JPH0621399U - Generator capacity limiter - Google Patents

Abstract

(57) [Summary] [Objective] The present invention reduces the active power and / or the reactive power when the apparent power of the generator exceeds the generator capacity, and the generator is operated at the rated capacity or more. Prevent. Configuration: A conversion unit 3 detects active power and reactive power of a generator 1 to convert a signal, and a calculation unit 4 calculates apparent power based on the signal obtained by the conversion unit 3. Based on the apparent power When the generator 1 exceeds the generator capacity, the control unit 5 issues a command to the governor controller 8 to reduce the active power or a process to issue the command to the exciter 6 to reduce the reactive power. At least one of the processes is performed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a generator capacity limiting device that controls an exciting device, a governor control device, and the like in a power plant so that the amount of power generated by the generator does not exceed the generator capacity.

[0002]

[Prior art]

 In a run-of-river type hydropower plant, there are many operations that generate electric power according to the inflow amount, so when the inflow amount is large, the operation is often limited to the generator capacity.

Then, when the effective head and the system voltage are constant, the active power of the generator is adjusted by adjusting the guide vane opening degree by the speed governor control device to control the inflow amount to the turbine. There is.

Further, the reactive power of the generator is adjusted by controlling the field current of the generator by the field device when the system voltage is constant.

As described above, the active power adjustment and the reactive power adjustment of the generator are performed by independent primary regulators.

[0006] Generally, a water level adjuster is used as a secondary adjuster for controlling the active power of the generator. This is to make the flow rate and the turbine inflow rate the same, that is, the flow rate. This is a device that aims to obtain active power according to the flow rate (generally, regulating pond water level) and the opening of the guide vane, and the guide vane is compared with the speed governor controller. Sending an open / close command.

As a secondary regulator for adjusting the reactive power of the generator, a power factor adjusting device is generally used, which detects the active current and the reactive current of the generator, and detects the reactive current with respect to the active current. This is a device whose purpose is to control the power factor of the generator to be constant.It issues a command to the exciter to change the field amount and changes the reactive power to control the power factor. .

[0008]

[Problems to be solved by the device]

 However, in such a power generation system, if the effective head increases due to a rise in the water level of the regulating pond or a drop in the water level of the discharge channel, the amount of power generation will increase for the same guide vane opening. Since the automatic power factor adjustment device keeps the power factor constant, the field current increases and the reactive current increases, which may increase the apparent power and exceed the generator capacity.

Further, when the system voltage rises for the same guide vane opening, if the active power is constant, the reactive power increases, resulting in an increase in apparent power. There is a risk that the generator capacity will be exceeded.

As described above, in the conventional power generation system, only the active power is controlled by adjusting the guide vane opening degree by the water level adjusting device, and the power factor is controlled to be constant by the power factor adjusting device. Therefore, the conventional regulator cannot manage the apparent power determined by the active power and the reactive power.

Therefore, in the case where the generator is operated at the maximum capacity, the problem that the generator exceeds the rated capacity when the above-mentioned effective head fluctuation or system voltage fluctuation occurs was there.

In view of the above circumstances, the present invention reduces the effective power and / or the reactive power when the apparent power of the generator exceeds the generator capacity, and the generator is operated at the rated capacity or more. It is an object of the present invention to provide a generator capacity limiting device that can prevent the occurrence of the electric shock.

[0013]

Means for Solving the Problems To achieve the above object, a generator capacity limiting device according to the present invention comprises a converter for detecting effective power and reactive power of a generator and converting the signal, and a converter. When the generator exceeds the generator capacity based on the apparent power obtained by this arithmetic unit and the apparent power obtained by this arithmetic unit, the effective power is supplied to the governor controller. And a control unit that performs either one of an output command process for lowering the reactive power and an output command process for lowering the reactive power to the exciter.

[0014]

[Action]

 In the above configuration, the converter detects the generator active power and reactive power and performs signal conversion, the calculator calculates the apparent power based on the signal obtained by the converter, and the apparent power is generated based on the apparent power. If the generator exceeds the generator capacity, at least one of the process of issuing a command to reduce the active power to the governor control device or the process of issuing a command to reduce the reactive power to the exciter by the control unit. Is carried out.

