Motor drive systems, marine propulsion systems and ships

Abstract

To reduce the number of parts in the motor drive system. [Solution] The ship's propulsion system comprises an electric motor and a motor drive device that drives the electric motor. The motor drive device has a power input terminal and a ground terminal connected to a ground line, and comprises a drive circuit that supplies power to the electric motor, an electrical resistance element, and a connection device. The connection device performs a first connection pattern in which the power input terminal is electrically connected to the power line via the electrical resistance element, and a second connection pattern in which the power input terminal is electrically connected to the ground line via the electrical resistance element.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a motor drive device, a ship propulsion machine, and a ship.

Background Art

[0002] A ship propulsion machine using an electric motor as a drive source is known. Such a ship propulsion machine includes an electric motor and a motor drive device that drives the electric motor. For example, a motor drive device provided in an electric tool or the like has a drive circuit (for example, an inverter circuit) that supplies power to the motor and various electrical resistance elements (shunt resistors, protective resistors) (for example, see Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is room for reducing the number of parts in conventional ship propulsion machines and motor drive devices.

[0005] This specification discloses a technology capable of solving the above-described problems.

Means for Solving the Problems

[0006] The technology disclosed in this specification can be realized, for example, in the following forms.

[0007] (1) A ship propulsion system disclosed herein comprises an electric motor and a motor drive device for driving the electric motor, wherein the motor drive device has a power input terminal and a ground terminal connected to a ground line, and includes a drive circuit for supplying power to the electric motor, an electrical resistance element, and a connection device that performs a first connection pattern in which the power input terminal is electrically connected to a power line via the electrical resistance element, and a second connection pattern in which the power input terminal is electrically connected to the ground line via the electrical resistance element.

[0008] The first connection pattern of the connection device causes the electrical resistance element to function as, for example, a pre-charge resistor, and the second connection pattern causes the electrical resistance element to function as, for example, a discharge resistor. This configuration, in which common electrical resistance elements are used for different functions, reduces the number of parts in the motor drive unit.

[0009] (2) In the above-mentioned ship propulsion machine, the connection device may be configured to include a first switch element having one end electrically connected to the power line and the other end electrically connected to the power input terminal via the electrical resistance element, and a second switch element having one end electrically connected to the ground line and the other end electrically connected to the power input terminal via the electrical resistance element. In this configuration, the first switch element and the second switch element can independently switch the first connection pattern on and off and the second connection pattern on and off.

[0010] (3) In the above-mentioned ship propulsion system, the motor drive device may further include a third switch element, one end of which is electrically connected to the power line and the other end of which is electrically connected to the power input terminal without passing through the electrical resistance element. The third switch element can switch the power supply from the power line to the drive circuit on and off independently of the connection pattern of the connection device.

[0011] (4) The above-mentioned ship propulsion system may further include a controller, and the controller may be configured to set the connection device to the first connection pattern, provided that it has received an instruction to start driving the electric motor. In this configuration, the first connection pattern suppresses the generation of inrush current to the electric motor when the electric motor starts driving.

[0012] (5) In the above-mentioned ship propulsion system, the controller may be configured to release the connection according to the first connection pattern after a first reference time has elapsed from the time the connection device is set to the first connection pattern. In this configuration, releasing the connection according to the first connection pattern suppresses power loss in the electrical resistance element.

[0013] (6) In the above-described ship propulsion system, the motor drive device may further include a third switch element having one end electrically connected to the power line and the other end electrically connected to the power input terminal without passing through the electrical resistance element, and the controller may be configured to close the third switch element from an open state after a second reference time has elapsed from the time the connection device is set to the first connection pattern. In this configuration, power can be supplied to the electric motor while suppressing the generation of inrush current to the drive circuit when the electric motor starts to drive.

[0014] (7) The above-mentioned ship propulsion system may further include a controller, and the controller may be configured to set the connection device to the second connection pattern, provided that it has received an instruction to stop the operation of the electric motor. In this configuration, the second connection pattern discharges the charge accumulated in the drive circuit.

[0015] (8) In the above-mentioned ship propulsion system, the controller may be configured to release the connection according to the second connection pattern after a third reference time has elapsed from the time the connection device is set to the second connection pattern. In this configuration, releasing the connection according to the second connection pattern suppresses leakage current from the drive circuit.

