JP2021016260A - Synchronous generator control device and power supply system including the same - Google Patents

Abstract

To provide a synchronous motor control device and a power supply system including the same, which can achieve load sharing of electric power between a synchronous generator and an electricity storage device with a simple and inexpensive configuration.SOLUTION: A power supply system includes a synchronous generator of a winding field magnet type, a diode rectifier that rectifies first AC power output from the synchronous generator into DC power, an inverter that converts the DC power into second AC power and supplies the second AC power to a power load connected to an AC side, a DC wiring that connects a DC side of the diode rectifier to a DC side of the inverter, and an electricity storage device that is directly connected to the DC wiring. A control device of the synchronous generator is configured to control the power supplied by the synchronous generator by manipulating a field voltage of the synchronous generator.SELECTED DRAWING: Figure 1

Description

The present invention relates to a control device for a synchronous generator and a power supply system including the control device.

As a power supply system installed in a ship or a railroad, a series hybrid system including a generator and a power storage device such as a battery is often adopted due to its high efficiency or high degree of control freedom (for example). See Patent Document 1 below).

Conventional hybrid systems include a converter that converts AC power output from a generator (synchronous generator) connected to a prime mover such as an engine to DC power, and a converter that converts DC power to AC power for loads such as motors. It is provided with an input inverter, a power storage device connected to a DC unit between the converter and the inverter, and a control device for sharing the load between the generator and the power storage device.

Japanese Unexamined Patent Publication No. 2008-99461

In the above-mentioned conventional configuration, in order to share the power load between the generator and the power storage device, the converter is configured as, for example, a PWM converter composed of a plurality of switching elements capable of PWM control, and is controlled. The device switches and controls the converter. Alternatively, in addition to or instead of this, a DC-DC converter is provided between the power storage device and the DC unit, and the control device switches and controls the DC-DC converter. In this way, the power of the engine or the like is converted into electric power, the load is driven by the electric power, and the excess or deficiency of the electric power is supplemented by the electric power of the power storage device.

As described above, the conventional configuration requires complicated and expensive equipment such as a PWM converter or a DC-DC converter, which causes a problem that the system becomes complicated and expensive.

The present invention solves the above-mentioned problems, and includes a synchronous motor control device capable of realizing power load sharing between the synchronous generator and the power storage device with a simple and inexpensive configuration, and a control device thereof. The purpose is to provide a power supply system.

The control device of the synchronous generator according to one aspect of the present invention is a control device of the synchronous generator in the power supply system, and the power supply system is a winding field type synchronous generator and the synchronous power generation. A diode rectifier that rectifies the first AC power output from the machine into DC power, and an inverter that converts the DC power into second AC power and supplies the second AC power to the power load connected to the AC side. A DC wiring that connects the DC side of the diode rectifier and the DC side of the inverter, and a power storage device that is directly connected to the DC wiring are provided, and the control device is supplied by the synchronous generator. The power is configured to be controlled by manipulating the field voltage of the synchronous generator. The control device adjusts the load sharing ratio between the synchronous generator and the power storage device with respect to the electric power load by controlling the electric power supplied by the synchronous motor.

According to the above configuration, a relatively inexpensive diode rectifier is provided between the synchronous generator and the DC wiring, and the power storage device is directly connected to the DC wiring. The electric power supplied by the synchronous generator is controlled by manipulating the field voltage of the synchronous generator. As a result, the load sharing ratio between the synchronous generator and the power storage device with respect to the power load is adjusted. Therefore, it is possible to eliminate the need for complicated equipment (PWM converter, DC-DC converter) including a plurality of switching elements, and while realizing a simple and inexpensive configuration, power can be supplied between the synchronous generator and the power storage device. Load sharing can be realized.

The control device determines whether or not the voltage or charge rate of the power storage device is within a predetermined reference range, and when the voltage or charge rate of the power storage device is within the reference range, the power storage device The field voltage of the synchronous generator may be manipulated so that the first current flowing through the synchronous generator becomes zero constantly. According to this, when the voltage or charge rate of the power storage device is within a predetermined reference range capable of sufficiently charging the power storage device (power absorption) and discharging from the power storage device (power supply). When a load fluctuation occurs, a power storage device that is more responsive than a synchronous generator supplies or absorbs most of the power change to the power load according to the load fluctuation. At this time, the field voltage of the synchronous generator is changed so that the first current flowing through the power storage device is constantly set to 0. As a result, in the steady state after the load fluctuation, all the fluctuation of the power load is covered by (the fluctuation) of the electric power supplied from the synchronous generator. Therefore, even if there is no device including a switching element that requires complicated control between the synchronous generator and the power storage device, it is possible to easily realize the power load sharing between the synchronous generator and the power storage device.

The control device is a field of the synchronous generator so that a current discharged from the power storage device flows as the first current when the voltage or charge rate of the power storage device exceeds the upper limit value of the reference range. It may be configured to manipulate the voltage. Further, the control device of the synchronous generator causes the current for charging the power storage device to flow as the first current when the voltage or charge rate of the power storage device falls below the lower limit of the reference range. It may be configured to manipulate the field voltage. According to this, when the voltage or charge rate of the power storage device is out of the reference range and charging to the power storage device or discharge from the power storage device is required, the first current corresponding to the charge or discharge flows to the power storage device. The field voltage of the synchronous generator is changed to. As a result, the voltage or charge rate of the power storage device can be returned to the reference range by charging or discharging the power storage device while supplying power to the power load.

