JP5992342B2 - Generator system - Google Patents

Description

  The present invention relates to a generator system capable of operating a generator such that the maximum output can be obtained within the range of the overload capability of the generator.

  In the generator system, the electric power from the generator is supplied to the electric motor to drive the electric motor. As a kind of generator system, it is conceivable to configure a distributed power supply system including an electromagnetic synchronous generator using an electromagnet as a field and a battery group. FIG. 5 is a diagram illustrating a schematic configuration of a distributed power supply system including an electromagnet synchronous generator and a battery group.

  In the configuration example of FIG. 5, the output voltage in the electromagnetic synchronous generator is controlled by a generator operating device (field control device) for analog field excitation control. Further, the voltage generated by the electromagnetic synchronous generator is converted from alternating current to direct current in the rectifier. Moreover, in an inverter, it converts from direct current | flow to alternating current and alternating current power is supplied to an electric motor. The battery can be charged and discharged.

  For example, Patent Document 1 exists as a related art related to the present invention. With the technology according to Patent Document 1, even when an overload is applied, a large load can be handled without stopping the engine.

JP-A-6-178599

  In the distributed power supply system shown in FIG. 5, it is assumed that a steep and large load fluctuation occurs. In the above distributed power supply system, when a large load fluctuation occurs on the system side (motor side), it is necessary to take measures to prevent power generation exceeding the overload capacity of the electromagnetic synchronous generator. As a countermeasure, for example, in the above case, a method of controlling the circuit protection device to be off and disconnecting the electromagnetic synchronous generator from the system is conceivable.

  FIG. 6 is a signal system diagram in the system shown in FIG. In FIG. 6, the state in which the output voltage in the electromagnetic synchronous generator is controlled by the field current signal from the generator operating device (field control device), the circuit by the ON / OFF signal from the generator operating device (field control device) A state in which the protective device is turned off (trip) is shown.

  Moreover, FIG. 7 is a figure which shows time-sequential changes, such as a load fluctuation and a generator electric current. While the output voltage of the generator is controlled to be constant, when the system voltage decreases due to load fluctuations, the generator output current increases accordingly. FIG. 7 also shows how the circuit protection device is controlled to be turned off due to an increase in the generator output current.

  However, in the above case, since it takes several tens of ms or more to turn off the circuit protection device, the overload capacity of the electromagnetic synchronous generator may be exceeded. Further, it is not preferable to frequently turn off the circuit protection device.

  Therefore, conventionally, when a large load fluctuation is assumed, in order to use the electromagnet synchronous generator in the range of the overload amount, an operation in which the output voltage is limited or reduced in advance is performed on the generator side. .

  In other words, in the past, in order to prepare for large load fluctuations, the generator performance has been reduced and cannot be fully utilized.

  Then, it aims at providing the generator system which can drive the said generator in the state which maximized the output of the generator.

In order to achieve the above object, a generator system according to the present invention is provided with a permanent magnet generator using a field by a permanent magnet, the permanent magnet generator, and has a switching function. A switch type rectifier having a rectification function for converting alternating current into direct current, and a generator output voltage is obtained as an output of the switch type rectifier, and a generator side circuit protector and a power circuit line are provided at the output of the switch type rectifier. And an electric motor that converts electrical energy on the power circuit line into mechanical energy, and a control device that controls the switching function of the switch-type rectifier, and the control device supplies the electric motor in response to a change in the power circuit line of the system voltage is the voltage, the system voltage the switched the like generator output voltage is reduced in accordance with reduction in It controls the switching function of the flow device.

A generator system according to the present invention has a permanent magnet generator that uses a field by a permanent magnet, and a rectifying function that is disposed in the permanent magnet generator, has a switching function, and converts alternating current into direct current. A switch rectifier having a generator output voltage as an output of the switch rectifier, connected to the output of the switch rectifier via a generator side circuit protector and a power circuit line, on the power circuit line An electric motor that converts the electrical energy of the switch into mechanical energy, and a control device that controls the switching function of the switch-type rectifier, the control device on the power circuit line being a voltage supplied to the motor depending on the system voltage change of the switching function of the switch rectifier so that the generator output voltage in accordance with reduction of the system voltage drops Control to.

