Engine-driven electric generator

Abstract

A power supply is capable of supplying electric power to a starter that starts an engine. An inverter is connected to a generator that generates electric power driven by the engine. The inverter has a first conversion circuit that converts alternating current generated by the generator into direct current and a second conversion circuit that converts the direct current into alternating current to be supplied to a load. An output terminal outputs alternating current from the inverter to the load. A detection circuit detects the load connected to the output terminal. A control circuit stops or starts the engine in accordance with the load detected by the detection circuit. The control circuit causes alternating current to be generated in the second conversion circuit by applying a direct current voltage from the power supply to the second conversion circuit during a period in which the engine is stopped. The control circuit is configured to decide whether to continue the stop of the engine or to start the engine based on whether the detection circuit detects the load.

Description

Technical Field

[0001] This invention relates to an engine-driven generator. Background Technology

[0002] Engine-driven generators are portable and widely used as recreational and backup power sources. Loads connected to engine-driven generators can be stopped or disconnected. Since the engine continues to run at idle speed even when the load is stopped or disconnected, fuel is unnecessarily consumed. Therefore, Patent Document 1 proposes a method to automatically start or stop the engine (i.e., the engine) based on the presence or absence of a load.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 5449014 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] During engine shutdown, the generator also stops. Therefore, the invention in Patent Document 1 employs a load detection circuit that detects the load by applying a DC voltage from a DC power source to the load. However, the invention in Patent Document 1 has difficulty detecting loads with high impedance. Therefore, the object of the present invention is to detect even loads with high impedance, thereby restarting the engine with good accuracy.

[0008] Methods for solving problems

[0009] This invention provides, for example, an engine-driven generator, wherein,

[0010] The engine-driven generator has the following features:

[0011] engine;

[0012] A starter motor, which starts the engine;

[0013] A power source, which supplies power to the starter motor;

[0014] A generator that generates electricity, driven by the engine;

[0015] An inverter having a first conversion circuit that converts AC generated by the generator into DC and a second conversion circuit that converts the DC into AC and supplies it to the load;

[0016] The output terminal outputs AC power from the inverter to the load.

[0017] A detection circuit that detects the load connected to the output terminal; and

[0018] A control circuit that stops or starts the engine based on the load detected by the detection circuit.

[0019] The control circuit is configured to generate AC in the second conversion circuit by applying a DC voltage from the power source to the second conversion circuit during the period when the engine is stopped, and to determine whether to continue the engine stop or start the engine based on whether the detection circuit detects a load.

[0020] Invention Effects

[0021] According to the present invention, even high-impedance loads can be detected, thereby enabling the engine to be restarted with good accuracy.

[0022] Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings. It should be noted that, in the drawings, the same or identical components are labeled with the same reference numerals. Attached Figure Description

[0023] The accompanying drawings are included in the specification, form a part of the specification, and illustrate embodiments of the invention. The drawings, together with the description in the specification, serve to illustrate the principles of the invention.

[0024] Figure 1 This is a diagram illustrating an engine-driven generator.

[0025] Figure 2 This is a diagram illustrating an engine-driven generator.

[0026] Figure 3 This is a diagram illustrating an engine-driven generator.

[0027] Figure 4 This is a diagram illustrating an engine-driven generator.

[0028] Figure 5 It is a flowchart representing the operating mode.

[0029] Figure 6 This is a flowchart representing the stop mode. Detailed Implementation

[0030] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the invention to which the technical solution pertains, and the combination of features described in the embodiments is not limited to the content necessary for the invention. Any combination of two or more features from the plurality of features described in the embodiments is also possible. Furthermore, the same or identical components are labeled with the same reference numerals, and repeated descriptions are omitted.

