power generation equipment

Abstract

A power generation device (1) comprises: a power generator (10); a power conversion circuit (21); a first interrupting circuit (23); a second interrupting circuit (24); a first monitoring circuit (25) that monitors output current flowing from the power generator (10) to the power conversion circuit (21) and also outputs a first interrupt signal when the absolute value of the output current exceeds a first predetermined value; and a second monitoring circuit (26) that monitors the total value of the output voltages of the respective phases of the power generator (10) and also outputs a second interrupt signal when the absolute value of the total value exceeds a second predetermined value. The first interrupting circuit (23) electrically interrupts the connection between the power generator (10) and the power conversion circuit (21) in accordance with the output of the first interrupt signal or the second interrupt signal. The second interrupting circuit (24) electrically interrupts the connection between three-phase coils (Lu, Lv, Lw) and a neutral point (N) in accordance with the output of the first interrupt signal or the second interrupt signal.

Description

[Technical Field]

[0001] The present disclosure relates to a power generating device including a rotating field generator. [Background technology]

[0002] A permanent magnet generator includes a stator with coils for each phase and a rotor with multiple permanent magnets as a field magnet. The multiple permanent magnets are arranged in the direction of rotation of the rotor, alternating polarity. The permanent magnets of the rotor constantly generate magnetic flux that intersects with the stator coils. Therefore, in principle, a permanent magnet generator will continue to generate electricity as long as the rotor is rotating. In other words, a permanent magnet generator will continue to generate electricity even if a malfunction such as a short circuit occurs within the generator. In this regard, Patent Document 1 discloses a protection circuit that stops the power supply from the generator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2007 / 0030606 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, the rotor of a permanent magnet generator constantly generates magnetic flux, and therefore power generation cannot be stopped while the rotor is rotating. Therefore, if a short circuit occurs inside the generator, there is a concern that excessive damage may occur to the generator or related equipment connected downstream.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to provide a power generating device that is capable of preventing the progression of damage caused by a short circuit that occurs inside the generator. [Means for solving the problem]

[0006] A power generation device according to one aspect of the present disclosure includes a generator having a stator including a three-phase coil, a power conversion circuit that converts AC power output from the generator into DC power, a first shutdown circuit provided between the output of the generator and the input of the power conversion circuit, a second shutdown circuit provided between the three-phase coil and a neutral point, a first monitoring circuit that monitors an output current flowing from the generator to the power conversion circuit and outputs a first shutdown signal when the absolute value of the output current exceeds a first predetermined value, and a second monitoring circuit that monitors a sum of output voltages of the generator's phases and outputs a second shutdown signal when the absolute value of the sum exceeds a second predetermined value. The first shutdown circuit electrically shuts off the connection between the generator and the power conversion circuit in response to the output of the first shutdown signal or the second shutdown signal, and the second shutdown circuit electrically shuts off the connection between the three-phase coil and the neutral point in response to the output of the first shutdown signal or the second shutdown signal.

[0007] The first monitoring circuit may monitor a voltage corresponding to the output current obtained by a current sensor provided between the output of the generator and the input of the power conversion circuit, as the monitoring of the output current. The power conversion circuit may include a pair of switching elements functioning as rectifying elements in each phase, and the first monitoring circuit may monitor the voltage of each of the pair of switching elements, as the monitoring of the output current. The generator may be a permanent magnet synchronous generator. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a power generating device that is capable of preventing the progression of damage caused by a short circuit that occurs inside the generator. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a power generation device. [Figure 2] FIG. 2 is a diagram showing an example of an intra-phase short circuit in the power generating device shown in FIG. [Figure 3A]FIG. 3A is a diagram showing an example of a phase-to-phase short circuit in the power generating device shown in FIG. [Figure 3B] FIG. 3B is a diagram showing an example of a phase-to-phase short circuit in the power generating device shown in FIG. [Figure 4] FIG. 4 is a diagram illustrating an example of a ground fault in the power generating device illustrated in FIG. [Figure 5] FIG. 5 is a functional block diagram of a power generating device according to an embodiment of the present disclosure. [Figure 6] FIG. 6 is a circuit diagram illustrating an example of a first monitoring circuit according to an embodiment of the present disclosure. [Figure 7] FIG. 7 is a circuit diagram illustrating an example of a second monitoring circuit according to an embodiment of the present disclosure. [Figure 8] FIG. 8 is a circuit diagram illustrating another example of the first monitoring circuit according to the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, power generation devices 1 according to several embodiments of the present disclosure will be described. Note that common parts in the various drawings will be given the same reference numerals, and duplicated explanations will be omitted.