  Therefore, in the generator system which concerns on this invention, the output voltage from a permanent magnet generator can be adjusted according to the change of a system voltage. That is, in the generator system according to the present invention, the generator output voltage can be changed according to the load fluctuation. Therefore, it is not necessary to reduce the performance of the permanent magnet generator in preparation for large load fluctuations, and to maximize the performance of the generator without tripping the circuit protection equipment on the generator side. be able to.

It is a block diagram which shows the structure of the generator system which concerns on embodiment. It is a block diagram which shows the mode of the signal system | strain in the generator system which concerns on embodiment. It is a block diagram for demonstrating the operation | movement of control in the generator system which concerns on embodiment. It is the figure which showed the time _-sequential change of system voltage _VL , generator output voltage VG _-fbk , generator reference voltage VG _-ref, and generator output current _IG-fbk . It is a figure which shows schematic structure of the distributed power supply system comprised from an electromagnet synchronous generator and a battery group. It is a signal system diagram in the distributed power supply system comprised from an electromagnet synchronous generator and a battery group. It is a figure which shows time-sequential changes, such as a load fluctuation and a generator electric current.

  Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.

<Embodiment>
FIG. 1 is a block diagram showing a configuration of a generator system according to the present embodiment. As can be seen from FIG. 1, the generator system according to the present embodiment is a distributed (redundant) distributed power supply system including a battery group and a generator.

  The generator system includes permanent magnet synchronous generators G1 and G2, semiconductor switch type rectifiers THY1 and THY2, control devices DV1 and DV2, generator side circuit protection devices CB1 and CB2, battery side circuit protection devices CB3 and CB4, and battery BT1. , BT2, inverter INV1, and electric motor M.

  As described above, the power supply system is duplicated by the first power supply system G1, THY1, DV1, CB1, CB3, BT1 and the second power supply system G2, THY2, DV2, CB2, CB4, BT2. ing. In normal operation, the first power supply system G1, THY1, DV1, CB1, CB3, BT1 and the second power supply system G2, THY2, DV2, CB2, CB4, BT2 perform the same operation. Power is supplied from the power supply system to the electric motor M. On the other hand, when a failure occurs in any of the power supply systems, power is supplied to the motor M from only the normal power supply system.

  In the configuration example shown in FIG. 1, the power output unit of the permanent magnet synchronous generator G1 is connected to the input side of the semiconductor switch type rectifier THY1, and the output side of the semiconductor switch type rectifier THY1 is the generator side circuit protection device. It is connected to one side of CB1. The other side of the generator-side circuit protection device CB1 is connected to the input side of the inverter INV1 via the node N1 and the node N3 on the system side (bus side). The power output unit of the battery BT1 is connected to one side of the battery side circuit protection device CB3, and the other side of the battery side circuit protection device CB3 is connected to the node N1 and the node N3 on the system side (bus side). To the input side of the inverter INV1.

  Similarly, the power output section of the permanent magnet synchronous generator G2 is connected to the input side of the semiconductor switch type rectifier THY2, and the output side of the semiconductor switch type rectifier THY2 is connected to one side of the generator side circuit protection device CB2. It is connected. The other side of the generator-side circuit protection device CB2 is connected to the input side of the inverter INV1 via the node N2 and the node N3 on the system side (bus side). The power output unit of the battery BT2 is connected to one side of the battery side circuit protection device CB4, and the other side of the battery side circuit protection device CB4 is connected to the node N1 and the node N2 on the system side (bus side). To the input side of the inverter INV1.

  Further, the output unit of the inverter IN1 is connected to the power input side of the electric motor M on the system side (bus side).

  The gate terminal of the semiconductor switch rectifier THY1 is connected to the control device DV1, and the gate terminal of the semiconductor switch rectifier THY2 is connected to the control device DV2.

