JP4017933B2 - AC excitation type generator motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an AC excitation type generator-motor apparatus, and it is possible to prevent overheating of an AC excitation generator motor and to protect it in a weak excitation range by performing excitation restriction control particularly in a weak excitation range of an AC excitation type generator motor. It is related with the AC excitation type generator-motor apparatus which can be used.
[0002]
[Prior art]
  FIG. 15 is a configuration diagram of a conventional AC excitation generator-motor apparatus disclosed in, for example, Japanese Patent Laid-Open No. 10-257800. In the case of an AC excitation type generator-motor apparatus, the system configuration is such that the primary voltage or reactive power of the AC excitation type generator motor 1 is controlled by d-axis control, and the active power or rotational speed is controlled by q-axis control. The configuration of the d-axis control portion for controlling the primary voltage is shown with the q-axis control portion and the phase detection portion omitted.
[0003]
  In FIG. 15, reference numeral 1 is an AC excitation type generator motor, and 2 is a step-up transformer for boosting the primary voltage of the AC excitation generator motor 1 to the transmission system voltage. Reference numeral 3 denotes a PT (instrument transformer) which steps down the primary voltage of the AC excitation generator 1 for measurement and generates a voltage signal. A voltage detector 4 detects a primary voltage V based on a voltage signal transmitted from PT3. 5 is a subtractor, 6 is a voltage setter for setting a control target value V0 of the primary voltage, and the subtracter 5 detects a deviation ΔV (= V0−V) between the control target value V0 and the primary voltage V.
[0004]
  A controller 7 has a proportional element, an integral element, and a differential element for adjusting the response and stability of the control system, and transmits a signal S1 based on the deviation ΔV detected by the subtractor 5. . Reference numeral 8 denotes an excitation power converter, which can arbitrarily change the generated frequency, generated voltage, phase, etc., and excites the rotor winding of the AC excitation generator-motor 1 based on the signal S1.
[0005]
  The operation of the AC excitation generator-motor apparatus shown in FIG. 15 is as follows. The primary voltage V of the AC excitation generator motor 1 is detected by the voltage detector 4 via PT3, and the deviation ΔV (= V0−) from the control target value V0 set by the voltage setter 6 by the subtractor 5. V) is required. This deviation ΔV is given to the excitation power converter 8 as a signal S1 which is a d-axis current control signal via a controller 7 having a proportional element, an integral element and a derivative element.
[0006]
  The excitation power converter 8 includes the d-axis current control signal (signal S1), the q-axis current control signal from a q-axis current control signal transmission device (not shown), the slip frequency, and the phase of the primary voltage of the AC excitation generator motor 1. The rotor winding of the AC excitation type generator motor 1 is excited so as to be the secondary current of the AC excitation type generator motor 1 according to the voltage, and the primary voltage of the AC excitation type generator motor 1 is set by the voltage setting device 6 The control target value V0 is maintained.
[0007]
  Thus, in the conventional AC excitation generator-motor apparatus, the AC excitation generator-motor 1 can weaken the AC excitation generator motor 1 so that stable operation can be ensured even in the excitation range, and if the insufficient excitation limit is provided, the operation range is narrowed. And had no protective function.
[0008]
[Problems to be solved by the invention]
  However, the AC excitation generator / motor itself has a permissible operating limit, and the AC excitation generator / motor apparatus also depends on the control state. For example, in the operation state in which excitation is performed at a constant excitation frequency, the same as the conventional DC excitation type synchronous machine. There are stable operating limits. For this reason, there has been a problem that the AC excitation type generator motor is damaged due to the operation deviating from the allowable operation range of the AC excitation type generator motor or the step out is caused by the operation outside the stable operation range.
[0009]
  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain an AC excitation type generator-motor apparatus as described below.
a. By limiting excitation in the weak excitation range, overheating of the AC excitation generator motor can be prevented.
b. Stable operation can be achieved by performing excitation limit control in the weak excitation range.
c. The AC excitation type generator motor can be protected in the weak excitation range.
[0010]
[Means for Solving the Problems]
  In order to achieve the above object, in the AC excitation type generator-motor apparatus according to the present invention, the excitation in the weak excitation range by the excitation apparatus for exciting the AC excitation-type generator motor and the excitation apparatus from the allowable output of the AC excitation-type generator motor. Limit based on defined operating limitsIn addition, when the frequency for exciting the AC excitation generator motor is fixed, the operation limit value is changed to the operation limit value determined from the stable operation limit of the AC excitation generator motor.A weak excitation limiting device is provided.
  By limiting the excitation in the weak excitation range based on the operation limit value determined from the allowable output of the AC excitation generator motor, the reactive power flowing into the AC excitation generator motor will not increase and exceed the operation limit value. It is possible to limit the excitation to be weak.In addition, when the frequency for exciting an AC excitation generator / motor is fixed due to restrictions such as the excitation device, the AC excitation generator / motor has the same stable operation limit as that of a DC excitation generator / motor. By changing to the operation limit value determined from the stable operation limit, it is possible to operate stably and limit weak excitation so as not to exceed the operation limit value.
[0011]
  Further, the weakening excitation limiting device operates with the operation limit value determined from the stable operation limit of the AC excitation type generator motor at a time period determined in accordance with the operation limit value determined from the stable operation limit of the AC excitation type generator motor. It is characterized by being changed to a limit value.
Limit control according to the allowable time can be realized.