[0016] (9) In the above-mentioned ship propulsion system, the connection device has a first electrical switch element for setting and releasing the first connection pattern, and the first electrical switch element, the electrical resistance element, and the drive circuit may be mounted on the same circuit board. This configuration reduces the number of parts.

[0017] (10) In the above-mentioned ship propulsion system, the connection device may further include a second electrical switch element for setting and releasing the second connection pattern, and the circuit board may further have the second electrical switch element mounted on it. This configuration reduces the number of parts.

[0018] (11) In the above-described ship propulsion system, the motor drive device may further include a third switch element, one end of which is electrically connected to the power line and the other end of which is electrically connected to the power input terminal without passing through the electrical resistance element, and the circuit board may further have the third switch element mounted on it. This configuration reduces the number of parts.

[0019] (12) A motor drive device disclosed herein is a motor drive device for driving an electric motor, comprising: a drive circuit that supplies power to the electric motor, having a power input terminal and a ground terminal connected to a ground line; an electrical resistance element; and a connection device that performs a first connection pattern in which the power input terminal is electrically connected to a power line via the electrical resistance element, and a second connection pattern in which the power input terminal is electrically connected to the ground line via the electrical resistance element. With this motor drive device, the number of parts in a ship's propulsion system is reduced because the electrical resistance element can be shared and used for different functions.

[0020] Furthermore, the technologies disclosed herein can be implemented in various forms, for example, as a motor drive unit, a ship propulsion system equipped with a motor drive unit, a ship control system equipped with a ship propulsion system, a ship equipped with a ship propulsion system, and so on. [Effects of the Invention]

[0021] According to the technology disclosed by this specification, since the electric resistance elements can be shared and utilized in different functions, the number of parts of the ship propulsion machine is reduced.

Brief Description of the Drawings

[0022] [Figure 1] Perspective view schematically showing the configuration of the ship of the embodiment [Figure 2] Side view showing the configuration of the electric propulsion machine [Figure 3] Schematic diagram showing the configuration of the drive unit [Figure 4] Block diagram showing the configuration of the ship control system in the ship [Figure 5] Block diagram showing the internal configuration of the MCU [Figure 6] Flowchart showing the flow of the switching control process [Figure 7] Simplified diagram showing the switching pattern of the connection device

Modes for Carrying Out the Invention

[0023] FIG. 1 is a perspective view schematically showing the configuration of a ship 10 of the present embodiment. In FIG. 1 and other drawings described later, arrows indicating respective directions based on the position of the ship 10 may be shown. Specifically, in each figure, arrows indicating FRONT (front), REAR (rear), LEFT (left), RIGHT (right), UPPER (upper), and LOWER (lower) may be shown. The front-rear direction, the left-right direction, and the up-down direction (vertical direction) are directions orthogonal to each other.

[0024] As shown in FIG. 1, the ship 10 includes a hull 200 and an electric propulsion machine 100. The electric propulsion machine 100 is an example of a ship propulsion machine.

[0025] The hull 200 is a part of the ship 10 where an operator (crew) boards. The hull 200 has a hull main body portion 210, a cockpit 220, and a steering device 230.

[0026] A living space 212 is formed in the main hull section 210. The cockpit 220 is located in the living space 212. The hull 200 further includes a partition wall 214 and a transom 216. The partition wall 214 demarcates the rear side of the living space 212. The transom 216 is located at the rear end of the hull 200. In the longitudinal direction, a space 215 exists between the transom 216 and the partition wall 214.

[0027] The control device 230 is a device for steering the ship. The control device 230 is installed near the cockpit 220. The control device 230 includes a steering wheel 232, a shift / throttle lever 240, a joystick unit 250, a display device 260, and an input device 270.

[0028] The steering wheel 232 is an operating device for steering the vessel 10. The shift / throttle lever 240 is an operating device for shifting gears and changing the thrust of the vessel 10. The joystick unit 250 is an operating device for steering, shifting gears, and changing the thrust of the vessel 10. The display device 260 is, for example, a liquid crystal display that displays various images related to the vessel 10 (such as operation images). The input device 270 is a button for changing the steering mode, for example. The input device 270 includes an LED (Light-emitting Diode).