The control device may stop the synchronous generator when the voltage or charge rate of the power storage device exceeds the upper limit value of the reference range. According to this, when the voltage or charge rate of the power storage device is out of the standard range and discharge from the power storage device is required, the synchronous generator is stopped, so that the power storage device supplies power to the power load. Therefore, the voltage or charge rate of the power storage device can be returned within the reference range. Furthermore, fuel consumption can be reduced by stopping the prime mover that drives the synchronous generator.

After the synchronous generator is stopped, the control device operates the synchronous generator when the voltage or charge rate of the power storage device becomes equal to or less than a predetermined start reference value smaller than the upper limit value of the reference range. May be restarted. This makes it possible to prevent the synchronous generator from being frequently started and stopped when the voltage or charge rate of the power storage device fluctuates near the upper limit of the reference range.

The control device includes a current target value generator that generates a current target value of the first current from a predetermined power storage device parameter including a voltage or a charge rate of the power storage device, and the first measurement device measured from the current target value. A first current deviation calculation unit that calculates the first current deviation obtained by subtracting the current, and a field voltage target value generation unit that generates a field voltage target value of the synchronous generator based on the first current deviation. It may be included.

The current target value generation unit determines whether or not the voltage or charge rate of the power storage device is within a predetermined reference range, and when the voltage or charge rate of the power storage device is within the reference range, It may be configured to set the current target value to 0.

The field voltage target value generation unit is configured to generate the field voltage target value based on a transmission function having a predetermined first coefficient from the first current deviation, and the first coefficient is the first coefficient. The convergence time until the current deviation converges from a predetermined value to 0 may be set to be a convergence time that matches the response performance of the prime mover that drives the synchronous generator. According to this, the rate of change of the field voltage can be matched to the response performance of the prime mover that drives the synchronous generator, and even if a sudden change in the power load occurs, the prime mover is prevented from being overloaded. can do.

The field voltage target value generation unit includes a first target value generation unit that generates a generator current target value based on a transmission function having a predetermined first coefficient from the first current deviation, and the generator current target value generation unit. The field voltage target value is set based on the second current deviation calculation unit that generates the second current deviation obtained by subtracting the measured generator current from the second current deviation, and the transmission function having a predetermined second coefficient from the second current deviation. The second target value generation unit to be generated may be included. According to this, the target value of the generator current flowing through the synchronous generator is generated from the first current deviation, and the field voltage target value is generated from the deviation between the generator current target value and the current generator current. .. As a result, the generator current is used as one of the control parameters, so that the control system can be further stabilized. Further, according to this configuration, since the generator current is used as one of the control parameters, it becomes easy to set a limit on the generator current. Therefore, it is possible to prevent an unintended overcurrent from flowing to the synchronous generator due to load fluctuation.

The power supply system according to another aspect of the present invention includes a winding field type synchronous generator, a diode rectifier that rectifies the first AC power output from the synchronous generator into DC power, and the DC power. To the second AC power and supply the second AC power to the power load connected to the AC side, the DC wiring connecting the DC side of the diode rectifier and the DC side of the inverter, and the above. A power storage device directly connected to a DC wiring and a control device for controlling the synchronous generator are provided, and the control device operates the power supplied by the synchronous generator and the field voltage of the synchronous generator. By doing so, it is configured to control.

According to the above configuration, a relatively inexpensive diode rectifier is provided between the synchronous generator and the DC wiring, and the power storage device is directly connected to the DC wiring. The electric power supplied by the synchronous generator is controlled by manipulating the field voltage of the synchronous generator. As a result, the load sharing ratio between the synchronous generator and the power storage device with respect to the power load is adjusted. Therefore, it is possible to eliminate the need for complicated equipment (PWM converter, DC-DC converter) including a plurality of switching elements, and while realizing a simple and inexpensive configuration, power can be supplied between the synchronous generator and the power storage device. Load sharing can be realized.

According to the present invention, it is possible to realize the power load sharing between the synchronous generator and the power storage device with a simple and inexpensive configuration.

FIG. 1 is a block diagram showing a schematic configuration of a power supply system according to an embodiment of the present invention. FIG. 2 is a diagram showing an arrangement example of a plurality of diode elements constituting the diode rectifier shown in FIG. FIG. 3 is a diagram showing an arrangement example of a plurality of switching elements constituting the inverter shown in FIG. FIG. 4 is a schematic view showing an example of a control block of the control device shown in FIG. FIG. 5 is a graph showing the result of the control simulation of the synchronous generator in the present embodiment. FIG. 6 is a graph showing the result of the control simulation of the synchronous generator in the present embodiment. FIG. 7 is a graph showing the result of the control simulation of the synchronous generator in the present embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following, the same reference numerals are given to elements having the same or the same function throughout all the figures, and duplicate description thereof will be omitted.

FIG. 1 is a block diagram showing a schematic configuration of a power supply system according to an embodiment of the present invention. The electric power supply system 1 in the present embodiment includes a synchronous generator 3 that generates electric power from a prime mover 2 such as an engine, and a power storage device 4 as electric power supply sources.

The synchronous generator 3 is a winding field type synchronous generator, and is configured so that the AC power output from the synchronous generator 3 changes depending on the field voltage _Vf applied to the exciting portion 3a. .. The power storage device 4 is configured to be capable of charging and discharging. The power storage device 4 is, for example, a secondary battery or a capacitor.