[0012]
  Furthermore, the weakening excitation limiterDetermined from allowable output of AC excitation generator motorThe operation limit value is a reactive power obtained from the active power of the AC excitation type generator motor at that time under the condition that the apparent power of the AC excitation type generator motor is constant.
  If the operating limit value is a reactive power obtained from the condition that the apparent power of the AC excitation generator motor is constant, the weak excitation can be limited so that the AC excitation generator motor does not become overcurrent.
[0013]
  And the weak excitation limiterDetermined from allowable output of AC excitation generator motorThe operation limit value is a rated current of an AC excitation type generator motor.
  Similarly, weak excitation can be limited so that the AC excitation generator motor does not become overcurrent.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
  1 and 2 show an embodiment of the present invention. FIG. 1 is a configuration diagram of an AC excitation generator-motor apparatus, and FIG. 2 is an explanatory diagram showing an operation range of the AC excitation generator-motor 1. In the case of an AC excitation type generator-motor, the system configuration is such that the primary voltage or reactive power of the AC excitation type generator motor 1 is controlled by d-axis control, and the active power or rotational speed is controlled by q-axis control. The q-axis control part, the phase detection part, etc. are omitted, and the configuration of the d-axis control part for controlling the primary voltage is shown.
[0015]
  In FIG. 1, 1 is an AC excitation type generator motor, 2 is a step-up transformer for boosting the primary voltage of the AC excitation generator motor 1 to the transmission system voltage. Reference numeral 3 denotes a PT (instrument transformer) which steps down the primary voltage of the AC excitation generator 1 for measurement and generates a voltage signal. A voltage detector 4 detects a primary voltage V based on a voltage signal transmitted from PT3. 5 is a subtractor, 6 is a voltage setter for setting a control target value V0 of the primary voltage, and the subtracter 5 detects a deviation ΔV (= V0−V) between the control target value V0 and the primary voltage V.
[0016]
  A controller 7 has a proportional element, an integral element, and a differential element for adjusting the response and stability of the control system, and transmits a signal S1 based on the deviation ΔV detected by the subtractor 5. . Reference numeral 8 denotes an excitation power converter, which can arbitrarily change the generated frequency, generated voltage, phase, etc., and is based on the signal S1 or the signal S2 from the weakening excitation controller 13 described later. Energize the rotor windings.
[0017]
  Reference numeral 9 denotes a CT (instrument current transformer), which transforms the primary current of the AC excitation generator motor 1 at a predetermined ratio to generate a current signal. A signal detector 10 detects active power P, reactive power Q, and primary current J based on the voltage signal and current signal V from PT3 and CT9. Reference numeral 11 denotes an operation limit setter, which calculates and sets an operation limit value Q0 of reactive power on the weak excitation side. This operation limit value Q0 is a negative value on the weak excitation side.
[0018]
  A subtractor 12 detects a deviation ΔQ (= Q0−Q) between the operation limit value Q0 and the reactive power Q detected by the signal detector 10. Reference numeral 13 denotes a weak excitation controller, which has a proportional element, an integral element, and a derivative element for adjusting the response and stability of the control system, and generates a signal S2 based on the deviation ΔQ. Reference numeral 14 denotes a high value selector, which selects a signal having a larger value out of the signal S1 from the controller 7 and the signal S2 from the weak excitation controller 13 and outputs the selected signal to the excitation power converter 8.
[0019]
  The subtractor 5, the voltage setter 6 and the controller 7 are excitation devices, and the signal detector 10, the operation limit setter 11, the subtractor 12, the weakening excitation controller 13 and the high value selector 14 are weakening in the present invention. Excitation limit control device.
[0020]
  FIG. 2 shows the operating range of the AC excitation type generator motor 1, and the horizontal axis shows the effective power of the AC excitation type generator motor 1, the right (+) side indicates the generator operation, and the left (−) side indicates the motor operation range. The vertical axis represents reactive power, with the upper (+) side indicating a strong excitation side for supplying reactive power to the power system, and the lower (−) side indicating a weak excitation side for supplying reactive power from the power system to the AC excitation generator motor 1. Reference numeral 40 denotes a circle centered on P = 0 and Q = 0, and the radius corresponds to the rated apparent power of the AC excitation generator motor 1, and the circle 40 includes the allowable capacity of the stator winding of the AC excitation generator motor 1. As the rated operating range.
[0021]
  The operation range of the strong excitation side is limited by heating of the rotor winding, which is the secondary side of the AC excitation type generator motor 1, but the present invention relates to a control system related to the operation range of the weak excitation side. The limitation of the operating range on the weak excitation side of the AC excitation type generator motor 1 in the circle 40 will be described. Reference numeral 41 denotes a limit curve, which shows the stable operation limit characteristics when operating with the frequency of the output of the excitation power converter 8 supplying current to the rotor winding of the AC excitation generator motor 1 fixed. It is shown. In other words, in the case of operation in which the output frequency of the excitation power converter 8 is fixed, the phase angle cannot be controlled, so that there is a stable operation limit as in the case of the DC excitation generator motor.
[0022]
  The operation limit value Q0 of the reactive power on the weak excitation side output from the operation limit setter 11 is obtained from an equation representing the circle 40 or the limit curve 41 representing the apparent power according to the active power signal P from the signal detector 10. This is the obtained reactive power value.