[0031] exist Figure 1 In the engine-driven generator 100 shown, a starter 101 is connected to the crankshaft of an engine 102. The starter 101 rotates the crankshaft, starting the engine 102. The engine 102 burns fuel (e.g., gasoline, natural gas, hydrogen) in its working cylinders. The crankshaft (output shaft) rotates synchronously with the piston reciprocating within the working cylinders. The rotor of a generator 103 is connected to the crankshaft. The generator 103 generates electricity through rotor rotation. The stator of the generator 103 has U-winding, V-winding, and W-winding. The U-winding, V-winding, and W-winding are connected to a rectifier circuit 111 within an inverter 110. The rectifier circuit 111 and the smoothing circuit 112 are converter circuits that convert the alternating current generated by the generator 103 into direct current. Specifically, the rectifier circuit 111 rectifies the alternating current generated in the U-winding, V-winding, and W-winding to generate a pulsed current. The rectifier circuit 111 can also be constructed from a bridge circuit, etc., wherein the bridge circuit is composed of multiple rectifier elements (e.g., diodes, thyristors, transistors). The smoothing circuit 112 smooths the pulsed current to generate DC. The smoothing circuit 112 can be constructed from, for example, an electrolytic capacitor. Here, the smoothed DC voltage can also be referred to as the DC link voltage or the DC bus voltage. The DC voltage (DC bus voltage) output from the smoothing circuit 112 is input to the AC generation circuit 113. The AC voltage generated by the AC generation circuit 113 is supplied to the load 109 from the output terminal 115.

[0032] The inverter control circuit 117 controls the AC generation circuit 113 based on the load current I2 detected by the current detection circuit 114. The inverter control circuit 117 can also be constructed from hardware such as a CPU (Central Processing Unit), an ASIC (Application-Specific Integrated Circuit), and memory. The functions of the inverter control circuit 117 described below can also be implemented by the CPU executing a control program stored in memory. When the load current I2 becomes zero, the inverter control circuit 117 stops the AC generation circuit 113. The AC generation circuit 113 is constructed, for example, from a hybrid bridge circuit or a bridge circuit based on multiple FETs (Field-Effect Transistors). In this case, the inverter control circuit 117 maintains the AC voltage at a target voltage by controlling the on-time of the control signals (drive signals) supplied to the gates of each FET. The inverter control circuit 117 can also send the value of the load current I2 to the controller 120. The power supply circuit 116 converts the voltage supplied from the generator 103 or the DC-DC converter 123, thereby generating the operating voltage of the inverter control circuit 117. Specifically, during the period when the engine 102 is rotating, the power supply circuit 116 converts the alternating current generated by the generator 103 into direct current. During the period when the engine 102 is stopped, the power supply circuit 116 converts the alternating current generated in the secondary winding of the transformer 125 of the DC-DC converter 123 into direct current.

[0033] The controller 120 rotates and stops the starter 101 by switching the relay 105 on and off. The battery 104 is a rechargeable battery that supplies DC voltage to the starter 101 via the relay 105. The battery 104 can also be charged by electricity generated by the generator 103. Since this charging circuit is well-known, it is not shown.

[0034] DC-DC converter 123 is a circuit that steps down or boosts the battery voltage Vbat supplied from battery 104 to generate the operating voltage for power supply circuit 116 and CPU 121. Additionally, DC-DC converter 123 also boosts the battery voltage Vbat to generate an analog DC bus voltage. In DC-DC converter 123, drive circuit 124 is connected to the primary winding of transformer 125 and switches the voltage applied to the primary winding. Transformer 125 has a primary winding and two secondary windings. Power supply circuit 116 is connected to one of the secondary windings of transformer 125, and the AC power generated in this secondary winding is supplied to power supply circuit 116. The power supply voltage for CPU 121 can also be generated by converting the battery voltage Vbat using DC-DC converter 123 or a DC-DC converter (not shown). The rectifier-smoothing circuit 127 is connected to the secondary winding of the other side of the transformer 125, rectifying and smoothing the AC generated in the secondary winding to generate a DC voltage (simulating a DC bus voltage), and applying this DC voltage to the input of the AC generation circuit 113 via switch 130. The level of this DC voltage is sufficient for the AC generation circuit 113 to generate AC. The CPU 121 opens switch 130 when the engine 102 stops and closes switch 130 when the engine 102 is rotating. In other words, during the period when the engine 102 is stopped, the AC generation circuit 113 is supplied with DC voltage from the DC-DC converter 123. During the operation of the engine 102, the AC generation circuit 113 is supplied with DC voltage from the generator 103, the rectifier circuit 111, and the smoothing circuit 112. Switch 130 can also be a semiconductor switch (transistor), a relay, or a diode.