[0011] First, a phenomenon that occurs when a short circuit occurs in a power generating device 1 configured without the protection circuit according to this embodiment will be described. FIG. 1 is a diagram showing an example of the configuration of a power generating device 100 in which the protection circuit according to this embodiment is omitted from the configuration of the power generating device 1. As shown in FIG. 1, the power generating device 100 includes a generator 10 and a power converter 20. The power converter 20 includes a power conversion circuit (converter circuit) 21 and a control unit 22. However, the power generating device 100 does not have a first shutoff circuit 23, a second shutoff circuit 24, a first monitoring circuit 25, and a second monitoring circuit 26 (see FIGS. 5 to 9), which are protection circuits according to this embodiment described below.

[0012] The generator 10 includes a rotor (not shown) as a field magnet and a stator 11 including three-phase coils. The generator generates and outputs three-phase AC current as the rotor rotates. The generator 10 is, for example, a permanent magnet synchronous generator. In this case, the rotor has multiple permanent magnets aligned in the direction of rotation of the rotor. The multiple permanent magnets are aligned in the direction of rotation with alternating polarities. The rotor is connected to the rotating shaft of a drive source (not shown), such as a turbine or electric motor.

[0013] The stator 11 includes an iron core (not shown) and three-phase coils wound around the teeth (not shown) of the iron core. The three-phase coils are a U-phase coil Lu, a V-phase coil Lv, and a W-phase coil Lw. One end of each coil functions as the output end of the generator 10, and the other ends of each coil are connected to each other at a neutral point N. In other words, the coils Lu, Lv, and Lw are connected in a so-called star connection. Note that each coil may be composed of multiple coils connected in parallel or in series.

[0014] The power conversion circuit 21 converts AC power output from the generator 10 into DC power. The power conversion circuit 21 outputs, for example, positive and negative DC voltages. The power conversion circuit 21 includes a switching circuit 21A, a smoothing circuit 21B, and a filter circuit 21C. The switching circuit 21A includes a pair of switching elements functioning as rectifier elements for each phase. That is, the switching circuit 21A includes a pair of switching elements Tr1 and Tr2 provided for the U phase, a pair of switching elements Tr3 and Tr4 provided for the V phase, and a pair of switching elements Tr5 and Tr6 provided for the W phase. Each switching element is a power semiconductor such as a MOSFET, a thyristor, or an IGBT. The on / off of each switching element is controlled by the control unit 22 to ultimately obtain a desired output voltage.

[0015] The smoothing circuit 21B has a known configuration including a pair of capacitors (DC link capacitors) C1 and C2 connected in series, and smoothes the positive and negative pulsating currents output from the switching circuit 21A. The potential between the capacitors C1 and C2 is set to ground and is connected to the ground terminal G.

[0016] The filter circuit 21C has a known configuration including an inductor (not shown) etc. The filter circuit 21C removes common mode noise and normal mode noise and outputs DC power of a voltage set by the control unit 22. For example, a load 50 is connected between the positive output (+) of the filter circuit 21C and the ground terminal G, and between the negative output (-) and the ground terminal G, respectively.

[0017] The control unit 22 controls the overall operation of the power generation device 100. For example, the control unit 22 controls the output of a gate signal to the switching circuit 21A, performs feedback control to stabilize the output voltage, acquires measurement values ​​from various sensors (not shown), etc. The control unit 22 may be configured as, for example, a computer.