[0023]
  Next, the operation will be described. When the d-axis current is controlled so that the primary voltage of the AC excitation generator motor 1 becomes the control target value V0 set by the voltage setting device 6, the state of the power system changes, that is, the voltage V on the system side. If the control target value V0 is lowered to maintain the system voltage, the reactive power is weakened and changes to the excitation side. That is, a deviation ΔV (= V0−V) (which is a negative value) between the control target value V0 and the detection voltage V is output from the subtractor 5, and the controller 7 converts the signal S1 based on this deviation ΔV to the deviation ΔV. In order to control in the decreasing direction, it outputs to the high value selector 14.
[0024]
  The operation limit setter 11 obtains the operation limit value Q0 by substituting the active power P at this time into the mathematical expression representing the circle 40. When the reactive power Q detected by the signal detector 10 becomes weaker than the operating limit value Q0, that is, when the reactive power Q exceeds the operating limit value Q0 (in the weak field side, the absolute value of the reactive power Q). Is larger than the absolute value of the operation limit value Q0), which is to exceed the circle 40 downward in FIG. Accordingly, the deviation ΔQ (= Q0−Q) from the subtractor 12 becomes a positive value, and becomes an output in the direction of increasing excitation, and the signal S2 corresponding to the deviation ΔQ is output from the controller 7.
[0025]
  This signal S2 is given to the high value selector 14 via the weakening excitation controller 13. In the high value selector 14, since the signal S2 from the weak excitation controller 13 which is a signal in the direction of increasing excitation is larger than the signal S1 from the arithmetic unit 7, this signal S2 is selected and the excitation power conversion is performed. Give to vessel 8. While the high value selector 14 selects the signal S2 from the weak excitation controller 13, the excitation power converter 8 is set so that the reactive power Q becomes the operation limit value Q0 output from the operation limit setter 11. Therefore, the operation state of the AC excitation type generator motor 1 is maintained at the operation limit value Q0.
[0026]
  In this state, the state of the system returns to the original state, that is, the voltage on the system side decreases and the excitation side is weaker, and the absolute value of the reactive power Q output from the operation limit setter 11 is greater than the absolute value of the operation limit value Q0. When the signal S2 becomes smaller, and the signal S2 becomes a negative value and becomes smaller than the signal S1 from the controller 7, the high value selector 14 selects the signal S1 which is the larger value of the two, and the excitation power The voltage is applied to the converter 8 to return to normal voltage control.
[0027]
  As described above, the AC excitation type generator motor 1 can be operated without the absolute value of the reactive power Q exceeding the absolute value of the operation limit value Q0 output from the operation limit setter 11. Overheating and unstable operation on the stator side of the electric motor 1 can be prevented.
[0028]
  In FIG. 1, one of the signal S 1 output from the controller 7 and the signal S 2 output from the weakening excitation controller 13 is selected by the high value selector 14, but is output from the subtractor 5. One of the deviation ΔV and the deviation ΔQ output from the subtractor 12 may be selected and output to the excitation power converter 8 via the controller 7.
[0029]
  The operation limit value Q0 output by the operation limit setter 11 has been described for obtaining the reactive power value from the mathematical expression representing the circle 40 in accordance with the active power P of the AC excitation type generator motor 1. It may be obtained from mathematical expressions approximated by, for example, or may be obtained by preparing a data table, selecting approximate points and interpolating them.
[0030]
  Further, the above description has been given of what is limitedly controlled so as to have the characteristic represented by the circle 40 indicating the rated operating range. However, the characteristic with allowance for this characteristic, or the overload of the AC excitation generator motor 1 You may restrict | limit so that it may become the characteristic which considered tolerance.
[0031]
Embodiment 2. FIG.
  FIG. 3 is a configuration diagram of an AC excitation generator-motor apparatus showing another embodiment of the present invention. In the embodiment shown in FIG. 1, the high value selector 14 is used. Instead, an adder 51 is provided as shown in FIG. Since other configurations are the same as those of the first embodiment shown in FIG. 1, the same reference numerals are given to the corresponding components and the description thereof is omitted. Note that, in the drawings showing the following embodiments, the same reference numerals are the same or similar to each other, and therefore, redundant description is omitted in the following embodiments.
[0032]
  The adder 51 adds the signal S <b> 1 from the controller 7 and the signal S <b> 2 from the weak excitation controller 13, and supplies the result to the excitation power converter 8. That is, normally, when the signal S1 from the controller 7 becomes a negative value and the excitation is reduced, weak excitation is performed. Accordingly, the signal S2 from the weak excitation controller 13 (a positive value when the limit is reached) is added by the adder 51, and is supplied to the excitation power converter 8 to limit the reduction of the excitation amount. To do.
[0033]
  Instead of adding the signal S2 from the weak excitation controller 13, the control target value V0 of the voltage setter 6 may be changed. In short, AC excitation is performed via the excitation power converter 8 so that the absolute value of the reactive power Q of the AC excitation generator motor 1 does not exceed the absolute value of the operation limit value Q0 output from the operation limit setter 11. What is necessary is just to control the exciting current of the rotor winding of the generator motor 1.
[0034]
Embodiment 3 FIG.
  FIG. 4 is a configuration diagram of an AC excitation generator-motor apparatus showing still another embodiment of the present invention. In this embodiment, the circle 40 indicating the rated operating range has a characteristic in which the temperature rise of the stator of the AC excitation generator motor 1 is constant, that is, a characteristic in which the primary current is constant. On the condition that the primary current of the AC excitation type generator motor 1 is not limited to the limit current value determined by the circle 40, the same effect is obtained.
