adjustable range: 1.00 to 0.80)
θ: Output limit start value coefficient [kw] (Adjustable range: 1.00 to 0.80)
β: Output limit release value coefficient [kw] (Adjustable range: 1.00 to 0.80)
γ: Propulsion generator parallel operation coefficient [kw] (Adjustable range: 1.00 to 1.15)
Output reduction value [%] = (Propulsion generator output (AI) [kw]-Output limit target value [kw]) / Number of motors operated 2 [units] / Motor rated output 1800 [kw] ≥ 0 [%]
Propulsion generator output (AI): Calculated from the propulsion generator operation mode (1G, 2G, 3G, 1G + 2G) and the detected value (AI) of the propulsion generator output.
Torque limit value (IQ_LMT_EXT) [%] = (Motor output (calculated value) [%]-Output reduction value [%])
÷ Motor speed (SP_F_OUT) [%] × 94.2 [%] ≦ 100 [%]
That is, the torque limit value 112a (or 132a) is obtained by subtracting the output reduction value 106a (or 126a) from the motor output 102a (or 122a) and the motor output 102b (or 122b) by the motor speed 115a (or 135a). It is obtained by multiplying the value obtained by dividing by 94.2.
Motor output (calculated value) [%]: Torque reference (T_R_OUT) [%] x Motor speed (SP_F_OUT) [%] ÷ 94.2 [%] ≤ 100 [%]
Torque limit rate: The aperture (at the start of output limit) is instantaneous, and the return (after the output limit is released) is 1 [% / S] rate. After canceling the output limit, return the torque limit value to 100 [%].

  FIG. 3 is a diagram for explaining the behavior when the output is limited during turning of the propulsion motor that propels the two-axis electric propulsion ship according to the present embodiment.

  When the two-axis electric propulsion ship is traveling straight ahead, the two-axis electric propulsion ship has a turning start timing at the rotation speeds n1 and n2 of the two propulsion motors M1 and M2 set at the target rotation speed ns. Drive to t1. Here, when the turning is started to the left in the traveling direction shown in FIG. 6, the propulsion motor M1 is an inner propulsion motor and the propulsion motor M2 is an outer propulsion motor.

  From the turning start timing t1 to the inner torque limit start timing t2, the rotation speed n1 of the inner propulsion motor M1 (hereinafter referred to as the inner rotation speed n1) and the rotation speed n2 of the outer propulsion motor M2 (hereinafter referred to as the outer rotation speed n2). Is driven at the rotation speed set at the target rotation speed ns. On the other hand, as described above, the torque of the inner propulsion motor becomes heavier than the load of the outer propulsion motor with turning. Accordingly, the torque T1 of the inner propulsion motor (hereinafter referred to as the inner torque T1) is larger than the torque T2 of the outer propulsion motor (hereinafter referred to as the outer torque T2), and reaches the torque limit. If the torque becomes infinitely large, it will cause a failure of the inner propulsion motor M1, so that torque limitation is required.

  After the inner torque limit start timing t2, the outer target rotational speed ns is lowered to the inner torque limit release in response to the inner torque limit. In FIG. 2, the M1 torque limit detection signal 113a output from the torque limiting means 113 on the propulsion motor M1 side is connected to the control terminal c of the switching means 125 on the propulsion motor M2 side in FIG. This is performed by switching from the input terminal a to the input terminal b of the switching means 125 on the propulsion motor M2 side by the detection signal 113a. The input signal b is connected to the output of the torque limit rotational speed reduction value setting means 121. In this embodiment, the rotational speed n2 of the outer propulsion motor M2 (hereinafter referred to as the outer rotational speed n2) is reduced. However, at this time, it is gradually reduced so as not to be regenerative. In this way, when the outer rotational speed n2 decreases until the inner torque limit is released, the inner rotational speed n1 and the outer rotational speed n2 become the same rotational speed.

  At the inner torque limit release timing t3 at which the inner rotation speed n1 and the outer rotation speed n2 are the same, the process of returning the outer target rotation speed is performed because the inner torque limit is released. Further, with the release of the inner torque limit, the inner rotational speed n1 attempts to return to the target rotational speed ns. As a result, the inner rotation speed n1 and the outer rotation speed n2 return to the target rotation speed ns by the turn end timing.

  Note that, from the inner torque limit release timing t3 to the turning end timing t4, the inner torque T1 decreases with the torque limit release process, and the outer torque T2 increases toward the inner torque T1.