The power supply system 1 includes a diode rectifier 5 that rectifies the first AC power output from the synchronous generator 3 into DC power, and an inverter 6 that converts DC power into second AC power. A power load 7 such as a motor is connected to the output (AC side) of the inverter 6. As a result, the second AC power is supplied to the power load 7. The power load 7 may include, for example, a plurality of propulsion motors.

The power storage device 4 is directly connected to the DC wiring 8 that connects the DC side of the diode rectifier 5 and the DC side of the inverter 6.

FIG. 2 is a diagram showing an arrangement example of a plurality of diode elements constituting the diode rectifier shown in FIG. As shown in FIG. 2, the diode rectifier 5 includes a plurality of (six) diode elements 9. In the diode rectifier 5, a pair of diode element trains 10 in which two diode elements 9 are connected in series are connected in parallel in three pairs.

The wiring of each phase in the three-phase AC wiring 11 from the synchronous generator 3 is connected to each of the connection points of the two diode elements 9 in each diode element row 10. One end (cathode side end) and the other end (anode side end) of the diode rectifier 5 are connected to the DC wiring 8.

FIG. 3 is a diagram showing an arrangement example of a plurality of switching elements constituting the inverter shown in FIG. As shown in FIG. 3, the inverter 6 includes a plurality of (six) switch elements 12 and a plurality of (six) freewheeling diodes 13 connected in parallel to each switch element 12.

In the inverter 6, a pair of switch element trains 14 in which two switch elements 12 are connected in series are connected in parallel in three pairs. The wiring of each phase in the three-phase AC wiring 15 connected to the power load 7 is connected to each of the connection points of the two switch elements 12 in each switch element row 14. One end and the other end of the inverter 6 are connected to the DC wiring 8.

The power supply system 1 includes a control device 16 that controls a synchronous generator 3. The control device 16 sets the field voltage target value V _f0 in the manner described later and outputs the field voltage target value to the synchronous generator 3. The control device 16 is composed of, for example, a computer such as a microcontroller equipped with a calculation unit such as a CPU, a ROM, a RAM, and the like. The control device 16 that realizes the control mode described later may be configured as one function of the automatic voltage regulator (AVR) provided in the exciter of the synchronous machine, or may be configured as a control device different from the AVR. You may.

The control device 16 is configured to control the electric power supplied by the synchronous generator 3 by operating the field voltage V _f of the synchronous generator 3. By operating the field voltage V _f of the synchronous generator 3, the electric power supplied by the synchronous generator 3 to the electric power load 7 is controlled, and the load is shared between the synchronous generator 3 and the power storage device 4 with respect to the electric power load 7. The proportion is adjusted. For this purpose, the control device 16 acquires the first current I _bat flowing through the power storage device 4. In the present specification, the first current I _bat is in the positive direction in the direction out of the power storage device 4 (the direction in which the current discharged from the power storage device 4 flows).

Further, the control device 16 acquires a predetermined power storage device parameter including the voltage V _bat or charge rate SOC (State Of Charge) of the power storage device 4 and the temperature T _bat by measurement. Further, the control device 16 acquires the generator current flowing through the synchronous generator 3 by measurement. In the present embodiment, the control device 16 measures and acquires the generator current (current flowing through the DC wiring 8) I _{gen_dc} after being converted to direct current by the diode rectifier 5 as the generator current. Instead of this, the control device 16 may acquire an alternating current before being converted to direct current by the diode rectifier 5 as a generator current.

FIG. 4 is a schematic view showing an example of a control block of the control device shown in FIG. As shown in FIG. 4, the control device 16 includes a current target value generation unit 17, a current deviation calculation unit 18, and a field voltage target value generation unit 19 as control blocks.

Current target value generating unit 17 generates a current target value _{I BAT0} of the first current _{I bat} flowing the electric storage device parameter _V bat, _SOC, from _{T bat} storage device 4. The current deviation calculation unit 18 calculates the first current deviation ΔI _bat by subtracting the measured first current I _bat from the current target value I _bat0 . The current deviation calculation unit 18 is composed of, for example, a subtractor. The field voltage target value generation unit 19 generates the field voltage target value V _f0 of the synchronous generator 3 based on the first current deviation ΔI _bat .

For example, the controller 16 determines whether or not within the reference range A that the SOC of power storage device 4 is predetermined, to generate a current target value I _BAT0 of the first current I _bat accordingly. Controller 16, when the charging rate SOC of power storage device 4 is within the reference range A, the current target value _{I BAT0} of the first current _{I bat} is set to 0. Field voltage target value generating unit 19 generates a field voltage target value _{V f0} such that the first current _{I bat} to the current target value _{I bat0} = 0.

As a result, the generated field voltage target value V _f0 is applied to the synchronous generator 3 as the field voltage V _f , and the synchronous generator 3 outputs the corresponding AC power. In this way, the control device 16 is a synchronous generator so that the first current I _bat flowing through the power storage device 4 is constantly set to 0 when the charge rate SOC of the power storage device 4 is within the reference range A. It is configured to operate the field voltage V _f .

The reference range A is set as a range in which the power storage device 4 can be sufficiently charged (power absorption) and the power storage device 4 can be sufficiently discharged (power supply). For example, the reference range A is set to a range in which the charge rate SOC is 30% or more and 70% or less. Instead of this, when the reference range A based on the voltage V _bat of the power storage device 4 is used, the voltage range corresponding to the range of the charge rate SOC can be set as the reference range A. That is, when the voltage _{V bat} of power storage device 4 when the SOC is 30% and _{V 30,} and _{V 70} the voltage _{V bat} of power storage device 4 when the SOC is 70%, reference range A _Can be set to V ₃₀ ≤ A ≤ V ₇₀ . Also in the following description, the charge rate SOC of the power storage device 4 can be appropriately read as the voltage V _bat of the power storage device 4.