  The permanent magnet synchronous generators G1 and G2 are synchronous generators using a permanent magnet as a field. The permanent magnet synchronous generators G1 and G2 do not require a generator operating device for field excitation, which is necessary for an electromagnetic synchronous generator.

  Further, the semiconductor switch type rectifiers THY1, THY2 have a rectifying function for converting alternating current into direct current. Further, the semiconductor switch type rectifiers THY1 and THY2 also have a switch function for switching on / off of conduction in accordance with a control signal input from the gate terminal.

  The control devices DV1 and DV2 control the switching function of the semiconductor switch rectifiers THY1 and THY2. Specifically, the control devices DV1 and DV2 generate a control signal for controlling the switch function, and output the control signal to the gate terminals of the semiconductor switch rectifiers THY1 and THY2. The control devices DV1 and DV2 control the switching function of the semiconductor switch type rectifiers THY1 and THY2 according to the change of the system side voltage (which can be grasped as the voltage supplied to the electric motor M).

  As can be seen from the above, in the electromagnetic synchronous generator, the power generation / output voltage is changed by the generator operating device for field excitation control. In this embodiment, the switching function of the semiconductor switch type rectifiers THY1, THY2 Is controlled (by PWM (Pulse Width Modulation) control), the voltage output from the permanent magnet synchronous generators G1 and G2 is changed. Here, compared with the electromagnet synchronous generator by field control, the permanent magnet synchronous generators G1 and G2 of the present embodiment have improved control responsiveness.

The generator side circuit protection circuits CB1 and CB2 are tripped (cut off) when the generator output current I _G-fbk exceeds a predetermined value. The battery-side circuit protection circuit CB3, CB4, the battery output current _{I B} is, when it exceeds a predetermined value, a trip (cut-off). Here, the generator output current I _G-ref is on lines L1 and L2 (the lines L1 and L2 are power lines connecting the semiconductor switch type rectifiers THY1 and THY2 and the generator side circuit protection devices CB1 and CB2). a current flowing through the battery output current _{I B,} the line L3, L4 (line L3, L4 is battery BT1, BT2 and a battery-side circuit protection device CB3, power lines connecting the CB4)) flowing over Current value.

  The batteries BT1 and BT2 are composed of a storage battery group that can be charged and discharged. The inverter INV1 converts direct current into alternating current. The electric motor M is a motor or the like, and converts electric energy supplied to the power supply side (permanent magnet synchronous generators G1 and G2 and batteries BT1 and BT2) into mechanical energy.

  FIG. 2 is a block diagram showing a signal system in the generator system according to the present embodiment.

  Here, in FIG. 2, a thick line is a power circuit line, and a thin line is a signal line. In FIG. 2, the circuit protection devices CB1 to CB4 are not shown for the sake of simplification. As shown in FIG. 2, in the control devices DV1 and DV2, various signals are input and control signals are output.

Specifically, the system voltage _VL is input to the control devices DV1 and DV2. Here, system voltage V _L is a voltage value on the bus side, for example, on line L5 in FIG. 1 (line L5 is a power line on the system side (bus side) and is a power line connected to inverter INV1). Is the voltage value at.

Moreover, the generator output voltage V _G-fbk and the generator output current I _G-fbk are input to the control devices DV1 and DV2. Here, the generator output voltage V _G-fbk and the generator output current I _G-fbk are the voltage value on the output side of the semiconductor switch type rectifiers THY1 and THY2, and the current value on the output side, for example, the line in FIG. The voltage value and the current value on L1 and L2.

Further, the battery voltage V _B and the battery current I _B are input to the control devices DV1 and DV2. Here, battery voltage V _B and battery current I _B are voltage values and current values on the output side of batteries BT1 and BT2, for example, voltage values and current values on lines L3 and L4 in FIG.

  Further, the control devices DV1 and DV2 perform calculations using the input signal and generate a control signal (PWM signal). The control signal is output from the control devices DV1 and DV2 to the gate terminals of the semiconductor switch rectifiers THY1 and THY2.