[0018] Next, we will explain short circuits that occur within the generator 10. There are three types of short circuits with different short circuit paths that can occur within the generator 10. These three types of short circuits are an intra-phase short circuit, an interphase short circuit, and a grounding fault.

[0019] (Intra-phase short circuit) 2 is a diagram showing an example of an intra-phase short circuit in the power generation device 100 shown in FIG. 1. An intra-phase short circuit in the generator 10 is a short circuit that occurs between two points in the conduction path of one phase. As an example, FIG. 2 shows a short circuit that occurs between two points in the U-phase coil Lu. This short circuit reduces the coil length that intersects with the magnetic flux, resulting in a decrease in the U-phase output voltage.

[0020] The control unit 22 controls the switching circuit 21A to maintain the output voltage during normal operation. For example, the control unit 22 measures the output voltage from the filter circuit 21C and controls the on / off of the switching elements Tr1 to Tr6 based on this measurement. If the U-phase output voltage drops under this control, the control unit 22 extends the on-time of the switching elements Tr1 and Tr2, thereby increasing the U-phase output current. In this case, the increase in output current may at least cause heating of the short-circuited area.

[0021] (phase-to-phase short circuit) 3A and 3B are diagrams illustrating an example of a phase-to-phase short circuit in the power generation device 100 shown in FIG. 1. A phase-to-phase short circuit in the generator 10 is a short circuit that occurs between conduction paths of different phases. As an example, FIGS. 3A and 3B illustrate a short circuit that occurs between a U-phase conduction path (e.g., coil Lu) and a V-phase conduction path (e.g., coil Lv). As shown in FIG. 3A, when a phase-to-phase short circuit occurs, a closed circuit is formed that runs from the shorted location to the shorted location via the switching elements (e.g., Tr1 and Tr4) that were on when the short circuit occurred and capacitors C1 and C2. Because the impedance of this closed circuit is approximately zero, a large DC current instantly flows from capacitors C1 and C2. This may burn out circuit components on the closed circuit.

[0022] In addition, as shown in Figure 3B, a closed circuit is also formed via the neutral point N. Since the rotor continues to rotate and current continues to flow while the short circuit persists, there is a possibility that the short circuited area will continue to heat up.

[0023] (ground fault) FIG. 4 is a diagram illustrating an example of a ground fault in the power generation device 100 shown in FIG. 1. A ground fault in the generator 10 is a short circuit that occurs between a coil of one phase and the ground. FIG. 4 illustrates, as an example, a short circuit that occurs between a U-phase conduction path (e.g., coil Lu) and the stator 11 of the generator 10. As shown in FIG. 4, when a ground fault occurs, a closed circuit is formed that runs from the shorted location through a switching element (e.g., Tr1) that was on when the short circuit occurred, capacitor C1, the ground terminal G of the filter circuit, and the stator 11, and returns to the shorted location. Because the impedance of this closed circuit is approximately zero, a large direct current instantly flows from capacitor C1. This may burn out circuit components on the closed circuit.

[0024] Next, the power generating device 1 according to this embodiment will be described. Fig. 5 is a functional block diagram of the power generating device 1 according to this embodiment. As shown in this diagram, the power generating device 1 includes a protection circuit for short circuits in addition to the configuration of the power generating device 100 described above. That is, the power generating device 1 includes, in addition to the generator 10 and the power conversion circuit 21, a first shutoff circuit 23, a second shutoff circuit 24, a first monitoring circuit 25, and a second monitoring circuit 26 as protection circuits. As will be understood from the operation described below, the first monitoring circuit 25 is a circuit that detects inter-phase short circuits and ground faults in the generator 10, and the second monitoring circuit 26 is a circuit that detects intra-phase short circuits in the generator 10.