Further, the control unit 16, when the upper limit value (e.g., the charging rate SOC of 70%) of the charging rate SOC is a reference range A of power storage device 4 exceeds a current target value _{I BAT0} of the first current _{I bat} predetermined Set to a positive fixed value C (> 0). Field voltage target value generating unit 19 generates a field voltage target value _{V f0} such that the first current _{I bat} to the current target value _{I bat0 = C (> 0)} .

As a result, the generated field voltage target value V _f0 is applied to the synchronous generator 3 as the field voltage V _f , and the synchronous generator 3 outputs the corresponding AC power. In this way, the control device 16 is a synchronous generator so that when the charge rate SOC of the power storage device 4 exceeds the upper limit value of the reference range A, the current discharged from the power storage device 4 flows as the first current I _bat. It is configured to operate the field voltage V _{f of} 3.

Further, the control device 16 has a current target value I of the first current I _bat when the voltage V _bat or the charge rate SOC of the power storage device 4 falls below the lower limit value of the reference range A (for example, the charge rate SOC is 30%). _bat0 is set to a predetermined negative fixed value −C (<0). Field voltage target value generating unit 19 generates a field voltage target value _{V f0} as to the first current _{I bat} current target value _{I bat0 = -C (<0)} .

As a result, the generated field voltage target value V _f0 is applied to the synchronous generator 3 as the field voltage V _f , and the synchronous generator 3 outputs the corresponding AC power. As described above, when the voltage V _bat or the charge rate SOC of the power storage device 4 falls below the lower limit of the reference range A, the control device 16 causes the current to charge the power storage device 4 to flow as the first current I _bat. , It is configured to operate the field voltage V _f of the synchronous generator 3.

When the voltage V _bat or charge rate SOC of the power storage device 4 falls outside the reference range A and then the voltage or charge rate of the power storage device 4 reaches a predetermined return reference value, the control device 16 stores power. The control returns to the control of operating the field voltage V _f of the synchronous generator so that the first current I _bat flowing through the device 4 is constantly set to 0. For example, the return reference value is set to a value lower than the upper limit value of the reference range A and a value higher than the lower limit value of the reference range A. For example, when the upper limit value of the reference range A is 70% and the lower limit value is set to 30%, the return reference value is set to 50%. When the voltage V _bat or charge rate SOC of the power storage device 4 exceeds the upper limit value of the reference range A, the recovery reference value, and when the voltage V _bat or charge rate SOC of the power storage device 4 falls below the lower limit value of the reference range A. The value may be different from the return reference value of.

Further, the control unit 16 determines whether or not within the reference temperature range B1 temperature _{T bat} of power storage device 4 is predetermined, to generate a current target value _{I BAT0} of the first current _{I bat} accordingly .. For example, the control unit 16, when the temperature _{T bat} of power storage device 4 is the reference temperature range B1 outside, to limit the magnitude of the current target value _{I BAT0} of the first current _{I bat.}

For example, when the temperature T _bat of the power storage device 4 is outside the reference temperature range B1, the control device 16 sets the maximum value of the current target value I _{bat 0} to D (<C). As a result, when charging the power storage device 4 or discharging from the power storage device 4, the magnitude of the current target value I _bat0 is limited to the current value D smaller than C (in the case of charging, the current target value I _{bat0). Changes} from C to D, and in the case of discharge, the current target value I _bat0 changes from -C to -D). The control device 16, when the temperature _{T bat} of power storage device 4 is within the reference temperature range B1, may not restrict the current target value _{I BAT0.}

Further, the control device 16 may determine whether or not the temperature T _bat of the power storage device 4 is outside the permissible temperature range B2 wider than the reference temperature range B1. For example, the control unit 16, when the temperature _{T bat} of power storage device 4 is the allowable temperature range B2 outside, the current target value _{I BAT0} of the first current _{I bat,} even 0 regardless of the SOC of power storage device 4 Good. The temperature T _bat of the power storage device 4 may not be included in the power storage device parameter (the above limitation by the temperature T _bat may not be applied).

According to the above configuration, a relatively inexpensive diode rectifier 5 is provided between the synchronous generator 3 and the DC wiring 8, and the power storage device 4 is directly connected to the DC wiring 8. The electric power supplied by the synchronous generator 3 is controlled by operating the field voltage V _f of the synchronous generator 3. As a result, the load sharing ratio between the synchronous generator 3 and the power storage device 4 with respect to the power load 7 is adjusted. Therefore, it is possible to eliminate the need for complicated equipment (PWM converter, DC-DC converter) including a plurality of switching elements, and while realizing a simple and inexpensive configuration, between the synchronous generator 3 and the power storage device 4. It is possible to realize the load sharing of electric power.

Further, according to the above configuration, the voltage V _bat or the charge rate SOC of the power storage device 4 can sufficiently charge the power storage device 4 (power absorption) and discharge the power storage device 4 (power supply). If a load fluctuation occurs while the power is within the reference range A, the power storage device 4 having a better response than the synchronous generator 3 absorbs most of the surplus power or most of the insufficient power is powered according to the load fluctuation. It is supplied to the load 7. This is because the internal resistance of the power storage device 4 is generally smaller than the winding impedance of the synchronous generator 3. Then, when such a load fluctuation occurs, the field voltage V _f of the synchronous generator 3 is changed so that the first current I _bat flowing through the power storage device 4 is constantly set to 0.