  Next, operation | movement of the generator system which concerns on this Embodiment is demonstrated using FIG. 3 and FIG.

Here, FIG. 3 is a block diagram showing a state of control in the generator system according to the present embodiment. FIG. 4 is a diagram illustrating time-series changes of the system voltage V _L , the generator output voltage V _G-fbk , the generator reference voltage V _G-ref and the generator output current I _G-fbk .

  As described above, the generator system according to the present embodiment is duplicated (redundant), and in normal operation, the first power supply system G1, THY1, DV1, CB1, CB3, BT1, The same operation is performed with the second power supply system G2, THY2, DV2, CB2, CB4, and BT2 (if a failure occurs in any of the power supply systems, power supply is performed only with the normal power supply system. ).

  Therefore, in order to simplify the description, the operation will be described below focusing on only the first power supply system G1, THY1, DV1, CB1, CB3, and BT1. As described above, the same operation is applied to the second power supply system G2, THY2, DV2, CB2, CB4, and BT2.

In FIG. 3, a threshold change rate is set in advance in the overcurrent detection block B10, and the change rate of the current output from the semiconductor switch type rectifier THY1 (that is, the change rate of the generator output current I _G-fbk ). Is determined to be equal to or greater than the threshold change rate. The voltage detection block B20 detects the voltage output from the permanent magnet synchronous generator G1 (that is, the generator output voltage V _G-fbk ). Further, the current value detection block B30 detects the current output from the permanent magnet synchronous generator G1 (that is, the generator output current I _G-fbk ).

  In FIG. 3, an overcurrent detection block B10, a generator output control block B40, a generator reference voltage correction block (hereinafter referred to as a correction block) B50 and a generator voltage control block B60 due to the generator output current limitation are: It is a functional block in the control device DV1.

Here, the generator reference output KW _G-ref is preset in the control device DV1. The generator reference output KW _G-ref is the maximum output of the permanent magnet synchronous generator G1. The generator reference output KW _G-ref is a generator reference voltage V _G-ref × generator reference current I _G-ref and is a fixed value (the generator reference voltage V _G-ref and the generator reference current I _G-ref is a variation value).

Referring to FIG. 4, system voltage _VL is steady from 0 to time t1, and generator reference voltage V _G-ref and generator output voltage V _{G- are} controlled by feedback control shown in FIG. _fbk is constant at the same value. As shown in FIG. 4, the generator output current I _G-fbk is also constant during the period from 0 to time t1.

Now, at time t1, it is assumed that the system voltage _VL starts to decrease due to load fluctuation. Here, even if the system voltage _VL starts to decrease, at that time, the generator output voltage V _G-fbk does not change immediately by the feedback control shown in FIG. Therefore, as shown in FIG. 4, at time t _<b> 1, the generator output current I _G-fbk starts to increase in accordance with the decrease in the system voltage V _L.

Further, at time t1, the generator reference voltage V _G-ref also starts to change (begin to decrease) by the feedback control shown in FIG. The specific feedback control operation is as follows.

In the control device DV1, the difference between the preset generator reference output KW _G-ref and the feedback generator output KW _G-fbk is taken. Here, the feedback generator output KW _G-fbk is the generator output voltage V _G-fbk × the generator output current I _G-fbk , and as shown in FIG. 3, the generator output voltage V _G-fbk is The generator output voltage value detected in the voltage detection block B20 in the line L1, and the generator output current I _G-fbk is the value of the generator output current flowing in the line L1 detected in the current detection block B30. is there.

Next, the result of the difference is sent to the generator output control block B40 in the control device DV1. In the generator output control block B40, calculation such as proportional integral control is performed, and the generator reference voltage V _G-ref corresponding to the difference between the generator reference output KW _G-ref and the feedback generator output KW _G-fbk is obtained. Generate and output. Then, the generator reference voltage V _G-ref is sent to the correction block B50 in the control device DV1.