[0015]

【Example】

 FIG. 1 is a block diagram showing an example of a power generation system to which an embodiment of the generator capacity limiting device according to the present invention is applied.

In the power generation system shown in this figure, active power and reactive power of the generator 1 are input to the generator capacity limiting device 2.

In this generator capacity limiting device 2, after converting each of these inputs into a signal by the conversion unit 3, the calculation unit 4 calculates the apparent power and also performs the comparison calculation to generate the apparent power of the generator. Determines whether the generator has exceeded the rated capacity of the generator, and if it exceeds the rated capacity of the generator, the controller 5 gives a reactive power down command to the exciter 6 and opens the contact 10. Then, the reactive power raising command from the power factor adjusting device 7 is locked, or the active power lowering command is given to the governor control device 8, and the contact 11 is opened to raise the active power from the water level adjusting device 9. Lock the command.

Here, for simplification, it is assumed that a “reactive power priority mode” and a “active power priority mode” are provided as control modes, and any one of these modes is arbitrarily switched.

When the “reactive power priority mode” is set, when the apparent power of the generator exceeds the rated capacity of the generator and reaches the position P21 shown in FIG. 2, the generator capacity limiting device 2 controls the water level. The active power increase command from the device 9 is locked, and the active power is reduced to the point P22.

In this case, since the power factor is behind the set power factor of the power factor adjusting device 7, the power factor adjusting device 7 keeps the power factor constant, so that the reactive power is lowered to the point of P23. At point P23, since the generator capacity returns to within the rated capacity, the active power is increased until the water level adjusting device 9 is unlocked and the generator capacity limiting device operates again.

Thereafter, the generator capacity limiting device 2 repeats this operation and finally converges on the point P24, that is, the generator rated capacity on the power factor set by the power factor adjusting device 7. Stabilize.

Next, if the “active power priority mode” is set and the apparent power of the generator exceeds the rated capacity of the generator and reaches the point P31 shown in FIG. The reactive power increase command of the rate adjusting device 7 is locked, and the reactive power is lowered to the point of P32, whereby the active power is prioritized and stabilized at the power factor at the generator rated capacity.

Further, as shown in FIG. 4, when the point P41 is reached, the generator capacity limiting device 2 lowers the reactive power to the point P42, and at this time, as in the case of P42, as in the above-described operation. At the point, since the generator rated capacity is still exceeded, the active power increase command of the governor control device 8 is further locked, and the active power is reduced to the point of P43, whereby the power factor increases to "1". Stabilize operation with active power equivalent to the rated capacity of the machine.

As described above, in this embodiment, when the apparent power of the generator 1 exceeds the generator capacity by the generator capacity limiting device 2, at least one of active power and reactive power can be reduced, This can prevent the generator 1 from operating above the rated capacity.

[0025]

[Effect of device]

 As described above, according to the present invention, when the apparent power of the generator exceeds the generator capacity, at least one of the active power and the reactive power is reduced to operate the generator at the rated capacity or more. Can be prevented.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a power generation system using an embodiment of a generator capacity limiting device according to the present invention.

FIG. 2 is a schematic diagram showing an operation example of the generator capacity limiting device shown in FIG.

FIG. 3 is a schematic diagram showing an operation example of the generator capacity limiting device shown in FIG.

FIG. 4 is a schematic diagram showing an operation example of the generator capacity limiting device shown in FIG. 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 generator 2 generator capacity limiting device 3 conversion unit 4 computing unit 5 control unit 6 excitation device 7 power factor adjustment device 8 speed governor control device 9 water level adjustment device 10, 11 contacts

Claims (1)

[Scope of utility model registration request] 1. A conversion unit for detecting active power and reactive power of a generator and converting the signal, a calculation unit for calculating apparent power based on a signal obtained by the conversion unit, and a calculation unit obtained by this calculation unit. When the generator exceeds the generator capacity based on apparent power, either output command processing to reduce active power to the governor controller or output command processing to reduce reactive power to the exciter A generator capacity limiting device, comprising: