JP5490503B2 - Control device and control method for synchronous generator - Google Patents

Description

  The present invention relates to a speed control device and a speed control method for a synchronous generator that do not cause a control delay and a problem caused by the control delay when the synchronous generator is synchronized with a power system.

  In order to synchronously connect a synchronous generator connected to a prime mover to a power system (hereinafter simply referred to as parallel input), the voltage, frequency and phase of the output of the synchronous generator substantially match those of the power system. It is necessary to satisfy the synchronous parallel permission condition. In a power plant where a synchronous generator is installed, an automatic synchronizer is usually installed, and the voltage, frequency, and phase of the power generation output of the synchronous generator are monitored, and are within a preset set value range. Whether or not the synchronous parallel permission condition is satisfied is determined based on whether or not the synchronous parallel permission condition is satisfied. This automatic synchronizer includes an automatic voltage balance adjuster (60), a speed adjuster (15), and a synchronism detector (25). As described above, the control device number in the automatic synchronizer includes the device name and the control device number in parentheses (the same applies hereinafter).

  FIG. 2 is a block diagram showing an outline of frequency control (speed regulation control) in a conventional parallel control system for a synchronous generator power system. In the system shown in this figure, the output side of the synchronous generator 4 connected to the prime mover 2 is connected to the power system 6 via the circuit breaker 8, and the power system 6 is connected to the instrument transformer 10. The automatic voltage balance adjuster (60) 13, the speed adjuster (15) 14, and the automatic synchronizer (25) 15 are connected to the automatic synchronizer 12 having the built-in function.

  In the conventional parallel control system shown in FIG. 2, speed control is performed as shown below. A system frequency signal from the power system 6 through the instrument transformer 10 is input to the speed adjustment device (15) 14 in the automatic synchronizer 12. On the other hand, a measurement signal (not shown) of the rotational speed (frequency) of the prime mover 2 is also input to the speed adjusting device (15) 14 in the automatic synchronizer. The speed adjustment device (15) 14 detects a deviation between the input system frequency signal and the generator rotation signal. When the deviation is within a predetermined settling value range, a closing operation signal is issued from the automatic synchronizer 12 to the circuit breaker 8 by satisfying other synchronous parallel permission conditions (voltage and phase).

  On the other hand, when a deviation is detected outside the predetermined set value range, a rotation speed change command corresponding to the deviation amount is sent from the speed adjustment device (15) 14 to the speed / load setting device (65F / 65P) 16. Sent to. The speed / load setter (65F / 65P) changes the speed set value, and the speed governor 18 issues an operation amount signal to the prime mover control operation unit 20 so as to match the changed speed set value. In response to the input of the operation amount signal, the prime mover control operation unit 20 operates an actuator or the like according to the signal, and as a result, the rotational speed of the prime mover is controlled. Such a series of steps is continuously performed until there is no deviation.

  In this way, in the speed control of the prime mover (synchronous generator), when a deviation occurs in the current value with respect to the target value, a negative feedback control method is employed in which control is performed so as to cancel the deviation. In the adjusting unit (not shown) in the speed governor 18 (see reference numeral 34 in FIG. 2), PID control is usually used, and parameters required for each control operation can be changed from the outside.

JP-A-9-215394 JP 2003-134897 A

  However, in the conventional speed control as described above, an automatic synchronizer is present in the control system, and the generator speed measurement signal and the system frequency signal input to the device are compared and determined, and the result is adjusted. There was a problem that control delay occurred due to the output to the speed machine. This delay in control means that, for example, the loss of steam volume increases when a generator at a thermal power plant is installed, and the amount of water consumed without being effectively used increases when a generator is installed at a hydropower plant. There was a problem. In particular, in the case of the latter hydropower plant, this is due to the fact that the water turbine (rotating body) has a large inertial force or the length of the water pipe is long, and the followability of the water amount adjustment control with respect to the speed fluctuation is poor. This may further contribute to the control delay that occurs.

  Therefore, the present invention solves the above-mentioned problem, and in the speed control of the synchronous generator, the speed control of the synchronous generator capable of inserting the synchronous generator into the power system without causing loss of fuel or water due to control delay. It is an object to provide a control device and a speed control method.