[0029] Figure 2 is a side view showing the configuration of the electric propulsion system 100. The electric propulsion system 100 is a device that generates thrust to propel the ship 10. The electric propulsion system 100 is an electric propulsion system driven by an electric motor 134. The electric propulsion system 100 in this embodiment is an outboard motor. In the following, unless otherwise specified, the electric propulsion system 100 in the reference position will be described. The reference position is the position of the electric propulsion system 100 when the ship 10 is underway (the position shown in Figures 1 and 3), and is the position in which the propeller rotation axis L of the propeller 132, which will be described later, extends in the longitudinal direction. The longitudinal, lateral, and vertical directions are each determined based on the electric propulsion system 100 in the reference position.

[0030] The electric propulsion system 100 is mounted on the transom 216 located at the rear (stern) of the hull 200 (see Figure 1). The electric propulsion system 100 comprises a propulsion unit 101 and a suspension system 102.

[0031] The thruster body 101 includes a cowl 110, a middle housing 150, a lower housing 120, a duct 122, and a drive unit 130.

[0032] The cowl 110 is located on top of the electric propulsion system 100. The cowl 110 is a cover that houses various wiring and other components.

[0033] The middle housing 150 is located below the cowl 110 of the electric propulsion system 100. The middle housing 150 is a cover that houses the steering device 152, SCU 154, and various wiring, which will be described later.

[0034] The lower housing 120 is located below the middle housing 150 in the electric propulsion system 100. The lower housing 120 is a cover that houses the MCU 139 (described later), various wiring, etc. The lower housing 120 is rotatably mounted to the middle housing 150 around an axis along the vertical direction. Note that the lower housing 120 may be positioned lower than the water surface W in the reference posture (see Figure 2).

[0035] The duct 122 is located below the lower housing 120 of the electric propulsion system 100. The duct 122 is a tubular body extending in the longitudinal direction. In the reference posture, the duct 122 is positioned lower than the water surface W (see Figure 2). The drive unit 130 is located radially inside the duct 122. A stator fin 133 and a bearing 135 are provided radially inside the duct 122 (see Figure 2). The bearing 135 supports the propeller 132, described later, so that it can rotate around the propeller rotation axis L. The stator fin 133 has multiple (e.g., three) fins. The multiple fins are arranged radially around the bearing 135. The multiple fins are arranged at equal intervals around the propeller rotation axis L. The multiple fins are fixed to the duct 122. Multiple fins are positioned behind the propeller 132, protruding rearward from the duct 122 (see Figures 1 and 2).

[0036] Figure 3 is a schematic diagram showing the configuration of the drive unit 130. The drive unit 130 generates thrust to propel the ship 10. The drive unit 130 includes a propeller 132 and an electric motor 134.

[0037] The propeller 132 is a rotating body having multiple blades. The propeller 132 generates thrust by rotating. The propeller 132 is located radially inward of the duct 122. The propeller 132 is rotatable around a horizontal propeller rotation axis L. The propeller rotation axis L is parallel to the central axis of the duct 122. The propeller 132 is completely enclosed by the duct 122.

[0038] The electric motor 134 rotates the propeller 132. The electric motor 134 includes a rotor 136 and a stator 138.

[0039] The rotor 136 is a tubular body extending in the longitudinal direction. The rotor 136 is rotatably supported relative to the duct 122. The rotor 136 rotates around the propeller rotation axis L relative to the stator 138. The propeller 132 is positioned radially inward of the rotor 136. The propeller 132 is fixed to the rotor 136. The propeller 132 rotates together with the rotor 136. The rotor 136 includes a plurality of permanent magnets 140. In Figure 5, only one of the plurality of permanent magnets 140 is referenced, and the reference numerals for the other permanent magnets 140 are omitted. The plurality of permanent magnets 140 are arranged along the circumferential direction of the rotor 136.

[0040] The stator 138 is a tubular body extending in the front-rear direction. The stator 138 is located radially outward from the rotor 136. The stator 138 is located on the same axis as the rotor 136. The stator 138 is fixed to the duct 122. The stator 138 includes a plurality of coils 142. In Figure 5, only one of the coils 142 is referenced, and the reference numerals for the other coils 142 are omitted. The plurality of coils 142 are arranged along the circumferential direction of the stator 138.