  After the turn end timing t4, the two-axis propulsion ship goes straight, and the inner rotational speed n1 and the outer rotational speed n2 are driven at the rotational speed set by the target rotational speed ns. Similarly, the inner torque T1 and the outer torque T2 returns to the set torque reference.

  FIG. 4 is a diagram for explaining the relationship between the propulsion motor M1 and the M2 torque limit detection signal or the propulsion motor M2 and the M1 limit detection signal.

  In the embodiment described above, the case where the two-axis electric propulsion ship having two propulsion motors M1 and M2 turns to the left in the traveling direction shown in FIG. 6 is described as an example. Since the propulsion motor M2 is an inner propulsion motor, torque limitation is started at the inner torque limitation start timing t2 in FIG. In this case, the M2 torque limit detection signal output from the torque limiter 133 of the M2 controller 90b is input to the control terminal c of the switching unit 125 of the M1 controller 90a, and the torque limit rotational speed reduction value setting of the propulsion motor M1 is set. The output of the means is selected (corresponding to the case where the turning inner side T1 and the turning outer side T2 shown in FIG. 3 are interchanged). In this case, the torque T1 and the outer rotational speed n1 of the outer propulsion motor are reduced. The case where the two-axis electric propulsion ship turns to the right in the traveling direction corresponds to the case where the inner propulsion motor is M2 and the outer propulsion motor 1 is M1 in the description of FIG. 3 described above.

  According to the present embodiment described above, since the rotation speeds of the inner rotation speed n1 and the outer rotation speed n2 return to the target rotation speed ns at the end of the turn, conventionally, the inner rotation speed n1 and the outer rotation speed n2 at the end of the turn. Since there is no rotation speed deviation (see FIG. 5) that occurred during the period, it is possible to solve the problem “it takes time to recover from torque limitation due to the end of turning and hinders the motion performance of the ship”. A power conversion device for a two-axis electric propulsion ship can be provided.

10, 11 Propulsion motor 20, 21 Inverter unit 30, 31 Transformer 40, 41, 60-62 Breaker 50-52 Disconnector 70-72 Propulsion generator 90 Control unit 90a M1 control unit 90b M2 control unit 100, 120 Target rotation Number setting means 101, 121 Torque limit rotational speed "reduction value setting means 102, 122 Propulsion motor power detection means 103, 123 Propulsion generator power detection means 104, 124 Output limit value setting means 105, 125 Switching means 107, 127 Rate processing Means 108, 128 Output power comparison means 109, 129 Subtraction means 111, 131 Speed control means 113, 133 Torque limiting means 114, 134 Current control means 115, 135 Speed detection means

Claims (4)

A two-shaft electric propulsion ship having at least two propulsion motors and a power converter for driving the propulsion motors,
Comprising two control means for controlling two power converters for driving the two propulsion motors;
The propulsion motor is arranged on the left and right of the propulsion shaft of the two-axis electric propulsion ship, and the rotation shaft of the propulsion motor is arranged in parallel with the propulsion shaft,
Each of the two control means includes torque limit means for driving and controlling the rotation shaft of the corresponding propulsion motor, and the torque limit detection signal output from the torque limit means of one propulsion motor is used as the control means for the other propulsion motor. And when the control means of the other propulsion motor receives the torque limit detection signal output by the torque limit means of the one propulsion motor, the speed reference of the other propulsion motor is lowered. A power converter for a 2-axis electric propulsion ship. The control means of the other propulsion motor is
2. The speed reference is gradually reduced so that regenerative operation does not occur when a torque limit detection signal detected by the one propulsion motor is received and the speed reference of the other propulsion motor is lowered. Power conversion device for 2-axis electric propulsion ship. The control means of the other propulsion motor is further
3. The electric power of the two-shaft electric propulsion ship according to claim 2, wherein when the torque limit detection signal detected by the one propulsion motor is released, the speed reference of the other propulsion motor is returned to the target rotational speed. Conversion device.   The torque limiting means of the one propulsion motor is a torque limit for the inner propulsion motor that is inside during turning, and the torque limiting means of the other propulsion motor is a torque limit for the outer propulsion motor that is outside during turning. The power conversion device for a two-axis electric propulsion ship according to any one of claims 1 to 3, wherein the power conversion device is provided.

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