According to one aspect of the present invention, the object is provided with a prime mover, a synchronous generator coupled thereto, a circuit breaker provided in the power system and inserted when the synchronous generator enters the power system, and A speed / load setting device, a speed governor, and a prime mover control operation unit, wherein the speed / load setting device can be opened and closed in conjunction with turning on and off of the circuit breaker, and the circuit breaker is It has a changeover switch capable of switching between a system frequency signal from the power system and a target value signal from the speed / load setter depending on whether it is in the on state or the cutoff state, and the speed governor is When the circuit breaker is in the cut-off state, the system frequency is directly input from the power system as a target value. When the circuit breaker is in the on-state, the target value signal from the speed / load setter is used as the target value. receiving the input, Is achieved by the governor control system for a synchronous generator, characterized in that it is configured to deliver a manipulated variable signal to the engine control operating unit to match the rotational speed of the prime mover to the target value.

Furthermore, the object is achieved according to another aspect of the present invention, the prime mover and a synchronous generator connected thereto, a circuit breaker is turned on during parallel input operation to that the power system, the input of the circuit breaker A speed control method in a speed control device for a synchronous generator comprising a speed / load setter having a changeover switch that can be opened and closed in conjunction with a shutoff, a speed control device, and a prime mover control operation unit. When the circuit breaker is in the cut-off state by the changeover switch , the system frequency is directly selected from the power system, and when the circuit breaker is in the on-state, the target value signal from the speed / load setter is set as the target. A value is input to the speed governor as a value, and the speed governor sends a control operation signal to the prime mover control operation unit so that the rotational speed of the prime mover matches the target value. Speed control method Thus it is achieved.

  Since the speed control device of the present invention is used for speed control by directly introducing the system frequency signal as a target value into the speed governor without using the speed control device in the automatic synchronizer, as in the prior art. As a result, it is possible to reduce the loss of steam and water until the generator enters the power system.

It is a block diagram which shows an example of the speed control apparatus of the synchronous generator of this invention. It is a block diagram which shows an example of the speed control of the conventional synchronous generator.

  Hereinafter, an embodiment of a speed control device for a synchronous generator according to the present invention will be described in detail with reference to FIG. FIG. 1 is a block diagram showing an example of a speed control device for a synchronous generator according to the present invention obtained by improving the conventional example shown in FIG. In this figure, 2 is a prime mover, 4 is a synchronous generator, 6 is a system bus to which a synchronous generator is inserted, 8 is a generator breaker, and 10 is a voltage signal (frequency) of a small force proportional to the system voltage. Signal transformer, 22 is a frequency, voltage converter (hereinafter referred to as F / V converter), 24 is a changeover switch, 16 is a speed / load setting unit, 16a is a speed / load setting unit, Reference numeral 18 denotes a governor, 20 denotes a prime mover control operation unit, and 30 denotes a rotation detector. In FIG. 1, the illustration of components and connection lines not directly related to the present invention is omitted, but will be described below when necessary. Further, in FIG. 1, the same or common parts as in FIG. 2 are denoted by the same reference numerals. In FIG. 1, the rotation detector 30 is illustrated as being installed in the synchronous generator 4, but is installed in either the prime mover 2 or the synchronous generator 4 to detect the rotation speed. And

As shown in FIG. 1, the synchronous generator speed control device of the present invention is greatly different from FIG. 2 showing the conventional example in the following two points.
(1) In a state where the synchronous generator 4 is not juxtaposed to the power system 6, the system frequency signal is directly introduced into the governor 18 without going through the automatic synchronizer 12, and the target value in the speed control of the prime mover The point.
(2) The changeover switch 24 is used to change the target value of the speed control depending on whether the synchronous generator 4 is inserted in the power system 6 or not.

  The system frequency signal is equivalent to the system frequency when the system voltage of the power system 6 is transformed into a small power voltage signal having the system frequency in the instrument transformer 10 and further input in the F / V converter 22. Converted into a voltage signal (current signal). Here, as the F / V converter 22, a conventionally known device having a function of converting a voltage signal having a predetermined frequency into a DC voltage output or a DC current output corresponding to the frequency can be used. Whether the output is a DC current signal or a DC voltage signal can be determined as appropriate depending on the type of signal that can be input to the device to which the signal is sent. In this embodiment, the output is a DC voltage signal. .