[0041] When multiple coils 142 are energized, an electromagnetic force is generated that rotates the rotor 136. With this configuration, the propeller 132 generates forward thrust when the rotor 136 of the electric motor 134 rotates in the forward direction, and backward thrust when the rotor 136 of the electric motor 134 rotates in the reverse direction.

[0042] The suspension device 102 is a device that suspends the propulsion unit 101 from the hull 200. The suspension device 102 rotates the propulsion unit 101 around the tilt axis At (see Figure 2). This enables a tilt operation that rotates the propulsion unit 101 vertically relative to the hull 200.

[0043] Figure 4 is a block diagram showing the internal configuration of the ship control system 10S in the ship 10. Each component of the ship control system 10S is connected to each other in a communicative manner, for example, by CLP (Command Line Processor) communication. As shown in Figure 4, the hull 200 has a BCU 300, a GPS 310, a battery 320, and a display control device 262.

[0044] The Boat Control Unit (BCU) 300 controls the overall operation of the vessel 10 based on signals transmitted from each of its components, for example. The BCU 300 includes, for example, a CPU, a multi-core CPU, and programmable devices (such as a Field Programmable Gate Array (FPGA) and a Programmable Logic Device (PLD)).

[0045] The GPS (Global Positioning System) 310 is a device that determines the current position of the ship 10 using signals received from satellites. The battery 320 is an energy storage device. The battery 320 supplies power to the electric motor 134 and the input device 270, which will be described later. The display control device 262 controls the display of the display device 260.

[0046] The electric propulsion system 100 includes the aforementioned electric motor 134, steering device 152, MCU 139, and SCU 154.

[0047] The steering device 152 is a device that controls the rudder angle of the vessel 10. The steering device 152 is housed in the middle housing 150. The steering device 152 includes, for example, an electric motor for steering (not shown) and a steering shaft (not shown) extending in the vertical direction. When the rudder angle is changed by the steering device 152, for example, the electric motor rotates the steering shaft. As the steering shaft rotates, the lower housing 120 connected to the steering shaft and the drive unit 130 connected to the lower housing 120 rotate around an axis along the vertical direction. This changes the rudder angle of the vessel 10.

[0048] The MCU (Motor Control Unit) 139 drives the electric motor 134. The MCU 139 is housed in the lower housing 120. The MCU 139 is an example of a motor drive device.

[0049] The Steering Control Unit (SCU) 154 controls the operation of the steering device 152. The SCU 154 includes, for example, a CPU, a multi-core CPU, and programmable devices (such as a Field Programmable Gate Array (FPGA) or Programmable Logic Device (PLD)). The SCU 154 is housed in a middle housing 150.

[0050] Figure 5 is a block diagram showing the internal configuration of the MCU139. The MCU139 includes a circuit board 162, an inverter circuit 164, an electrical resistance element 166, a power relay 168, a connection device 170, and a control circuit 180. The inverter circuit 164 is an example of a drive circuit, the power relay 168 is an example of a third switch element, and the control circuit 180 is an example of a controller. The inverter circuit 164, electrical resistance element 166, power relay 168, connection device 170, and control circuit 180 are all mounted on a common circuit board 162.

[0051] The inverter circuit 164 is a power supply circuit that supplies power to the electric motor 134. In this embodiment, the electric motor 134 is a three-phase motor, and the inverter circuit 164 is a three-phase modulation inverter circuit. The inverter circuit 164 converts DC power from the battery 320 into three-phase AC power and supplies it to the electric motor 134. The inverter circuit 164 has a power input terminal 165A and a ground terminal 165B. The power input terminal 165A is electrically connected to the positive terminal 321A of the battery 320 via the power line L1, and the ground terminal 165B is electrically connected to the negative terminal 321B of the battery 320 via the ground line L2.

[0052] The power relay 168 is the main switching element that switches the power supply from the battery 320 to the inverter circuit 164 on and off. The input terminal of the power relay 168 is electrically connected to the positive terminal 321A of the battery 320 via the power line L1. The output terminal of the power relay 168 is electrically connected to the power input terminal 165A of the inverter circuit 164 without going through the electrical resistance element 166. The power relay 168 is, for example, a FET (Field Effect Transistor). However, the power relay 168 may also be a switching element other than a FET (for example, a bipolar transistor or a mechanical switching element).