As a result, in the steady state after the load fluctuation, all the fluctuations of the power load 7 are covered by (the fluctuations) of the electric power supplied from the synchronous generator 3. Therefore, even if there is no device including a switching element that requires complicated control between the synchronous generator 3 and the power storage device 4, the power load sharing between the synchronous generator 3 and the power storage device 4 can be easily realized. be able to.

Further, when the voltage V _bat or the charge rate SOC of the power storage device 4 is out of the reference range A and the power storage device 4 needs to be charged or discharged from the power storage device 4, the first current I _bat corresponding to the charge or discharge is required. The field voltage V _f of the synchronous generator 3 is changed so that the current flows through the power storage device 4. As a result, the voltage or charge rate of the power storage device 4 can be returned to the reference range A by charging or discharging the power storage device 4 while supplying power to the power load 7.

Hereinafter, a more specific configuration of the field voltage target value generation unit 19 will be described. In the present embodiment, the field voltage target value generation unit 19 includes a first target value generation unit 20, a second current deviation calculation unit 21, and a second target value generation unit 22.

The first target value generation unit 20 generates the generator current target value I _{gen 0} from the first current deviation ΔI _bat based on the transfer function G ₁ (s) having a predetermined first coefficient. The first target value generation unit 20 is configured to determine the control waveform of the generator current I _{gen_dc} (field voltage V _f ) based on the first current I _bat . The first target value generation unit 20 is configured as, for example, a PI controller. In this case, the transfer function G ₁ (s) is expressed as G ₁ (s) = K _p1 (1 + 1 / _Ti1 s). Here, K _p1 is the first proportional gain, and _{Ti 1} is the first integration time.

The second current deviation calculation unit 21 generates a second current deviation ΔI _gen by subtracting the measured generator current I _{gen_dc} from the generator current target value I _gen0 . The second target value generation unit 22 generates the field voltage target value V _f0 from the second current deviation ΔI _gen based on the transfer function G ₂ (s) having a predetermined second coefficient. The second target value generation unit 22 is also configured as, for example, a PI controller. In this case, the transfer function G ₂ (s) is expressed as G ₂ (s) = K _p2 (1 + 1 / _Ti2 s). Here, K _p2 is the second proportional gain, and _Ti 2 is the second integration time.

According to this, the generator current target value I _gen0 is generated as the target value of the generator current I _{gen_dc} flowing from the first current deviation ΔI _bat to the synchronous generator 3, and the generator current target value I _gen0 and the current power generation are generated. The field voltage target value V _f0 is generated from the deviation ΔI _gen from the machine current I _{gen_dc} . As a result, the generator current I _{gen_dc} is used as one of the control parameters, so that the control system can be further stabilized.

Further, according to this configuration, since the generator current I _{gen_dc} is used as one of the control parameters, it becomes easy to set a limit on the generator current I _{gen_dc} . For example, the first target value generation unit 20 may include a limiter (limiter) that limits the generator current target value I _{gen 0} generated based on the transfer function G ₁ (s) to a predetermined current range. This makes it possible to prevent an unintended overcurrent from flowing to the synchronous generator 3 due to load fluctuations.

The first coefficient in the first target value generation unit 20 is the convergence time until the first current deviation ΔI _bat converges from a predetermined value to 0, and the convergence time according to the response performance of the prime mover 2 driving the synchronous generator 3. Can be set to be. When the transfer function G ₁ (s) contains a plurality of coefficients that contribute to the convergence time, one of the coefficients may be adjusted as described above, and two or more of the plurality of coefficients are described above. It may be adjusted as follows.

In this embodiment, the transfer function _G 1 (s) is, as an available coefficient as the first coefficient, and includes a first proportional gain _{K p1} and the first integration time _{T i1.} That is, in the first proportional gain K _p1 and / or the first integration time _Ti1 in the first target value generation unit 20, the convergence time until the first current deviation ΔI _bat converges from a predetermined value to 0 is the synchronous generator 3 The convergence time may be set to match the response performance of the prime mover 2 that drives the motor 2. For example, increasing the first proportional gain K _p1 shortens the convergence time, and decreasing the first proportional gain K _p1 increases the convergence time. Further, for example, the convergence time is shortened by reducing the first integration time T _i1, convergence time becomes longer by increasing the first integration time T _i1.

According to this, the response (speed change) of the generator current I _{gen_dc} at the time of load fluctuation can be matched with the response performance of the prime mover 2 for driving the synchronous generator 3. As a result, the load fluctuation on the prime mover 2 connected to the synchronous generator 3 becomes gentle with respect to the fluctuation of the power load. Therefore, the fuel efficiency of the prime mover 2 can be improved. Further, when the prime mover 2 is a gas engine or the like, the emission of graphite can be suppressed. Further, by adjusting the convergence time so that the speed change of the generator current I _{gen_dc} is within the limit range of the output change of the prime mover 2, the prime mover 2 can be prevented from tripping even if the power load 7 suddenly changes. Can be prevented.

The convergence time can also be changed by changing the second coefficient (second proportional gain K _p2 and / or second integration time _Ti 2) in the second target value generation unit 22. However, by setting the convergence time using the first proportional gain K _p1 and / or the first integration time _Ti1 in the first target value generation unit 20, the convergence of the first current I _bat with respect to the first current deviation ΔI _bat . You can set the time more directly.