[0035] CPU 121 is a central processing unit (processor circuit) that controls relay 105 and switch 130 by executing a control program. CPU 121 can also be composed of a single processor circuit, multiple processor circuits, an ASIC (Application-Specific Integrated Circuit), or an FPGA (Field-Programmable Gate Array). The engine-driven generator 100 has a power generation mode (operating mode) where the engine 102 rotates and the generator 103 generates electricity, and a stop mode where the engine 102 stops and the generator 103 does not generate electricity. CPU 121 stops the engine 102 when a stop condition is met. For example, the engine 102 stops by cutting off power to a fuel pump (not shown). The stop condition could be, for example, that the load current I2 becomes less than a predetermined threshold. Alternatively, the stop condition could be, for example, that the load current I2 becomes less than a predetermined threshold and the battery voltage Vbat becomes greater than a predetermined threshold. If the battery voltage Vbat is less than the predetermined threshold (in the case of insufficient charging), CPU 121 may become unable to detect the load 109 and become unable to start the engine 102 by the starter 101 during the stop period (stop mode). Therefore, the CPU 121 can also stop the engine 102 after the battery 104 has been sufficiently charged by the generator 103.

[0036] ●Load detection method I

[0037] according to Figure 1 When the restart conditions of engine 102 are met, CPU 121 switches switch 130 from open to closed and relay 105 from closed to open, thereby activating starter 101 and restarting engine 102. It should be noted that the timing for switching switch 130 from open to closed can also be after the DC bus voltage Vdc output from smoothing circuit 112 reaches the target voltage and stabilizes. Here, the restart condition can also be that the battery voltage Vbat becomes less than a predetermined threshold. Figure 1 As shown, when the engine 102 is stopped, the rectifier smoothing circuit 127 generates a DC voltage and supplies it to the AC generation circuit 113, which in turn generates AC voltage and supplies it to the load 109. Therefore, when the load 109 is connected to the output terminal 115 while the engine 102 is stopped, load current flows to the load 109, thereby reducing the battery voltage Vbat. Thus, the CPU 121 can detect or identify the situation where the load 109 is connected to the output terminal 115 by monitoring the battery voltage Vbat while the engine 102 is stopped.

[0038] ●Load detection method II

[0039] Figure 2This indicates that the condition of load 109 is detected based on the change in the analog DC bus voltage Vdc supplied from the DC-DC converter 123 to the AC generation circuit 113. Figure 2 In the middle, in with Figure 1 The same reference numerals are used in the common projects, and their descriptions are cited. When engine 102 is stopped, and load 109 is connected to output terminal 115, the DC bus voltage Vdc decreases because load current flows to load 109. CPU 121 can detect or identify the situation where load 109 is connected to output terminal 115 by monitoring the DC bus voltage Vdc when engine 102 is stopped. Figure 2 As shown, the voltage detection circuit 128 is connected between the output terminal of the rectifier smoothing circuit 127 and the input terminal of the AC generation circuit 113. Therefore, the voltage detection circuit 128 detects the analog DC bus voltage Vdc supplied from the rectifier smoothing circuit 127 to the AC generation circuit 113 and reports the DC bus voltage Vdc to the CPU 121. In practice, a detection voltage proportional to the DC bus voltage Vdc is applied to the port of the CPU 121 via an optocoupler or the like. When the DC bus voltage Vdc is less than a predetermined threshold, the CPU 121 determines that the restart condition has been met and switches the relay 105 from closed to open. When the DC bus voltage Vdc is above the predetermined threshold, the CPU 121 determines that the restart condition has not been met and keeps the relay 105 closed.

[0040] ●Load detection method III

[0041] Figure 3 This indicates that the condition of load 109 is detected by inputting the analog DC bus voltage Vdc to the AC generation circuit 113 while the engine 102 is stopped, and monitoring the current flowing to the input side of the AC generation circuit 113. Figure 3 In the middle, in with Figure 1 or Figure 2 The same reference numerals are used in the common projects, and their descriptions are cited. When engine 102 is stopped, load current I2 flows to load 109 when load 109 is connected to output terminal 115. When load current I2 flows to load 109, the current flowing from DC-DC converter 123 to the input of AC generation circuit 113 (input-side current I1) also increases. Therefore, CPU 121 detects input-side current I1 via current detection circuit 129, and based on the change in input-side current I1, detects or identifies the situation where load 109 is connected to output terminal 115 when engine 102 is stopped. For example, a necessary condition for restarting could also be that input-side current I1 becomes above a predetermined threshold.