[0053] The connection device 170 includes a precharge relay 172 and a discharge relay 174. The precharge relay 172 is an example of a first switch element and a first electrical switch element, and the discharge relay 174 is an example of a second switch element and a second electrical switch element.

[0054] The input terminal of the precharge relay 172 is electrically connected to the positive terminal 321A of the battery 320 via the power line L1. The output terminal of the precharge relay 172 is electrically connected to the power input terminal 165A of the inverter circuit 164 via the electrical resistance element 166. The input terminal of the discharge relay 174 is electrically connected to the negative terminal 321B of the battery 320 via the ground line L2. The output terminal of the discharge relay 174 is electrically connected to the power input terminal 165A of the inverter circuit 164 via the electrical resistance element 166. The precharge relay 172 and discharge relay 174 are, for example, FETs (Field Effect Transistors). However, the precharge relay 172 and discharge relay 174 may also be switch elements other than FETs (for example, bipolar transistors or mechanical switch elements).

[0055] The electrical resistance element 166 is, for example, an electrical resistor. As described above, the input terminal of the electrical resistance element 166 is electrically connected to the output terminal of the precharge relay 172 and the output terminal of the discharge relay 174. The output terminal of the electrical resistance element 166 is electrically connected to the power input terminal 165A of the inverter circuit 164. Note that the electrical resistance element 166 is not limited to an electrical resistor; any electrical element having a resistive component is acceptable. Also, the electrical resistance element 166 may be a variable resistor.

[0056] The control circuit 180 controls various elements mounted on the circuit board 162. The control circuit 180 includes, for example, a CPU, a multi-core CPU, and programmable devices (such as a Field Programmable Gate Array (FPGA) or Programmable Logic Device (PLD)).

[0057] Figure 6 is a flowchart showing the flow of the switching control process, and Figure 7 is a simplified diagram showing the switching pattern of the connection device 170. For example, when an operator uses the control device 230 to instruct the ship control system 10S to start, the battery 320 supplies power to each component of the ship control system 10S (e.g., the control circuit 180 of the MCU 139). The control circuit 180 executes the switching control process shown in Figure 6. The switching control process is a process for switching the power relay 168, the precharge relay 172, and the discharge relay 174, respectively.

[0058] Specifically, the control circuit 180 determines whether or not there is an instruction to start driving the electric motor 134 (S110). For example, when an operator uses the shift / throttle lever 240 or the joystick unit 250 to instruct the electric motor 134 to start driving, the BCU 300 transmits a drive start signal to the control circuit 180. Based on whether or not the drive start signal has been received, the control circuit 180 determines whether or not there is an instruction to start driving.

[0059] Here, in the initial state before the control circuit 180 receives the drive start signal, the power relay 168, precharge relay 172, and discharge relay 174 are all open. That is, the power input terminal 165A of the inverter circuit 164 is not electrically connected to either the positive terminal 321A or the negative terminal 321B of the battery 320.

[0060] If the control circuit 180 determines that there is no instruction to start driving (S110: NO), it maintains the initial state described above. If the control circuit 180 determines that there is an instruction to start driving (S110: YES), it sets the connection device 170 to the pre-charge pattern (S120). The pre-charge pattern is an example of the first connection pattern.

[0061] The pre-charge pattern is one in which the pre-charge relay 172 is closed and the discharge relay 174 is open. In other words, in the pre-charge pattern, the power input terminal 165A of the inverter circuit 164 is electrically connected to the positive terminal 321A of the battery 320 via the electrical resistance element 166. At this time, the power relay 168 remains open. Therefore, the current Ia from the positive terminal 321A flows to the power input terminal 165A of the inverter circuit 164 via the pre-charge relay 172 and the electrical resistance element 166 (see Figure 7). Thus, the electrical resistance element 166 functions as a pre-charge resistor. In other words, the electrical resistance element 166 suppresses the flow of inrush current from the battery 320 to the inverter circuit 164 and protects the circuit elements (capacitors, switch elements, etc.) that make up the inverter circuit 164.