[0025] The first shutoff circuit 23 is provided between the output of the generator 10 and the input of the power conversion circuit 21. The first shutoff circuit 23 receives a control signal from the control unit 22 and electrically shuts off the electrical connection between the generator 10 and the power conversion circuit 21. This control signal is output from the control unit 22 in response to a first shutoff signal output from the first monitoring circuit 25 or a second shutoff signal output from the second monitoring circuit 26. Alternatively, the first shutoff signal or the second shutoff signal itself may function as the control signal. The first shutoff circuit 23 is composed of a semiconductor switch S1 provided in the U phase, a semiconductor switch S2 provided in the V phase, and a semiconductor switch S3 provided in the W phase. The semiconductor switches S1 to S3 are, for example, power semiconductors such as bidirectional thyristors, MOSFETs, and IGBTs.

[0026] The second shutoff circuit 24 is provided between each of the three-phase coils Lu, Lv, and Lw and the neutral point N. The second shutoff circuit 24 receives a control signal from the control unit 22 and electrically shuts off the electrical connection between the three-phase coils and the power conversion circuit 21. This control signal is output from the control unit 22 in response to a first shutoff signal output from the first monitoring circuit 25 or a second shutoff signal output from the second monitoring circuit 26. Alternatively, the first shutoff signal or the second shutoff signal itself may function as the control signal. Like the first shutoff circuit 23, the second shutoff circuit 24 is also configured by a semiconductor switch S4 provided in the U phase, a semiconductor switch S5 provided in the V phase, and a semiconductor switch S6 provided in the W phase. The semiconductor switches S4 to S6 are, for example, power semiconductors such as bidirectional thyristors, MOSFETs, or IGBTs.

[0027] 6 is a circuit diagram showing an example of the first monitoring circuit 25. As shown in this diagram, the first monitoring circuit 25 includes shunt resistors R1 to R3, isolation amplifiers ISO1 to ISO3, comparators CMP1 to CMP6, and an OR circuit OR1. The shunt resistors R1 to R3 operate (function) as a current sensor provided between the output of the generator 10 and the input of the power conversion circuit 21. The first monitoring circuit 25 monitors the output current flowing from the generator 10 to the power conversion circuit 21, and outputs a first shutoff signal when the absolute value of the output current exceeds a first predetermined value. The first predetermined value is set by the control unit 22 taking into consideration fluctuations in the rotational speed of the generator 10, noise, etc., and is output as a threshold voltage Vth1.

[0028] The first monitoring circuit 25 monitors the voltage corresponding to the output current obtained by the current sensor. For example, the first monitoring circuit 25 monitors the voltage of a shunt resistor R1 (R2, R3) inserted between the output of the generator 10 and the input of the power conversion circuit 21 to monitor the output current flowing from the generator 10 to the power conversion circuit 21.

[0029] The shunt resistor R1 is provided on the U-phase output path connecting the coil Lu and the power conversion circuit 21. The inputs of the isolation amplifier ISO1 are connected to both ends of the shunt resistor R1. The isolation amplifier ISO1 detects the voltage across the shunt resistor R1 and outputs the measured voltage to the negative input of the comparator CMP1 and the positive input of the comparator CMP2. A first predetermined threshold voltage Vth1 is applied to the positive input of the comparator CMP1. An inverted voltage of the threshold voltage Vth1 is applied to the negative input of the comparator CMP2. Therefore, when the current value through the shunt resistor R1 exceeds the absolute value of the current value corresponding to the threshold voltage Vth1, either the comparator CMP1 or the comparator CMP2 outputs an output signal indicating this to the OR circuit OR1.

[0030] Shunt resistor R2 is provided on the V-phase output path connecting coil Lv and power conversion circuit 21. The inputs of isolation amplifier ISO2 are connected to both ends of shunt resistor R2. Isolation amplifier ISO2 detects the voltage across shunt resistor R2 and outputs the measured voltage to the negative input of comparator CMP3 and the positive input of comparator CMP4. A first predetermined threshold voltage Vth1 is applied to the positive input of comparator CMP3. An inverted voltage of threshold voltage Vth1 is applied to the negative input of comparator CMP4. Therefore, when the current value through shunt resistor R2 exceeds the absolute value of the current value corresponding to threshold voltage Vth1, either comparator CMP3 or comparator CMP4 outputs an output signal indicating this to OR circuit OR1.