In the correction block B50, the generator reference voltage V _G-ref is corrected so that the generator output current I _G-fbk rises rapidly and the generator-side circuit protection device CB1 does not trip. That is, in the correction block B50, the generator reference voltage V _G-ref is corrected so as not to exceed a predetermined upper limit of the generator output current.

Specifically, the correction block B50 also acquires the battery voltage V _B , the system voltage _VL, and the generator output current I _G-fbk on the line L3, and uses these values to generate the generator reference voltage V _G−. An operation for correcting _ref is performed. Result of the computation, the correction block B50 is 'generates a _G-ref, the generator correction reference voltage V' generator corrected reference voltage V and outputs a _G-ref.

Next, in the control device DV1, a difference between the generator correction reference voltage V ′ _G-ref and the generator output voltage V _G-fbk is obtained. The result of the difference is sent to the generator voltage control block B60 in the control device DV1.

In the generator voltage control block B60, calculation such as proportional integral control is performed, and a control signal (PWM signal) corresponding to the difference between the generator correction reference voltage V ′ _G-ref and the generator output voltage V _G-fbk is generated. Generate and output. Then, the control signal is sent to the gate terminal of the semiconductor switch type rectifier THY1.

In the semiconductor switch type rectifier THY1, switching is performed based on the control signal, and the generator output voltage V _G-fbk from the permanent magnet synchronous generator G1 is adjusted.

With the feedback control of FIG. 3, the generator reference voltage V _G-ref starts to decrease according to the decrease of the system voltage V _L as shown in FIG. 4. Specifically, when the system voltage _VL decreases due to a large load fluctuation of the electric motor M or the like, the electrical machine reference voltage V _G-ref starts to decrease immediately (about several ms from the time t1). And according to the generator reference voltage V _G-ref , the generator output voltage V _G-fbk starts to decrease with a time difference. Then, by the feedback control of FIG. 3, the generator reference voltage V _G-ref and the generator reference voltage V _G-ref become the same value, and then the generator reference voltage V _G according to the decrease in the system voltage V _{L. -Ref} and the generator reference voltage V _G-ref are the same value and decrease (see FIG. 4).

It should be _noted that the generator output current I _G-fbk decreases in accordance with a change in which the generator output voltage V _G-fbk decreases to coincide with the generator reference voltage V _G-ref (see FIG. 4). After the generator reference voltage V _G-ref and the generator reference voltage V _G-ref have the same value, the generator output current I _G-fbk returns to a steady state (see FIG. 4).

  Here, in the feedback control shown in FIG. 3, the correction block B50 is provided from the viewpoint of trip suppression of the generator-side circuit protection device CB1, but the correction block B50 can be omitted.

  Further, the series of feedback control shown in FIG. 3 is always performed not only at time t1 but at all times.

In addition, even when the load fluctuation is too steep by the feedback control shown in FIG. 3, the generator output current I _G-fbk may increase rapidly in response to a rapid decrease in the system voltage V _L. is there. In preparation for this case, the generator system according to the present embodiment includes an overcurrent detection block B10 in the control device DV1, as shown in FIG.

As described above, the overcurrent detection block B10 has a threshold change rate set in advance, and constantly monitors the change rate of the generator output current I _G-fbk . Further, the overcurrent detection block B10 determines whether or not the change rate of the generator output current I _G-fbk is equal to or higher than the threshold change rate.

When the change rate of the generator output current I _G-fbk becomes equal to or higher than the threshold change rate, the control device DV1 (more specifically, the overcurrent detection block B10) performs gate-off with respect to the semiconductor switch rectifier THY1. Is transmitted to turn off the semiconductor switch type rectifier THY1.

As described above, in the generator system according to the present embodiment, the control devices DV1 and DV2 cause the permanent magnet synchronous generators G1 and G2 according to the change in the voltage (system voltage V _L ) supplied to the electric motor M. The switch function of semiconductor switch type rectifiers THY1 and THY2 disposed between the motor M and the motor M is controlled.