[0042] ●Load detection method IV

[0043] Figure 4 This means that by inputting the analog DC bus voltage Vdc to the AC generation circuit 113 while the engine 102 is stopped, the load current I2 flowing from the AC generation circuit 113 to the load 109 is monitored, thereby detecting the condition of the load 109. Figure 4 In the middle, in with Figures 1 to 3 The same reference numerals are used for common items in the drawings, and their descriptions are cited. When engine 102 is stopped, load current I2 flows to load 109 when load 109 is connected to output terminal 115. Current detection circuit 114 is connected between AC generation circuit 113 and load 109 and is capable of detecting load current I2. Inverter control circuit 117 is connected to CPU 121 via an isolated communication circuit (e.g., optocoupler). Inverter control circuit 117 notifies CPU 121 of the value of load current I2 via the isolated communication circuit. CPU 121 detects or identifies the situation where load 109 is connected to output terminal 115 when engine 102 is stopped based on changes in load current I2. For example, a restart condition could also be that load current I2 reaches or exceeds a predetermined threshold.

[0044] ●Flowchart

[0045] Figure 5 It is a flowchart representing the operating mode.

[0046] In S501, CPU121 starts engine 102. For example, CPU121 connects battery 104 to starter 101 by opening relay 105, causing starter 101 to rotate. As a result, engine 102 begins to rotate.

[0047] In S502, CPU121 detects the load current I2 and the battery voltage Vbat. The load current I2 is detected by the current detection circuit 114 and input to CPU121 via the inverter control circuit 117.

[0048] In S503, CPU121 determines whether the stop condition is met based on the load current I2 and the battery voltage Vbat. For example, if the load current I2 is less than the threshold Ith1 and the battery voltage Vbat is greater than Vth1, CPU121 determines that the stop condition is met. When the load 109 is removed from the output terminal 115 and the load 109 stops, the load current I2 becomes less than the threshold Ith1. If the load current I2 is greater than the threshold Ith1, CPU121 determines that the stop condition is not met. If the battery voltage Vbat is less than Vth1, CPU121 also determines that the stop condition is not met. If the stop condition is not met, CPU121 returns to S502. If the stop condition is met, CPU121 enters S504.

[0049] In S504, CPU121 transitions from operating mode (power generation mode) to stop mode.

[0050] Figure 6 This is a flowchart representing the stop mode.

[0051] In S601, CPU 121 stops engine 102. For example, CPU 121 switches relay 105 from open to closed. Further, CPU 121 stops engine 102 by stopping the fuel supply to engine 102.

[0052] In S602, CPU 121 supplies DC voltage to inverter 110 to begin detecting load 109. For example, CPU 121 applies the analog DC bus voltage generated by DC-DC converter 123 to the input bus of AC generation circuit 113 by turning on switch 130. Thus, AC generation circuit 113 begins generating AC based on the analog DC bus voltage. Additionally, CPU 121 periodically monitors battery voltage Vbat, DC bus voltage Vbus, input current I1, or load current I2 to detect if load 109 is connected to output terminal 115. The condition of load 109 being electrically connected to output terminal 115 and the condition of load 109 being physically connected to output terminal 115 switching from a stopped state to an operating state have the same meaning. In other words, even when load 109 is physically connected to output terminal 115, there may be a situation where load 109 is not electrically connected to engine-driven generator 100. For example, there may be a situation where the power plug of load 109 is connected to output terminal 115, but the power switch of load 109 is turned off. Therefore, generally speaking, when load 109 is connected to engine-driven generator 100 (output terminal 115), it means that load 109 is electrically connected to output terminal 115.

[0053] In S603, CPU121 determines whether the restart conditions are met. For example, CPU121 may determine that the restart conditions are met when the battery voltage Vbat becomes less than a predetermined threshold Vth2. Alternatively, CPU121 may determine that the restart conditions are met when the DC bus voltage Vbus becomes less than a predetermined threshold Vth3. Alternatively, CPU121 may determine that the restart conditions are met when the input current I1 becomes greater than a predetermined threshold Ith2. Alternatively, CPU121 may determine that the restart conditions are met when the load current I2 becomes greater than a predetermined threshold Ith3. Alternatively, the restart conditions may be met by satisfying two, three, or all of these four conditions. When the restart conditions are not met, CPU121 returns to S602. When the restart conditions are met, CPU121 enters S604.

[0054] In S604, CPU121 transitions to operating mode. In other words, CPU121 enters S501 and restarts engine 102.