[0031] Shunt resistor R3 is provided on the W-phase output path connecting coil Lw and power conversion circuit 21. The inputs of isolation amplifier ISO3 are connected to both ends of shunt resistor R3. Isolation amplifier ISO3 detects the voltage across shunt resistor R1 and outputs the measured voltage to the negative input of comparator CMP5 and the positive input of comparator CMP6. A first predetermined threshold voltage Vth1 is applied to the positive input of comparator CMP5. An inverted voltage of threshold voltage Vth1 is applied to the negative input of comparator CMP6. Therefore, when the current value through shunt resistor R3 exceeds the absolute value of the current value corresponding to threshold voltage Vth1, either comparator CMP5 or comparator CMP6 outputs an output signal indicating this to OR circuit OR1.

[0032] The outputs of comparators CMP1-CMP6 are connected to the input of OR circuit OR1. Therefore, when the current value of any of shunt resistors R1-R3 exceeds the absolute value of the current value corresponding to threshold voltage Vth1, OR circuit OR1 outputs a signal of a level indicating this as a first shutoff signal to control unit 22. Control unit 22 receives the first shutoff signal from OR circuit OR1 and outputs a control signal to each of first shutoff circuit 23 and second shutoff circuit 24 to shut off the circuit.

[0033] The current sensor provided between the output of the generator 10 and the input of the power conversion circuit 21 is not limited to the shunt resistor described above. That is, the current sensor may be a magnetic sensor such as a Hall sensor. In either case, a voltage proportional to the current flowing between the generator 10 and the power conversion circuit 21 can be obtained.

[0034] FIG. 7 is a circuit diagram showing an example of the second monitoring circuit 26 according to this embodiment. As shown in this diagram, the second monitoring circuit 26 includes isolation amplifiers ISO7 to ISO9, comparators CMP13 and CMP14, and an OR circuit OR2. The second monitoring circuit 26 monitors the sum of the output voltages of the phases of the generator 10 (hereinafter referred to as the total voltage). The second monitoring circuit 26 outputs a second shutoff signal when the absolute value of the total voltage exceeds a second predetermined value. The second predetermined value is set by the control unit 22 taking into consideration fluctuations such as noise, and is output as a threshold voltage Vth2.

[0035] To measure the voltage of each phase, the second monitoring circuit 26 monitors, for example, the voltage at both ends (i.e., the output end and neutral end) of each of the coils Lu (Lv, Lw) that make up the three-phase coil. The output end of the coil, which is one of the ends of the coil, essentially functions as the output end of the generator 10. The other end of the coil, which is the neutral end of the coil, is connected to the neutral point N via the second shutoff circuit 24.

[0036] The isolation amplifier ISO7 detects the voltage across the coil Lu and outputs the measured voltage to the adder ADD1. If the voltage across the coil Lu is excessive, a voltage divider circuit (not shown) using resistors can be used to set the voltage to an appropriate value.

[0037] The isolation amplifier ISO8 detects the voltage value across the coil Lv and outputs the measured voltage value to the adder ADD1. If the voltage across the coil Lv is excessive, the voltage can be set to an appropriate voltage using a voltage divider circuit (not shown) that uses resistors.

[0038] The isolation amplifier ISO9 detects the voltage value across the coil Lw and outputs the measured voltage value to the adder ADD1. If the voltage across the coil Lw is excessive, the voltage can be set to an appropriate voltage using a voltage divider circuit (not shown) that uses resistors.

[0039] The adder ADD1 calculates the sum of the voltages output from the isolation amplifiers ISO7 to ISO9 and outputs the sum to the negative input of the comparator CMP13 and the positive input of the comparator CMP14. Meanwhile, the positive input of the comparator CMP13 is multiplied by a threshold voltage Vth2, which is a second predetermined value. Also, the negative input of the comparator CMP14 is multiplied by an inverted voltage of the threshold voltage Vth2.

[0040] When the output voltage of the adder ADD1 exceeds the absolute value of the threshold voltage Vth2, either the comparator CMP13 or the comparator CMP14 outputs an output signal at a level indicating that fact to the OR circuit OR2.