[0035]
  That is, an allowable primary current value J0 is set by the operation limit setting device 61, and a subtractor 62 calculates a deviation ΔJ (= J0−J) between the allowable primary current current J0 and the current J detected by the signal detector 10. And input to the weakening excitation controller 63. The weakening excitation controller 63 generates a signal S3 based on the deviation ΔJ and supplies the signal S3 to the high value selector 14 via the switch 17.
[0036]
  The weak excitation detector 64 detects that the AC excitation type generator motor 1 is operated on the weak excitation side based on the fact that the reactive power Q is in the leading phase during the power generation operation and in the slow phase during the pumping operation. That is, a switching command is issued to the switch 17 only when the operation state is on the weak excitation side. Upon receiving this switching command, the switching unit 17 switches the signal S3 from the excitation controller 63 so as to be input to the high value selector 14, and validates the limiting function on the weak excitation side. Thereby, the limiting control on the weak excitation side is realized. The signal detector 10, the operation limit setter 61, the subtractor 62, the weak excitation controller 63, the weak excitation detector 64, the switch 17 and the high value selector 14 are the weak excitation limit control device in the present invention.
[0037]
  Note that the switch 17 is opened when the operation is not on the weak excitation side. Therefore, although not shown, when a low level setting device is provided and the switch 17 is open, the voltage level of the terminal of the high value selector 14 to which the signal S3 is input via the switch 17 is changed from the controller 7. Is set to a value on the minus side that is sufficiently lower than the level of the signal S1 (usually, changes within a certain range of plus or minus), and when the switch 17 is open, the high value selector 14 always starts from the controller 7. The signal S1 is selected. Further, the switching command is issued to the switch 17 only when the weak excitation detector 64 is in the operation state on the weak excitation side when the primary current is limited by the circle 40 of the operation range characteristic. This is because in order to return the operation state exceeding the current value to the limit current value, the excitation may be controlled in the increasing direction.
[0038]
  In addition, although what used the primary current of AC excitation type generator motor 1 was demonstrated, it is what uses the primary current calculated | required by dividing | segmenting the apparent electric power of AC excitation type generator motor 1 or an apparent power by a primary voltage, etc. The same effect can be obtained.
[0039]
Embodiment 4 FIG.
  FIG. 5 is a block diagram of an AC excitation generator-motor apparatus showing still another embodiment of the present invention. In the first embodiment, when the operation state of the AC excitation generator-motor 1 comes outside the circle 40 that is the rated operation range, the weakening excitation restriction is effective immediately. On the other hand, the size of the circle 40 is determined by the primary current of the AC excitation type generator motor 1, that is, the temperature rise of the stator, and this tolerance is specified as a function of time by the Institute of Electrical Engineers of Japan (JEC2130). ing. Therefore, in order to maintain the voltage of the power system or absorb reactive power, it may be required to operate in a state that temporarily exceeds the circle 40 that is the rated operation range and is outside the circle.
[0040]
  The AC excitation generator-motor apparatus shown in FIG. 5 is for satisfying such a requirement, and the operation state of the AC excitation generator-motor 1 has exceeded the operation limit value Q0 set by the operation limit setter 11. That is, that is, the operating state detector 15 that detects that the signal S2 output from the weakening excitation controller 13 exceeds a predetermined value, the time limit circuit 16 that is activated by the signal from the operating state detector 15, and the time limit circuit 16 A switch 17 is provided for receiving the command signal from the weak excitation controller 13 and inputting the signal S2 from the weak excitation controller 13 to the high value selector 14.
[0041]
  Next, the operation will be described. The operation state detector 15 indicates that the operation state of the AC excitation generator motor 1 is set by the operation limit setter 11 and exceeds the operation limit value Q0, that is, the value of ΔQ (= Q0-Q) becomes positive. When this is detected, the time limit circuit 16 is activated. The time limit circuit 16 receives the activation signal, counts the number of pulses emitted at a constant time interval, and gives a switch signal to the switch 17 when the operation state exceeding the operation limit value Q0 continues for a predetermined time. The switch 17 receives this switch signal and gives the signal S2 from the weak excitation controller 13 to the high value selector 14. As a result, the limit of weak excitation is started and the reactive power is pulled back to the operation limit value Q0 set by the operation limit setter 11.
[0042]
  As a result, it is possible to temporarily allow the operation beyond the rated operation range and prevent the stator temperature of the AC excitation generator motor 1 from exceeding the allowable increase limit. The operation state detector 15 operates with the operation limit value Q0 and has a hysteresis characteristic with a difference between the operation value and the return value so as to return with another value smaller than the operation limit value Q0. It is good.
[0043]
  In addition, the time limit circuit 16 may have a fixed time characteristic such that it operates after a predetermined time by counting the number of pulses emitted at a constant time interval by the start signal from the operation state detector 15 as described above. Alternatively, an integration circuit or the like may be used so as to have an inverse time characteristic that operates after a lapse of time that is inversely proportional to the excess from the operation limit value Q0.
[0044]
Embodiment 5 FIG.