[0062] The control circuit 180 closes the power relay 168 from the open state after a second reference time has elapsed from the time the connection device 170 is set to the pre-charge pattern (S130). As a result, according to this embodiment, power can be continuously supplied to the electric motor 134 while suppressing the generation of inrush current to the inverter circuit 164 when the electric motor 134 starts to drive. The second reference time is, for example, a sufficient time from the time the pre-charge pattern is set to reduce the generation of inrush current to the inverter circuit 164.

[0063] The control circuit 180 closes the power relay 168 and then releases the precharge pattern (S140). In this embodiment, the first reference time is an example of a time longer than the second reference time. Disconnecting the connection by the precharge pattern suppresses power loss in the electrical resistance element 166.

[0064] After the precharge pattern is released, the control circuit 180 determines whether or not there is an instruction to stop the electric motor 134 (S150). For example, if an operator uses the shift / throttle lever 240 or the joystick unit 250 to instruct the electric motor 134 to stop, the BCU 300 sends a drive stop signal to the control circuit 180. Based on whether or not the drive stop signal has been received, the control circuit 180 determines whether or not there is an instruction to stop the drive.

[0065] If the control circuit 180 determines that there is no instruction to stop the drive (S150: NO), it maintains a power supply state in which only the power relay 168 is closed. If the control circuit 180 determines that there is an instruction to stop the drive (S150: YES), it opens the power relay 168 from the closed state (S160). As a result, the MCU 139 enters a power-off state in which the power supply to the electric motor 134 is stopped.

[0066] The control circuit 180 opens the power relay 168 and then sets the connection device 170 to a discharge pattern (S170). The discharge pattern is an example of a second connection pattern.

[0067] The discharge pattern is one in which the precharge relay 172 is in an open state and the discharge relay 174 is in a closed state. That is, in the discharge pattern, the power input terminal 165A of the inverter circuit 164 is electrically connected to the negative terminal 321B of the battery 320 via the electrical resistance element 166. After the power relay 168 and the precharge relay 172 change from a closed state to an open state, charge accumulates in the internal circuitry (especially the capacitor) of the inverter circuit 164. However, due to the discharge pattern setting, current Ib flows from the power input terminal 165A of the inverter circuit 164 to the ground line L2 via the electrical resistance element 166 and the discharge relay 174 (see Figure 7). Therefore, the electrical resistance element 166 functions as a discharge resistor. That is, the electrical resistance element 166 discharges the charge accumulated in the inverter circuit 164.

[0068] The control circuit 180 terminates the switching control process by releasing the connection via the discharge pattern (S180) after a third reference time has elapsed from the time the connection device 170 is set to the discharge pattern. Releasing the discharge pattern suppresses leakage current from the inverter circuit 164. The third reference time is, for example, a sufficient time from the time the discharge pattern is set to discharge the charge accumulated in the inverter circuit 164.

[0069] (modified version) The technologies disclosed herein are not limited to the embodiments described above and can be modified in various forms without departing from their essence, for example, the following modifications are possible.

[0070] The configurations of the ship 10, ship control system 10S, and electric propulsion system 100 in the above embodiment are merely examples and can be modified in various ways. For example, in the above embodiment, an outboard motor electric propulsion system 100 is given as an example of a ship's propulsion system, but the ship's propulsion system may be an inboard motor, an inboard / outboard motor, a jet propulsion system, etc. The electric motor may be a multi-phase motor other than a three-phase motor, or a DC motor.

[0071] In the above embodiment, the electric propulsion system 100 has only an electric motor as a drive source, but the ship's propulsion system may be a hybrid type that has an engine in addition to the electric motor.

[0072] In the above embodiment, the drive circuit is not limited to the inverter circuit 164, but may be other power supply circuits, etc. The first switch element, the second switch element, and the third switch element are not limited to electrical types, but may be mechanical types. In the above embodiment, at least one of the power relay 168, the precharge relay 172, and the discharge relay 174 may not be placed on the circuit board 162, but on another circuit board, etc.