[0041] The voltage generated by the generator 10 is a pseudo three-phase sinusoidal AC voltage generated by PWM (pulse width modulation). If ripples caused by PWM are not taken into account, the voltages of each phase change with the same waveform, with a phase difference of 120°. Therefore, when the generator 10 is operating normally, the sum of the voltages of each phase is, in principle, zero. Therefore, the sum of the voltages appearing across the coils Lu, Lv, and Lw, i.e., the output voltage of the adder ADD1, is also, in principle, zero. Conversely, if the current waveforms of any of the U, V, and W phases are disturbed and the current balance is lost, the sum of the voltages appearing across the coils Lu, Lv, and Lw changes from zero. Therefore, the threshold voltage Vth2 is set, for example, to the maximum value of the expected fluctuations, such as ripples.

[0042] The outputs of comparators CMP13 and CMP14 are connected to the input of OR circuit OR2. Therefore, when the output voltage of adder ADD1 exceeds the absolute value of threshold voltage Vth2, OR circuit OR2 outputs a signal of a level indicating this to control unit 22 as a second shutoff signal. Upon receiving the second shutoff signal from OR circuit OR2, control unit 22 outputs control signals to first shutoff circuit 23 and second shutoff circuit 24, respectively, to shut off the circuits.

[0043] As shown by the dashed lines in Figure 7, the second monitoring circuit 26 may measure the voltage between the output terminal of the coil Lu (Lv, Lw) and the neutral point N instead of measuring the voltage across both ends of the coil Lu (Lv, Lw) to measure the voltage of each phase.

[0044] (Breakdown operation in case of short circuit within a phase) When an intra-phase short circuit occurs in the power generation device 1 according to this embodiment, the output voltage of the phase in which the intra-phase short circuit occurs drops. That is, the voltage of each phase in which the short circuit occurs drops below the voltage of each phase in which the short circuit does not occur.

[0045] As described above, the second monitoring circuit 26 monitors the sum of the output voltages of the phases of the generator 10. When an intra-phase short circuit occurs, the voltage of one of the coils Lu, Lv, and Lw decreases, causing the sum of the output voltages of the phases to increase or decrease from zero. When the absolute value of this fluctuation exceeds the threshold voltage Vth2, the OR circuit OR2 outputs a second shutoff signal to the control unit 22.

[0046] Upon receiving the second shutoff signal from OR circuit OR2, control unit 22 outputs a control signal to each of first shutoff circuit 23 and second shutoff circuit 24 to shut off the circuit. First shutoff circuit 23 turns off semiconductor switches S1 to S3 upon receiving the control signal from control unit 22. Similarly, second shutoff circuit 24 turns off semiconductor switches S4 to S6 upon receiving the control signal from control unit 22. This quickly and completely shuts off the electrical connection between generator 10 and power conversion circuit 21, preventing further damage to power generation device 1 due to overcurrent.

[0047] (Breakdown operation in the event of a phase-to-phase short circuit or ground fault) In the power generation device 1 according to this embodiment, when a phase-to-phase short circuit or a ground fault occurs, the output current of the phase in which the phase short circuit or ground fault occurs increases. That is, the current of the phase in which the short circuit occurs increases more than the current of the phase in which the short circuit does not occur. This increase in output current also increases the voltage of the shunt resistor provided in the phase in which the short circuit occurs.

[0048] As described above, the first monitoring circuit 25 monitors the output current flowing from the generator 10 to the power conversion circuit 21 using the voltages of the shunt resistors R1 to R3. When a phase-to-phase short circuit occurs, the voltage of one of the shunt resistors R1 to R3 increases. When this fluctuation value exceeds the threshold voltage Vth1, the OR circuit OR1 outputs a first shutoff signal to the control unit 22.