[simulation result]
5 to 7 are graphs showing the results of the control simulation of the synchronous generator according to the present embodiment. FIG. 5 is a graph showing changes over time in various currents and voltage values when the charge rate SOC of the power storage device 4 is within the reference range A (30% to 70%). In FIG. 5, the graph (5a) is a graph of the DC voltage in the DC wiring 8. Graph (5b) is a graph of the first current _{I bat} and the current target value _{I BAT0.} The graph (5c) is a graph of the generator current I _{gen_dc} and the generator current target value I _{gen 0} . The graph (5d) is a graph of the field voltage V _f . The graph (5e) is a graph _{showing the} load current I _load flowing through the power load 7 together with the generator current I _{gen_dc} and the first current I _bat .

In the simulation shown in FIG. 5, as shown in the graph (5d), the synchronous generator 3 (motor 2) is started at the start of the simulation, and the load current I _{load gradually} changes from 0 to 200 A 2 seconds after the start ( It is simulating the case where the load current I _{load gradually} returns to the original 0 6 seconds after the start (stepwise).

When the load current increases 2 seconds after the start, as shown in the graph (5b), the power storage device 4 having a better response than the synchronous generator 3 supplies the power load 7 with insufficient power according to the load fluctuation. 1 current I _bat instantly rises to the discharge side (positive direction). As a result, as shown in the graph (5d), the control device 16 increases the field voltage V _f of the synchronous generator 3 so that the first current I _bat is constantly set to 0 (returned). As a result, as shown in the graph (5c), the generator current I _{gen_dc} starts to increase later than the rise of the first current I _bat . At this time, the generator current I _{gen_dc} increases based on PI control.

As the generator current I _{gen_dc} starts to increase, the first current I _bat decreases, and when the first current I _bat becomes 0, it is settled. As a result, as shown in the graph (5e), all the electric power supplied to the electric power load 7 is covered by the electric power supplied from the synchronous generator 3.

When the load current decreases 6 seconds after the start, as shown in the graph (5b), the first current I _bat so that the power storage device 4 having a better response than the synchronous generator 3 absorbs the surplus power according to the load fluctuation. Instantly rises to the charging side (negative direction). As a result, as shown in the graph (5d), the control device 16 reduces the field voltage V _f of the synchronous generator 3 so that the first current I _bat is constantly set to 0 (returned). As a result, as shown in the graph (5c), the generator current I _{gen_dc} starts to decrease behind the rising of the first current I _{bat in} the negative direction. At this time, the generator current I _{gen_dc} decreases based on PI control.

As the generator current I _{gen_dc} starts to decrease, the first current I _bat decreases (approaches 0), and when the first current I _bat becomes 0, it is settled. As a result, as shown in the graph (5e), all the electric power supplied to the electric power load 7 is covered by the electric power supplied from the synchronous generator 3.

As described above, according to the graph of FIG. 5, when the load fluctuation occurs when the charge rate SOC of the power storage device 4 is within the reference range A by this simulation, the power storage is more responsive than the synchronous generator 3. The power supply system according to the present embodiment is that the apparatus 4 responds to the load fluctuation, and then the power after the load fluctuation is covered by the synchronous generator 3 due to the change in the field voltage V _f of the synchronous generator 3. It is shown to be realized by 1.

FIG. 6 is a graph showing changes over time in various current values, voltage values, and charge rates when the charge rate SOC of the power storage device 4 is less than the lower limit value (30%) of the reference range A. In FIG. 6, the graph (6a) is a graph of the DC voltage in the DC wiring 8. The graph (6b) is a graph of the charge rate SOC of the power storage device 4. Graph (6c) is a graph of the first current _{I bat} and the current target value _{I BAT0.} The graph (6d) is a graph showing the load current I _load flowing through the power load 7 together with the generator current I _{gen_dc} .

In the simulation shown in FIG. 6, as shown in the graph (6d), the synchronous generator 3 (motor 2) is started at the start of the simulation, and the load current gradually increases (ramp function) from 2 seconds after the start. Simulates the case.

At the start, the charge rate SOC of the power storage device 4 is within the reference range A (30% or more and 70% or less). When the load current I _load gradually increases from 2 seconds after the start, the power storage device 4 responds to the load fluctuation and the first current I _bat rises as in the simulation shown in FIG. 5 (graph (6c)). Along with this, the control device 16 increases the field voltage V _f of the synchronous generator 3 so that the first current I _bat is constantly set to 0 (returned).

However, since the load current continues to increase, the current (first current) I _bat discharged from the power storage device 4 continues to increase without turning to decrease, and as a result, as shown in the graph (6b), the power storage device 4 Charge rate SOC continues to decline. At this time, as shown in the graph (6d), the generator current I _{gen_dc} also continues to increase, but _changes (increases) with a current value that is less than the load current by the burden of the first current I _bat due to the response delay. ..

When the charge rate SOC reaches 30%, which is the lower limit of the reference range A, within 5.4 seconds from the start, the control device 16 sets the current target value I _{bat 0} of the first current I _bat to a predetermined negative fixed _value-. Set to C (<0) (graph (6c)). In this simulation, the predetermined negative fixed value −C is −50A.

Along with this, the control device 16 increases the field voltage V _f of the synchronous generator 3 so as to charge the power storage device 4. At this time, as shown in the graph (6d), the generator current I _{gen_dc} becomes larger than the load current I _load , and the difference becomes the current (graph (6c)) for charging the power storage device 4. As a result, as shown in the graph (6b), the charge rate SOC of the power storage device 4 starts to increase. In this simulation, the return reference value is set to 50%. Therefore, even if the charge rate SOC of the power storage device 4 becomes equal to or higher than the lower limit value (30%) of the reference range A, the charge rate SOC continues to increase.