  FIG. 6 is a configuration diagram of an AC excitation generator-motor apparatus showing still another embodiment of the present invention. The AC excitation type generator motor 1 is normally operated by the excitation power converter 8 at a frequency corresponding to the change of the slip frequency (the difference between the system frequency and the actual rotational speed of the AC excitation type generator motor 1). The rated operating range at this time is inside the circle 40 in FIG. However, in general, the slip frequency that can be operated by the excitation power converter 8 is determined in consideration of the size, price, and system operation requirements of the excitation power converter 8, and the limit Excitation at a slip frequency exceeding the value is not possible.
[0045]
  For this reason, when the slip frequency reaches the limit value, a method of fixing the excitation frequency to the limit value may be used so that the operation state at the slip frequency exceeding the limit value is not reached. In this way, when the excitation frequency is fixed, the AC excitation type generator motor 1 is in the same operating state as a DC excitation type generator motor that cannot be accelerated or decelerated by excitation control, and is the same as the DC excitation type generator motor in FIG. There is a stable operating limit shown in curve 41. This embodiment is for causing the AC excitation type generator motor to operate in a stable and safe range in response to such a change in the operating state.
[0046]
  In FIG. 6, reference numeral 71 denotes an operation limit setter at a fixed frequency, and based on the characteristic represented by the limit curve 41 in FIG. 2, the operation limit value of the active power P of the AC excitation generator motor 1 and the reactive power at that time Find Q0. Reference numeral 72 denotes setting value switching means, which detects that the frequency of the output current of the excitation power converter 8 has reached the upper limit or the lower limit and the excitation frequency of the AC excitation generator motor 1 has been fixed, The operation limit set value set in this way and the frequency fixed operation limit set value set by the frequency fixed operation limit setter 71 are switched to be given to the subtractor 12 as the operation limit value Q0. The subsequent operation is the same as that of the embodiment shown in FIG.
[0047]
  By doing so, even when the slip frequency is fixed at the upper limit or the lower limit that can be supported by the excitation power converter 8, or when the slip frequency is fixed at a certain frequency within the upper and lower limits, the excitation frequency in the weak excitation range can be reduced. By performing the limit control, stable operation can be performed.
[0048]
Embodiment 6 FIG.
  FIG. 7 is a configuration diagram of an AC excitation generator-motor apparatus showing still another embodiment of the present invention. In the embodiment shown in FIG. 6, the signal S <b> 2 of the weak excitation controller 13 is directly output to the excitation power converter 8. In this embodiment, an operation state detector 15, a time limit circuit 16, a second time limit circuit 75, and a time signal switch means 76 are provided in the configuration shown in FIG. The second time circuit 75 operates in a time period determined in accordance with a limit curve 41 which is a stable operation limit characteristic when the AC excitation generator motor 1 is operated with the slip frequency fixed. ing.
[0049]
  The operation state detector 15 indicates that the operation state of the AC excitation generator motor 1 is set by the operation limit setter 11 and exceeds the operation limit value Q0, that is, the value of ΔQ (= Q0-Q) becomes positive. When this is detected, the time limit circuit 16 and the second time limit circuit 75 are activated. The time limit signal switching means 76 gives the output signal of the time limit circuit 16 to the switch 17 when the output frequency of the excitation power converter 8 is not fixed, and the second time limit circuit 75 when the output frequency is fixed. An output signal is supplied to the switch 17.
[0050]
  When the AC excitation generator motor 1 is excited at a variable frequency, the set value switching means 72 gives the operation limit value set by the operation limit setter 11 to the subtractor 12 as the operation limit value Q0, and the AC When the excitation frequency of the excitation generator motor 1 is fixed, the operation limit value set by the operation limit setting unit 71 when the frequency is fixed is given to the subtractor 12 as the operation limit value Q0.
[0051]
  When the operation state exceeding the operation limit value Q0 continues for the time set in the time limit circuit 16, the time limit circuit 16 operates to generate an output signal, and the time set for the second time limit circuit 75 continues. In such a case, the second timing circuit 75 operates to generate an output signal. The switch 17 is operated by any one of the output signals, the signal S2 from the weak excitation controller 13 is given to the high value selector 14, the weak excitation limit is started, and the reactive power is pulled down to the operation limit set value Q0. return.
[0052]
  As described above, the operation limit value Q0 is switched according to whether the slip frequency is in a variable state or the slip frequency is in a fixed state, and the time limit set value is switched by the time limit signal switching means 76, thereby allowing an allowable time. Responsive control can be realized.
[0053]
  When the stability limit is exceeded in the constant frequency excitation operation state (when the reactive power is on the minus side of the limit curve 41) and there is no time margin, the set time limit of the second time limit circuit 75 is set to 0. Alternatively, the second time circuit 75 may be omitted, and the signal of the operation state detector 15 may be directly input to the time signal switching means 76.
[0054]
Embodiment 7 FIG.
  FIG. 8 is a block diagram of an AC excitation generator-motor apparatus showing still another embodiment of the present invention. In FIG. 8, reference numeral 24 denotes a signal logic circuit. The signal S 2 of the weak excitation controller 13 is an output in the weak excitation limit direction, and the primary voltage V input from the voltage detector 4 is within the limit value of the AC excitation generator motor 1. If so, a signal is supplied to the high value selector 14 via the switch 17, but when the primary voltage exceeds the limit value, the signal S 2 is disconnected by the switch 17 and supplied to the high value selector 14. It is something to avoid. The signal logic circuit 24 is an operation prohibiting means for prohibiting the operation of the weak excitation limiting device according to the present invention.