[0049] Upon receiving the first shutoff signal from OR circuit OR1, control unit 22 outputs a control signal to each of first shutoff circuit 23 and second shutoff circuit 24 to shut off the circuit. First shutoff circuit 23 turns off semiconductor switches S1 to S3 upon receiving the control signal from control unit 22. Similarly, second shutoff circuit 24 turns off semiconductor switches S4 to S6 upon receiving the control signal from control unit 22. This quickly and completely shuts off the electrical connection between generator 10 and power conversion circuit 21, making it possible to prevent further damage to power generation device 1 due to overcurrent.

[0050] The power generator 1 according to this embodiment can be applied even in an environment where the rotation of the rotor cannot be immediately stopped, i.e., power generation cannot be immediately stopped. An example of a power generator suitable for such an environment is an aircraft generator. The power generator installed on an aircraft employs a wound field synchronous generator (WFSG) that can stop excitation, but the aircraft does not have a drive force interruption mechanism, such as a clutch, that interrupts the drive force from the turbine that drives the generator. Therefore, the rotor of the generator continues to rotate as long as the turbine is rotating. Furthermore, the generator installed on an aircraft is cooled using cooling oil. If the generator generates excessive heat due to a short circuit or other problem within the generator, power generation must be stopped to prevent the generator from catching fire and the cooling oil from igniting.

[0051] On the other hand, the power generation device 1 according to this embodiment does not use a filter element or filter circuit such as an inductor to detect abnormal current. Therefore, the power supply can be cut off in a short time (for example, within 200 μs). Therefore, it can be used in the above-mentioned environment.

[0052] (Variation) 8 is a circuit diagram showing another example of the first monitoring circuit 25 according to this embodiment. As shown in this figure, the first monitoring circuit 25 may monitor the voltage of each pair of switching elements to monitor the output current flowing from the generator 10 to the power conversion circuit 21. That is, the first monitoring circuit 25 may monitor the voltage between the two terminals through which the output current passes in each of all of the switching elements Tr1 to Tr6. The circuit configuration from the detection of each voltage to the OR circuit via the isolation amplifier and comparator is the same as that shown in FIG. 6. In this modification, the shunt resistors R1 to R3 can be omitted, allowing for faster cutoff operation.

[0053] The generator 10 according to this embodiment is not limited to a permanent magnet synchronous generator, and may be another type of generator. The protection of the power generating device according to this embodiment is more effective for generators that cannot stop generating power through rotor rotation when an abnormality occurs in the generator. However, it is possible to protect power generating devices equipped with other generators, such as electromagnet synchronous generators.

[0054] Furthermore, the present disclosure is not limited to the above-described embodiments, but is defined by the claims, and includes all modifications within the meaning and scope equivalent to the claims.

Claims

1. a generator having a stator including three-phase coils; a power conversion circuit that converts AC power output from the generator into DC power; a first interrupter circuit provided between an output of the generator and an input of the power conversion circuit; a second interrupter circuit provided between the three-phase coil and a neutral point; a first monitoring circuit that monitors an output current flowing from the generator to the power conversion circuit and outputs a first shutoff signal when an absolute value of the output current exceeds a first predetermined value; a second monitoring circuit that monitors a total value of the output voltages of the phases of the generator and outputs a second shutoff signal when the absolute value of the total value exceeds a second predetermined value; Equipped with the first shutoff circuit electrically shuts off a connection between the generator and the power conversion circuit in response to output of the first shutoff signal or the second shutoff signal; The second shutoff circuit electrically shuts off the connection between the three-phase coils and the neutral point in response to the output of the first shutoff signal or the second shutoff signal. Power generation equipment.

2. the first monitoring circuit monitors a voltage corresponding to the output current, the voltage being obtained by a current sensor provided between the output of the generator and the input of the power conversion circuit, in order to monitor the output current; The power generating device according to claim 1 .

3. the power conversion circuit includes a pair of switching elements functioning as rectifying elements for each phase; the first monitoring circuit monitors the voltages of the pair of switching elements to monitor the output current; The power generating device according to claim 1 .

4. The generator is a permanent magnet synchronous generator. The power generating device according to claim 1 .

5. The output voltage is the voltage across each coil of the three-phase coil. The power generating device according to claim 1 .

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