As described above, according to the graph of FIG. 6, when the charge rate SOC of the power storage device 4 deviates from the reference range A by this simulation, the first current I _bat that charges (or discharges) the power storage device 4 It is shown that the field voltage V _f of the synchronous generator 3 is adjusted so that the current flows.

FIG. 7 shows the simulation shown in FIG. 5 when the convergence time is lengthened by reducing the first gain K _p1 of the field voltage target value generation unit 19 (first target value generation unit 20) (T _c1 to T). It is a graph which shows the time change of various current and voltage values of _c2 (when <T _c1 ) is set). In FIG. 7, the graph (7a) is a graph of the DC voltage in the DC wiring 8. Graph (7b) is a graph of the first current _{I bat} and the current target value _{I BAT0.} The graph (7c) is a graph of the generator current I _{gen_dc} and the generator current target value I _{gen 0} . The graph (7d) is a graph of the field voltage V _f . The graph (7e) is a graph _{showing the} load current flowing through the power load 7 together with the generator current I _{gen_dc} and the first current I _bat .

In the simulation shown in FIG. 7, as shown in the graph (7d), the synchronous generator 3 (motor 2) is started at the start of the simulation, and the load current is stepped from 0 to 150 A 2 seconds after the start (stepped). (To) Simulates the case of increase.

In the simulation shown in FIG. 7, similarly to the simulation shown in FIG. 5, the power storage device 4 having a better response than the synchronous generator 3 responds to the load fluctuation due to the load fluctuation 2 seconds after the start, and then the synchronous power generation. Due to the change in the field voltage V _f of the machine 3, the electric power after the load change is supplied by the synchronous generator 3.

However, in this simulation, since the convergence time T _c2 is set longer than the convergence time T _c1 in the simulation of FIG. 5, the time until the rising first current I _bat returns to 0 again is the simulation shown in FIG. It is about 2 seconds longer than that. As described above, according to the graph of FIG. 7, it is shown that the load fluctuation of the synchronous generator 3 and thus the prime mover 2 is made gentler by this simulation as compared with the simulation shown in FIG.

[Other embodiments]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various improvements, changes, and modifications can be made without departing from the spirit of the present invention.

For example, in the above embodiment, the mode of generating the field voltage target value V _f0 by using the generator current I _{gen_dc} as one of the control parameters has been described, but the present invention is not limited to this. For example, the field voltage target value generation unit 19 may output the first current deviation ΔI _bat output from the current deviation calculation unit 18 as it is as the field voltage target value V _f0 , or the first current deviation ΔI _{bat. May} be output as the field voltage target value V _f0 by multiplying by a predetermined coefficient. Further, the field voltage target value generation unit 19 generates a field voltage target value V _f0 by applying a predetermined filter process or the like to the first current deviation ΔI _bat output from the current deviation calculation unit 18. May be good.

Further, the signal output by the control device 16 to the synchronous generator 3 (excitation unit 3a) is a PWM provided in the excitation unit 3a to generate the field voltage V _f instead of the field voltage target value V _f0. It may be a signal that directly indicates the flow rate (duty ratio) of the power supply.

Further, in the above embodiment, when the voltage or charge rate of the power storage device 4 exceeds the upper limit value of the predetermined reference range A, the control device 16 discharges from the power storage device 4 as the first current I _bat. An embodiment in which the field voltage V _f of the synchronous generator 3 is operated so that a current flows is illustrated, but instead, when the voltage or charge rate of the power storage device 4 exceeds the upper limit of the reference range A, , The synchronous generator 3 may be stopped.

For example, the control device 16 stops the synchronous generator 3 by stopping the prime mover 2. As a result, the power storage device 4 bears all the load increase in the power load 7, so that power is supplied from the power storage device 4 to the power load 7. As a result, the voltage or charge rate of the power storage device 4 can be reduced, and the voltage or charge rate of the power storage device 4 can be returned to within the reference range A. Further, the fuel consumption can be reduced by stopping the prime mover 2 that drives the synchronous generator 3.

Further, the control device 16 controls the synchronous generator 3 so that when the voltage or charge rate of the power storage device 4 exceeds the upper limit value of the reference range A, the current discharged from the power storage device 4 flows as the first current I _bat. The field voltage V _{f of the above} may be operated, and the synchronous generator 3 may be stopped when the allowable value larger than the upper limit value thereof is exceeded. That is, when the voltage or charge rate of the power storage device 4 is larger than the upper limit value of the reference range A and is equal to or less than the allowable value, the same control as in the above embodiment is performed, and when the allowable value is exceeded, the synchronous generator 3 is operated. You may stop it.

In addition, in order to stop the synchronous generator 3, it is not always necessary to stop the prime mover 2. For example, a clutch mechanism capable of disengaging the connection between the prime mover 2 and the synchronous generator 3 is provided, and when the upper limit value of the reference range A or the allowable value is exceeded, the clutch mechanism synchronizes with the clutch mechanism. The generator 3 may be disconnected from the prime mover 2 and the synchronous generator 3 may be stopped. Further, the connection between the synchronous generator 3 and the diode rectifier 5 may be disconnected when the synchronous generator 3 is stopped. For example, a circuit breaker may be provided between the synchronous generator 3 and the diode rectifier 5, and the circuit breaker may be opened when the synchronous generator 3 is stopped.