Therefore, in the generator system according to the present embodiment, the output voltage (generator output voltage V _G-fbk ) from the permanent magnet synchronous generators G1 and G2 can be adjusted in accordance with the change in the system voltage _VL. it can. Thus, in the generator system according to the present embodiment, the generator output voltage V _G-fbk can be changed according to the load fluctuation. Therefore, in preparation for a large load fluctuation, it is not necessary to reduce the performance of the permanent magnet synchronous generators G1 and G2, and the generator G1, without causing the generator-side circuit protection devices CB1 and CB2 to trip. The performance of G2 can be utilized to the maximum.

  Further, in the generator system according to the present embodiment, permanent magnet synchronous generators G1 and G2 that use a permanent magnet field are adopted as the generator, and field excitation control for the electromagnetic synchronous generator is not used. The generator output voltage is adjusted by controlling the switch function of the semiconductor switch type rectifiers THY1 and THY2 disposed between the permanent magnet synchronous generators G1 and G2 and the motor M.

  Therefore, in the generator system according to the present embodiment, the control responsiveness of the output voltage can be improved as compared with the case where the electromagnetic synchronous generator is employed.

Further, the generator system according to the present embodiment includes a correction block B50 for correcting the generator reference voltage V _G-ref so as not to exceed the upper limit of the generator output current. Therefore, it is possible to suppress the generator output current I _G-fbk from rising sharply and causing the generator-side circuit protection devices CB1 and CB2 to trip.

In the generator system according to the present embodiment, the control devices DV1 and DV2 gate off the semiconductor switch rectifiers THY1 and THY2 when the change rate of the generator output current _IG-fbk is equal to or higher than the threshold change rate. To.

Therefore, even if a steep system load fluctuation occurs such that the output voltage (generator output voltage V _G-fbk ) of the permanent magnet synchronous generators G1 and G2 cannot follow, an overload trip of the generators G1 and G2 Trips of the generator side circuit protection devices CB1 and CB2 can be prevented, and the permanent magnet synchronous generators G1 and G2 can be protected from steep load fluctuations.

  In the above description, the present invention has been described by taking as an example a redundant (redundant) distributed power supply system (FIG. 1) including a battery group and a generator. However, the generator system according to the present invention is not limited to the configuration example of FIG. For example, in the configuration example of FIG. 1, the batteries BT1 and BT2 can be omitted, and a configuration that does not employ duplexing (a configuration that includes only the first power supply system or the second power supply system) can also be used.

G1, G2 Permanent magnet synchronous generator THY1, THY2 Semiconductor switch type rectifier DV1, DV2 Control device CB1, DB2 Generator side circuit protection device CB3, CB4 Battery side circuit protection device BT1, BT2 Battery INV1 Inverter M Electric motor B10 Overcurrent detection block B20 Voltage detection block B30 Current detection block B40 Generator output control block B50 Generator reference voltage correction block due to generator output current limitation (correction block)
B60 Generator voltage control block KW _G-ref generator reference output V _G-ref generator reference voltage V ' _G-ref generator correction reference voltage I _G-ref generator reference current KW _G-fbk feedback generator output V _{G -fbk} generator output voltage I _G-fbk generator output current V _L system voltage V _B cell voltage I _B cell current

Claims (2)

A permanent magnet generator using a permanent magnet field;
The permanent magnet generator has a switching function and a switch type rectifier having a rectification function for converting alternating current into direct current, and a generator output voltage is obtained as an output of the switch type rectifier,
An electric motor connected to the output of the switch-type rectifier via a generator-side circuit protector and a power circuit line, and converting electrical energy on the power circuit line into mechanical energy ;
A control device for controlling the switching function of the switch-type rectifier,
The control device includes:
In accordance with the change of the system voltage of said power circuit line is a voltage supplied to the electric motor, the generator output voltage in accordance with reduction of the system voltage for controlling the switching function of the switch rectifier to decrease ,
A generator system characterized by that. The control device includes:
When the rate of change of the current output from the switch type rectifier is equal to or higher than a preset threshold rate of change, the switch type rectifier is turned off.
The generator system according to claim 1.

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