  As the speed control device 18 in the present invention, a conventionally known device can be used. The speed governor 18 is usually configured to include at least a speed detection unit 31, a speed regulation rate setting unit 32, a deviation detection unit 33, an adjustment unit 34, and a prime mover control signal processing unit 36. The speed detection unit 31 uses an output signal from the rotation detector 30 provided in the prime mover 2 or the synchronous generator 4 as an electrical signal proportional to the actual rotation speed (in this embodiment, a DC voltage signal, which is a system frequency signal). It is preferable to match the type.) And output to the deviation detector 33. The deviation detection unit 33 is an addition / subtraction circuit that compares the magnitude of the output signal from the speed detection unit 31 with the input system frequency signal and further outputs the output signal from the speed regulation rate setting unit 32. It has a function for subtracting the size to find the deviation. Note that the speed regulation rate is an important constant that determines the sharing of the load when the motor is a turbine turbine in hydropower generation, for example, when entering the power system. In the setting unit 32, the motor control operation unit 20 The speed regulation rate is set based on the output signal from.

  The adjustment unit 34 has a function of performing feedback control, particularly PID control, in which the control of the rotational speed of the prime mover 2 is performed by comparing the system frequency signal, which is a target value, with the output signal from now on. Parameters for the PID control operation can be set as appropriate. Normally, the parameters are set in advance. The prime mover control signal processing unit 36 is configured to amplify a control operation signal output to the prime mover control operation unit 20. Note that an apparatus such as a signal selector can be further provided in the output path leading to the motor control signal processing unit 36 of the adjusting unit 34 as necessary.

  As shown in FIG. 1, the speed / load setting device (65F / 65P) 16 includes a speed / load setting unit 16a that performs its original function and a changeover switch 24. The speed / load setting unit 16a receives an input of a system frequency from the power system 6 (not shown), and further adds / subtracts an amount corresponding to a preset frequency difference to output it as a target value signal. The changeover switch 24 has an a-contact switch section 24a and a b-contact switch section 24b, and these sections are configured to open and close in conjunction with the turning on and off of the generator breaker 8, respectively. ing. After entering the power system, the target value signal is sent from the speed / load setting device (65F / 65P) 16 to the speed governor 18 via the a contact switch 24a of the changeover switch 24. In the present embodiment, the speed / load setting device 16 includes the changeover switch 24, but both can be configured as separate devices.

  Next, the operation of the synchronous generator speed control device of the present invention will be described. When the synchronous generator 4 is not juxtaposed to the power system 6, the circuit breaker 8 is not turned on and is open, and in conjunction with this, the b contact switch 24b of the changeover switch is closed, the a contact switch The part 24a is in an open state (see FIG. 1). The frequency signal transformed from the power system 6 through the instrument transformer 10 into a small power AC voltage signal having a system frequency is converted into a DC voltage signal by the F / V converter 22 as a system frequency signal, and the contact b It is sent into the speed governor 18 through the switch unit 24b.

  On the other hand, the rotation speed of the synchronous generator 4 is detected by a rotation detector 30 disposed therein, and a rotation speed signal proportional to the rotation speed is output from the detector toward the governor 18. The rotation speed signal is converted into a DC voltage signal corresponding to the actual rotation speed of the prime mover by the speed detection unit 31 in the speed governor 18 and output to the deviation detection unit 33. In the deviation detector 33, addition / subtraction is performed between the system frequency signal, the signal corresponding to the actual rotational speed of the prime mover, and the output signal of the speed regulation rate setting unit 32, and a deviation between these signals is detected. This deviation is output as a deviation signal from the deviation detector 33 and sent to the adjustment unit 34.

  In response to the input of the deviation signal, the adjustment unit 34 performs a control calculation based on a preset PID control parameter and other set values, and an operation amount signal is sent to the prime mover control signal processing unit 36 so as to eliminate the deviation. Is output. In the prime mover control signal processing unit 36, when the manipulated variable signal is sent to the prime mover control operation unit 20, the signal is appropriately subjected to processing such as amplification.