[0055] Summary

[0056] [Viewpoint 1]

[0057] like Figure 1As shown, battery 104 is an example of a power source (e.g., DC power supply, secondary battery) used to supply power to starter motor 101 of the engine. Generator 103 is an example of a generator that generates electricity driven by engine 102. Inverter 110 is an example of an inverter having a first conversion circuit (e.g., rectifier circuit 111, smoothing circuit 112) that converts AC generated by generator 103 to DC and a second conversion circuit (e.g., AC generation circuit 113) that converts DC to AC and supplies it to the load. Output terminal 115 is an example of an output terminal from inverter 110 that outputs AC to load 109. Current detection circuit 114, current detection circuit 129, voltage detection circuit 122, and voltage detection circuit 128 are examples of detection circuits that detect the load 109 connected to output terminal 115. Controller 120 and CPU 121 are examples of control circuits that stop or start engine 102 based on the load detected by the detection circuits. The control circuit (e.g., CPU 121) is configured to generate AC in the second conversion circuit by applying a DC voltage from the power supply to the second conversion circuit during the period when the engine 102 is stopped. Furthermore, the control circuit (e.g., CPU 121) is configured to determine whether to continue stopping the engine 102 or start the engine 102 based on whether the detection circuit detects a load. According to this embodiment, by outputting AC from output terminal 115 during the period when the engine 102 is stopped, the CPU 121 can detect not only low-impedance loads 109 but also high-impedance loads 109. Therefore, since the CPU 121 can accurately detect the connected load 109 during the period when the engine 102 is stopped, the engine 102 can be restarted accurately. In addition, since the detection accuracy of the load 109 is improved, the stopping of the engine 102 can be maintained accurately. This will reduce fuel consumption of the engine 102.

[0058] [Viewpoint 2]

[0059] Voltage detection circuit 128 is an example of a voltage detection circuit that detects the voltage input to the second conversion circuit. The control circuit (e.g., CPU 121) can also be configured to determine whether to continue stopping or starting the engine 102 during engine 102 shutdown, based on changes in the input voltage toward the second conversion circuit detected by the voltage detection circuit. When load 109 is connected to output terminal 115, the input voltage of the second conversion circuit decreases because current flows from the second conversion circuit to the load 109. In other words, the connection of load 109 to output terminal 115 can be detected with good accuracy by monitoring changes in the input voltage toward the second conversion circuit.

[0060] [Viewpoint 3]

[0061] Voltage detection circuit 122 is an example of a voltage detection circuit that detects the power supply voltage (e.g., Vbat) of a power source. The control circuit (e.g., CPU 121) can also determine whether to continue stopping the engine or start it based on changes in the power supply voltage detected by the voltage detection circuit during engine 102's shutdown. When load 109 is connected to output terminal 115, the inter-terminal voltage (power supply voltage) of battery 104 decreases because current flows from the second conversion circuit to load 109. In other words, the connection of load 109 relative to output terminal 115 can be detected with good accuracy by monitoring changes in the power supply voltage of battery 104.

[0062] [Viewpoint 4]

[0063] The current detection circuit 129 is an example of a current detection circuit that detects the current flowing from the power source to the second conversion circuit. During the period when the engine 102 is stopped, the control circuit (e.g., CPU 121) applies a DC voltage from the power source to the second conversion circuit, thereby generating AC current in the second conversion circuit. The control circuit (e.g., CPU 121) can also determine whether to continue stopping or starting the engine 102 based on changes in the current detected by the current detection circuit. When the load 109 is connected to the output terminal 115 by applying an AC voltage, current flows from the power source (e.g., battery 104, DC-DC converter 123) to the second conversion circuit. Therefore, by monitoring this current, the CPU 121 can accurately detect the connection of the load 109 to the output terminal 115 during the period when the engine 102 is stopped.

[0064] [Viewpoint 5]

[0065] The current detection circuit 114 is an example of a current detection circuit that detects the current flowing from the second conversion circuit to the load 109. During the period when the engine 102 is stopped, the control circuit (e.g., CPU 121) applies a DC voltage from the power supply to the second conversion circuit, thereby generating AC current in the second conversion circuit. The control circuit (e.g., CPU 121) can also determine whether to continue stopping or starting the engine 102 based on changes in the current detected by the current detection circuit. When the load 109 is connected to the output terminal 115 by applying an AC voltage, current flows from the second conversion circuit to the load 109. Therefore, by monitoring this current, the CPU 121 can accurately detect the connection of the load 109 to the output terminal 115 during the period when the engine 102 is stopped.