[0055]
  When the AC excitation type generator motor 1 is operated while being connected to a capacitive power system, the AC excitation type generator motor 1 is operated in a weaker excitation direction. Even if the weakening excitation limiting control function operates in such a power system state and the excitation of the AC excitation generator motor 1 is increased, the primary voltage increases, but the reactive power may not be changed to the stronger excitation side. If this state continues, the primary voltage of the AC excitation type generator-motor 1 rises to a limit value or more, and the AC excitation type generator-motor may be damaged due to dielectric breakdown or the like. Therefore, when the primary voltage exceeds the limit value, the switch 17 disconnects the signal S2 so that it is not supplied to the high value selector 14.
[0056]
  According to this embodiment, it is possible to prevent the AC excitation type generator motor 1 from being damaged by the overvoltage of the primary voltage by the weakening excitation limiting control.
[0057]
Embodiment 8 FIG.
  FIG. 9 is a block diagram of an AC excitation generator-motor apparatus showing still another embodiment of the present invention. In FIG. 9, reference numeral 25 denotes a limit voltage setter for setting the upper limit voltage Vu of the AC excitation type generator motor 1, and 26 denotes a subtractor. The primary voltage V detected by the voltage detector 4 and the limit voltage setter 25 are A deviation ΔVu (= Vu−V) from the set upper limit voltage Vu is obtained.
[0058]
  Reference numeral 27 denotes a controller of a voltage suppression control circuit composed of elements such as proportionality, integration, and differentiation, and generates a signal S4 in a direction to decrease the deviation ΔVu based on the deviation ΔVu input from the subtractor 26. Reference numeral 28 denotes a low value selector, which compares the signal S2 of the weak excitation controller 13 with the signal S4 of the controller 27, and selects a low value signal (a signal in a direction in which excitation is further reduced). The limit voltage setter 25, the subtractor 26 and the controller 27 are voltage limiting means in the present invention.
[0059]
  According to this embodiment, when the excitation is increased by the signal S2 from the weak excitation controller 13 and the primary voltage of the AC excitation generator 1 exceeds the upper limit voltage Vu set by the limit voltage setter 25, the low The value selector 28 selects the signal S4 in the direction to reduce the excitation emitted from the controller 27. When the signal S2 or S4 selected by the low value selector 28 is input, the high value selector 14 cuts off the signal S1 from the controller 7, and selects the signal S1 or S4 which is the signal at the higher value. The excitation power converter 8 is supplied.
[0060]
  As a result, the primary voltage of the AC excitation type generator-motor 1 is suppressed below the set value Vu of the limit voltage setting unit 25, and the AC excitation type generator-motor 1 is damaged by overvoltage without using the switch 17 in FIG. Can be prevented.
[0061]
  Although FIG. 9 shows an example in which the low value selector 28 is applied, a subtracting circuit for subtracting the signal S4 of the controller 27 from the signal S2 of the controller 13 is provided, or the signal S2 of the controller 13 is A similar effect can be obtained even by providing an output limiting circuit that limits the upper limit value by the signal S4 from the controller 27.
[0062]
  Further, even when the operation is stopped when the primary voltage becomes equal to or greater than the limit value of the AC excitation generator / motor 1, it is possible to prevent the AC excitation generator / motor 1 from being damaged by overvoltage.
[0063]
Embodiment 9 FIG.
  FIG. 10 is a configuration diagram of an AC excitation generator-motor apparatus showing still another embodiment of the present invention. 10, reference numeral 29 denotes a second limit value setter, which corresponds to the active power P at that time based on the circle 40 in FIG. 2, the limit curve 41 or a characteristic corresponding thereto, in the embodiment of FIG. A second operation limit value Q2, which is a predetermined limit value larger than the operation limit value Q0 set by the operation limit setter 11 or the operation limit setter 71 when the frequency is fixed, is set.
[0064]
  Reference numeral 30 denotes a subtractor for obtaining a deviation ΔQ2 (= Q2−Q) between the second operation limit value Q2 set by the second operation limit setter 29 and the reactive power Q. Reference numeral 31 denotes a second limit detector that issues a stop signal when the deviation ΔQ2 from the subtracter 30 becomes positive. Reference numeral 39 denotes an operation stop device that receives the stop signal from the second limit detector 31 and stops the operation of the AC excitation generator motor 1. The second operation limit set value 29, the subtractor 30, the second limit detector 31, and the operation stop device 39 are the operation stop command means in the present invention.
[0065]
  The second limit detector 30 detects that the operation state of the AC excitation generator motor 1 has exceeded the second operation limit value Q2 set by the second operation limit setter 29, and generates a stop signal. Then, the AC excitation generator motor 1 is stopped by the operation stop device 39, whereby damage such as burning of the AC excitation generator motor 1 due to weak excitation exceeding the limit can be prevented.
[0066]
Embodiment 10 FIG.
  FIG. 11 is a configuration diagram of an AC excitation generator-motor apparatus showing still another embodiment of the present invention. In FIG. 11, a time limit circuit 33 is added to the AC excitation generator-motor apparatus shown in FIG. A stop signal of the second limit detector 31 is supplied to the operation stop device 39 via the time limit circuit 33.