  The prime mover control operation unit 20 receives an operation amount signal and operates an operation device such as an actuator in accordance with the magnitude. For example, in an ordinary power plant such as hydropower, thermal power, and nuclear power, such an operating device is connected to a control valve provided in a water pipe or a steam pipe, and the operating equipment is selected according to the magnitude of an operation amount signal. By operating the control valve, the control valve is opened and closed accordingly, and the amount of water flow and the steam flow rate can be increased or decreased. As a result, the rotational speed of the prime mover 2 such as a turbine turbine or a steam turbine, and consequently the synchronous generator 4 connected thereto, is controlled.

  By performing the series of control operations continuously, the rotational speed of the prime mover 2 settles within the range of the set value for the system frequency and substantially matches the system frequency.

  When the frequency of the power generation output of the synchronous generator 4 falls within a predetermined set value range and substantially matches the system frequency, and the synchronous parallel condition regarding voltage and phase is also satisfied, the automatic synchronizer 12 is connected to the circuit breaker 8. Issue input command signal. In response to this command signal, when the circuit breaker 8 is turned on and the synchronous generator 4 is inserted into the power system 6, in the changeover switch 24, the b contact switch 24 b is opened and the a contact switch 24 a is closed. Thus, thereafter, the speed control of the prime mover 2 is performed so that there is no deviation between the target value signal output from the speed / load setter 16 and the prime mover input (such as the opening signal of the flow control valve). It will be.

  Examples of the prime mover in the present invention include a turbine turbine in a hydroelectric power plant, a steam turbine in a thermal power plant and a nuclear power plant, and an engine in an engine generator.

  As described above, according to the speed control device and the speed control method of the synchronous generator of the present invention, the system frequency signal is directly input to the speed control device without using the automatic synchronization device as in the prior art, Since the determination is made in comparison with the rotational speed signal of the prime mover, the conventional control delay does not occur, and as a result, the loss of the flowing water amount and the steam flow rate in the power plant can be greatly reduced.

  Also, the synchronous generator speed control device according to the present invention sets the target value of the speed control of the synchronous generator by the changeover switch and the existing system frequency depending on whether the synchronous generator is installed in the power system. The output from the speed / load setter is switched, and the conventional uniform speed control can be performed during parallel operation to the power system. As described above, the present invention can be implemented only by improving a part of the conventional speed control device, so that the remodeling cost can be suppressed at a low cost.

  The synchronous generator speed control device and the speed control method of the present invention provide a synchronous generator control method that must be synchronously parallel to the power system in a thermal power plant, a hydroelectric power plant, a nuclear power plant, or various private power generators. Applicable to speed control.

2 prime mover
4 Synchronous generator 6 System bus 8 Circuit breaker 10 Instrument transformer 22 Frequency, voltage converter (F / V converter)
24 selector switch 16 speed / load setting device 18 speed governor 20 prime mover control operation unit 30 rotation detector 31 speed detection unit 33, 35 deviation calculation unit 34 adjustment unit 36 prime mover control signal processing unit

Claims (2)

A prime mover, a synchronous generator connected thereto, a circuit breaker provided in the power system and inserted when the synchronous generator enters the power system, a speed / load setting device, and a speed governor; A motor control operation unit,
The speed / load setting device can be opened and closed in conjunction with turning on / off the circuit breaker, and the system frequency signal from the power system and the speed / load setting depending on whether the circuit breaker is turned on or off. Has a changeover switch that can be switched between the target value signal from the instrument,
The speed governor is
When the circuit breaker is in a cut-off state by the changeover switch, the system frequency is directly input as a target value from the power system,
When the circuit breaker is in the on state, a target value signal from the speed / load setting device is received as a target value,
A speed control device for a synchronous generator configured to send an operation amount signal to the prime mover control operation unit so as to make the rotational speed of the prime mover coincide with the target value. Speed / speed having a prime mover, a synchronous generator connected thereto, a circuit breaker that is turned on during parallel operation to the power system, and a changeover switch that can be opened and closed in conjunction with turning on and off of the circuit breaker. A speed control method in a speed control device for a synchronous generator including a load setting device, a speed control device, and a prime mover control operation unit,
When the circuit breaker is in the cut-off state by the changeover switch , the system frequency is directly output from the power system, and when the circuit breaker is in the on-state, the target value signal from the speed / load setter is set to the target value. Is input to the speed governor, and the speed governor sends a control operation signal to the prime mover control operation unit so as to make the rotational speed of the prime mover coincide with the target value. Speed control method.

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