[0066] [Viewpoint 6]

[0067] DC-DC converter 123 is an example of a third conversion circuit disposed between a power supply and a second conversion circuit, which converts the DC power supply voltage supplied from the power supply into a DC input voltage directed to the second conversion circuit. The DC input voltage directed to the second conversion circuit (e.g., AC generation circuit 113) is a DC voltage that can be generated by inputting this DC input voltage into the second conversion circuit. Sometimes, a lower limit voltage exists in the input voltage of the third conversion circuit, which is required when the third conversion circuit outputs an AC voltage. In this case, it is desirable for the DC input voltage input to the second conversion circuit to be above the lower limit voltage.

[0068] [Viewpoint 7]

[0069] The control circuit (e.g., CPU 121) stops the supply of power from the power source to the second conversion circuit when the engine 102 transitions from a stopped state to an operating state. This is because the generator 103 supplies power to the second conversion circuit when the engine 102 is rotating. On the other hand, the control circuit (e.g., CPU 121) is configured to start the supply of power from the power source to the second conversion circuit when the engine 102 transitions from an operating state to a stopped state.

[0070] This invention is not limited to the above-described embodiments, and various modifications and alterations can be made within the scope of the invention's intent.

Claims

1. An engine-driven generator, wherein, The engine-driven generator has the following features: engine; A starter motor, which starts the engine; A power source, which supplies power to the starter motor; A generator that generates electricity, driven by the engine; An inverter having a first conversion circuit that converts AC generated by the generator into DC and a second conversion circuit that converts the DC into AC and supplies it to the load; The output terminal outputs AC power from the inverter to the load. A detection circuit that detects the load connected to the output terminal; as well as A control circuit that stops or starts the engine based on the load detected by the detection circuit. The control circuit is configured to generate AC in the second conversion circuit by applying a DC voltage from the power source to the second conversion circuit during the period when the engine is stopped, and to determine whether to continue the engine stop or start the engine based on whether the detection circuit detects a load.

2. The engine-driven generator according to claim 1, wherein, The detection circuit includes a voltage detection circuit for detecting the voltage input to the second conversion circuit. The control circuit is configured to generate AC in the second conversion circuit by applying a DC voltage from the power source to the second conversion circuit during the period when the engine is stopped, and to determine whether to continue stopping the engine or start the engine based on the change in the input voltage toward the second conversion circuit detected by the voltage detection circuit.

3. The engine-driven generator according to claim 1, wherein, The detection circuit includes a voltage detection circuit for detecting the power supply voltage of the power source. The control circuit is configured to generate AC in the second conversion circuit by applying a DC voltage from the power supply to the second conversion circuit during the period when the engine is stopped, and to determine whether to continue stopping the engine or start the engine based on the change in the power supply voltage detected by the voltage detection circuit.

4. The engine-driven generator according to claim 1, wherein, The detection circuit includes a current detection circuit for detecting the current flowing from the power source to the second conversion circuit. The control circuit is configured to generate AC in the second conversion circuit by applying a DC voltage from the power source to the second conversion circuit during the period when the engine is stopped, and to determine whether to continue stopping the engine or start the engine based on the change in current detected by the current detection circuit.

5. The engine-driven generator according to claim 1, wherein, The detection circuit includes a current detection circuit for detecting the current flowing from the second conversion circuit to the load. The control circuit is configured to generate AC in the second conversion circuit by applying a DC voltage from the power source to the second conversion circuit during the period when the engine is stopped, and to determine whether to continue stopping the engine or start the engine based on the change in current detected by the current detection circuit.

6. The engine-driven generator according to any one of claims 1 to 5, wherein, The engine-driven generator also has a third conversion circuit, which is disposed between the power source and the second conversion circuit, and converts the DC power supply voltage supplied from the power source into a DC input voltage directed towards the second conversion circuit. The DC input voltage toward the second conversion circuit is a DC voltage such that the second conversion circuit can generate AC by inputting this DC input voltage.

7. The engine-driven generator according to any one of claims 1 to 6, wherein, The control circuit is configured as follows: When the engine transitions from a stopped state to an operating state, the supply of electricity from the power source to the second conversion circuit is stopped. When the engine transitions from the operating state to the stopped state, power is supplied from the power source to the second conversion circuit.

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