[0067]
  The second limit detector 31 detects that the operation state of the AC excitation generator-motor 1 has exceeded the second operation limit value Q2 set by the second limit setter 29, and issues a stop signal. When the state in which the stop signal is transmitted continues for a predetermined time, the timing circuit 33 transmits an operation stop command for the AC excitation generator motor 1 to the operation stop device 39 to stop the AC excitation generator motor 1. The second operation limit set value 29, the subtractor 30, the second limit detector 31, the time limit circuit 33, and the operation stop device 39 are the operation stop command means in the present invention.
[0068]
  As a result, the operation can be continued within an allowable time even if the AC excitation type generator motor 1 exceeds a predetermined limit value in weak excitation. Therefore, an operation utilizing the overload capability of the AC excitation generator-motor 1 is possible.
  The time limit circuit 33 may have a fixed time limit characteristic or an anti-time limit characteristic corresponding to a degree exceeding the predetermined limit value (the magnitude of ΔQ2). The operation | movement which utilized the tolerance | capacitance which the electric motor 1 has more effectively is attained.
[0069]
Embodiment 11 FIG.
  FIG. 12 is a configuration diagram of an AC excitation generator-motor apparatus showing still another embodiment of the present invention. The AC excitation generator-motor apparatus in FIG. 12 performs control for limiting weak excitation, which is the embodiment shown in FIG. 1, and exceeds the second operation limit value Q2, which is the embodiment shown in FIG. In this case, the AC excitation generator motor 1 is stopped and the AC excitation generator motor 1 is protected.
[0070]
  The second operation limit value Q2 of the second limit setter 29 is weaker than the operation limit value Q0 set by the operation limit setter 11, and is set to the excitation side, that is, the second value from the absolute value of the operation limit value Q0. By setting the absolute value of the operating limit value Q2 to be large, it is possible to prevent the AC excitation type generator motor 1 from being burned out by continuing the weak excitation state despite the weak excitation limitation control being performed. Is possible.
[0071]
Embodiment 12 FIG.
  FIG. 13 is a block diagram of an AC excitation generator-motor apparatus showing still another embodiment of the present invention. In FIG. 13, a time limit circuit 33 is provided between the second limit detector 31 and the operation stop device 39. The time limit circuit 33 has an inverse time limit characteristic according to a certain time limit or the extent to which the reactive power Q exceeds the second operation limit value Q2.
[0072]
  By configuring in this way, even when the state where the second operation limit value Q2 is exceeded in the weakening excitation in the operation state by the limit control in the weakening excitation range, the weak excitation side of the AC excitation type generator motor 1 has It is possible to make use of the allowable driving capacity and to operate within an allowable time limit.
[0073]
Embodiment 13 FIG.
  FIG. 14 is a configuration diagram of an AC excitation generator-motor apparatus showing still another embodiment of the present invention. 14 is a combination of the one shown in FIG. 5 and the one shown in FIG. A time limit circuit 33 is provided between the second limit detector 31 and the operation stop device 39. The time limit circuit 33 has an inverse time limit characteristic according to a certain time limit or the extent to which the reactive power Q exceeds the second operation limit value Q2.
[0074]
  With this configuration, the operation state detector 15 detects that the operation state of the AC excitation generator motor 1 is set by the operation limit setter 11 and exceeds the operation limit value Q0, that is, ΔQ (= Q0−Q When the value of) is detected as positive, the time limit circuit 16 is activated. When the operation state exceeding the operation limit value Q0 continues for a predetermined time, a switching signal is given from the time limit circuit 16 to the switch 17 and a signal S2 from the weak excitation controller 13 is given to the high value selector 14 to limit the weak excitation. The reactive power is pulled back to the set value Q0 of the operation limit setter 11.
[0075]
  Further, when the operation state of the AC excitation generator motor 1 exceeds the second operation limit value Q2 set by the second operation limit setter 29, this is detected by the second limit detector 31. Issue a stop signal. When the state in which the stop signal is transmitted continues for a predetermined time, the timing circuit 33 transmits an operation stop command for the AC excitation generator motor 1 to the operation stop device 39 to stop the AC excitation generator motor 1.
[0076]
  As a result, even when the state where the predetermined limit value in the weak excitation is exceeded in the operation state by the restriction control in the weak excitation region, the allowable operation side on the weak excitation side of the AC excitation type generator motor 1 is utilized and allowed. Can be operated within a limited time limit.
[0077]
  In addition, as for the limiting control in the weak excitation range, the voltage and reactive power control by the d-axis control has been shown. However, in the case of the AC excitation type generator motor, the active power can be adjusted by the q-axis excitation control and effective. Even if the control of power or both reactive power and active power is controlled, it is possible to realize the limit control on the weak side.
[0078]
  Further, the active power can be controlled by adjusting the opening degree of the guide vane in addition to the excitation control, and can also be realized by controlling both the excitation control system and the guide vane control system.
[0079]
【The invention's effect】
  Since the present invention is configured as described above, the following effects can be obtained.
[0080]
  The AC excitation generator / motor apparatus according to the present invention limits the excitation in the weak excitation range by the excitation device for exciting the AC excitation generator motor based on the operating limit value determined from the allowable output of the AC excitation generator motor. DoIn addition, when the frequency for exciting the AC excitation generator motor is fixed, the operation limit value is changed to the operation limit value determined from the stable operation limit of the AC excitation generator motor.Because it has a weak excitation limiter,
  By limiting the excitation in the weak excitation range based on the operation limit value determined from the allowable output of the AC excitation generator motor, the reactive power flowing into the AC excitation generator motor will not increase and exceed the operation limit value. Therefore, it is possible to prevent overheating of the AC excitation type generator motor.In addition, when the frequency for exciting an AC excitation generator / motor is fixed due to restrictions such as the excitation device, the AC excitation generator / motor has the same stable operation limit as that of a DC excitation generator / motor. By changing to the operation limit value determined from the stable operation limit, it is possible to stably operate and limit weak excitation so as not to exceed the operation limit value, thereby preventing overheating of the AC excitation type generator motor.