[0073] In the above embodiment, the connection device 170 had a configuration having two switch elements 172 and 174, but it may also be configured to switch the connection pattern on and off with a single switch element. However, with the configuration of the above embodiment, the on / off switching of the first connection pattern and the on / off switching of the second connection pattern can be performed independently.

[0074] In the switching control process shown in Figure 6, the control circuit 180 does not have to execute at least one of S130, S140, S170, and S180. [Explanation of symbols]

[0075] 10: Ship 10S: Ship control system 100: Electric propulsion system 134: Electric motor 139: MCU 162: Circuit board 164: Inverter circuit 165A: Power input terminal 165B: Ground terminal 166: Electrical resistance element 168: Power relay 170: Connection device 172: Precharge relay 174: Discharge relay 180: Control circuit 320: Battery 321A: Positive terminal 321B: Negative terminal

Claims

1. A ship propulsion system comprising an electric motor and a motor drive device for driving the electric motor, The motor drive device is A drive circuit that supplies power to the electric motor, having a power input terminal and a ground terminal connected to a ground line, Electrical resistance element, A connection device that performs a first connection pattern in which the power input terminal is electrically connected to a power line via the electrical resistance element, and a second connection pattern in which the power input terminal is electrically connected to the ground line via the electrical resistance element. A ship's propulsion system equipped with the following features.

2. A ship propulsion system according to claim 1, The aforementioned connection device, A first switch element having one end electrically connected to the power line and the other end electrically connected to the power input terminal via the electrical resistance element, A second switch element having one end electrically connected to the ground line and the other end electrically connected to the power input terminal via the electrical resistance element, A ship's propulsion system that has the following features.

3. A ship propulsion system according to claim 1 or claim 2, A ship propulsion system comprising a motor drive device further comprising a third switch element having one end electrically connected to the power line and the other end electrically connected to the power input terminal without the electrical resistance element.

4. A ship propulsion system according to any one of claims 1 to 3, Furthermore, it is equipped with a controller, A ship propulsion system in which the controller sets the connection device to the first connection pattern, provided that it has received an instruction to start driving the electric motor.

5. A ship propulsion system according to claim 4, The controller releases the connection according to the first connection pattern after a first reference time has elapsed from the time the connection device is set to the first connection pattern, in a ship propulsion system.

6. A ship propulsion system according to claim 4 or claim 5, The motor drive device further includes a third switch element, one end of which is electrically connected to the power line and the other end of which is electrically connected to the power input terminal without passing through the electrical resistance element. The controller is a ship propulsion system that, after a second reference time has elapsed from the time the connection device is set to the first connection pattern, changes the third switch element from an open state to a closed state.

7. A ship propulsion system according to any one of claims 1 to 6, Furthermore, it is equipped with a controller, A ship propulsion system in which the controller sets the connection device to the second connection pattern, provided that it has received an instruction to stop the operation of the electric motor.

8. A ship propulsion system according to claim 7, The controller disconnects the connection according to the second connection pattern after a third reference time has elapsed from the time the connection device is set to the second connection pattern, in a ship propulsion system.

9. A ship propulsion system according to any one of claims 1 to 8, The connection device has a first electrical switch element for setting and releasing the first connection pattern, A ship's propulsion system in which the first electrical switch element, the electrical resistance element, and the drive circuit are mounted on the same circuit board.

10. A ship propulsion system according to claim 9, The connection device further includes a second electrical switch element for setting and releasing the second connection pattern. A ship propulsion system, wherein the circuit board is further equipped with the second electrical switch element.

11. A ship propulsion system according to claim 9 or claim 10, The motor drive device further includes a third switch element, one end of which is electrically connected to the power line and the other end of which is electrically connected to the power input terminal without passing through the electrical resistance element. A ship propulsion system, wherein the circuit board is further equipped with the third switch element.

12. The hull and, A ship comprising a ship propulsion engine according to any one of claims 1 to 11, which is disposed on the hull.

13. A motor drive device for driving an electric motor, A drive circuit that supplies power to the electric motor, having a power input terminal and a ground terminal connected to a ground line, Electrical resistance element, A connection device that performs a first connection pattern in which the power input terminal is electrically connected to a power line via the electrical resistance element, and a second connection pattern in which the power input terminal is electrically connected to the ground line via the electrical resistance element. A motor drive device equipped with the following features.

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