Further, after the synchronous generator 3 is stopped, when the voltage or the charging rate of the power storage device 4 becomes equal to or less than a predetermined restart reference value, the control device 16 restarts the operation of the synchronous generator 3. For example, the restart reference value is set to a value at which the voltage or charge rate of the power storage device 4 is lower than the upper limit value of the reference range A. For example, when the upper limit value of the reference range A in the charge rate of the power storage device 4 is 70%, the restart reference value may be set to 50%. Thereby, when the voltage or the charging rate of the power storage device 4 fluctuates near the upper limit value of the reference range A, it is possible to prevent the synchronous generator 3 from being frequently started and stopped.

Further, in the above embodiment, is set when the lower limit value of the first current I _bat current target value I _BAT0 measurement and reference range A that is set when it exceeds the upper limit of the reference range A the magnitude of the current target value I _BAT0 of the first current I _bat has been the same value (C), is not limited to this, the code is not only different, it may be set to different sizes.

Further, the power supply system 1 described in the above embodiment uses a synchronous generator such as a power supply device for a moving body such as a ship, a railroad, or an aircraft, or a power supply device in a distributed power supply system such as a microgrid. It can be applied to various power supply devices.

The present invention is useful for realizing power load sharing between a synchronous generator and a power storage device with a simple and inexpensive configuration.

1 Power supply system 3 Synchronous generator 4 Power storage device 5 Diode rectifier 6 Inverter 7 Power load 8 DC wiring 16 Control device 17 Current target value generation unit 18 1st current deviation calculation unit 19 Field voltage target value generation unit 20 1st target Value generation unit 21 Second current deviation calculation unit 22 Second target value generation unit

Claims (12)

It is a control device for a synchronous generator in a power supply system.
The power supply system
With the winding field type synchronous generator,
A diode rectifier that rectifies the first AC power output from the synchronous generator into DC power, and
An inverter that converts the DC power into a second AC power and supplies the second AC power to a power load connected to the AC side.
The DC wiring that connects the DC side of the diode rectifier and the DC side of the inverter,
A power storage device that is directly connected to the DC wiring is provided.
The control device is a control device for a synchronous generator, which is configured to control the electric power supplied by the synchronous motor by manipulating the field voltage of the synchronous generator. The synchronous generator according to claim 1, wherein the control device adjusts the load sharing ratio between the synchronous generator and the power storage device with respect to the electric power load by controlling the electric power supplied by the synchronous motor. Control device. It is determined whether or not the voltage or charge rate of the power storage device is within a predetermined reference range.
The field voltage of the synchronous generator is operated so that the first current flowing through the power storage device is constantly set to 0 when the voltage or charge rate of the power storage device is within the reference range. The control device for the synchronous generator according to 1 or 2. When the voltage or charge rate of the power storage device exceeds the upper limit of the reference range, the field voltage of the synchronous generator is operated so that the current discharged from the power storage device flows as the first current. The control device for the synchronous generator according to claim 3. The control device for a synchronous generator according to claim 3, wherein the synchronous generator is stopped when the voltage or charge rate of the power storage device exceeds the upper limit value of the reference range. After the synchronous generator is stopped, the control device operates the synchronous generator when the voltage or charge rate of the power storage device becomes equal to or less than a predetermined start reference value smaller than the upper limit value of the reference range. The control device for the synchronous generator according to claim 5, wherein the second operation is resumed. When the voltage or charge rate of the power storage device falls below the lower limit of the reference range, the field voltage of the synchronous generator is operated so that the current for charging the power storage device flows as the first current. The control device for a synchronous generator according to any one of claims 3 to 6. A current target value generation unit that generates a current target value of the first current from a predetermined power storage device parameter including a voltage or a charge rate of the power storage device.
A first current deviation calculation unit that calculates a first current deviation obtained by subtracting the measured first current from the current target value,
The control device for a synchronous generator according to any one of claims 1 to 7, further comprising a field voltage target value generation unit that generates a field voltage target value of the synchronous generator based on the first current deviation. .. The current target value generator determines whether or not the voltage or charge rate of the power storage device is within a predetermined reference range, and when the voltage or charge rate of the power storage device is within the reference range, The control device for a synchronous generator according to claim 8, wherein the current target value is set to 0. The field voltage target value generator is
It is configured to generate the field voltage target value from the first current deviation based on a transfer function having a predetermined first coefficient.
The first coefficient is set so that the convergence time until the first current deviation converges from a predetermined value to 0 is a convergence time that matches the response performance of the prime mover that drives the synchronous generator. The control device for the synchronous generator according to 8 or 9. The field voltage target value generator is
A first target value generator that generates a generator current target value based on a transfer function having a predetermined first coefficient from the first current deviation,
A second current deviation calculation unit that generates a second current deviation obtained by subtracting the measured generator current from the generator current target value.
The synchronization according to any one of claims 8 to 10, further comprising a second target value generator that generates the field voltage target value based on a transfer function having a predetermined second coefficient from the second current deviation. Generator control device. Winding field type synchronous generator and
A diode rectifier that rectifies the first AC power output from the synchronous generator into DC power, and
An inverter that converts the DC power into a second AC power and supplies the second AC power to a power load connected to the AC side.
The DC wiring that connects the DC side of the diode rectifier and the DC side of the inverter,
A power storage device that is directly connected to the DC wiring,
A control device for controlling the synchronous generator is provided.
The control device is a power supply system configured to control the electric power supplied by the synchronous motor by operating the field voltage of the synchronous generator.