[0081]
  Further, the weakening excitation limiting device operates with the operation limit value determined from the stable operation limit of the AC excitation type generator motor at a time period determined in accordance with the operation limit value determined from the stable operation limit of the AC excitation type generator motor. Since it is characterized by changing to the limit value,
Limit control according to the allowable time can be realized.
[0082]
  Furthermore, the weakening excitation limiterDetermined from allowable output of AC excitation generator motorSince the operation limit value is characterized by reactive power obtained from the active power of the AC excitation type generator motor at that time under the condition that the apparent power of the AC excitation type generator motor is constant,
  If the operating limit value is a reactive power obtained from the condition that the apparent power of the AC excitation type generator motor is constant, the AC excitation type generator motor is limited so that the AC excitation type generator motor does not become overcurrent. The generator motor can be prevented from overheating.
[0083]
  And the weak excitation limiterDetermined from allowable output of AC excitation generator motorSince the operating limit value is the rated current of the AC excitation generator motor,
  Similarly, weak excitation can be limited so that the AC excitation generator motor does not become overcurrent.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a configuration of an AC excitation generator-motor apparatus according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing an operation range of an AC excitation generator motor 1;
FIG. 3 is a configuration diagram of an AC excitation generator-motor apparatus showing another embodiment of the present invention.
FIG. 4 is a configuration diagram of an AC excitation generator-motor apparatus showing another embodiment of the present invention.
FIG. 5 is a configuration diagram of an AC excitation generator-motor apparatus showing another embodiment of the present invention.
FIG. 6 is a configuration diagram of an AC excitation generator-motor apparatus showing another embodiment of the present invention.
FIG. 7 is a configuration diagram of an AC excitation generator-motor apparatus showing another embodiment of the present invention.
FIG. 8 is a configuration diagram of an AC excitation generator-motor apparatus showing another embodiment of the present invention.
FIG. 9 is a configuration diagram of an AC excitation generator-motor apparatus showing another embodiment of the present invention.
FIG. 10 is a configuration diagram of an AC excitation generator-motor apparatus showing another embodiment of the present invention.
FIG. 11 is a configuration diagram of an AC excitation generator-motor apparatus showing another embodiment of the present invention.
FIG. 12 is a configuration diagram of an AC excitation generator-motor apparatus showing another embodiment of the present invention.
FIG. 13 is a configuration diagram of an AC excitation generator-motor apparatus showing another embodiment of the present invention.
FIG. 14 is a configuration diagram of an AC excitation generator-motor apparatus showing another embodiment of the present invention.
FIG. 15 is a configuration diagram showing a configuration of a conventional AC excitation generator-motor apparatus.
[Explanation of symbols]
  1 AC excitation type generator motor, 2 step-up transformer, 3 PT, 4 voltage detector,
5 Subtractor, 6 Voltage setter, 7 Controller, 8 Excitation power converter,
9 CT, 10 signal detector, 11 operation limit setter, 12 subtractor,
13 Weaker excitation controller, 14 High value selector, 15 Operating state detector,
16 timed circuit, 17 switcher, 24 signal logic circuit,
25 limit voltage setter, 26 subtractor, 27 controller, 28 low value selector,
29 second operation limit setter, 30 subtractor, 31 second limit detector,
33 time limit circuit, 39 operation stop device, 40 yen, 41 limit curve,
52 adder, 61 operation limit setter, 62 subtractor,
63 Weak excitation controller, 64 Weak excitation detector,
71 Frequency limit operation limit setter, 72 set value switching means,
75 Second time circuit, 76 time signal switching means.

Claims (4)

An excitation device for exciting an AC excitation type generator motor and excitation in a weak excitation range by the excitation device are limited based on an operation limit value determined from an allowable output of the AC excitation type generator motor, and the AC excitation type generator motor is An AC excitation type generator-motor apparatus comprising a weakening excitation limiting device that changes the operation limit value to an operation limit value determined from a stable operation limit of the AC excitation type generator-motor when the excitation frequency is fixed . The weakening excitation limiting device determines the operation limit value from the stable operation limit of the AC excitation type generator-motor at a time period determined corresponding to the operation limit value determined from the stable operation limit of the AC excitation type generator-motor. 2. The AC excitation type generator-motor apparatus according to claim 1, wherein the AC excitation type generator-motor apparatus is changed to an operation limit value . The operation limit value determined from the allowable output of the AC excitation type generator motor of the weak excitation limiter is the AC excitation type generator motor at that time under the condition that the apparent power of the AC excitation type generator motor is constant. The AC excitation type generator-motor apparatus according to claim 1, wherein the reactive power is obtained from the active power of the AC excitation power generator. 3. The AC according to claim 1, wherein an operation limit value determined from an allowable output of the AC excitation type generator-motor of the weak excitation limiter is a rated current of the AC excitation type generator-motor. Excitation type generator motor.

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